US1457521A - Powdered-coal apparatus - Google Patents

Description

June-5, 1923.

A. J. GRINDLE PbWDERED COAL APPARATUS Filed July 29, 1919 '2 Sheets-Sheet 1' Invent: f frz'ndie June 5, 1923 1,457,521 A. J. GRINDLE POWDERED COAL APPARATUS I Filed July 29 1919 2 Sheets-Sheet 2 fl /[115471111 g Patent Junei,

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Application flied ma a, 1919. Serial No. 314,136.

- thereof.

The invention relates to apparatus for the use of powdered coal as fuel an has for its object the provision of improved means for obtaininga uniform regulated feed of the .comininnted fuel'into a uniform and j correspondingly regu-lated volume of air for delivery of the air and fuel to a jet burner at the'furnace. v

In the accompanying drawings; Fig. 1 -is a detail side elevation of the apparatus showing the fuel hoppenblower, th'e air and'fuel regulating devices and adjacent'portions of the conduits leading to the furnaces; Fi 2 is view takencentrally through the fuel feeding mechanism and the air regulator with adjacent portionsof the conduit;

Figs. 3and are detail sectional views taken 'on the lines 3 3 and44 respectively of Fig. 2,,the face of one of two companion fuel plates being shown in Fig. i;

Fig. 5 is a face View of the other 'fuel generally of like construction for the different burners, the drawings and the following description are principally confined to apparatus which has for its function the maintenance andregulation of a powdered fuel supply for a single burner.

As shown, a motor 10 is directly connected to the blower 11, and is belted to a pulley, as 12, carried by the drive shaft, as 13, of a change speed gearing generally designated 15. This change speed gearing may 6 be of any well known type and the mechanism of the. same is not illustrated in detail, In the present construction it is employed for driving the fuel feeding screw 17. It follows that by movement of the controlling handle 16 of the change speed gearing the speed of the fuel feeding screw 17 may be varied while the soeed of the shaft 13 remains constant. 'lhe delivery of fuel to each burner may thus be separately varied or discontinued entirely without changing the speed of the blower 11.

Screw 17 is mounted upon a shaft'19 and extends lengthwise through a casing 18 which preferably takes the'form of a trough having a tubular outlet 18* at one end but with the body portion of the trough constituting one compartment of the'lower end of the powdered fuel hopper 14. Under these circumstances, the tubular outlet 18 extends to and connects with an upright portion 23 of the conduit leading to a singleburner. For uniform delivery of the fuel I prefer to form the screw 17 with a plurality of threads,

v w four being shown, and while the external a detail longitudinal sectional diameter of the screw is preferably the same throughout its length, the depth of the threads is desirably varied, as by reason of the tapering shape of the sleeve 20 upon which the threads are formed, the greatest depth of thread being adjacent the dis- B .5

charge end of the screw.

'A pair of cooperating oppositely facing roughened plates 21, 22, one of them stationarily mounted adjacent the discharge end of the feed-screw 17, the other plate revolving with shaft 19, are provided to break 1 up compacted masses of the powdered fueli discharged by the feed screw 17 and to there. by further promote the delivery of the fuelat a uniform rate; That is to say, the pro-'v vision of a plurality of the threads upon the feed screw 17 insures a substantially uniform discharge of the fuel by the frequent delivery of relatively small quantities or masses and the plates 21, 22,insure that these quantities of fuel will be delivered to the air gradually rather than in the compact masses in which they might otherwise fall from the end of the screw. The plates 21, 22, are accordingly regarded as equalizer plates.

The distance between plates 21 and 22 may be adjusted by loosening the set screw 24, securing plate 22 to the shaft 19'and sliding. the plate lengthwise on the shaft. When the separation of the plates 21; 22511218. once 110 ing 25 secured by means ol set screws, as

26 within the tubular outlet portion 18 of I the casing 18. lpon removal of the bushthe equalizer plate 22.

ing 25 a sleeve (not ll')\\lll of like size with the. bushingbut of greater length may be introduced about the feed tl'(\\' 17 throughout its full length. thereby permitting removal and replacement oi the feed screw without emptying the hopper it. Furthermore. the hearing. as T9, in which the shaft 19 is journaled at its outer end. is carried l) a removable plate 79. of larger size than Removal of plate 79 accordingly provides an opening inv the wall of the conduit portion 2 through which the equalizer plate 22. bushing 25 and feed screw 17 may be withdrawn.

A separate branch 27 of the common blower outlet. as 27. connects with a valve casing 28. which valve casing is in turn connected with the lower end of the upright conduit portion 23. As shown. the valve casing 28 is cylindrical in form with its axis transverse to the axis of the conduit and with cirular elosed'sides. The inlet and outlet openings of the val"\ 'asi'ng 25 are sul'istantially rectangular in shape. as indicated in Figs. 3 and at. A convenient and compact arrangement of parts is provided it the valve. casing 28 is supported immediately below casing 18 adjacent the outlet end of the same. as by means of companion lugs 30. formed on said two parts, and connecting bolts 32.

-Within the valve casing 28 is transversely mounted a valve gate 34 which is, in form, a portion of a cylinder and of a. size to fitclosely within the casing. Each end of the valve gate 3a is preferably formed with an inturned flange 35. These flanges are each provided with a trunnion 36 or 37, and each of these trunnions '1; mntrally journaled in the adjacent circular side wall. of the valve casing 28. As a means for manually adjusting-the valve gate 34, one of the trnnnions. as 37, extends beyond its b aring for the reception of an adjusting crank 38. and this crank carries a handle 39 and a pointer 40, which moves over a graduated scale 41. To prevent accidental derangement ot' the valve gate 3 1 the crank 38 may be provided with a bolt 49, traveling in a slot, as 43 and this bolt is constructed to be tightened in ad- }usted osition by rotating the handle 39. ndioatlng buttons. as 44:, preferably numbored to correspond with the numbering of the different positions of the controlling handle 16 of the change speed gearing 15, are adjustably located upon the edge of the scale 41, in accordance with previously determined positions of the, valve gate to admit the most desirable quantity of air to each i conduit while the corresponding teed screw 17 is operating at each of the-several speeds permitted by the said change speed gearing. The scale 41 is preferably also graduated to indicate the number of square inches of valve opening which correspond with the several positions of the pointer on the scale. After the buttons 44 are once adjusted upon the scale 41 it is only necessary. when feeding fuel at the rate provided by anyone of the speeds of the screw 17. to swing the pointer 40 to the button corresponding to that speed. when the most beneficial volume of air will at once be supplied by means o1 the air blast. As the blower 11 and feed screw 17 are driven by the same motor. as 10. these adjustments will be'independent of the speed of the feed screw 1,? and plates :21. "22. This is desirable both to provide room for the plates 21, 22-. within the conduit and for the placing of the fuel into the blast to the best effect. A part of the air blastthus. sweeps upwardly between plates 21. thereby lifting the fuel in a direction opposite to that in which it would otherwise fall by gravity. and affording an tltlflltlfilltll means tending to promote a uniform delivery of the fuel into the air blast.

Lonnectmg member 46. 1onnng conduit 23 at flange 45, is rectangular at its lower portion and circular in its upper portion. thus changing from the rectangular form oi" con-,

duit to the circular form. which produces better resultsthrough the elbow. as 47. or other necessary turns leading to the furnace. In the arrangement shown. elbow 47 of the conduit terminates with flange 48 for direct connection with another part, as 58. of the conduit, which may be the earbureter described and claimed in my concurrently tiled application for patent in powdered coal apparatus. Case R. Serial No. 314,137.

I claim as my invention:

In a powdered coal apparatus. in combination, a fuel hopper. a. feed screw at the bottom of said hopper, ashatt carrying the screw and extending beyond the same at. its delivery end, a stationary ribbed plate surrounding the feed screw at its said delivery end. a second ribbed plate carried by and re volving with said shaft. and adjustably spaced from said first named plate, a con- .duit enclosing said plates, means for problast.

v AUBREY J. GRINDLE.

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