US1808214A - Method of making water gas - Google Patents

Description

June 2, 1931. o. B. EVANS METHOD OF MAKING WATER GAS Filed April 5, 1924 3 a 1 b QR 22 FIG].

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//Yl/V7'0 Z2??? 2 Owen Brae 51c Evan's Paten ed June 2, 1931 UNITED STATES PATENT OFFICE OWEN B. EVANS, OI PHILADELPHIA, PENNSYLVANIA, ASBIGNOR 'I'O THE U. G. I. 0017- TEACHING COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION 01' nmwm METHOD MAKING WATER GAB Application filed April 8, 1924. Serial No. 703,893.

The efficiency and capacit of a water gas set de nd primarily upon the attainment of a hig temperature in the incandescent fuel bed in the generator. This high temperature 5 can be obtained by excessive air blasting but at the expense of the formation of undesirable clinkers diflicult to remove. The use of superheated air and superheated steam for obtaining and maintaining that hi h temperature presents mechanical di culties which include the maintenance of valves and grates to withstand that temperature.

By my invention the steam and air blast are superheated by the otherwise wasted heat of the products of combustion and of the illuminating gas leaving the apparatus. No valves are subjected to high temperatures. No hot gases pass through the grate. This permits of the use of a mechanical or stationarty grate without requiring water cooling. he high temperature is produced in the body of the fuel bed where the percentage of ash compared with the percentage of carbon is relatively low and the production of this high temperature at this location does not result in the formation of clinkers difficult to remove.

Generally stated, the invention may be said to comprise the process of making water gas which consists in establishing and maintaining a fuel bed between two carbureters, hot air blasting followed by hot steaming in divided relation in respect to the top and to the portion above the bottom of the fuel bed and in undivided relation in respect to the intermediate portion of the fuel bed and through both carbureters and first in one direction and then in the other direction, simultaneously storing the heat of secondary combustion and the sensible heat of the water gas inone of said carbureters, and preheating the air and steam by the stored heat of the other carbureter, and leadin off both comparativel cool water gas an comparatively cool com ustion products alternately at the outlet of each carbureter.

The invention also comprises the improvements to be presently described and finally claimed.

In the following description reference will adapted for the practice of the invention,

provided with the necessary blast and gas connections (hereinafter described) and with grates 22. The generators contain the fuel bed considered as a whole, there being a fuel bed in each generator, but the two fuel beds may be conveniently considered as one. The fuel bed is between two regenerators shown as carbureters B, B and superheaters A, A, similar to those in common use in water gas manufacture, and the carbureters may be filled with checkerbrick ormay be empty. The vessels A, A are both superheaters and stoves and are supplied with checkerbrick for absorbing or storing and giving up or restorin heat.

ssuming the carbureted water gas set to be in normal operation, the inventlon may be described in connection with it as follows:

All thevalves being closed, blasting is performed b opening the valve 2 and stack valve 1, w ereby cold air passes down through the suprhcater and stove A where it is heated, thence up through the carbureter B where it is still further heated, and thence into the water gas generator C. Here it divides and part flows up and part flows down (above the grate 22) into respectively the top and bottom (above the grate 22) of the water gas generator C and the division of the up and down air blasting is controlled by the dampers 3 and 4, which being dampers and not valves are adapted to withstand high heats. In passing through the generators C and C the air unites with the fuel raising its temperature and bringing it into condition for the decomposition of steam on the succeeding water gas run. From water gas generator 0 the blast gases flow into the top of the carbureter B where they are completely burned by the admission of secondary air through the valve 6. The products of combustion pass through the carbureter B and superheater-A heating these vessels and es caping at a com aratively low temperature through the stac valve 1. If desired, secondary air may also be admitted through the valve 5 and the blast gases burned in the vessels. At the conclusion of the heating period or air blow period, valves 2, 5, 6 and 1 are closed, water gas off-take valve 7 opened and ordinary temperature steam is admitted through valve 8 and passes through the apparatus in the same direction as the preceding air blow. In the-passage of the steam through the vessels A and B they are further cooled and the stem is superheated and then admitted to the fuel in the generators C in a highly heated condition. If desired, oil can during this steaming period be admitted through valve 9 to carburet the generated water gas. During this steam run period the net tendency will then be to reduce the tem era-tures in vessels A and B, and to raise t e temperatures in the vessels A. and B The succeeding air blow and steam run is therefore in the opposite direction. Valves 7, 8 and 9 are closed, valves 10 and 11 opened, and air is admitted through valve 12, then passes through vessels A B C, C, B, A and out through the stack valve 10, secondary air being admitted through valves 5 and 13 or either of them as desired to burn the blast gases formed by air blasting the fuel in the water gas generators. At the conclusion of this heating period, valves 5, 10, 12 and 13 are closed, steam is admitted through valve 16, passes through the apparatus in the same direction as the precedmg air blow and by reaction with the incandescent fuel in the water gas generators forms water gas which passes out through the water gas valve 11, oil being admitted through valve 15 to carburet the water gas. The succeeding air blow and steam run are in the same direction as at first described.

By thus alternating the direction of both the low and the run through the apparatus the air and steam used for gas making are heated to a high temperature and the Water gas and products of combustion are discharged from the apparatus at low temperatures so that a comparatively large percentage of the heat generated is retained in the appiaratus and used for the purpose of gas ma mg.

When bituminous coal is used the admission of secondary air between the two generators as at 5 during the air blasting period will facilitate carbonization of the raw coal caused by the passage and combustion of the blast gases therein and burn the volatile matter evolved in the body of a fuel bed thereby storing heat in the fire where it is needed for subsequent water gas reactions.

From the foregoing description it will be apparent that hot air havingits full normal content of oxygen is introduced at a portion of the fuel bed where the percentage of carbon is comparatively high so that a region of high temperature appropriate for gas making is provided, and this region is located in an intermediate part of the fuel bed between its top and bottom. Below this region the hot air has its oxygen content reduced due to the burning so that where the percentage of ash is high in respect to carbon the latter is burned out at a comparatively low temperature so that the ash is not objectionably fused to clinker. D'escriptively this region is above the grate. Where bituminous coal is fed to the top of the fire hot air reaches it quite directly so that it is comparatively rapidly carbonized to coke which descends into the gas making region of high temperature.

The practice of the invention in connection with the apparatus shown in Fig. 2 is as has been described so that the corresponding parts of the apparatus are indicated by the same letters'as in Fig. 1. The difference is that there is a single water gas generator C instead 'of two generators and in consequence there is no air inlet 5, and the process is modified in one or two obvious particulars of which the following may be mentioned: The incoming hot air blast is introduced centrally of the generator at every other blow and the volatile matter distilled from the bituminous coal is burned in the'carbureter B at every other blow.

While-I have referred to hot blasting followed by hot steaming it is within my meaning to include hot blasting first in one direction and then in the other, or. hot steaming first in one direction and then in the other followed in the first case by additional hot steaming and in the second case by additional hot blasting. I-

It will be obvious to those skilled in the art to which the invention relates that modifications may be made in details of procedure and in matters of mere form without departing from the spirit of the invention which is not limited as to such matters or otherwise than the prior art and the appended claims may require.

I claim:

1. In the process of manufacture of water gas by alternate air and steam blasting periods; the improvement which consists in providing two separate fuel beds-of bituminous fuel in two intercommunicating water gas generators, hot air blasting from the top part of the fuel bed in one generator to the top portion of the other fuel bed in the second generator and from the bottom part of the fuel bed in the first generator to the bottom part of the fuel bed in the second generator thereby evolving volatile matter in the fuel bed in the first generator, and introducing secondary air between the fuel beds to burn the volatile matter and thereb facilitate the carbonization of raw fuel and to store heat in the fuel bed in the second generator, and

then generating water gas by steam blasting the heated fuel beds.

2. A process of manufacturing gas as practiced in a set comprising a generator containing a fuel bed and regenerating vessels connected to said generator, which process consists in the following steps: first, passing air through one regenerative vessel, admittin the entire fiow of air to the center of the fue bed and simultaneously passing a portion of the air through the top of the fuel bed and the remaining portion of the air through that portion of the fuel bed adjacent the bottom, and then passing the entire flow of air and air blast gases through the second regenerative vessel thereby heating it; second, re-

versing the flow of air by passing air through the second heated regenerative vessel, passing the air simultaneously through the top of the fuel bed and through that portion of the fuel bed adjacent the bottom and takin off the entire flow of air and air blast gases om the middle of the fuel bed, and leading the gases through the first regenerative vessel; third, passing steam through the first regenerative vessel, admitting the entire flow of steam to the center of the fuel bed and simultaneously passing a portion of the steam and the resulting Water gas through the top of the fuel bed and passing the remaining portion of the steam and the resulting water gas through that portion of the fuel bed adjacent the bottom, and passing all the resulting water gas through the second regenerative vessel; and fourth, reversing the flow of steam and water gas through the set by passing steam through the second regenerative vessel, simultaneously passing a portion of the steam and the resulting Water gas through the top of the fuel bed and passing the remaining portion of the steam and the resulting water gas through that portion of the fuel bed adjacent the bottom and taking off the entire flow of steam and resulting water gas from the middle of the fuel bed, and then 1passing the resulting Water gas through the rst regenerative vessel.

OWEN B. EVANS.

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