GB2374864A

GB2374864A - Hopper outlet valve

Info

Publication number: GB2374864A
Application number: GB0109951A
Authority: GB
Inventors: Terence Albert White; Stephen John Waller
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-04-24
Filing date: 2001-04-24
Publication date: 2002-10-30
Also published as: GB0109951D0

Abstract

A hopper outlet valve comprises a series of slots in a seat or seats 1 and a series of slots in a closure member or members 2 with the closure(s) reciprocated relative to the seat(s) by a drive 3. The valve can be of V-shaped cross-section as shown or of U-shape, (Fig 3).

Description

A DEVICE FOR CONTROLLED DISPENSING AND SHUT-OFF OF FLUENT SOLIDS FROM A STORAGE Various devices are presently available for controlled dispensing and shut-off of fluent solids.

Rotary Valves and their variants have pockets mounted on a horizontal shaft, or occasionally on a vertical shaft as described in the Basil K Leong patent GB 2007190 A, and empty by gravity or pneumatic means. Other devices used for the purpose are based upon the Archimedian screw principle wherein fluent solids are conveyed in a tube or trough to a point of discharge. Controlled discharge is provided by positive displacement of the solid by rotation of the screw form. There are various other devices that use the same basic principle of dispensing discrete quantities of fluent material via an exit opening. A rotating disk has also been employed, as in some agricultural processes, but this relies upon a secondary shut-off device to prevent uncontrolled discharge (leakage) of material. There are additionally limitations as to the particle size range this type of device can handle satisfactorily.

The purpose of our invention is to provide a device to dispense fluent solids from storage in a controlled manner and that has improved transfer and dispersion of the discharged solids compared to the existing devices described. The device described herein is fitted to the outlet of a gravity discharged storage hopper, silo or other fluent solid material containment.

According to the present invention an apparatus is provided for controlled dispensing and shutoff of fluent solids with improved dispersion. This is achieved by means of shaped sliding surfaces in intimate contact with each other, both having apertures that are covered and uncovered by means of reciprocating movement. The top of the device has the entry point from and means of attachment to the fluent solids storage container. Aligned, the apertures allow fluent material particles discharged from storage to fall through the exposed openings. When the apertures are not aligned the openings are covered and a positive shut-off is achieved, thus preventing discharge of the fluent solids. The elements are so formed as to contain the material until controlled reciprocating movement aligns openings in both sliding and fixed surfaces at the same time thus allowing the fluent solids to discharge from the storage through the invention.

The shape of the openings is not critical since the fundamental objective is to provide discharge when the openings are aligned and shut-off when the openings are not aligned and hence covered.

The particle size range of the fluent solids and the maximum rate at which they are to be discharged determines the dimensions of the invention and the number, size and shape of the openings. Rate of discharge is controlled by selection of period and frequency for the reciprocating movement of the inner element. Any prime mover capable of imparting the required reciprocating force required to activate the device, which includes operation of the device by manual means, can be used. Control of period and frequency of the reciprocating prime mover may be provided by mechanical means or by any suitable timing device that has control and adjustment of frequency and period for the reciprocating movement e. g. electronic or fluidics process logic control devices, timers and relays, and other similar control devices.

To enable the present invention to be more readily understood examples of possible shape and form of the device are described. Alternative geometry for the shape and form of the elements and apertures are employed to satisfy the characteristics of the fluent solid to be discharged. However, the basic concept of the operation must be maintained i. e. controlled period and frequency of reciprocating motion to open and close apertures for fluent material to pass through.

Example 1 The shape and form described in Figure 1 comprises an enclosed V-shaped housing 1, with an inlet connection from the storage 8. The housing is fitted with a sliding element 2 connected to a reciprocating drive device 3 using an adjustable length connector 4 to enable transfer of reciprocating motion for operation of the invention. Slots 7 are formed in both the outer housing 1 and the sliding element 2. When the slots are aligned the fluent material passes through from its storage 8. When the slots are out of alignment, such that no opening exists, the material flow is shut-off. The adjustable element of connector 4 provides the connection between the reciprocating drive device 3 and the sliding element 2. This adjustable element of connector 4 is additionally used to ensure slots are correctly positioned before use. The adjustable element has a screwed element 5 with a left-hand thread at one end and a right-hand thread at the other that enables the connector 4 to be shortened or lengthened when rotated. A locking device 6 prevents the threaded element 5 from rotating accidentally when the connector 4 is motivated by the reciprocating drive device 3.

To ensure the opening area remains constant the slot pitch is the same for the fixed housing 1 and the sliding element 2 but the solid landing area in between the slots is wider than the width of the slot e. g. a 5mm wide slot and a 10mm wide landing. This allows for a certain amount of misalignment that may occur when the reciprocating drive mechanism does not accurately align the openings. The desired constant rate of flow is governed by setting the period and frequency of the reciprocating motion and thus the time and frequency of the slots being opened or closed. The slots in both the sliding and the fixed elements may be angled, as shown in Fig. 2. This enables the flow of fluent material to start slowly and increase until the maximum open area is achieved and then reduce until the openings are closed. The angled slots thus enable a graduated discharge for improved control and accuracy of dispensing.

Example 2 The shape and form described in Figure 3 comprises a semi-circular shaped housing 1 fitted with a sliding element 2 connected, as described in Example 1., to a device 3 by an adjustable length connector 4 that will enable reciprocating motion for operation of the invention via the connector 4.

Slots 7 are formed in both the outer housing 1 and the sliding element 2. When the slots are aligned the fluent material passes through from its storage 8 as shown in Fig. 1. of Example 1. When the slots are out of alignment, such that no opening exists, as shown in Fig. 1. of Example 1, the material flow is shut-off. To ensure the opening area remains constant the slot pitch is the same for the fixed housing 1 and the sliding element 2 but the solid landing area in between the slots is wider than the width of the slot e. g. a 5mm wide slot and a 1 Omm wide landing. This allows for a certain amount of misalignment that may occur when the reciprocating drive mechanism does not accurately align the openings. The desired constant rate of flow is governed by setting the period and frequency of the reciprocating motion and thus the time and frequency of the slots being opened or closed.

Example 3 The slots in both the sliding and the fixed elements may be angled, as shown in Fig. 2. of Example 1. The angle of the slots in the sliding elements are at the same, but at an opposing angle to, those in the fixed element. This enables greater control over the rate at which the open area increases thus allowing the flow of fluent material to start slowly and increase until the maximum open area is achieved and then reduce again as the openings are closed. Angled slots thus provide for improved control and accuracy for dispensing the fluent solid material.

Claims

Claims 1. An apparatus for controlled dispensing and shut-off of fluent solids with improved dispersion, the said apparatus achieving its function by means of shaped sliding surfaces in intimate contact with each other, both having apertures that are covered and uncovered by means of reciprocating movement in conjunction with enclosed containment for the fluent material until apertures are aligned wherein the fluent material particles fall through the exposed openings and when the apertures are not aligned the openings are covered providing positive shut-off and containment to prevent the uncontrolled release of fluent solids.
2. An apparatus according to Claim 1 wherein the shape of the openings in both sliding and fixed elements are angled such that discharge of the fluent solid can be finely controlled.
3. An apparatus according to Claim 1 and Claim 2 wherein the prime mover providing the reciprocating motion is any device capable of imparting the reciprocating force required to activate the device via a connecting element, which includes operation of the device by manual means.
4. An apparatus according to Claim 3 wherein control of period and frequency of the reciprocating movement is controlled by an electronic or fluidics process logic control device, timers and relays and other similar control devices, including manually controlled means.
5. An apparatus according to Claim 1 that is used to provide controlled dispensing of fluent solid material from any size or form of containment wherein controlled discharge from that containment to a further operation or process is required.
6. An apparatus for controlled dispensing, shut-off and containment of fluent solids with improved dispersion as herein described with reference to examples as illustrated in the accompanying drawings.