US1772896A - Furnace - Google Patents

Description

Patented Aug. 12, 1930 ATES PATENTy OFFME ROBERT A. ILG, OF CHICAGO, ILLINOIS ,FURNACE Vrlhis invention relates to furnaces, and the present application constitutes a Vdivision of an application heretofore hled by me on the 28th day of October, 1926, Serial No. 144,673,

Patent No. 1,674,828.

.The furnace of thepresent invention `employs a furnace grate of the movable endless chain type, which facilitates filling the front end of the fire chamber with coal by permitting .the fire .door :to be located at a relatively low point and also facilitates the discharge of theashes at the rear end of the grate by automatically dumping .the `saine into a receptacle removable and replaceable through a door in the rear wall `of .the furnace; and .one object ofthe present invention' isto provide improved means for .actuating the endless chain grate from a point outside the furnace. vAnother object is to provide improved grate ace tuating means which will permit the grate and its support tobe withdrawn through the rear of the furnace and subsequently replaced in working position without requiring any preliminary disconnecting of the grate actuaiting mechanism.

Other objects and attendant advantages of the invention will be apparent to persons skilled in the art as the same-becomes better understood by referenceto the yfollowing de tailed description, taken infconnection with the accompanying drawings wherein I have illustrated a practical and ecient .embodiment of the principle of the invention, and in which- 'and partly in vertical section, of my improved furnace; A

2 is a front elevation of the same;

3 is a rear elevation thereof;

Fig. 4 isa vertical longitudinal section taken on the staggered line 4-4 of Fig. A2 parts at the front of they furnace being omitted;

Fig. 5 is a vertical transverse section taken von the line 5--5 of Fig; 1;

Fig. 6 is a. vertical longitudinal section taken on the staggered yline 6-6 of Fig. 2 parts at the front of the furnace being Iomitted. Y

Referring to the drawings, 10 designates Fig. 1 is a view, partly in side elevation Divided and this application filed March as an entirety a rectangular sheet-metal housing or casing constituting the outer shell of the furnace structure and equipped with a front wall, the upper portion 11 of which may be of sheet steel or cast iron, while the lower portion 12 is preferably constructed of cast iron to support the lire and draft doors, the operating mechanism of the grate, and the cooling chamber.

Located centrally within and extending lengthwise of the lower portion ofthe shell or casing 10 is the combustion chamber yor lire box 13 of the furnace. This is a relatively narrow long structure, preferably formed with a rounded or dome-shaped top as shown in Fig. 5, with its rear end registering with an opening in the rear wall of the housing normally closed by a door 14 (Fig. 3). On the bottom wall of the combustion chamber are track rails 15 accommodating the wheels of a removable truck 16 on which is mounted a fuel grate 17 of the well-known endless link chain type mounted and supported on front and rear sprocket wheels 19 and 2O respectively. The grate is inclined upwardly from its forward to its rear end, the forward end being but a slight distance above the floor of the ash pit, while its rear endis suiiiciently elevated to enable the ashes to be discharged into a removable ash can 21 locatedjbeneath the yrear end of the grate just inside the rear door 14. This provides ample air space below the grate, and at the same time permits` the frontdoor 22 of the combustion chamber to be located at arelatively low point lin the front wall of the fur-nace, thus facilitating firing. f

Attached to or cast integral with the 'lower portion l2 of the front wall and surrounding the opening yguarded by vthe door 22 is a hollow casting` 23 adapted to contain water; the lower limb of said casting preferably eX tending inwardly as shown at 23 above the lower front portion of the kgrat-e and serving as a baille to prevent the body of coal on the latter from clogging between the front wall and the front end of the grate. Water may be supplied to this jacket through a pipe 24; and, where said acket is used as a hot water heater, the jacket' may be additionally prorided with an outflow pipe 9: which, with the pipe Q41-, may be connected into a suitable water tank. In the event that the water in the jacket 23 is used 'for humidifying the air, the pipe 25 may lead into one of the heated air passages the furnace at any convenient point. rl`his water jacket also serves to maintain a relatively low tempera ture of the front wall of the lire chamber, preventing waste of heat through radiation from the latter. The grate is moved to carry the body of burning coal rearwardly and upwardly from time to time as fresh firing is required by a simple foot-operated actuating mechanism herein shown as comprisinj;l gear wheel Q5 f it on the shaft of the lower grate sprocket `wheel i9, a pinion 2"? meshinej with said gear wheel L``nd fast on a shaft 28 journaled in the side walls of a suitable casing` 29 mounted on the front wall, a ratchet wheel 8O fast on sbl it 28, and pedal lever 31 carrying a pawi 82 engaged with the ratchet wheel 30. The -",edal lever 3l is depressed by the foot to actuate the f ato, and. is returned to neri al d position by a elevate` )ull s )rino At the l ttom of the front l e in which is mount- OO wall is a cleanout door ed the usual dra The furnace is so con" Ypairof symmeti" relativ y loneT passages for the flow of the hot products of combustion to the sinel flue at the top of the furnace, together with a damper-controlled by-pass which may be employed to shorten the outflow passage when tiring up, or when a rapid increase in heat is desired; and also 'with a symmetrical pair of rela` tively lone; flow passe for the air to be heated said air passages being so arr-a1 ged. that the walls of the ano smoke pac,.. ges will be efficiently bathed by the air and the heat abstracted therefrom and transmitted to the air.

YWithin the outer sl ell or housing 10 and encldsingr the major portion of the top and sides of the lire bon 13 is a gelerally rectangular inner sheet-metal as to provide hood-like structure eon'iprisine a top wall 3G spaced from the top wall of the housing` l0, .side walls 37 parallel with and spaced from the side walls of the housing and terminatingl slightly above the bottom wall of the latter, and a rear wall 3S. As best shown in Fir fl, .5 and G, the upper portion of this hood is subl divided by suitable partitions to provide draft flues for the products of combustion and alsov a central rtical flue for the out- ,39 designatos each of a pair of longitudinal partitions, and l0 and ill G) pair of transverse partitions between 'the longitudinal partitions These partitions, with a portion ofthe rear wall 38 and the upper portion l1 of the front wall of the outer casing together form a central outflow passage or flue vdiating tins 60.

for the heated air communieating` with a flue section l2 in the top wall of the casing, to which latter is connected the warm air pipe or pipes leading to the registers. fs/here artificial circulation of the air is employed, an opening is provided in the upper portion of the rear wall of the cater casing, in which is mounted a frame i3 supporting an electric motor lll operating a direct driven fan 45, which forces the return air into the space between the outer and inner casings. This airfloods tbe space between the top w; ls Y the casings, flows Y thence downwardly through the spaces between the side walls, thence upwardly between the side walls of the inner casing and the side walls of tile fire box, and thence upwardly through the warm air flue formed by the par 'tions 39, l0 and lll, the rear vwall 38 of the inner casing and the front wall ll of the outer casina` Between the longitudinal partitions 39 and extending from the lower edge of the transverse partition s() to the rear wall 38 is a horizontal plate L6 (F ig. and similarly positioned between the longitudinal partitions 39 and extending from the upper edge of the transverse partition Lll to the rear wall S8 is a horizontal plate 1l?. These plates are apertured, and fitted between them is a shortby-pass flue section a9, rlhe upper and lower rectangular chambers thus formed communicate through upper and lower ports and 51 respectively with longitudinally extending side flues formed between the longitudinal partitions and the side walls 3T `of the hood. The bottoms of these side flues are closed by horizontal plates 52; and the rear bottom and top portions of the space between said side flues are closed by a horizontal plate 53 and the central longitudinal portion of the top wall 36, the former of which is apertured to receive the upper end of a short flue section 55 mounted on and communicating with the combustion chamber 13, while the latter is apertured to receive a smoke discharge flue 56. Attached to the rear wall of each of the side fines between the upper and lower ports 50 and 5l isa longitudinally extending baille plate 57 that is preferably forwardly and downwardly inclined, as shown in Fig. et; and within the flue section t9 is a pivoted damper 5S mounted on an operating rod 59 extending through the front wall of the furnace. r)The outer surfaces of the sidewalls 37 of the hood are preferably equipped with heat ra- On the front wall ofthe outercasing are cleanoat doors i3l normally closing the frontends of the side smoke lines. There the fan l5 is employed. to create 'au artificial circulation of the air, itv may be located, as shown in Fig. l, within the cold air return flue 62 which ordinarily commu# nicates with a grating in the floor of the room above the furnace. Fresh air may be lll permitted to the extent desired by providing on the side of the flue 62 an opening guarded by a pivoted wing valve or damper 63 which may be closed or opened more or less by a rod 64 which may extend to the room above. Automatic regulation of the temperature may, manifestly, be effected by actuating the valve G3 by a thermostat; said valve thus serving not only to admit fresh air when desired, but also, when thermostatically controlled, as an automatic temperature regulator.

The operation and advantages of the described furnace will it is believed be clear from the foregoing description of its structural features. The inclined chain grate provides increased space at the forward portion of the fire box for firing and makes it easy to lill the front portion ofthe grate with coal, since it permits the lire door to be located much closer to the floor line. rlhe elevation of the rear eno of the grate provides ample space for the location therebeneath of an ash receptacle for catching all of the spent material, reducing the frequency with which the liner portions of the ashes falling beneath the grate have to be removed. And the mounting of the grate on a truck bodily removable through a door opening in the rear wall of the furnace greatly facilitates cleaning, repairs and renewals when required and automatically brings the grateactuating gears 26 and 2'? into register when the grate is fully entered.

The provision of the water jacket around the fire door and above the lower end of the grate is valuable as maintaining` an even temperature in the front of the iire chamber and a lower temperature at the point where the new fueL is supplied tirough the fire door. This feature also performs the function of the usual hot water coil in supplying hot water for any purpose, while it may also, be used for humidifying the air passing through the furnace. ln lieu of employing water in the jacket for the purposes above-mentioned, the outlet pipe 25 may be left open, and the inlet pipe 2li may be connected to the rear part of the furnace where fresh air is introduced l j; the fan, creating a plenum condition. This will provide a natural cool air circulation which will function the same as the water in keeping down the temperature at the front of the fire chamber.

VEhe cool air, whether forced in by the fan, or flowing in by gravity, flows over the top and sides of the-inner shell, below the lower edges of the side walls of the latter, thence upwardly between said side walls and the sides and top of the fire chamber, and thence upwardly through the relatively large central air liu-e. clNith the damper 58 closed, smoke and hot gases of combustion flow from the fire bon through the short neck 55, thence A rthrough the lower portsl into the two side flues below the baffles 57, flowing forwardly beneath .the latter, thence around their Afront ends, thence rearwardly through the npper portions ofthe side fines, thence through the upper ports 550 into *the Idischarge flue :56. rlhe-wafll-s 36 and '37 of 'the :inner shell thus become highly heated through direct contact with the hot gases, and, since 1these walls are bathed by the vair flowing through the furnace, a very efficient heat exchange is .ef fected.

rThe use of ythin sheet-metal in the greater portion of the furnace structure lends itself to economy in production and superior :eiliciency in heatexchange yand whereempl-oyed in connection 'with artificial air circulation., as shown, increases the rapidity with whch the rooms served :by the furnace can be brought to a desired temperature.

vlll'lhile l have shown yand described any present improvements Vin association with a furnace vof .the hot air-type `which includes a heat exchange feature above the fire box, it is .to be vunderstood that Athe ,present im'- provements relate to the fire box and girate structure and are applicableto other types of furnaces, such as those used in .hot 'water and steam heating plants. lVhile l 'have herein shown and described one practical and eflicient embodiment of the principle of the invention, it is manifest that minor details of structure and arrangement mayT be resorted to without departing from the principle of the invention or sacrificing any of the benefits or advantages thereof. Hence, l do not limit the invention to the exact construction shown and described for purposes of illustration, but reserve all such variations, modications and mechanical equivalents as fall within the spirit and purview of the claims. f

l claim l. In a furnace, the combination with a combustion chamber having an opening in its rear wall, of track rails on the bottom of said chamber, a truck movable into and out of said chamber through said opening, on said rails, an upwardly and rearwardly inclined endless chain grate mounted on said truck, a door closing said opening, and gearing for actuating said grate mounted partly on the latter and partly on the front wall of said combustion chamber and adapted to be automatically coupled when said grate is fully entered into said combustion chamber.

2. In a furnace, the combination with a combustion chamber iaving an opening in its rear wall, of a frame in said chamber, front an d rear shafts ournaled in said frame, sprocket wheels on said shafts, an endless chain grate mounted on said sprocket wheels, a gea-r fast on said front shaft, a shaft journaled on the front wall of said combustion chamber, a pinion fast on said last-named shaft meshing with said gear, a ratchet on .ist

said last-named Shaft, a lever pivoted on said last-named shaft yand carrying a pawl co-operating with said ratchet, and a spring for effecting the idle movement of said lever.

3. In a furnace, the combination With a combustion chamber havingl an opening in its rear Wall, a truck movable into and out of said chamber through said opening, front and rear shafts journaled in said truck7 sprocket Wheels on said shafts, an endless chain grate mounted on said sprocket Wheels, a gear fast on said front shaft, a shaft onrnaled on the front Wall of said combustion chamber, a pinion fast on said last-nained shafts, means for turning said pinion, and track rails on the bottom of said combustion chamber for guiding said truck into the latter and bringing said gear and pinion into mesh.

4. In a "furnace, the combination with a combustion chamber havin@ an opening in its rear Wall, of a truck movable into and out of said chamber through said opening,

chain grate mounted on sa/id truck, a door closing Said opening, and a removable ash receptacle located below the elevated rear end of said grate.

ROBERT A. ILG.

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