GB2292977A

GB2292977A - Pressure primer for extracting material from a container

Info

Publication number: GB2292977A
Application number: GB9417889A
Authority: GB
Inventors: John Reilly
Original assignee: Lincoln
Current assignee: Lincoln
Priority date: 1994-09-06
Filing date: 1994-09-06
Publication date: 1996-03-13
Also published as: GB9417889D0

Abstract

A method of extracting material such as adhesive, resin and grease from a container 12 comprises the steps of: providing a follower 30 sized for location within the container; moving the container 12 towards the follower 30 such that the container passes over the follower and the follower contacts the free surface of the material within the container and pressurises the material; drawing material from the container through the follower using a fixed pump 28; and passing the material from the pump through a rigid outlet conduit 36. <IMAGE>

Description

PRESSURE PRIMER This invention relates to improvements in and relating to pressure primers for use in the extraction of material from containers. The invention also relates to a method of extracting material from a container.

Many industries utilise materials such as adhesive, resins, and grease which will only flow, like a viscous liquid, on application of a physical or pressure force.

Such materials are often supplied to the consumer in cylindrical drums. It is not normally possible to pump such materials directly from a drum, this requiring provision of a pressure primer. Conventional pressure primers comprise a heavy frame incorporating a plurality of rams. A frame is mounted on the upper end of the rams and itself provides mounting for a circular follower, sized to fit within the open end of the drum. High pressure pumps are mounted on the upper side of the follower and the pump inlets extend through the follower. A filled drum is mounted on a platform below the follower. The rams are then activated to move the follower downwardly into contact with the free surface of the material contained within the drum. The material is thus pressurised and in this condition may be withdrawn from the drum using the pumps.

As the pumps move with the follower it is necessary to provide flexible conduits from the pump outlets. Due to the high pressures utilised to transfer the material, the flexible conduits must be of special construction and for a given outside diameter the internal diameter is relatively small. In practice, the maximum practical internal diameter of the pump outlet conduits is typically half an inch. This limits the transfer rate of material from the drum and also leads to a considerable pressure drop over the length of the flexible conduits, such that higher rated pumps must be used. In certain applications the handling of materials may be facilitated by heating.

For such applications it is conventional to heat the follower and the material transfer conduits. This adds to the complexity and expense of the primer, and providing effective heating of flexible high pressure conduits is difficult.

It is among the objects of the present invention to obviate and mitigate these difficulties.

According to one aspect of the present invention there is provided a pressure primer for use in the extraction of material from a container, the pressure primer comprising: a follower; a fixed pump having an inlet conduit in communication with the underside of the follower and a rigid outlet conduit; and means for moving a container towards the follower.

According to another aspect of the present invention there is provided a method of extracting material from a container, the method comprising the steps of: providing a follower sized for location within the container; moving the container towards the follower such that the container passes over the follower and the follower contacts the free surface of the material within the container and pressurises said material; drawing material from the container through the follower utilising fixed pump means; and passing the material from the pump means through a rigid outlet conduit.

In use, an open-topped container is mounted on the moving means and then moved towards the follower, such that the follower engages the surface of the material in the container and pressurises the material to facilitate extraction of the material from the container through the pump inlet. As the pump, and preferably also the follower, remain fixed in position the conduits for conveying the material from the pump may be of rigid construction. Such conduits are of far simpler construction that the flexible high pressure hoses required in prior art pressure primers and thus are considerably less expensive to manufacture and require little if any maintenance. Further, the internal diameter of a rigid conduit is far greater than that of a flexible conduit of corresponding external diameter.This allows larger bore conduits to be utilised and thus the pressure drop experienced over a given length of conduit is markedly reduced. In turn, this reduces the pump capacity required to provide a given material supply pressure. The increase in conduit internal diameter also reduces the requirement to heat the follower and conduits, though if heating is required it is straightforward to heat a rigid conduit.

Preferably, the follower is fixed relative to the pump.

Preferably also, the follower and the pump means are mounted on a frame.

In most applications the pressure primer will be utilised to extract material from cylindrical drums and thus the follower will define a circular outer edge, which may be provided with appropriate seals.

Preferably also, the means for moving the container includes a container platform. Preferably also, the container platform is suspended from a lifting frame.

Conveniently, the lifting frame is mounted on one or more rams which may be activated to lift the frame and platform relative to the follower. The ram cylinders may form part of a primer frame and provide mounting for the follower.

According to a still further aspect of the present invention there is provided a pressure primer for use in extraction of material from a container, the pressure primer comprising: a frame; a follower fixed to the frame; a pump fixed relative to the follower and having an inlet in communication with the underside of the follower and a rigid outlet conduit; a container platform; and means for lifting the platform and a container mounted thereon towards the follower such that the follower comes into contact with the free surface of the material in the container and pressurises the material to facilitate withdrawal of the material through the pump inlet.

These and other aspects of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an elevational view of a pressure primer in accordance with a preferred embodiment of the present invention; and Figure 2 is a side view of the pressure primer of Figure 2.

The drawings illustrate a pressure primer 10 in accordance with a preferred embodiment of the present invention. The illustrated primer 10 is utilised to extract material, such as adhesive, from a cylindrical drum 12, as shown in Figure 1 in ghost outline.

The primer 10 comprises a frame 14 including a base 16 and two upstanding side members formed by the cylinders 18, 19 of a pair of high pressure air rams 20, 21. Extending between the upper ends of the rams 20, 21 is a cross member 22 from which a drum platform 24 is suspended.

A further cross member 26 extends between the upper ends of the cylinders 18, 19 and provides mounting for a pump 28 and a circular follower 30. An inlet conduit 32 extends from the pump 28 through the follower 30. A rigid pump outlet conduit 36 extends from the pump 28 to the location where the extracted material is to be utilised.

The follower 30 is sized to fit snugly within the drum 12 and carries two resilient sealing-rings 34, 35 to form a sliding, sealing contact with the drum wall.

In use, the lid of a drum 12 filled with material is removed and the drum 12 placed on the platform 24. The rams 20, 21 are then activated to lift the cross member 22 and platform 22, 24 and thus also the drum 12, such that the drum 12 is lifted over the follower 30, bringing the follower 30 into contact with the surface of the material within the drum 12. This pressurises the material, such that on activation of the pump 28 the material may be drawn from the drum 12.

As the pump and follower 28, 30 locations are fixed, the pump conduits 32, 36 may be of rigid construction, offering considerable advantages over the prior art arrangements in which it was necessary to provide flexible conduits. If the application requires the conduits to be heated this may be achieved quite easily by, for example, wrapping the conduits with a flexible heating element.

A primer 10 as described above was utilised, as described above, to withdraw a heavy mastic sealant (such as used, for example, as a windshield sealant in car production lines) from a drum. In this example a 22j" follower 30 was utilised together with a 75:1 ratio, air operated, high pressure pump 28 providing an output flow of approximately 5.9 litres per minute (based on the displacement of mastic). The pump output conduit had an internal diameter of 14". The downward pressure produced by the rams 20, 21 was 7 bar (approximately 100 psi), such that the delivery pressure of the mastic from the pump 28 was approximately 525 bar (7 bar x 75:1).

It will be clear to those of skill in the art that the above described embodiment is merely exemplary and that various modifications and improvements may be made thereto, without departing from the scope of the invention. In the illustrated embodiment rams lift the drum relative to the follower, however any other suitable sources of motive power may be utilised. Further, the orientation of the above described embodiment, that is with the drum located below the follower, is most commonly used in practice, though clearly a pressure primer in accordance with the present invention could be constructed in which the container was located above the follower and was moved downwardly into contact with the follower.

Claims

1. A pressure primer for use in the extraction of material from a container, the pressure primer comprising: a follower; a fixed pump having an inlet conduit in communication with the underside of the follower and a rigid outlet conduit; and means for moving a container towards the follower.

2. The pressure primer of claim 1 in which the follower is fixed relative to the pump.

3. The pressure primer of claim 2 in which the follower and pump means are mounted on a frame.

4. The pressure primer of claim 1, 2 or 3 in which the means for moving the container includes a container platform.

5. The pressure primer of claim 4 in which the container platform is suspended from a lifting frame.

6. The pressure primer of claim 5 in which the lifting frame is mounted on one or more rams which may be activated to lift the frame and platform.

7. The pressure primer of claim 6 in which the ram cylinders form part of a primer frame and provide mounting for the pump and follower.

8. A method of extracting material from a container, the method comprising the steps of: providing a follower sized for location within the container; moving the container towards the follower such that the container passes over the follower and the follower contacts the free surface of the material within the container and pressurises said material; drawing material from the container through the follower utilising fixed pump means; and passing the material from the pump means through a rigid outlet conduit.

9. A pressure primer for use in extraction of material from a container, the pressure primer comprising: a frame; a follower fixed to the frame; a pump fixed relative to the follower and having an inlet conduit in communication with the underside of the follower and a rigid outlet conduit; a container platform; and means for lifting the platform and a container mounted thereon towards the follower such that the follower comes into contact with the free surface of the material in the container and pressurises the material to facilitate withdrawal of the material through the pump inlet.

10. A pressure primer substantially as described herein and as illustrated in the accompanying drawings.

11. A method of extracting material from a container substantially as described herein.