US1791099A - Fuel-burning device - Google Patents

Description

Feb. 3,1931. HJG. LYKKEN 1,791,099

FUEL BURNING DEVIGE Filed Sept. 11, 1926 Eng G. mew- Patented Feb. 3, 1931 arse srATE-s unan- HENRY G. LYKKEN, F MINNEAPOLIS, MINNESOTA rnnnsnnn'rne nnvrcn Application .filed September 11, 1925. Serial No. 134,732.

The present invention relates to the burning of fuel, such as coal.

Among the objects of the invention is to' provide a novel fuel burning device, such as for locomotive boilers, particularly for the burmngof pulverlzcd or powdered fuel, such as pulverized coal and the like. Attempts at using a powdered fuel in locomotives, having lire tubes ahead of the fire box, have been unsuccessful for several reasons, such as the inadequacy of the combustion space or spaces for the powdered fuel to attain complete or proper combustion, correct draft effects on the firebed in the firebox, and the'design of a 16 locomotive for usual firing being improper for powdered-fuel.

The present invention, therefore comprehends the provision of a series of combustion spaces or chambers, preferably of large 20 capacity, wherein efficient combustion of powdered fuel may be effected. in a specific embodiment this may be attained by providing a large combustion chamber ahead of the firebox so as to act as a secondary combustion chamber and the firebox space may act as a primary combustion chamber. The secondary combustion chamber may also act as a large flue. Preferably, this chamber has corrugated walls for giving added heating surface and for facilitating the differential eX- pansion and contraction thereof. It may also have means for supporting it whereby it may slide when expanding or contracting. Specifically, the support may comprise supporting members located in the water and steam containing space around the corrugated chamber, and be secured to the outer shell, and have ledges or supporting surfaces upon which may rest or be supported, supporting elements rigid with the chamber. Differential rzpansion of the outer shell and this chamber may be compensated by the supporting members and elements relatively sliding.

Another object of the invention is to proride means for maintaining an incandescent l'u-ebed, such as a bed of fuel upon a grate, and

directing one or more streams of powdered fuel, preferably mixed with a supporter of combustion, such as air, toward the lirebed as downwardly C(EWilliltllG same. Means may also be provided, preferably, for controlling and regulating the mixture, both as to the total quantity supplied to the chamber of the firebox; and als as to the relative proportions of the powdered fuel and the air. The

firebedimay act as a means for igniting the projected mixture and also ,to maintain the same ignited. Means are also provided for supplying air to the firebed or for cutting off the air entirely, dependent upon the load to be carried by the locomotive. W hen operating at a high rate or under a heavy load, the heat transfer is preferably practically all effected from combustion of powdered fuel v and air, in tl e primary and secondary chainbers, but when the locomotive is at a low load, coasting or the like, the powdered fuel may be accordingly reduced, or cut off and the heat from the firebed used only, air being admitted in the desired amount for such effect. Should the powdered fuel device cease to operate for any reason, as by reason of damage occasioned thereto, the firebed may be operated in the usual manner for operating the locomotive under reduced power or load. 7 Desired heat effect may also be had by a combined combustion of the powdered fuel and of the fuel on the firebed with the required amount of air for supporting combustion of the latter. I V Another object of the invention is to effect the heat transfer mainly by radiation. Combustion of the powdered mixture is preferably initiated and partly effected in the primary chamberand substantially completed 8 in the secondary chamber, volatiles in the fuel distilling off in the heat ofv the primary chamber with the products of distillation breaking up so that the larger part of the volatiles are burned in the primary chamber.

Nearly all of the carbon will burn to carbon monoxide there. The higher heat in the relatively larger secondary chamber or flue, and

the sufficient supply of air oroxygen supplied will effect a'complete combustion therein, so that the carbon-monoxide is burned to carbon dioxide, and the combustion completed therein. The greater part of the heat produced in these chambers will be absorbed or trans- 10o ferred through the wall of the secondary chamber.

The invention may or may not include as a feature, a waste heat absorber or economizer, preferably located at the discharge end of the secondary chamber. No means for inducing a draft is necessary and hence the back pressure on the engine heretofore found necessary, is wholly eliminated in this invention, thus adding to the efficiency of the plant. The pressure of the fiuidal mixture at the blowers for projecting the powdered fuel through the burner is low but sufficient to effect a flow of the products of combustion through the heat absorber, and for the removal of the gases from the stack.

By utilizing large volume combustion chambers, the passage of the material, gases and flames therein, is without substantial resistance and is much freer than through a multiple of fire tubes heretofore used and requiring high induced draft. Progressive burning in the chambers is efiected with a completion of combustion in the secondary chamber, and hence a maximum transfer of heat.

In this invention the ash pit is entirely closed or sealed air tight with the exception of a control door for admitting air into the ash pit and beneath the grate holding the incandescent fire bed. The control door may be entirely closed or held in adjusted position for regulating the amount of air to be admitted to the fire bed.

The terms incandescent or incandescence used herein are used in the sense of low degrees of incandescence or glowing as well as of higher degrees thereof.

Other objects, advantages, capabilities and features are comprehended by the invention as will later appear and are inherently possessed thereby.

Referring to the drawings,

Fig. 1 is a longitudinal sectional view through a locomotive boiler constructed in accordance with the invention;

Fig. 2 is a fragmentary top plan view of a rear portion thereof showing parts in broken section; and

Fig. 3 is a transverse sectional view of the boiler.

Referring now more in detail to the drawings, the embodiment selected to illustrate the invention is shown as comprising an outer shell 1 having aspace 2 therein for the containing of water and steam. At the rear end of the chamber is located a fire box or primary combustion chamber 3 in the lower part of which is provided a grate 4 located above a closed ash pit 5. The ash pit may have one or more air admitting openings '6 controlled by adjustable closures 7 cooperating with a sector 8 or the like whereby the closure 7 may be held at any desired adjusted open position. Upon the grate 4 may also be located a fire bed 9 of incandescent fuel. This fuel may be supplied to the bed in the usual way thru a firing or stolring opening 10 normally closed by a fire door 11. The ash pit 5 is normally closed and sealed from entry of outside air except through the opening 6 as controlled by the door 7 Leading from the discharge end 12 of the primary chamber 3 is a corrugated secondary chamber 13 extending for a substantial length throughout the locomotive toward the forward end thereof. This chamber 13 is of large capacity and serves both the purpose of a combustion chamber as well as a fine for the passage of the hot gases therethrough.

For the purpose of supporting this second chamber whereby it and shell 1 may contract or expand, or in other words, whereby both may differentially expand and contract, a supporting means is provided comprising supporting members or ledges 1 1 secured to side portions of the outer shell 1 as by way of rivets or the like 15 and 16. The members 1 1 have supporting surface portions 17 which are substantially in horizontal planes and upon whichrest angular elements 18 secured to the sides of the chamber 13 as by rivets or the like 19. it will also be noted that the width of the surfaces 17 is greater than that of the member 18 so that relative movement of the two may be had for a substantial degree. In this way the chamber 13 is supported upon the members 1i so that if the chamber 3 should expand or contract the members 18 will be adapted to have a sliding movement over the surfaces 17, depending upon the direction of expansion or contraction. On the other hand should the chamber 1 be expanding or contracting, the members 1 1 will slide under the members or elements 18 in the same way. This of course, affords. a simple and facile means for taking care of differential contraction and expansion as re gards the chamber 13 and th shell 1.

At the forward end of the hambcr be provided a heat absorbs compr group of vertical water tunes 20 c eating at the upper and lower with the space 2 in the shell 1 a..- which may pass the products of con from the chamber 1'? to the discharge or olet stack 21. If desired pl te mav used to control the flow of along the tubes 20. in waste heat may remain in the from the chamber 13, will be abs rtubes 20 to preheat the water at end of the locomotive.

The locomotive i ay be provided other features, pert .inin the steam take off 23 the engines and a steam don At the rear end of the locomotive pot 3 is made of large capacity, and has co? nected thereto at the upper part thereof, one

candescent state.

or more burners or nozzles, for discharg ing powdered or pulverized fuel and air downwardly into the chamber 3 and toward the fire bed 9. Each nozzle 25 is connected to a discharge duct 26 having a control valve 27 and leading from a blower or fan 28' having an inlet 29; The fan may also have one or more openings 30 controlled by shutter 31 of any desired construction, whereby additional air may be admitted into the fan to be mixed with the powdered fuel or the sam with the air mixed therein supplied to the fan.

In the operation of the device, a fire bed 9 built and maintained upon the grate in in- The ash pit may be entirely closed or partially opened by adjusting the door 7 One or more controlled and regulated streams of pulverized fuel with the air, is then projected from one or more burners 25 downwardly into the space of the primary chamber 3 and-toward the. fire bed 9. The latter will act to ignite and maintain in ignited condition the combustible mixture. The gate 27 may be of utility to control the total amount of the mixture projected. If it be desired to vary the rich-- ness or leanness of the mixture,,the shutter 31 may be closed or open to vary the amount of air that may be introduced through the opening 30 for mixing with the mixture passing through the blower to the burners.

Combustion first takes place in the chamber 3 so that the volatiles in the coal may be distilled off in the heat in this primary comof it to carbon dioxide. As the burning mass passes into the secondary chamber 13 the c mbustion is completed therein. The heat therein is of a higher degree so that the carbon monoxide will burn to carbon dioxide,

' it being assumed that sufficient air was originally admitted with the pulverized material to make a complete combustion in the secondary chamber. The proper amount of air is controlled by the amount mixed with the pulverized fuel and the amount permitted to be or stopped at a station, the pulverized fuel may be reduced or entirely shut off and pressure in the boiler may be maintained only from the fire in the fire bed 9. More air may be admitted through the opening 6 to make this fire bed burn to the desired amount to of igniting and maintaining in ignition the pulverized combustible mixture. The bed on the grate may be maintained at such a thickness as to protect the grate from the heat in the furnace. ll hen little or no air is admitted through the grate, the material on the grate will remain incandescent, but will burn slowly and requiring very little replenishment. the pulverized coal feed may then'be shut off or reduced to the desired point.

After completion of combustion in chamber 13, the remaining hot gases of combustion may pass through the absorber to give up waste heat to the water and steam at the for- Ward end of the locomotive, after which the gases may pass freely upwardly through the stack 21. No induced draft is necessary in this construction, thus eliminating the disadvantage of the back pressure heretofore necessary in locomotives to produce drafts. The mixture of pulverized fuel and air is supplied to the fire boX or primary combustion chamber under a low pressure sufiicient to causea flow of the gases, while they are burning through the chambers, and finally through the absorber and out through the stack. The rate of flow of these gases may be controlled by varying the speed of the blowers. l/Vhile the gases are passing through the chambers, the larger part of the heat absorbed thereby or transmitted theretois by radiation, a small portion only being absorbed or transmitted by connectionthrough the fire box and flue shell or secondary chamber.

While I have herein described and upon the drawings shown an embodiment of the invention, it is to be understood that the same is not limited thereto but .may comprehend other constructions, arrangements, details, features and other steps of the process, without departing from the spirit thereof.

Having thus disclosed the invention, I claim 1. A locomotive fuel burning device comprising a combustion chamber at one end and.

a stack at the other end, said combustion chamber having a fuel introducing opening in the rear wall thereof, means for normally maintaining a fuel bed in the bottom of said chamber, an elongated tubular extension of approximately uniform diameter leading from the front end of said combustion chain her, and above the normal level of thefuel Then the load drops off the boiler,

bed approximately to said stack, and means for forcibly projecting a mixture of powdered fuel and air into said combustion chamber above said fuel bed so that said mixture will be initially ignited by the fuel bed and its combustion will be completed within said tubular extension.

'2. A locomotive fuel burning device com prising a combustion chamber at one end and a stack at the other end, said combustion chamber having a fuel introducing opening, means for normally maintaining a fuel bed in the bottom of said chamber, an elongated tubular extension of approximately uniform diameter leading from the front end of said combustion chamber to said stack from a position above the normal plane of said fuel bed, said combustion chamber and said extension having walls provided with heat transferring surfaces, means for controlling the air supplied to said fuel bed, means for forcibly projecting a mixture of powdered fuel and air into said primary combustion chamber above said fuel bed so that the mixt-ure will be initially ignited by said fuel bed and its combustion will be completed within said tubular extension, and means for varying the proportions of air and powdered fuel.

3. A locomotive fuel burning device comprising a combustion chamber at one end and a stack at the other end, said combustion chamber having a fuel introducing opening, means for normally maintaining a fuel bed in the bottom of said chamber, an elongated tubular extension of approximately uniform diameter leading from the front end of said combustion chamber to said stack from a position above the normal plane of said fuel bed, said combustion chamber and said extension having walls provided with heat transferring surfaces,'means for controlling the air supplied to said fuel bed, downwardly projected feed pipes connected with the top of said combustion chamber and communicating with the interior of said chamber, and means for forcing a mixture of powdered fuel and air through said feed pipes downwardly into the combustion chamber over said fuel bed so that said mixture will be initially ignited by said fuel bed and its combustion will be completed within said tubular extension.

4. A locomotive fuel burning device comprising a combustion chamber at one end and a stack at the other end, said combustion chamber having a fuel introducing opening, means for normally maintaining a fuel bed in the bottom of said chamber, an elongated tubular extension of approximately uniform diameter leading from the front end of said combustion chamber and above the normal level of the fuel bed approximately to said stack, the wall of said extension being corrugated, means supporting said extension at positions intermediate between its ends, said extension and said supporting means having complemental surfaces upon which the extension is free to expand and contract in any direction, and means for forcibly projecting a mixture of powdered fuel and air into the combustion chamber above said fuel bed so that said mixture will be initially ignited by the fuel bed and its combustion will be completed within said tubular extension.

5. A locomotive fuel burning devicecomprising a combustion chamber at one end and a stack at the other end, said combustion chamber having a fuel introducin opening in the rear wall thereof, means for normally maintaining a fuel bed in the bottom of said chamber, an elongated tubular extension of approximately uniform diameter leading from the front end of said combustion chamber and above the normal level of the fuel bed approximately to said stack, means for forcibly projecting a mixture of powdered fuel and air into said combustion chamber above said fuel bed so that said mixture will be initiallyignited by the fuel bed and its combustion will be completed within said tubular extension, means providing supporting surfaces, and support members carried by said tubular extension and resting freel upon said supporting surfaces as to move in any direction in accordance with the movements due to expansion and contraction of said tubular member.

in witness whereof, I hereunto subscribe my name to this specification.

HENRY G. LYKKEN.

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