US2170277A - Stoker and furnace therefor - Google Patents

Description

g- 9 9- M. C; RICHARDSON 2,170,277

STOKER "AND FURNACE THEREFOR Filed Sept. 21, 1936 6 Sheets-Sheet 1 Ari-U N;

Aug. 22, 1939. M. c. RICHARDSON STOKER AND FURNACE THEREFOR 6 Shets-Sheet a Filed Sept. 21, 1936 v/NA/ENTUR M.c.- R\CH/-\RDSON E Aug. 22, 1939.

Filed Sept. 21, 1936 6 Sheets-Sheet -4 ::I 39 95 109 EI:: x ma A M 40 /3 37 3 112 g 5 7o 1 4 42 I u 4i 0/ 71 102 v 30 {as nvz/swraa M .CRICHAQDSON 9 M. c; RICHARDSON 2,170,277

STOKER AND FURNACE THEREFOR Filed Sept. 21, 1936 6 Sheets-Sheet 5 I M E Y lNLf/VTUR MLRICHARDSOH B V W 22, 3 M. c. RICHARDSON 2,170,277

STOKER AND FURNACE THEREFOR Filed Sept. 21, 1936 6 Sheets-Sheet 6 Patented Aug. 22, 1939 UNITED STATES PATENT' OFFICE I STOKER AND FURNACE THEREFOR Max 0. Richardson, Portland, Oreg., assignor to Iron Fireman Manufacturing Company, Port- 7 land, Oreg.

Application September 21, 1936, Serial No. 101,800

6 Claims. (01. 110-45) This invention relates generally to heating sysparts of relatively small dimensions may be emtems and particularly to a combined form of ployed. stoker and boiler. The twelfth object is to provide a coal feeding The main object of this invention is to provide worm adapted to extend through a stoker retort a complete heating system in which alarge part in which the helix of the worm opposes itself 5 of the stoking mechanism is incorporated in the under the retort and in which the connection boiler itself. between the opposing worm parts serves as an The second object is to provide a combined agitator. boiler and stoker having a straight line arrange- The thirteenth object is to provide an improved 1o ment for the coal conveyor between the coal storform of horizontal, tank type of hopper. age section and the coal burning section and a The fourteenth object is to develop a heating continuous conveyor from the coal burning secsystem in which there is a straight line progress tion to the ash discharge point. of coal from the bin'to the combustion section,

The third object is to construct a heating sysand upward progress of' coal into the combustion tom of the type described so the fly ash which section, then a straight forward progress of coal 15 may pass over into the passages of the boiler will during combustion, and a dropping of the refuse fall into locations above and adjacent to the ash into the ash worm' on the same axis 'as the coal worm in a manner such that it may be readily worm, and the collection of fly ash from the boiler dumped into the ash worm without other manual and the depositing of same into the ash -worm. 2o handling. I accomplish these and other objects in the The fourth object is to provide an improved manner set forth in the specification following form of burning grates adapted to be used in as illustrated in the accompanying drawings, in conjunction with the stoker. .which:

The fifth object is to use an exhaust fan ar- Fig. 1 is a perspective view showing the boiler rangement for drawing off. the' products of comand furnace portion in vertical section in which 25 bustion and to use a simple form of damper which the firepot isshown in elevation.

will permit the furnace to be automatically freed Fig. 2 is a section taken along the line 2-2 in of explosive gases during the shutdown period Fig. 8. 1 and which will automatically cause the combus- Fig. 3 is a section taken along the line3--3 in tion gases to travel the proper heating path dur Fig. 2. 30 ing the operation of the stoker. Fig. 4 is a section taken along the line 4+4 in The sixth object is to arrange the combined Fi 3.

boiler and stoker so an exhaust fan will draw oif Fig. 5 is a section taken along the line 5-5 in the burned gases and that the fan may be mounted adjacent to a gear case and that both the fan Fi 6 is a a m y rear l vat n f th '35 and the worm driving gears may be driven from coal tank or hop Y a single motor. Fig. '7 is a vertical section taken along the line The seventh object is to use an improved form in of hollow or careless worm, Fig. 8 is an enlarged vertical section taken The eighth object is to construct thesystem 1ng itudi1}a]'1y tmfough the P 40 so it may be used either in connection with a 9 1S a horizontal section taken alongfthe coal bin or a hopper. i I 1 The ninth object 1 1, so construct the System Fig. 10 IS a broken vertical section taken along the line l0-l0 in Fig. 8.

that It can be used to an equal advantage with Fig. 11 is a vertical section taken along the line 45 warm air furnaces as well as in connection with in Fig 8 fg and F TP Fig. 12 isa fragmentary rear elevation of the he tenth obJect is to provide an improved system showing the fan i transmission cas- P system 9 the type descnbed In column ing, the ashelevating conveyor, and the ash can non 71th speclal'fonfl of ash removerbroken away in section to disclose the interior 50 The eleventh ob ect is to construct'a stoker of thereof. e yp described wi w to keeping the Fig. 13 is an enlarged verticalsection-through i t thereof a a Inlnimllm and c mplishing the drive mechanism of the coal and ash worm. this saving by starting from the basis of a small Fig. 14 is a horizontal section showing the emdlameter, hollow worm in conjunction with which ployment of an exhaust fan. I55

' extends the double top 23. The front 28 is pro.-

vided with a fire door opening 24 in front of which is placed a fire door 25. The back 2I is provided with a smoke outlet opening 25A which communicates by means of a smoke duct 26 with a stack not shown. Within the smoke duct 26 is placed a. hanging damper 21 which is adapted to close when the furnace is operating and open under a negative pressure produced by the stack when the stoker is not being operated for the purpose of permitting the removal of gases from within the furnace. The smoke duct 26 communicates with a suction fan 28 whose intake 29 extends through the back wall 2I and whose discharge 38 communicates by means of the duct 3I with the smoke duct 26.

Within the boiler is placed the transverse wall or water leg 32 through whose upper portion is formed the opening 33 which in this instance registers with the opening 25 of the back 2I. The walls 28, 2|, and 22 and the wall 32 rest upon the rectangular base composed of the front 34, the back 35,'and sides 36. v Between the sides 36 and directly underneath the wall 32 is placed a wall 31. Between the wall 31 and the back 35 is formed a curved trough 38 in which is free to rotate the fluted ash gate 39 which is rotatably mounted on the shaft 48 which journals in the sides 36. The trough 38 is provided with an opening 4| along its lower side through which the blades 42 project. The front side 43 of'the wall is mounted on one end 48 of a tank or hopper 58. Extending along the bottom of the tank 58 to the front side of the retort 44 is a worm A portion ofthe worm II which is within the tank 68 is providedwith a core 52 on the front end of which is secured a crank 53 whose hub 54 journals in the bearing 65 which forms a part of the tank 58.

Along the longitudinal axis of the tank 58 are placed the short shafts 66 and 51 from the inner ends of which are suspended the forked arms 68 on the lower ends of which are disposed the agitator shoes 59. A rocking motion is imparted to the shaft 56 by means of the slotted arm 68 which is attached to one of the shafts 66. The

in the bottom of the tank 58. The tank 58 issupported by means of the standards 63.

The end 64 of the retort is cylindrical and coaxial with the coal tube 41. The end 64 constitutes an ash removing duct and contains a worm flight 65 which is threaded oppositely to the worm 5I. The members 5| and 65 are joined by an agitator bar 66 which is inclined with relation t0 the axes of the members SI and 65. The hollow worm flight 65 is provided with a spliced coupling 61, and its end 68 is secured to the cam shaft 69 which forms the core for the end of the ash removing worm III. The ash removing worm I8 is disposed within the ash removing tube II which extends into the end I2 on the wall I3 which connects the sides I4. The sides 14 and the wall 13 extend from the floor plate I5 to the outwardly flanged edges I6. Brackets TI project from the sides I4 and support the transverse bar I8. A central support 19 projects from the wall I3 above the connection I2. The side 88 of the retort 44 is sloping and its upper edge lies between the side walls I4.

Between the bar I8 and the edge 8| of the side 88 is disposed the upper sliding grate 82. Between the bar I8 and the support 19 is the lower sliding grate 83. are perforated and integral with the side members 84.

Projecting downwardly from the lower grate 83 are the lugs 85. Hinged to the lugs 85 are the upright arms 86, which are joined by the slotted transverse bar 81.. On the shaft 89 is disposed a cam 88, which engages the slot 89 in the bar '81. The lower ends of the arm 86 are provided with slots 98 which receive 'the pins 9| which project outwardly from the adjacent faces of the lugs 92, which are integral with the wall I3.

The portion of the device just described constitutes the shaking grate by means of which ashes are carried away from the retort to the ash worm I8. It can be seen that a rotary motion imparted to the worms 5| and I8 will cause the cam 88 to move the arms 86 and reciprocate the grates 82 and 83, permitting the burning coal to spread over a relatively large grate surface, upon which it may be burned before passing over the edge 93 of the lowermost grate 83.

It will be noted that the upper side of the ash duct II is cut away from the connection I2 to the back 35 in order to permit the ashes which The grates 82 and 83' are discharged from the grate 83 to find their way into the ash duct 'II.

The fan 28 is operated by a motor 94 which rests upon a shelf 95 formed at the upper end of the upright standard 96 through which the ash duct 'II projects. The ash duct 'II communicates with an ash conveyor housing 91 which is preferably inclined and discharges downwardly into the ash can 98 through a convenient connection 98.

The ash removing worm III has secured to the driven end thereof a shaft I88 on which is placed a sprocket wheel I8I, which carries the chain I82 whose flights I83 travel around the interior of the housing 81 and serve to elevate the ashes from the bottom of the housing 91 and discharge them through the connection 99.

The shaft I88 is provided with a short section of worm flight I84 which is reversed with rela-' tion to the worm 18 in order to prevent ashes from passing axially beyond the conveyor housing 91. The shaft I88 is joined by the universal joint I85 to the shaft I86 of the worm wheel I81,

which is driven by the worm I08 on the shaft I09. The shaft I69 is driven through the helical gears III! and III, the latter of which is secured on the shaft II2, on the outer end of which is secured a pulley II3 whose belt II4 passes around the pulley I I5 of the motor 94. The shaft I66 is provided with a thrust bearing II6 which permits the entire worm sections to be operated in tension, Obviously, the details of construction may be modified greatly without departing from the spirit of this invention.

It will be noted that the blades 42 engage the flights of the worm III, the purpose being to cause the rotation of the worm III to produce a rotation of the ash gate 39.

In this form of the system, it is contemplated to rely upon a mechanically created negative pressure being formed within the combustion chamber 1. v

Air is admitted to the combustion chamber I I1 through an air duct H8, which connects the plenum chamber II 9 formed around the retort 44 and the atmosphere under the control of the damper I20. Air is drawn through the air duct I I8 and delivered to the burning fuel through the openings I2I, I22, and I23 and between the grates 82 and 83 and their adjacent members BI, I8, and 19. The gaseous products of combustion are drawn through the opening 33 and thence carried downwardly through the passageway I24 through the fan inlet 29 into the fan 28 from whence they are discharged through the duct 3| into the smoke duct 26. Obviously, such an action produces a higher pressure Within the duct 26 than exists within the combustion chamber I I1, thereby causing the damper 21 to close.

It will be observed that during the downward travel'of the burned gases through the passageway I24, the solids will be inclined to pass the fan opening 29 and be deposited between the blades 42 of the ash gate 39 and thence be discharged into the ash removing worm l0. Ashes may enter the ash worm I directly from the lower grate 83 while fly ash may enter the worm III by passing around the ash gate 39.

When the motor 94 is not operating, that is, when the fan 28and the worms and III are not being operated, a reverse condition exists, and there is a negative pressure within the smoke duct 26 which causes the damper 21 to open, and gases which may have formed within the combustion chamber III are allowed to pass through the openings 33 and 25 and to escape through the smoke pipe 26 to the atmosphere.

In Fig. 11 is shown the preferred type of coupling for the sections of the worm flight 65. It will be noted that this construction facilitates the joining of the worm parts and permits the separation of the entire worm assembly into lengths convenient for handling.

In the form of the device shown in Figs. 15 to 1'7 inclusive, the construction is the same as in the first described form of the device except in the following particulars. An additional bafiie I25 is interposed between the back 2IA and the transverse baflie 32A, the baffle I25 being directly above the ash gate 39. Instead of employing an exhaust fan in this form of the device, I use a pressure fan I26 which delivers air through the air duct I21 to the plenum chamber II9. It is also desirable in this form of the construction to employ an air regulating damper I28 within the duct I21. When a pressure fan is employed, it is desirable to provide an auxiliary air line I 29, which establishes communication between the fan I26 and the coal tube 41.

In the last described form of the device, the automatic damper I30 may be placed at the top of the baflle I25 instead of in the smoke pipe I3I. The remaining parts are substantially the same as in the first described form of the device.

I claim:

1. In a device of the class described, the combination of a furnace having a bridge wall across one end thereof adapted to form a combustion chamber on one side of said bridge wall and a down draft passage on the other side of said bridge wall, said wall extending upwardly and terminating near the upper part of the furnace, an ash gate forming a closure for the bottom end of said down draft passage, said gate consisting of a revolvable fluted member, a retort at the end of said combustion chamber opposite said bridge wall, stepped shaker grates between said retort and bridge wall, a duct extending through said furnace and retort and below said grates and ash gate, said duct being cut away on its top side to admit ashes thereto, a revolvable conveying element within said duct consisting of a coal conveying screw flight extending from one end of said duct to the near side of said retort, an ash removing flight extending from under said grates to an ash outlet, a reversed flight secured between said coal and ash flights, the junction of said coal and reverse flights being at the bottomof the retort and consisting of a diagonal bar connecting the adjacent ends of the reversely wound flights, a lever hinged at one end to a support and at the other end to the shaker grates and a cam on the axis of said conveyor for actuating said lever in a manner to reciprocate said grates as the conveyor is turned.

2. The combination of a retort having a coal conveyor worm associated therewith with means for feeding fuel upwardly into said retort, grates for carrying the incombustibles away from the end of said retort and an ash conveying worm forming a continuation of the coal conveyor for carrying ashes away from the end of said grates.

3. In a furnace the combination of a combustion chamber having a vertical bridge wall disposed transversely across one end thereof to form a down draft passage between said bridge wall and one adjacent end of the combustion chamber, said combustion chamber being provided with ash'outlets in front of and behind said bridge wall, a closure for the ash outlet of said down draft passage, a retort in the bottom of said combustion chamber including moving grates for discharging ashes through the outlet in front of said bridge wall, a worm conveyor extending through said retort and having one end projecting into a coal container to draw coal therefrom and having the other end extending past said ash outlets to carry ashes therefrom, a can for drawing gaseous products of combustion from said down draft passage and a damper for permitting the gaseous products of combustion to be drawn off over said bridge wall by natural draft when said fan is not being operated.

4. The combination of a retort, a conveying worm extending there'through, one end of said Worm constituting a coal conveyor for drawing coal into said retort and the other end of said worm constituting an ash conveyor for removing ashes from said retort, a shaker grate along one end of said retort over which ashes can pass into said ash conveying worm, a cam mounted on said ash conveying worm and a lever actuated by said cam and connected to said grates whereby the rotation of said ash conveying worm will produce a reciprocating motion at said grates.

5. The combination with a combustion chamber of a retort, a conveying worm extending therethrough, one end of said worm constituting a coal conveyor for drawing coal into said retort and the other end of said wormconstituting an ash conveyor for removing ashes from said retort, a

shaker grate along one end of said retort over which ashes can pass into said ash conveying worm, a cam mounted on said ash conveying worm, a lever actuated by said cam and connected to said grate whereby the rotation of said ash worm will produce a reciprocating motion at said grates, and a transverse bridge wall extendashes can pass from behind said bridge wall into said ash worm. r

6. The combination of a retort, a worm extending therethrough, one end of said worm being adapted to draw coal from a storage point to said 1 retort and the other end or said worm constituting an ash conveyor for removing ashes from said retort, a shaker grate at one end of said retort over said ash removing worm and means for actuating said shaker grate from said ash 15 worm.

MAX C, RICHARDSON.

Images