US886261A - Furnace. - Google Patents

Description

'PATENTED APR. 28; 1908 0. W. sMiTH. FURNACE. APPLICATION FILED 1130.29. 1905.

2 SHEETSSHBET 1 UNITED STATES CLARENCE W. SMITH,OF CAMBRIDGE, MASSACHUSETTS.

FURNACE.

Application filed December 28, 1905. Serial No. 293,577.

To all whom it may concern:

Be it known that I, CLARENCE W. SMITH, of Cambridge, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Furnaces, of which the following is a specificatron.

My invention relates to-furnacesand more particularly to those applicable to steam oilers. Its rincipal object is to provide a furnace .Whic 'will attain a high degree of efiiciency .in the consum tion of varying grades of fuel. To accomplish this, the exact amount of air required for perfect combustion should be presented to the burning fuel, since too little will result in a deadening of the fire, and waste from partly burned gases, and an excess means the lowering of the the box temperature, waste of fuel in heating needless air and the, overloading of the stack.

The air must also be uniforrnl diffused through the ash-pit, otherwise loweholes will be made in the burning fuel, causing wasteful excess of air and the formation of clinker and sla from the intense local action. These desirab e results mentioned, which have been heretofore imperfectly attained in' plants using forced or induced draft, are secured by my invention.

In the accompanying drawings, in which similar characters designate like parts i througlhout'the several views-Figure 1' is a contra vertical longitudinal section through a boiler and its furnace, embodying one form of my invention. Fig. 2 is a transverse vertical section therethrou h, and Fig. 3 is a sectional detail through t e outlet openings in the top of the bridge-wall.

The furnace 10, as here shown, is formed in the masonry inclosing a boiler 11. It comprises a grate'12 supported between the front of the structure and a bridge-wall 13, and has beneath it an ash-pit 14. Extending throu h the bridge-wall in a gcnerally'horizonta direction, and opening into the ash-pit beneath the grate is a passage or conduit 15. Above this passage a second passage 16, or a plurality thereof, as is shown in the present instance, opens from the ash-pit extending through the bridge wall, first in a horizontal direction and then vertically, diverging upwardly to a considerable number of corn tractod openings 17. These may be formed of fire-resisting tile 18 in a recess at the top of the bridge wall so that their" tops are flush with the top of the bridge-wallf The Specification of Letters Patent.

Patented April 28, 1808.

o epings 17 are preferably tapered, having t on minimum diameter at the upper ends. Between the openings of the passages 15 and 16 is situated a deflector 19, which 1s inclined downwardly from the grate, across the end of the former passage. The deflector may be curved, as 1 lustrated, its convex side being outward.

or condu it 20 lying across the furnace and being continued outside the casing by. a. pipe 21, leading to the movable air-supplying ,arm 28 and a bevel pinion 29 which meshes with a bevel gear 30 fast upon a shaft 31. This shaft has secured at its oppositccx tremity a crank-disk 32, the pin of which is connected with some convenient form of ressure-regulating device 34, joined to the su ply under pressure by pipe 36.

n using my im roved furnace, air is drawn by the fan t trough the pipe 23 and forced into the passage 15in the'bridge-wall against the curved deflector, by which it is directed against the lloor of the ash-pit, over which it flows and rises in equal di'l'l'usion through all arts of the grate. The dcflector extending the full width of the firebox effectually prevents the escape upward of air at the sides of the pussuge 15, with consequent excess of draft and blow-holes in .the fuel at that end of the grate. A part of the air )asses into the passugo l6 and delivered by the contracted openings into gases trm'eling over the lu'idgwwnll. The taper of these-o innings prevents the :u-r-umulation of ash, While their reduced outlets give the ejected. air a high velocity and penetrating power, intimately mingling it with the gases oven at the ends of the will when the spaces between it and the shell of the boiled are 1 widest. The secondary air-simply, antrol l -ducou abo\ e the let-cl oi the top of fucl Atthe rear of the bridge-Wall is a chamber.

means which is shown as a blower 22, having.

trolling the motor speed. The spindle 27 of the rheostat has fixed to it the usual contact- Joiler by pipe 35, and to a source of water which isressential for complete combustion. of thcvalnable gases distilled oil and the pre vention of smoke, is" thus provided. ".lhe' air after being warmed in the pipe 23 and con duits 20 and is spread under the grate by the deflector l9 and heated there, and then the air which returns into the bridgeavall on its-way to the contracted openings 17 is highly heated before issuing through said openings. If the pressure in the boiler varies from the desired amount, the reg ulator automatically shifts the contact-arm of the rheostat, thus varying the current delivered to the motor to increase or decrease its speed and that ohthefan, thus increasing or decreasing the volume of the airidelivered to the furnace as ma "be necessary. The

regulat onpfa r supp 'y to the furnace ands consequent steam pressure iii the boiler cfsupply ofhir from that heated by 'fected by this arrangement is very erfect,

but'little resistance being offered by t is contact-arm. to'its moveinent by the, pressure regulator. And as the contact'blocks and connected resistance *coilsare numerous, a high degree of sensitiveness is attained. This automatic control of the air-supply and the diffusion'of air through the bed of fuel and through the escapin In drawing the the boiler, it 15 not only delivered to the fire at a tornperaturc raised to an effective degree, but the boiler-rodm is also rendered more com-- it practih lly smolieless;

fortable by the withdrawal ofthe hot air.

Though Lhave described my invention as ap lied to a steam boiler satin masonry, it will be seen that it is by no means limited to such an application, but that it may be used in connection with-furnaces of many types.

I claim: I

1. A furnace comprising a grate, a bridgewall provided with a assage terminating'in a series of contracts openings in its upper portion said passage openin beneath the grate and a second passage a so opening beneath the grate, means for forcing air to the space beneath the grate, means for distiibut 'ing the air beneath the grate, and automatic means for governing the air-forcing means responsive to variations of boiler pressure.

2. A furnace comprising a grate, a bridgewall provided with a passage terminating in a series of contractedopemngs at its upper portion and a second passage extending through the bridge-wall, both of said passages opening beneath the grate, means for forcing air to the space beneath the grate, a deflector situated between the passage openings and. inclined downwardly from the grate, and automatic means for governing the air forcing means responsive to variations of boiler pressure.

3, A furnace comprising a grate, a bridgegagscs, renders e hre necessary,

said passages, sai

recess and a second through thebridgewall, both of said passages opening beneath the grate, means for forcingair to the space beneath His. grate, a deflector situated between the passage-openings, and automatic means forgovernlng the air-forcing means responsive to variations of boiler pressure;

4. A furnace comprising a grate, a bridgewall provided with a passage terminatirn in a r fess, fire-resisting tile formed wit a series of contracted openings and set in said recess, "and a second passage extending through the bridge-wall, both of said passages opening beneath the grate, means for forcing air to he s ace beneath the grate, at deflector situated lietween the assage openings and inclined downwar y from the grate, and'automatic means for governing the air-forcing means responsive to vsriar tions of boiler pressure.

5. A furnace comprising a grate, a bridgei Wall provided with a assage ternunating in a series of contracts openings in its upper portion and. a second passage extending through the bridgeavall, both of said pas sages o ening beneath the grate, a deflector situate between the passage openings, and. means for supplyin air under pressure to blower, a motor for operating the lower, a rheostat for controlling the motor, a ressure regulator connected with 'the boi er, and means for communicating movement from the regulator to the rheostat.

6. A furnace comprising a grate, a bridgewall provided with a passage terminating in means com rising a inc a recess, fire-resisting tile formed with." a,

series of contracted openings and sct'in said passage extending through the bridge-wall, both of saidpassages o ening beneath the grate, a'deflcctor situate between the passage openings and inclined downwardly from the grate, and. means for supplyin air under pressure to,

said passages, sai means com rising a blower, a motor for operating thelh rheostat for controlling the motor, a pressure regulator connected with the boiler, and means for communicating movement of the regulator to the rheostat.

. The combination with a boiler furnace lower, a

having a grate, of means for forcing air into the'furnace independently of fuel su plied thereto, an electric motor for driving tlib airforcing means, a rheos'tat connected with the motor, a pressure regulator associated with the-boiler and mechanical connections be-- tween the pressure regulator and rheostat whereby the air supply is governed in accordance with. the amount of steam required,

and definite rates of combustion produced with an indeterminate fuel supply, said air forcing means having provisions for introducing air to the furnace both below and above the grate.

8. The combination of a boiler, a combusj tion chamber, means-independent of fuelsupplying means for forcingair into said (JOIHbUStlOII chamber, including an electric motor controlled by conditions within the 1* *ellected without regard to damper regulation of the escape of the products of combustion.

S). The combination with a boiler furnace having a grate, of means for forcing air in to the furnace independent of fuel supplied thereto, an electric motor'for drivirng the air forcing n'ieans, a rheostat connected with. the motor, a regulator associated with the boiler, and connections between the'regulator and rheostat, whereby the air supply is governed in accordance with the amount of steam required, and definite rates of combustion produced with an indeterminate fuel supply, the furnace having a free outlet for the products of combustion, the capacity of which is not affected bythe operation of the motor, where- (by the motor is utilized so that substantially all the air for combustion-is introduced and controlled by the motor for supplying air to the furnace. I

10. The combination with aboiler furnace having a grate, of-m'eans for forcing air into the furnace independent of fuel supplied thereto, an electric motor for driving the airforcing means, a rheostat connected with the a motor, a pressure regulator associated with the boiler, and mechanical connections between the pressure regulator and rheostat, whereby the air supply is governed in accordance with the amount of steam required,

, and 'delinite rates of combustion produced with an indeterminate fuel supply, the furnace-having a free outlet for the roducts of combustion, the capacity of whic is not affected by the operation of the motor, whereby the motor is utilized so that substantially all the air for combustion is introduced and controlled'by the motor for supplying air to the furnace.

In testimony whereof I. have atlixed my signature, in presence of two witnesses.

. CLARENCE W SMITH. \Yitnesses: J

FRED. W. SMITH: SIDNEY SMITH.

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