US2412193A - Fuel feeding apparatus - Google Patents

Description

1946' I A. o. ANDERSON 2,412,193

FUEL FEEDING APPARATUS Filed Aug. 2a, 1945 4 Sheets-Sheet 1 IN V EN TOR.

A T TORNEYJ Dec. 10, 1946. A. O. ANDERSON FUEL FEEDING APPARATUS Filed Aug. 23, 1945 4 Sheets-Sheet 2 INVENTOR. flc'f/zur Qflndewou 21 amzfxdaaw AT TOPNE YU' Dec. 10, 1946.

A. o. ANDERSON 2,412,193

FUEL FEEDING APPARATUS Filed Aug. 23, 1945 4 Sheets-Sheet 3 IN V EN TOR.

ATTOPNE YS Dec. 10, 1946. Q ANDERSON 2,412,193

FUEL FEEDING APPARATUS Filed Aug. 23, 1945 4 Sheets-Sheet 4 ATTORNEYJ Patented Dec. 10, 1946 UNITED STATES PATENT OFFICE (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 7 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

The present invention relates generally to the art'of fuel feeding. More particularly, it providesfor an improved attachment for a solid fuel feeding apparatus of ,a standard heating furnace which comprises means for speedy and easy access to the interior of the feed mechanism housing.

Specifically, the improved attachment includes a hinged interiorly tapered combination coupling and coal chamber adapted to house the feed mechanism of a conventional automatic stoker. The chamber is provided with releasable locking means-and may be opened for exposing said feed mechanism through 360 by manual manipulation of the locking means.

In the past in connection with the operation of solid fuel stokers, especially with the underfeed type, it occasionally has been found that a relatively-large piece of steel or other hard material has become mixed with coal in the bin or hopper in which it was contained in such a manher that the foreign matter has been fed along with the coal into the feeding tube where it sometimes came in contact with the fuel feeding mechanism and became wedged between the fuel feeding mechanism and the tube housing it, in such a manner as to stop rotation of said fuel feeding mechanism. When this occurs a shear pin normally employed in the fuel feed drive shaft is broken, thereby severing the connection between the prime mover and the drive shaft. In such a contingency, it is usually necessary to shovel all of the coal away from the fuel outlet in the bin, when such a receptacle is used for the fuel, and to employ a lever arm or other tool for manually reversing rotation of the torque screw or other feeding means to disengage the steel or other foreign object. In cases where a hopper is used it is usually necessary to completely unload the hopper in order to gain access to the interior of the housing of the fuel feeding mechanism. After removal of a foreign body a new shear ,pin may be inserted in the driving shaft, the hopper reloaded and the stoker again placed. in operation.

Obviously the above described process is an ineillcient and time-consuming repair job. Accordingly, one-of theobjects of the present invention isthe construction of a device providing convenient and speedy access to the fuel'feed ingmechanism of an automatic stoker for facil- 2 itating repair and/or adjustment necessary to assure smooth and efiicient operation of the fuel feeding mechanism.

Another object of my invention is to furnish a sectioned combination coupling and fuel chamher for the conveyor tube of an automatic stoker which may be opened substantially through 360 by manual release of a simple locking means.

A further object of the present invention is the provision of a modified fuel conveyor tube for an automatic stoker adapted to receive a readily removable flanged coupling and fuel chamber.

, An additional and important object of my invention is the construction of a coupling forthe conveyor tube of an automatic stoker adapted for compression of the fuel into the grooves of the fuel feeding means substantially entirely within the coupling.

A still further object .of my invention is the provision of a combination coupling and fuel chamber adapted for installation into existing stoker assemblies with relatively few alterations to the existing plant.

' Preferred embodiments of my invention whereby I attain the above and other and further objects are illustrated in the accompanying drawings in which like numerals refer to like parts throughout the several views and wherein:

Fig. 1 is a schematic layout showing one form or arrangement of a solid fuel bin or hopper, a fuel feeding tube, a furnace and the attachment constituting the improvement of the present invention;

Fig. 2 is a perspective view illustrating the means of application of the fuel chamber vcoupling to the conveyor tube of a stoker and shows one form of lockingmeans used to retain the coupling member in locked relationship relative to said conveyor tube; v

Fig. 3 is a side elevation, partly in section, showing the interiorly tapered coupling member and the manner in which it is attached to the conveyor tube of a stoker;

Fig. 4 is an end view .of the hinged coupling device in opened position;

Fig. 5 is an end view of the coupling device of Fig. 4 showing the device in closed and locked position;

Fig. 6 is a view of the conveyor andfuel feed tubes of a stoker with the hinged coupling member completely removed;

Fig. 7 is a view similar to Fig. 6 but showing the hinged coupling secured tothe fuel feed and conveyor tubes; and

Fig. 8 illustrates an alternative construction for locking the hinged sections of the coupling chamber.

Referring to Fig. 1, the numeral l designates a bin or hopper for solid fuel. A relatively short cylindrical fuel feeding tube 2 is connected to the bin and has secured thereto the improved attachment designated generally by the reference numeral 3 constituting the present invention as hereinafter described. The numeral 4 indicates a conventional furnace. The fuel bin I is provided with a generally circular fuel outlet to which is connected the fuel feeding tube 2 as by means of an annular flange member 5 adapted to be secured to the fuel bin l by means of any suitable fastening means'such as bolts passed through apertures 8 formed in the annular flange member. The attachment 3 comprises a combination coupling and fuel chamber 1 which is adapted to form a connection between the free end of the fuel tube 2 and a fuel conveyor tube 8 and also to house fuel feeding mechanism such as a torque screw or worm 8 (Fig. 2) The conveyor tube 8 is of smaller diameter than the tube 2, for a reason which will hereinafter become apparent.

The member '1, preferably made of cast iron, is generally similar to the hollow frustum of a cone and is interiorly tapered as at ill (Fig. 3). The inside diameter of the fuel chamber 1 at the end of the taper l0- adiacent the entrance to the conveyor tube 8 preferably is slightly less than th inside diameter of the latter. With this construction any impediment to continued operation of th feeding means which may be contained in the fuel being fed by the worm 9 will be trapped in the chamber 1 without being passed on to the tube 8 where it would be difflcult to retrieve it. The inside surface of the chamber 1 may be either smooth or ribbed. The chamber may consist oftwo or more substantially identical sections (twoin the present instance) indicated by numerals I l and fiend hingedl-y connected as at l3 by means of a-pintie- M. Eachof'these sections is provided with twosemicircular collar elements I! and positioned at opposite ends'of the chamber. These collar elements are g-rooved on their inner peripheries in the manner indicatedat i'i'in Fig. 3', which construction adapts them for cooperation with chamfered annular flanges or ribs i-fland i8 formed respectively at one end ofthe fuel feed tube 2 and th conveyor tube 8 for securing the coupling in position and for preventing axial displacement thereof. As shown most clearlyin Figs. 2, 3-, and '6 the flange 18 is formed on-the' end-of! an adapter member 80- having its other end formed-as asleeve-fitting around the outside of'the open end of tubes and secured thereto by any suitable means such as welding.

Various devices for maintaining the hinged sections it and i 2 of theschamber 1" in locked relation. relative to eachother may be employed. Figs. 1-5 and 7 show one form of the locking device and Fig. 8 shows an alternative form which I have chosen to illustrate and describe herein.

"The device shown in Figs. 1-5 and 7 comprises a bolt 20 pivotally connected at one end as'by means-of a pin '21- to a substantially U shaped deg'zz which 'may be formed integralfwith the body portion of the section H of the coupling chamber 'l'-.- The bolt 20 is threaded at one end and is adapted toreceive a complementary interiorly threaded tubular locking member 23-and a-washer M and to fit into a second substantially U-shaped dog 24 formed integral with the body portion of the other section i2 of the chamber 1. The dogs 22 and 24 may be reinforced in their connections to the collars i5 and (6 respectively as by means of inclined flanges or ribs 25 and 26 as shown in Fig. 2. The two sections. ii and i2 of the coupling chamber 1 are adaptedto be releasably locked by manipulation of a handle 21 positioned adjacent one end of the locking member 23 and extending therethrough, the locking member being adapted for projection against the washer 3i by the cooperation of. its interiorly threaded portion with the threaded part of the bolt 20.

The coupling chamber 1 may be further secured against rotation relative to the ribs I8 and i9 by means of a pair of dowel pins 28 adapted topin the collars l5 and I6 respectively to the annular flanges I8 and ill by means of a slot in each of the latter, as shown at 29 in Fig. 2. The pin 28- is preferably made of soft. steel and. may be inserted at any convenient point toss cure the desired result. This pin is. preferably substantially equal in strength to the shear pin usually employed in stokers to break the connection between the prime mover and the fuel feed driveshaft in emergencies which may arise through malfunctioning of the fuel feeding mechanism. through failure of the screw or worm carrying shaft to rotate due to an obstruction in the fuelto be fed or otherwise, as is well understood in the art. It will be-evident'that by reason of the tapering of the chamber solid fuelfed into the interior thereof will lie-compressed into the spiral grooves of the feed screw 9 substantially entirely within the chamber. Consequently if there is any foreign object mixedwith the fuel it will be engaged, if at all, between the feed screw and its surrounding enclosure at some point within the feeding chamber. Thus should lube-necessary to remove any obstruction affecting smooth continuous operation of? the fuel feeding screw it can be easily and quickly accomplished-by releasing the locking'bolt 2a, disengaging it from the dogs 22 and 24- and removing the hinged chamber I entirely as shown in Fig. 6.-

Fig. 8 shows a. modified form of attachment designated by the numeral 1a and having allthe characteristicsof the attachment I except-that twolocking bolts and four dogs are-employed; Corresponding similar parts aredesignated by corresponding reference characters towhich the exponent ai'has -been added;

As previously mentioned-one of the important features of my invention resides in the ease and simplicity with which itmay beincorporated into known types of fuel feeding assemblies with but slight modifications to the existing plant; For example, a typical installation prior to-modification to incorporate my improved coupling will bear-ranged insuch manner thatthetube- 8 is constructed as a continuous single member having enlarged flange means secured to its end adapted for fastening directly tothe-hopper I-'. It isaccordingly onlynecessary in-such cases toremove the enlarged flange and substitute my double flanged cylindrical member 2 therefor; sever a short section from the tube Elfand secure the adapter flange 30 in place on the-sevcred end of tube 8. "I-he assembly will then be inthe condition illustrated in Fig. 6 in readiuses toreceive my improved coupling device '3 which may then be fitted over the flanges l8 and i8 and securely but i-eleasesbly melted in place by-the-bolt- 20 and shear pins-28. his-there are many known types of stoker assemblies the details may vary slightly according to the different modifications encountered but in each case the alterations necessary will be of a relatively minor character and extent.

Although I have illustrated and described herein only preferred embodiments of my coupling chamber, it is obvious that others of many types and variably positioned, could be used depending upon the length of the fuel feed tube and -of the conveyor tube. Also my invention is adapted among other things for use in overfeed. underfeed and central feed stokers and it is not therefore my intention to be limited to the underfeed type illustrated.

Many alterations and modifications of the present invention will no doubt occur to those skilled in the art and I do not therefore desire to be restricted by the precise disclosure made herein. Accordingly it is my intention to be limited only by the prior art and the appended claims.

I claim:

1. In a stoker for feeding solid fuel from a fuel source to a furnace, a fuel inlet tube, means for connecting one end ofsaid fuel inlet tube to aid fuel source, an annular rib on the other end of said fuel inlet tube, a fuel conveyor tube, one end of which is adapted to be connected to a furnace, an annular rib on the other end of said conveyor tube, said ribbed ends of said inlet and conveyor tubes being coaxially spaced apart, fuel-feeding mechanism housed by said tubes but exposed at the spaced apart ribbed ends of said tubes, an interiorly tapered fuel chamber interposed between the ribbed ends of said tubes and having first and second separable sections, said fuel chamber being adapted to house that portion of said fuel-feeding mechanism between the ribbed ends of said tubes and to compress fuel between the walls of said chamber and said fuel-feeding mechanism substantially entirely within said chamber, means for hingedly connecting said sections whereby they may be opened and closed through 360 about the aforesaid portion of said fuel-feeding mechanism, keeper means on each of said sections, releasable latch means cooperable with said keeper means for releasably locking said sections in closed position, a pair of complementary coilar elements at each end of said fuel chamber sections, means forming a groove on the interior of each of said collar elements, each pair of said collar elements being adapted respectively to encircle the ribbed ends of said tubes with said grooves embracing said ribs for substantially preventing axial displacement of said fuel chamber sections relative to said tubes, and means for confining said fuel chamber against rotation relative to said tubes.

2. In a stoker for feeding solid fuel from a fuel source to a furnace, a fuel inlet tube, means for connecting one end of said fuel inlet tube to said fuel source, an annular rib on the other end of said fuel inlet tube, a fuel conveyor tube, one end of which is adapted to be connected to a furnace, an annular rib on the other end of said conveyor tube, said ribbed ends of said inlet and conveyor tubes being coaxially spaced apart, fuel-feeding mechanism housed by said tubes but exposed at the spaced apart ribbed ends of said tubes, an interiorly tapered fuel chamber interposed between the ribbed ends of said tubes and having first and second separable sections, said fuel chamber being adapted to house that portion of said fuel-feeding mechanism between the ribbed ends of said tubes and to compress fuel between the walls of said chamber and said fuelfeeding mechanism substantially entirely-within said chamber, means for hingedly connecting said sections whereby they may be opened and closed through 360 about the aforesaid portion of said fuel-feeding mechanism, releasable latch means for releasably looking said sections in closed position, a pair of complementary collar elements at each end of said fuel chamber sections, means forming a groove on the interior of each said collar elements, each pair of said collar elements being adapted respectively to encircle the ribbed ends of said tubes with said grooves embracing said ribs for substantially preventing axial displacement of said fuel chamber sections relative to said tubes, and means for confining said fuel chamber against rotation relative to said tubes.

3. In a stoker for feeding solid fuel from a fuel source to a furnace, a fuel inlet tube, means for connecting one end of said fuel inlet tube to said fuel source, an annular rib on the other end of said fuel inlet tube, a fuel conveyor tube, one end of which is adapted to be connected to a furnace, an annular rib on the other end of said conveyor tube, said ribbed ends of said inlet and conveyor tubes being coaxially spaced apart, fuelfeeding mechanism housed by said tubes but expose-d at the spaced apart ribbed ends of said tubes, an interiorly tapered fuel chamber inter-' posed between the ribbed ends of said tubes, said fuel chamber being adapted to house that portion of said fuel-feeding mechanism between the ribbed ends of said tubes and to compress fuel between the walls of said chamber and said fuelfeeding mechanism substantially entirely within said chamber, means providing for interior access to said chamber to expose a portion of said fuelfeeding mechanism between the ribbed ends of said tubes, a pair of collar elements respectively at opposite ends of said fuel chamber, means forming a groove on the interior of each of said collar elements, said collar elements being adapted respectively to encircle the ribbedends' of said tubes with said grooves embracing said ribs for substantially preventing axial displacement of said fuel'chamber sections relative to said tubes, and means for confining said fuel chamber against rotation relative to said tubes.

4. An attachment for a stoker adapted to be releasably secured to a fuel conveyor tube of said stoker, said attachment constituting a housing for a portion of the fuel feeding mechanism of the stoker and comprising a fuel chamber having first and second separable sections, means for substantially preventing axial displacement of said sections relative to said fuel conveyor tube, means for hingedly connecting said sections whereby they may be opened and closed relative to each other for exposing a portion of said fuel feeding mechanism through 360, keeper means on each of said sections and latch means cooperable with said keeper means for releasably locking said sections relative to each other.

5. An appliance for an automatic stoker adapted to feed fuel to a furnace from a fuel source by means of fuel feeding mechsnism housed in a conveyor tube, said appliance constituting a housing for a portion of the fuel feeding mechanism and comprising an interiorly tapered fuel chamber, means for connecting one end of said chamber to said conveyor tube and coaxially therewith, means for connecting the other end of said chamber to a fuel inlet tube, said chamber being adapted to compress fuel between the walls thereof and the fuel conveyor means substantially entirely within said chamber, and means for disconnecting said fuel chamber from the conveyor tube and the fuel inlet tube for exposing 'the aforesaid chamber housed portion of the fuel feeding mechanism through 360'.

6. In combination, in a stoker for feeding solid fuel from a fuel source to a furnace and having fuel feeding mechanism, an interiorly tapered fuel chamber having means for access to the interior thereof and adapted to house a portion of said fuel feeding mechanism, means for connecting said fuel chamber to said fuel source, means for connecting said fuel chamber to said furnace, said tapered chamber being adapted to compress 8 fuel fed therethrough between the walls thereof and the fuel feeding means substantially entire- 1r. within said chamber.

'7. A device for a stoker adapted to be releasably secured at one end to a fuel conveyor tube in said stoker, and at its other end to a fuel inlet tube from a fuel source, said device constituting a housing for a portion of the fuel feed mechanism of said stoker and comprising a tapered fuel chamber having at least two sections adapted to be opened and closed relative to each other, and means including the aforesaid sections for disconnecting said fuel chamber from said conveyor tube and said fuel inlet tube for ex-' posing said fuel feeding mechanism through 360.

ARTHUR O. ANDERSON.

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