US1349790A - Fuel-burner - Google Patents

Description

J. R. SMITH. FUEL BURNER. APPLICATION FILED rams, 1918.

1,349,790. Patented Aug. 17, 1920 2 SHEETS-SHEET l- OOOOOOOO O0 I m [Iv C J. R. SMITH. FUEL BURNER. APPL-ICATION mm FEB. 18, I916.

Patented Aug. 17, 1920 ax g 2 SHEETS-SHEET 2.

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of such ash and clinkers.

UNITED STATES 551cm OFFICE.

JAMES B. SMITH, 0F MECHANICSVILLE, NEW YORK.

FUEL-BURNER.

Specification of Letters Patent. Patented A 0; 1 7 1920 Application filed February 18, 1918. Serial No. 217,949.

To all whom it may concern:

Be it known that I, JAMES R. SMITH, a citizen of the United States, residin at Mechanicsville, county of baratoga, btate of New York, have invented certain new and useful Improvements in Fuel-Burners, of which the following is a specification.

This invention relates to low grade fuel burners.

The object of the present invention is the provision of a novel air blast burner for heaters and steam boiler furnaces which will be adapted for use with low grade fuels such as coal dust, screenings, barley, birdseye and, in fact, all of the small grades of anthracite and bituminous coals, at half the cost of lump coal. I

In the burning of fine fuel, special pinhole plates or line slotted grates are usually employed, and with the larger sizes of fuel the usual shaking or rocking grates are used. Both forms of grates are an expensive item, if neglected, to replace. Furthermore, ordinary grates and chimney draft cause undue fuel consumption, over-heating in the early fall and spring and, despite regulation, air leakage and resulting draft, causes great waste of fuel; furthermore, a very large percentage of combustiliile mate rial is shaken down into the ash pit when ordinary grates are used.

My present improvements eliminate the foregoing effects and wastes incident to the use of ordinary grates and enable low grade fuels to be used with a maximum release of thermal units, minimumv of ash residue re quiring removal, and lessening of the labor and attention required. i

In carrying out the invention, there is provided a fuel support which is sealed from the ash pit except for means for dumping the ash and clinkers at those times when the fuel support requires the elimination ()ne ormore burners or air blast boxes of novel construction and adaptation for the delivery of the air blast in a semilateral manner, say about 45 degrees, into the fuel, constitutes the means for supplying oxygen to the fuel. The air is supplied under pressure to the burner or burners. The discharge openings in the burners change the pressure into a volume of air which is directed upon the fuel support and reboundsor reacts in a general upward direction into the fuel bed, developing intense combustion and being disseminated throughout the fuel. When the blast is shut off the fire lies substantially dormant with no appreciable fuel consumption, but consumption begins when the blast is renewed. The blast is automatically controlled, by preference, by the steam pressure. For instance, an electrically driven blast fan is used for supplving the blast to the burner or burners, and the driving of the fan is under the control of an electric switch which is opened and closed in response to the operation of a steam actuated regulator subject to steam derived from the boiler.

One or more dump openings are provided 111 the fuel support, normally closed by slidable dump-closures. hen said closures are opened, the waste and clinkers fall into the ash pit. W hen the ash pit is cleaned, only the clinker will be thrown away, the other residue being again, fed into the furnace for consun'iption.

The burner or blast box and the semi-lateral discharge of the air into the fuel and its rebounding from the fuel support, and from the fuel itself, in iwardly through the fuel bed, constitute important features of the invention, including the transformation of the pressure within the burner, to volume, with reduced pressure, where the blast dis charges into the fuel. The blast boxes serve to preheat the air before it is discharged into the fuel. I D

The embodiment of the invention hereinafter described and shown in the accompanying drawings is susceptible of modification without departing from the essential principle thereof and it is to be considered. as illustrative, rather than restrictive, of the scope of the invention.

In the accompanying drawings,

Figure 1 is a vertical section showing the invention applied to a steam boiler Fig. 2, a front elevation, the boiler setting being broken away and the shell of the blast fan being in section;

Fig. 3, a horizontal section or plan of the fuel support, burners, and dumps;

Fig. 4, a longitudinal section on the line a e of Fig. 3; I I

Fig. 5, a cross section on the line 55 of Fig. 3;

Fig. 6, a detail cross section of one of the burners; and

Fig. 7, a detail side elevation of one of the dumps.

holes 14 in the flanges 12.

The invention is illustrated in connection with a steam boiler but it may be used on any type of furnace, heater, or fire box.

The boiler appears at l, the brick setting at 2, fire box doors at 3 and ash pit doors at a. My invention is substituted for the usual grates and it directly supports the fuel.

The fuel support 5 is in the form of a horizontal tray having a side wall 6 extending on the four sides thereof and being provided with legs 7 which rest on the boiler foundation. The fuel support 5 fills the space usually occupied by grates and is preferably sealed therein so that there will be substantially no draft or air leakage from the ash pit 8 upwardly into the [ire box 9. Extending lengthwise of the .fuel support are one or more burners or blast boxes 10 which are preferably made separate from the fuel support, as shown in Fig. 6, and fit snugly into longitudinal slots 11 and are provided with longitudinal flanges 12 which are bolted at 13 to the fuel support 5, the bolts passing through As thus constructed and arranged, the burners or blast boxes have part of their height above the fuel support 5 and part therebelow. I do not limit the burners or blast boxes to this arrangement and construction nor to the rectangular or square cross sectional shape shown. The blast boxes or burners extend for as much of the length of the fuel support 5, from front to rear thereof, as may be desired; they are shown as extending from points somewhat back of the front end of the fuel support, to the extreme rear end'of said fuel support. The bu ners or blast boxes 10 are provided with semi-lateral discharge openings 15 on opposite sides thereof. As shown, these openings are continuous longitudinal slots running from one end of the burner to the other end thereof, but they could be composed of a plurality of slots or openings although the best results are obtained by having them substan tially continuous so that a sheet of air will .be delivered from each side of the burner or box. In practice the openings or slots 15 are substantially at an angleof 45 degrees to the horizontal plane of the fuel support 5, but it is not essential to dispose them at that angle, the object being to have them direct the discharge of air in a semi-lateral direction, that is, at a point or angle between a horizontal and a vertical plane, so that the air will be discharged in a general downward direction into the fuel and will rebound or react upwardly into the fuel bed, thereby becoming thoroughly disseminated throughout the fuel and coming in contact with the fine particles thereof.

I prefer to form the slots 15 by providing a removable cover or top 16 for the burner 10, said cover having depending llangcs l? at its ends which overlap and rest upon the ends of the box 1o at 18, Fig. l, the longitudinal sides 19 of the cover being provided with inclined under faces 2i), and the upper longitudinal edges of the sides of the box 10 being beveled at 21. (ross ribs 16 on the under 'l'zn'e o i the cover support it above the box 10, thus defining the slots 15. The slots 15 are arranged at an angle of about 4-5 degrees to the fuel support 5. The covers 16 of the burners or boxcs Ill support the fuel which lies above said boxes and prevent it from getting inside of the boxes. ll. will be understood. however. that the boxes 10 are buried in the fuel supported by the fuel support 5. and that the boat from the fuel, radiated through the covers 16, prchoats the air in said boxes prior to its (lifir'iiill'g'l through the slots 15, thus increasing the eliiciency of the air blast. The covers [(3 are secured on the boxes l0 by bolts .10 (liig. o) passing through holes in the cover and the bottom of the box and having polygonal heads 10" seated in, and fitting, countersinlis 10 so that said bolts will not turn. The bolts are packed with asbcsti'is Ill where they pass through the bottoms of the boars 10 so that the nuts .10 will not be allowied by the excessive heat. (onscipicntly the nuts 10 can be readily removed from the bolts whenever it is desired to ren'iove the covers 16 as. for instance, when the covers burn out. To substitute now covers 1b, it is only necessary to remove the nuts 10" as the boxes 10 need not be disturbed. Being romovable, the covers 1G enable access to be had to the interiors of the boxes.

in air blast fan 22, which is suitably inclosed in a casing 23 outside the furnace, supplies the burners or boxes 10 with air, through a pipe whose branches 25 enter the bottoms of the boxes 10. The fan 22 is driven by an electric motor 26 also contained within the casing 28. An electric switch of a well-known type controls the circuit leading to the motor 26, said switch being adapted to close and 0 ion by the following control. The switch comprises a rockable switch arm 27 mounted on a pivot 27 and. adapted to be quickly opened or closed by a. flop over weighted lever 27" which is adapted to be moved past vertical position to the right or left, Fig. 2. by an arm 27, also mounted, on pivot 27. The switch arm 27, lever 27, and arm 2T are loosely mounted in relation to each other on pivot 27. lVhen the arm 27 has moved le ver 27* past the vertical position, the lever flops over by its own weight and opens or closes the switch arm 2?, as the case may be, holding the switch arm in closed or open p0 sition until a reverse movement of arm 27 occurs. A steam-actuatcd regulator 28, deriving steam from the boiler by pipe 251, is

'ill

connected to the arm E27 by a chain 30 from which is suspended a weight 31. The arm 27 is thus positively moved up or down, according as the steam pressure rises or falls. The regulator 29 may be set to operate at any desired pressure. When that pressure is reached, the regulator lever pulls upon the chain 30 and opens the switch. When the pressure falls, the weight 31 closes the switch. The motor 26 is thus started when the pressure falls and stopped when it rises beyond the predetermined point. Consequently when the pressure is below the predetermined point, the air blown into the burners 10 is delivered in volume, at reduced pressure, through the slots 15, thus causing the fuel to burn and the pressure to rise until the predetermined point is reached, whereupon the switch is opened and the blast stops. When there is no blast, the fire is substantially dormant and little or no fuel consumption takes place until the blast is resumed.

At the front ends of the burners are open frames 32 constituting clinker and ash dumps. These have flanges .33 fastened at an to the support 5 and are provided with inclined lower edges 35. Angle-iron guides 36 which are fastened to the sides of the frames 32 at 37 extend forwardly from the frames toward the ash pit doors 4. Slidable on the horizontal parts of the angle-iron guides 36 are closures 38 which have inclined upper faces 39 adapted to wedge snugly against the inclined edges to effect a tight closure of the frames 32. Pull rods 40 connected to the closures 38 enable the latter to be opened or closed, on opening the ash pit doors 4.

llinkers and ash residue can be drawn forward on the fuel support 5 and dropped through the frames 32 into the ash pit. The clinkers may be removed but as the ash residue contains unconsumed fuel, it may be again thrown on the fuel bed for consumption.

WVhat I claim is:

1. A fuel burner embodying the combination of a sealed fuel support, and an air blast feeder having means for discharging the air from points above the fuel support in a general downward direction into the fuel and onto the fuel support to cause reboulnding of the air upwardly through the fue 2. A. fuel burner embodying the combination of a sealed fuel support, and an air blast box whose walls rise from the fuel support and are provided with openings located above the fuel support arranged for discharging the air in a general downward direction into the fuel and onto the fuel support to cause rebounding of the air upwardly through the fuel.

3. A fuel burner embodying the combination of a sealed fuel support, and an air blast box having a top or cover and Walls which rise from the fuel support and are pro vided with openings located above the fuel support arranged for discharging the air in a generaldownward direction into the fuel and onto the fuel. support to cause rebounding of the air upwardly through the fuel, and means for discharging air under pressure upwardly into the box and against the cover thereof.

In testimony whereof, I hereunto afiix my signature.

JAMES B. SMITH.

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