GB2159724A

GB2159724A - Filter press

Info

Publication number: GB2159724A
Application number: GB08414610A
Authority: GB
Inventors: Kenneth Lewis Amos
Original assignee: Johnson Progress Ltd
Current assignee: Johnson Progress Ltd
Priority date: 1984-06-08
Filing date: 1984-06-08
Publication date: 1985-12-11
Also published as: GB8414610D0

Abstract

A filter press is provided in which at least one of the end frames, preferably both, is constituted by a hollow pressure vessel 11,12 adapted to be pressurised by fluid to balance the compressive pressure to which the filter plates 10 are subjected. The pressurising fluid is preferably the fluid product to be filtered but it may be a separate and different fluid. The two end pressure vessels 11,12 are in communication, there being means provided to ensure equalisation of pressure therein. <IMAGE>

Description

SPECIFICATION A filter press This invention relates to filter presses such as are employed, inter alia, in dewatering sludge, sewage and coal tailings.

Generally, such a filter press comprises a series of filter plates to each of which a suitable filtering medium is fastened to cover the plate area, the filter plates being compressed between two substantial end frames by hydraulic rams or powered screws. The material to be filtered can be fed through the compressed filter plates in various ways, for example through the axial centre of the plates or through the corners of the plates or otherwise. The filter press has drainage facilities for egressing liquid and the solid matter retained by the filter plates is removed by releasing the end frames so that relative movement therebetween can be effected to permit the individual filter plates to be moved by suitable equipment to allow removal of the solid matter therefrom.After all solid matter is removed the filter plates are again clamped up together between the end frames and the filter press is ready for operation once again.

The end frames are generally substantial castings or fabrications in terms of both weight and cost of production and the object of the present invention is to provide a filter press which when compared with an existing filter press, size for size, is substantially lighter in weight, is cheaper to manufacture and offers a wider range of closing pressures.

According to the present invention there is provided a filter press in which at least one of the end frames, preferably both, is constituted by a hollow pressure vessel adapted to be pressurised by fluid to balance the compressive pressure to which the filter plates are subjected.

Preferably, the pressurising fluid is the fluid product to be filtered but it may be a separate and different fluid.

Preferably, the two pressure vessels are in communication, there being means provided to ensure equalisation of pressure therein.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side elevation of the filter press; and Figure 2 is an end elevation.

The filter press comprises a filter plate pack generally indicated at 10 disposed and compressible between two end frames which, in accordance with the present invention, are constituted by two closed hollow pressure vessels 11, 12, each being of part-spherical configuration with a flat pressure face 11 A, 12A.

The customary filter plate moving equipment or gear is generally indicated at 13.

The pressure vessel 11 is the fixed or stationary end frame while the pressure vessel 12 is, as can be seen from Fig. 1, the movable or tightening end frame.

Each pressure vessel 11, 12 has fixed thereto four brackets or lugs 11 B, 1 2B spaced 90 apart.

Each corresponding pair of brackets 11 B and 1 2B is connected by a rod or shaft 14 connected at the pressure vessel 11 end of the filter press to a double acting hydraulic cylinder 15.

The inlet feed for the material to be filtered is generally indicated at 16 and, in this example, is central of the filter plate pack 10.

Pressuring fluid, which may be product fluid is delivered into pressure vessel 11 via a pipe 17 which is connected via a pipe 18 having a flexible end section 19 to the pressure vessel 12. The flexible end section 19 is, of course, necessary to cope with movements of the pressure vessel 12.

The pipes 17, 18 are connected to a sealed pressure transmitter 19 to which is connected, firstly, an equalising fluid supply 20 and, secondly, a branch pipe 21 from the product feed 16 serving to provide an impulse pressure feed to the transmitter.

Thus both pressure vessels 11, 12 are equally pressurised one with another and with the tightening pressure of the filter press.

It will be manifest that the use of closed hollow pressure vessels as the filter press end frames gives the advantages aforementioned when compared with existing filter presses.

1. A filter press in which at least one of the end frames is constituted by a hollow pressure vessel adapted to be pressurised by fluid to balance the compressive pressure to which the filter plates are subjected.

2. A filter press as claimed in claim 1, in which both end frames are constituted by hollow pressure vessels.

3. A filter press as claimed in claim 1 or 2, in which the pressurising fluid is the fluid product to be filtered.

4. A filter press as claimed in claim 1 or 2, in which the pressurising fluid is a different one from the fluid product to be filtered.

5. A filter press as claimed in claim 2 or 3, in which the interiors of the filter press and one end pressure vessel are connected by a fluid product delivery pipe.

6. A filter press as claimed in claim 5, in which said one end pressure vessel is connected to the other pressure vessel by a fluid product delivery pipe.

7. A filter press as claimed in claim 6, in which the delivery pipe connecting the end pressure vessels comprises a flexible end section connected with the other end pressure vessel to compensate for movement of the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A filter press This invention relates to filter presses such as are employed, inter alia, in dewatering sludge, sewage and coal tailings. Generally, such a filter press comprises a series of filter plates to each of which a suitable filtering medium is fastened to cover the plate area, the filter plates being compressed between two substantial end frames by hydraulic rams or powered screws. The material to be filtered can be fed through the compressed filter plates in various ways, for example through the axial centre of the plates or through the corners of the plates or otherwise. The filter press has drainage facilities for egressing liquid and the solid matter retained by the filter plates is removed by releasing the end frames so that relative movement therebetween can be effected to permit the individual filter plates to be moved by suitable equipment to allow removal of the solid matter therefrom.After all solid matter is removed the filter plates are again clamped up together between the end frames and the filter press is ready for operation once again. The end frames are generally substantial castings or fabrications in terms of both weight and cost of production and the object of the present invention is to provide a filter press which when compared with an existing filter press, size for size, is substantially lighter in weight, is cheaper to manufacture and offers a wider range of closing pressures. According to the present invention there is provided a filter press in which at least one of the end frames, preferably both, is constituted by a hollow pressure vessel adapted to be pressurised by fluid to balance the compressive pressure to which the filter plates are subjected. Preferably, the pressurising fluid is the fluid product to be filtered but it may be a separate and different fluid. Preferably, the two pressure vessels are in communication, there being means provided to ensure equalisation of pressure therein. An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side elevation of the filter press; and Figure 2 is an end elevation. The filter press comprises a filter plate pack generally indicated at 10 disposed and compressible between two end frames which, in accordance with the present invention, are constituted by two closed hollow pressure vessels 11, 12, each being of part-spherical configuration with a flat pressure face 11 A, 12A. The customary filter plate moving equipment or gear is generally indicated at 13. The pressure vessel 11 is the fixed or stationary end frame while the pressure vessel 12 is, as can be seen from Fig. 1, the movable or tightening end frame. Each pressure vessel 11, 12 has fixed thereto four brackets or lugs 11 B, 1 2B spaced 90 apart. Each corresponding pair of brackets 11 B and 1 2B is connected by a rod or shaft 14 connected at the pressure vessel 11 end of the filter press to a double acting hydraulic cylinder 15. The inlet feed for the material to be filtered is generally indicated at 16 and, in this example, is central of the filter plate pack 10. Pressuring fluid, which may be product fluid is delivered into pressure vessel 11 via a pipe 17 which is connected via a pipe 18 having a flexible end section 19 to the pressure vessel 12. The flexible end section 19 is, of course, necessary to cope with movements of the pressure vessel 12. The pipes 17, 18 are connected to a sealed pressure transmitter 19 to which is connected, firstly, an equalising fluid supply 20 and, secondly, a branch pipe 21 from the product feed 16 serving to provide an impulse pressure feed to the transmitter. Thus both pressure vessels 11, 12 are equally pressurised one with another and with the tightening pressure of the filter press. It will be manifest that the use of closed hollow pressure vessels as the filter press end frames gives the advantages aforementioned when compared with existing filter presses. CLAIMS

7. A filter press as claimed in claim 6, in which the delivery pipe connecting the end pressure vessels comprises a flexible end section connected with the other end pressure vessel to compensate for movement of the latter relative to the filter press.

8. A filter press as claimed in claim 6 or 7, in which the two fluid product delivery pipes are connected to a sealed pressure transmitter to which is connected an equalising fluid supply and the fluid product via a pipe to provide an impulse feed to the pressure transmitter.

9. A filter press, substantially as hereinbefore described with reference to the accompanying drawings.