US1937580A - Gas making apparatus - Google Patents

Description

Dec. 5, 1933. H 0' LOEBELL GAS MAKING APPARATUS Original Filed May 23, 1923 2 Sheets-Sheet 1 BY g a INVENTOR: HENRY O. LOEBELL ATTORNEY Dec. 5, 1933. H O LOEBELL 1,937,580

GAS MAKING APPARATUS Original Filed May 23', 1923 2 Sheets-Sheet 2 INVENTOR HENRY O. LOEBELL BY 2 ATTORNEY l atented Dec. 5,;

1,937,580 GAS MAKING APPARATUs 1 Henry 0 Loebell, Malba, N. Y.,.assignor to p .HenryL. Doherty, New York, N. Y.

Original application May 23, 1923, "Serial No.

640,828. Divided and this application May"23,-

making gas for industr 1931. January 31, 1924 Serial No. 539,600, and in GreatBritain '1 Claims. (01. 202- 88) This invention relates to the manufacture of fuel gas, and more particularly to a method of ial purposes by the complete gasiflcation of coal. r

The gas which is now being commonly burned for industrial heating purposes is known as a producer gas which has a comparatively low calorific value. This gas is manufactured by a process of burning coal wherein inert materials such as nitrogen of the air used and carbon dioxide formed by combustion of carbon with the air remain in the gas so that to %of the gas is inert material; Producer gas has a limited use for industrial heating purposes, because it has a low flame temperature,

a low calorific value and a slow flame propagation. Some heating processes require comparati tures and an attempt a blue water gas for this purpose.

vely high flame temperahas been made to make The so called blue gas has a comparatively high flametemperature and a compar inert materials, but the Water gas is'very high water gas from a'ton small as compared with the amount of producer gas which can be made One object of the present invention is to pro vide a method of manufacturing an industrial atively low percentage of cost to manufacture blue and the yield of the blue of coal is comparatively from atom of coal.

fuel gas which has a comparatively high flame temperature, a rapid flame propagation, and a calorific value which'adapts it for practically all industrial heating purposes.

Another object of th a method of making e invention is to provide industrial gas by which of gas being made.

' With these and other view, the invention con sists the improved' g'as making process hereinafter described and specifically defined in the claims.

The various features of the invention are illustrated in the which ccompanying drawings, in

Fig. 1 is a viewin vertical section with parts in elevation of a gas generator embodying the preferred form of the 'Fig. 2 is a top plan view of the generator shownin'Fig. 1; I Fig. 3 is a vertical se invention ctional view of the waste generator; and

orator shaft.

objects .and featuresin' heat boiler used with the generator, the section I being'taken on the line 3,3 (if-Fig. 2; p

Fig. 4 is a horizontal sectional view :taken on the line 4-4 of Fig; 5, illustrating-"the mechanism for removing coke'from the bottom of the 30 Fig. 5 is a vertical sectional viewtaken onthe line 55 of Fig. 4 to illustrate the coke' discharging mechanism. The method of making fuel gas embodying the preferred form of the invention maybe carried out in the apparatus illustrated in the' drawings substantially as follows: Fuel to be carbonized, which is preferably a coking grade of bituminous coal in mixture with coke,-is-p1aced in a hopper 10 and is intermittently introduced into the upperpart of a generator-shaft 12 by'means of a pocket 14 and intermittently operated valves 16 and 18. When the valve 16 is moved downwardly,

the pocket 14 will be filled with'coal. At this 2 time the valve 18 is closed. Thereupon the valve 16 will be closed and the valvelS will be opened to allow the fuel to pass into the top of the gen- The fuel discharging from the pocket 14; passes around a central'gas off-take 20 and is distributed into the top of an upright column of fuel supportedin the shaft 12.- The upper portion of the fuel column or approximately the portion above the lower end of the gas offtake 20, comprises a coal carbonizing zone." The 35 portion of the fuel column below'the bottom of the off-take 20- and extending downwardly a short distance below an offset portion 22 in the shaft 12 constitutes a blast zone in which the fuel is maintained at a comparatively high temperature by partial combustionthereof. 1 The portion of the fuel columnfro'm the bottom of the blast zone to the bottom of the column is a cooling or quenching zone in which the unburned carbonized fuel and ashes are quenched before being removed from the generator. The unburned carbonized fuel is continuously dis;

'ch'arged from the bottom of the column and con- 7 tinuously moves downwardly through the shaft.

' The gas is made'byseveral' distinct reactions whichtake place between the fuel'and the air .and steam used for making the gas. The first reaction is an'eXOtheImic reaction which takes place when-air is used to-burn carbon of the 1 5 of the fuel bed and. the'carbon dioxide which is Y' at aitime.

.is mounted inthe'inletfiue 4a in a position to bottom of the central ofif-take 20.

formed by the combustion of air, in accordance with the following equation, which is endo thermic:

C+CO2=2CO-5900 B. t. u.

A third reactiontakes place between carbon of 'the fuel bed and steam which is introduced at the fuel bed, the reaction being endothermic, as

follows:

A fourth reaction is that which takes place'when air and steam is heated in a pair of.preheaterswhich are so arranged that one preheater is used for preheating the mixture, while the other preheater is being heated by burning gas therein. When one preheaterhas been cooled to the minimum working temperature which is desirable,- by

passing steam and air through it, the circulation of the steam and air mixture is stopped and then started in the-other preheater which was being heated; during the time when the first preheater was used for heating the mixture of steam and air. To accomplish this air is introduced into one of the preheaters VZ lthrough a pipe 26, and steam is supplied to, the pipe 26 through a pipe 28. Thesteamand air mixture enters the top of an exhaust section 30 of the preheater, passes downwardly through a checker brick filling in the sectionf30, then through an opening 32 into the bottom of the main section of the preheater 24,

randthencepasses upwardly through a checker brick fillingin the main section, In passing through the two sections of the preheater the steam, and air mixture becomes highly heated and it then flows through a blast neck 34 into a passage 36 surrounding the blast portion of the fuel column; From the passage 36 the mixture of steamand air enters the fuel column, a portion of; it'forcin'g its way through the column to the In passing through the fuel column the fuelgas'is made principally by the first three reactions outlined ,above, andthe hot gas formed passes: upwardly through the off-take in contact with a series of superheating tubes 38, wherein water, vapor or steam to be used forthe gas making operation is superheated before it is introduced through the .pipes'28'into sections 30 of preheaters24. After passing through the off-take 20 the gasflows "throughoutlets 40, Figs. 1 and 2, to a conduit 42 which conducts it to, inlet flues 44 of waste heat boilers 46 and 8. In the waste heat boilers the hot. gaspasses upwardly through a series of tubes 50, Fig. 3, to a passage 52 at the top of ,the boiler, then downwardly through tubes 54 to an outlet fine 56, whence the gaspasses through a conduit58 to a cooler of suitable construction, whereby the gas may be cooled and be 'ready 'to pass to the place of consumptionor to the usual holder (not shown).

In normal operation of the gas generator the hot-'g'as carried oif'through the off-take 20 is used to' heat the boilers 46 and 48 simultaneously.

If, however, one of the boilers needs to be cleaned or. if one of the boilersgets'out of-order, all of the gas may be passed through one of the boilers Io-accomplish this a valve 60, Fig. 1,

which are usually formed in coal gas.

be moved into a valve seat 62 positioned at the bottom of the conduit 42. The valve is mountthe left of Fig. 1, is used for preheating the air and steam mixture, the preheater 24, shown at the right, is being heated by burning gas therein. At thistirne the preheater 24 at the right of Fig.

1 is cut off from the shaft 12 by means of a valve '76, and a portion of the gas from the conduit 58 is conducted through a pipe 78 and valve 80-into the top of the main section of the preheater. At the same time air is introduced through an inlet 82, and the mixture'of burning gas and air passes downwardly through the main section of the preheater, thenaupwardly through the exhaust section 30 of the preheater, and; exhausts through an outlet 84.. A cover '86. on the outlet-84 is open during the heating operationof the preheater, and the air and steam inlet pipes 26 and 28are closed respectively by suitable valves 85 and 87. (Fig. 1) y The central off-take 20. which functions as a heat exchange means is supported on the top' of the shaft '12 by the outlet pipes 40*andalso by a series of braces 88 which are attached to the frame 90 of the generator. the off-take consists of the superheating tubes 38 which are connected between an inlet manifold 92 at the top, Figs. 1 and 2, a distributing manifold 94 at the bottom, and an outlet manifold 96 at the top. The steam to be superheated, is introduced into the inlet manifold 92v by-means of a pipe which connects with a steam header 9'2, mounted between the waste heat boilers 46 and i8. Suitable valves 98 and 100are placed in the header 97 to control the flow of steam from the boilers. The steam flows fromthe inlet header 92 downwardly through tubes 38 to the header 9 irand then upwardly through tubes to the header 96 and out through a pipe 102, which preferably is connected with the sections 30' of the preheaters 24; Water .is introduced into the waste heat boilers through inlet pipesil04. The waste heat. boilers will abstract the larger portion of the heat from the fuel gas and this heat will normally produce a sufficient amount, of steam to take care of the requirements'of the gas making operation. I-Iowever,- the wasteheat boilers may be. supplemented with other steam boilers in makingup the required amount of steam, so that onset the Waste heat boilers may be shut down-for any desired purpose.

By the time the fuel has moved downwardly throughthe'carbonizing zone and reached the blast zone there is substantially no volatilemae The inner. lining of terial therein and therefore the gas which passes upwardly, through the offtake 20 contains. substantially no tar, ammonia, or other products Accordingly, the gas which leaves the waste heat .boilers does not require any special purification.

' The volatile material of the coal and other valuable icy-products such as tars, oils andammoniaare removed from the coal by low tem- This small amount of gascontaining the byproducts' passes into a peripheral outlet 106-at the top of the shaft; and flows throughra con- 'duit 108 which conducts it to the usual purification and treating equipment (not shown); In this equipment the valuable by-products are removed and the purified'gas maythen be'mixed with the gas passingv through the outlet pipe 58. By this means substantially all of the valuable by products of thelcoal may be continuously removed and the coal converted into a coke'or car'- bonized fuel which is very well suited for 1a blue water gas reaction. The gas containing thebyproducts is comparatively small in volume, compared with the entire gas output of the producer,

and therefore the by-products may be recovered by treating a comparatively'small amount of gas. .Althoughnthe temperatures used'in the'blast zone 'for .making gas are comparatively high,

these temperatures are not 'sufliciently high to slag. or clinker'the fuel,-and thereforeacomparatively large amount of the. unburned fuel passes .down to the bottom of the fuel'columnpi This fuel is principally coke .or-carbonized fuel and must be quenched to prevent destruction of the bottom of theshaft 12. To'thisend .the unburned carbonized fuel and ash is supported in the bottom of the shaft upona series of hoppers Y 110, Figs. 1, 4 and 5. The hoppers are preferably made of a steel construction and. are protected by refractory masonry 1ining. The hoppers,

seven in number, consist -'of' six peripheral hopv 116, which are spacedfrom, but directly .un- :der the openings. The-platforms 116*are arranged to be given a. reciprocatingmotionfby means of wateroperated engines 1-18 to'discharge the carbonized fuel from the platforms intosa hopper 120 immediately below the hoppers 110.

'To cool the. carbonized fuel passing down'ito the hoppers 110a water or steam pipe 122 is positionedbelow the hoppers and: has an outlet 124 extending into each of the openings 112 .and 114 by which water or steam maybe directed into the carbonized fuel to quench and cool it; The water or steam introduced intothe hotcarbon- ,ized fuel passes upwardly through theifuel 001-.

umn in the form of vapor, thus acting to eifec- .tively cool the carbonized fuel in its upward passage.

action with the carbonized fuel of "the-fuel column, so that it is utilized'in makinggas in the same way that the steam .enteringthe fuel-1column through the preheateris used.

The carbonized fuel discharged from the hoppers 110 to the hopper 120 passes th'roughiaw series of outlets 126 on the bottom of. the hopper 12(land "-is collected in: a chamber 128 atthe'bottom of'- the shaft. Periodically'a door 130 at the bottom :of the chamber 128- is openedand the carbonized fuel accumulated thereinmay'be drawn out; At the time the door 130'is opened to withdraw carbonized fuel from the chamber 128, doors 132 are moved into position to cover the outlets126xby- V V .7 I

i In other words,;.by preheating the= .steam, air, ;and carb0n,-;,the nitrogen content is'reduce'd from.

meansof operating shafts 134th'atexte'nd tothe outside of; the gas generating shaft 12. When the onstrated as follows;

.stantially 6263 B. t; u. may be made.

door 130 is closedthedoors 132 are opened to "permit the carbonized: fuel to pass from the hopper 120 to' the chamber 128 and thus the carbonized fuel and ashes may be withdrawn from thebottom of theshaft without allo'wing gas to escape. To assistin moving the carbon.-

iz'e'd fuel through the hopper 120 a series of pokers: 136 passthrough the chamber-128 and the hopper 120, by which the carbonized fuel may be barred J and 'brokenup while it is passing down to the openings 126' of the hopper-120: l

a An important feature of the present invention consists in giving a high degree of preheat tothe mixture of air and steam being used for making gas whereby. the inert material from the. coming the steam and airthegas can be made with a lower percentage "of air in proportion to the amount of steam used, and thus cut down'the amount of inerts in the gas.

.Inthe exothermic reaction between carbon and air' when bothtthe carbon and'the air start'cold,

the following reaction takes place;

If, however; the air-is preheated to 2000f, F. and

the'carbon is preheated to 1500 F. a gain of sub- "In the endothermic reaction between carbon This maybe demand. water vapcr on the basis that carbon is cold 'fcigii oecozafzia -imo B. t. u.

'imate1y i125 B..-t.'u. may be made.

If; however, the-steam is preheated to 2000 F. and 1 the carbon is heated to 1500f F.,'a'gain.of approx- 1 l '5 The endothermic reaction between carbonand carbon-dioxide, assuming-that both arefcold, is

substantially. as follows; l

o+coiz =zoo tedoa t. u. If, however, the C92 is preheated to 2000-F. and

' the carbon is preheated to 900 Ra gain of'substantially2725'B't. 11. maybe effected: .Assuniv ing that theabove reactions take, place when the constituents'are cold, as outlined above, a thermal heat balance may be obtainedwhen the endothermic reaction between carbon and water vapor-and the carb'onand carbon dioxide constithe analysis of theg'as would be in percentages By the time the steam'reaches the blast zone it is highlypreheated and enters'into re-.

by volume.

, v 002 252 i-i2{,=22.s N2=52.'0, V Bitiuivalue of gas percubic foot,='75.5.-

However; whenvassuming thatthe reactions take place, when the steamand air-are heatedto 2000" 'F. and the carbon is heatedto 1500 F.- a} thermal .heatbalance will take place when=39% of the constituents enter :into exothermic reactions, and

61% of the constituents enter into an endotherftutes 45% of the reaction, and the exothermic I V 52 to- 39.7%, the inerts are reduced from 77.2 to

66.9% and the calorific values increased from .74'.5 to 108 B. t. u. per cubic foot. In the'presentprocess the degree of preheat depends strictly upon the .nature of the coal which is being treated,-and,

, preferably. will vary from 1200 F. to 2200" F. -By

i of the shaft, a centrally-disposedgas offtake in the shaft with its inlet adjacentthe'vertical mid- .water. gas.

preheating, a gas having a calorific valueof; from 200-to 225 B. t. u. per cubicfoot may be produced whichhas'most of the advantageous-features of The products of combustion of this gas will have a calorific value ranging from.80-- B. t. u. per cubic feeteven when no preheat is imparted to the blast air.

A typical analysis of a gas made by theipresent process is substantially as-follows:

In accordance with the character of the coal being treated a gas maybe madewhich willhave a total. amount of inerts of from 45 to 52 per cent. Furthermore by the low temperature carboniz'ation applicant is able to gain asubs'tantial'amount in volume of methane produced and also gains considerably in the amount of carbon monoxide is therefore suitable for practically all industrial heating purposes.

With the process and apparatus outlined above, it will'be seen that the manufacture of gas may be thoroughly controlled, and that the process will give a very good heat balance because the fuel is introduced and removed fromthe generator substantially cold, and the residual vheatin the gas is substantially all removed to the waste'heat boiler. The heat of the gas is. used for generating steam and for superheating the steam.

This case is a division of my copending patent :means for introducing. solid: fuel into .the upper portion of the shaft, means for removing carbonized'fueland ashes-from the lower portion of the -shaft:.centrallyrthereof, a pair of independentlyapplication Serial No. 640,828, filed May 23,1923, for Manufacture of fuel gas, now maturedfas Patent 1,837,226, dated December '22, 1931;

'The preferred form of the inventionnhaving been thusdescribed, what is claimed as new is:

I claimi I 1. A gas generator comprising'an upright shaft, meansfor introducing solid fuel: to the upper portion of the shaft, means for removing carbonized fuel and ashes from the lower portion of theishaft,

, a pair of-preheaters, a pair of blast inlets respectively connecting the. midportion of itheshaft with the respective preheaters, a gas .offtake mounted in the central portionof the. shaft with an inlet adjacent the vertical mid-portion of the same, a steam superheater supportedin the said gas ofi-take, a pair of waste-heatboilers, separate valve-controlled means adapted to conduct gas from the said gasioff-take to each of the..:said

waste heat.boilers,-means for conducting away cool gas from each of the said boilers, and separate valve-controlled means connecting eachof the said boilers with a corresponding preheater.

2. A gas generator comprising an uprightshaft,

means for introducing solid fuel to the upper portion of. the shaft, means for removing carbonized fuel and ashes from the lower .pOrtion of the shaft, a blast inlet connected to the mid-portion portion of theshaft, a peripheral gas-orf-take .connected withr-thetop portion of the shaft,:a

waste-heat: boiler, valveecontrolled indirect: heatexchange means including a steam superheater .mountedin the-first-mentionedg-as offtake, and

separate valve-controlled means respectively con- "nectingthe heatexchange'means with the wasteheatboiler and Withthe said blast inlet.

:3. generator comprising an upright: shaft,

l means for introducing solid :fuelto the upper. portion of -the. shaft, means. for'advancing thefuel through the shaft and for removing carbonized ,fuel and ashes :from the'lowerportion'of the shaft,: a valve controlled' blast inletwconnected: t0

the vertical mid-portion. of the shaft,,a' gas offtakeinthe centralportion of the-shaft with its inlet-adjacentthe verticalmid-portion of the shaft, a peripheral gas-ofitake connected .with

the top portion ofxthe shaft, a waste heat boiler,

:indirect heat-exchange means including steam superheating.elements-mounted in thefirst-mentioned: gas-ofita'ke, and valve-controlled passages respectively: connecting the heat-exchange means with the wastes-heat boiler and withthesaid blast inlet.

controlled blastzinlets connected with themidportion of thewshaft, a; preheater connectedwith each blast inlet, agas-offta'ke .mountedin the the'heat exchanger with the respective wasteheat boilers, means connecting the said heat-exchanger with. the respective preheaters, and sep- :aratemeansfor respectively introducinggas and I air: for combustion: into the respective 'preheaters.

- 5..-Agas generator comprising an .upright shaft,

controlled blast. inlets 'c'onnected'with themidportionof theshaft, a preheater connectednwith eachblast inlet, agas-offta'ke' mounted in the central portion zofith'e shaft with its inlet adjacent the vertical .mideportion of the shaftand substantially: above. the: elevation of the said .blast -inlets, a pair of waste-heat boilers, a heat-exachangeunitmounted in theinterior of the said gas ofita'ke, independent valve-controlled means connecting the heat-exchanger with the respecitive waste-heat boilers, means. connecting the said heat-exchanger with the .respective preheaters,

valve-controlled 'means .connecting each wasteheat boiler with a corresponding preheater, and

.means for respectively introducing gasand air for combustion intotherespectiVe preheaters.

:6. In gas generatingsapparatus; an upright gas "generator'shaft having means neariits base for supporting fuelin' a column in the shaft. and. for

advancing: fuel therethrough at a controlled rate, a blast air'inleticonnec'ted with the 'mideportion ofxthe shaft;vertically+spaced axiallyand' peripherally located g'as oiftakesrespectivelydisposed 'atelevations above the saidblastiinlet, the-:said :axiallyvlocated 'gas offtake havingits inletiend adjacent the vertical. mid'eportion. of the: shaft" :4. :Agas generator comprisinganuprightshaft, means forrintroducingisolid fuel into; the upper portion of the shaft; means foraremovin'g' carbonizedfuel an'd ashes from the. lower portion of the shaft centrally thereof,. a..pair of independentlyand being adapted to withdraw highly heated combustible gases upwardly from the high temperature zone of a fuel column within the shaft while maintaining them out of direct contact with the said fuel, a fuel inlet in the top of the genthe longitudinal axis thereof and adaptedtoconduct highly heated combustion gases upward axially from the high temperature mid-portion of the shaft while maintaining them out of contact with solid fuel, a pair of heat regenerators, valvecontro1led connections between the respective regenerators and the vertical mid-portion of the shaft, means in the upper part of the shaft for withdrawing combustible gases upwardly through the column of coal therein, and a pair of waste heat boilers, the said jacketed means being separately connected with the respective iregener-- ators and with the respective waste heat boilers.

HENRY O. LOEBELL.

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