US1805634A - Furnace - Google Patents

Description

May 19, 1931. J. F. OCONNOR 1,805,634

FURNACE Filed Feb. 26, 1921 2 Sheets-Sheet l 0 awu'wnfoz May 19, 1931.

J. F. O CONNOR FURNACE Filed Feb. 26, 1921 2 Sheets-Sheet 2 fitter/mug Patented Ma 19,1931

sures STATES F E NT OFFICE] JGHN rnsiucrs OCONNOR, or TOLEDO, oii'Ijo, ASSIGNOR TO-DOHEBTY RESEARCH, COM- PANY, os nnw' YORK,-N.-Y., A coaroaa'rro v, ornELAwARE memes" i Application filed February 26, 1921. SrialNo. 448,280. I

T his invention relates to furnaces and,=in1 particular, to furnaces adapted to burn either i solid fuelor gas.

In the production and distribution of gas for domestic and miscellaneous industrial uses in cities, there are periods of heavyand light demand on the distributing systems, Such periods occur at various parts. of the day and also depend on the day oft-he week and the state of the Weather. For example,

he demand on a gas distributingjsystem is ordinarily less on a warm day than on a cold day, and, particularly in the case of a gas producing and distributing company supply-.

1 ing many industrial users the demand is much less on a Sunday or a holiday thanpn Y working days.

It is impossible toproducegas efliciently at rates varying even approximately. in ac cord nce with the variations in thedemand on -l edistributing-l ines. Moreovenespecialr' ly in cases where the demand varies'greatly, it is uneconomical to provide storage for the large amounts'of gas: which, where produce tion is maintained at a fairly uniform rate,-

must be accumulated at times of small de 'mand 1n orderto satlsfy the increased dema'nd at other tunes; In view of the abojve considerations it isfimportantthat means 5 to burn solid fuel and little orno gas should be devised which will utilize economi-Y, cally allor a partiof the-excess gas which'is produced at times of small demand on a gas distributing system, and which will consume little or no gas at times oflarge demand. To this end, an object of theinvention is to provide'an improved furnace which" may be operatedwith gasattimes when thede'lmtrnd for gas would otherwisebesmall, and which at periods of heavy demand may be caused In the illustratedembodiment. of the invention, the furnace is combined with a boiler which may in turn be used for the generation of electrical current; Such a furnace and boiler would preferably be used in a situation where thereis a large andiairly' uniform demand for power {for example, in thejpower house of astreet railway company,

It has hitherto been proposed-to construct furnaces capable of burningeither gas or gas or solid. fuel.

solid fuel. I so as applicant is aware,how v ever, none of such furnaces has-been adapted to burn artificial gas of the-type produced in coke ovens. Coke oven gas is Widely used in cities -fordomestic purposes. One'of the reasons 'WlIY PI'IOI furnaces have not been adapted to burn such gas is that it has a high flame propagation which causes the combus tionofzthe gas to' takepl'ace largely in a localized area closely. adjacent to the burners and also causes the flame of the gas toflare back in an ordinary burner.

1 Accordingly, a further object of the inven -h tion-is to provide meanswhieh will be adapted to burn gas ofhighfla'me propagation such as coke oven 1 gasand which i will be capable of use 1n a :furnace constructed An important featureof thevinvention re sides in the provision, in connection witli a fire chamber in" which; solid fuel ;may be burned; ofa' bridge wall'at oneside ofthe fire chamberhaving a series of gas, burner openings and ,means for separately controlling the supply ofgas to the burner openings,

In the illustrated construction, the furnace also comprisesa rear wall' disposed at the opposite; side 'ofjthe, bridgewall from the fire chamber-and spacedtrom the bridge wall by a distance such as to enable an operative to pass between the walls in order to control the supply of gas and air to the burner open: 111 's. a p l i iother important features of the invenl tion pertainato the devices for burning the gas. Preferably, and asishown, the burners are constituted; by hollow blocks of special refractoryrnaterial, such, for example, as carborundum, arranged tol conduct gas: into the burner openings at points adjacent to the to burn either intended, therefore, that the scope of the invention shall not be restricted except as required by the claims.

Other objects and features of the invention will appear as the description proceeds and will be pointed out in the claims.

In the accompanying drawings which illustrate a preferred embodiment of the invention;

Fig. 1 is a view in sectional elevation of a furnace constructed in accordance with the invention and having a boiler associated with it;

Fig. 2 is a sectional View in plan of the furnace bridge wall taken on the line 2-2 of Fig. 3;

1 Fig. 3 is a-view of the furnace bridge wall in elevation and partly in section on the line 3-3 of Fig. 2;

Fig. 4 illustrates a portion of one of the piggs for supplying gas to the gas burners 5 1g. 5 is a fragmentary view of the devices for controlling the supply of air to one of the burner openings in the bridge wall and Fig. 6 is a perspective view of one of the gas burners.

In the illustrated construction, the fire chamber 2 intervenes between a front wall 4 and a bridge wall 6 and is provided. at its bottom with a grate 8 on which coal or other solid fuel may be burned. Coal is delivered upon the grate 8 from a hopper 10 by means of plungers (not shown) operating between theisections of the grate, and the air for supporting the combustion of the coal is introduced into the space below the grate 8 through a pipe 12.

I Extendingacross the fire chamber 2 and the bridge wall 6 is a group of water tubes 14 supported at one end on the front wall 4 and at the other end on a rear wall 16'disposed substantially parallel to the bridge wall 6. The tubes 14 communicate at their ends with headers 18 and 20 located above the walls 4 and 16 respectively. The headers 18 and 20 are in turn connected to a water and steam drum-22 by'pipes 24 and 26. Water is maintained in the drum 22 at about the level of the pipe 24, and circulation is maintained in the boiler system thus formed from the drum 22 through pipe 26, header 20, tubes 14, header 18, and thence through the pipe 24 back to the drum 22. The water, while passing through the tubes 14, is wholly or partially converted into'steam which issues from the drum 22 through a pipe 28.

' The hot gases resulting from the combustion in the fire chamber 2 rise about the tubes 14 and are caused to pass first upwardly around all of. the tubes by a baflle upstanding from the bridge wall 6 and then downwardly by a baffle 32 depending from the top wall of the furnace. The gases then flow upwardly again to a flue 34 which conducts them into a breaching 36 leading to an economizer 38.

The parts thus far described constitute in themselves no part of the present invention. A more complete description of them is, therefore, deemed unnecessary.

In order to adapt the furnace to burn gas in place of or in addition to solid fuel when gas can be advantageously procured, the bridge wall 6 is formed with burner openings 40 located in a. horizontal row above the adjacent end of the grate 8. As shown, the openings 40 (Fig. 2) are of rectangular form, and each of them is provided with three gas burners, of which two are located on one side of the burner opening and the third on the opposite side. Manifestly, however, the number and arrangement of the gas burners in the burner openings40 of the bridge wall 6 may be varied without departing from the scope of the invention so long as a sufficient number of vertically spaced burner are provided to distribute the gas combustion uniformly throughout the openings 40.

On account of the high flame propagation of coke oven gas, when such gas is burned in the furnace, the combustion of the gas is practically complete before it passes from the fire chamber 2, so that substantially no combustion takes place in the space occupied by the Water tubes 14. 7

Moreover, the greater part of the combustion takes place close to the burner openings in the bridge wall 6. The front wall 4 and the greater part of the bridge wall 6 of the furnace are composed of refractory material such, for example, as high grade fire brick. In order. however, to enable the bridge wall without disintegration to sus tain the intense heat generated adjacent to the burner openings, the face of the wall on the side toward the fire chamber 2 is lined with blocks made from carborundum or other material of special refractory quality. In the illustrated construction, the lining blocks are denoted by heavy lines where they appear in section on the drawings. These blocks cover the bridge wall 6 between the openlngs 40 as indicated at 42, Fig. 2) and are also located above and below the openings 40 as shown at 44 and 46 (Fig. 1). The vertical sides of the openings 40 are covered with lining blocks in zones extending for some distance back from the fire chamber 2. Theblocks designated 48 and 50 in Fig. 1 are special refractories, as are also the blocks which intervene between them along the side of the burner opening. 1

The gas burners are preferably arranged to deliver gas to the openings 40 atpoints adjacent to the fire chamber 2. When coke oven gas is used in the furnace, the flame of the burning gas, due to its high flame propagation extends back into substantial contact with'the burners. As a consequence, burn ers of usual construction, for example, metal burners, cannot be used in a furnace for burning such gas in-large quantities since the burners would quickly become overheated and burned out. The burners 52 of this invention are particularlydesigned for use in burnlng gases of high flame propagation,

and, to this end, they are formed of blocks. of CZII'bOIUIlClIlHl'jOI' other special refractory material. As shown, each of theburners 52,

is formedwith a passage for gas having a straight main portion 54 leading from one of its endsto a point adjacent to' its other end and a short laterallycleflected portion 56 leading from the portion 54 to one side of the block and opening out of the 'side of the block at-a point adjacent to its other end.

The blocks 52are setjinto the bridge wall 6 around the openings 40, andare so arranged that the sides of the blocks containing the laterally deflected portions56 of the gaspassages form part of the inner surfaces of the burner openings 40. The ends of the'blo'cks 52adjacent to the portions 56 of the gas passages are spaced from the fire chamber '2 by lining blocks 58 so'that vthe burner blocks 52are caused'to deliver gas directly to the burner openings 40 of the bridge wall 6 at points spaced by a short distance from the fire chamber 2. 1 V

The arrangement of the gas burner blocks 52 relatively to the lini'ngblock's 4. 8, and 58 and the blocksintervening between them jacent ends of the openings 40 of the bridge wall. The flame of the'gas extends back in the openings. -10 substantially to the plane of the mouths of the. portions 56 of the passages of the burners 52.

a conduit 60 located in the space between the bridge wall 6 and the rear wall 16.

It is found in the use of gas furnaces that;

greater heating value in relation to the amount of gas consumed is obtained by shuts ting off some of the burners when it is deburners are operated at. rates which allow the greatest degree'of efficiency tobe attained, the burners 52 are supplied from the conduit 60 by individual pipes 62, each of which is provided with a valve 64, and the rear wall 16 of the furnace is located at a distance from the bridge wall suflicient to allow an operative to pass between them, thus afiording access to the valves 64 so that the supply of gas to the'burner openings can be separately and independently controlled. The valves 64arelocated in verticalportions 65 of the pipeswhich form angles with horizontal portions 66.) The portions 66 of "the pipes in turn have their endssealed into the passages 54c of the burners 52 as shown in Fig. 6. The end wall of the space between the bridgelwall-6 and the rear wall 16 may be provided with a door 67, and a roof 68 intervening between the walls 6 and 16 prevents'soot from. bein deposited between the walls. I

' The introduction of air to the burner openings 40, is regulated by doors 69 hinged vertically on'rods 70 (Fig. 2). The doors 69 maybe retained in any'desired position of adjustment by latches 7 2 co-acting with serrations/Z4 (Fig. 5) on a semi-circular segment bar 7 6 located at the bottom of each of the burner openings 40. To the end that aplentifulsupply of air'may be afforded to the burner-openings 40 and the space between the walls maintained relatively cool, the rearwall 16 is formed so that a large partof its area isopen. In the illustrated construction, this is etfected'by providing it with large openings 7 8 (Figs. 2 and 3).

Burners of the type heretofore employed in gas furnaces cannot practically be used for burning coke oven gas for the further reason thah 'due to its high flame propagation, theflameof'the gas would flare back in the burnersQTh'e' flaringback of the flame can be largely avoided in the use of thepresent construction by reason of the ease and. precision with which the supply of gas and air-to the burners can be regulated by the valves'6 t and hinged doors 69.

difficulty was 'at first experienced in properly controlling the flame so that itwould .not flare back. This difficulty was obviated Gas is supplied to the burners 52 from by filling in the burner openings 40 adjacent In spite, however, of such capacity of regulation, some to the doors 69 witha chec'kerwork 80 of fire brick, thereby increasing the efiective Velocity of the airas it'reaches the burners. With this j Y burnersj52. sired to reduce the heat of the furnace, than byfdecreasing the supply ofgas ,to all of them. In the illustrated construction, in order that the supply of gas may be shut oafrom some of the burners while the other zontal portions 66=of the pipes 62 in line with the vertical portions 65,. The extensions 82 are provided at their upperends with valve casings 84' which are open to the air at 86.

The valve'casings 84; carry valves 88 which normally prevent the admission of air to.

4 the burner, the valve 88 may be opened to induce flow of air through the burner.

The invention having been fully described, what is claimed as new and is desired to be secured by Letters Patent of the United States is 1. In a furnace, a fire chamber having a wall formed to provide a series of openings uniformly spaced horizontally across the width of the chamber through which air may enter into said chamber, a plurality of vertically spaced burners mounted in each of said openings, means for individually controlling the respective burners from the outside of said chamber, and means for controlling the flow of air through the individual openings.

2. In a furnace, a member having a gas burner opening, hollow refractory blocks set in the member about the opening and operating as burners to conduct directly to the opening at points adjacent to one end of the opening, means for supplying gas to the blocks, and checkerwork adjacent to the other end of the opening for increasing the effective inlet velocity of the air through the opening to prevent the flame of the burning gas from back-firing.

In a furnace, a member having a gas burner opening, means for causing gas to be burned adjacent to one end of the opening,

checkerwork adjacent to the other end of the opening for increasing the effective inlet velocity of the air through the opening to prevent the flame of the burning gas from backfiring, and hinged doors at the last-mentioned end of the opening for adj nstably controlling the supply of air to the opening.

l. In a furnace, a fir .chamber having a wall formed to provide a series of openings spacedhorizontally and through which air may enter into said chamber, a plurality of vertically spaced gas conduits adapted to deliver combustible gas into each of said openings, means whereby the effective velocity of air is increased near the point at which it entcrs each of said openings, means for individually controlling the respective gas delivery conduits from the outside of said chamber, and means for controlling the flow of air through the individual openings.

5. In a furnace, a wall having a plurality of burner openings therein, a plurality of nortsfor delivering gas to each of said openings, means whereby air is supplied to said openings for supporting combustion, individual pipes for supplying gas to said ports, control valves in said pipes, and valved connections to each pipe in the port side of said 'alves whereby the suction in the furnace may draw cooling air through said burners when the corresponding control valves are closed and the second mentioned valves are opened.

6. In a furnace, a refractory wall forming one side of a fire chamber for said furnace, a series of burner conduits extending through said wall and ada tedto project flame into said chamber, a higher refractory lining in the outlet ends of said conduits and on the chamber side of said wall adjacent said conduits, a plurality of combustion gas outlet ports in the inner surface of each conduit in the higher refractory lining therein, and adjustable closure means for each conduit at the end remote from said chamber for admitting air for combustion.

7. In a furnace structure, a burner for supplying hot products of combustion thereto, which comprises a conduitopening into said furnace through which burning gases are adapted to be delivered, means for admitting air to said conduit, means for introducing combustible gas into the said conduit at a plurality of points through ports in the inner surface of said'conduit near the discharge end thereof, said last mentioned means comprising refractory blocks having gas passages therein, said blocks being mounted in the wall of said conduit, and means for conducting combustible gas to the passages in said blocks.

8. A furnace, comprising refractory walls forming a fire chamber, a channel through one of said walls comprising a burner for pro jecting a flame into'said chamber, gas delivery ports in the inner surface of said channel near the channel outlet to said chamber, means for delivering combustible gas to said ports, and an adjustable closure for'the end of said channel remote from said chamber for the admission and control of air for burning the gas introduced near the outlet end of said channel.

In testimony whereof I afiix my signature.

JOHN FRANCIS OCONNOR.

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