Patented Aug. 31, 1909.
WITNESS 5 @Qi Danie Z L DANIEL L. BROWNFIELD, OF FARMER, WASHINGTON.
STEAM-BOILER FURNACE Application filed July 17, 1908.
Specification of Letters Patent.
Patented Aug. 31 1909.
Serial No. 444,007.
To all whom it "may concern:
Be it known that I, Dxxnn. L. lhawvxrinLo, citizen of the United States, residing at Farn'ier, in the county of Douglas and State of IVashington, have invented certain new and useful Improvements in Steam- Boile'r Furnaces, of which the following is a specification.
This invention relates to steam-boiler furnaces and more particularly one designed for burning straw.
The object of the present invention is to provide a furnace structure which will prevent the fire-box from filling with ashes, and also to prevent accumulation, such as ashes beneath the grate, and also to keep water on the crown sheet both down and up hill, thereby preventing the crown sheet from being burned while traveling on rolling land.
In the accompanying drawings, Figure l is a vertical sectional view of the boiler and furnace. Fig. 2 is a plan view. Fig. 3 is a plan view of the traveling grate.
Referring specifically to the drawing, 5 denotes an upright boiler comprising a vertical cylindrical shell (3 in the lower end of which is placed the fire-box 7. The space between the two is filled with water, as shown in Fig. 1. The fire-tubes 8 extend from the top sheet 9 of the fire-box, as usual. The fire-box extends outwardly from the front of the boiler for a short. distance, as indicated at 10, and at the said end of the boiler it also extends a short distance above the top sheet 9, as indicated at 11. Beneath the top sheet 9 is located an inclined arch 12 of fire brick or other suitable material. The arch extends across the fire box from one side to the other. Its front end extends into the space 11 of the firc box and its rear end extends to the rear wall of the fire box. At the front end of the arch is an upstanding portion 13 spaced from the shell of the boiler and having its top located a short distance above the top sheet 9. The arch serves as a baffle plate to direct the flames upwardly with the portion 11 of the fire box and then over the wall 13 and then back of the arch to the fire tubes, as shown by arrows in Fig. 1. The advantage of this construction is that the fiames and unburned straw are caused to travel around in the recess 11, over the upper edge of the part 13, and the straw is checked by striking a lower end of the boiler, giving it time to burn more completely before reaching the fiues, and
thereby preventing clogging the tines with unburned straw, which a well known dcfect in straw burners. l urthcrmore, the the heats the water in the hollow walls of the fire box, particularly at the top part thereof, where it projects above the end 13 of the ball'le plate, which causes an in'iproved circulation in the boiler, and the lower end of the boiler projects into the fire box, so to speak, whereby the flames strike the outer shell of the boiler, giving an increased heating surface. If the top sheet of the boiler were straight across, the burning straw would draw directly into the fines, choking them at once.
Through the front wall of the fire box 7 passes a straw chute 14lprovided with an upwardly and inwardly swinging door 15. The chute enters the fire box near the front end of the arch 12 and at the discharge end of the chute is mounted an inclined deflector plate 16 to prevent the straw fuel from being carried along with the draft.
In the fire box, below the discharge end of the chute 14, is located a dead-plate 17 to hold the fresh fuel. Below the dead-plate is arranged a traveling or chain grate comprising grate bars 18 carried by endless chains 19 which travel over sprocket wheels 20. The grate may be operated by any suitable mechanism. I have shown a sprocket wheel 21 on the shaft of one of the sprocket wheels 20 which may be connected by a chain to any suitable running part of the engine and geared so as to give the proper speed. Any other suitable driving gear may be employed.
In the front wall of the fire box, below the chute 1a is an opening 22 which leads to an ash-box 23 provided with a door 2% in its bottom. The chain-grate passes through the opening 22 into the box 23. The grate is inclined, its front end being near the top of the ash-box and its rear end being near the rear wall of the fire-box and close to the floor of the latter and beyond the end of the deadplate 17.
The object of the chain grate is to prevent the fire box from filling with ashes, or, in other words, to maintain a clean fire, and also to keep the ashes from beneath the grate and to draw them into the box 23 from which they may be readily dumped upon openmg the door.
In the rear wall of the fire box, near the bottom thereof is a draft opening 25 fitted with a damper 26. In front of this draft opening are diagonal stationary grate bars 27. The rear wall of the fire box, above the arch 12, is also provided with a cleaning door 28.
By the structure herein described a practical and highly efficient straw-burning furnace is had, and the accumulation of ashes, which is a source of much trouble in this type of furnaces, is effectually prevented.
The parts are simple and few and are readily accessible by reason of which the furnace can be easily kept in good working order.
1. The combination with an upright firetube boiler and a fire box thereunder, the tubes of the boiler opening through the top of the fire-box and the front part of the latter projecting forwardly beyond the boiler, of a baffle plate extending forwardly across the fire box from its rear wall and under the entrance for the fire tubes and projecting at its front end above the entrance of the said tubes.
2. The combination with an upright fire tube boiler, of a fire box thereunder having an extension in front of the boiler shell and above the top sheet, a baffle plate extending across the fire box below the top sheet and the tube inlets and projecting forwardly and upwardly from the rear wall of the fire box and into the extension, and a grate below the ba'l'l'le plate.
In testimony whereof I aHiX my signature in presence of two witnesses.
DANIEL L. BROVNFIELD.
lVitnesses L. A. WVEsToN,