US1733622A - Process for making mixed water gas and coal gas - Google Patents

Description

Oct. 29, 1929. J, OCQNNOR 1,733,622

- PROCESS FOR MAKING MIXED WATER GAS AND C OAL GAS Original Filed April 14, 1925 MTOR -, zajzzawrfia Patented Oct. 29, 1929 2 UNITED STATES PATENT OFFICE oHNir. ocomvoraor nocx ISLAND,.ILLINOIS rnoonss ron MAKING mxnn WATER GAS AND, coAL GAS Original application filed October 12, 1921, Serial No. 507,288. Divided andth is application filed April 14, 1923, Serial No. 632,007. Renewed April 8, 1929.

The purpose of this invention is to provide an improved process for producing com bustible gas composed of a mixture of socalled water gas and coal gas, util zing 5 such carbonaceous material as bituminous coal, coke, ligni te, and the like, and Which shall not only produce the gas more cheaply than it is now being manufactured by ap-, paratus in common-use, but shall also oper- 1O ate efficiently on a small scale, so that the process is welladapted to be employed in an individual plant of any large commercial user of gas for heating or power. The process consists in the various steps and features hereinafter described as practiced in apparatus of the type shown in thedrawin and in accordance with the attendant claims, Y. In the drawings, which are diagrammatic:

Figure 1 is a top plan view of an apparatus adapted for this process, showing only the.

parts above the section line 2'2 on-Figure 3;

Figure 2 is a transversesection of the apparatus taken as indicated at the line 22 on Figure 3.

I Figure 3 is an elevation of said apparatus.

For understanding the process, it is desirable first to describe the apparatus indicated by the drawings. This consists of a palr of twin gas generators, 1 and 2, which are structurally similar and, contain the usual grate bars and fire pots common in gas generators,

as more fully illustrated in my co-pendin'g apvplication, Serial No. 507,238, filed; October 12, 1921, of which this application 1s a dim- 'sion.

The generators are coupled together both above and below the fire pot or combustion zone by pipes, 3 and 4, respectively, provided with valves,5 and 6, whereby the flow of gas 'from'one generator to the other may becontrolled as to its path. 4

Each generator also has upper and lower discharge or oft-take pipes, 7 and 8, respectively, leading to water seals, 9, from which the gasoutlet pipes, 10, may be understood as,

connecting- With a common gas holder, not shown. Each generator also has a steam supply' connection, 11, with inlets,'12-and 13, opening into the. generator respectively above either of thegenerators at will.

the additionof such material as tar, fuel oil,

open, so thatthe gaseous pro and below the fire pot; and, in addition, each s of the steamlines is fitted with an air mixer, '14, connected in a by-fpass pipe, 15, so that either steam alone or a mixture of air and steam may be injected at 12 or 13, as desired. Suitable valves are shown in these pipe con- '55" nections for directing and controlling the steam supply. I a

An .a'irblast pipe, 16, has branches 17 each controlled by a valve, 18, for supplying air to Ordinarily, the connections described are adequate for producing fuel gas of various qualities, but when illuminating gas is required, the proper enrichment is secured by or-the like, supplied through in the top of each generator. 1

The operation of the process is as follows:

injectors at 19,

U p-mm operation -generators, 1 and 2, are filled to a height of about nine feet with carbonaceous material,---- for example, bituminous coal, preferably broken to nut coal size. A fire being started in one of the generators, say the chamber 1, the charging doors, 2(), are closed; the valves, 5 and 6, are closed, and the valves 21, 22, and 23, are closed. The blast controlling valve, 18, leading to the generator, 1, is open, so that an air blast is supplied to the fuel to induce and accelerate the combustion until the body of fuel becomes incandescent, reachin a temperature of from 2,000 F. to 2,500 E, which, according to experience, is the .best temperature for making what is called blue water gas, It maybe understood that while an air blast is at present the most economical means ofinducing combustion, there may be some certain conditions under which substantially pure oxygen or' ozone might be supplied for, this purpose,- or other chemical reagents might be employed to react with During this operation, the cap valve, .24, which surmounts the stack, 25, leading from the gas off-take pipe, 7, is left nets of com-. up process,

bustion, during this blowing passes out through the'stack. 1

When the desired temperature is reached, the air blast is shut oif at the valve, 18,'Iand the cap valve-,- 24, is closed. The valve, 5,- conn'ecting'the two. generators is opened, and the valve, '-26-,;in the off-take, 8, of the gen erator, 2, is opened to. give access to-the water seal, 9. The ,cap valve, 27, andthe valves 28 and 29, are closed to confine the out-flow of gas tothe path through the valve, 26.

Steamis now admitted to the generator, 1,- at the lower inlet, 13, below the grate, so that, as thesteanl passes up'through the hot fuel bed-,it is decomposed andunited with' the carbon, forming hydrogen, gas, carborimonoxide and methane. These hot gases, hav-. ing atemperature of from 1,300 F. to 1,800 F., passinto the chamber, '2, through the valve, 5, and are drawn downward through the mass of fresh fuel.-therein, tending' to coke'it and drive oif the yolatile matter,

whichv unites, or mixes with. the water gas coming from the generator, 1. The result ant combustible mixed'gas passes through the grate of the generator, 2, and'out through the r so as to drive the gaseous products take,

valve, 26, into thewater seal, ,9, and thnce' through the outlet, 10 to a gas holder.

Down-mm operation After a gas-making periodof from three to five minutes, during which the tempera: ture in the generator, 1, may drop as low as 1,500 E, the steam is shut ofi and the valve,

. 5, is closed. The airblast or other oxidizing means is again admitted by the valve, 18,."for reheating the fuel bed to about 2,500

with the'cap valve,24, open. When this temperature is again-attained, the air blast is shut the stack valve is closed. Then the oil and valve, 6, is opened and steam is admitted to the generator, 1, at theupper opening, 12,

down-' ward through the fuel bed, out past the valve, 6, andupward throughxthe partially coked .fuel in the generator,-2. The combustible gas thus produced is led out throu h the off- 7, and, withthe valve, 26, e osed, and the valve, 29, opened, passes into the water seal, 9,-and thence through the o.utlet,.-10, to

a gas holder.

' More gas is madein this down-run .than'in the up-run because of the natural tendency of the hot ga's'or steam to,rise, whereas the admission of steam at the upper 'inlet,-;12, forcing the gaseous products to take a downward course through the fuel, retards its movement, so that the gas remains longer in operative contact with the incandescent fuel mass and acts upon surfaces of the fuel which were not attacked inthe preceding up-run.

The down-run'is also moreeffective than the 'up-run'beeause it tends to carry the ash and.

clinker down toward, and through, the grate; making the fire easier to clean and renderlng the incandescent mass freer from the blanket- I ing effectof the ash which would otherwise .sition proceed.

accumulate as the combustion Reversal After from six to ten gas-making runs have been made inalternate directions,-as above described making water gas in the generator, 1, and passing it through the coal in and decompo thechambe'r,'2, said'coal will be thoroughly l coked and the fuel in chamber, 1, will be prac-- tically exhausted. .Said'chamber, 1, is then.

recharged with, fresh coal or other fuel through theficharging door, 20, the cap valve,

air blast valve, 18, areclosed and the valve,

5, may be opened and the steam up-run operation .will proceed in the g'e'nerator2, fur- -nishing watergas to thefresh fuelin the,

:chamber', 1, for coking it and delivering the resufiting gas the lower outlet, 8,-the

valve, 21, being opened and the valves, '22 and 23, being closed for directing this gas through-'thewater seal, 9, and outlet, 10, to

the gas holder. It will be understood that in this up-run of thegenerator, 2, the steam is admitted to said generator at 13in the same manner as describedfor the up-run of the generator, 1. v

After theup-run has cooled the fuel bed in the chamber, 2, the valve, 5, is closed and the fuel is again blown up with the air blast, whereupona down-run is made by admitting steam at the upper inlet,'12, of chamber,.2, and passing the gas out through the valve, 6, and up through the partially coked fuel charge in chamber, 1.

I fter a number of up and down runsin the generator, 2, with delivery of the gas through the oif-take,,7, or'the oifj'take, 8, of the. chamber, 1, the fuel in chamber, 2, will become exhausted-and the fuel in chamber 1,-by this time fully. coked,' may be .heated to incandescence with an-air blast and the process again-reversed with afreshcharge of fuel in the generator, 2. Itlis thus evident that the process is practically continuous, inasmuch as the recharging of either generator may be accomplished during the blowing up of the other, and the time for cleaning out ash and clinker is reduced to a minimum by virtue of the alternating up and down runs in each generator.

By virtue ofthe provision of the air mixers I conventionally shown at 14, a: slight modification of the foregoing process is possible. for manufacturing a gas of intermediate iheat ducer gas. is from 100 to 150 -13. t.flu per cubic foot,while the combination of blue water gas and coal gas, made as above described, will,

have a value of between-300 and 400 B; t. 11,.

By the followi-ngmethod, a gas of heating value of about 200 to 250 B. t. u. will result,

and this is satisfactory for certain manu'-- e I, I v v curing fficiency without the addition of such special apparatus as re'cuperators or stoves.

facturing purposes.

Eitherv chamber, 1 or 2, being first-charged and heated to incandescence by'the air blast through valve 18, is then adjusted with connections for producing water gas, but instead of admitting pure steam, a ml'xtureof steam and air from 14 is admitted either at the lower opening, 13, or at the upperinlet,-12.

The result is a producer gas-which',upon being led into the other generator and through the fuel mass therein, carries ofl the volatilej elements of said mass, andithe resultantgas mixture passes to the gas holder through the water seal, 9, in the usual way.

. Inthis-mode of operation,"air being supplied with steam, the temperature of: the fuel mass in the first chamber is not materially reduced and this step of the operation can be continued for an hour or an hour and onehalf duringwhich time the fuel in the second chamber, through which the producer gas is passed, will be thoroughly coked. The fuel mass in the first chamber must then be replenished upto the original depth of about nine feet, and the connections reversed so as to discharge mixed steam and air through the coked-mass in the second chamber and transfer the resulting producer gas .to the fresh fuel mass and thence to the water seal and receiver.

In this method, the provision of upper and lower connections, 12 and 13, permitsmakin'g of up and down. runs with the mixture of air and. steam at will, so that any undue accumulation of ash in the fuel may be prevented by alternating thedirection of flow of the gas in the'first generator.

Or,- if it be desired to make only producer gas, each generator may be operated inde-.

pendently of theother by supplying the-mixture of steam and air and leading off the pro ducer gas through the valve, 23, or the valve, 28, as the case may be, to the other chamber.

When itis desired to enrich the gas for 'increasing its illuminating power, the material ,richin hydrocarbon, such as tar, fuel oil, and

the like, issupplied through'injectors,,19, so as to be mixed with the gas coming from the first fuel mass and then-to pass in contact with the second fuel mass as the gas flows' therethrough on its way to the receiver.

amass 'in'thefirstchamberand be du'ction of water gas; zii andcoal gas,

instead of passing'it I heat. it to,incandescence',;and finally passing to the watergas-aboveone of the fuel masses before it flows over to theysecond fuel mass, so thatany'residual earbon frointhe tar or oil may b'e'ydeposi'ted on theincandescent fuel s n y decomposed-by the steam iii the further pro- It will be recognize t close I cou- ':pling of'the two generators employed in either-form of-the process above described insures the conservationof thesensible heat of the: gases throughout 'the fprooess, thus se- It should also be no ed that the frequent reversal .of direction of-gas' ii-owthr'ough the second mass of fuel, whether itfbe' water gas composition. ',-It tends to loosen and carry down theash or clinker formed inthe second generator,--.by virtue of the agitation of the massprodueed'byalternating the direction of gas moyemene -And it results in quicker coking of thecoal than would be possible with a continuous gas admission in one direc- -,tion only. Thus the gas output per hour will be: increased byreason of-this frequent reversal in the second generator;

1: The process ofmaking mixed water gas which mas-15min providing two masses of coaIjor Iike carbonaceous material in separate gas genera-tors, causing partial combustion in one inassjiint'iliit :is heated to incandescence, passing steam for a' short time down through said incandescent mass and passing the resultant hot gases directly to and gas outlet; ".en for ,ash'ort time passing the steam up through the first mass-and passing up through the second massand thence to a theresulting gases down through the second mass and thence to a gas outl et '2. The process of makingmixed water gas an'dcoal gas asdefinedji'n claim 1,-which con'' sists in repeating the a'lterna'te downward and upward passing ofl steam through the first mass until the second mass is thoroughly coked by the water gas'generatedithen reple'nishi'ng the first mass .offuel' -while forcing air through 'the'coked second mass to steam through the second incandescent mass and thence through the fresh fuel anddischarging the resultingjg'ases.

3. The process of making mixed "water gas and coal gas'as defined in sists in repeating the alternate downward and upward passingof steam through the first ,mass until the second mass is thoroughly claim 1, which iconcoked; then replenishing the first mass of fuel, and alternately passing steam down and up through the second coked mass and f thence through the first mass, and discharg ing the resulting gases.

4. The process of making mixed water gas and coal gas, which consists in providing t'wo masses of coal or like carbonaceous material in separate gas generators, inducing partial combustion in one of said masses for heating it to in'candescence, passing' steam alternately. down and up through-said incandescent mass and directing the resultant water gas through the second mass; said water gas passing alternately up and down through the 'second mass coincidently with the reversal of the direction of flow of steam through the first -mass. v

5. The'process of making mixed water gas and coal gas, which consists in providing two masses of coal or like carbonaceous material in separate gas generators and causing combustion in onemass until it is heated to incande'scence, passing steam through said incandescent mass and passing the resultant hot water gas directly through the second vmass and thence to a gas outlet; and periodically reversing the direction of flow of said steam 4 and water gas through the system without reversingthe order in which the two masses are attacked thereby. v v 1 i JOHN J. OCONNOR.

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