US1814580A - Method for making producer gas - Google Patents

Description

July 14, 1931. y c. w. ANDREWS 1,814,580

METHOD FOR MAKING PRODUCER GAS Filed oct. 31, 1925 Patented July 14, 1931 UNITED STATES PATENT OFFICE CHARLES w. ANDREWS, or DULU'III, MINNEsorA, AssIGNOB, BY branca" ANnnasNn AssIeNMEN'rs, fro n. A. BnAssEafr a COMPANY, or CHICAGO, ILLINoIs, A conronA- TION 0F ILLINOIS METHOD FOB MAKING PRODUCER GAS Application led October 31, 1925. Serial No. 65,940.

This invention relates to a new `and improved method for making producer gas and more particularly, to such a method in which thermal eiciency is increased by operation under'the counter-current 'principle of heat transfer.

It is well known in the art that the amount of steam used in gas producers is largely governed by the character of the ash. Should it clinker easily, more steam is required to prevent clinkers as up to the present time there is n0 mechanical ash removing device vwhich will adequately handle large pieces of hard clinker.` Although the slagging type of gas producer llas been developed to solve this problem and also makes possible a deep fuel bed, nevertheless no commercial installations are known to be in use in this country owing to trouble in making liquid slag and removing it.

It is recognized that carbon monoxide is a better gas than hydrogen for many heating operations on account of its greater specific gravity and also on account of the increased radiation from the burning gas. .It is also recognized that the undecomposed steam passing through the producer is detrimental V as it not only requires heat to makeit, but

it also carries out of the fire bed its own sensible heat. This is especially objectionable in high temperature operation as the flame temperature is materially lowered. The amount of blast furnace gas or other carbon dioxide containing gases it fis possible to use in place of steam, depends upon the lire temperature which must be suiciently high, not only to effect the desired decomposition of carbon dioxide, and also, the decomposition of the small quantity of water vapor which is' usually found with the ases, but also to supply the amount of sensible heat the gases carry out of the vfire bed of a prbducer. This is a considerable item as gas producers ordinarily run at a top temperature around 1300 to 14009 F.4

It is evident that if the counter-current principle of heat transfer could be .used a material saving could be obtained` How.

ever, the result of such a procedure would be the formation of large clinker masses,

which up to this time has made such a 4method of operation impracticable.

The applicant has recognized. the above and in co-pending applications" has sought to better thesel results by various means. The application of the applicant, Serial No. 1,157, filed January 8, 1925, issued A ril 16, 1929 as Patent N 0. 1,709,107, disc osea a method of breaking u such clinkers and the joint application of apman and the applicant, `Serial No. 737 ,238 filed September 12, 1924, issued April 16, 1929, as Patent No. 1,709,834, shows the necessary mechanical means to accomplish the purpose. Inasmuch as these inventions have been perfected, it is now possible to operate a gas producer for thermal efficiency without being handicapped by the formation of the large clinkers. Relatively deep fire beds and also much higher temperatures can be used, both resulting ina largely increased roduction per unit of capacity and also ma 'ng a bettergas, as practically all of the steam used will be decomposed and the ercentage of CO2 reduced to a minimum. t is also now possible to operate such a producer so as to take advantage of the counter-currentk principle, referred to above. Air and steam or blast furnace and other gases may be admitted from either top or bottom, either together or alternately, whatever way may be most desirable. Blast furnace or other gases it provides `means for producing the required steam, or acts as a standby source of steam supply should blast furnace or other gases be normally used, as the checkerbrick in the regenerators can be so constructed as to be readilyused as a flash boiler.

It is an object of the present invention to provide new and 4improved means for the leaving the apparatus is reduced` to a minimum and which may be carried out in various manners by the joint or separate use of air, steam vand metallurgical gases containing a considerable portion of carbon dioxide. l y

Other and further objects will appear as the description proceeds.

I have illustrated in the accompanying drawings a,v preferred form of apparatus' ada ted for carrying out my improved method, the apparatus being in itself no part of the present invention.

In the drawings,

lFigure 1 is a vertical section of the apparatus and Figure 2 is a horizontal section taken on line 2 2 of Figure 1.

The apparatus comprises the gas producer 11 having the charging bell 12 and the fixed grate 13. The bar or agitating beam 14 extends across the grate and has its ends secured to the ring 15 whichA rotates upon the balls 16. The lower portion of the rlng 1s provided with the gear 17 which 1s driven by means of pinion 18. Power is supplied to the'pinion 18 in any desired manner. The

bottom of the producer is entirely enclosed` by the housing 19. Thel circular ash tray 20 is carried b the ring 15 and ashes are scooped from the tray bymeans of the adjustable scoop 21. Ashes are moved through the door 22. Ashes falling through the grate 13 may be removed through the door 23. The bottom housing 19 is connected to the passage 24 controlled by valve 25 and. the passage 26 controlled by valve 27 leads from the assage 24.

T is type of apparatus is shown more yin detail in my co-pending application, Serial Y N o. 1,157 filed J anuaryk 8, 1925 now issued as Patent 1,709,107 of April 16, 1929. The reenerator 28 which 1s provided with the eating flues 29 has its upper end connected by passage 30 with the upper end of the gas producer 11. The passage 31 controlled by valve 32 leads into the lower end of the regenerator 28. The passa e 33 controlled by valve 34 leads upwardly rom the passage 31.

In carrying out my method by the use of this a paratus, the air,` air and steam, or blast Furnace .or other gases such as spent or burnt or-partially burnt gases from other furnaces or apparatus, and containing carbon dioxide and which are to be used are 1,'s14,5so t" introduced through the passage 24, the valve 25 being opened. These pass upwardly through the ash and clinker inthe bottom of the producer, then through the lire zone and upwardly through the raw fuel in the upper portion of the producer in which a thick fuel bed may be' carried. The oxygen in the gases unites with the carbon of the fuel to form carbon monoxide and this gas forms the basis of the gas desired. The heated gases, after giving up some of their heat to the fuel in the upper portion of the producer then pass through passage 30 to the regenerator 28 where they give up additional heat and are led off through passage 3l, valve 34 being closed and valve 32 being opened, to the desired point of use or to gas holding apparatus, not shown. The gas run may be then reversed and the incoming gas or gases brought in through passa e 31, and passed through the regenerator w ere they pick up heat, then passed down through the fuel and out through the clinker and ash where they give up much of their heat before being led o through the passage 24 to the point of use or to a gas holder.

It will be understood that the gasesvused and introduced into the producer may be widely varied. Steam and air may be introduced `alternately or together. It should be noted, however, that this alternate introduction of steam and air will not be for the purpose of producing water gas according to the water gascycle of operation. The gas to be made is producer gas containing nitrogen and with carbon monoxide as its major combustible component. The air may be introduced under low pressure as in producer practice and when the heat of the fire is raised to as high a point as is desired for the production of carbon monoxide, irrespective of the formation of large clinkers,

the supply of air will be shut off and steam introduced to cool the fire, largely by its decomposition, to such a degree as may be desired for eflicient operation. The steam may be introduced together if desired, in which case, they will be proportioned so as to maintain the desired fire temperatures for gas production withoutvrelation to clinker formation.

It will be understood that the main purpose for the introduction of steam in usual producer practice is not the production of blue water gasto mingle with the carbon monoxide formed by the im rfect combustion caused by the air intro uced, but is the maintenance of proper working temperatures vand the utilization of the excess heat of the-combustion. A continuous air blast alone would produce a gas of low latent heat contentleaving the producer at a high temperature with consequent loss of sensible heat and would ,further raise the temperature in the producer so high as to clog it air. and` with molten slag. By the introduction of steam in proper proportions, the excess heat of the exothermic reaction of combustion is utilized in the endothermic reaction of dissociating the steam. The products of the latter reaction are combustible and thus much of the heat is utilized in making useful gas. Due to continuous operation in one direction, however, in ordinary producers much sensible heat is lost as the gas leaves the producer at a relatively high temperature.

Metallurgical gases such as blast furnace or -other gases which contain much carbon dioxide together with some carbon dioxide land water vapor, may be substituted for steam in my improved method of operation. These gases reduce the temperature in the producer and utilize the excess heat of combustion by the endothermic reaction of breaking downthe CO2 to lC() as well as the reaction of breaking down the water of any water vapor content. Such gases thus function in substantially the same way as steam insofar as the process broadly is concerned.

Where blast furnace orlother metallurgical gases are used, which gases contain a large proportion of carbon dioxide, these gases may be alternately introduced from above and below as has been described. The carbon dioxide of the gases will react upon the carbon of the fuel and will be largely broken down to carbon monoxide, thus very greatly raising the heatvalue ofthe gas.

By the use of apparatusof the general type shown and described, my method may be advantageously carried out. A minimum of heat is carried away -from the apparatus, since by the application of the counter-current principle much ofthe heat is retained. In the downrun, this heat is retained in the clinker and ash below the fire zone and is pickedV u by the incoming gases u on the uprun. llpon the uprun, in the orm of construction shown, some of the'heat is retained by the fuel above the fire zone in the producer and additional heat is retained in the re enerators shown. f

Obviously, the apparatus `is capable of modification, such for example, as sup lying an additional regenerator associate with passage 24 so that regeneration of the incoming air and gas may be had 1n both up and down runs. On the other hand, the regenerator shown may be dispensed with and by usin deep fuel beds, the ash and clinker below t e fire zone and the fuel above the fire zone may be the sole regenerating means. The revolving bar of the type shownserves .to drop the clinkers off of its vertical edge and to break them u into small masses -which are readily disc arged and removed. The method of operation which produces large clinker masses is, therefore, 'not objectionable when using thisapparatus since without diiiculty in the normal tinuously breakin these masses are broken up and removed operation of the apparatus.

When using blast furnace gases in the producer, these gases will be used as they come from the blast furnaces without being washed and their content of iron and other materials will be takenup bythe fuel and ash in the producer as the gas is passed through. The iron. will be present in the clinker coming from the producer and this clinker maybe charged back into the blast furnace and the iron recovered in this manner. No sintering will be necessary. This method, therefore, has the advantage of recovering the iron content of the blast gases directly in a usable form and avoids the necessity for washing the gases. The ases are also enriched by largely breaking own their carbon dioxide content to carbon monoxide.

While one form of apparatus particularly ada ted for carrying out my process has been s own in the accompanying drawings, it is to be understood that it may be carried out by other apparatus and'I contemplate such changes and modifications as come within the spirit and scope of the appended claims.

1. The method of making producer gas, which comprises admitting mixtures of air and gases containing a substantial quantity of carbon` dioxide gases, said gases being capable of forming more combustible gases through endothermic reactions in a highly heated deep fuel bed, said admissions being alternately from the top and bottom of a gas producer, the periods of alternation being so timed as tocausethe sensible heat of the out-going gases to be largely transferred to the incoming gases, and continuously breakin up and removing mechanically the as es and clinkers which form.

2. The method of making producer gas, which comprises the successive admission of air and of combustible gases containing substantial quantities of carbon dioxide, said combustible gas being capable of forming more highly combustible gas through endothermic reactions in a highly heated deep fuel bed said successive admissions of air and gas being alternately from the top and bottom of a producer, the-periods of alternation being such asA to vcause the sensible heat of the out-going gases to be largely transferred to the in-comin gases, and conup an removing mechanically the as es and clinkers which form.

y 3. The method of making producer gas which comprises thesuccessive admission o lmixed aix` and combustible gases containing substantial quantities 'of carbon dioxide, 130

said combustible gas being capable of forming more highlyvcombustible gas through endothermic reactions in a highly heated deep fuel .bed', such said successive admissions of mixed air and gas being alternately from the top and bottom of a gas producer passing the outgoing generated producer gas into a regenerator'inheat exchange with the incoming air and gas whereby the sensible heat of. the producer gas is largely transferred to the inco mixed air and gas, and continuously brealn'ng up and removing mechanically by an agitating beam,'the ashes and clinkers which form.

Signed at Chicago, Illinois, this 28th day of October, 1925.

CHARLES W. ANDREWS.

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