DESCRIPTION

This invention relates to an apparatus for and a method of distributing particulate material. In one application of the invention the material is formed into a curtain that flows into a spray mixing vessel. 5. In another the material may be divided into a number of separate streams.

According to the invention, there is also provided an apparatus for distributing particulate material characterized in that, the apparatus includes a feeder C23 having a charging inlet (43 and a discharge outlet duct (123,

10. the.discharge outlet duct (123 having converging- alls, a deflector- (263 to deflect particulate material received ^■ from the discharge outlet duct (12), the deflector (26) including a first spreader (283 coaxially aligned with the discharge outlet duct (123 and having walls which diverge

15. away from the discharge outlet duct (123 a second spreader (30 contiguous with the diverging walls of the first spreader(283 and having diverging walls.of an angular inclination to the direction of flow of the particulate material greater than that of the first .spreader (283 so

20. that, in use, the discharge of particulate material from the lower end ^" of the second spreader is uniform.

According to the present invention, there is also provided an apparatus for distributing particulate material characterized in that, the apparatus includes a feeder (23 25. having a charging inlet (43 and a discharge outlet duct (123,

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the discharge outlet duct (12) having converging walls, a deflector (26) to deflect particulate material received from the discharge outlet duct (12), the deflector (26) including a first spreader (28) coaxially aligned with

5. the discharge outlet duct (12) and having walls which diverge away from the discharge outlet duct (12) a second spreader (30) contiguous with the diverging walls of the first spreader (28) and having diverging walls of an angular inclination to the direction of flow of the particulate

10. material greater than that of the first spreader (28), the discharge outlet duct (12) and the first and second spreaders (28, 30) co-operating to produce a hollow curtain of uniformly distributed particulate material.

According to the invention there is also provided

15. a method of distributing particulate material characterized in that the method includes the steps of charging a feeder (2) with particulate material, discharging the particulate material from the feeder (2) through the discharge outlet duct (12) to produce a substantially uniformly distributed

20. flow of particulate material on a deflector .(263 to produce a hollow curtain of uniformly distributed particulate material.

Embodiments of the invention will now be described ^• by way of example, and with reference to the accompanying

25. single figure of the drawings in which an apparatus for distributing particulate material includes a cylindrical feeder 2 having an open top 4 forming a charging inlet, the periphery of which is surrounded by an external flange 6. Spaced apart from the charging inlet 4 and axially aligned

30. therewith is a circular aperture 8 surrounded by an external peripheral flange 10, the aperture 8 communicating with an axially aligned discharge outlet duct 12 at a lower end

portion of the feeder 2. The discharge outlet duct 12. is frusto-conical in shape having at an upper end portion thereof an external peripheral flange 14 which is attached to the external 5. peripheral flange 10 of the circular aperture. ^• Inner walls of the discharge outlet duct 12 converge and extend towards a lower circular outlet 16 from whose periphery extends a depending cylindrical rim 18.

10. Interposed between the charging inlet 4 and the discharge outlet duct 12 are a plurality of support members 20 each having spaced apart struts which radiate out from a central boss. Each boss is drilled to provide ^' a bore which is aligned

15. with a central axis of the feeder 2. The free ends of the struts are attached to the inner walls of the feeder 2.

A shaft 22 extends through the bores of each of the central bosses of the support members 20

20. such that the shaft 22 is axially aligned with the central axis of the feeder 2. The length of the shaft 22 is such that a lower end portion of the shaft projects beyond the lower circular outlet 16 of the discharge outlet duct 12 and

25. such that an upper threaded end portion thereof

extends beyond a support member 20 adjacent the charging inlet 4. The support member 20 adjacent the charging inlet 4 has a threaded bore and the threaded portion of-the shaft 22 is mated

5. with the threaded bore in the support member and secured by a lock nut 24. The length of the shaft 22 projecting beyond the lower circular outlet 16 may be altered by securing the upper end portion of the shaft 22, releasing the lock

10. nut 24, adjusting the length of the shaft 22 projecting beyond the lower circular outlet 16, and then re-securing the lock nut 24.

^• Attached to the lower end portion of the shaft 22 is a deflector 26 having outer surfaces

15. which diverge away from the discharge outlet duct 12. The deflector 26 includes a conical spreader, co-axially aligned with the discharge outlet duct 12, having an upper portion 28 projecting into the discharge outlet duct 12 so

20. that an annular space exists between the outer surface of the spreader and the inner wall of the discharge outlet duct 12, and a lower portion 30 remote from the feeder 2.. The lower portion 30 of the spreader has an angular inclination to the

25. direction of flow of the particulate material

greater than that of the upper portion and a greater ^" radius thereto such that the lower portion 30 is flared with respect to the upper portion 28.

Connected to the peripheral flange 6 surround- 5. ing the charging inlet 4 of the feeder 2 is a cylin¬ drical extension 32 having at an upper end portion thereof remote from the charging inlet 4 a circular inlet 34. The circular inlet 34 is frusto-conical in shape having at an upper portion thereof an 10. external peripheral flange 36. Inner walls of the circular inlet 34 converge to form an inlet . axially aligned with the charging inlet 4 and the discharge outlet duct 12,

«. Attached to the peripheral flange 36 surround'- 15. ing the circular inlet 34 of the extension 32 is -;an expansion chamber 38 having a substantially cylindrical shape which is bent to form a 90 bend. The expansion chamber 38 includes a lower cylindrical portion 40 of a similar diameter 20. to that of the extension 32 and feeder 2, and an upper frusto-conical portion 42 whose internal diameter decreases progressively from the lower portion 40 toward an inlet 44 remote from the .lower portion 40. The periphery of the inlet is • 25. surrounded by an external flange 46.

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Attached to the external flange 46 of the inlet 44 of the expansion chamber 38 is a feed pipe 48.

The feeder 2 and associated deflector 26 are 5. inserted into an aperture 50 in an upper portion of a vessel 52 such that the deflector 25 and discharge outlet duct 12 project into the vessel 52 and such that the charging inlet 4 of the feeder 2 is external to the vessel 52. A portion 10. of the feeder 2 adjacent the aperture 50 in the upper portion of the vessel 52 is strengthened by webs 54 which extend from the external walls of the feeder and are attached to an outer surface of the vessel 52.

15. Attached to an upper inner surface of the vessel 52 and to the peripheral flange 14 of the discharge outlet duct 12 is a baffle 56 in the form of a plate 58 having a depending cylindrical skirt 60 which surrounds and is spaced apart

20. ^" from the deflector 26 and the discharge outlet duct 12.

In operation, particulate material entrained in air is fed into the feed pipe 48 where on entry into the expansion chamber 38 the particulate 25. material is directed by the shape of the upper

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portion 42 onto the inner walls of the lower portion 40 where a reduction in the speed of flow of the air in which the particulate material is entrained takes place-.

5. The particulate material is then pneumatically conveyed into the circular inlet 34 of the exten¬ sion 32 where due to the shape of the circular inlet 34 the particulate material is channelled away from the inner walls and caused to flow in a

10. uniformly distributed stream adjacent the central axis of the extension 32.

The stream of uniformly distributed particulate material enters the charging inlet 4 of the feeder 2, flows past the support members 20 and the shaft 22

15. towards the discharge outlet duct 12 where due ^" to the shape of the inner walls of the discharge outlet duct 12 the particulate material from the inner walls of the feeder, deflected by impinging on the support members 20 and the shaft 22, is

20. channelled away and formed into a stream of uniformly distributed particulate material. The stream is then conveyed onto the upper portion 28 of the spreader where on impinging on the outer surface thereof the stream is directed radially

25. outwardly then further spread out by impinging upon

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the lower portion of the spreader. The material leaving the portion 30 is uniformly distributed and,impinging on the cylindrical skirt 60, will constitute an annular curtain of uniformly 5. distributed particulate material.

The dimensions of the curtain, particularly the diameter thereof, may be altered firstly by adjusting the position of the deflector 26 in relation to the discharge outlet duct 12 of the

10. feeder for alteration of the internal diameter, and secondly by altering the radius of the cylindrical skirt 60 for alteration of the external diameter. Additionally the dimensions of the curtain may be altered by-altering the

15. velocity of the air in which the particulate material is conveyed. ^;

It should also be appreciated that the feed pipe 48 may be fed directly into the charging inlet 4 of the feeder 2.

20. • It should also be appreciated that the particulate material may be fed into the apparatus . without being entrained in air.

It should further be appreciated that the ^• upper portion 28 and the lower portion 30 of the conical spreader may be constructed from separate castings and be connected together such 5. that the outer surfaces of the lower portion 30 is contiguous with the outer surface of the upper portion 28.

The vessel 52 may be a spray mixing vessel in which the material in the uniform curtain will be 10. mixed with a liquid.

Since the material leaving the lower portion 30 is uniformly distributed, that may serve as the source of a plurality of streams of particulate material having a pre-determined ratio of rates

15. of flow. For instance, to divide the material leaving the portion 30 into eight equal streams, the inner surface of the skirt 60 may be provided with eight similar, radially extending and equiangularly spaced fins, of which two are

20. indicated in broken lines at 62. There will be equal rates of flow between each two adjacent ' pairs of fins and the material may be led away from the bottom of the pair of fins to a point of use. It is envisaged that the particulate

25. material may be fuel, so that eight burners could be equally supplied from a single source of fuel.

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As an alternative, material leaving the portion 30 may discharge directly into the inlet ends of ducts through which it passes to the points of use. The portion 30 might be provided with a downward extension 5. that is provided with grooves that lead to the inlet ends of the ducts.

The material leaving the portion 30 may be divided not only into a number of equal- parts but into parts of different ^' sizes having a pre-determined relation to 10. each other.

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