GB2452812A

GB2452812A - Apparatus for controlling discharge of flowable material from a container

Info

Publication number: GB2452812A
Application number: GB0814328A
Authority: GB
Inventors: Charles Bernard Lee
Original assignee: MATCON
Current assignee: MATCON
Priority date: 2007-08-07
Filing date: 2008-08-05
Publication date: 2009-03-18
Anticipated expiration: 2028-08-05
Also published as: GB0715388D0; CH697750A2; GB0814328D0; CH697750B1; GB2452812B

Abstract

Apparatus 1 for gravity discharge of flowable particulate material through an outlet 2 of a container 3 which outlet 2 is closed by a valve 4, comprising an actuator 5 to open the valve 4 and a metering device 6 in the flow path of the material from the outlet 2 to provide for a constant rate of delivery. The actuator may be within a body 12, with a drive system also within the body 12 or a housing 17 attached to the body 12. The metering device 6 may be a screw within a conduit, with gear arrangement 19 within the body 12 or housing 17 and a drive shaft 18 at 90 degrees to the actuator movement. The material may be weighed to control the metering device 6 and hence the material flow. The metering device 6 may be driven by an air motor or a servo motor, while the actuator 5 may comprise a probe which may be conical (8 in Fig 1) or flat 23 operable via bellows (13 in Fig 1). The apparatus may include a conical hopper 7.

Description

1 2452812

MATERIAL HANDLING APPARATUS

The invention relates to material handling apparatus, particularly to such apparatus as is used for gravity discharge of flowable particulate material through an outlet of a container for such material, which outlet is normally obturated by a hollow cone valve member.

It will be understood that the expression flowable particulate material includes granules, particles of material, powders, pellets, slurries, and the like which are flowable under gravity through a container outlet. Such material is usually discharged through an, in use, lower outlet aperture of a storage container such as a silo, hopper or intermediate bulk container (IBC), which aperture is usually obturated by a valve means which in some cases can be conical or frustoconical. The valve means obturates the aperture by setting down on a hopper outlet of the container. The valve is raised by means, usually a bellows situated therebelow to form an annular outlet through which material flows during discharge. A vibrator can be used to ensure that there is no tendency in the material to "bridge" or form "rat holes" which otherwise lead to uneven flow or, in the former case no flow at all. Sometimes too it is necessary to adjust the lift of the valve means, but this can be difficult as the bellows is either inflated, or deflated, so providing only extreme end positions and no intermediate positions.

According to the invention there is provided material handling apparatus for gravity discharge of flowable particulate material through an outlet of a container for such material which outlet is obturated by a valve, comprising actuator means to open the valve and a metering device in the flow path of material from the outlet to provide for a constant rate of delivery of material. Thus, using the invention it is possible to obtain a relatively low but continuous discharge rate of material which increases the controllability of the discharge process.

The actuator may include a body, and it is preferred that drive means for the metering device is disposed within the body, or a housing attached to the body. This provides for a combined discharge and metering device, saving space and complexity.

The metering device may comprise a metering screw, the metering screw being disposed within a conduit for material flow. This is a convenient metering device.

The metering screw-may include a driven shaft with a gear arrangement within the body or housing. Preferably, the gear arrangement will comprise a bevel gear arrangement, the drive means being at substantially 90° to the lift direction of the actuator.

In certain embodiments, the metering screw is generally vertically oriented. In other embodiments, the metering screw is generally horizontally oriented.

It is preferred that the apparatus includes means to monitor the weight of material flowing from the outlet, and means to vary the operation of the metering device in response to signals from the weight monitor to control the rate of flow.

Preferably, the metering device will be driven by an air motor or a servo motor.

The actuator may comprise a probe operable via bellows means.

According to a second aspect of the invention there is provided a material storage and handling device, comprising a container including an outlet for discharge of material by gravity, the outlet obturated by a valve, the device including apparatus as set out hereinabove.

According to a third aspect of the invention there is provided a method of handling flowable particulate material comprising the use of apparatus or a device as set out here above.

The invention will further be described by way of example with reference to the following drawings in which: Figure 1 is a part longitudinal sectional view of apparatus according to a first embodiment of the invention; Figure 2 is a part longitudinal sectional view of a second embodiment of apparatus according to the invention; and Figure 3 is a part longitudinal sectional view of a third embodiment of apparatus according to the invention.

Referring to the drawings, there is illustrated material handling apparatus I for gravity discharge of flowable particulate material through an outlet 2 of a container 3 for such material which outlet 2 is obturated by a valve 4, comprising actuator means 5 to open the valve 4 and a metering device 6 in the flow path of material from the outlet 2 to provide for a constant rate of delivery of material.

Referring in particular to the first embodiment of the invention illustrated herein which is shown in Figure 1, the material handling apparatus includes a conical discharge hopper 7 within which is mounted the actuator means 5. The actuator means 5 comprises a probe 8 which consists of a conical head 9 with a cylindrical skirt 10.

Within the head 9 a vibrator device 11 is situated, as is well known in the art. The actuator further includes a body 12 which is fixed in place and supports a bellows 13.

The bellows is attached to an upper plate 14 which is attached to head 9. As described so far, the apparatus is conventional and well known in the art.

The apparatus is provided with a metering device 6 in the form of a conveyor or metering screw which includes a cylindrical driven shaft 15 attached to a screw part 16.

The discharge hopper 7 terminates at its lower (as viewed) end in a cylindrical section which is just wider than the width of the screw part 16 which passes into it.

The cylindrical driven shaft 15 of the metering screw 6 passes into the actuator body 12 via an extension housing 17 about two thirds of the way up its length. This obviates any tendency of the screw to cant under load. The shaft is provided with a gear acted on by drive means in the form of a drive shaft 18 and bevel gear 19 passing into the apparatus 1 perpendicular to the cylindrical driven shaft 15 from outside of the discharge hopper 7. A servo motor 20 drives the drive shaft 18.

As will be appreciated; the cylindrical driven shaft 15 rotates within the body 12 of the actuator 5 and extension housing 17 and to facilitate that rotation thrust bearing 21 is provided.

Referring now to Figure 2 a second embodiment of apparatus according to the invention is illustrated. The apparatus 1 is essentially as described with reference to the previous example; however in this embodiment the probe is not conical but takes the form of a cap 22 having a flat upper surface 23. This drawing also illustrates the outlet 2 of the container 3 with valve 4 in situ in the obturating position.

Thus, apparatus embodying the invention allows a high degree of control to be exercised over the delivery of material from the container 3. In use, the probe 8 is raised by the bellows 13 to contact the underside of the valve 4 and raise it upwardly into the container 3. This opens an annular space around its periphery through which particulate material in the container 3 passes down into the discharge hopper 7. It will be noted that the bellows is isolated from the product flowing into the discharge hopper 7 by a shroud 23. Material from the outlet 2 passes down into the discharge hopper 7 coming to rest on the screw 16 which can be operated simultaneously to rotate and thereby deliver material from the bottom of the discharge hopper 7 in a controlled metered way. In practice, the actuator would be operated to maintain a small head of material above the screw.

Referring now to Figure 3, this shows apparatus generally as per Figure 1, but with the screw part 16 arranged generally horizontally such that it operates as a side outlet screw.

Notably, this allows the separation of the screw apparatus from the actuator body 12, thus reducing the number of component parts and in particular removing the need for bevel gear 19.

Claims

1. Material handling apparatus for gravity discharge of flowable particulate material through an outlet of a container for such material which outlet is obturated by a valve, comprising actuator means to open the valve, and a metering device in the flow path of material from the outlet to provide for a constant rate of delivery of material.

2. Apparatus according to claim 1, the actuator including a body, drive means for the metering device being disposed within the body, or a housing attached to the body.

3. Apparatus according to claim I or claim 2, the metering device comprising a metering screw.

4. Apparatus according to claim 3, the metering screw being disposed within a conduit for material flow.

5. Apparatus according to claim 3 or claim 4, the metering screw including a driven shaft with a gear arrangement within the body or housing.

6. Apparatus according to claim 5, the gear arrangement comprising a bevel gear arrangement, the drive means being at substantially 900 to the lift direction of the actuator.

7. Apparatus according to any preceding claim, including means to monitor the weight of material flowing from the outlet, and means to vary the operation of the metering device in response thereto to control the rate of flow.

8. Apparatus according to any preceding claim, the metering device being driven by an air motor or a servo motor.

9. Apparatus according to any preceding claim, the actuator comprising a probe operable via bellows means.

10. Material handling apparatus, substantially as hereinbefore described with reference to the accompanying drawings.

11. A material storage and handling device, comprising a container including an outlet for discharge of material by gravity, the outlet obturated by a valve, including apparatus according to anyone of claims Ito 10.

12. A method of handling flowable particulate material comprising the use of apparatus according to anyone of claims I to 11.