US1379038A - Process of manufacturing water-gas - Google Patents

Description

W. W. ODELL.

PROCESS OF MANUFACTURING WATER GAS. APPLICATION FILED NOV-7,1918.

1 ,379,038. Patented May 24, 1921.

'1 i l I l l I I I I I I UNITED STATES PATENT OFFICE.

WILLIAM WALLACE ODEIlL, OF URBANA, ILiIINOIS- PROCESS or MANUFACTURING WATER-GAS.RE|SSUED Specification of Letters Patent.

Patented May 24, 1921.

Application filed November 7, 1918. Serial No. 261,567.

of the United States, residing at Urbana, in the county of Champaign and State of Illinois, have invented new and useful Im Erovements in Processes of Making Wateras. This invention relates to the manufacture in a generatorby means of an air blast, after which the gas is manufactured, chiefly,

by passing steam either up or down through the incandescent fuel, but with improvements in the process consisting in admitting some air with the steamduring the steam runs, and under certain specified conditions admitting steam with the air during blasting. The objects of the invention are, while 7 usin any of the aforesaid fuels:

(1% To maintain a more uniform and steady heat in the generator and at the same time a longer gas making period.

(2) To maintain control over the temperatures in carbureter and superheater. (3) To avoid the waste due to burning gases outside the water gas set by burning them in the carbureter and superheaterr greater per cent. of the fuel in the generator.

(9) To prevent the caking and arching of the fuel in generator which is a'troublesome feature in ordinary operatlon of a Water gas set using bituminous fuel.

In obtaining these results I am taking advantage of the peculiar properties of bituminous fuels, and of the present day standards for city gas, which call for lower heating' value and lower candle power'than ever before.

As far as I am aware this process is taking further distinguished from other processes or from a-combination of a water gas and a producer gas process, 1st. In that it allows a greater percentage of up runs to be made,

due to the better control of the temperature 1n the generator, thereby permitting the saving ofthe rich hydro-carbons and illuminants from the volatile matter of the fuel 1n the top portion of the fuel bed. (These hydrocarbons are cracked to a great extent when forced down through the fire as with down runs). 2nd. The quantity of steam admltted during air blasting is dependent on the temperatures in the carbureter and superheater, and on the volume of smoke produced during blasting. The gas produced during blastingis entirely consumed withln the water gas set and is not passed Into a gas holder. 3rd. That definite quant1t1es of auxiliary air and steam are used, and said quantities are under operators ab.- solute control and are changed by him whenever indications call for a change. 4th. As far as I am aware this process differs further from other processes in that one of the'uses of the auxiliary steam,'-the steam admitted during the air blasting,-is to in crease the volume of high temperature fuel in the generator by preventing the fuel on grates from becoming excessively hot, therebypermitting the use of a greater amount of air blast. The following chemical react1ons will help to explain the last statement:

51) C|O =CO exothermic reaction.

2) 2C+O =2CO exothermic reaction.

(3 CO,+C:2CO endothermic reaction. -(4 I-I,,O+C=CO+H endothermic reaction.

The first three reactions or equivalentare place during the ordinary air'blasting 0 a water gas generator. The zone of complete combustion, as in reaction #1, is invariably at the bottom of the generator, and the excessively high heats are, in common practice formed or created in this zone. In my process, on admitting-auxiliary steam 'with the air, reaction #4 takes place, and it takes-place at the overheated part of the fire, the zone directly above the grates. This cooling action. in the overheated part of the fire permits the heating of a larger zone to the most desirable temperature, which is accomplished by using more blast and by turning off the auxiliary steam before the end of the blast period. It will .be seen that as soon as fire is hot enough above the usual I hot zone, the turning off'of the auxiliary steam permits the fuel directly above grates to become hot very quickly, particularly with the increased amount of air blast as mentioned. Thus an increased volume of incandescent fuel is obtained.

In manufacturing Water gas by the standard method now in use, (by the Lowe process) it has been shown that the following at K, and L is the off-take valve.

To operate this machine according to my process air is first blasted up through fuel bed by opening valve S on air line E. When fuel bed X is heated to a sufficiently high temperature the air is shut off at valve S, and water gas is produced by admitting steam beneath the grates through up run line F, by opening valve T. A little air is admitted simultaneously through auxiliary air line B, during this steam run. During this run the valve L is closed and valve J is open. This steam with the small with the common air control valve at difficulties are encountered when bituminous amount of air forces its way up through the fuel is used as generator fuel: Heats in the fuel bed and by chemical combination pro.- generatorcan not be maintained high duces gas. The (CO carbon dioxid enough to make water gas for more than a formed from the combustion of the auxilbrief period without reblasting generator. iary air is reconverted to (CO) carbon mon- On attempting to blast the heats up in the oxid by the incandescent fuel (according to generator by an increased amount of blast, reaction 3 supra) and hence the onlydilso much combustible gas is produced that uent of the finished gas is the nitrogen it can not all be burned in the carbureter or of said air. Now this is partly compensated superheater without overheating them, and for by the increase inamount of volatile if it is burned at the stack endangers meltproducts from the bituminous fuel, and ing of the stack and causes a waste of fuel. further compensated for since the hotter The big per cent. of tarry matter and volafire now obtainin tile matter from the coal produces a heavy carbon dioxid (C which is ever present voluminous smoke which is emitted at the in water gas; forming in greater per cents. stack, causing a nuisance. The volume of as the fuel temperature decreases. Since gas produced, using bituminous fuel in gen- CO is the most undesirable inert in come'rator, is considerably lower than that probustible gas air should not be used with the duced using good coke as fuel and under steam so long as to increase the ercentage the same conditions. The fuel used per of this undesirable element. After this reduces the amount of 1,000cubic feet of gas made is considerably steam run (up run) the steam valve T' and Clinker is the auxiliary air valve Q are closed and formed to an excessive degree when bitumithe fuel is again blasted from beneath grates nous fuel is used in generator and blasted to by opening the valve S in air blast line. the necessary temperatures for water gas pro- A small amount of steam is simultaneously duction. admitted through the auxiliary steam line The figure of the drawing represents a V by opening valve W. This produces a common type water gas generator equipped richer blast gas (shown in reaction #4 to manufacture gas by my process using bisupra) which is completely burned in the tuminous or other high volatile fuel. In carbureter and superheater with the elimithe figure, A represents a generator, with 'nation of smoke and tarry matter which grates B, and fire cleaning door C, and ash pit would otherwise be in evidence at stack. door D. The charging door is shown at H. This auxiliary steam is not necessarily used E, is the main air blast line to the generator during the entire blast period, but just until with its air control valve at S. F, is the rich gas is being produced from air blast up run steam line with the steam control as will be the case when heat in generator valve, at. T. Th? down run steam line is is sufficiently high. The gas first roduced shown at G, and its steam control valve at on blasting is always very lean. ery little U. The off-take to carbureter for gas made auxiliary steam is used, and usually for but during an n run is at I, and the off-take a. short time unless carbureter and supervalve is at The down run off-take is heater are not sufiiciently hot and more rich l\, is gas is needed to heat them, in which case the so-called hydrogen pipe which connectssuflicient steam is used to accomplish this down run off-take with the carbureter. The end. After this air blast when fuel is suflimain steam line is representedby N. The ciently hot, a down run is made by first air'pressure tank for supplying air to theturning off air at valve S and'turning off auxiliary air lines is shown at O. P, and steam at valve W, and then admitting steam R, represent respectively the auxiliary air through the fire from above fuel bed by lines to the top and bottom of generator, opening valve U on down run steam line. Q. When this down run is being made, valve The auxiliary steam line to the base of gen- 'L in off-take must be open, and valve J erator :is shown at V, with the steam conmust be closed. While this down run steam trol valve W. is on, .a small quantity of air is admitted greater, using bituminous fuel.

through the up er auxiliary air line P, by opening valve This air keeps the fuel up to the desired heat for a longer period of steam run, thus increasing the capacity of the water gas set. repeated except that a small amount of auxiliary steam is used on every air blast after the first if conditions require it. It is necessary. on blasting with air, or making a steam run that valve L be closed and valve J be open. I On all down runs valve J is closed and valve L is open.,

Air is nearly always supplied to the main air blast line by a fan or blower, and the air pressure procurable from such fans is usually not great enough to use this source of air to replace the high pressure auxiliar air which I prefer to use in my process. here would be danger of explosion if low pressure air were used during steam runs. For example if a little water condensed in the steam line and was blown into the generator as steam was turned on, the high pressure immediately created would force gas back into the low pressure air line and the gas and air mixture might explode and do damage. A meter, governor be used on this high pressure auxiliary air supply line. I also prefer to use an'auxili ary steam line separate from the regular up run steam line for similar safety reasons.

The auxiliary steam admitted through valve W in the figure can be regulated by a governor to give any desired-quantity or pressure, but comingthrough avery small line there is never a possibility of a great quantity of steam entering at once or an excessive pressure bein developed, and hence there is no dan er 0 back firing in blast line.

T e objects of my process are accomplished as follows:

Object 1 is accomplished by admittinga relatively small volume of air with the steam during the runs, causing combustion to take place and thereby preventing the fuel from becoming superficially. chilled, and

simultaneously lengthening the run period. Further, object 1-is accomplished by the proper use of up and down-runs consistent with the new method of blasting (with the occasional use of steam during the blast) and of making the steam run (by the use of air with the steam during therun).

- #2 is accomplished by governing the amount of auxiliary steam admitted during the blast. The more steam admitted at this time the more combustible gas is produced to burn in carbureter and superheater as shown in reaction #4 supra.

3 is accomplished on account of the fact that the slightly leaner water gas, which is produced in increased volume, requires more oil per given period of time to carburet it. This heavier duty for the carbureter and superheater requires that more heat be sup- The cycle is now and pressure gage should.

plied them and thus is it possible to burn more gas in them without the danger of overheating them.

#4 is accomplished along with #3.

#5 is accomplished by not wasting any combustible as at the stack of superheater, but by burning it as mentioned in #3 on this page.

#6. The auxiliary air admitted during the gas making period prolongs the gas making period and also produces a greater volume of water gas per given time. This, with the additional volume of gas from the carbureting oil, gives an increased capacity to a given sized water gas set. The additional volume of water gas made is not due chiefly to the added volume of gas from the auxiliary air. The gas made in generator per second during steam run in present practice,,is decidedly greater the first few seconds that the steam is admitted and then falls off. rapidly. Now, the auxiliary air used in my process during the steam run, prevents the temperature from dropping too rapidly and thus increases considerably this maximum gas making period, and also the volume per given time. I

' #7 is accomplished due to the fact that the auxiliary steam used during the blast keeps the clinker zone cooler.

#8 is accomplished by the increase in amount of blast.

#9 is accomplished, due to ditions obtaining in the generator; to the benefits derived from admitting auxiliary air during the down runs, and to the increased per cent. of high temperature fuel in generator.

The results obtained during the run with my process are vitally affected by the method of blasting, as well as by the direction of the blast and the amountof air per unit time. This is evident since the quality and quantity of the blue gas produced during the run depend on the condition and temperature of the fuel, and on the volume of the fuel that is heated to a gas making temperature. am' able (by the proper use of air with the steam during the run; with the proper proportion of up and down runs, and with the occasional, use of some steam during the blast) to obtain absolute control over the condition of the fuel inthe generator 'and better fire conam thereby enabled to make the maximum amount of high quality gas per unit of time during the run. By making up blasts only being instantly heated to a high temperature has a longer time of contact with the fuel at a high temperature than it would where the steam had to travel half way through the fuel bed before reaching the highest'temperature. The zone of'com lete combustion being at the lower part of the fuel bed in my process causes the blue gas leaving the generator to leave at a lower temperature than the highest temperature in the generator. This is particularly true on all up runs when the hot gases pass through the green fuel at the top of the generator causing distillation of much of the volatile matter from the fuel, which is retained in the blue gas which is thereby enriched.

Since less heat is removed from the generator as sensible heat per unit of gas made, it follows that more heat isavailable for gas making purposes.

I That there is definite coaction between the blast and run in my process is further evident on considering the following: I use up blasts only and use many up runs and some down runs, thus preventing too great a concentration of heat in a particular zone. This is adecided advantage over the processes that use a down blast only and follow them with up runs only, since in these processes a zone of intense heat is created near the top of the fuel bed. In such cases the generator top, off-take valve and off-take pipe are constantly in danger, (danger of over heating and melting) due to the excessive temperature created in this hot upper zone; the blue gas leaves the generator at an excessively high temperature thus causing an increase in the generator fuel per thousand feetof gas made; the steam never strikes the hottest part of the fuel bed first. The ash formed during the down blasts (being near the top of the generator) is, to a considerable extent, carried over into the checker chambers on subsequent runs. This ash deposit is a source of considerable trouble.

In my process I make use of the commonly used carbureting method consistsing in blowing or spraying oil into heated checker chambers. I recognize that this is not new and therefore do not claim patent on that process as such. However I obtain a marked improvement in carbureting results and use the old method in a new way. That is: p

(1) I make a better grade of blue gas which contains considerable volatile matter of the fuel, thus the oil is cracked in a different atmosphere.

(2) In using air during the run some producer gas is generated which further changes the atmosphere the oil is cracked in.

'(3) Since I make more blue gas (including the volatile from the fuel, and the producer gas made) more oil is required per run with a given size set than in other process, so far as I am aware. This, together with the method of blasting allows for a more perfect control over the temperature in the cracking chambers without the customary waste of blast gases at the stack.

(4) The rate of production of blue gas is more uniform in my process, on account of the air admitted during the run and on ac count of the better temperature conditions obtaining in the generator, hence the oil concentration in the cracking chambers can be maintained more uniform and the cracking more efiiciently done.

I claim:

A process for the manufacture of combustible gas by an intermittent method, using bituminous coal or other solid fuel containing volatile combustible matter, consisting in first heating a bed of ignited fuel in a generator by blasting it with air, using an up blast only, from beneath the fuel bed, and using simultaneously with this air blast a relatively small amount of steam also injected from beneath the fuel bed during the fore part of the blast period only, for the prevention of smoke, prolonging said blast, so as to better heat the upper zones in the fuel bed, shutting off said air, as well as the steam used therewith, and making up-anddown runs, a small quantity of air belng injected with the steam, during each of said runs, for the purpose of prolonging the period of said runs, and making at least two up runs to every down run for the purpose set forth.

In testimony whereof I aflix my signature in the presence of two witnesses.

Mrs. A. H. RAYMOND, A. H. Ramona.

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