US 2441736 A
Description (OCR text may contain errors)
May 18, 1948. E. CQWEBB 2,441,736
y DRIE'R F'OR PNEUMATIC FEED COAL STOKERS Original Filed May 18, 1943 2 Sheets-Sheet l May 18, 1948. E. c. WEBB DRIER FOR PNEUMATIC FEED COAH STOKERS Original Filed May 18, 1943 2 Sheets-Sheet 2 T2, /N VE/v TOR. fR/VEST C. WE'.
/7 77E/WYE Y Patented May 18, 1948 y Oreg.
Damn Fort Egg/Morro man com.
'Ernest C.Welib,-Cleveland, ,01110, assigner to Iron Fireman Manufacturing'-0ompany, Portland,
substituted for abandonedapplicatfon Serial No. 487,505, MayflS,v 1943. This application October 7, 1946, Serial No. 707,549
This patent is a substitute for applicants abandoned application, filed May 18, 1943, Serial No. 487,505.
This invention relates generally to the burning of coal, and particularly to a coal drier.
The main objvect'of vthis invention is to prepare vcoal for burning with a spreader stoker by drying it sufficiently to prevent accumulation, packing or caking of material in the bends and pipes of the coal feeding mechanism, regardless of the moisture content or percentage of dirt and clay contained Within the coal as it enters. the stoker.
The second obiect is to construct a drier for spreader stokers wherein the progress of the coal from the point of storage to the point-.of
sorted inl a coal delivery line oi a spreader Stokerl` in which conveying and combustion ai-rrcannot find their way tothe drier, and inA which.l the drying air is made to. travel a tortuous path through the drying compartment in order to increase the lengthI of the drying time.
The fourth object isto construct a drier" of the class described inwhic-h. the amount of fuel carried off by the drying air will be reduced to a minimum, and in which the moisture extracted. from the fuelY is delivered to the combustion compartment of the furnace. Y
I' accomplish these'and other objects in the manner set forth in the following specification, as illustrated in the accompanying drawings, in which:
Fig, 1 is a fragmentary side elevation of the apparatus showing a portion of the front of a furnace in section.
Fig. 2 is an enlarged longitudinal section through the coal feeding Worm and drier unit. taken along the line 2-2 in Fig. 3.
Fig. 3 is a horizontal section taken along the line 3--3 in Fig. 2.
Fig. 4 is a broken vertical section taken along the line 4-4 1n Fig. 2.
Similar numerals refer to similar parts throughout thelseveral views.
Referring in detail to the drawing, there is shown a. furnace I whose front II has an open- 2 ing t2 communicating with theA co vber I3. i
' lProjecting through the door Il is a nozzle I4 whose tip I5 is hinged to the nozzle I4 by means of the pin I6; and the angularity of the tip I5 is controlled by means of a threaded hand wheel I1 on lthe belt I8 which passes through the bracket lI9 on the nozzle I4 and is connected to the; `tip t5 by means of the' pin 20.
Powdered `and crushed coal 2t is delivered to the nozzle I4 by means of the pneumatic conveyer pipe 22 which, for the pur-pose off providing ...rustica chamoverhead clearancev in front of the furnace, is
bentupwardly as shown in Fig. 1 and. it isy for the v purpose ofpreventing the building? .up of. materials at the bends 2'3, 24. and 25 of the pipe 22 that my drier unit has been devised..
At the bottom end 2'6 oi the-pipe 22 is connected the upright tubular riser 2.-1 whose lower end 28 rests upon the floor 28, and whose opening 3U Yis connected with the discharge pipe 3| of the conveying air fan 32..
Communicating the Z1 is a coal tube 3'3'whichconnects by means of its flanged end 34 with the end 35 of the. drier unit-.whose end 36 is connected by meansof the coal`.tube 31 with the hopper' orv coal bin- 38S.
` erably the same diameter as: the flight40. The
rflight 40`B extendsto the riser Z1.
Although the flight 40 occupies; the larger portion of the tube 31, the flight 4II-A is spaced from the` rounded bottom 4I of the drier unit whose side walls 42 are tangential to the bottom 4I, and whose vertical portion 43 form a rectangular box over which is placed a cover 44 provided with the inlet opening 45 through which air canbe drawn through the pipe 46 which is connected with a source of heat, preferably the combustion space I3 of the furnace itself.
The cover 44 is also provided with an outlet opening 41 which is connected by the pipe 48 to the inlet 49 of the conveying air fan 32. Cleanout openings 50 are provided in one of the walls 43 and are normally closed by the covers 5I.
Below the cover 44 is placed the diagonal, vertical baille plate 52' which is held in place by the rivets 53. Attached to the baiiie 52 is a sloping baiile 52-A whose downward vertical side 52-B is parallel with the longer sides 43 of the drying unit.
The section of the conveying iiight Vfill-,A between the ends 34 and 35 is provided with the paddles 54 which are set at a greater pitch with relation to the axis of the shaft 39 than are the flights of the conveyor 48--A themselves.
purpose of the paddles 54 is to stir or shovei'th'e coal 21|, expo-sing all of the material to the drying action of the air coming in from the pipe 46.-
l, the worm of said conveyor, the portion of the worm having the enlarged clearance having paddles secured thereto operating in said clearance space, the bottom of said clearance space diverg- If clay, or other material is present which would A cake in the presence of heat, it is broken up whi-le soft and friable, and not permitted to bake in enlarged form either before or after it enters l .the pipe 22.
The flight 40-B terminates at the riser 211v andY the shaft 39 has secured on the end which projects into the riser 21, a blade or vane 56, the purpose of which is to loosen or separate the coal 2l as it enters the air stream from the fan 3,2.
On the shaft 39 is also secured a smaller but wider plugging or sealing ight 51, the purpose of which is to cause the tube 33 to ll with fuel and prevent air from the fan 32 blowing through the drying unit or into the hopper 38.
A crushing iiight 58 is placed on that portion of the shaft 39 which is within the coal tube 31, its purpose being mainly to prevent larger pieces of coal 59 from entering the drier unit or the coaltube 33. The flight 58 also serves to keep the tube 31 full of coal and discourage any tendency of air to flow through the tube 31 in either direction, although the natural tendency is for air to flow from the hopper 38 to the drying unit under the influence of the fan 32.
The operation of the device is as follows:
Assuming that the shaft 39 is being rotated in a manner to move coal from the hopper 38 to the furnace l0, and that heated air is circulating through the drier unit, it can be seen that as the coal passes from the tube 31 through the end 36 into the drier unit, some of the coal falls outside of thereach of the flight 4l-A, but into the path of the paddles 54, causing the lcoal to be carried around in a 'circumferential direction while the speed of its longitudinal direction of travel is decreased owing to the greater cross sectional area of the drier unit bottom 4 l.
As the coal enters the tube 33, it tends to iill this tube up and to be discharged into the air stream of the conveying air fan 32. By this time, the coal and dirt and clay'have been robbed of so much of their moisture that they will not build up or collect at the bends 23, 24 and 25, but will pass on out of the tip I5 into the combustion chamber I3, as it is desired that they should in order to satisfactorily stoke the furnace.
ing outwardly to form a trough, said trough having vertical sides and ends above the sloping portion thereof, and having a rectangular horizontal top, said top having air inlet and outlet openings at opposite ends thereof, a diagonal vertical baille plate extending across said box between said 'inlet and outlet openings, a downwardly sloping bale under the inlet opening having a downturned lower edge near the vertical longitudinal plane passingA through said conveyor, means for circulating air through said box, the portion of the worm housing on each end of said trough having sealing iiights lformed thereon adapted to cause the coal tube to fill at the inlet and outlet ends of the trough.
ERNEST C. WEBB.
REFERENCES CITED The following references are of record in the le of this patent:
, UNITED STATES PATENTS Number Wacker June 11, 1901 Hassan June 30, 1907 Kreisinger et al. Nov. 30, 1926 Bergman May 10, 1927 Newhouse May 10, 1927 vKennedy June 16, 1931 Haynes Oct. 20, 1931 Buck Sept. 5, 1933 Hagler et al Feb. 5, 1935 Depew Nov. 26, 1935 Rarey Dec. 15, 1942 Lower May 25, 1943 Davis June 8, 1943 FOREIGN PATENTS Y Great Britain Aug. 7, 1924