US240165A - mtjller - Google Patents

Description

- 4 Sheets--Sheet 1.

R. MULLER.

Patented April 12,1881.

'Gas Generating Furnace.

(No Model.)

No.240,l65.

(If/y IN VBNTOR a%%% ATTORNEY R, WASHINGTON D. 0.

N4 PETERS, PHOTQLXTHOGRAPHE WITNESSES 4 Sheets-Sheet 2.

(No Model.)

B. M't'ILLER. Gas Generating Furnace.

Nd.240,l65.

Patented April 12,1881.

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ATTORNEY P MOTO-Llmcammizi. WASHINGTON u (A (No Mqdel.) 4 Sheets-Sheet a.

, R MULLER.

Gas Generating Furnace. No.-240,165. Patented April 12,1881.

' mun $11 ATTORNEY WITNESSES:

a /Y7 I 4 Sheets-Sheet 4.

(NoModeL) R. MULLER.

Gas Genera ting Furnace.

Patented April-1 2,

WITNESSES N. PEriRs. PHOTO LXTHOGRAPNEIL wAsnmGmN, 0 c,

. UNITED STATES PATENT OFFICE.

RUDOLF MULLER, F BERLIN, GERMANY.

GAS-GENERATING FURNACE.

SPECIFICATION forming part of Letters Patent No. 240,165, dated April 12, 1881.

Application filed April 1, 1880. (No model) i To all whom it may concern:

Be it known that I, RUDOLF :MljLLER, of the city of Berlin, in the Kingdom of Prussia,

German Empire, have invented Improvements in Gas-Generating Furnaces, of which the following is a specification.

This invention relates to improvements in gas-generating furnaces without special gasgenerators, and more especially to improvero ments in the construction of the kilns, ovens,

850., for which I have heretofore filed an application for Letters Patent, under date of February 9, 1880, and No. 2,406.

This invention is designed to produce a more 1 5 perfect and economical combustion of the fuel, by obviating the loss of heat incidental to im-. perfect combustion in the common grate-furnaces, and also the loss of heat caused by the drafts of the chimneys.

It may be prennsed here that the most perfect combustion of fuel hitherto known is produced by the gas-generating furnaces with separategenerators. Thesefurnaces, however,

- consistof several separate parts of a fire-place 2 5 proper, of a gas-generator, and of lines, and

sometimes, in addition thereto, of a generator or an apparatus by which the fire-gases and the air required for combustion are heated up to higher degree of temperature preparatory 0 to their combustion. In these furnaces the fuel is fed" into a shaft and burned in connection with a strong air-current, by which a complete combustion is obtained. The carbonic acid developed by the combustion takes up carbon in the upper layers of fuel and forms carbonic oxide. Simultaneously therewith carbureted hydrogen is formed, and some portion of the water contained in the fuel is decomposed by the heat. The result is, that the combustible 4o gases are finally drawn off to the generator at a lower temperature, owing to the transformations which take place. Another part of the heat is lost by radiation of the walls of the generator and fines, so that it is necessary to reheat the gas to a higher temperature in a regenerator, which is interposed between the generator and the space where the gases are to be burned. There a high degree of heat is obtained without special devices for the combustion of the gas, and the fuel thereby utilized in the most complete manner.

Various systems of furnaces with generators have been devised, which, though having greater or less theoretical value, are for practical purposes too com plicated and not adapted 5 5 for a great number of applications.

My invention has for its object to dispense with the separate gas-generators described, and to generate carbonic-oxide gas and other products produced by a coking of the fuel, and to produce the combustion of the gas in the same space, but in a higher portion or zone of the same, by the introduction of air which has been heated up in its passage through proper channels. The incombustible gases are drawn 6 off to the atmosphere by separate channels without employing a chimney, which latter is dispensed with in my construction. This method of burning the gases which are generated in the same space without a special generator I have heretofore to some extent described in my application filed February 9, 1880.

In this application I intend to describe the adaptation of-iny system for porcelain and other ovens, for the economical heating of stoves, steam-boilers, and other technical applications.

The following elements occur in every specific application of mysystem of heating:

The gas-generating part consists of a boxshaped open fire-place with grate and ash-pit, which latter can be hermetically closed. The door of the ash-pit is only opened when the \tire is started, so as to obtain the heat necessary for the proper coking of the next layer of fuel and the generation of gas. As soon as this heat is obtained, the ash-pit dooris closed and a small slide in the same opened, so that only sufficient air is admitted to keep the fuel 0 in its coking state for the formation of the firegases. Owing to the small amount of air required, the gratemay be constructed in a different manner from the grates commonly employedin furnaces. Theintersticesbetweenthe 5 grate-bars have to be only large enough to admit the removal of the ashes, as no clinkers are formed, owing to the comparatively low temperature. The open spaces can therefore be made small and the top surface of the bars large. The grate-bars can even be made of bad non-conductors of heat-such as fire-clay,

or fire-clay mixed with coal-dust--Which gratebars are soon at red heat, and assist thereby in the generation of gas. Above the grate is an opening, which is closed by a regulatingslide, and above this slide a door for supplying the fuel, which door may also be hermeti-- cally closed.

As soon as the fire is started, the ash-pit door is closed with the exception of its slide, and then the bottom layer of burniu g fuel covered by a layer of dry fuel, after which the supply-door is also closed. At first a lively development of carbureted hydrogen takes place until all the water in the fuel is expelled. Then the formation of carbonic-oxide gas begins, the required oxygen being partly taken from the airin thefire-place and partly drawn in through the regulating-slide immediately above the grate. The combustible gases thus obtained are burned in the higher parts of the furnace after they have mingled with the air supplied by separate channels. The channels are so disposed that the combustion in any part of the furnace can be easily regulated, and are provided with means for closing them tightly whenever required. A channel above the supply-door serves forlooking in and supervising the combustion.

The next essential feature of my system of heating is the drawing off of the incombustible fire-gases, which are generally collected near the bottom of the fire-place and mostly close to the walls, as here the least interruptions take place. These gases consist of aq ueous vapors, carbonic acid, nitrogen, &c., which are heavier than the atmospheric air. To draw them off, channels extend in the furnace-walls from the bottom of the furnace toward the top and open into the air. All the heavy gases pass off through these channels, so that chimneys can be dispensed with, as there is no need ofa draft in this system of heating. To still more facilitate this drawing off of the heavy gases, the channels may be connected with a kind of gutter below the bottom of the furnace.

In addition to the means employed for getting rid of the heavy gases there have to be channels for the removal of the lighter incombustible gases from the top part of the furnace. These channels begin at. the highest part of the top, are extended downward in the walls, and arranged to open into one of the channels through which the heavy gases are drawn ofl. These downward-extending channels are provided with a slide for being opened or closed. The light gases are drawn off by suction as soon as the slide is opened, at any time when the dull burning of the flame indicates the presence of too great a quantity of gases. As soon as the flame is bright'and clear the slide is closed. This system is applicable to every furnace, and can be used with furnaces already erected without great changes. Itis, however, best adapted for furnaces having an open fire-place and no fiues--such as brick'and lime kilns, porcelain, drying, and other ovens and also for steam-boiler furnaces, as will appear more fully hereinafter.

In the accompanying drawings, which illustrate my invention and to which reference is made, Figure 1 represents a sectional side elevation of a brick-kiln constructed according to my improved system. Figs. 2 and 3 are, respectively, a horizontal and a vertical transverse section of the kiln on lineazac, Fig. 1, and y y, Fig. 2. Fig. 4 is a detail section through one of the fire-places, showingthe disposition of the air-channels. Fig.5 is a horizontal section of a brick-kiln divided by partitions into chambers, and constructed according to my system. Fig. 6 is a vertical central section of a limekiln with my improvements. Fig. 7 is a sectional elevation of a porcelainoven. Figs. 8 and 9 are vertical longitudinal and transverse sections of a heating-stove. Fig. 10 is a vertical longitudinal section of a bakers oven, all constructed according to my system; and Figs. 1.1, 12, and 13 are vertical longitudinal and transverse sections and a front view of steam-boiler with a furnace arranged with my improvements.

Similar letters of reference indicate corresponding parts.

Referring to the drawings, a a are the fireplaces, each of which is arranged with an opening, b,'for supplying the fuel. The supplyopening bis divided, by a short horizontal partition, f, into two channels, the lower and smaller of which is closed by a double slide, 9, while the upper and larger is closed by the door 01. The double slide 1 serves to admit the air for the proper coking of the fuelin the fire-place, and for the generation of the gases from the layer of fuel above the bottom layer.

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In Fig. 1 the slide 9 and door 61 are shown on one fire-place only, but left off in the remaining ones. The ash-pit h is closed by a door, I, having a small opening and slide, 2'.

At each side of the fire-places a a is arranged a group of openings, which communicate with channels m and m, through which the air required for the combustion of the gases is conducted into the interior space of the kiln. They extend parallel to the fire-places back to the rear wall or to the partition-wall of the kiln, then upward in the wall, where they open to the interior of the kiln at different heights, the air-channels m being run up higher than the channels m, as shown clearly in detail in Fig. 4.

Converging channels it n extend from both sides of the supply-opening b toward the rear part of the fire-place a, and open there into the same. A second set of channels, a, above the channels a run first in horizontal direction, then upward in vertical direction, and open into the kiln at about the height of the channels m, as shown in Figs. 1 and 3. Above the supply-opening is arranged a horizontal channel,19, which serves to control the progress of the fire. All the channels can be hermetically closed by slides or covers in the same manner as the doors and slides g and i. The channels it serve, mainly, for the purpose of supplyin g the air necessary for the ignition of the gases generated in the upper part of the kiln. They need not be made as large as the other air-channels. All thechannels can either be formed in the brick walls or be made of pipes of clay or other material. By this arrangement of air-supply channels the first or direct firing, which is necessary to dry the green bricks during the first part of the burning process, can be kept up, the gases of combustion being conducted off directly through the top channels, 0 0. WVhen the bricks have been exposed for twenty-four to forty-eight hours to the direct firing they can be exposed to a greater heat, and the generation of gas is commenced by closing first the top draft-holes, 0, by means of clay plugs. The products of combustion are now drawn off through the channels 1", which begin close to the bottom of the kiln, one being arranged intermediately between the fire-places in the side walls, and two in each of the end walls. These channels extend upward and pass out through the top of the kiln, as shown in Fig. 1. The heavy products of combustion, which settle at the bottom, are thus drawn off through the channels 1", while the light products pass through the channels 8 s, which begin in the top of the kiln vertically above each fire-place and run downward, as shown in Fig. 3, being finally connected to one of the channels 1". Each channels can be shut off from the channel r by a slide, t. (Shown in Figs. 1 and 3.) These slides t are closed after the top draftholes, 0, have been plugged. The ash-pit doors are also closed; but their slides are opened suffieiently to keep the fuel in the tire-place aglow. A layer of fuel is now placed on the burning bottom layer, after which the supply-opening d and the slides g are closed. A lively generation of gas now takes plaoe,a sufiicientquantity of air being supplied through the channels m m and n n to maintain a steady and complete combustion of the gases. As the gases are burned as soon as generated and mingled with air which is heated up in its passage through the channels, a high temperature is obtained. As the airsupply openings are properly regulated for the perfect combustion of the gases, there is no draft in the kiln, and all the heavy products of combustion, including the nitrogen of the air, settle at the bottom of the kiln, where they are drawn ofl' through the channels 1'. These gases heat up the walls of the kiln, they giving up all their heat and passing out into the atmosphere at a low temperature, consisting mainly of carbonic-acid gas and nitrogen.

After the fuel has given off all its gases, it is burned by admitting a limited supply of air. This is accomplished by opening the slides 9 below the supply-door. The carbonic-acid gas which is thereby formed is burned in the same manner as the gases before obtained. The slide of the ash-pit door can, for this purpose, be somewhat opened. After three-quarters of an hour or an hour the fuel is entirely burned, and a new layer is supplied, and the process first described repeated. In case the layer of cokes on the grate becomes too high, the ashpit door is opened for some time, and aperfect combustion of the cokes obtained. until the layer of cokes is reduced to its normal thick ness of from eight to twelve centimeters. After three or four hours there will be noticed through the controlling-channel p dark spots in the gas, which become more and more numerous, and change finally into streaks, until the tire seems to disappear entirely and the flame, mixed with smoke, appears in the controlling-channel. This is caused by the increase of the lightproducts of combustion in the upper part of the kiln. which force the heavier gases downward. The slides tare now opened, and the light gases drawn off with great velocity through the channels .9 and 1'. When all the light gases are drawn off, the flame resumes its brightness, and theslides t are closed again. In such kilns or ovens, in which the construction of the inclinedchannels 25 would be too difficult, the gases can be drawn off directly through top channels pro vided with covers t, which are operated by a system of levers, t, or otherwise, from below.

I have described fully the working of my system of heating in connection with a brickkiln; but it is evident that the essential features employed can also be used for other kilns. I will describe a few applications of the same.

In Fig. 5 a brick-kiln with eight chambers is shown, in which the air-entrance channels are shown, but. the discharge-channels are omitted. The latter may be arranged either in the manner described or the gases may be drawn off from one chamber into the other, so as to be utilized in the next chamber. In the latter case the partition-walls are arranged just above the bottom, with communicating channels and slides, so that the gases can be drawn from one chamber into the next adjoining one, in connection with the draft-channels for the preparatory heating up of the green bricks or-other material in this chamber, and so on successively. In Fig. 6 the same system is applied to a limekiln, inwhich all the airsupply and gas-discharge channels are shown, as before described. Fig. 7 shows a porcelain-oven arranged in similar manner, but withaforward-projectingfire-place. Thechannels are, however, for the sake of greater clearness, not all shown. Figs. 8 and 9 show the application of the same principle to a common heating-stove, and Fig. 10 to a bakers oven, while the application of the same to the furnaces of steam-boilers is shown in Figs. 11, 12, and 13. In Fig. 11 the steam-boiler was formerly arranged with an interior furnace; but as such a furnace is not adapted for direct gas-burnin g without generator, the furnace has been placed in front of the boiler. For conducting oi the heavy products of combustion from the neighborhood of the grate, the tubes 1' are employed, which are separated from the grate a by means of abntments. Fig. 13 represents the fire-doors d, the ash pit doors I, with the slides 2', and the slide g, which are Worked in the same manner as the analogous parts of the kiln before described. The gases are generated in the same manner and burned in part above the tire, but mainly in the lines, into which the air is introduced, in heated state, through channels 1". The combustion takes place slowly and steadily, and requires no chimney, as no strong draft is required for carrying off the gases of combustion and keeping up the fire. In cases where the chimney has been used the same has to be nearly entirely closed by the damper. The remaining gases of combustion are drawn off through the partly-opened damper of the chimney or through special eXit-channels. Besides the complete combustion of and economy in fuel, this system, as adapted to steam-boilers, has the advantage that when the boiler is stopped by closing all the channels and openings, a sufficiently high temperature is retained in the furnace to continue the generation of gas and the burning of the same as soon as the boiler is required for work again. The work of the boiler can be interrupted up to twenty-four hours, which is of considerable advantage in many cases.

Having thus described my invention, I claim as new, and desire to secure by Letters Patent 1. The method herein described of heating kilns, ovens, steam-boilers, 800., without a separate gas-generator, consisting in generating carbonic-oxide gas from a layer of fuel superposed on a coking layer of fuel, mingling the same with heated air, and burning the gas and air mixture above the fuel, and finally drawin g off the heavy gases through channels communicating directly with the outer air and the light gases through circulating-channels communicating with the channels for the heavy gases, as set forth.

2. The combination of a kiln, oven, or furv nace having discharge-channels for the heavy products of combustion, said channels extend-

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