CA1078613A

CA1078613A - Gasifying apparatus

Info

Publication number: CA1078613A
Application number: CA228,058A
Authority: CA
Inventors: Reinhard Waldhofer
Original assignee: Shell Internationale Research Maatschappij BV
Current assignee: Shell Internationale Research Maatschappij BV
Priority date: 1974-05-30
Filing date: 1975-05-29
Publication date: 1980-06-03
Also published as: IN143291B; IE42149B1; JPS5817519B2; CS181294B2; GB1501284A; FR2273232B1; DD119266A5; FR2273232A1; AU8164275A; IT1037718B; DE2425962C3; BE829733A; DK237875A; IE42149L; JPS515302A; NL7505661A; DE2425962A1; DE2425962B2; ZA752996B; BR7503392A

Abstract

ABSTRACT OF THE DISCLOSURE
The apparatus has an outer pressure jacket in which a unitary pipe cage is received to define a clearance therewith. The pipe cage bounds a gasifying chamber and is insertable into and re-movable from the pressure jacket as a unit. A cooling arrangement is provided for water-cooling the cage, and a thermally insulating layer is received in the clearance between the cage and the jacket.

Description

~ f~ f The present invention relates generally to a gasifying apparatus, and more particularly to an apparatus for gasifying flnely divided fuels.
It is known to gasify finely divided solid fuels floating in oxygen-containing gas and at high pressure, parti-cularly at a pressure of between substantially 15 and 80 atmos-pheres. It is also known to do the same with liquid fuels which are finely divided, and the invention is applicable to both types of fuels~
~he prior art apparatuses fulfill their intended pur-pose, but it has been found that further advances in the state of this art are desirable in order to arrive at a more economic operation, and to reduce repairs and, to the extent that repairs do occur, to make the components of the apparatus more readily accessible.
Accordingly, it is an object of the present invention to provide an improved apparatus for producing gas from finely divided fuels.
More particularly, it is an object of the present invention to provide such an improved apparatus in which the heat which is liberated during the ga.sifying process is already in part used in the region of the gasifying apparatus itself.
; Another object of the invention is to provide such a gasifying apparatus wherein the elements which are required to be repaired and/or inspectef~ are readily accessible.
In keeping with these objects, and with others which will become apparent hereafter, the invention resides in an apparatus for the gasification of finely divided fuels in - suspension by reaction with oxygen-containing gases at elevated pressure. The apparatus includes a gasification chamber defined by a water tube wall structure arranged in a dismantlable outer pxessure shell so as to be removable as a unit therefrom.

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Insulation layers are provided, comprising an inner layer separated from an outer layer by an annular gap provided between the pressure shell and the tube wall structure. The tube wall structure may be internally lined with refractory tamping compound. The bottom end of the pressure shell and an adjoining slag discharge shaft may be respectively removable in the downward direction fxom the remainder of the apparatus. The apparatus may have a slag outlet from the gasification chamber ~ which opens into a slag discharge shaft of larger diameter than 10 the outlet and which may have a sharp dripper edge wi-thin the shaft.
The novel features which are considered as charac-~ teristic for the invention are set forth in particular in the ; appended claims. The invention itself, however, both as to its construction and its method of operation, together with addi-tional objects and advantages thereof, will be best understood ' from the following description of specific embodiments when read in connection with the accompanying drawing.
FIG~ 1 is a vertical section through a gasifying apparatus which, in the illustrated embodiment, is for gasify-ing the coal dust; -FIG. la is a fragmentary sectioned detail view of FIG. 1, and FIG~ 2 is a section taken on line II-II of FIG. 1.
Referring now to the drawing in detail it will be seen that in FIGS. 1 and 2 reference numeral L identifies the outer pressure jacket 1 of the gasifying apparatus. Reference numeral

2 identifies a liner or cage of pipes which is insertable into and removable from the pressure jacket 1 in toto. The cage 2 bounds the actual gasifying chamber 3; it is composed of a plurality of tubes 5 which are welded to one another and which are connected to an upper annular conduit 5 and a lower annular ~3 ~ - 3 -`~ 3 conduit 6, respectively. Water is supplied to the lower annular conduit 6 from an external annular conduit 7 via gravity tubes 8.
The water circulates through the pipes of the cage 2 to cool the same, becomes heated, and leaves from the upper annular conduit 5 to travel to an outer annular conduit 9 from where it is removed. The cage 2 is protected against direct impingement by flames at its inner side facing the chamber 3 by a refractory substance 10 which can be tamped in place.

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According -to the inven-tion, there is provided between the cage 2 and the pressure jacket 1 an insulating layer which is to prevent the pressure jacket 1 from becoming heated to undesir-ably high temperatures. In the present invention -the insulating - :
layer is composed of a first layer 11 of insulating stones or an-other suitable insulating material, which is in engagement with the pressure jacket 1, which is in engagement wi-th the pressure jacket 1, and inwardly thereof is a front layer of insulating filler mater-ial 12. The two layers 11 and 12 form with one another at their interface a gap 13 which may be very narrow. An inert gas can be admitted into this gap, preferably nitrogen, via the inlet 14 and is removed via the outlet 15.
In the illustrated embodiment the apparatus comprises ; four water-cooled burners 16 which receive a mixture of coal dust and oxygen through respec-tive supply lines 17 (one shown). In the `~
illustrated embodiment the burners 16 are horizontally arranged and, ; as FIG. 2 shows, are so arranged as to extend tangentially to an imaginary center circle of the apparatus which may have a diameter -of 300 millimeters. The diameter is of course exemplary only.
The gases produced during gasi~ication leave the chamber

3 through the upper gas outlet 18 which in the illustrated embodi-. . , .
ment is of conical configuration and which is water cooled or else constructed as a steam generator, for which purpose a water inlet 19 and an outlet Z0 may be provided. A plurality of water nozzles 33 communicate with the gas outlet 18 so that water can be sprayed in-to the outlet in order to obtain a rapid cooling (quenching) of the gases produced in the chamber 3, and thus to assure a rapid solidification of possible tacky slag components that might be car-ried along in the stream of gases leaving through the outlet 18.
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The liquid slag which is generated during the gasifica- ----' ~

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8~3 tion flows through -the outlet 21 at the bottom of the chamber 3.
This outlet 21 is bounded by a sharp edge 22 (compare FIG. la) from which is drips off. The purpose of making the edge 22 sharp, rath-er than rounded or beveled, is to assure -that the liquid slag will actually drip off it, rather than forming deposits on it. The slag then falls into a water bath 24 which is accommodated in a slag re-moval condui-t 23 -that is flanged to the bottom wall 31 of the pres-sure jacket 1 at 38; entry into the water ba-th 24 causes the liquid slag to become granulated and it can then be broken up further and removed through an appropriate outlet, the device for breaking up - and the outlet being no illustrated because they are known per se ~ -in the art.
The conduit 23 is also water cooled or else can be con-structed as a steam generator, and is provided for this purpose with ' a wa-ter inlet 25 and a water outlet 26, Water for the water bath ~
24 is supplied through a water inlet 27 and water is removed from -the water bath through the outlet 28. The slag removal conduit 23 is provided with a water-cooled manhole 29 which is provided with ` a temperature and pressure measuring arrangement 31, e.g. a nipple through which such àn arrangement can be inserted or removed from the exterior. A similar manhole 30 communicates wi-th the chamber 3 and also has such a nipple 31 provided for it. Of course, in normal operation the two manholes 29 and 30 are closed, and they will be opened only when the apparatus is shut down and access to its interior is required. An oxygen lance 32 is provided which is directed against the outlet opneing 21 in order to cause melting- -off of any slage deposits tha-t might form at or about the opening 21. A pilot burner 40 is provided which is shown in FIG. 2.
The presence of the gap 13 between the layers 11 and 12, `
30 a further horizontal gap 34 between the upper and lower parts of -~

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'': ' 6~3 the inner lining 12, and a further gap 36 which surrounds the out-let 35, makes it possible --after removing the burners 16-- to lift the entire cage 2 upwardly out of the pressure jacket 1 without any difficulties. If necessary, the slag conduit 23 can also be removed downwardly from -the bottom wall 37 after the flange connection 38 is disengaged, and the bottom wall 37 itself can be removed after the connection of its flange 39 to the circumferential wall of the jacket 1 is disengaged.
The purpose of the gaps 13 and 34 is to make it possible to surround the cage 2 with the insulating layer 12 with a pro-tec-tive "curtain" of inert gas, in order to provide a more effective protection of the pressure jacket 1 against the high temperatures in -the chamber 3. Controlled admission of the inert gas is needed to assure that the condensation point of the inert gases at the in-ner wall of the pressure jacket 1 is not reached, because otherwise the iner-t gas, which can partially penetrate the porous insulating ; layer 11, might cause condensation at the inner wall of the pres-sure jacket 1; this would lead to corrosion. The inert gas is par-tially removed through -the outlet 15, and partially it enters the chamber 3 due to gaps or the like that might be present.
A loclc has been illustrated in FIG. 1 which is below the ~, water bath 24 and through which the slag is periodically removed.
The inlet 27 for admission of water to the water bath 24 has been shown oval in this embodiment, because i-t is advantageously construct-` ed in a diffusor-like manner in order to prevent -turbulence from he-ing caused in the water ba-th as the incoming water enters -the same. ;
One or both of the manholes may be filled (when closed) -: .
by water-cooled bodies having an intermediate struc-ture as shown `~
in FIG. 1, which together with the cooling water inlet and outlet -;
assures water circulation in the manhole in order to cool ito The ' ' ., :: .,, , ~ . . :.

~L~78~L3 entire water-cooled body can be removed outwardly, together with the outer flange, to afford access to the manhole.
The nipples 31 are preferably provided with pressure-measuring gauges, and a temperature sensing device can be inserted through them into the interior of the apparatus, to measure the ; temperature, whereupon it is again removed in order to protect it from damage resulting from the high temperature in the chamber 3.
The purpose of the pilot burner 40 is to heat the chamber - `
3 and the surrounding wall initally, before the apparatus is placed in operation. Subsequently, the stable flame of the pilot burner 40 assures a proper ignition of the burners 16.
The purpose of the outlet 35 is to remove water from the entire system of pipes, i.e. the cage 2 with the associated pipes.
This is necessary if the cage is to be removed for inspection and/or repair.
With respect to the burners 16, it should be noted that -` they need not be tangential to the aforementioned imaginary circule~
just as the 300 millimeter diameter mentioned for this circle is `;
only exemplary. The burners could also be so arranged that they are located pairwise opposite one another, and are coaxial and lo-cated in common planes, or in different planes.
The layer 10 is of a material which is thermally insulat-.
ed and which protects the cage 2 against damage ~rom the high temp-erature prevailing in the chamber 3. The layers 11 and 12 have only a thermally insula-ting function. All refractory materials which are known for these purposes can be employed.
It will be understood that each of the elements describ-ed above, or two or more together, may also find a useful applica-tion in other types of constructions differing from the types de- `
scribed above.
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~ 86~3 While -the invention has been illustrated and described as embodied in a gasifying apparatus, it is not intended -to be lim-ited to the details shown, since various modi~ications and structur-al changes may be made without departing in any way ~rom the spirit o~ the present invention.

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Claims

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

1. Apparatus for the gasification of finely-divided fuels in suspension by reaction with oxygen-containing gases at elevated pressure, characterized by a gasification chamber defined by a water tube wall structure arranged in a dismantl-able outer pressure shell so as to be removable as a unit therefrom, insulation layers comprising an inner layer separated from an outer layer by an annular gap being provided between the pressure shell and the tube wall structure.

2. Apparatus according to claim 1, wherein said tube wall structure is internally lined with refractory tamping compound.

3. Apparatus according to claim 1, wherein the bottom end of said pressure shell and an adjoining slag discharge shaft are respectively removable in the downward direction from the remainder of the apparatus.

4. Apparatus according to claim 1, having a slag outlet from the gasification chamber, said outlet opening into a slag discharge shaft of larger diameter than said outlet and the latter having a sharp dripper edge within said shaft.