US796670A - Process of making gas. - Google Patents

Description

PATENTED'AUG. s, 1905.

DQMODONALD. PROCESS OF MAKING GAS.

APPLICATION FILED SEPT.8, 1903.

ITZZ/QW UNTTED STATES ATET @FFTQE.

Specification of Letters Patent.

Patented Aug. 8, 1905.

Application filed September 8, 1903. Serial No. 172,405.

To all whom it may concern.-

Be it known that I, DONALD MCDONALD, a citizen of the United'States, residing in the city of Louisville, in the State of Kentucky, have invented certain new and useful Improvements in Processes of Making Gas, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification.

This invention relates to a process of making watergas.

It has for its object to provide a process of making water-gas from soft or bituminous coal by which the volatile matters in the soft coal are saved and utilized to enrich the gas and the soft coal is coked in a way to economically use it in the process of gasmaking.

Attempts have heretofore been made to utilize soft coal for making water-gas; but a difficulty has been encountered in that the blast in passing through the soft coal carries away the volatile matters. A ton of soft coal contains about five hundred pounds of volatlle bitumen and fifteen hundred pounds of coke.

In my inventlon the bitumen is saved and utilized by being made to take the place of oils for enriching the water-gas, and the coke made is very much cheaper than coke purchased from ovens or coal-gas works.

In the drawings I have shown in Figure 1 a diagrammatic view of an apparatus by which my process may be carried out, and in Fig. 2 a detail inside view of the valve when connectmg the annular opening in the gen erator with the superheater. Thls apparatus is claimed in my cop'ending application, filed January 3, 1903, Serial No. 140,044.

Referring more particularly to the-drawmgs, A indicates a generator in which the coking and generating of the gas takes place. This generator is provided with a series of openings at at a point some distance from its top, which openings communicate with an annular opening A in the walls of the generator.

. Above the series of openings a is an opening A Both the annular openings A and A communicate by passages 3 2, respectively, formed in a stack D, with a pipe F, which leads from one side of a passage 1 in the stack D to the upper part of asuperheater B. The communication between the passages 2 3 and the pipe F is controlled by a rotary valve E, having ports 6 and e which valve when in one position opens communication between the passage 2 and passage 1, closing passage 3, when in another position opens communication between passage 1 and passage 3, closing passage 2, and when in still another position closes passage 1, and consequently both passages 2 and 3, to the superheater. The generator A also communicates with the superheaterB through a passage M, which passage is controlled by a valve N and leads from the bottom of the generator A to the top of the superheater.

From the bottom of the superheater leads a pipe R, which is provided with a valved opening S and which connects with a seal C. The seal C is also connected with the genera tor by means of a pipe L, which extends from the upper part of the generator.

The process is performed as follows: Th generator is filled with coke a little above the line K K K. The air-blast from pipe X is sent up through this coke until it becomes thoroughly heated and until the whole top of the generator is red-hot. As soon as the coke is hot the blast is turned off, about one ton of soft coal is dumped on top of it, and the rotary valve E is turned so as to leave flue 2 open to the superheater. Steam then turned under the coke from the pipe Y passes up through the hot coke and makes water-gas. This water-gas passes throughthe soft coal, taking up with it a large amount of volatile matter, which passes out through flue 2 and pipe F, down through the superheater, and on through pipe R to the seal. As soon as the run is over that is, when the coke ceases to be incandescentthe valve is turned so as to put circular flue A into communication with the superheater. Theblast is then again sent up through the coke, heating the coke thoroughly and also heating the coal, but not passing through the coal. Such coalgas as is made during the blast passes over through the pipe L to the seal, the quality of it being judged by the test-light G and the quantity regulated by the butterfly-valve G. lf blast-gases should pass over through pipe L faster than the coal-gas is being made, blast-gases would mingle with the finished gas but their presence is immediately shown by the test-light, and the gas-maker then closes the butterfly-valve until the amount of gas that can pass over is equal to or a little less than the amount of coal-gas being made. Then coalas only will be obtained.

The vent-pipe G is left open during the early blast on the machine-that is, the blasts which are made before the coal is dumped in-so as to prevent those blast-gases which leak past the butterfly-valve from passing through the seal and mingling with the finished gas. Vhile the coke is being blasted in the usual run the blast-gases pass up through the generator A into the circular channel A, out through the flue 3 in vertical stack D, down through the checker brick in the superheater B, up through the pipe R, and out of the stack-valve S. hen gas is being made, it follows the same course, except that it does not enter the circular channel A, but passes up through the soft coal and flue 2, thence to and down through the superheater, up through the water in seal C, and passes out to the gas-holder through the pipe Q. WVhen three or four runs have been made up through the coke, the bottom part of it begins to get dead and it is necessary to make what is called a down run in order that this dead coke may be again. heated up by means of the sensible heat contained in the hot water-gas which has just passed through the incandescent coke in the top part of the generator. This down run is made by turning the valve E so as to close the passage to the pipe F, thus shutting off the top part of the superheater entirely from the generator. At the same time valve N is opened, and the pipe M from the bottom of the generator is in this way brought into communication with the top part of the superheater. When this has been done, steam is turned in either on top of the coal or into the channel A, and thus on top of the coke. This steam passes through the coke, makes water-gas, and at the same time heats up the dead coke before spoken of, and the watergas thus made passes through the pipe M into the top of the superheater, down through the superheater, up through pipe R and the pipe T to the seal. Before making this down run the coke in the generator is blasted to incandescence; but that part of the coke which is too cold to ignite is not heated by the blast, and hence must be heated by the down run in the manner described. It will thus be seen that the air-blast always goes up through the coke it is burning to carbonic oxid and nitrogen. This blast-gas (as it is called) passes over into the superheater, where it meets with a second blast of air, and by means of this second blast the carbonic OXld in the blast-gas is burned up, producing a very hot flame, which flame heats the bricks of the superheater.

The passage of the gas through the soft coal heats the coal and distils from it the volatile hydrocarbons which gives it its illuminating power. These are carried away; but the gas passed through the superheater becomes fixed, as it is called, in the superheaterthat is, the condensible hydrocarvbons become changed into permanent gases,

and in this way the volatile part of the coal, which is thrown away in the manufacture of coke, takes the place of just so much oil in the manufacture of water-gas by my process. There is no chemical reaction. between the hot water-gas and the soft coal, merely the heating of the soft coal and the mechanical. carrying away bythe hot water-gas of the hydrocarbon vapors from the soft coal.

The enrichment of water-gas with oil by means of a superheater is not new; but without the superheater the gas derived from the coal would contain a great deal of condensable matter which would have to be extracted from it and the gas produced would be too lean-that is, not rich enough for a great many purposes for which gas is usedso that the superheater serves the double purpose of converting the constituents of the coal into permanent gas and allowing me to use enough oil to bring the gas up to any candle-power required.

Having thus described my invention, what I claim is- The process of making gas which consists in providing, in a suitable generator, :1. body of coke and a superposed body of coal in contact with the coke, of a width at its bottom as great as the width at any place in. its .height and of a height to permit the passage therethrough of heat from the coke beneath; passing a blast through the coke while the coal is above it, but not through the coal, causing the coke to become 1ncandescent, and the coal to give oil some gas by heat radiated from the coke; passing steam through the body of coke to produce watergas; passing all the water-gas thus formed through the body of coal in order to enrich the water-gas; passing the enriched gas through a superheater to fix the gas; mixing the coal-gas first given off, with the enriched water-gas that has passed through the superl'ieater; and when the coke becomes cooled on its under side then passing steam downwardly through the coke forming wator-gas which is passed through the superheater and mixed with the other 'lheforegoing specification signed this 28th day of August, 1903.

D ONALD MOD O NALD.

In presence of J. A. Fonsrnn, Tnos. WV. KENNEDY.

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