US2093005A - Method and means for producing gas - Google Patents

Description

Sept. 14, 1937.

H. J. CARSON METHOD AND MEANS FOR PRODUCING GAS 5 sheets-sheet 1 Original Filed April 8, 1929 Sept. 14, 1937. H. J. CARSON METHOD AND MEANS FOR PRODUCING GAS Original Filed April 8, 1929 5 Sheets-Sheet 2 www,

Wim! Sept. 14, 1937. H. J. cARsoN METHOD AND MEANS FOR PRODUCING GAS 5 Sheets-Sheet Original Filed April 8, 1929 NN l Ummm-Moz any nu.,

Patented Sept. 14, 1937 UNITED STATES EAT-ENT: OFFICE 353,576. Divided and this application March 14, 1934, Serial N0. 715,401

5 Claims.

This invention relates to the production of combustible gas in blue and carburetted water gas sets, the principal objects of the invention being to effect economies in such production by improvements in the methods and means employed.

This application is a division of my copending application 353,576 filed April 8, 1929, for Improvement in methods of and means for producing gas, now Patent 1,953,848, granted April 3, 1934, and the invention combines certain novel features with some of those disclosed in my earlier co-pending application 199,572 led June 17, 1927, now Patent 1,952,654, granted March 27, i934, and comprehends: Y

Improved methods for gasifying bituminous fuel in a water gas generator; the recovery of liquid hydrocarbons and ammonia from bituminous fuel.

When bituminous fuel is used in a generator of the usual type having the blue water gas and air blow gas oiftakes at the same level, volatile matter from the fuel is driven olf during the gas making period and is also driven off during the air blasting period. Also, in the usual up and down run method of operation in which steam for gas making is alternately admitted above and below the fuel bed, the hydrocarbons distilled from the fuel during the down run portion are passed through the hot zone of the generator fuel bed and broken down into mostly carbon and hydrogen.

With bituminous fuel, such as coal, used as generator fuel, the invention contemplates a method wherein an upper carbonizing zone and a lower incandescent or generating zone are maintained in a generator. The air blast gases from the lower zone, with or without the secondary combustion thereof, may be used for exter- 1 nally heating the upper zone or a portion of such blast gases may, when desired, be passed through the upper carbonizing zone for internally heating the fuel therein. Part or all of the hot blue water gas from the lower incandescent zone may be passed through the fuel in the upper zone for devolatilizing the fuel and any remaining portion of the blue gas drawn 01T separately for enrichment with liquid hydrocarbons. With fuel containing little or no volatile matter, such as coke,

- the invention contemplates passing part or all of the blue water gas from the lower zone through the newly charged fuel in the upper zone to thereby preheat such fuel before it descends into the lower water gas generating zone.

(o1. is-204) The improved method may also be carried out when relatively no volatile fuel is used for generator fuel, with part or all of the blue gas drawn off through the upper gas oiftake, thereby preheating the newly charged fuel before its descent lo into the lower water gas generating zone.

In carbonizing fuel in water gas generators by internal and/or external heating as above described, fuels which on heating swell, arch or hang in l0 generators and form a plastic zone through which gases are passed with difficulty if at all.

The volatile matter of bituminous fuels is of Varying composition and distillable at different temperatures. The volume and quality of the volatile matter given off varies with the temperature and time of heating.

When the volatile matter distilled off at relatively higher temperatures passes through cooler fuel, some or all of it is usually condensed on the cooler fuel. This condensate encases the lumps or particles of fuel in a liquid envelope often of a plastic nature which is not .again vaporized until the fuel passes into a zone of higher temperature. Meanwhile the coal lumps and particles contain volatile matter distillable at relatively low temperatures, which being partially or Wholly confined within the liquid envelope causes the fuel to swell.

If the volatile matter evolved from bituminous fuel as it is heated is removed from contact therewith substantially as it is formed under temperature and partial pressure conditions above the condensation point, the time required for distilling off the volatile matter at any given temperature is greatly reduced; cracking of the hydrocarbons so evolved is avoided and the condensable portion of these hydrocarbons may be recovered in liquid form. With the hydrocarbons drawn 01T as formed and cracking avoided, the 4Q lieat required for carbonization is substantially ess.

If swelling or sticking coals are preheated for atime at 900 deg. F. more or less, the swelling properties vand tendency toward the formation of a plastic zone is thereby reduced.

The invention contemplates the devolatilization ofv the fuel by the heat in the blue gas and any undecomposed steam mixed therewith passing through it at relatively higher temperatures than are obtained in usual practice when desired and supplemented by other means and methods more fully hereinafterdescribed.

The invention also contemplates preheating the coal to prevent sticking and the formation of a plastic Zone.

The invention contemplates the distillation of the fuel under controllable temperature conditions to permit the evolving and recovery of condensable hydrocarbons of varying qualities as desired, as hereinafter more fully described.

In the manufacture ,of carburetted-water gas, the invention contemplates passing apart of the water gas through the carbonizing chamber and the remaining portion in desired volume through a carburetting chamber for enrichment therein by hydrocarbon vapors fromlliquid` hydrocarbons.

The invention also contemplates the admission of steam in the lower zone of the carbonizing chamber for the formation l'of ammonia and/or blue gas with such formation yfurthered itbyy the presence of lime orV limestone when charged with the fuel for the additional purpose of iuxing the ash.

lThe invention contemplates the maintenance of optimum vtemperatures for ammonia formation in the carbonizing chamber wheny ammonia recovery isdesired.

The invention also contemplates the formation of methane in relatively large volume because of the catalytic effect in such production by any lime or limestone charged with the fuel as a fluxing agent for the ash. i

Other objects of my invention will more clearly appear from the description -and claims hereinafter following.

In the drawings forming a part of this specication, I vhave illustrated suitable apparatus, with certain indicatedrmodications under differentconditions, 'which maybe employed in the practical carrying out of my improvements in Water gas generation. In said drawings- Figui `shows a carburetted water gas plant in elevation and partly in section suitable for carrying out my improvements.

Fig. V2 is a partial plan view of the structure shown in Fig. 1.

Fig. 3 is a'n enlarged fragmentary vertical section of a oarbonizing chamber in the generator shown in Fig. 1.

Fig. 4 is a sectional view of the igenerator on the line f4-#4 4in Fig. zl, showing a restricted and elongated base and other features.Y` v 1 fFig. 5fis an: enlarged fragmentary vertical sectional view showing thedetails of construction of an air tuyre, tuyre header and air inlet valve in the lower-most air blast level of the generator y in Fig. '1.`

. of -a generator and Fig. 6 =is an'elevation of a carburetted water gas plant partly in section with modifications as hereinafter fully set forth.

Figs. vSand 7 are similar 'to Figs. 1 and 2 with the-gas superheater omitted and the carburetting and gas superheating functions combined in a carburetting-gas superheating chamber, with corresponding modifications.

Fig. 8-is an elevation of a vc'arburetted water gas plant partly in section, with generator and carburetting-gas superheating chamber as in Fig. 6, with two additional chambers each of which is used forv superheating steam and preheating air. I Fig. 9 is a plan 'view of the carburetting-gas superheating and steam superheating-air preheating rchambers-of Fig. S with some details of construction. Y Y

Fig. l0 isa view in elevation and-partly in section of a blue water gas plant consistingvmainly two regenerating chambers, each of which is used for superheating steam and preheating air as in Figs. 8 and 9 with the carburetting-gas superheating chamber omitted and corresponding modifications.

Fig. 11 is a plan view showing the steam superheating-air preheating chambers and their connections with a fragmentary plan view of the generator.

The apparatus may now be described-in detail.

In'Fig. 1 -the-gas generator I2 is shownl in section having mainly two zones, the lower zone I1 being the water gas generating Zone and containing mainly incandescent fuel. The upper zone contains a carbonizing chamber I8, which is charged with fuel, such as bituminous coal, and an ash vfluxing material, such as lim'estone, when desired through any suitable charging device as T9. Air blast inlet means are provided as `shown-at levels l20, a, 20D, and 20c. Steam inlet means are similarly shown at level 2|. 'Ihe carbonizing chamber has an annular passage around it of a relatively large area at 22 lto lower the velocity of the gases leaving the incandescent fuel and reduce vor avoid the carrying along of ne fuel particles in the gases.

The annular passage is preferably narrowed at 23 to increase the velocity of the gases and heat transfer to the carbonizing chamber. The generator wall -lining of the passageway 22 and 23 ispreferably made of heat radiating material to supply radiant heat to the 'carbonizing chamber.

The annular passageway 22 and 23 is preferably'enlarged at 24 to reduce the velocity of the gases atthis point and to further a uniform passage of the gases around the carbonizing chamber.

The gases pass from 24 into the carburetter through a conduit 25shown with a valve therein Which may be dispensed with as hereinafter described.

The wall of the carbonizing chamber I8 is preferably inadeof heat resisting metal to permit a relatively high rate of heat transfer therethrough but Ywhen secondary combustion vof the air 'blow gases is effected in 22 by air admitted as at level 20c, that portion of the chamber wall exposed lto unduly high temperatures may be made of a suitable refractory material.

I'he carbonizing chamber preferably contains an assembly T26 in the center thereof. This assembly is1 shown enlarged in Fig. 3 and is more fully described hereafter.

An inlet |21 for steam or air is shown near the bottom vof the carbonizing chamber, supplied by a vertically disposed conduit |28 passing through the assembly aforesaid and fed andsupported by a pipe 1:29. An assembly cap or valve 30 adjustable as byacable 3l for regulating the division of flow'of vgases through the assembly 26 and the fuelis shown.

The carburetter I3 hasa combustion chamber 26, vwith the usual valved oil admission-means 21 (which may be dispensed with) opening into it, also a zone of heat absorbingmaterial 28, with an oil admission Zone 29 belowwth valved oil inlets as 29a and 29h and preferably with a lower zone of heat absorbing material 30.

The bottom vof `the carburetter is in open connection with gas superheater i4, which is of the usual type and filled with heat absorbing material such as checker brick.

The gas superheater is shown with the usual stack valve 32 and a closable gas outlet 33, and

an alternate valved gas outlet'34 leads to a con- GTI denser 35 having a .gas outlet pump 31 installed therein.

The usual stack valve 32 .on the gas superheater is shown in the usual manner for use when desired. v ,Y

The topof the gas superheater opens into the steam superheating chamber l5 through a valved conduit 38 into the combustion chamber 39.

The steam superheater is lled with heat absorbing material 49 andhas a passageway 4| opening through Aa valved conduit 42 into the combustion chamber 43 of air preheating chamber I6, and similarly into a similar combustion chamber in air p11eheater|6a as indicated in Fig. 2. The air preheating chambersareflled with heat absorbing `material 44 and have an upwardly extending passageway 45 leading to stack valves 46 and 46a.

The generator is shown with a solid hearth 41 preferably slopingV toward a slag discharge opening 48 which is normally closed by any. suitable means such as fire clay.

A second slag .discharge opening 48a, is shown at a higher level for use when iron or metallic ore is charged with the fuel .as a uxing agent. The metal may be drawn o at the lower level 48 with the slag drawn off at the higher level 48a.`

The pipe 49 opening into the air inlet at level 20 indicates an admission means for gas or oxygen for mixingA with the air to eiTect combustion or raise the temperatures in the fuel bed at this level as desired for slagging the ash. This connection 49 may also be used for supplying the luxing material into the air blast.

-Another opening into the fuel bed at any suitable level, as at 50, is shown for the introduction of fluXing material as desired.

The generator is equipped with a valved gas outlet 5| in the top of the carbonizing chamber |8 for the withdrawal of the coal distillation gas and vapors and any other gases mixed therewith to such further point in the apparatus as is de- 36, with afvacuum sired.

As further shown in Figures 1 and 2:

An air supply pipe 52 is connected to valved inlets 53 and 53a. to the air preheaters. The valved preheated air outlets 54 and 54a are connected into a header 55 supplying the preheated air distributing pipe 56. The latter pipe supplies cornbustion air to the air preheating chambers through Valved inlets 51 and 51a, to the steam superheater through 58, to the carburetter through 59 and to the generator through valved inlets and air tuyre headers supplying tuyres at levels 20, 28a, 20h, 28o and air admission means |21 through valved connection 60 and pipes |29 and |28.

The air preheaters may be bypassed through a valved bypass 52a. directly into air distributing pipe 56.

Steam is supplied from a source not Vshown through a valved inlet 6| into steam superheater I5. 'I'he valved superheated steam outlet 52 opens into the superheated steam distributing pipe 63 which supplies the carburetter when desired through valved connection 64 and the genrator through valved inlet 65 .and pipes |29 and |28 leading to opening 21 and to steam tuyre openings at level 2| through a valved inlet and tuyre header as shown.

In Figure 3 an assembly is shown in a fragmentary section of the carbonizing chamber |8 with 'air or steam admission means |21 supplied by pipes |28 and |29 passing through the assembly as previously described. 1

. VThis assembly is preferably made ofza series of open cylinders or cones 66. of any desired form with the bottom of each cylinder projecting over and below `thetop of the next lower cylinder, thus forming aprotectiveskirt around the upper open end of the next lower cylinder to prevent fuel falling therein and to provide annular openings 61 for the escape of volatile matter from the fuel into the open passage-through the series of cylinders as indicated by arrows.

The assembly cap 30 is adjustable by cable 3| to regulate the division of flow of gases through the assembly and the fuel.V

Figure 4 shows the restricted and elongated section at the .level l4--4 of Figure 1 with the .uyres opening into the long sides at 61 and with the interior accessible through doors 68 and openings 69 which are normally filled with removable. refractory material. The lowermost air blast tuyre -header is indicated by 1| and the steam tuyre header at 10.

Figure 5 shows a fragmentary section of the generator wall with an air blast tuyre therein. The tuyres at each level are supplied by tuyre header pipes 1| which areA supplied by the air distributing pipe through valves 12. The tuyre nose 13 is shown projecting beyond the generator wall and water-cooled by water entering through pipe .14 and discharging through 14a.

The pipe 49 is shown inserted in the tuyre through which combustible gas or oxygen may be introduced for mixing with the air and assisting in combustion at the lowermost air blast level. Fluxing material in powdered form may also be similarly admitted into the blasting air.

In Figure 6 and the partial plan view thereof in Fig. 7 a carburetted water gas plant mainly similar to that shown in Figures 1 and 2 is shown with the gas superheating chamber of Figure l. omitted and the functions of the carburetter and gas superheater combined in one chamber as I3' with the gas outlet in its bottom leading through Valved conduit' 33k to such other point in the apparatus as desired or, when lower absolute pressures in the carburetter are desired, through valved connection 34' to condenser 35 and vacuum pump 31 and thence to such other point as is desired through outlet36.

The air and steam connections and inlet and outlet connections to the steam superheating and air preheating chambers are all substantially as shown and described in connection with Figures 1 and 2, with modifications to suit the ommission of the gas superheating chamber of Figure 1 with a steam connection 6|a for by-passing the steam superheater when desired. These connections are all disposed so the blow gases inheating these chambers will always pass downwardly and the air and steam in being preheated will always pass upwardly through the heat absorbing material. The lstack valves of Figure 1 are replaced in the construction of Figures 6 and 7 by valves |46 and |46a leading to a common stack 15.

In Figure 8 and the partial plan view thereof in Figure 9, a gas generator I2 with a valved connection 25 to carburetter-gas superheating chamber I3', both similar to the units in the previous gures, are shown with the chamber i3 connected directly to two regenerative chambers, each of which are alternately heated by the air blast gases and used for superheating steam and preheating air. Valved air supply pipe 52' and steam supply pipe 6| alternately supply air and steam to chambers I6 and Ilia through a common inlet header and valved-inlets 53v and 53a.

Y ously blasted throughout The .preheated air leavesthesefchambers through valved 'outlets '54' and 54a 'connected into lair distributing .pipe 56 Vand thence to supply combustion air to these chambers andthe generator in a similar manner as before'described. The superheated steam leaves `through outlets l62' and 62a to vdistributing pipe -63 and thence as before described. The gas 'outlet i33" leads to other apparatus or vacuum pump as before described. i

Steam and air inlets Bla and 52a' respectively are provided 'for bypassing the regenerative chambers when desired.

these that the heating :gases will pass downwardly and the air andsteam will pass upwardly through the 'heat absorbing material.

The operation of the 'apparatus is as follows, particular reference being A'had tothe apparatus illustrated in Figures l to 5:

'A fire is kindled on the generator hearth 41 and the generator is filled with fuel @preferably coke at the start), which is replenished with preferablybituminous coal thereafterthrough charging opening I9.

All -`valves are closed save stack valve 46a and valves 42a, 38, 25, 53, 54 Aand at air blast level 20. vAir is admitted through 52, 53, |5,'54,'55, 56 to air blast `level 20. rI'he gases resulting from the combustion of the fuel pass upwardly Vthrough the Afuel and passageways 22, 23 and -24 and successively through the carburetter, gas superheater,steam superheater'andthence through air preheater 'la to thestack.

As the air blasting yprogresses and the fuel bed in 'the gas generator ybecomes heated, carbon monoxide is formed in increasing volume. This carbon monoxide may be burned -by air admitted through the opening of Valves at any level as 26a, 23h, 20c,'as desired, butin starting and to heat the apparatus throughout it is preferably first burned by air ladmitted to the ycarburetter through valved inlet 59. When the carburetter is sufficiently heated or whenit is -desired to Afurther 4heat `the steam and air preheating chambers, combustion may be effected in these by air admitted through58 and 51a, as desired.

The generator vfuel bed is preferably continuthe period at level 20 and the CO content of the gas leaving the fuel bed limited by effecting combustion therewith through air admittedselectively as-desired at the higher levels, thus building -up a relatively thick hightempera'ture fuel bed with a definite limitation'cf the CO'produced, as by kthis method the fuel in the bottom `zone i-s mostlyconsumed with a reduction to ash andslag there and the heat therefrom stored inthe fuel at :higher levels with less consumptionof fuel and reduction to ash at the higherlevels.

The fuel bed may ermost -level fora certain also be blasted at the lowtime land then as the fuel'becomeshot and CO is produced-in the maximum amount desired, the blasting 'may be discontinued at this level and begun at a higher level'thus bypassing thev underlying zone of hot fuel, then again discontinued and begun at a still higher level and soon until a fuel b'ed of the desired'temperature andthickness is built up.

With the fuel bedhotand thelapparatus at the desir'ed'temperatur'ethe airblast-is cutoff and all valves save 25 areclosed. When `the gas outlet 33 is used Vand the condenser 35 and vacuum pump 31 dispensed with, the 'valve -25 may be dispensed with. `Outlet 33 communicates with a seal separator, or other apparatus, vnot shown, and is-opened.

Steam Vadmitted through Tlil passes down through passageway vIl and up through 40, where it is highly superheated, then passes through 'valved outlet 62, pipe'63, through inlet valves, ytuyre headerrand'tuyres at level 2| to the fuel bed. The steam leaveslthe tuyre openings at a relatively high velocity and through a plurality of openings so asto` penetrate the fuel bed uniformly.

The steam 'also enters the fuel 'at a sufficient distance above 'the lower zone of intensely hot fuel so as to bypass it without an appreciable cooling action on 4any =liquid vslag in the lower zone.

The freezing of the liquidslag atthe'lower level is further avoided fin supplying the steamto the fuelbed superheated at a temperature lrelatively near to or above the'freezing temperature of the slag.

The steam in passing through the relatively thick high-temperature fuel bed is decomposed with the formation'of carbonmonoxide and hydrogen lor 'blue gas. A portion `of the blue gas so formed entersthe bottom of the carbonizing chamber f8, sweeps through'the fuel in the lower portion thereof and with any volatile matter therefrom a portion'enters the bottom opening of the assembly 26. The remainder, sweeping up through the fuel, further devolatilizes it and either entering the assembly through annular openings as at A(i1 in Figure 3, or passing up through the fuel, passes out through upper offtake 5I.

The cap '30 on the assembly may be raised or lowered,'thusadjusting the flow through the fuel and the assembly 'as desired. The valve 5l is also adjustable 'to Aregulate Vthe `volume `of blue gas passing through the'carbonizing chamber.

The blue gas and any coal gasand vapors mixed therewith in passing through the cylinders of vtheassembly produces a 'vacuum effect which draws the gas from the fuel being carbonized in through the annular spaces as Ali'l 'into the stream of gas'.v

The gas and vapors are accordingly withdrawn from'the fuel substantiallylas evolved and mixing with the blue-.gas leave the'assembly through 30 and pass -out `through y5 I.

The heat for ca'rbonizing the'fuelfi's supplied by the sensible-heat of the'blue gas and any undecomposed steam passing through lit and the assembly and is supplemented by:

(a) The-'heat'in theblow gases passing around the-carbonizingV chamber with or without the secondary combustion of the blowgaseseffected-by air admitted at level 20C as desired for heating said chamber,

(b) The use of yadditional amounts of excess Y steam preferably superheated as hereinafter -described by the heat in theblow gases,

desired temperature for passes out through .oiftake .steam Y superheater, air preheater 2,093,005' (c) Passing part ofthe blow gases throughthe carbonizing chamber and using the sensible heat thereof and/or (d) Admitting air and/or oxygen in the lower portion of the carbonizing chamber through |21 for effecting secondary combustion of any blow gases passing therethrough as described above in (c).

(e) Admitting air and/,or oxygen in the lower portion of the carbonizing chamber throughv |27 for combustion and the liberation of. heat thereby. In this case the burned gases may be taken off through 5| mixedwith the distillation gases but the air or oxygen is preferably admitted during the blasting period with the distillation gas outlet restricted so the burned gases will pass out through the bottom of the carbonizing chamber into 22 and mix with the blow gases, thus preventing dilution of the distillation gases. The carbonization temperature mayy accordingly be varied and controlled by the above methods of heating. f

The hydrocarbon vapors are drawn off .substantially as formed through assembly 25 and outlet 5| with a recovery bons in liquid form whenv desired, with little or nov difficulty with the fuel arching or sticking during the carbonization process.

The remaining portion of blue gas and anyA undecomposed steam passes through 22, 23, 24, 25 into carburetter |3 and downwardlyi through the highly heated heat absorbing material 28 into oil admission zone 29. The hot blue gas mixes with oil sprayed into 29 through 29a, and 29h, and is cooled thereby. I v

The heat in the blue gas and steam and that radiated by the walls and refractorymaterial adjacent to 29 brings the of stable hydrocarbon gases- In thepassage of the gases and any uncracked oil particles through 30, and the heat absorbing v cracking is completed and the carburetted gas therein adjusted as desired so that with -valve 5|, the division of flow of gas between carbonizing chamber and carburetter is additionally regulated. Steam may be-.admitted to the car-V Aburetter when desired through valved inlet `64.

When absolute pressures lower than the .pressure in passageway 24 are desired inpthecarburetter, the valve 33 is closed or omitted with opening blanked,J the Vvalve 34 is opened and resultant gas drawn off through the condenser and vacuum pump to such further point in the;

apparatus as is desired.

:A controllable amount of air enriched ywith oxygen when desired at the ai1 blast level 2|!Y may be admitted during the gas making period `to maintain a sulciently high temperature at this level for liquefying the slag;

As the gas making period progresses, thefuel bed temperature falls and the chambers cool.-

When it is impracticable toy continue the period, all VValves except 25 are again closed and valves '46, 42, 38 are opened.

Air is then admitted to the air preheater |6a through 53a and there preheated and then passed through 54a, 55, 56 to the generator carburetter,

I6 and on through stack valve 46 as previously described.

of the condensable hydrocaroil particles to thev crackingand formation material in |4, the

33 with the valve- During vthe air blasting period the Valve 5| is adjusted torpermit the withdrawal of coal gases and vapors evolved meanwhile with the inclusion therein of a limited amount Aand preferably none of the blow gases. v 'A Steam may be admitted through valved inlet Gla, 63, 65 and 27 to blanket the entrance of blow gas into the carbonizing chamber and. for the formation of blue gas and/or ammonia and to assist in carrying 0E the coal gases and vapors through oftake 5| as previously described for the blue gas during the gas making period.

When the generator fuel bed, carburetter and regenerative chambers are sufliciently hot, the air blast is stopped and the gas making period resumed as before described. l The operation of the apparatus in Fig. 6 is carried on in a similar manner as described for Figures l. and 2, with account taken'of the omission of the gas superheater AI4 of Fig. 1.

The apparatus in Figures 8 and 9 is operated in like manner With account taken of the use of each of the two regeneratorsA l'and |6a for` superheating steam and preheating air.

In Figures 8 and 9, and assuming the apparatus to be heated and ready for continuous operation, with all valves closed excepty 52', 53', 54 and at level 20, and with 25, 42a^and 46a" open, air passes through and is preheated in I6 thence through 54 and 55" to the generator, carburetting-superheating chamber, regenerator |6a' and thence to stack through 46a". This blasting is controlled and varied at the different generator levels and in` the other chambers as previously described. When 4the desired temperature is reached in the generator and other chambers, the air blast is discontinued yand all valves except 25 are closed. Steam is now admitted *to regenerator |6a' through 6| and 53a' and superheated therein, passes through 62a into distributing pipe 63' for use as previously described, the gas outlet 33" leading to vacuum pump or other apparatus' as before described.

`when the fuel bed'andapparatus is cooled to such an extent that it is no longer practicable to continue thev gas making period, steaming is discontinued, all' valves are'v closed except 25. Valves 52', 53a', 54a and at level 2|] in the generatorand also 42', 46" are open.' The air passes through and is preheatedin |6af, andthen passes therefrom to level 2|] in the generator fuel bed. 'I'he gases therefrom pass through 25 carburetter I3', 42', I6', 46" and out throughv stack l5.l Air blasting is continued by varying the air blasting as at 20a, 20h, 20c and 21 by opening and controllingthe valves at vthese levels as desired andy also for effecting secondary combustion in the fore described, are heated to the desired temperature, when steaming is again resumed with the steam Asuperheated vin regenerator I6 as previously described.

Each regenerating chamber is accordingly heated by the blast gases 4and used for preheatin g air during alternate blasting periods and each is alternately used for superheating steam during alternate gas'making periods.

The regenerators I6 and ISa' preferably contain preheated air offtake zones as 44a lwith valved outlet 54" for connection into preheated air distributing pipe 5 6 to avoid cooling the upper mass of heat absorbing material b y the air so the heat therein is conserved for superheating the steam to a'relatively higher temperature.

In- Figuresl and. 11 a plantisshownsimilar to that in Figures 8 and 91with the4 generator partly in section and having an additional valved gas outlet Sla to permit the withdrawal of gas from the annular space 24 and with the carburettingA gas superheating chamberl and corresponding changes.

Air and steam admission to the generator is carried on as described for Figures 8 and 9. A

I3. omitted ,portion or all or none of the blue gas maybe withdrawn through the carbonizing chamber and outlet 5l with the coal gas and vapors mixed therewith, any remaining portion being discharged through gas outlet 51a,

The generator in all the combinations may be Y operated as described for Figure 1 and the two regenerators shown in Figures 8, 9, 10 and 1l in which each is used for preheating air and superheating steam may be used with the plants shown in Figures 1, 2, 6 and 7 instead of the separate steam superheater I5 and air preheaters I5 and I6a.

The separate steam superheater andv air preheater as shownfin Figures 1, 2, 6 and? arefpreferably used when the highest practicable deg-ree of superheat in the steam isV` desired and when air is admitted to-'the generator0 during the gas` making period as at levelV 20.. The steam superheating chamber has a blanketing effect as the steamentering this chamber may be at a higher pressure than the air in the airA preheating cham-` bers. andprevents any air leaking. through the valves ask 112Y and 42a, entering the carburetting chamber and mixing with the gas therein.

With the use-of two regeneratorseachfor su.- perheating steam and preheating air-, a higher degree of superheat may be obtainedin the steam by providing a sufficiently large and long passage of. heat absorbing. material to permit taking the preheatedair from an intermediate point in each chamber as 5,4 in Figure 8, thus avoiding the coolingaction of theair onthe hottest portion of the heat absorbing material M' and conserving the heat therein for superheatingthe steam to a relatively higher temperature.

The economies and advantages ofthe different features ofI my invention will be apparent tothose skilled inthe art from the Vforegoing descriptionl and may be briefly outlined as follows.

The carbonizing chamber andthe assembly therein are so constructed and used that the presentvusualV difcultiesdue to the stickingant hanging ofk the fuel are-overcome andthe-coal 'I-'he different. features are all combined toA provide. methods. for the production. of gas at relatively high rates in apparatus of.l a. given size with a minimumvconsumption of fuel,. air, .steam and time.

Having described my invention, I claims.

1. The improvement. in. the manufacture of water gas which, when carriedout inV agenerator .havingl a lower incandescent fuelk zone and. an

upperV carbonizing fuel zone -and an apertured Y distillation.. assembly'- located in the. upper. portion of the--carbonizing zone, includes:` blasting the lower zone of fuel to incandescence with air and withdrawing the resultant products from the upperv portion of said zone; alternately with the air blasting, generating water gas by admitting. .A

steam to said lower zone of fuel; devolatilizing the fuel in the `lower portion of the carbonizing zone by passing steam upwardly therethrough during air blasting periods and also by passing water gas upwardly therethrough during thegas runs; and conducting the steam and the water gas, each admixed with gas liberatedfrom the fuel, upwardly through said apertured. assembly and simultaneously drawing'into the admixed steam and gas, vapors and gases distilled from the fuel in the upper portion of the carbonizing zone.

2. The improvementin the method of manufacturing water gas from bituminous fuel' in a incandescent fuel:`-

generator having a lower chamber and an upper carbonizing chamber in open and direct communication with each other and wherein means having a vertical central" passage therethrough and vents in the sides thereof,` isdisposed withinthe carbonizing chamber with the lower portion of said. means positioned a substantial distance above the bottom' of the carbonizing chamber, which consists in;- alternately air and steam blasting the incan' descent fuel to generate water gas and passing the hot water gas from the incandescent fuel upwardly through thatiportion of the fuelA in the lower portion ofthe carbonizing chamber located below said means and thence. into said means both directly into the bottom thereof and valso through the sides thereof and' withdrawing the hot water gas admixed with products of distillation from the top of said means without the water gas, contacting the cooler fuel in the upfperV portion ofv said carbonizing chamber. v

3. The` improvement in the method of manu facturing water gas from bituminous fuel in a generator having a lower incandescent j fuel chamber andl an upper carbonizing chamber in direct communication with each other and wherein stationary means having a vertical central passage therethrough and vents in the sides thereof, is disposed within the carbonizing chamber with the lower portion of said means posi- 'j tioned above 4the' bottom of the carbonizing chamber and which consists in'.4 alternately air and steam blasting the incandescent fuel to generate water gas and passing hot water gas from the incandescent fuel directly to and upwardly' through the fuel in the lower portion of the carbonizing zone and thence into'said means through the bottom and side openings thereof and', during the alternate air blasting periods,

passing a portion of the air blast gases similarly` through the fuel in said lower portion of the carbonizing chamber and thenceinto said means and withdrawing both the hot water gas and blast gas admixed with the products of distillation from the top of said Vmeans without thev water gas and blast gas contacting the cooler fuelin the upper portion of the carbonizing chamber.l

4. In the manufacture of water gas from carbonaceous fuel in a generator wherein the fuel descends successively through a carbonizing chamber and an incandescent fuel chamber subjected to alternate up.blasting of air and steam for the generation of water gas, the improvement which consists in: confining thevfuel in its passage through the carbonizing zone to a column of approximately annular form; during the air-blasting periods, heating said fuel column by passing blast gases vertically upward along one of the sides of said fuel column but out of contact therewith; and, during the steam-blasting periods, passing generated water gas into the lower portion of said fuel column and upwardly thereof on the opposite side of said fuel column to effect distillation thereof and, simultaneously with said upward passage of the water gas, withdrawing laterally from said fuel column in the carbonizing chamber, the evolved products of distillation progressively at vertically spaced intervals along that side of said fuel column along which the water gas is passed.

5. In the manufacture of water gas from bituminous fuel in a generator wherein the fuel descends first through a carbonizing zone and thence into an incandescent zone wherein the fuel is alternately up-blasted with air and steam to produce water gas, the improvement which consists in: maintaining the fuel, in its passage through the carbonizing zone, between perforate and imperforate confining walls in a column of substantially annular form of graduated increasing cross section from top to bottom thereof; during the air-blast periods, passing blast gas upwardly of said column of fuel alongside the imperforate confining wall thereof and, during the steam periods, passing generated water gas into the lower portion of said fuel column and upwardly alongside the perforate confining Wall thereof and creating a partial vacuum in said fuel column and thereby Withdrawing laterally and progressively at points along the perforate Wall, the products of distillation evolved in said fuel column.

HIRAM J. CARSON.

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