GB1566159A

GB1566159A - Plate filter press

Info

Publication number: GB1566159A
Application number: GB1624977A
Authority: GB
Original assignee: Passavant Werke AG and Co KG; Passavant Werke Michelbacher Hutte
Current assignee: Aqseptence Group GmbH
Priority date: 1976-04-27
Filing date: 1977-04-19
Publication date: 1980-04-30
Also published as: CH616597A5; FR2349352A1; DE2618437A1; DE2618437C2; JPS6236727B2; JPS52131269A; FR2349352B1; CA1088874A

Abstract

The filter plate (1) has a central hanger (2) which permits the filter plate to be slid perpendicularly to the plane of the drawing. In addition, guides (3) are provided on the top plate corners to prevent pendulum motion. Each guide has a guide rod which is surrounded by a guide block closed on all sides. The block is composed of a U-shaped bottom piece and a top closing piece joined to the bottom piece. Screws serve for the attachment, which screws extend through the closing piece and through the bottom part and engage in the filter plate (1). In a plate filter press of this type, the cleaning operation can be carried out by the spraying device without additional assembly work. <IMAGE>

Description

(54) PLATE FILTER PRESS (71) We, U. PASSAVANT AG MICHEL BACHER HiiTTE, a German Body Corporate, of 6209 Aarbergen 7, German Federal Republic, trading as PAS SAVANT-WERKE MICHELBACHER HÜTTE, do hereby declare the invention, for which we pray that a patent may be granted to us, and the methocl by which it is to be performed, to be particularly described in and by the following statement: The invention relates to a plate filter press comprising centrally suspended filter plates, guide means to prevent the plates swinging back and forth, and a flushing device includ ing a spray tube, the spray tube being insertable from below between adjacent filter plates.

In plate filter presses, for example for the dewatering of sewage sludges, it is known to open the filtration chambers by pulling adjacent filter plates apart so that the filter cakes can drop out downwards. However, solid remnants adhere to the filter cloths covering the filter plates. These remnants gradually decrease the permeability of said filter cloths. Accordingly, the cloths are periodically sprayed with pressurized water so as to remove the remaining solids.

This flushing operation is carried out by moving a spray tube into the space between two adjacent, separated filter plates. The simplest structural and kinematic conditions arise if the spray tube is arranged horizontally and guided at both ends. It is then introduced from below into the open filtration chambers.

However, up to now, this flushing operation has been a time-consuming procedure.

This is primarily due to the guide means which serve to prevent the filter plates from swinging back and forth while they are being moved away from each other, i.e. being separated. These guide means are in the form of rods extending in the vicinity of the lower plate corners over the entire length of the plate filter press and are engaged from above by lugs arranged on the filter plates. Such an arrangement necessitates that the rods are released and disengaged from the lugs before the spray tube could be operated. This means that sometimes the filter cakes drop onto the lowered rods and spatter partly sideways from the plate filter press thereby contaminating the environment.

According to the invention there is provided a plate filter press comprising filter plates each being suspended from the middle of the top edge, guide means to prevent the plates swinging to and fro, and a flushing device including a spray tube mounted beneath the plates so that when the plates are to be cleaned the spray tube is moved between spaced adjacent filter plates, the guide means for each filter plate being arranged at or adjacent at least one of the upper corners of the plate.

The guide means for each plate preferably comprises at least one completely closed guide block attached to the filter plate and surrounding an associated guide rod. This surrounding of the rod on all sides ensures optimum guidance. Furthermore, the blocks may serve as suspension means for the filter plates in case the central suspension should break for any reason. The filter plates are prevented from dropping down and repair work can be postponed until a favourable opportunity arises. The blocks may be detachably secured to the filter plates so as to be replaced whenever necessary.

Each guide block preferably comprises a U-shaped base portion and a locking portion secured thereto. This makes possible a particularly simple construction. Also, screw means may be provided fastening not only the locking portion to the base portion but also the base portion to the respective filter plate.

It is an additional advantage that the surfaces of each guide block directed towards the associated guide rod are bevelled in the manner of a cutting edge, thus reducing friction inside the guide block. This feature is particularly advantageous in connection with the inner surface of the locking piece. Friction may be further reduced by the guide blocks being made of plastics material.

By way of example, a specific embodi ment in accordance with the invention will be described with reference to the accom p::r.yiPg drawings in which: Figure 1 is a front view of part of a plate filter press; Figure 2 is an enlarged front view of one of the guide means of the press of Figure 1; and Figure 3 is a section along line Ill-Ill in Figure 2.

According to the drawings, a filter plate 1 of a plate filter press has a suspension 2 at the middle of its top edge making possible an upward vertical displacement of the filter plate. In addition, the upper corners of the plate 1 are provided with guide means 3 to prevent oscillatory movements.

The design of each guide means 3 is apparent from Figure 2 and Figure 3. Each guide means comprises a guide block 5 which is closed on all sides and surrounds an associated guide rod 4. The block comprises a U-shaped base portion 6 and an upper locking portion 7 connected with the base portion. Fastening of the block 5 is effected by bolts 8 extending througll the locking portion 7 and through the base portion 6 into the respective filter plate 1.

Figure 3 shows that the surfaces of the guide block 5 directed towards the guide rod 4 are bevelled in the manner of a cutting edge. The guide block is made of plastics material.

In certain cases it may be sufficient to provide only one guide means in the vicinity of one upper corner of the filter plate.

In all cases it is desirable that the central suspension 2 and the guide means 3 are kept clear of the lower area of the filter plate so that a horizontally arranged spray tube of a flushing device (not shown) can be introduced from below between adjacent filter plates and parallel to the drawing plane of the drawings.

An advantage of the filter plate described above is that the cleaning operation can be carried out by means of the flushing device without any additional installation work being required.

Also the spray tube of the flushing device can easily be inserted from below into the open filtration chambers. A further advantage is that the filter plates even during the washing operation (which, as is well known, entails stepahise displacement of the filter plates) are guided to prevent them from swinging back and forth. Still further, the above-mentioned contamination of the environment while the filter cakes are dropping out is prevented.

It will also be appreciated that the guide means are no longer spaced at the maximum distance from the central suspension. This would be the case if the guide means were arranged at the lower plate corners. Now it has been found, not only in large but also in medium and small filter plates, that the space between the upper plate corners and the central suspension means is large enough to accommodate guide means which will prevent oscillation of the plates.

WHAT WE CLAIM IS: 1. A plate filter press comprising filter plates each being suspended from the middle of the top edge, guide means to prevent the plates swinging to and fro, and a flushing device including a spray tube mounted beneath the plates so that when the plates are to be cleaned the spray tube is moved between spaced adjacent filter plates, the guide means for each filter plate being arranged at or adjacent at least one of the upper comers of the plate.

2. A presse as claimed in claim 1, wherein the guide means for each plate comprises at least one completely closed guide block attached to the filter plate and surrounding an associated guide rod.

3. A press as claimed in claim 2, wherein each guide block comprises a U-shaped base portion and a locking portion secured thereto.

4. A press as claimed in claim 2 or claim 3, wherein the surfaces of each guide block directed towards the associated guide rod are bevelled in the manner of a cutting edge.

5. A press as claimed in any one of claims 2 to 4, wherein the guide blocks are made of plastics material.

6. A plate filter press substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. ment in accordance with the invention will be described with reference to the accom p::r.yiPg drawings in which: Figure 1 is a front view of part of a plate filter press; Figure 2 is an enlarged front view of one of the guide means of the press of Figure 1; and Figure 3 is a section along line Ill-Ill in Figure 2. According to the drawings, a filter plate 1 of a plate filter press has a suspension 2 at the middle of its top edge making possible an upward vertical displacement of the filter plate. In addition, the upper corners of the plate 1 are provided with guide means 3 to prevent oscillatory movements. The design of each guide means 3 is apparent from Figure 2 and Figure 3. Each guide means comprises a guide block 5 which is closed on all sides and surrounds an associated guide rod 4. The block comprises a U-shaped base portion 6 and an upper locking portion 7 connected with the base portion. Fastening of the block 5 is effected by bolts 8 extending througll the locking portion 7 and through the base portion 6 into the respective filter plate 1. Figure 3 shows that the surfaces of the guide block 5 directed towards the guide rod 4 are bevelled in the manner of a cutting edge. The guide block is made of plastics material. In certain cases it may be sufficient to provide only one guide means in the vicinity of one upper corner of the filter plate. In all cases it is desirable that the central suspension 2 and the guide means 3 are kept clear of the lower area of the filter plate so that a horizontally arranged spray tube of a flushing device (not shown) can be introduced from below between adjacent filter plates and parallel to the drawing plane of the drawings. An advantage of the filter plate described above is that the cleaning operation can be carried out by means of the flushing device without any additional installation work being required. Also the spray tube of the flushing device can easily be inserted from below into the open filtration chambers. A further advantage is that the filter plates even during the washing operation (which, as is well known, entails stepahise displacement of the filter plates) are guided to prevent them from swinging back and forth. Still further, the above-mentioned contamination of the environment while the filter cakes are dropping out is prevented. It will also be appreciated that the guide means are no longer spaced at the maximum distance from the central suspension. This would be the case if the guide means were arranged at the lower plate corners. Now it has been found, not only in large but also in medium and small filter plates, that the space between the upper plate corners and the central suspension means is large enough to accommodate guide means which will prevent oscillation of the plates. WHAT WE CLAIM IS:

1. A plate filter press comprising filter plates each being suspended from the middle of the top edge, guide means to prevent the plates swinging to and fro, and a flushing device including a spray tube mounted beneath the plates so that when the plates are to be cleaned the spray tube is moved between spaced adjacent filter plates, the guide means for each filter plate being arranged at or adjacent at least one of the upper comers of the plate.