CA1162046A - Burner and process for the partial oxidation of slurries of solid carbonaceous fuels - Google Patents

Abstract

ABSTRACT
A burner for the partial oxidation of pumpable slurries of solid carbonaceous fuels in which the pumpable slurry of solid carbonaceous fuel in a liquid carrier is passed in liquid phase through one passage of a burner comprising a retracted central coaxial conduit, an outer coaxial conduit with a converging orifice at the downstream tip of the burner and, optionally, an inter-mediate coaxial conduit. The downstream tips of the central conduit and the intermediate conduit, if any, are retracted upstream from the burner face a distance of respectively two or more say 3 to 10 for the central conduit, and about 0 to 12 say 1 to 5 for the intermediate conduit times the minimum diameter of the converging orifice of the outer conduit at the burner tip. A pre-mix zone is thereby provided comprising one or more, say 2 to 5 co-axial pre-mix chambers in series. The free oxygen-containing stream is passed through a separate passage of the burner into the pre-mix zone, in which mixing takes place with the slurry of solid carbonaceous fuel and liquid carrier. From 0 to 100, say about 2 to 80, volume % of the liquid carrier may be vaporized in the pre-mix zone. The multiphase mix-ture of reactants is then discharged into the reaction zone of the free-flow partial oxidation gas generator by way of the converging orifice of the outer conduit at the burner tip. Synthesis gas, fuel gas, or reducing gas is thereby produced.

Description

` ~ 1 162~4~ D.76,187-FB
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This lnv~n~ion relates to the ~2nufacture of gaseous mixtures comprising H2 and CO, e.g., synthesis g2s, fuel gas, and reducing Oas by the partial oxidation of pumpable slurries of solid carbonaceous fuels in 2 liquid : : ~
;~ - 5- c2rrier 2nd/or liau~d or Oaseous hydroczrbon fuel. In one of its more specific aspects, the present inveniion relates to an imoroved burner for ~uch ~ s manuf2cture.
~; Annulus-type burners have been employed for introducing liquid hydrocarbonaceous fuels into a pbrtial lO. oxidation gas generator. For example~, our U.S.
~ ~:
Patent 3,~528,930 show3 a single 2nnulus burner, and~
oul U.S. ~Patents 3,758,037 and 3,847,564 sho~;doukle nn~1us~ burners. To obtain proper mixing, atomizat~lon; and stabillty or operation a burner is sized for a s~eclflo throughput.~ Should the requlred output or~product;gas chan2e subst~antial7y, wi~h prior-~rt burners, shut-down of ;the~ system~is~req;uired in order to replace the prior-art burner~with~one~of proper size;. This~problem~is avolded and~
c~ostl~ shut-downs are avolded~by the sub~ect Durner whlch operate at varying l~vels of output while retainlng fflclencD~;and;staDility.~ he more~comple~. process for pre:qe~tln6~a gas cenerator by me2ns cf a Dreheat burner, removinO the~Dreheat burner from ~the ~asifier, and ~nsertinO

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a separate production burner is descri.bed in our United States Patent No.
4,113,445.
The nozzle tip of the central conduit of such prior art burners is substantially flush with or close to the face of the burner, and substantially no premixing of the reactants takes place upstream from the face of the burner.
Accordingly in such burners, substantially all of the atomizing and mixing of the fuel stream with the oxygen stream takes place downstream from the face of the burner.
In the partial oxidation of liquid phase slurries of solid carbonaceous fuels. to produce synthes.is gas, fuel gas, or reducing gas, problems of combust-ion instability and poor efficiency which may be encountered with flush face burners have been eliminated by employing the subject invention.
This invention provides a burner for intimately mixing together at least two separate feedstreams comprising a pumpable slurry of solid carbonaceous fuel in a liquid carrier, and a feedstream of free-oxygen containing gas, with or without admixture with a temperature moderator to produce a multiphase mixture for reaction by partial oxidation in a gas generator to produce raw synthesis gas, fuel gas or reducing gas comprising mixtures of l-12, C0, C02 and at least one material from the group H20, N2, A, CH4, H2S, and COS, and entrained particulate matter characterized by: central flow means coaxial with the central longitudinal axis of the burner and having upstream inlet means through which a first feed-stream or feedstreams may be separately introduced, and downstream outlet means that discharges into a central coaxial pre-mix zone; an outer first coaxial conduit concentric with and surrounding said central flow means and havillg an ~p-stream inlet through which a second feedstream may be separately introduced and a coaxial circular exit outlet terminating said outer conduit at the do~nstream tip of the burner and comprising a partially converging frusto-conical rear .

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portion and a right cylindrical front portion whicll terminates at the downstream face of the burner, and the height of tlle front cylindrical portion of said exit nozzle is in the range of about 0.1 to 1.0 times it~ O-YIl diameter, an annular shaped face-cooling cllamber surrounding said exit outlet at the burner tip;
wherein the do~Ynstream termination of said central flow means is retracted up-stream from the downstream face of the burner a distance of two or more times the minimum diameter of said outer conduit downstream outlet to provide said central pre-mix zone comprising one or more communicating pre-mix chambers in tandcm and coaxial with the central longitudinal axis of the burner; and means for supporting said central flow means and outer conduit with respect to each other to provide a passage or passages theTebetween through which said second feestream may separately pass concurrently with said first feedstream(s) into said central pre-mix zone where said feedstreams are intimately mixed together and a controlled amount in the range of about 0 to 100 vol. % of the licluid car-rier is vaporized without burning to produce said multiphase mi~ture prior to being discharged through said outer conduit exit outlet at a discharge velocity hich is greater than the flame propagation velocity.
In a second aspect this invention provides a burner for the partial oxidation of reactant fuel feedstream selected from the group consisting of a pumpable slurry of solid carbonaceous fuel in a liquid carrier, liquid or gaseous hydrocarbon fuel, and mixtures thereof with a reactant feedstream of free-oxygen containing gas, comprising: a central conduit, said central con~uit being closed at the upstream end and having an unobstructed downstream circular exit orifice at the tip of the burner; an outer conduit coaxial and concentric with said central conduit along its length and in spaced relationshiptherewith and forming an annular passage therebetween, said outer conduit and annular passage being closcd at the upstream end and having an unobstructod downstream anllular exit - 2a -

2 0~L 6 orifice at the tip of the burner and wherein the central longitudinal axis of the annular passage is parallel to the central longi~udinal axis of the burner throughout its length; a central bunch of tubes passing through the closed end of said central conduit and making a gastight seal therewith, the tubes of said central bunch of tubes extending down said central conduit and having upstream inlet means for introducing a f.irst feedstream and downstream ends through which said first feedstream is discharged, and wherein the downstream ends of said central bunch of tubes are retracted upstream from the burner face a distance of about 0 to 12 times the minimum diameter of the central conduit exit orifice at the tip of the burner, means for spacing and supporting said central bunch of tubes with respect to the inside wall of said central conduit and to each other, and upstream inlet means for introducing a second feedstream into said central conduit and the passages and interstices when present between the central bunch o tubes; an annular bunch of ~.ubes passing through the closed end of said annu-lar passage and making a gastight seal therewith, the tubes in said annular bunch of tubes having upstream inlet means for introducing a third eedstream into.said tubes and downstream ends through which said third feedstream is discharged, and wherein said downs~ream ends of said annular bunch of tubes are retracted upstream from the burner face a distance of about 0 to 12 times the minimum width of the annular exit orifice at the tip of the burner, means for supporting said annular bunch of tubes with respect to the inside wall of said annular passage and to each other, and upstream inlet means for introducing a fourth feedstream into said annular passage and the passages and interstices when present between the annular bunch of tubes in said annular passage; and wherein ignition of mixtures of the reactant feedstreams takes place downstream from the face of the burner.
The subject novel burner includes an internal pre-mix ~one in which two ~ 2b -20~

or three feedstreams tb the react~on zone of a partial oxidation gas generator are mixed together without ignition and optionally pre-heated to vaporize from 0 to 100 vol. % of the liquid carrier. The burner comprises a retracted central coaxial conduit and an outer coaxial conduit with an annular passage therebetween.
A converging exit noæzle may terminate the outer conduit at the do~nstream end of the burner. In another embodiment, an intermediate coaxial conduit may be interposed b~tween the central and outer conduits thereby providing intermediate and outer annular passage~. Optionally~ the intermediate conduit may contain a plurality of small diameter holes or passages to permit at least a portion of the gaseous material -- ~c --1 1~20~

flowing in the outer annular passage to pass through and mix with the materials flowing through the intermediate annular pass~ge and/or the pre-mix zone.
The tip of the inner central conduit and the interli~ediate conduits if any, may be retrac~ed upstream from the face of the burner a distance of respectively two or more tlmes, say 3 to 10 times, and 0 to 12 times, say 2 to 5 times the minimum diameter of the converging exit nozzle at the tip of the burner, thereby providing a pre-mix zone 10. comprising one or more, say 2 to 5 coaxial pre-mix chambers in series. ~he pre-mix zone is locaied bet~7een the down-stream tip of said central conduit and the face of the burner at the downstream end. The reactant streams are separately introduced into the pre-mix zone by way of said 15. central conauit and annular passage or passages. In the pre-mix zoner the reactants are thoroughly mixed together and simultaneously about 0 to lO0 vol. ~, say about 2 to 80 vol.
% of the liquid carrier may be vaporized. In one embodiment, the mixture leaving one pre-mix chamber may expand into the next pre-mix chamber in the line. The change in velocity of the mixture flowing through the successive pre-mix chambers assures a thorough mixing of the feeQ streams prior to discharge from the burner. The multiphase mixture may be passed through ~ converaing exit nozzle on the downstream end of 2~ the outer conduit at a discharge velocity which is greater than the flame propagating velocity.

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A further emDodiment comprises a burner having a high turndown feature and comprising: a central conduit that terminates in an unobstructed circular exit orifice at the burner face; a central bunch of parallel tubes that 5. extend longitudinally through said central conduit and having downslream ends which are retracted upstream from the burner face, preIerably by a distance of about 3 to 10 times the minimum diameter of the central conduit exit orifice; an outer conduit coaxial with said central conduit and forming lG an annular passage therewith that terminates in an unobstruct-ed annular orifice at the burner face; and an annular bunch of parallel tubes that extend longitudinally throuqh said annular passage and having downstream ends which are retract-ed upstream from the burner face a distance of about 0 to 12 75. times, e.g. 3 to 10 times, the minimum width of the annular exit orifice.
Separate portions of the fuel feed may be passed through the central bunch of tubes and/or the annular bunch of tubes while simultaneously, the stream of free-oxygen 20 containing gas is passed through the corresponding central conduit and/or the annular passage which respectively surrounds the bunch or bunches of tubes in use. Temperature moderators may be optionally in admixtur~ with the gaseous oxidant - and/or the fuel feedstreams. By this means the free-oxygen 25. containing gas may be introduced into the interstices between the tubes and more elficient mixing of the reactant streams is achieved. Alternately, separate portions of the free-oxygen containing gas may be passed through the central and/or annular bunches of tubes while simultaneously the ' f~el ~eed is p2ssed through the corresponding central conduit and/or annular passage which respectively surroun2s the bunch or bunches of tubes in use.
In another emboaiment of the burner, aoditional 5. mixing of the re~ctant streams may be obtained by providins one or more cC2~:ial cylindrical shcped pre-mi~ ch2mbers in series in the central conduit and/or one or more cnnular sh2ped pre-mix chambers in series in the annular passage.
In the pre~mix chambers, the feedstrecms to the reaction zone of a partial oxidation cas generator cre mi~ed together without ignition and optionally pre-heated to ~aporize from 0 to 100 volume percent of the liqui~ carrier. Jets of a saseous r,aterial i.e. steam, free-oxygen containing gas, C02, N2, recycle product gas, and mixtures thereof may be 15. optionally introduced into at least one of the pre-mix chambers. ~he change in velocity of the mixture flowing through the successive pre-mix chambers assures a thorough , mixing of the feedstreams prior to discharge from the burner. The multiphase mixture is passed, for example, 20. through a converging exit orifice at the downstream end of the central conduit and/or annular passage at a discharge velocity which is greater than the flame propagating velocity.

, ManUal or automatic control means may be provided for adjusting the throughput levels of the fuel and oxidant 25. streams through the subject burner - up or down - to produce many levels of gasifier output while retaining efficiency and stability.
Starting up the partial o~idation gas generator is simplified by a new procedure which emplo~s the subject 30. burner only. Separate preheat burners are thereby eliminated.

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A yet further embodiment may comprise a swirl burner having pre-mix and/or high turndown features. By means of the subject burner separate swirling feed streams may be intimately mixed together to produce a multi-phase mixture 5- for reaction in a partial oxidation gas generator compris-ing: a central bundle of open-ended helical tubes whose central longitudinal axis is coaxial with the c~ntral longitudinal axis of the burner and comprising a plurality of helical tubes having inlet portions in communication 10- with upstream inlet means by which a first reactant feed stream may be introduced and then split into a plurality of separate streams which pass down through said central bundle of helical tubes and are then discharged through the downstream ends of said tubes; a first coaxial cylindrical 15- conduit concentric with and surrounding said central bundle of helical tubes, said first conduit being closed near the upstream end so that the inlet portions of said plurality of helical tubes may pass through and make a gastight seal therewith and having an unobstructed circular downstream 20- outlet at the tip of the burner; upstream inlet means in communication with said first con~uit through which a second reactant feed stream may be separately introduced : and split into a plurality of swirling streams which may pass down through a plurality of related helical-shaped 25- passages formed in the cylindrical space that surrounds said central bundle of helical tu~es and/or through the interstices, if any, between said helical tubes; and means for supporting said central bundle of helical tubes with respec~ to said first conduit and each other; and wherein the downstream tips of said central bundle of helical tubes are retracted upstream from the downstream face of the burner a distance of about 2 or more, e.g. about 3-10 times, the minimum diameter of said first conduit downstream outlet; and said first and second swirling reactant feed strea~ms impinge together and are intimately mixed~
When the two swirling reactant streams impinge, either upstream in a pre-mix zone or downstream from the ~, l 1~2~4~

face o~ the burner, intimate mixing and atomization may take place. The combustion efficiency of the burner is thereby improved.
In another embodiment, the burner includes a 5. coaxial annular bundle of helical tubes surrounding said first conduit and a plurality of related annular passages formed in the annular space occupied by said annular bundle of helical tubes. By this means, flow through the burner may be easily turned up or down. For example, the burner 10. may be operated with the first and second feed streams passing through the central bundle of helical tubes and the related surrounding passages and/or with the second and third feed streams passing through the annular bundle of helical tubes and the related surrounding passages, 15. When a pre-mix zone is employed, the reactants are thoroughly mixed together and simultaneously about 0 to 100 vol. %, say about 2 to 80 vol. % of the liquid carrier may be vaporized~ In one embodiment, the mixture leaving one pre-mix chamber expands into the next pre-mix chamber 20. in the line as described above.
Specific embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:
Figure 1 is a general illustration of the burner 25. assembly;
Figure 2 is a diagrammatic longitudinal cross-sect-ion through the downstream end of the burner, taken at line A-A of Figure 1 and showing an embodiment of a burner accord-ing to the invention;
30. Figure 3 is a view of another example of the tip exit orifice at the downstream tip of coaxial outer conduit 16 shown in Figure 2;
Figure 4 is a view of another example of the down-stream tip of outer conduit I6 shown in Figure 2 which the 35~ exit orifice is made from an erosion-resistant material such as silicon carbide or tungsten carbide 35;
Figure 5 is a diagrammatic longitudinal cross-sect-ion through the downstream end of the burner, taken at line ~ ~20~

~-A of Figure 1 which shows another embodiment of the burner in which there is one annular passage 17 and the pre-mix zone comprises two free-flow coaxial chambers 25 and 40 in series;
5. Figure 6 is a diagrammatic longitudinal cross-section through the downstream end of the burner, taken at line A-A of Figure 1 and showing another embodiment of the burner in which there are two annular passages 17 and 51 and the pre-mix zone comprises three free-flow coaxial pre-mix 10. chambers 25, 40, and 41 in series;
Figure 7 is a diagrammatic vertical longitudinal schematic representation showing another embodiment of the invention;
Figure 8 is a transverse section through line8-8 15. of the embodiment of the burner shown in Figure 7;
Figure 9 is a schematic representation of one em-bodiment of the invention showing control means for rapidly changing throughput levels - up or down;
Figure 10 is a vertical longitudinal schematic 20. representation of a further embodiment of the burner showing two central and annular pre-mix chambers in series and central and annular bunches of tubes with their ends re-~ :trated upstream from the face of the burner;
.: Figure 11 is a diagrammatic longitudinal cross-section through a further embodiment of the invention in -the form of a swirl burner employing a central bundle of helical ~: tubes with retracted ends to provide a pre-mix chamber;
Figure 12 is a view of another example of the downstream outlet of conduit 16 shown in Figure 11 and, : Figure 13 is a vertical longitudinal schematic representation of a yet further embodiment of the subject burner having a high turn-down capability, in which central and annular bundles of helical tubes with downstream retract-: ed ends provide two central and annular pre-mix chambers in ~ 3' sexies.

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g The present invention involves a novel burner for the manufacture of gas mixtures comprising H2, C0, C02 and at least one material selected from the group consisting o~
H20, N2, A, CH4, H2S and COS, such as synthesis gas, fuel gas, and reducing gas, by the partial oxidation of a reactant stream selected from the group consisting of a pumpable slurry of solid carbonaceous fuel in a liquid carrier, liquid or gaseous hydrocarbon fuel, and mixtures thereof with or with-out admixture with a temperature moderator, with a reactant stream of free oxygen containing gas with or without admixture with a temperature moderator. The product gas mixture is produced in the reaction zone of a noncatalytic, refractory-lined, free-flow partial oxidation gas generator, such as describe~ in our U.S. Patent No. 2,809,1-4 at a temperature in the range of about 1700 to 3500F. and a pressure in the range of about 1 to 300 atmospheres, such as about 5 to 250 atmos-pheres, say about 10 to 100 atmospheres.
Problems of combustion instability and poor efficiency may be encountered when prior art flush face burners are used for the gasification of li~uid phase slurries of solid carbon-aceous fuels. For example, at times varying from start-up to 10 hours after start-up, with coal-water slurry feeds the following changes in the operation of the generator could occur: (1) the te~perature measured at the top of the reac*icn zone may rise rapidly while there may be little or no rise of temperature at the bottom; (2) the product gas rate may decrease; at the same time, the C02 content of the gas may incxease; (3) the particle size and amount of unconverted solids may increase. It may not be possible to correct the aforesaid rise in temperature in the reaction zone or the other changes mentioned by decreasing the oxidation rate or increasing the slurry rate. Further, said changes may occur re rapidly at higher pressures. The aforesaid problems may indicate poor mixing of the feeds. Purther, part o~ the coal may be passing through the gas generator ~ithout contacting significant amounts of ox~ygen and the coal may be only ~ ~620~6 devolatilized and fused. In such case, unreacted oxygen in the reaction zone may then react with the product gas.
These problems and others are avoided by employing the subject novel burner in which two or three feedstreams to the reaction zone of a free-flow partial oxidation gas gener-ator are mixed together without igniting in an internal pre-mix zone and optionally pre-heated to vaporize from O to 100 vol. % of the liquid carrier of the slurry feedstream. For example, a slurry of solid carbonaceous fuel in water is passed irlto the burner in liquid phase. There it is thoroughly mixed with a separate stream of free-oxygen con-taining gas, and optionally with a temperature moderator.
The feedstreams are mixed together in a pre-mix zone located within the burner upstream from the exit nozzle. Optionally, the feed slurry may be simultaneously heated in the pre-mix .
~one of the burner by direct heat exchange with the other ; feedstreams and/or indirect heat exchange with a portion of the combustion gases that are recirculating on the outside of the burner. By this means, from O to 100 vol. % such as about 2 to 80 vol. ~, say about 5 to ~5 vol. % of the liquid carrier in the slurry feed may be vaporized before the multi-phase mixture of reactants leaves the pre-mix zone by way of a converging exit nozzle at the downstream end of the burner and directly enters the reaction zone of the partial oxida-tion gas generator.
Embodiments of the subject burner include single and double annulus types with one or more, sa~ 2 to 5 coaxial cylindrically shaped pre-mix chambers in series. In one embodiment, the mixture leaving one pre-mix chamber expands into the next pre-mix chamber in the line. The change in velocity of the mixture flo~ing through the successive pre-mix chambers assures a thorough mixing of the feedstreams prior to discharge from the burner. The mixture is acceler-ated through the converging exit nozzle at the downstream end of the burner directly into the reaction zone of the partial oxidation gas generator.

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Pumpable slurries ir. liquid phase having a dry solids content in the range of about 30 to 75 wt. %, say about 40 to 60 wt. ~ are passed through an inlet passage of the sub-ject burner. The inlet temperature of the slurry is in the range of about ambient to 500F., but below the vaporization temperature of the liquid carrier at the given inlet pressure in the range of about 76 to 4500 psia, say about 150 to 1500 psia~
In one embodiment, the liquid slurry comprises 40 to 60 wt. ~ of solid carbonaceous fuel in liquid C02.
In another embodiment, a single annulus pre-mix burner is employed and the feedstream comprises a slurry of liquid hydrocarbonaceous material and solid carbonaceous fuel. H20 in liquid phase in the amount of about 5 to 95 wt. % may be mixed with the liquid hydrocarbonaceous carrier, for example as an emulsion. Alternately, a portion of the H20 i.e., about 0 to 25 vol. % may be introduced as steam in admixture with the free-oxygen containing gas.
For all embodiments of the subject retracted central conduit single and multi-annulus~type burners, the downstream tip of the central and intermediate conduits are retracted upstream from the face of the burner a distance of respect-ively o~ two or more times say 3 to 10 for the tip of the central conduit, and 0 to 12, say 1 to 5 for the tip of the intermediate conduit times the minimum diameter of the con-~ ~ verging ori~ice of the outer conduit at the burner tip. In ; ~ one embodiment the set-back for the tip of the intermediate conduit is greater than the set-back for the tip of the center conduit.
The set-back provides space for a pre-mix zone. The pre-mix zone comprises one or more, say 2 to 5 coaxial pre-mix chambers in series. When supplemental steam is employed as a temperature moderator, all of the steam may be passed through one passageway. Alternatively, about 0 to ~5 volume percent of the steam may be mixed with the stream of free-i t6204~

oxygen containing gas and passed through one passag~way, and the remainder of the steam may be passed through the remain-ing passageway.
The subject single and multi-annulus pre-mix burners may be operated with the feedstreams passing through alter-nate passages in the burner. Typical modes of operation are summarized in Tables I to III below.
Table I lists the materials being introduced into the gasifier by way of the burner and their corresponding symbol.
The solid carbonaceous fuel (B), water (C), and liquid hydro-carbonaceous material (E) may be mixed together in various combinations upstream from the burner inlet to produce a pumpable slurry which may be introduced into the burner and then passed through one of the several free-flow passages of the burner as shown in Table II for the single annulus pre-mix burner (see Figures 2 and 5); and as shown in Table III
for the double annulus pre-mix burner (see Figure 6). For example, the irst entry in Table II shows that a pumpable slurry stream comprising solid carbonaceous fuel (B) in admixture with water (C) may be passed through the retracted central conduit 15 of a single annulus pre-mix burner i.e.
Fig. 2 and 5 while simultaneously a stream of free-oxygen containing gas may be passed through annular passage 17.
Other modes of operation of the subject invention are possible in addition to those shown in Tables II and III.
With respect to the operation of a double annulus embodiment of the subject burner, the second entry of Table III shows that free-oxygen containing gas (A) may be passed through both annular passages. In such case, any member of the following group may be simultaneously passed through one or both annular passages 17 and 51: air, oxygen-enriched air, and substantially pure oxygen. Also, as shown in the seventh entry in Table III, free-oxygen containing gas (A) in admixture with steam (D) (say up to 25 vol. % of the total amount of H20) may be passed through the central . .

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- ~3 -conduit 15 and the remainder of the H20 as ~ater (C) may be passed through the intermediate annulus 17 as part of the liquid carrier for the slurry.
When the liquid carrier for the slurry of solid carbon-aceous fuel is a liquid hydrocarbonaceous material premature combustion within the burner may be avoided by one or more of the following:
(1) keeping the fuel below its autoignition temperature, (2) including water in the solid fuel slurry,

(3) using air or air enriched with oxygen i.e. up to about 40 vol~ % 2'

(4) mixing steam with the air, (S) employing a double annulus pre,mix burner (Fig. 6) in which the tip of the intermediate exit nozzle has about 0 retraction from the face of the burner. In such case, the free-oxygen containing gas such as substantially pure oxygen may be separately passed through the outer annular passage of the burner and into the reaction zone of the gas generator where it reacts by partial oxidation with the multiphase mixture discharged from the pre-mix zone of the burner, and (6~ discharging the multiphase mixture at the exit orifice at the tip of the burner with a discharge velocity which ls greater than the flame propagation velocity.

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TABLE I
Material Symbol Free-Oxygen Containing Gas A
Solid Carbonaceous Fuel B
Water C
Steam D
Liquid Hydrocarbonaceous Material E
Temperature Moderating Gas F

TABLE II
SINGLE ANNULUS PRE-MIX BURNER (See Figures 2 and 5) Çentral Conduit 15 Annulus 17 B + C A
B + C + E A
B + E A + D
A . B + C
A B + C + E
A +.D ~ B + E

TABLE III
DOUBLE ANNULUS PRE-MIX BURNER (See Figure 6) Intermediate Outer Central Conduit 15 Annulus 17 Annulus 51 A B + C A
B + C A A
B + C A F
A B + C + E A
A - B + C + E A + D
D . B + C + E A
A + D B + C + E A
B + C ~ E A
B + C + E - D A
B + C + E A D
A . B + E A + D
A + D B + E A
A + D B + E A + D
D B + E A
A B + E D
B + E A + D A + D
B + E A A + D
B + E D - A
B + E A D
A B ~ E F
B + C A E
A B ~ C E
E : B + C A
B + C E . A
. . ~

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Other embodiments of the invention can in addition avoid the following problems which can occur during use.
During operation of a partial oxidation gas generator, it may be necessary to rapidly turndown the production of the effluent gas to about l/8 to 3/4 of the plant-design output, without replacing the burner. Changing the burner requires - a costly shut-down period with resultant delay. Thus, in combined cycle operation for power generation a durable burner is required which offers minimum pressure drop and with which throughput levels may be rapidly changed - up and down - without sacrificing stable operation and efficiency.
Further, the burner should operate with a variety of liquid, solid, and gaseous fuels, and mixtures thereof. These requirements have been fulfilled with the subject burner.
These problems and others may be avoided by an embodi-ment of the invention comprising: a cer.tral conduit, ~aid central conduit being cIosed at the upstream end and having an unobstructed downstream circular exit orifice at the tip of the burner; an outer conduit coaxial and concentric with said central conduit along its length and in spaced relation-ship therewith and forming an annular passage therebetween, said annular passage being closed at the upstream end and having an unobstructed downstream annular exit orifice at ; the tip of the burner; a central bunch of tubes in symmet-rical spaced relationship passing through the closed end of said central conduit and making a gastight seal therewith, the tubes of said central bunch of tubes being parallel to each other and to the burner axis and extending along said ,~ .
central conduit without touching each other and having upstream inlet means for introducing a first feedstream and downstream ends through which said first feedstream is dis-charged, means for spacing and supporting said central bunch of tubes with respect to the inside wall of said central conduit and to each other, and upstream inlet means~for introducing a second feedstream into said central conduit and the interstices between the central bunch of parallel tubes;
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an annular bunch of tubes in symmetrical spaced relation-ship passing through the closed end of said annular passage and making a gastight seal therewith, the tubes in said annular bunch of tubes being parallel to each other and to the burr.er axis and extending along said annular passage without touching each other and having upstream inlet means for introducing a third feedstream into said tubes and down-stream ends through which said third feedstream is discharged, and wherein the do~nstream ends of said annular bunch of tubes are retracted upstream from the burner face a distance of about 0 to 12 times the minimum width of the annular exit orifice at the tip of the burner, means for spacing and supporting said annuIar bunch of tubes with respect to the inside wall of said annular passage and to each other, and upstream inlet means for introducing a fourth feedstream intD
said annular passage and the interstices between the annular bunch of parallel tubes in said annular passage.
By means of these embodiments a large volume of the first reactant stream is split into a plurality of separate streams of reactant fluid flowing through the central bunch of parallel tubes. This permits the introduction of the second s*ream of reactants passing concurrently through the central conduit into the interstices surrounding the central bunch of tubes. Similarly, a large volume of the third reactant stream is split into a plurality of separate streams of reactant f-luid flowing through the annular bunch of parallel tubes. The fourth stream of reactants passing con-currently through the annular passage is introduced into the interstices surrounding the annular bunch of tubes. The greater the number of tubes in a bunch, the better the distri-bution of one reactant within the other reactant. The mixing of the reactant streams whish takes place downstream of the ends of the tubes is facilitated by this improved distribution.
Such efficient mixing of the feedstream facilitates a more uniform partial oxidation of the fuel to prod~ce H2 and C0.
The combustion efficiency of the process is thus increased.

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Furthermore the above stated problems may be avoided by a further embodiment of the invention constituted hy a swirl burner which is contructed in the following manner. A first cylindrical conduit is closed at the upstream end and has an unobstructed circular exit orifice at the downstream tip of the burner. A central bundle of open-ended helical tubes, extends longitudinally down said first conduit. The upstream inlet portion of each individual helical coil in said central bundle of helical tubes preferably passes perpendicularly through a tube-sheet located below the closed end of said first conduit and makes a gastight seal therewith. The upstream open ends of the central bundle of helical tubes are in communication with a chamber, such as a cylindrical - 18 - 116~0~
manifold, through which a first feed stre~m is introduced.
By th~s means said first reactant feed stream may be spllt into a plurality of separate streams which pass down through the separate helical tubes in said central bundle and then discharge as a plurality of swirling streams.
The separate helical coils in the central bundle of helical tubes are supported and op~ionally spaced within the first conduit and with respect to each other by means of conventional supports and spacers. By this means a plurality of related free-flow helical-shaped passages may be formed in the cylindrical space occuDied by ~he central bundle of helical tubes. A second feed stream is introduced near the upstream end Or said first conduit, splits into separate streams upon p2ssing down through said helical passages or into the interstices between the helical tubes, and then discharges as a plurality of swirling or ~urbulent streams.
The plurality of first and second feed streams impinge elther downstream from the face of the burner or in a ~ ~ pre-mix zone upstream from the face of the burner where ; 20 intimate;mixing and atomization takes place.
The central bundle of helical tubes is coaxial with the ce~ntral longitudinal axis of the burner and preferably comprises at least one and~with larger burners a plurality of equaIly spaced concentric rings o~ multiple helices with a common axis occupying a cylindrical space.
Preferably, the inlets and outlets of the plurality of helical coils in the central bundle are located at the intersections of at least one and preferab~y a plurality of evenly spaced radial rows and said concentric ring or rings.
~ ~ 30 The sides of the individual helical coils in adJacent ; concentric rings may or may not touch. ~Yhen they touch, 19 - ~ 1620~
at least a port~on of the second reactant feed stream may flow through said plurality of helical passages formed within said first conduit by tne screw-shaped outside surfaces of said central bundle of helical tubes. By separating the helical coils in ad~acent rings, more of the second feed stream may be made to flow into the interstices between the helical coils in said central bundle. Thorough mixing together of the first and second feed streams is provided by either one or both of these schemes. Further, atomization may take place.
In another embodiment, the previously described swirl burner has a high-turn-down capability. In this embodiment .a second coaxial cylindrical conduit ls radially spaced from and surrounds said first coaxial cylindrical conduit along its length. An annular space is thereby provided between said first and second coaxial conduits.
The annular space is closed at the upstream end and has an unobstructed downstream annular exit orifice at the tip of the burner.
2~ An annular bundle of open-ended helical tubes comprising a plurality of concentric helical coils with a common axis occupies said annular space. The upstream inlet portion of each individual helical coil in said bundle of annular helical tubes preferably passes perpendicularly through an annular tube-sheet located below the closed end of said annul æ~space and makes a gastight seal therewith.
The upstream open ends of the annular bundle of helical ; tubes are in communication with a chamber, such as an annular manifold t~ough which a third feed stream is 3o introduced. By this means said third L eed stream may be - 20 - 91620~6 split into a plurality of separate st~e~ms whlch pass down through the separate heIical tubes in said annular bundle and discharge as a plurality of swirling streams.
The separate ~elical coils in the annular bundle of helical tubes are supported and optionally spaced within said annular space and ~ith respect to each other by means of conventional supports and spacers. ~y this means a plurality of related helical-shaped passages may be formed in the annular space which is occupied by the annular bundle of helical tubes. A fourth feed stream is introduced near the closed upstream end of said second condult, splits into separate streams upon passing down through sai~d helical passages or lnio the interstices between the helical tubes, and discharges as a plurality of swirling or turbulent streams~. The plurality of third and fourth swirling feed streams impinge together and intimately mix. Further, atomization may take place.
The annular bundle of helical tubes is coaxlal - with the central longltudlnal axis o~ the burner and preferably comprises at least one and preferably a plurality of equally spaced concentric rings of multiple helices with a~common axis occupying~said annular space. Preferably, the inlets and outlets of helical co1ls in the annular bunale are located at the inte~sections of said evenly spaced radial row or rows and said evenly spaced concentric ring or rings. In the manner discussed previously in connection with the central bundle of helical tuhes the sides of individual helical coils in adjacent concentric rings may or may not touch. ~Jhen they touch, said plurality of helical passages are formed within said annular space by the .

:

1 ~20~

screw-shaped outside surfaces of said annular bundle of helical tubes. By separating the helical coils in adjacent rings, more of the fourth feedstream may be rnade to flow into the interstices between the helical coils in said annular bundle.
In either of the above described embodiments where a central bundle of parallel or helical tubes and an annular bundle of parallel or helical tubes are provided, said first and third feedstreams and said second and fourth feedstreams, preferably, are respectively split streams from a fuel stream and a gaseous oxidant stream. In one embodiment, however, the first and fourth feedstreams, and the second and third feedstreams are respectively split streams from a fuel stream and a stream of gaseous oxidant. Flow control means may be provided in these embodiments for controlling the introduction of said four feedstreams into the burner. sriefly, a manual or automatically controlled fluid-controller is placed in each feed line. For slurry fuel and some viscous liquids e.g.
resid feed lines, a signal from the controller is trans-mitted to a speed control for a positive displacement pump.
For most liquid or gaseous hydrocarbon fuel feed lines and for oxidant feed lines, the signal from the controller is transmitted to a flow control valve. Responsive to said signal, the speed of said pump is varied, or alternately the opening in said flow control valve is changed. By this means, the ratio for the streams of fuel and/or oxidant passing through the burner may be adjusted up or down, say up to about 50% of the Design Conditions. Alternatively, a flow control valve may be inserted in each of the four feed streams to start or stop the flow of the feed streams to the central conduit and/or the annular passage and to their re-spective bundles of tubes. By this means, three ranges of flow through the burner may be obtained. Further, both of these flow control schemes may be combined to vary the flow rate of each feed stream from 1/8 to 3/4 of maximum.
In the embodiments utilizing helical tubes, the central bundle of hel~cal tubes may number in the range of about 1-200 ~: :

I lB2~

or more, such as about 2-180, say about ~-48 helical coils.
The annular bundle of helical tubes may number in the range of about 1-600 or more, such as about 2-580, say about 8-96 helical coils. There may be 1 to 7 or more concentric circular rings of helical tubes in the central and/or annular bundles. All of the helical coils in either the central, annular, or both bundles of helical tubes are t~listed in the same direction i.e. clockwise or counterclockwise. ~lowever in one embodiment, all of the helical coils in the central bundle of helical tubes are twisted in one direction i.e.
either clockwise or counterclockwise, and all of the helical coils in the annular bundle of helical tubes are twisted in the opposite direction.
In general for large-sized burners, the greater the number of tubes in a bunch, the better the distribution of one reactant within the other reactant. The mixing of the reactant strear,lswhich takes place downstream of the ends of the tubes is facilitated by this improved distribution. Such efficient mixing of the feedstreams facilitates a more uniform partial oxidation of the fuel to produce H2 and C0. The combustion efficiency of the process is thus increased. In one embodiment for a small sized burner, the central and/or annular bundles of helical tubes are replaced by a single central helical coil and/or a single annular helical coil.
By means of the subject invention, the reactant streams impinge and are intimately mixed together to produce a swirling mixture which is reacted by partial oxidation in the reaction zone of the gas generator. The reactions are made to proceed in local regionq where there is less opportunity for overheating the fuel with an insufficient supply of oxygen to result in the formation of soot. Thus, the amount of unconverted particulate carbon produced for a given oxygen ~to carbon atomic ratio in the feed may be substantially reduced. Further, "overburning" of the fuel to produce carbon dioxi e is substantially reduced. It is recommended that the subject burner be made from heat and corrosion-resistant metal , ::

alloys.
The velocity of the reactant stream through the central and annular bunches of tubes, whether ~arallel or helical, or alternatively through the central conduit or annular passage surrounding said tubes is in the range of about 5-100, say 10-50 feet per second at the face of the burner when said reactant stream is a liquid hydrocarbon fuel or liquid slurry of solid carbonaceous fuel, and in the range of about 150 feet per second to sonic velocity, say 200-5(~0 feet per second when said reactant stream is a gaseous hydrocarbon fuel or a free-oxygen containing gas with or without admixture with a temp-erature moderator.
The central bunch of tubes, in the embodiments utilizing parallel tubes, may number in the range of about 2-200 or more, say about 6-36. The annular bunch of such tubes may number in the range of about 4-600, or more, say about 12-108.
There may be 1 to 7 or more concentric rings of tubes in eah bunch.
The ratio of the total tube cross-sectional area (basis inside diameter) for the annular bunch of tubes (TA)(whether parallel tubes or helical tubes) to the total tube cross-sectional area (basis inside diameter) for the central bunch of such tubes (Tc~ may be in the range of about 2-8. Simi-Iarly,the ratio of the annular interstitial cross-sectional area (IA) surrounding the annular bunch of tubes to the central interstitial cross-sectional area (Ic) surrounding the central bunch of tubes may be in the range of about 2-8~
The inside diameter of the parallel tubes in either bunch may range from about 1/16 to 2 inches in diameter. The length of the tubes in the central and annular bunches and their spacing are such as to permit the external reactant stream to flow evenly into the interstices between the tubes.
For example, the length of the tubes in either tube bundle may range from about 1/2 to 24 inches or longer and preferably from about 4 to 10 inches, with greater lengths required as the number of tubes and the total size of-the burner increases.
Preferably, the ratio of the length to inside diameter of the l 16~6 tubes should be at least 8. Preferably, the inside diameter and the length of each tube should be the same for all tubes in the central bunch or the annular bunch. By this means equal flow may be obtained through all of the tubes.
The inside diameter of the helical tubes in the central and/or annular bundles may range from about 1~16 to 2 inches, or more. The height, spacing, and pitch of the individual coils in the central and annular helical bundles of tubes are such as to lmpart the desired swirl to the related feed-streams and/or to permit the external reactant stream to flow evenly into the interstices between the tubes. For example, the overall height of~the coils in either tube bundle may range from about 1 to 36, such as 4 to 12 inches or more.
Greater heights may be required as the number of tubes and the to-tal size of the burner increases. Preferably, the inside diameter of each tube should be the same for all tubes in the central and/or annular bundles. By this means equal flow may be obtained through all of the tubes.
Alighnment pins, fins, centering vanes, spacers and other conventional means are used to symmetrically space the tubes and conduits with respect to each other and to hold same in stable alignment without obstructing the free-flow of the feedstreams in the central and annular interstitial zones.
The downstream exit ends of the plurality of annular and central bunches of tubes (parallel or helical) preferably are circular in cross-section and terminate in the same plane perpendicular to the longitudinal central axis of thè burner.
The ends of the central, and, in some embodiments, of the ~annular, bunch of tubes are retracted upstream from the burner ~ace to provide substantial mixinq of t~e reactants and volatilization of the slurry medium prior to discharge.
The central conduit exit orifice and/or the annular exi~
orifice may have converging sections. For example, the central conduit exit orifice may comprise a frusto-conical rear portion having a converging angle in the range of about ; ~ ~,,, : :

~ 16~04~

15 to 90 from the central longitudinal axis of the burner.
The rear portion may develop into a normal cylindrical, or a diverging frusto-conical (e.g. at a half angle of about 15 to 90 ), front portion which terminates at the dowmstream face of the burner. The cylindrical front portion may have a height in the range of about 0 to 1.5 times its own diameter.
Similarly, said annular exit orifice may comprise a generated converging frusto-conical shaped annular rear portion having a converging angle in the range of about 15 to 90 from the central axis of the frusto-conical section, said central axis being parallel to the central longitudinal axis of the burner.
The rear portion may develop into a generated normal cylind-rical, or a divering frusto-conical (e.g. at a half angle of about 15 to 90), annular front portion which terminates at the downstream face of the burner. The cylindrical front portion may have a height in the range of about 0 to 1.5 times its own width.
In one embodiment, the central conduit exit orifice and/or the annular exit orifice are in the shape of or is generated by an American Society of Mechanical Engineer's standard long-radius nozzle. A further description of said nozzle may be found in "Thermodynamics Fluid Flow and Heat Transmission" by Huber 0. Croft, page 155, First Editlon, 1938 McGraw-Hill Book Company.
The burner may be cooled on the outside by means of cooling coils that encircle the outside barrel of the burner along its length. The downstream end of the burner may be provided with a cored face plate through which a coolant is circulated. For example, an annular cooling chamber may encircle the annular exit orifice and/or the central conduit exit orifice. The cooling chamber, central conduit exit orifice and/or the annular exit orifice may constitute a single piece of thermal and wear resistant material such as tungsten carbide or silicon carbide. Any suitable coolant m~y be employed e.g. waterO

' ~ 1620~

In one embodiment of the subject burner, a plurality of high pressure high velocity jet streams of a gaseous material is passed into the central conduit and/or annular passage at various locations along their length. By this means atom-i~ing of the fuel feedstream and, optionally, mixing it withthe oxidant stream may be facilitated. For example, the gaseous material may be passed through a plurality of small diameter passages or holes i.e. about .032 to .50 diameter that lead into said central conduit and/or annular passage.
The gaseous material may be selected from the group con-sisting of steam, free-oxygen containing-ga~ C02, N2, fuel gas, a recycle portion of the product gas, and mixtures thereof. The gaseous material may be introduced into the burner at a temperature in the range of about ambient to 1500F and a velocity in the range of about 100 feet per second to sonic velocity. The pressure of the gaseous mater-ial may be in the range of about 76 to 4500 psia and is greater than the pressure of the other feedstreams passing through the burner.
The discharge velocity for the material leaving through the central exit orifice is in the range of about 0.5 to 1.5 times, and preferably the same as, the discharge velocity of the material leaving through the annular exit orifice. The streams leaving the two exit orifices mix together and atom-ization may take place immediately downstream from the face of the burner.
In another embodiment of the invention, additional mix~
ing of the reactant streams is effected in at least one, say 2 to 5 coaxial cylindrical shaped pre-mix chambers in series in the central conduit and/or at least one, sa~ 2 to 5 annular shaped pre-mix chambers in series in the annular passage ~hen provided. In such case, the downstream ends of the central bunch of tubes are retracted upstream from the face of the burner a distance of 2 or more, e.~. about 3 to 10, times the minimum diameter of the circular exit orifice and/or the down-stream ends of the anrular bunch of tubes are retracted ) 16~
_ 27 -upstr~am from the face of the burner a distance of 0 to 12, such as 2 or more, say about 3 to 10, times the minimum width of the annular exit orifice. Preferably, the down-stream ends of the central and annular bunches of tubes are retracted upstream from the entrance to the first pre-mix chamber in the line. For example, the set back of the ends of the tubes from the entrance to the first pre-mix chamber may be in the range of about 0.1 - 2.0 times the diameter of the first pre-mix chamber.
In one embodiment, each of the pre-mix chambers in the central conduit except the first are cylindrical shaped and comprises a coaxial cylindrical body portion ~ollowed by a coaxial at least partially converging outlet portion. The first cylindrical shaped pre-mix chamber in the central con-duit comprises a normal coaxial cylindrical body portion that discharges directly into the next in line coaxial cylindrical shaped pre-mix chamber. Each pre-mix chamber in the annular conduit except the first is annular shaped and comprises a coaxial generate~-normal cylindrical annular body portion followed by a coaxial generated converging frusto-conical shaped annular outlet portion. The first annular shaped pre-mix chamber comprises a coaxial generated normal cylindrical annular body portion that discharges directly into the next in line coaxial annular shaped pre-mix chamber. The con-verging outlet portions of said pre-mix chambers may be made from tungsten carbide or silicon carbide for increased wear resistance.
The size relationship between successive pre-mix chambers in the subject burners may be expressed in the following 3~ manner: For burners in which the pre-mix chambers in the central conduit are successively numbers 1 to 5 and/or the pre-mix chambers in the annular passage are numbered 6-10, then the ratio of the diameter of any one of said central chambers to the diameter of the next central chamber in the line i.e.
Dl:D~; D2:D3; D3:D4; or D4:D5 may be in the range of about 0.2-1.2. The ratio of the length of any one central pre-mix ~ ~6204~

chamber in said central conduit to the length of the next central pre-mix chamber in the line i.e. L1:L2; L2:L3;
L3:L4; or L4:L5 may be in the range of about 0.1-1Ø The ratio of the annular width of any one of said annular pre-mix ch~mbers to the width of the next annular chamber in the line 6 7; 7 B; W8:W9; or Wg:W10 may be in the range of about 0.1-1.2. The ratio of the length of any one annular pre-mix chamber in said annular passage to the length of the next annular pre-mix chamber in the line, i.e. L6:L7; L7:L8;
L8:Lg; or L9:Llo may be in the range of about 0.1-1Ø
In most other respec~ the design of this pre-mix embodi-ment of the buxner, including the tubes, passages, orificesr water-cooled face-plate and cooling coils, high pressure high velocity jets of a gaseous material entering said central and/or annular pre-mix chambers, and flow control means are substantially the same as previously described. Further, the temperature, pressure and velocity ranges for the streams of materials passing through the various passages of the burner are substantially the same as those discussed previously.
In the operation of the embodiment of the burner employ-ing pre-mix chambers flow control means may be used to control the flow of the four feedstreams to the tubes and passages in the burner in the same manner as described pxeviously. The feedstreams entering the burner and simultaneously and con-currently passing through at different velocities impinge and mix with each other in the first pre-mix chambers. The impingement of one reactant stream, such as the liquid slurry of solid carbonaceous fuel in a liquid medium optionally in admixture with a temperature moderator, with another reactant stream, such as a gaseous stream of free-oxygen containing gas optionally in admixture with a tempera*ure moderator at a higher velocity, causes the liquid slurry to break up into a fine spray. The multiphase mixture produced then successiv~ly passes through any remaining pre-mix chambers where additional mixing takes place. As the mixture passes frPely through the subject unobstructed burner its velocity changes many times.

~ ~62~

For example, at various points in the burner the velocity of the mixture may range from about 20 to 600 ft. per sec. As the mixture flows from one pre-mix chamber to the next, the velocity changes are mainly the result of changes in the diameter of the flow path and the quantity and temperature of the mixture. This promotes a thorough mixing of the com-ponents as well as swirling which takes place when helical tubes are used. By operating in the region of turbulent flow, mixing may be ~ ~620~
maximized. Further, direct heat exchange between the materials takes place within the burner. From 0-100 vol. %, say about

5-25 vol. % of the liquids in the feedstreams may be vapor-ized before the feedstreams leave the burner. By means of converging exit orifices, the feedstreams may be accelerated directly into the reaction zone of the partial oxidation gasifier.
Burning of the combustible materials while passing through the pre-mix 7one of the burner may be prevented by discharging the multiphase mixtures at the central and annular exit orifices at the tip of the burner with a dis-charge velocity which is greater than the flame propagation velocity. Flame speeds are a function of such factors as composition of the mixture, temperature and pressure. They may be calcaluted by conventional methods or determined experimentally. The ratio of the discharge velocity for the .
muItiphase mixture being discharged through the central exit orifice to the multiphase mixture being discharged through the annular exit orifice may be in the range of about 0.5 to 1.5, such as 1.0 Depending on such faators as the temperature, ~ .
velocity, dwell time and composition of the feedstreams; the deslred amount o~ vaporization of liquid carrier; the tempera-~ ture and amount of recycle gases in the generator; and the ; ~ desired life of the burner; cooling coils may or may not encircle the outside barrel of the burner along its length.
For similar reasons, the burner may or may not be provided with an annular shaped cooling chamber at the downstream end.

The multiphase mixtures simultaneously departing - from the central orifice and~or the annular orifice at the :
: . ' - 31 ~ 0~
downstream tip of the burner mix together downstream from the face of the burner.
Advantageously, by means of the subject burner, the exothermic partial oxidation reactions take place a sufficient distance downs~ream from the burner face so as to protect the burner from thermal damage.
Liquid hydrocarbon fuels and/or pumpable slurries of solid carbonaceous fuels having a dry solids content in the range of about 30 to 75 wt. %, say about 40 to iO wt. %
may be passed through the inlet passages of the subject burner. For example, the fuel streams may be passed througn the central and/or annular bunch of tubes. The inlet temp-; eratu~e of the liquid hydrocarbon fuel or the slurry is in the range of about ambient to 500 F., but preferably below the vaporization temperature of the liquid hydrocarbon at ; the given inlet pressure in the range of about I to 300 atmospheres, such as 5 to 250 atmospheres, say about 10 to lO0 atmoshperes.
The term solid carbonaceous fuels, as used herein 2C to describe suitable solid carbonaceous feedstocks, is intended to include various materials and mixtures thereof from the group consisting of coal, coke from coal, char from coal, coal liquefaction residues, petroleum coke, parti-culate carbon soot, and solids derived from oil shale, tar sands, and pitch. All types of coal may be used including anthracite, bituminous, sub-bituminous, and lignite. The particulate carbon may be that which is obtained as a by-product of the subject partial oxidation process, or that which is obtained by burning fossil fuels. The term solid carbonaceous fuel also includes by definition bits of garbage, dewatered sanitary sewage, and semi-solid organic .

- 32 _ ilB204~

materials such as asphalt, rubber and rubber-like materials including rubber automobile tires which may be ground or pul-verized to the aforesaid particle size. ~y suitable grind-ing system may be used to convert the solid carbonaceous fuels or mixtures thereof to the proper size.
The solid carbonaceous fuels are preferably ground to a particle size so that 100~ of the material passe~ through an ASTM E 11-70 Sieve Designation Standard 1.4 mm ~Alternative No. 14) and at least 80% passes through an ASTM E 11--70 Sieve Designation Standard 425 ~m (P.lternative No. 40).
The moisture content of the solid carbonaceous fuel particles is in the range of about 0 to 40 wt. ~, such as 2 to 20 wt. %. Predrying may be required if necessary in some instances to reach these levels.
The term free-oxygen containing gas, as used herein is intended to include air, oxygen-enriched air, i.e., greater than 21 mole % oxygen, and substantially pure oxygen, i.e., greater than 95 mole % oxygen, (the remainder comprising N2 and rare gases).
Simultaneously, a stream of free-oxygen containing gas is supplied to the reaction zone of the gas generator by way of a free passage in the burner, such as through the central ` conduit and/or annular pas.sage, when provided, at a tempera-ture in the range of about ambient to 1500F., and preferabIy in the range of about ambient to 300F., for oxygen-enriched air, and about 500 to 1200F., for air, and a pressure in the range of above about 1 to 300 atmospheres, such as 5 to 250 atmospheres, say 10 to 100 atmospheres. The atoms of free-oxygen plus atoms or organically combined oxygen in the solid carbonaceous fuel per atom of carbon in the solid 1 1620~
carbonaceous fuel (O/C atomic ratlo) may be in the range of 0 5 to 1.95. With free-oxygen containing gas in the reaction zone the broad range of said O/C atomic ratio may be about 0.5 to 1.7, such as about 0.7 to 1.4. More specifically, with air feed to the reaction zone, said O/C atomic ratio may be about 0.7 to 1.6, such as a~out 0.9 to 1.4O
The term temperature moderator as employed herein includes water, steam, CO2, N2, and a recycle portion of the product gas stream. The temperature moderator may be in admixture with the fuel stream and/or the oxidant stream.
For example in one embodiment, the ~eedstream comprises a slurry of liquid hydrocarbonaceous material and solid carbonaceous fuel. H2O in liguid phase may be mixed with the liquid hydrocarbonaceous carrier, for example as an ~emulsion. A portion of the H2O i.e., about 0 to 25 weight of the total amount of ~2 present may be introduced as steam in admixture with the free-oxygen containing gas. The weight ratio of ~20/fuel may be in the range of about 0 to 5, say about 0.1 to 3.
The term liquid carrier, as used herein as the suspending medium to produce pumpable slurries of solid carbonaceous fuels is intended to include various materials from the group consisting of water, liguid hydrocarbonaceous material, and mixtures thereof. However, water is the ~ preferred carrier for the particles of solid carbonaceous i fuel. ~n one embodiment, the liquid carrier is liquid carbon dioxide. In such case, the liquid slurry may - comprise 40-70 wt. ~ of solid carbonaceous fuel and the remainder is liguid CO2. The CO2-solid fuel slurry may be introduced into the burner at a temperature . ~ .

~ 34 ~ ~620~
in the range of about -67 F to 100 F depending on the pressure.
The term liquid hydrocarbonaceous material as used herein to describe suitable liquid carriers, is intended to include various materials, such as liquified petroleum gas, petroleum distillates and residues, gasoline, naphtha, kerosine, crude petroleum, asphalt, gas oil, residual oil, tar sand oil and shale oil, coal derived oil, aromatic hydrocarbon (such as benzene, toluene, xylene fractions), coal tar, cycle gas oil from fluid-catalytic-cracking operation, furfural extract of coker gas oil, methanol, ethanol and other alcohols and by-product oxygen containing liquid hydrocarbons from oxo or oxyl synthesis, and mixtures thereof.
The subject burners as shown in Figures 7 to 13 may ke operated with the feedstreams passing through alternate passages in the burner. Typical modes of operation are summarized in Tables I and II below.
Table I lists the materials being introduced into the gasifier by way of the burner and their corresponding symbol. The solid carbonaceous fuel ~B), water (C), and llquid hydrocarbonaceous material (E) may be mixed together in various combinations upstream ~rom the ~urner inlet to produce a pumpable slurry which may be introduced into the burner and then passed through one of the several free-flow passages of the burner as shown in Table II. For example, the first entry in Table II shows that a pumpable slurry stream comp~ising solid carbonaceous fuel (B) in admixture with water (C) may be passed through the central and/or annular bunch of tubes in the burner, i.e. Fig. 7 or lO or 11 or 13.
Whenever a fuel stream is lntroduced into the burner, a `

-- 35 ~ ~ 162046 corresponding stream of free~oxygen containing gas is simultaneously passed throuah th~ related central conduit and/or annular passage. Some additional examples follow:
(1) separate streams of free-oxygen containing gas are passed through said central and/or annular bunches of tubes;
and simultaneously separate corresponding streams of a pumpable slurry of solid carbonaceous fuel in a liquid carrier are passed through the related central conduit, and/or annular passage.
(2) separate streams of free-oxygen containing gas are passed through said central conduit and said annular pas-sage; while simultaneously a corresponding stream of liquid hydrocarbonaceous material is passed through the related central and/or annular bunches of tubes; and simultaneously a pumpable slurry of solid carbonaceous fuel in a liquid carriex is passed through the free bunch of said tubes, if any.
(3) separate streams of free-oxygen containing gas are passed through said central and/or annular bunches of tubes;

while simultaneously a corresponding stream of liquid hydrocarbonaceous material is passed through the related central conduit and/or annular passage; and simultaneously ;~ a pumpable slurry of solid carbonaceous fuel in a liquid carrier is passed through the free passage, if any.

.

- 36 - 11~2~
TAsLE I
Material Symbol Free-oxy.gen Containing Gas A
Solid Carbonaceous Fuel B
h'ater C
Steam D
Liquid Hydrocarbonaceous Material E
Temperature Moderating Gas F
Gaseous Hydrocarbon Fuel G

TABLE II

Central Central Annular Annular Conduit Bunch of Tubes Passage Bunch of Tubes A B+C A B+C
A+D B+C A+D B+C
B+~ A . B+C A
A B+C B+C A
B+C A A B+C
A B~C+E A B+C+E
B~C+E A~D ~ B~C+E A+D
A E A E
A+D B+E A+D B~E
B+E A+D B+E A~D
A+D E A B+C
E A E A
B+C A E A
. E . A B+C A
A . G A B+C
A . G A+D E
A E+F A E+F
E~F A+D E+F A~D

Other modes of operation of the subject invention are possible in addition to those shown in Table II.
For example, jet streams of a gaseous material may be simultaneously introduced into the central conduit and/or annular passage, as previousIy described.

When one of the fuel streams is a liguid hydro-carbon or the liquid carrier for the slurry of solid car-bonaceous fuel is a liquid hydrocarbonaceous material pre-mature combustion within the burner may be avoided by one ormore of the following:

, _ 3~ _ ~162~

(1~ keeping the fuel belo~ its autoignition temperature, (2) including water in the solid f~-el slurry, t3) using air or air enriched with oxygen i.e. up to about 40 vol. ~ 2' (4) mixlng steam with the air, (5~ employing about 0 retraction of the ends of the central and annular bunches of tubes from the face of the burner. In such case, the free-oxygen containing gas such as substantially pure oxygen may be separately discharged from the burner without first contacting the fuel stream.

(6) discharging the multiphase mixture at the central and ~nnular exit orifices at the tip of the burner with discharge velocities that exceed the flame propagation velocity.
The suhject burner assembly is inserted downward through a top inlet port of a compact unpacked free-flow noncatalytic refractory lined synthesis gas generator, for example as shown in our U.S. Patent No. 3,544,291.
The burner extends along the central longitudinal axis of the gas generator with the downstream end discharging directly into the reaction zone.
The relative proportions of the reactant feed-streams and optionally temperatuxe moderator that are intro-duced into the gas generator are carefully regulated to convert a substantial pvrtion of the carbon in the fuel e.g., up to about 90% or more by weight, to carbon oxides;
and to maintain an autogenous reaction zone temperature in the range of about 1700 to 3500F., preferably in the range of 2000to 2800F.
The dwell time in the reaction zone is in the range of about 1 to 10 seconds, and preferably in the range of about 2 to 8. With substantially pure oxygen feed to the gas generator, the composition of the effluent gas from the gas generator in mole % dry basis may be as follows:

- 38 ~ 2~
H2 10 to 60~ C0 20 to 60~ C02 5 to 40, CH4 D.01 to 5, H2S~COS
nil to 5, N2 nil to 5, and A nil to 1.5. ~Tith air feed to the gas generator, the composition of the generator effluent ~ gas in mole ~ dry basis may be about as rOllOws:
H2 2 to 30, C0 5 to 35, C02 5 to 25, CH4 nil to 2, H2S+COS
nil to 3, N2 45 to 80, and A 0.5 to 1.5. Unconverted carbon and ash are contained in the ef~luent gas stream.
The hot gaseous effluent stream ~rom the reaction zone o~ the synthesis gas generator is quickly cooled belo~

the reaction temperature to a temperature in the range of about 250 to 700F. by direct quenching in water, or by indirect heat exchange for example with water to produce steam in a gas cooler.
Advantageously, in another embodiment of the subject invention the subject burner may be used as the preheat burner during start-up of the gasifier, as well as the production burner. Start-up procedures are thereby simplified. Previously, time was lost when the gas preheat burner was replaced by the production burner, and the gasifler cooled down. Now the gasif1er may be brought up to operating temperature and held there by slmultaneously passing fuel gas through the central or annular bundle of tubes and air through the related central conduit or annular .
passage. Alternately, the fuel gas may be passed through the central conduit or annular passage in the burner and the air is passed through the related central or annular bundle of tubes. The fuel gas and air are mixed together to produce a well-distributed blend. Burning of the mixture by sub-; stantially complete combustion then takes place in the 3~ reaction zone Or the gas generator at an absolute ' _ 39 _ 1162~4~
pressure in the range o~ about o.56 to 300 atmospheres, and preferably at 1 atmosphere. The products o~ the complete combustion are removed from the reaction zone. For example, they ~.ay be vented to the atmosphere. By this means~ the reaction zone is heated to the temperature required ~or ignition Or the autothermal partial oxi~ation reaction of the principal fuel selected from the group consisting of a pumpable slurry of solid carbonaceous fuel, liquid or gaseous hydrocarbon fuel, and mixtures thereor with a free-oxygen containing gas and with or without a temperaturemoderator. For example, the autoignition temperature may be in the range of about 2000 to 270CF. At this point, the principal fuel, with or without admixture with a temperature moderator, is passed through either the central or annular bunch of tubes, or alternately the central conduit or annular passage, whichever is occupied by the fuel gas and air. Simultaneously a stream of free-oxygen containi~g gas, with or without admixture with a temperature moderator,!is passed through either the central conduit or annular passage of the burner, or alternately through either the central or annular bunch of tubes which ever is assoclated with the bunch of tubes or alternately with the conduit or passage through which the principal fuel is flowing.
' The stream of principal fuel and free-oxygen containing eas are mixed together to produce a well-distributed blend. The mixture ignites by autoignition and burns by partial oxidation downstream in the reaction zone of the free-flow noncatalytic gas generator at an autogenous temper-ature in the range of about 1~00 to 350C~ F., a pressure in ',1 .

0~

the range of about 1 to 300 atmospheres, an atomic ratio of oxygen carbon in the range of about 0.5 to 1 D 7 and H2O/fuel weight ratio in the range of about 0 to 5.0, such as 0.1 to 3.
At the moment t~lat the partial oxidation of the principal fuel commences, the fuel gas and related air supply may or may not be cut off. For e~ample, the fuel gas and related supply of oxidant may be continued at the same flow rate or at a reduced flow rate i.e. about 1/8 to 3/4 of the maximum flow rate. Further, if the supply of the fuel ~as to the burner is continued, then the flow rate of the fuel gas stream and the associated stream of oxidant is adjusted to provide an atomic O/C ratio in the range of D.5 to 1.7 and the partial oxidation of the fuel ga~ rather than complete combustion. Optionally, dep~nding on the desired composition of the product gas, the air may be replaced by another free-oxygen containing gas. For example, oxygen enriched air or substantially pure oxygen is preferred to make synthesis gas.
In another embodiment, the stream of fuel gas in the burner is replaced by an alternate fuel stream selected from the group consisting of a pumpable slurry of solid carbonaceous fuel in a liquid carrier i.e. water, hydrocarbon, oxygenated hydrocarbon, liguid or gaseous hydroc~rbon fuel, and mixtures thereof. Similarly, the air stream may be re-placed with a stream of free-oxygen containing gas other than air. The reactant streams are mixed together to produce a well-distributed blend in the proper proportions for reacting said alternate fuel by partial oxidation. After autoignition, 1 16~04B

said mixture is burned by partial oxidation downstream in the reaction zone of the gas generator simultaneously with the partial oxidation of the principal fuel and at the same operating conditions. The alternate fuel and the associated free-oxygen containing gas streams may be passed through the same or alternate passages in the burner as previously occupied respectively by the fuel gas stream and the associated air stream.
A raw stream of synthesis gas, fuel gas, or reducing gas (depending on the composition of the product gas) is produced and removed from the reaction zone. The hot ra gas stream may be then cooled, cleaned and purified by conventional methods.
In one embodiment, the aforesaid fuel gas in the preheat stage may be replaced by a liquid hydrocarbon fuel.
A free-oxyg-n containing ~as may be employed as the oxldant.

, ~ ~ ' ~ 162~4~

DESCRIPTION OF THE DRAWING
A more complete understanding of the invention may be had by reference to the accompanying schematic drawing which shows the subject invention in detail~ Although the drawing illustrates a preferred embodiment of the invention, it is not intended to limit the subject invention to the particular apparatus or materials described. Corresponding parts in the several figures have the same reference numbers.
Referring to FIG. 1, the burner assembly for a retrac-ted central conduit pre-mix burner having a single annulus and one pre-mix chamber is indicated generally as 1. Face-cooling chamber 2 is located at the downstream tip of the burner. Circulating cooling water enters by way of inlet pipe 3. The cooling water departs by way of coils 4 that encircle the outside diameter of the burner along its length and through outlet pipe 5. By means of cooling chamber 2 and cooling coils 4, burner 1 may be protected from thermal damage. Face 6 is at the outermost downstream tip of burner 1. Burner 1 is installed do~nwardly through a port in the top of a free-flow partial oxidation synthesis gas generator (not shown). The longitudinal central axis of burner 1 is preferably aligned along the central axis of the synthesis gas generator by : , .

2 04 ~

means of mounting flange 7. Reactant streams pass into the burner by way of inlets 8 and 9.
In FIG. 2, the downstream end of burner 1 is shown in cross-section. This view is taken between A-A of FIG. 1 and comprises unobstructed inner coaxial retracted central conduit 15 and outer concentric coaxial conduit 16 which is disposed longitudinally about inner central conduit 15.
Spacing means 18 provide a free-flow annular passage 17 between the outside diameter of central cylindrical conduit 15 and the inside diameter of outer cylindrical conduit 16 Exit orifice 20 at the downstream tip of central conduit lS~
is preferably straight, circular in cross-section, and perpendicular to the longitudinal axis of the burner.
Alternately, exit orifice 20 may be converging or diverging.
Outer conduit 16 terminates at the downstream end of the burner with converging nozzle 21. A vertical cross section of exit orifice 21 may be frusto-conically shaped, which may or may not merge into a~right cylinder. Preferably for wear resistance, as shown in Fig. 2, nozzle 21 comprises a frusto-conical rear portion 22 that develops into a right cylin-- drical front portion 23 which terminates at the downstream face 6 of the burner. The cylindrical exit section will permit: (1) additional burner life because of increased surface available for abrasion, and (2) fabrication of a ceramic or refractory insert or an entire cooling chamber from a .hermal and abrasion resistant material i.e., tungsten or silicon carbide in order to reduce damage and to extend burner life.

~' ~ ~6~04~

The height of the front cylindrical portion 23 of exit no7-zle 21 is in the range of about 0 to 1.5, say about 0.1 to 1.0 times, its own diameter i.e. the minimum diameter of converging nozzle 21. The diameter of exit orifice 20 of central conduit 15 is in the range of about 0.2 to 1.5, say about 0.5 to 0.8 times the minimum diameter of con-- verging nozzle 21.
The downstream end of the burner may or may not be cooled. Preferably, as shown in Figs. 2,4,5 and 6, coaxial annular shaped cooling chamber 2 surrounds exit orifice 21 at the burner tip. By passing water through cored section ; 24 of cooling chamber 2, the tip of burner 1 may be pre-vented from overheating. Optionally for simiIar reasons, outer conduit 16 may be kept cool by passing water through coils 4. Suitable converglng angles for orifice 21 are in the range from about 15 to 90 from the central longi-tudinal axis of the burner. The downstream tip of exit orifice 20 of central conduit 15 is severely retracted upstream from face 6 of burner 1 a distance of two or more times the minimum diameter of converging exit nozzle 21.
For example, the setback of tip 20 of central conduit 15 from burner face 6 may be in the range of about 3 to 10 times ;~ the minimum diameter of converging exit nozzle 21. The space between tip 20 of central conduit 15 and burner face 6 constitutes the unobstructed pre-mix zone 25.
In the operation of burner 1, either reactant stream i.e. see Table II supra, may enter burner 1 by way of inlet 9 of Fig. 1 and pass directly from the upstream portion down through free-flow central condui, 15, through 0 ~ ~ ' - 4~ _ exit orifice 20, and into pre-mix zone 25, as shown in Fig.
2. Simultaneously and concurrently, the other reactant stream may enter burner 1 by way of inlet 8 of Fig. 1 and pass directly from the upstream portion 30 of outer conduit 16 down through free-flow annular passaye 17 and into pre-mix zone 25 where intimate mixing of the two reactant streams takes place. Further, direct heat exchange between the two reactant streams takes place in pre-mix zone ~5. The temperature in the pre-mix zone is controlled so that a controlled amount of the liquid carrier may be vaporized without burning i.e. from 0 to 100 vol. % say about 2 to 80 vol. %. Temperature control in the pre-mix zone may be effected by controlling such factors as dwell time and heat content of the entering streams, and amount of external cooling such as by coils 4, if any. Pre-mix zone 25 is substantially free from any obstruction to the free-flow of the materials pas~ing therethrough.
The velocity of the slurry of solid carbonaceous fuel in liqu.id carrier passing through exit orifice 20 of central conduit 15 or alternately exiting from annular passage 17 is in the range of about 0.5 to 75 f~. per sec, say about 2 to 20 ft. per sec., while the corresponding velocity for the free oxygen containing gas simultaneously passing through the other passage in the burner optionally i~ ad-mixture wIth steam, is in the range of about 85 feet per second to sonic velocity, say about 100 to 600 ft. per sec.
The slurry of solid carbonaceous fuel in liquid carrier enters the pre-mix zone in liqu;d phase at a temperature in the range of about ambient to 500F., and below the vapor-`~ 30 ization temperature of the liquid carrier, and at a pressure ~ .

2~4~

in the range cf about 76 to 4500 psia. While simultaneously, the free-oxygen containing gas stream, optionally in ad-mixture with steam, enters into the pre-mix zone at a temperature in the range of about ambient to 1200F., say about 100 to 600F., and at a pressure in the range of about 76 to 4500 psia. Intimate mixing and direct heat exchange takes place between the two reactant streams in the pre-mix zone. Volatilization of the liquid carrier in the pre-mix zone may amount to about 0 to 100 vol. %, say about 20 to 35 vol. % when the free-oxygen containing gas is introduced at a temperature in the range of about 300 o 600F~; or from about 70 to 100 vol. % when the free-oxygen containing gas is introduced as air preheated to a temperature in the range of about 1000 to 1200F. The multiphase mixture in the pre-mix zone is at a temperature below its autoignition temp-erature. The multiphase mixture lea~es burner 1 by way of exit orifice 21 at a discharge ~elocity in the range of about 75 to 600 ft. per sec., say about 150 to 350 ft. per sec., and above the flame propagation velocity and passes downwardly directly into the unobstructed reaction zone of the partial oxidation gas generator.
FIG. 3 is a vertical sectional view of another embodiment of the downstream end of outer conduit 16 as shown in Fig. 2. In Fig. 3, converging exit nozzle 21 is in the shape of an American Society of Mechanical Engineer's (A.S.M.E.) standard long-radius nozzle. It may or may not be cooled, such as by means of annular cooling chamber 2, in the manner shown in Fig. 2. A further description of said nozzle may be found in "Thermodynamics Fluid Flow and Heat ` 30 ~ransmission" by Huber O. Croft, page 155, First Edition, 1938 McGraw-Hill Book Company.

2 0~ 6 FIG. 4 is a vertical sectional view of ano'her embodiment of the downstream end of outer conduit 16 as shown in Fig. 2. In Fig. 4, exit nozzle 35 at the tip of the burner is made from a wear resistant material such as tungsten carbide or silicon carbide. Exit nozzle 35 com-prises a frusto-conical rear portion 22 which develops into a coaxial right cylindrical front portion 23. The frusto-conical outside diameter of exit orifice 35 is supported by coaxial .rusto-conical mating cavity 36 in annular cooling chamber 2. For example, exit orifice 35 made from tungsten carbide may be connected to the downstream tip of outer conduit 16 by joining the back surface 37 of cooling chamber 2 to the front surface of end flange 38 at the downstream end of outer conduit 16. ~Cooling water may be introduced into cored section 24 of cooling chamber 2 in the manner shown for inlet pipe 3 in Fig. 1. OptionaIly/ a cooling coil may encircle outer conduit 16 in the manner shown for coil 4 in Fig. 1. Hot high velocity slurries of solid fuel are abrasive. The life of the subject burner may be considerably extended by making exit nozzle 35 rom a wear reslstant material.
FIG. 5 is a vertical sectional view of the downstream end of another embodiment of the pre-mix burner shown in Figures 1 and 2~ Concurrent streams of different materials flowing through coaxial retracted central conduit 15 and simul-taneously through annular passage 17 are successively mixed together in pre-mix chambers 25 and 40. While the pre-mix zone in the embodiment in Fig. 5 is shown as comprising two ' 30 ' 1 1620il~

separate coaxial pre-mix chambers 25 and 40 in series, the pre-mix zone for other embodiments of the subject invention may actually comprise one or more, such as 2 to 5 coaxial pre-mix chambers. For example, as previously noted, the embodiment of the burner shown in Figures 1 and 2 have one pre-rnix chamber 25, while three pre-mix chambers 25, 40, and 41 are included in the embodiment of the burner shown in Fig. 6. Each pre-mix chamber in Figures 5 and 6, except for the first chamber in~the line, comprises a coaxial cylin-drical body portion 45 followed by a coaxial at least partially converging outlet portion 22 or 46 in Fig. 6 that may optionally develop into a straight cylindrical portion 49. Optionally, such outlets may be made from a thermal and wear resistant material i.e. silicon or tungsten carbide, such as described previously in connection with Fig. ~. In embodiments having a plurality of pre-mix chambers, the first pre-mix chamber in the line may have a straight coaxial çylindrical body portion 47, that discharges through circular orifice 39 directly into the next in line coaxial pre-mix chamber 40. Preferably, the mixture leaving one pre-mix chamber expands into the next successive pre-mix chamber. When the mixture is accelerated and expanded ~ ; through a final exit nozzle at the tip of the kurner into ; ~ the combustion chamber, a more stable and efficient com-bustion pattern results. The temperature, pressure and velocity ranges for the streams of materials passing through the various passages of the burner are substantially the same as those discussed previously. The inlet to the first pre-mix chamber 25 may have a converging inlet 48 as shown ,:

1 1~204~
- ~9 -in Fig. 5, or that shown in Fig. 2. One or more of the pre-mix chamber-~ may be a converging frusto-conical shaped section.
FIG. 6 is a vertical sectional view of the down-stream end of an embodiment of a retracted central conduit 15 pre-mix burner similar to burner 1, as shown in Fig. 1, but modified to provide two coaxial annular passages i.e.
intermediate annular passage 17 and outer annular passage 51. Further, the pre-mix zone comprises three successive free-flow coaxial pre-mix chambers 25, 40, and 41. By spacing means 18, concentric coaxial outer conduit 52, retracted coaxial intermediate conduit 53, and retracted coaxial centr~l conduit 15 may be radially spaced from each other to provide said separate annular passages and ~re-mix chambe~s with substantially no obstruction to the free-f~ow of materials therethrough. The downstream tip 20 of central conduit 15 is retracted upstream from fa¢e 6 of the burner a~
distance in the range of 2 or moxe, say 3 to 10 times the minimum diameter of converging exit orifice 21. The down-stream tlp 54 of intermediate conduit 53 lS retracted upstream from face 6 of the burner a distance in the range of 0 to 12, say 1 to 5 times the minimum diameter of con-verging exit orifice 21. Central conduit 15, and annular : :
passages 17 and 51 are respectively connected upstream to separate inlets, in a manner s~imilar to that shown in Fig.
1. The burner tip may be cooled by means of annular cooling chamber 2 which is coaxial with the central longitudinal axis of the burner at the downstream end in the manner shown. Alternately, cooling chamber 2 may be eIiminated.

l 16204~

In the operation of the embodiment of the burner shown in Fig. 6, the feedstreams simultaneously and con-currently passing through central conduit 15 and inter-mediate annular passage 17 at different velocities impinge and mix with each other in the first pre-mix chamber 25.
The impingement of one reactant stream, such as the liquid slurry of solid carbonaceous fuel in a liquid medium with another reactant stream, such as a gaseous stream of free-oxygen containing gas, steam, or temperature moderator at a higher velocity causes the liquid slurry to break up into a fine spray. The multiphase mixture then passes into the second pre-mix chamber 40 for additional mixing. Leaving chamber 40 by way of converging e~it nozzle ~6 and circular orifice 54 at the downstream tip of chamber 40, the multi-phase mixture passes into the third pre~mix chamber 41. The third feedstream enters the burner upstream through a separate inlet (not shown), and passes down outer annular passage 51~ When the set bac~ of orifice 54 at the tip of intermediate conduit 53 from face 6 of the burner is greater than 0, say in the range of about 1.0 to 5 times the minimum diameter~of exit orifice 21, then the third feed stream may mix with the first and second feed streams in pre-mix chamber 41 to produce a multiphase mixture. Further, in such embodiment, there may be 2 or more say 2 to 5 cylin-~drical coaxial pre-mix chambers in series. The multiphase mixture passes through converging nozzle 21 at the down-stream tip of the burner into the reaction zone of the gas generator.
' ' . , .

l 1 6 ~

In the embodiment of the burner with a setback of orifice 54 of about 0, then the third feedstream passing through outer annular passage will contact and mix with the multiphase mixture of the other two feedstreams from the pre-mix zone downstream from face 6 of the burner, say about l to 24 inches. Further, in such embodiment, there may be one or more say 2 to 5 cylindrical coaxial pre-mix chambers in series. For example, the stream of free-oxygen containing gas is passed through either the central or outer annular passage and the stream of liquid hydrocarbonaceous material is passed through the other passage i.e. the central conduit or outer annular passage whichever is free. SimultaneousIy, a slurry stream of solid carbonaceous fuel and water is passed through the intermediate passage. Alternately, the stream of free-oxygen containing gas is passed through either the intermediate or outer annular passage and thè
stream of liquid hydrocarbonaceous material is passed through the other passage i.e. the intermediate or outer annular passage whichever is free. Simultaneously, a slurry stream of solid carbonaceous fuel and water is passed through the central conduit. The temperature, pressure and velocity ranges for the streams of materials passing through the various passages of the burner are substantially the same as ~; those discussed previously. For example, see the discussion ; with respect to Fig. 2. The conditions for the liquid hydrocarbonaceous material are substantially the same as those given for the slurry of solid carbonaceous fuel. The feedstream flowing through the outer conduit of the burner mixes with the multiphase mixture of th~ other two feedstreams .

204~

from the pre-mix zone. ~owever, this mixing takes place dcwnstream from the face of the burner in the reaction zone of the free-flow partial oxidation gas generator~
Burning of the slurry while passing thxough the pre-mix zone of the burner may be prevented by discharging the multiphase mixture at the exit orifice at the tip of the burner with a discharge velocity which is greater than the flame propagation velocity. Flame speeds are a function of such factors as composition of the mixture, temperature and -pressure. They may be calculated by conventional methods or determined experimentally.
Advantageously, by means of the subject retracted central conduit pre-mix burner, the exothermic partial oxidation reactions take place a sufficient distance down-stream i~e. 6 inches to 2 feet from the burner face so as to ; ~ protect the burner from thermal damageO
~ As the mixture passes freely through the subject ; unobstructed burner its velocity changes many times. At various points in the burner the velocity of the mixture may range from about 20 to 600 ft. per sec. As the mixture fIows from one pre-mix chamber to the next, the velocity changes are mainIy the result of changes in the diameter of the flow path and the quantity and temperature of the mixture. This promotes a thorough mixing of the components.
Further, by operating in the region of turbulent flow, mixing may be maximized. Other burner design considerations such as size, length and number of chambers, and external -cooling may be calculated from such factors as quantity, ~ 162~

temperature and composition of the feedstreams, and desired amount of volatilization of the liquid carrier i.e. 0 to 100 vol. %.
The si~e relationship between successive pre-mix chambers in the subject burners may be expressed in the following manner: For burners having 1 to 5 pre-mix chambers successfully numbered 1 to 5 with chamber 5 being located closest to the downstream tip of the burner, the ratio of the diameter of any one of said chambers to the next chamber downstream in the line i.e. Dl~ D2; D2: D3;
D3: D4; or D4: D5 may be in the range of about 0.2-1.2.
Similarly, the ratio of the lengths of any one pre-mix chamber to the next downstream pre-mix chamber in the line, LI L2; L2 ~3; L3 L4; or L4: L5 may be in the range of about 0.1-1Ø
Advantageously, in one embodiment of the subject burner, as shown in Fig. 6 the material passing through outer annular passage 51 i.e. see Table III sup~a is heated by indirect heat exchange with the hot gaseous reaction products that recirculate in the reaction zone on the .
outside of the burner. By indirect and direct heat ex-.
change, the heated material in annular passage 51 may then heat the other reactant materials simultaneously and con-currently passing through the burner. In such case, all or a portion of the cooling coils 4 may be eliminated from the burner. Further, the reactants may be preheated and the liquid carrier may be vaporized from 0 to 100 vol. %.

.
:~ , ., .

- ~ 1620~
- 54 _ In still another embodiment of the subject burner shown in Fig. 6, a gaseous material is passed through outer annular conduit 51. At least a portion i.e. about S to 100 vol; % of the gaseous feedstream passing through annular conduit 51 is bled through a plurality of small diameter passages i.e. about .03~ to 0.50 inches diameter or holes of the same diameter, in a plurality of circumferential rings in the walls of intermediate conduit 53 at one or more locations 60-62 along its length. In such case, th~ down-stream outlet 56 of outer annular passage 51 may be com-pletely or partially blocked. For example, annular plate 57 i5 optionally shown in Fig. 6. Optionally, plate 57 may contain a plurality of small diameter holes 58 i.e. .060 to .75 inches diameter leading into pre-mix chamber 41. An-nular plate 57 may be placed perpendicular to the central longitudinal axis of the burner. By this means at least a portion of the third feedstream flowing in outer annular passage 51 may be pre-mixed with the materials simultaneously flowing through at least one or all of the following passages -20 in the burner at a Iower pressure; intermediate passage 17, and pre-mlx chambers 25, 40, and 41. For example, atomizing of the slurry of solid carbonaceous fuel and mixing it with the other feed streams may be facilitated by means of high-velocity, high pressure jet stream of a gaseous stream passlng through said passages at one or more locations 58 and 60-62. The gaseous material may be selected from the group consisting of ~team, free-oxygen containing gas, CO2, N2, a recycle portion of the product gas, and mixtures ; thereos. The gaseous material may be introduced into the - ~ .

I le204~

burner at a temperature in the range of about ambient to 1500F and a velocity in the range of about 100 feet per second to sonic velocity. The pressure of the gaseous material may be in the range of about 76 to 4500 psia and is greater than the pressure of the feedstreams passing through the central and intermediate passages.
In other embodiments, converging inlet 48 and the converging portion 22 of exit orifice 21 of the burners shown in Figures 5 and 6 and converging portion 46 in the burner shown in Figure 6 may be made from a wear resistant material such as tungsten carbide or silicon carbide. The wear resistant material may be shaped in the manner des-cribed in connection with the embodiments shown in Figures 3 and 4.
SPECIFIC EXAMPLE
The following is an example of the subject process and appar~tus employed in the partial oxidation of a slurry of coal and water with air; but the invention is not to be construed as limited thereto.

Fuel gas is produced in a vertical cylindrical refractory lined steel pressure vessel free from catalyst or any obstruction to the free-flow of materials therethrough.
The volume of the reaction zone is about 160 cubic feet.
The feedstreams are introduced into the reaction zone by way of a single annulus pre-mix burner having a retracted central conduit and two coaxial cylindrically shaped pre-mix chambers in tandem as shown in Fig. 5. The pre-mix burner is vertically mounted in a flanged port at I 1620d~

the top of the gas generator along the central longitudinal axis of the gas generator. Exit orifice 20 of the burner is retracted about 26 inches from the downstream face of the burner, and about 6 inches from circular exit orifice 39 at the end of the first pre-mix chamber 25. The length of the second pre-mix chamber 40 is 20 inches and the length of cylindrical portion 23 of exit nozzle 21 is 1.5 inches. The diameters of exit orifices 39 and 23 are 3.1 inches each.
The outside and inside diameters of central conduit 15 are respectively 1.315 and 1.049 inches. The inside diameter of passage 17 and the diameter of pre-mix chamber 40 are 4.563 inches each.
A slurry of bituminous coal and water having a solids content of 65 wt. % is prepared and passed through the center conduit 15 of the burner in liquid phase at a temperature of 100F, pressure of 600 psig~ and velocity of 10.4 feet per sec. The slurry comprises about 10,300 lbs. per hr of coal and 5~470 lbs. per hr of water. The coal is ground to a particle size so that 100% passes through an ASTM E 11-70 Sieve Designation Standard 1.4 mm and a* least 80% passes through an ASTM E 11-70 Sieve Designation Standard 425Jlm. The ultimate analysis of the coal in wt. % (moisture free basis) comprises: carbon 69.52; hydrogen 5.33; nitrogen 1.25; sulfur 3.86; oxygen 10.02; and ash 10.02.
Simultaneously, about 11.8 cubic feet per second of air comprising 21 mol ~ oxygen at a temperature of 1000F., pressure of 600 psig, and velocity of 113 feet per f ~ second are passed through the annular passage 17 of the ~ ' 30 1 1~20~5 burner. Mixing of the two feedstreams together takes place in pre-mix chamber 25. The mixture leaves through orifice 39 at a velocity of 271 feet per sec. and expands into pre-mix cha~ber 40 where intimate mixing of the components takes place. About 100 vol. % of the water in the slurry vaporizes in the burner and the mixture passes through pre-mix chamber 40 at a velocity of 125 ft. per sec. The multiphase mixture passes through exit nozzle 21 at the downstream tip of the burner at a temperature of 423~F and a velocity of 194 ft.
per sec. and directly enters the reaction zone of the partial oxidation gas generator.
Noncatalytic partial oxidation of the solid fuel takes place in the reaction zone at an autogenous temperature of 2800F and a pressure of 500 psig. About 23 million standard cubic feet per operating day of low BTU fuel gas are produced having the following'composition in mole %:
C0 17-1, H2 10-1, C02 6.7, H20 12.4, N2 52.6, A 0.6, H2S 0~5O
The heating value of the purified gas streams is a~out 110 BTU per SCF.
Advantageouslyl by employing the subject burner in place of a conventional burner, the specific oxygen consump-tion may be reduced 10% and problems of combustion instabil-ity are avoided.
Referring to FIG. 7, a high turndown burner assembly i5 depicted. Burner 111 is installed downwardly through a port in the top of a free-flow partial oxidation synthesis gas generator as shown in FIG. 9. The longitudinal central axis of burner 111 is preferably aligned along the central axis of the synthesis gas generator by means of a mounting flange. Burner 111 comprises central conduit 112, central bunch of parallel tubes 113 that pass longitudinally through central passage 114 of central conduit 112, co~xial concen-tric outer conduit 115, annular passage 116 between the outside diameter of central conduit 112 and the inside diam-eter of outer conduit 115 along its length and annular bunchof parallel tubes 117 that pass l.ongitudinally through annu-lar passage 116. Conduit 112 is a cylindrical wall that ~;
;

~ 1620~

separates central passage 114 and annular passage 116.
The downstream ends 118 of the central bunch of tubes 113, and, in some embodiments, also the downstream ends 119 of annular bunch of tubes 117 is/are retracted upstream from burner face 1110. Central circular orifice 1111 and annular orifice 1112 are determined by said imaginary plane perpen-dicular to the central axis of the burner at face 1110.
Central orifice 1111 has a diameter equal to the minimum inside diameter of central conduit 112 or nozzle if any at face 1110. The width of annular orifice 1112 is equal to the minimum inside diameter of outer conduit 115 or nozzle if any less the maximum outside diameter of central conduit 112 or nozzle if any at face 1110.
Wall brackets or tube spacers 1113 hold tubes 113 in a fixed parallel non-touching position with respect to each other and the inside wall of central conduit 112.
Central bunch of tubes 113 are passed through and sealed into disc shaped fixed tube sheet 1115. Tube sheet 1115 closes off the upstream end of central conduit 112.
Similarly, annular bunch of tubes 117 are pas.sed through and sealed into annular shaped fixed tube sheet 1116. Tube sheet 1116 closes off the upstream end of outer conduit 115 and annular passage 116. Conventional means i.e. welding, : turning, crimping, threading, rolling may be employed to provide a gas-tight seal or joint where the central and annular tubes penetrate the respective tube sheets. Mech-anical pressure fittings and coupling devices may be also employed.
The upstream ends 1117 of the central bunch of tubes 113 are connected to outlet means 1118 of central cylindrical shaped manifold 1119. Inlet feed pipe 1120 is connected to and in communication with manifold 1119. By this means, for example, a portion of a first reactant feedstream in feed pipe 1120 may be introduced into central manifold 1119, split into a plurality of streams which pass through outlet means 1118 and the individual tubes in th~ central bundle 113, and are then discharged at ~he face 1110 of the burner.

~ ~62~

Simultaneously, for example, a portion of a second reactant feedstream may be passed through inlet pipe 1125. Pipe 1125 is connected to and in communication with central con-duit 112 near its upper end and below tube sheet 1115.
By this means, the portion of said second feedstream may fill the interstices between and surrounding all of the tubes in the central bunch 113 as it freely flows down through said central conduit 112 and is discharged through central orifice 1111 at the face 1110 of the burner.
The upstream ends 1126 of the annular bunch of tubes 117 are connected to outlet means 1127 of annular-shaped manifold 1128. At least one inlet pipe 1129 is connected to annular manifold 1128. By this means, for example) the remaining portion of said first reactant feedstream may be introduced into annular manifold 1128, split into a plur-ality of streams which pass through outlet means 1127 and the individual tubes in the annular bundle 117, and then discharged at the face 1110 of the burner. Simultaneously, for example, the remaining portion of said second reactant 2Q feedstream may be passed through inlet pipe 1135. Pipe 1135 is connected to and in communication with annular con-duit 116 near its upper end and below tube sheet 1116.
By this means, the remaining portion of said second reactant stream may fill the interstices between and surrounding aIl of the tubes in the annular bunch 117 as it freely flows down through said annular passage 116 and is discharged through annular orifice 1112 at face 1110 of the burner.
Ignition of the multiphase mixtures of first and second reactant feedstreams takes place downstream from the face of the burner.

.
.~ , . ' .

0 4 ~

Wall brackets or tube spacersl~6 hold tubesll7 in a fixed paxallel nontouching position with respect to each other and the inside wall of outer conduit115 and the outside wall of central conduit112. Central conduit~12 and outer conduitl\5 may be radially spaced by similar means and by tube sheet nl6.
Cooling coilsll37 through which a coolant flows encircle the outside downstream end of outer conduit\15.
In another embodiment, a cored water cooled face-plate including converging nozzles terminating central conduit1t4 and annular passage116 comprises the front portion at,the extreme tip of the burner, in the manner to be shown and further described for cored faceplate ~07 in FigurelO of the drawing.
FIG. 8 is a transverse section through line 8-8 of the embodiment of the burner shown in FIG. 7. In FIG. 8, central bunch of tubes113, are enclosed by central conduit112.
The central interstitial cross-sectional area (Ic) surround-ing a suitable layout of116 parallel tubes in the bundle of tubes113 is depicted. The reactant feedstream passing longi-tudinally down through the central passage passes freely through the interstitial area surrounding the central bunch of evenly spaced tubesit3. Thus, there is provided thorough intermixing at the face of the burner of the feedstreams passing through ~he central bunch of tubes and the central interstitial area for the central conduit. The annular bunch of tubes117 in Fig. 8 is represented bylll2 parallel tubes in a single rina. There may be one to seven concentric coaxial radially spaced rings of tubes in annular passage~16 ' - ~ 16~0~

and also in the central passagen4. The inside diameter of all tubes are preferably equal. The reactant feedstream passing longitudinally down through annular passage~6 freely flows into the annular interstitial cross-sectional area (IA) surrounding the evenly spaced annular bunch of tubes~\7.
Thus, there is provided thorough intermixin~ at the face of the burner1ll~ of the reactant streams freely flowing through the annular bunch of tubes~17 and the annular interstitial cross-sectional area surrounding the annular bunch of tubes.
FIG. 9 is a schematic representation of one em-bodiment of the invention showing control means for rapidly changing throughput levels of the four feedstreams to the burner shown in FIG. 7 - up or down over the flow range for which the burner is designed in order to adjust for a change in demand for the product gas. Further, another use for the control system is to maintain the desired composition of the product gas by adjustments to the flow rates Or one or both reactants.
By the subject flow control system, the flow rates for all four of the reactant streams are separately controlled so that tne atomic ratio of oxygen to carbon in the reaction zone is maintained within a desired range, and a specified amount of raw effluent gas is produced.
While the control system shown in Figure 9 is specifically designed for a solld carbonaceous- fuel slurry, ~ ~ by simple modifications to the means for changing the flow ; rate of the fuel stream it may also control liquid and gaseous hydrocarbon fuels. These modifications are described below.
Burner11l, as previously described in Figures 7 and 8, is mounted in centraI flanged inlet1140a located in the ~ 1~2û~

upper head of conventional refractory lined free-flow syn-thesis gas generator\l41 along the central longitudinal axis.
Burneri~l is designed so that the required system output for steady-state operation may be achieved or even exceeded by a specified amount when the flow rate through all passages in both sections of the two-section burner is a maximum. The control system can change the flow rate of from one to four of the reactant streams as required. At the same time the ratio of oxidant to fuel in both sections of the burner is kept constant.
The metered feedstream of solid carbonaceous fuel slurry i.e. coal-water slurry in line\~42 is split into two feedstreamsll43 andll44 by separate flow control means in each line. The weight or volumetric rate of flow for the slurry flowing through each of the feedlines to the burner is a function of the burner design. For example the burner passages may-be sized so that one-third of the total quantity of solid carbonaceous fuel slurry flowing through linell42 may be discharged through central bunch of tubes113 in the specified velocity range. Simultaneously the remaining :
two-thirds of the total quantity of solid carbonaceous fuel slurry is d;ischarged through annular bunch of tubesll7 in the specîfied velocity range. Valvesll76 andl~77 are normally open but they may be manually or automatically operated to completely close off the stream flowing through one or both of the ~alves. This may be done for example in another ~embodiment to be further described when it is desired to turn down the burner by operating the burner either in the central section i.e. central tubesll3 and annular passagell4 or in the outer annular section i.e. annular tubesU7 and ~"' annular passage116.

.. :
.

0 162~

The portion of the slurry feedstream in linel143is pumped into the reaction zone of synthesis gas generator 1141 by way o~ positive displacement pulTlp11~5 equipped with speed controlll46, linell47, flow measurer and transmitter~i48, line~l49, normally open valve1t77 linell50, inletll20 of burner ~lt, central manifold~l9, and central bunch of tubes~3.
The slurry flow rate through linell43 is controlled by the speed of positive displacement pumpl145. The rate of slurry flow is measured and a signal a is provided by flow 10 transmitter~l48 corresponding to the flow rate of the slurry in line1143. Flow recorder-controllerl15l receives signal a and provides a signal to sp-eed control~146 to adjust up or down the speed of pumpll45, if necessary so that the charge slurry flow rate assumes a given vaIue or set point~ By this means, the adjustment to the rate of flow may be made, for example, up to 50% of the maximum flow rate for which the burner was originally designed. The set point flow rate in each case may be determined by conventional calculations based on heat and weight balances :Eor the entire system.
20. Alternately, the parameters for said calculations may be ~: ~ measured by conventional detectors and the signals respon-sive thereto including signal a, for example, may be fed to an overall control means or computerll40. The computer c:alculated value or the manually inserted set point for the desired slurry rate of flow is compared with signal a and responsive thereto signal c is provided for adjusting the speed of pumpl145. Signal c may be fed directly to speed controlll46, or indirectly by way of flow recorder-controller tl51. Alternately, flow record-controllerllSl may receive signal ~ .
.

1 16~0~

a from flow transmitterll48 and signal c from control means 1140 and compute the speed adjustment signal for the operation of speed controll146.
Simultaneously, the remainder of the slurry feed-stream in line1144 is pumped into the reaction zone of syn-thesis gas generatorl14l by way of p{:sitive displacement pump 1155 equipped in the speed controll156, linell57, flow measurer and transmitter\l58, lineU59, normally open valve1l76, line 1160, inletll29 of burnerlll, annular manifoldll28, and annular bunch of tubesl~7.
The slurry flow rate through line 1144 is controlled by the speed of positive deplacement pulTpl155. The rate of slurry flow is measured and a signal d is provided by flow transmitterll58 corresponding to the flow rate o the slurry in line\144. Flow recorder-controller~16l receives signaI d and provides a signal to speed controll\56 to adjust up or down the speed of pump1155, if necessary, so that the charge slurry flow rate assumes a given value or set point. By :
this means,~ the adjustment to the rate of flow may be made, for example, up to 50% of the maximum flow rate for which the burner was originaIly designed. Alternately, control of the slurry flow rate in linell44 may be effected by sending sigrlal d to control means1140. Signal f from control means 1140 is sent to flow recorder-controller1~6l or directly to speed control1156 for controlling the speed of pump1155 in the : manner described previously for controlling the flow rate , ~
:~ ~ for the slurry in line1143.

~; : Simultaneously, the proper amount of free-oxygen containing gas in linel162 for the partial oxida`tion o~ the : ``''' .

1 162~

related amount of solid carbonaceous fuel slurry flowing in line1142, is split into two streamsU63 and1164 by flow control means in each line~ The flow rate for the free-oxygen con-taining gas flowing through each of the feed lines to the burner is a function of the burner design. For example, the burner p~ssages may be sized so that one-third of the total quantity of free-oxygen gas flowing through line~62 may be discharged through annular passage1l4 at the specified veloc-ity range. Valves~165 and\~66 may be manually or automatic-ally operated to respectively adjust the flow rate in lines 1163 and1l64. For example, an adjustment of up to 50~ of the maximum flow rate for which the burner was originally de-igned for may be made.
Simultaneously, the remaining two-thirds of the total quantity of free~oxygen containing gas is discharged through annular passagel16 of the second section o~ the burner in the specified velocity range. ~alvesl~65 andU66 are normally open but they may be manually or automatically operated to partia~ly close off the stream flowing through one or both of the valves. In the embodiment to be further descr~ibed, the burner may be operated in either the central section or in the outer section hy completely closing re-spectively valvell66 orl165, while keeping the other valve open or partially closed. Valves\165 and~66 are normally operated simultaneously so that the change in the quantity of flow through linesn63 andll64 is the same. Simultaneously, adjustments to speed controlsll46 and1\56 a~e made to effect a corresponding change in the slurry flow rate through lines 1143 andl144. By this means, the O/C atomic ratio in the reaction zone is maintained at the given value.

, ' The portion of the free-oxygen containing gas stream in linell63 is introduced into the reaction zone of the synthesis gas generatorl~4l by way of flow transmitter 1167, line~l68, normally open valvell65, line1170, and inletl~25 to cen'tral passagell4 of burnerlll. The rate of flow for the free oxygen containing gas through linell63 is controlled by valvell65. The rate of flow for the free-oxygen containing gas is measured and a signal b is provided by flow trans-mitterl~67 corresponding to the flow rate for the free-oxygen containing gas in linell63. Flow recorder-controller q74 receives signal b and provides a signal to valvell65 to adjust up or down, the rate of flow, if necessary, so that the free-oxygen containing gas flow rate assumes a given value or set point. By this means, the adjustment to the rate of flow may be made, for example, up to 50g6 of the maximum flow rate for which the burner was originally designed. Conventional or computerized calculations based on heat and weight balances for the system may be made to determine the set point, as' previously described.
Simultaneously, the remainder of the free-oxygen cc>ntaining gas feedstream in linell64 is introduced into the reaction zone of synthesis gas generator\141 by way of flow transmitterll71, linell72, normally open valvell66, linetl73, and inletll35 to annular passage116 of burnerlll. The rate of Elow for the free-oxygen containing gas through linell64 is controller by valvel~66. The rate of flow for the free-oxygen eontaining gas is measured and a signal e is provided by flow transmitterll71'corresponding to the ~low rate for the free-oxygen containing yas in linell64.

~ 1~2~46 Flow recorder-controllerll75 receives signal e and provides a signal to valvell66 to adjust up or down, the rate of flow, if necessary, so that the free-oxygen containing gas flow rate assumes a given value or set point. By this means, the adjustment to the rate of flow may be made, for example, up to 50~ of the maximum flow rate for which the burner was originally designed.
Alternately, control means~0 may be employed to control the rate of flow of one or both streams of free-oxygen containing gas. Thus, signal b from flow transmitter 1~67 and/or signal e from flow transmitter~71 are compared in control meansll40 with the computer calculated value or the set point. Responslve thereto signal j and/or h are respec-tively provided for partially opening or closing valve1165 and/or valveU66. Alternately, flow recorder-controlIerID4 and/or1l75 may receive respectively signals j and h and/or signals b and e and compute the flow rate adjustment signal for the operation of valve1165 and/or1~6.

.
In normal operation, all of the valves in the sys-tem are open so that the fIow through the burner is about that of Design Conditions. A turndown of 50% of Design Con-ditions for burner1l~is achieved, for example, by ~imuItan-eously decreasing the speed~of pumpsi~45 andl155 and partially closing valves\~65 andU66 so as to reduce by~about 50% the respective flow rates of both slurry streams in lines~)50 and : . .
1160 and both streams of free-oxygen containing gas in lines 1170 andll73. Flow control valves1l77 andll76 remain open. The design value for the ratio of the oxygen atoms in the free-oxygen containing gas to the carbon atoms in the solid car-.
bonaceous fuel slurry (O/C atomic ratio) in each section of the burner and in the reaction æone remains unchanged.
'~ ' ' ¢

Speed controls1146 andll56 a~d valves1165 and\K6 may be operated manually or automatically by control means\~0, as previously described. The input to flow control means~40 may be manual or a signal from a computer, analyzer, or sensor. Control means~t40 comprises conventional circuits and components for providing signals i.e. pneumatic or elec-tronic to operate said speed controls and valves. The aforesaid procedure for reducing the total flow through the burner is applicable only when the discharge velocities for the various feedstreams do not fall ~elow the flame propaga~ion tion velocity.
Other ways of turning down burner1l~is by main-taining flow through either central conduit114, or outer annular passagel16, and their respective tubes. This turn-down procedure may be combined with the previously mentioned procedure in which the flow rate in either or both sections~
of the burner may be reduced, say up to 50%. Either manual or automatic control may be used to shut off one set of tubes and its related surrounding passage. By such means, two other ranges of flow may be obtained. For example, as shown in FIG. g, one-third of the Design Conditions of flow through burner1ll may be achieved by only employing central conduitll4 and the associated central bunch of tubes113. In such case valvesU77 and~65 are open and valves1176 andll66 are closed. Valves176 and1166 which are normally open may be closed manually or respectively by signals g and h from control meansl140. This rate of flow may be further reduced, say up to 50% as previously described by now operating speed control1~6 and partially closing val~ell65. In another . , .

1 ~620~

exæTn?le, two-thirds Or the Design Conditions of flow through burnerlll may be achieved by only employing rlow through outer annular passagell6 and the ~ssociated annular bunch of tubesll7. In such case, valves~76 andll66 are open and valves ll77 and ~65 are closed. valves\l77 and l~65 which are normally open may be closed manually or respectively by signals i and j from control means1140. This rate of flo~ may be further reduced say up to 50~ by now operating speed controlll56 and partially closing valvel~66.
The size o~ the burner tubes and conduits may be changed for other splits. For example, in another embodi-ment, 1/4 of the Design Conditions of flow f`or the fuel and oYidant streams may be passed through the central tubes and central conduit and the remaining 3/4 of the Design Condi-tions of flow for the fuel and oxidant streams may be passed through the annular tubes and annular passage.
FIG. ~o is a vertical longitudinal schematic rep-resentation of another embodiment of the sub;ect burner.

Two pre-mix chambers in series are located in the central conduit and also in the annular passage. The ends of the central and annular bunches of tubes are retracted upstream rrom the face of the burner. In FIG. IO, burner280 comprises central conduit281 which in part constitutes the wall282 between central passageZ133 and coaxial radially spaced annular passage 284, two rows of a central bunch of parallel tubes~85 that pass longitudinally through the upper portion of central passage~83 and having upstream ends~86 that pass through tube sheet287 making a gastight hermetic seal there-with, and dowr~stream ends 188 which are retracted upstream 3 ~rom face289 at the downstream end of burner~80, coaxial concentric radially spaced outer conduit~90 surrounding said annular passage 284 along lts length, two rows Or annular b~lnch Or p2rallel tubes 295 that p~ss longituainally throu~h an!~ular passage '84 ~ ith u?stream ends 296 passing through tube sheet 97 and making an ~as,ight seal therewith and having downstream ends 298 retracted upstream from face ~89, annular manifold 2100 in communication with the upstream ends .96 o~ said annular bunch of tubes 295, manifold ~101 which may be cylindrical-shaped in communication with the upper ends 286 o~ said central bunch of tubes 285, inlet means aO2 for introducing a first feedstream into said central manifold 10 2101, inlet means2103 for introducing a second feedstream into said central passage 283 and in the interstices surrounaing said central bunch of tubes 285, inlet means 2104 for introducing a third feedstream into said annular mani~old ~100, inlet means ~105 for introducing a Iourth feedstream into said annular passage ~84 and into the interstices surrounding the annular bunch of tubes295, cooling coils ~106 which encircle the outside diameter of outer conduit 280 along its length, and cored cooling chamber 2107 at the downstream tip of the burner.
I isc shaped central tube sheet 2B7 closes off central passage283 below its upstream end. Similarly, annular shaped tube sheet 297 closes o~f annular passage 284 below its upper end. Conventional means i.e. welding, turning, crlmping, threading, rolling may be employed to provide a pressure and gastight hermetic seal or joint where the central and annular bunches of tubes penetrate the respective tube sheets. Mechanical pressure fittings and coupling devices may be also employed.
Plate 2108 which may be disc-shaped seals off the 3 upper end of central conduit~f31. The space between plate 2108 and tube sheet ~87 constitutes said central manifold ~101.
13y this means, ~or example, a portio~l o~ a ~irst reactant feedstream in ~eed pipe 2102 may be introduced into central 9 ~82~

1 ~L62~6 manifold2101 and then split into a plurality of streams which pass through tube sheet287 and the individual tubes in central bundle285. Annular shaped disc2109 seals off the upper end of annular passage284. The space between annular disc ~09 and annular t~be sheet~97 constitutes annular manifold2100. Simultaneously and concurrently with the introduction of the first reactant feedstream, the third reactant feedstream in feed pipe2104 may be introduced into annular manifold~100, split into a plurality of streams which pass through tube sheetl97 and the individual tubes in annular bundle~95.
Wall brackets or tube spacers2115 hold the in-dividual tubes in annular tube bundle~95 in a fixed parallel nontouching relationship with respect to each other and the inside of outer conduit290. Similarly, wall brackets or tube spacers2116.hold the individual tubes in central tube bundle285 in a fixed parallel nontouching relationship with respect to each other, the inside diameter of central conduit ~81, and the outside diameter of central conduit281.
While the pre-mix zones i~ the embodiment in FIG.
l~ are shown as comprising two separate coaxial central pre~
.

mix chambers U17 and ~18 in series in central conduit~83, and two separate coaxial annular pre-mix chambers ~19 and ~: 2120 in series in annular passage~84, the pre-mix zone of other embodiments of the subject invention may actually comprise one or more, such as 2 to 5 coaxial central and/or annular pre-mix chambers~ Each central pre-mix chamber, except for the first chamber in the line, comprises a coaxial cylindrical body portion ~21 followed by a coaxial at least . , .

- 72 ~ 2~4~
partially converging frusto-conical outlet portion ~22 that may optiorally develop into a normal cylindrical portion 2123. This outlet portion is shown in FIG.~o as a converging . central nozzle ~24 which terminates at the downstream face of the burner. Optionally, nozzles 124 and'133 to be further described may be made from a thermal and wear resistant material i.e. silicon carbide or tungsten carbide.
The first central pre-mix chamber in the line may have a straight coaxial cylindrical body portion ~25, that discharges through circular orifice~l26 directly into the next in l;ne central coaxial pre-mix chamber ~18. Pre-ferably, the inlet to the first central pre-mix chamber21I7 is a portion of a converging frusto-conical shaped section U27.
Each of the coaxial annular shaped pre-mix chambers 2120 except the first annular shaped chamber7119 comprises a coaxial generated normal cylindrical annular body portion ~30 followed by a coaxial generated at least partially converging frusto-conical shaped annular outlet portion~l31 that may optionally develop into a coaxial generated normal cylindrical annular portion2132. This outlet portion is shown in FIG.lO as a converging annular exit nozzle ~33 which terminates at the downstream face of the burner. The first coaxial annular shaped pre-mix chamber ~19 comprises a coaxial generated normal cylindrical annular body portion - ~34 that discharges through annular orifice ~35 into the next in line coaxial annular shaped pre-mix chamber2120.
Preferably, the inlet to the first annular shaped pre-mix chamber2119 comprises a portion of a coaxial generated con-verginy frusto-conical shaped section2136.

~ ~20~

Cored faceplate2107 comprises a front portionll37 at the extreme tip of the burner, which may be flat or curved, and which contains a coaxial central annular shaped cooling cham~er2138 surrounding the central condui, e~it nozzle2124 and/or a coaxial radially spaced annular shaped cooling chamber2139 surrounding said annular exit nozzle ~33 at the tip of the ~urner. The cooling chamber may be joined to the otherwise flat ~urner tip such as shown in FIG. 7, or it may be an extension of the central and outer conduits.
Cold cooling water in line2140 enters annular shaped cooling cham~er2139, splits by means o~ baffles and flows about 180, and leaves by way of an opposite outlet which is con-nected to outer coils2106. Cooling water is introduced into central annular cooling chamber2138 by way of line ~45 which is connected to passage2146 that passes longitudinally down through wall~82 in central conduit281. The cool water splits by means of baffles, flows about 180 around central cooling channel~l38, and leaves by way of an opposite coaxial longitudinal passage ~not shown) similar to passage 146 but 2D in another location in wall~82.
Optionally, a gaseous feedstream selected ~rom the group consisting of steam, free-oxygen containing gas, CO2, N2, fuel gas, recycle portion of the product gas, and mixtures thereof may be introduced into at least one of the ~central and/or annular pre-mix chambers by way of at least one inlet pipe ~49 which is connected to at least one longi-tudinal passage ~47 in wall~82 of central conduit281, and ~t least one branch passageZ148 connecting longitudinal passage ,:: , ':
147 with said pre-mix chambers.

:

l 1~2~8 Figure 11 shows a further embodiment which is equiv-alent to the construction described above with reference to Figures 1 and 2, with the exception that the inner central conduit 15 is replaced by a central bundle of helical tubes 15'. The same reference numerals have been used for equiv-alent features in the construction of Figures 1 and 2 and the corresponding construction of Figures 11 and the follow~
ing description of the latter construction will be confined ; to the features of that construction which differs ~rom the construction of Figures 1 and 2.
In Fig. 11, one embodiment of the swirl burner is shown in diagrammatic longitudinal cross-section. This view comprises unobstructed central coaxial retracted central bundle o~ helical tubes 15' which is surrounded by outer concentric coaxial conduit 16. One coaxial concentric ring of two helical coils is shown. Spacing and supporting means 18 may provide a plurality of related free-flow helical-shaped passages 17 in the cylindrical space surrounding the central bundle of helical tubes 15'.
In another embodiment, not shown, the inlets~ and outlets of the separate helical coils in central bundle of helical tubes 15' are located at the intersections of a plurality of coaxial concentric rings and a plurality o~ evenly spaced radial rows. The sides of the helical : G~ ~ coils in adjacent concentric rings may or may not touch.
By this means the feed stream entering outer conduit 16 ~;~ by~way of inlet 8 may pass down through a plurality of heli-cal passages or into the interstices between the helical coils.
~ E~it orifices 20' at the downstream~tips of the plur-ality of helical coils 19 in the central bundle of helical tubes 15' preferably are circular in cross-section and ter-`minate in a plane perpendicular to the longitudinal axis of the burner. Outer conduit 16 terminates at the down-stream end of the burner with converging nozzle 21.
In the operation of the burner as shown in Fig. 11, ; either reactant stream i.e. see Table II supra, may enter : `,i~ ~; :

:

1 ~20~

the burner by way of inlet 9 and pass directly into central manifold 25a. Central manifold 25a is a closed cylindrical chamber comprising upper closed head 26 and lower tube sheet 27. The upstream open ends 28 of the plurality of helical coils 19 pass perpendicularly through tube sheet 27 and make gas-tight hermetic seals therewith. By this means, the upstream ends of helical passages 17 in outer conduit 16 are closed.
The feed stream in central manifold 25ais split into a plurality of streams which swirl down through the plurality of free-flow helical coils 19, out through exit orifices 20, and into pre-mix zone 25, as shown in Fig. ll~ Simul-taneously and concurrently, the second reactant stream enters the subject burner by way of inlet 8 and is split into a plurality of streams which swirl down from the upstream portion 30 of oute~ conduit 16 through the plurality of free-flow helical passages 17 or down through the interstices between individual spaced helical coils, or both. The two reactant streams impinge in pre-mix zone 25 where intimate mixing of the streams takes place. Further, direct heat exchange between the two reactant streams takes place in pre-mix zone 25. The temperature in the pre-mix zone is controlled so that a controlled amount of the liquid carrier may be vaporized without burning i.e. from 0 to 100 vol.
% say about 2 to 80 vol. %. Temperature control in the pre-mix zone may be :

, :

0~ 6 e~fected by controlling such factors as dwell time and heat content Or the entering streams, and amount of external cooling such as by coils 4, if any. Pre-mix zone 25 is substantially free from any obstruction to the free-flow of the materials passing therethrough.
The veloclty of the slurry of solid carbonaceous fuel in liquid carrier passing through exit orifices 20 of the central bundle of helical tubes 15'or alternately exiting from passages 17 is in the range of about 5.0 to 100 ft. per sec., such as 10 to 50 ft. per sec., say about 2 to 20 ft. per sec. The corresponding velocity for the free oxygen containing gas simultaneously passing through the other passage in the burner optionally in aamix;ture with--steam, is in the range of about 150 feet per second to sonic v~elocity, such as about 100 to 600 ft. per sec., say about 2~0 to 500 ~t. per sec. The slurry of solid carbonaceous fuel in liquid carrier enters the pre-mix zone in liquid phase at a temperature in the range of about ambient to 500F., and below the vaporization temperature of the liquid ; ~ 20 carrier. The pressure may be for example in the range o~ about 76 to 4500 psia. While simultaneously, the free-oxygen containing gas stream, optionally in admixture with steam, enters into the pre-mix zone at a temperature in the range of about ambient to 1200F., say about 100 to 600F., and at a pressure in the range of about 76 to 4500 psia.
Intimate mlxing and direct heat exchange takes place between the two reactant streams in the pre-mix zone. Volatilization of the liauid carrier in the ?re-mix zone ~ay amount to abcut 0 to 100 vol. %, say about 20 to 35 vol. ~0 when the free-oxygen containing gas is introduced at a temperaiure in the range of about 300 to 600F., or from about 70 to 100 - ~7 -vol. % when the free-oxygen containing gas is introduced as air preheated to a temperature in the range of about 1000 to 1200F. The multiphase mixture in the pre-mix ~one is at a temperature below its autoignition temperature.
The multiphase mixture leaves burner 1 by way of exit orifice 21 at a discharge velocity in the range of about 75 to 600 ft. per sec., say about 150 to 350 ft. per sec., and above the flame propagation velocity and passes downwardly directly into the unobstructed reaction zone of the partial oxidation gas generator.
The downstream end of outer conduit 16 as shown in Fig. 11 may, in another embodiment, have the form as shown in Fig. 3 as described above with reference to those Figures.
As shown in Fig. 12, in a further embodiment, at the down-stream end of outer conduit 16 as shown in Fig. 11, theexit nozzle 35, which is made from a wear resistant material such as tungsten carbide or silicon carbide, comprises a frusto-conical converging rear portion 22 which develops into a frusto-conical diverging front portion 23. The frusto-conical converging outside diameter of exit orifice 35 issupported by coaxial ~rusto-conical mating converging cavity 36 in annular cooling chamber 2. For example, exit orifice 35 made from tungsten carbide may be connected to the down-stream tip of outer conduit 16 by joining the back surface 37 of cooling chamber 2 to the front surface of end flange 38 at the downstream end of outer conduit 16. Cooling water may be introduced into cored section 24 of cooling chamber 2 in the manner shown for inlet pipe 3 in Fig. 1. Optionally~
a cooling coil may encircle outer conduit 16 in the manner shown for coil 4 in Fig. 1. Hot high velocity slurries of solid fuel are abrasive. The life of the subject burner may be considerably extended by making exit nozzle 35 from ; a wear resistant material.
Fig. 13 is a vertical longitudinal schematic represen-tation of another embodiment of the subject swirl burnerbut with the additon of pre-mix and high turndown features.
This construction corresponds in many respects to the 1 1~20~B

construction shown in Fig. 10 and like reference numerals have been used for similar parts which will therefore not be described again in detail. Two pre-mix chambers in series are located in the central conduit and also in the annular passage. The ends of the central and annular bundles of helical tubes are shown retracted upstream from the face of the burner. The burner may be operated with feed streams passing through either the central, annular, or both bundles of helical tubes and through the plurality of helical pas-sages in the related conduits surrounding said bundles oftubes. By this means, flow through the burner may be turned up or down. In Fig. 13, burner 280 comprises a central section and an annular section. The central section is similar to the embodiment shown in Fig. 11. A central bundle of helical tubes 285' passes down through the upper portion of cent~al passage 283. The central section of Fig. 13 includes a single coaxial concentric ring, with two helical coils 289. However, the central sections of other embodi-ments may include a plurality of coaxial concentric rings containing a plurality of helical tubes. Upstream inlets 286' of helical coils 289 pass through tube sheet 287 and make a gas-tight hermetic seal therewith. These inlets are shown lying in two radial rows spaced 180 apart. Down-stream ends 288' are retracted upstream from face 2137 at the downstream end of burner 280. Supporting and optionally spacing means 218 may provide a plurality of related free-flow helical-shaped passages 217 in the cylindrical space surrounding the central bundle of helical tubes 2~5'.
In the annular section of burner 280, coaxial con-centric radially spaced outer conduit 290 surrounds annular passage 284' along its length. An annular bundle of helical tubes 295' passes down through annular passage 284' and comprises four coaxial concentric rings of helical coils ~95'. Only two of the plurality of radial rows are shown.
Further, two of the plurality of helical coils are shown in each concentric ring for illustrative purposes only.
For clarity~our of the helical coils have been cut-off near ~ "

- \
~ ~8~04~

the upstream inlets. The actual number of helical coils in a concentric ring is a function of pipe size, ring diam-eter, and spacing between radial rows. Spacing and support-ing means 291 may provide a plurality of related free-flow helical passages 292 in the annular space surrounding the annular bundle of helical tubes 295i. Upstream inlet ends 296' of concentric helical coils 295' pass through tube sheet 297 and make gas-tight seals therewith. Downstream tube outlet ends 298' are shown retracted upstream from face 2137. In another embodiment (not shown) in which there are no pre-mix chambers in annular passage 284', the down-stream ends 298' of helical coils 295' may be flush with burner face 2137. Annular manifold 2100 is in communication with the upstream ends 296' of said annular bunch of tubes 295'. Manifold 2101, which may be cylindrical-shaped, is in communication with the upper ends 286' of said central bunch of tubes 285'.
Inlet means 2102 is employed for introducing a first feed stream into said central manifold 2101. Inlet means 2103 near the upstream end of central conduit 282 is used to introduce a second feed stream into the upstream end of central passage 283 and from there into the helical pas-sages and/or interstices surrounding central bunch of tubes 285'. Similarly, inlet means 2104 is employed for introduc-ing a third feed stream into annular manifold 2100. Inletmeans 2105, near the upstream end of outer conduit 290 is used to introduce a fourth feed stream into the upstream end of annular passage 284' and from there into the helical passages and/or interstices surrounding the annular bunch of tubes 295'. Optionally to provide additional swirl, ; inle-ts 2103 and/or 2105 may be oriented so that the second and fourth feed streams may be respectively introduced tan-gentially into central conduit 281 and outer conduit 290.
Optionally, inlets 2102 and/or 2104 may be oriented so that the first and third feed streams may be respectively intro-duced through the top of manifolds 2101 and 2100. Wall brackets or tube spacers 291 hold the individual tubes in I ~B2~46 annular bundle of helical tubes 295' in a fixed touching or non~touching relationship with respect to each other and the inside of outer conduit 290. Similarly, wall brackets or tube spacers 218 hold the individual tubes in central bundle of helical tubes 285' in a fixed touching cr non-touching relationship with respect to each other and the inside diameter of central conduit 281.
While the pre-mix zones in the embodiment in Fig.
13 are shown as comprising two separate coaxial central pre-mix chambers 2117 and 2118 in series in central conduit 283, and two separate coaxial annular pre-mix chambers 2119 and 2120 in series in annular passage 284, the pre-mix zone of other embodiments of the subject invention may actually comprise one or more, such as 2 to 5 coaxial central and/or annular pre-mix chambers as described above with reference to Fig. 10.
~ odifications and variations of the above described embodiments may be madewithin the spirit and scope of the invention as defined in the appended claims.

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Claims (56)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A burner for intimately mixing together at least two separate feedstreams comprising a pumpable slurry of solid carbonaceous fuel in a liquid carrier, and a feedstream of free-oxygen containing gas, with or without admixture with a temperature moderator to produce a multiphase mixture for reaction by partial oxidation in a gas generator to produce raw synthesis gas, fuel gas or reducing gas comprising mixtures of H2, CO, CO2 and at least one material from the group H2O, N2, A, CH4, H2S, and COS, and entrained particulate matter characterized by: central flow means coaxial with the central longitudinal axis of the burner and having upstream inlet means through which a first feedstream or feedstreams may be separately introduced, and downstream outlet means that discharges into a central coaxial pre-mix zone; an outer first coaxial conduit concentric with and surrounding said central flow means and having an upstream inlet through which a second feedstream may be separately introduced and a coaxial circular exit outlet terminating said outer conduit at the downstream tip of the burner and comprising a partially converging frusto-conical rear portion and a right cylindrical front portion which terminates at the downstream face of the burner, and the height of the front cylindrical portion of said exit nozzle is in the range of about 0.1 to 1.0 times its own diameter, an annular shaped face-cooling chamber surrounding said exit outlet at the burner tip;

wherein the downstream termination of said central flow means is retracted upstream from the downstream face of the burner a distance of two or more times the minimum diameter of said outer conduit downstream outlet to provide said central pre-mix zone comprising one or more communicating pre-mix chambers in tandem and coaxial with the central longitudinal axis of the burner; and means for supporting said central flow means and outer conduit with respect to each other to provide a passage or passages therebetween through which said second feedstream may separately pass concurrently with said first feedstream(s) into said central pre-mix zone where said feedstreams are intimately mixed together and a controlled amount in the range of about 0 to 100 vol. % of the liquid carrier is vaporized without burning to produce said multiphase mixture prior to being discharged through said outer conduit exit outlet at a discharge velocity which is greater than the flame propagation velocity.

2. A burner according to Claim 1 wherein said central flow means comprises a single central conduit.

3. A burner according to Claim 2 wherein there is provided an intermediate coaxial conduit concentric with the central and outer conduits and having an upstream inlet through which a third feedstream may be separately introduced, and a downstream exit nozzle terminating the intermediate conduit, and the tip of said intermediate conduit exit nozzle is retracted upstream from the downstream face of the burner a distance of about 0 to 12 times the minimum diameter of said outer conduit downstream exit nozzle;

and means for radially spacing the central, intermediate, and outer conduits with respect to each other to provide intermediate and outer coaxial annular passages, and the intermediate annular passage is situated between the outside diameter of the central conduit and the inside diameter of the intermediate conduit and is the passage through which the third feedstream may separately pass concurrently with a first feedstream passing through said central conduit and discharge into the central pre-mix zone where a multiphase mixture of the first and third feedstreams is produced, and the outer annular passage is situated between the outside diameter of the intermediate conduit and the inside diameter of the outer conduit and is the passage through which a second feedstream may separately pass concurrently with the first and third feedstreams, and then be intimately mixed with said feedstreams.

4. A burner according to Claim 3 wherein the walls of said intermediate conduit contain a plurality of small diameter holes or passages to permit said second feedstream flowing in said outer annular conduit to pass through and mix with one or both of the other feedstreams simultaneously flowing at a lower pressure through the other passages or pre-mix zone of the burner.

5. A burner according to Claim 4 including blocking means at the downstream outlet of said outer annular passage for completely or partially closing the downstream outlet of said outer annular passage.

6. A burner according to any of Claims 3, 4 or 5 wherein the tip of said intermediate conduit exit nozzle is retracted upstream from the downstream face of the burner a distance in the range of about 1.0 to 5 times the minimum diameter of the outer conduit exit nozzle.

7. A burner according to Claim 3 wherein a pumpable slurry of solid carbonaceous fuel is passed through either the central conduit or through the intermediate annular passage, a free-oxygen containing gas is simultaneously passed through the unused one of said two passages, and a gaseous feedstream from the following group is simultaneously passed through the outer annular passage:steam, free-oxygen containing gas, CO2, N2, a recycle portion of the product gas, and mixtures thereof.

8. A burner according to Claim 1 wherein the central flow means comprises a central bundle of open-ended helical tube(s) whose central longitudinal axis is coaxial with the central longitudinal axis of the burner and comprising one or more helical tubes having inlet portions in communication with said upstream inlet means by which a first reactant feedstream may be introduced and then split into a plurality of separate streams, when a plurality of helical tubes are provided, to pass down through said central bundle of helical tube(s) and then be discharged through the downstream end(s) of said tube(s) into the central pre-mix zone; the outer conduit comprises a coaxial cylindrical conduit concentric with and surrounding said central bundle of helical tube(s), said outer conduit being closed near the upstream end so that the inlet por-tion(s) of said helical tube(s) may pass through and make a gastight seal therewith and having an unobstructed circular downstream outlet at the tip of the burner; and upstream inlet means in communication with said outer conduit through which a second reactant feedstream may be separately introduced and split into a plurality of swirling streams which may pass down through one or more related helical-shaped passage(s) formed in the cylindrical space that surrounds said central bundle of helical tube(s) and/or through the inter-stices, if any, between said helical tubes and then be intimately mixed with said first reactant feedstream in said central pre-mix zone; and means for supporting the central bundle of helical tube(s) with respect to said outer conduit and each other.

9. A burner according to Claim 8 wherein said central bundle of helical tube(s) comprises 1-200 open-ended helical coils.

10. The burner as described in Claim 1 wherein a pumpable slurry feed-stream comprising a solid carbonaceous fuel selected from the group consisting of coal, lignite, coke from coal, char from coal, coal liquefaction residues, petroleum coke, particulate carbon soot, and solids derived from oil shale, tar sands, pitch, bits of garbage, dewatered sanitary sewage, and semi-solid organic materials and a liquid carrier selected from the group consisting of water, liquid hydrocarbonaceous material, and mixtures thereof, and liquid CO2 is connected to either said central flow means or said outer conduit, and a free-oxygen containing gas feedstream selected from the group consisting of air, oxygen-enriched air, and substantially pure oxygen is connected to the remaining free passage.

11. The burner as described in Claim 8 wherein a pumpable slurry feed-stream comprising a solid carbonaceous fuel selected from the group consisting of coal, lignite, coke from coal, char from coal, coal liquefaction residues, petroleum coke, particulate carbon soot, and solids derived from oil shale, tar sands, pitch, bits of garbage, dewatered sanitary sewage, and semi-solid organic materials and a liquid carrier selected from the group consisting of water, liquid hydrocarbonaceous material, and mixtures thereof, and liquid CO2 is connected to either said central flow means or said outer conduit, and a free-oxygen containing gas feedstream selected from the group consisting of air, oxygen-enriched air, and substantially pure oxygen is connected to the remaining free passage.

12. The burner as described in Claim 10 or 11 wherein said semi-solid organic materials are asphalt, rubber and rubber-like materials including rubber automobile tires.

13. The burner as described in Claim 10 or 11 wherein steam is admixed in the gas feedstream.

14. The burner as described in Claim 1 wherein said face-cooling chamber and outer conduit outlet constitute a single piece of thermal and wear resistant material.

15. The burner as described in Claim 14 wherein said thermal and wear resistant material is tungsten carbide or silicon carbide.

16. The burner as described in Claim 1, 3 or 8 wherein the outer conduit outlet is in the shape of a long-radius nozzle.

17. The burner as described in Claim 1, 3 or 8 further provided with a coaxial annular shaped cooling chamber surrounding the outer conduit exit nozzle, and cooling coils that encircle the outside diameter of the burner along its length.

18. The burner as described in Claim 1 wherein the central pre-mix zone comprises a plurality of pre-mix chambers and each pre-mix chamber except the first chamber comprises a coaxial cylindrical body portion followed by a coa-xial at least partially converging frustoconical outlet portion, and said first pre-mix chamber comprises a straight coaxial cylindrical body portion that discharges directly into the next in line coaxial pre-mix chamber.

19. The burner as described in Claim 18 wherein the frustoconical out-let portion develops into a straight cylindrical portion.

20. The burner as described in Claim 18 wherein the converging outlet portion of said pre-mix chambers is made from tungsten carbide or silicon carbide.

21. The burner as described in Claim 1, 3 or 8 wherein said pre-mix chambers are successively numbered 1 to 5 and the ratio of the diameter of any one of said chambers to the diameter of the next chamber in the line may be in the range of about 0.2-1.2; and the ratio of the length of any one pre-mix chamber to the length of the next pre-mix chamber in the line may be in the range of about 0.1-1Ø

22. A burner for the partial oxidation of reactant fuel feedstream sel-ected from the group consisting of a pumpable slurry of solid carbonaceous fuel in a liquid carrier, liquid or gaseous hydrocarbon fuel, and mixtures thereof with a reactant feedstream of free-oxygen containing gas, comprising:
a central conduit, said central conduit being closed at the upstream end and having an unobstructed downstream circular exit orifice at the tip of the burner; an outer conduit coaxial and concentric with said central conduit a-long its length and in spaced relationship therewith and forming an annular passage therebetween, said outer conduit and annular passage being closed at the upstream end and having an unobstructed downstream annular exit orifice at the tip of the burner and wherein the central longitudinal axis of the annular passage is parallel to the central longitudinal axis of the burner throughout its length; a central bunch of tubes passing through the closed end of said central conduit and making a gastight seal therewith, the tubes of said central bunch of tubes extending down said central conduit and having upstream inlet means for introducing a first feedstream and downstream ends through which said first feedstream is discharged, and wherein the downstream ends of said central bunch of tubes are retracted upstream from the burner face a distance of about 0 to 12 times the minimum diameter of the central conduit exit orifice at the tip of the burner, means for spacing and support-ing said central bunch of tubes with respect to the inside wall of said central conduit and to each other, and upstream inlet means for introducing a second feedstream into said central conduit and the passages and interstices when present between the central bunch of tubes; an annular bunch of tubes passing through the closed end of said annular passage and making a gastight seal therewith, the tubes in said annular bunch of tubes having upstream inlet means for introducing a third feedstream into said tubes and downstream ends through which said third feedstream is discharged, and wherein said downstream ends of said annular bunch of tubes are retracted upstream from the burner face a distance of about 0 to 12 times the minimum width of the annular exit orifice at the tip of the burner, means for supporting said annular bunch of tubes with respect to the inside wall of said annular passage and to each other, and upstream inlet means for introducing a fourth feedstream into said annular passage and the passages and interstices when present between the annular bunch of tubes in said annular passage; and wherein ignition of mix-tures of the reactant feedstreams takes place downstream from the face of the burner.

23. The burner as described in Claim 22 wherein the partial oxidation of the reactant fuel feedstream with the reactant feedstream of free-oxygen containing gas occurs with admixture with a temperature moderator.

24. The burner as described in Claim 22 wherein the tubes in the central bunch of tubes are symmetrically spaced and parallel to each other and to the central longitudinal burner axis and extend along the central conduit, and the annular bunch of tubes are symmetrically spaced and parallel to each other and to the central longitudinal burner axis and extend along the annular passage.

25. The burner as described in Claim 22 wherein the tubes in the central and annular bunches of tubes are helical tubes and a plurality of related helical-shaped passages are formed in the cylindrical and annular spaces that respestively surround the central and annular tube bundles.

26. The burner as described in Claim 22 wherein the downstream ends of the central bunch of tubes are retracted upstream from the face of the burner a distance of about 3 to 10 times the minimum diameter of the central conduit exit orifice to provide a central pre-mix zone comprising one or more separ-ate communicating in-line central pre-mix chambers and/or the downstream ends of the annular bunch of tubes are retracted upstream from the face of the burner a distance of 3 to 10 times the minimum width of said annular exit orifice to provide an annular pre-mix zone comprising one or more separate communicating in-line annular pre-mix chambers in series.

27. The burner as described in Claim 26 wherein the central pre-mix zone comprises 2 to 5 coaxial cylindrical shaped central pre-mix chambers in series in said central conduit and/or the annular pre-mix zone comprising 2 to 5 coaxial annular shaped pre-mix chambers in series in said annular passage.

28. The burner as described in Claim 26 wherein each of the cylindrical shaped central pre-mix chambers in the central conduit except the first cylin-drical shaped chamber comprises a coaxial cylindrical body portion followed by a coaxial at least partially converging frusto-conical shaped outlet portion, said first cylindrical-shaped pre-mix chamber comprises a converging inlet portion and a normal coaxial cylindrical body portion that discharges through a circular orifice directly into the next in-line coaxial cylindrical shaped pre-mix chamber; and wherein each of the annular shaped pre-mix chambers except the first annular shaped chamber in the annular passage comprises a coaxial generated normal cylindrical annular body portion followed by a coaxial generated converging frusto-conical shaped annular outlet portion, and said first annular shaped pre-mix chamber comprises a coaxial generated converging inlet portion and a normal cylindrical annular body portion that discharges through an annular orifice directly into the next in-line coaxial annular shaped pre-mix chamber.

29. The burner as described in Claim 28 wherein the frusto-conical shaped outlet portion of each of the central pre-mix chambers in the central conduit except the first cylindrical shaped chamber develops into a straight cylindrical portion.

30. The burner as described in Claim 28 wherein the frusto-conical shaped annular outlet portion of each of the pre-mix chambers except the first annular shaped chamber in the annular passage develops into a straight cylindrical portion.

31. The burner as described in Claim 28 wherein the outlet portions of said pre-mix chambers are made from tungsten carbide or silicon carbide.

32. The burner as described in Claim 31 wherein said central pre-mix chambers in said central pre-mix zone are successively numbered 1 to 5 and the ratio of the diameter of any one of said chambers to the diameter of the next chamber in the line may be in the range of about 0.2-1.2; and the ratio of the length of any one pre-mix chamber in said central pre-mix zone to the length of the next pre-mix chamber in the line may be in the range of about 0.1-1.0; and/or said pre-mix chambers in said annular passage are successively numbered 6 to 10 and the ratio of the annular width of any one of said chambers to the width of the next chamber in the line may be in the range of about 0.1-1.2, and the ratio of the length of any one pre-mix chamber in said annu-lar passage to the length of the next pre-mix chamber in the line may be in the range of about 0.1-1Ø

33. The burner as described in Claim 26 including a plurality of long-itudinal gas conduits parallel to the burner axis and radially spaced between the central conduit and the annular passage, said gas conduits being closed at the downstream end near the burner tip and connected to a gaseous feedstream at the upstream end; and a plurality of feeder lines connecting said gas conduits to said pre-mix chambers in said central pre-mix zone and/or in said annular pre-mix zone for introducing said gaseous feedstream.

34. The burner as described in Claim 33 wherein the gaseous feestream connected to said gas conduits at the upstream ends is a material selected from the group consisting of steam, free-oxygen containing gas, CO2, N2, fuel gas, a recycle portion of the product gas, and mixtures thereof.

35. The burner as described in Claim 22 or 26 wherein means are pro-vided for the heat exchange between said feedstreams within the burner and from 0 to 100 volume % of said liquid carrier is vaporized in said central and/or annular sections.

36. The burner as described in Claim 24 wherein said central bundle of parallel tubes comprises 2 to 200 tubes, and the annular bundle of parallel tubes comprises 4 to 600 tubes.

37. The burner as described in Claim 25 wherein said central bundle of helical tubes comprises 1 to 200 helical coils, and the annular bundle of helical tubes comprises 1 to 600 helical coils.

38. The burner as described in Claim 22 or 26 wherein said central conduit exit orifice has a converging portion and/or said annular exit orifice has a converging portion.

39. The burner as described in Claim 22 provided with a water-cooled face plate at the downstream tip of the burner.

40. The burner as described in Claim 39 wherein said water-cooled face-plate comprises an annular cooling chamber that encircles the tip of the burner.

41. The burner as described in Claim 22 or 26 provided with cooling coils that encircle the outside periphery of said outer conduit along its length.

42. The burner as described in Claim 22 wherein the central conduit exit orifice comprises a frusto-conical rear portion having a converging angle in the range of about 15° to 90° from the central longitudinal axis of the burner; and said rear portion may develop into a normal cylindrical front portion which terminates at the downstream face of the burner and which cylindrical front portion may have a height in the range of about 0 to 1.5 times its own diameter; and/or said annular exit orifice comprises a generat-ed converging frusto-conical shaped annular rear portion having converging angles in the range of about 15° to 90° from the central axis of the frusto-concial section, said central axis being parallel to the central longitudinal axis of the burner, and said rear portion may develop into a generated normal cylindrical annular front portion which terminates at the downstream face of the burner and which cylindrical front portion may have a height in the range of about 0 to 1.5 times its own width.

43. The burner as described in Claim 42 wherein the central conduit exit orifice and/or the annular exit orifice are made from a thermal and wear resistant material.

44. The burner described in Claim 43 wherein said cooling chamber, central conduit exit orifice and/or said annular exit orifice constitute a single piece of thermal and wear resistant material.

45. The burner as described in Claim 44 wherein said thermal and wear resistant material is tungsten carbide or silicon carbide.

46. The burner as described in Claim 22 or 26 wherein the central conduit exit orifice and/or the annular exit orifice are in the shape of or generated by the long-radius nozzle.

47. The burner as described in Claim 22 wherein separate feedstreams of a pumpable slurry of solid carbonaceous fuel selected from the group con-sisting of coal, lignite, coke from coal, char from coal, coal liquefaction residues, petroleum coke, particulate carbon soot, and solids derived from oil shale, tar sands, pitch bits of garbage, dewatered sanitary sewage, and semi-solid organic materials and a liquid carrier selected from the group consisting of water, liquid hydrocarbonaceous material, and mixtures thereof, and liquid CO2 are connected to said central and/or annular bunches of tubes;
and simultaneously separate corresponding feedstreams of a free-oxygen con-taining gas selected from the group consisting of air, oxygen-enriched air, and substantially pure oxygen are connected to the related central conduit and/or annular passage.

48. The burner as described in Claim 26 wherein separate feedstreams of a pumpable slurry of solid carbonaceous fuel selected from the group con-sisting of coal, lignite, coke from coal, char from coal, coal liquefaction residues, petroleum coke, particulate carbon soot, and solids derived from oil shale, tar sands, pitch, bits of garbage, dewatered sanitary sewage, and semi-solid organic materials and a liquid carrier selected from the group consisting of water, liquid hydrocarbonaceous material, and mixtures thereof, and liquid CO2 are connected to said central and/or annular bunches of tubes;
and simultaneously separate corresponding feedstreams of a free-oxygen con-taining gas selected from the group consisting of air, oxygen-enriched air, and substantially pure oxygen are connected to the related central conduit and/
or annular passage.

49. The burner as described in Claim 47 or 48 wherein said semi-solid organic materials are asphalt, rubber and rubber-like materials including rubber automobile tires.

50. The burner as described in Claim 47 or 48 wherein said liquid CO2 is in admixture with steam.

51. The burner as described in Claim 47 or 48 wherein said pure oxygen is in admixture with steam.

52. The burner as described in Claim 22 or 26 wherein separate feed-streams of free-oxygen containing gas are connected to said central bunch of tubes and/or said annular bunch of tubes; and simultaneously separate corres-ponding feedstreams of a pumpable slurry of solid carbonaceous fuel in a liquid carrier are connected to the related central conduit and/or annular passage.

53. The burner as described in Claim 22 or 26 wherein separate feed-streams of free-oxygen containing gas are connected to said central conduit and said annular passage; while simultaneously corresponding feedstreams of liquid hydrocarbonaceous material are connected to the related central and/or annular bunches of tubes; and simultaneously a pumpable slurry of solid car-bonaceous fuel in a liquid carrier is connected to the free bunch of said tubes, if any.

54. The burner as described in Claim 22 or 26 wherein separate feed-streams of free-oxygen containing gas are connected to said central and annular bunches of tubes; while simultaneously a corresponding feedstream of liquid hydrocarbonaceous material is connected to the related central conduit and/or annular passage; and simultaneously a pumpable slurry feedstream of solid carbonaceous fuel in a liquid carrier is connected to the free passage, if any.

55. The burner as described in Claim 22 or 26 provided with separate flow control means in each of the four feedstreams for controlling the intro-duction of said four feedstreams into the burner and their rate of flow so that either said first feedstream, third feedstream, or both may be intro-duced respectively into said corresponding central bunch of tubes, annular bunch of tubes, or both bunches of tubes at a specified flow rate, and when said feedstreams are so introduced the corresponding second feedstream, four-th feedstream, or both are simultaneously introduced respectively into said corresponding central conduit, annular passage, or both passages at a speci-fied flow rate; and upstream from each of said four flow control means said first and third or first and fourth feedstreams are connected to a feedstream of first reactant, and the corresponding second and fourth or second and third feedstreams respectively are connected to a feestream of second reactant.

56. The burner as described in Claim 22 or 26 provided with means for adjusting the throughput comprising separate flow control means in each of the four feedstreams for starting, stopping, or changing the flow rates of said first and second feedstreams simultaneously, and/or said third and fourth feedstreams simultaneously.