GB2113805A

GB2113805A - Feed devices for discrete material

Info

Publication number: GB2113805A
Application number: GB08201497A
Authority: GB
Inventors: Brian Michael Carpenter
Original assignee: Coal Industry Patents Ltd
Current assignee: Coal Industry Patents Ltd
Priority date: 1982-01-19
Filing date: 1982-01-19
Publication date: 1983-08-10
Also published as: GB2113805B

Abstract

The device (1) comprises a rotatable valve member (2) having an arcuate plate (4) carried by a radial arm (6). A deflector (22) is provided downstream of the valve member (2) and is movable with the member (2) to define a variable flow path. The movement of the member (2) through the discrete material is facilitated by the variation in the flow path size beneath the member (2). <IMAGE>

Description

SPECIFICATION Improvements in or relating to feed devices This invention concerns improvements in or relating to feed devices intended for use with discrete material.

More particularly, the invention has reference to such devices employed for affording control over the flow of discrete material.

Devices of the character indicated for use in conjunction with reservoirs, for example hoppers or silos, which contain a head of the discrete material to be discharged according to a desired pattern, for example, intermittent flow. It is thus necessary to achieve, in practice, a reduction or cut-off in flow having regard to a demand for the material.

Conventionally, this reduction or cut-off is achieved by using a slide valve the line of action of which is laterally through the material discharging from the hopper or silo, but a considerable degree of effort has to be expended in moving the valve.

An object of the present invention is to provide an improved feed device which requires less effort than that required for conventional devices employed for the same purpose.

According to the invention there is provided a feed device including a rotary valve member for mounting in association with a housing defining a flow path therethrough, whereby, in use, rotation of the member varies the size of the flow path, and a deflector member associated with and located downstream of the rotary valve member, the deflector member forming a movable boundary of at least a part of the flow path in the housing.

Conveniently the value member may be of arcuate form, for example an arcuate plate carried by a radial arm mounted for rotation about its free end. The radial arm may be attached to a shaft rotatably mounted on or in the housing and has a drive member provided externally of the housing.

The drive member may be adapted for manual or power operation.

The valve member may be mounted on the radial arm externally of the housing and adapted upon rotation to move into and out of the housing through the flow path.

As a preferred alternative the valve member may be mounted within the housing which, in the vicinity of the member, is constructed to define the flow path adjacent a compartment into which the member is retracted when the flow path is not obstructed by the member, that is when partial or complete closure is not required. In the preferred alternative a plate is arranged part way across from one wall of the housing terminating therein to define the flow path between its free edge and the opposing wall. A divider is situated beneath the level of the plate to constitute a boundary for the flow path and to define a limit of the compartment. A slot is provided either in the divider or between the divider and plate, through which slot the valve member passes upon rotation thereof.The divider may extend from directly beneath the plate to the level of the shaft on which the radial arm is mounted.

The deflector member may also be attached to the shaft and; is rotatable with the valve member, such that upon movement of the valve member, the deflector member moves to vary the size of the flow path downstream of the valve member.

By way of example only, one embodiment of feed device according to the invention is described below with reference to the accompanying drawings in which Figure 1 is a side sectional view showing a first operational position; Figure 2 is a side sectional view showing an intermediate operational position; and Figure 3 is a side sectional view showing a second operational position.

Referring to the drawings, a feed device is shown at 1 and includes a valve member 2 formed of an arcuate plate 4 carried by an apertured radial arm 6 which is attached to a rotatable shaft 8. The shaft 8 extends through a housing 10 in which the member 2 is disposed, the housing 10 being constructed in the vicinity of the member 2 to define a flow path 1 2 from the compartment 14. A divider 1 6 separates the flow path 1 2 from the compartment 1 4 and extends from the level of the shaft 8 to but spaced from a plate 1 8 which is arranged part way across the interior of the housing 1 0. A slot 20 is defined between the lower surface of the plate 1 8 and the top edge of and out of the flow path 12.

A deflector 22 is attached to the shaft 8 and in the first operational position aligns with the divider 1 6 to define at least part of the flow path 12.

In operation, discrete material, for example coal, is held in a hopper (not shown) having an outlet with communicates with the upper end of the housing 10 as viewed in the drawings. In the first operational position the valve member 2 shown in Figure 1 the feed device is set to allow free passage of coal through the flow path 12, since the plate 4 is fully retracted into the compartment 14, and the deflector 22 is vertically disposed in line with the divider 1 6. When sufficient coal has passed through the device, and a static column has built up within the flow path 1 2 and it is desired to close the flow path, the valve member 2 is rotated by means of the shaft 8 moving in an anti-clockwise direction as viewed in Figure 2.At the same time, the deflector 22 moves in unison with the valve member 2 and in so doing changes the dimension of the flow path 12 (see Figure 2). The effect of this change is to allow some movement in the material downstream of the valve member 2 which causes corresponding flow in the vicinity of the arcuate plate 4. The valve member 2 can, therefore, move more easily across the flow path 1 2 through a body of coal which is to some extent in a flow condition that it could through a completely static column.Upon rotation, which can be effected manually be a handle (not shown) mounted on the shaft 8 externally of the housing 10, plate 4 passes through slot 20 out of the compartment 14 and cuts through the column of coal within the flow path 12, but in so doing the leading edge 24 of the plate 4 describes and arc and thus in combination with the curved form of the plate, a low resistance to movement is experienced. Any fine material entering compartment 1 4 may escape therefrom easily through the apertured radial arm 6. Upon further rotation of the valve member 2 to a fully closed position (Figure 3), the flow path 1 2 is completely shut off, a stop 28 on the wall 26 being provided for the plate 4. In this second operational position no coal can pass below the member.

This isolation is of particular import where combustible materials are being held in the feed device when it is used in conjunction with combustion equipment of their ancillaries, to prevent burn back. Alternatively, the device of the present invention may be used as a feeder for a conveyor, for example a screw conveyor of an underfeed stoker or a screw elevator/conveyor. In this instance, feed to the conveyor can easily be stopped by the device 1 merely by rotating the shaft 8 to move the valve member 2 from its first operational position (Figure 1) to the third (Figure 3). As has been indicated, because of the deflector member 22 allowing movement of material in the flow path 1 2, the plate 4 can move easily through the column of material, and substantially less effort is needed to effect closure than would be required for a conventional slide valve.

Although reference has been made to the use of the device for coal feeding, it is to be understood that the feed device can be used for other discrete materials.

Claims

1. A feed device including a rotary valve member for mounting in association with a housing defining a flow path therethrough, whereby in use, rotation of the member varies the size of the flow path, and a deflector member associated with and located downstream of the rotary valve member, the deflector member forming a movable boundary of at least part of the flow path in the housing.

2. A feed device according to claim 1 in which the member is an arcuate plate.

3. A feed device according to claim 2 in which the arcuate plate is carried by a radial arm mounted for rotation about the end thereof remote from the plate.

4. Afeed device according to claim 3 in which the radial arm is attached to a shaft rotatably mounted on or in the housing.

5. A feed device according to any one of the preceding claims in which the valve member is mounted within the housing.

6. A feed device according to claim 5 in which the housing is constructed to define a flow path adjacent a compartment into which the member is adapted to be retracted out of the flow path.

7. A feed device according to claim 6 in which a plate is arranged partially across the housing from one wall thereof to define the flow path between the free edge of the plate and an opposing wall of the housing.

8. A feed device according to claim 7 in which a divider is situated to one side of the plate to constitute a boundary for the flow path and the compartment.

9. A feed device according to claim 8 in which a slot is provided in the divider or between the divider and the plate, through which slot the valve member passes upon rotation thereof.

10. A feed device according to claim 1, 2, 3 or 4 in which the valve member is rotatably mounted externally of the housing and is adapted to move into or out of the housing.

11. A feed device substantially as hereinbefore described with reference to Figures 1, 2 and 3 of the accompanying drawings.