GB2329178A

GB2329178A - Storage and discharge means for particulate material

Info

Publication number: GB2329178A
Application number: GB9719322A
Authority: GB
Inventors: George William Snape
Original assignee: Process Link Ltd
Current assignee: Process Link Ltd
Priority date: 1997-09-12
Filing date: 1997-09-12
Publication date: 1999-03-17
Anticipated expiration: 2017-09-12
Also published as: GB2329178B; GB9719322D0

Abstract

A storage and discharge means for particulate material comprises a moveable storage assembly 1 releasably mounted on a stationary discharge assembly 10 such that one stationary discharge assembly may be used for unloading a plurality of moveable storage assemblies. The storage assembly comprises a first frame 4 and a storage container 2 with a flexible lower portion 5 leading to a discharge opening 6 controlled by a valve 7. The discharge assembly comprises a second frame 23 and a vibration unit 11 arranged such that vibrations, for preventing bridging of the particulate material upon unloading, are transmitted to the flexible lower portion when the storage assembly is mounted on the discharge assembly. Preferably a seal 16, e.g. an inflatable annular seal, is provided between the two assemblies and the valve is a slide valve which is controlled by an actuator 20, e.g. via a pneumatic cylinder, on the discharge assembly. Preferably the valve is attached to the first frame by a vibration transmitting resilient connection 5 and tensioning means 30, e.g. screw tighteners, are provided on the first frame for adjusting the tension in the resilient connection. Preferably a flexible duct 17, leading to a rigid tube 18 having a flow control means, is provided on the outlet of the discharge assembly.

Description

APPARATUS FOR DISCHARGING PARTICULATE MATERIAL The invention relates to an apparatus for discharging particulate material.

US 4273266 discloses an apparatus comprising a bulk container having a discharge opening in its base, and a vibratory tray feeder for conveying material from the discharge opening of the container to a second discharge opening. The tray feeder has an inlet connected to the discharge opening of the container by a flexible portion. To assist the passage of the material from the material to the tray feeder, the tray feeder is vibrated in a manner which transmits vibrations through the flexible portion of the connecting means to the container. The container may be a fixed container or part of a mobile unit in which the container and the tray feeder are supported on the same frame.

According to the present invention there is provided an apparatus for discharging particulate material comprising: a) a first mobile frame housing (i) a storage container (ii) a lower flexible portion of the storage container, said portion leading towards a discharge opening, and (iii) valve means for regulating flow of material through the discharge opening, the resilient portion being arranged so that vibration thereof facilitates flow of the material through the discharge opening, and b) a second frame on which the first frame is releasably mounted, the second frame comprising a discharge station at which material from the container is discharged into receiving means, the second frame housing vibration means arranged to be drivingly coupled to transmit vibrations to the resilient portion.

The use of a valve means permits the regulation of the flow of material through'the discharge opening.

Preferably, the discharge station has an actuator arranged to be drivingly coupled to the valve means. The advantage is thereby gained that the second frame, which is conveniently a static unit comprises both an actuator for operating the valve means and an actuator for the vibration means. A plurality of first mobile frames may then be used with the second frame, each first mobile frame comprising a relatively simple structure to which it is unnecessary to provide electrical or other power supply, such power being supplied only to the second frame.

Conveniently, in order to avoid loss of material, a seal unit forms a seal between the discharge opening and a duct for the flow of material through the discharge station.

The valve means is conveniently a slide valve. A particularly suitable slide valve assembly is disclosed in patent application number WO 96/23 153.

The invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a side elevation of an apparatus for discharging particulate material, according to the present invention, having a first mobile frame and a second frame; and Figure 2 is a plan view of the second frame of the apparatus, shown in Figure 1.

Figure 3 is a side elevation of the first mobile frame of Figure 1 with various parts thereof separated.

Referring to Figure 1, the apparatus has a first mobile frame 1 and a second base frame 2, also shown in Figure 2. The mobile frame 1 houses a storage container 2 suitable for storing particulate material. The lower part 3 of the storage container is conical, decreasing in size from top to bottom, as shown in the drawing. The discharge angle of the conical part 3 is approximately 60". The conical part of the storage container terminates in a large flanged aperture 4. A lower, conical flexible portion 5 is sealingly attached to the flanged aperture 4, and leads to a discharge opening 6. The flexible portion 5 is, for example, of fabric material with a suitable lining appropriate to the product to be handled and its cone angle is greater than that of the conical part 3. A suitable lower conical flexible portion is described in US 4273 266. Flow of material through the discharge opening 6 is regulated by means of a slide valve 7 having an outlet flange (not shown). The valve 7 is a slide valve assembly as disclosed in WO 96/23 153 adapted so that it can be operated automatically or remotely.

The valve 7 is secured to the mobile frame on a leaf spring suspension 8. The use of a slide valve of this type enables the valve to be accurately located with respect to the discharge opening 6, and so to regulate flow of material through the opening.

The base frame 9 is a painted mild steel frame which may be floor standing or, if required, mounted on a steel structure to give elevation. The base frame may alternatively be galvanised steel, stainless steel or any other suitable material. The mobile frame 1 is releasably mounted on the base frame 9. The base frame comprises a discharge station 10 by which material from the storage container 2 is discharged into receiving means (not shown). The base frame houses vibration means 11, in the form of an adjustable amplitude electrically powered vibration unit. Altematively, the vibration unit could be pneumatic, particularly for use in hazardous areas. The vibration means 11 is resiliently mounted on the base frame, and has a coupling arrangement for vibrationally coupling the mobile frame 1 when the mobile frame 1 is mounted on the base frame 9. In operation of the valve 7, a spigot 12 on the valve engages with a docking unit 13 on the base frame; additionally, docking pins 14 on the vibration unit drivingly engage with the spring suspension 15 of the valve. This coupling enables transmission of vibrations from the vibration unit to the lower, conical resilient portion 5.

The base frame also has an annular inflatable seal unit 16 which is able to create a substantially secure seal with the outlet flange of the valve of the mobile frame. When inflated, the diameter of the seal 16 matches the diameter of the discharge opening 6.

A flexible duct 17 extends through the discharge station 10, leading from the inflatable seal 16 to a fixed metal tube 18 through which material passes toward the receiving means (not shown). The metal tube 18 has a level control which detects product and feeds back a signal to the vibration unit, to control the vibration of the vibration unit and increases or decreases the flow of material which is, in part, determined by the vibrations.

The base frame 9 also comprises a mechanism 20 for automatically and/or remotely operating the slide valve. The mechanism 20 comprises a pneumatic cylinder 21. Further, the base frame has a control system (not shown) for controlling the pneumatic, electrical and electronic signals to the base frame.

In the embodiment of Figure 3 the mobile frame 1 comprises an upper 25, an intermediate 26 and a lower 27 part. The upper 25 and intermediate 26 parts of each comer post are secured together with a screw thread fixing 28. The intermediate 26 and lower parts 27 are secured together with a screw thread fixing and adjustment 30. The adjustment 30 allows the correct tension to be applied to the conical flexible portion 5 which ensures the proper transmission of vibration in the portion 5. The tension may need to be adjusted from time to time to maintain efficiency.

Further, the adjustment 30 allows the upper 25 and intermediate 26 parts of the mobile frame 1 to be lowered, releasing the tension on the conical flexible portion 5 for its removal and replacement when required.

In use, the mobile frame is hoisted or lifted by fork truck over the frame and lowered into position. Shaped corner footcups 19 on the base frame ensure that the handpost 12 on the valve enters the docking unit 13, and that the docking pins 14 on the vibration unit engage with the spring suspension 15 of the valve.

Corner posts 22, 23 of the frames locate together securely and releasably so that the mobile frame is mounted on the base frame.

Once the mobile frame is lowered onto the base frame the two frames become as one. A signal that the frames are engaged causes the inflatable seal 16 to inflate, so that an effectively 'dust tight" seal is formed between the valve 7 and the discharge station 10.

Following a signal to commence the discharge cycle, the mechanism 20 for automatically and/or remotely operating the slide valve is activated, unlocking and opening the valve 7.

When the valve 7 is fully opened it activates a slide valve open limit switch, which in turn actuates the level control.

If material flows freely from the mobile frame, this is registered by the level control.

If the material bridges, the lack of flow of product is registered by the level control.

Actuation of the vibration means 11 takes place, and vibrations are transmitted to the lower conical resilient portion 5. This breaks the bridging, the material flows freely through the outlet 6 and the duct 17, and is registered by the level control which sends a signal to stop the vibration of the vibration means 11.

The assembly is designed so that the vibrations are strongest nearest the discharge opening 6, and the valve 7. The vibration is transmitted upwards via the flexible conical portion 5, and is reduced in intensity higher in the mobile frame due to damping by the leaf spring suspension 8. The more gentle vibration higher in the mobile frame ensures that any weaker bridges in the larger diameter areas of the conical portion are also broken. Thus material can flow toward the discharge opening 6 where the vibrations are stronger.

The sequence allowing the material to flow freely continues until the container 2 is empty.

When the vibration means 11 has vibrated for more than a pre-set number of seconds, the container is deemed to be empty. The vibration means 11 is de-activated, and the mechanism 20 for automatically and/or remotely operating the slide valve 7 is activated and closes and then locks the valve.

A container empty signal is given. The operator lifts and removes the mobile frame 1 with the empty container 2. This signals and deflates the inflatable seal 16.

The mobile frame with an empty container can be replaced by a frame with a full container and the process is then repeated.

Claims

CLAIItIS

1. Apparatus for discharging particulate material which comprises a first mobile frame housing a storage container, lower flexible portion of the storage container, said portion leading towards a discharge opening, and valve means for regulating flow of material through the discharge opening, the resilient portion being arranged so that vibration thereof facilitates flow of the material through the discharge opening, and a second frame on which the first frame is releasably mounted, the second frame comprising a discharge station at which material from the container is discharged into receiving means, the second frame housing vibration means arranged to be drivingly coupled to transmit vibrations to the resilient portion.

2. Apparatus according to Claim 1 wherein the discharge station has an actuator arranged to be drivingly coupled to the valve means.

3. Apparatus according to Claim 1 or 2 wherein the second frame is a static unit.

4. Apparatus according to Claim 1,2 or 3 comprising a plurality of said mobile frames selectively mounted on the first frame to be coupled to the first frame in the operative discharge position.

5. Apparatus according to any of the preceding claims wherein a seal unit forms a seal between the discharge opening and a duct for the flow of material through the discharge station.

6. Apparatus according to any one of the preceding claims wherein the valve means is a slide value.

7. Apparatus according to Claim 5 wherein the seal unit means comprises an annular inflatable sealing member on the second frame.

8. Apparatus according to any one of the preceding claims wherein the valve means is connected to the mobile frame through a resilient connection by which vibration is transmitted to said frame.

9. Apparatus according to any one of the preceding claims comprising docking means on the mobile frame and on the second frame whereby the frames are located relative to one another when the mobile frame is mounted on the second frame and whereby the drive is transmitted from the second frame to the resilient portion and to the valve means on the mobile frame.

10. Apparatus according to any one ofthe preceding claims comprising tensioning means on the mobile frame for adjusting the tension in the resilient portion.

11. Apparatus according to any one of the preceding claims wherein the second frame comprises a flexible duct extending from the discharge opening towards an outlet opening.

12. Apparatus according to Claim 11 wherein the flexible duct leads to a rigid tube incorporating flow control means.

13. Apparatus for discharging particulate material substantially as described with reference to the drawings.