GB2090765A

GB2090765A - Filter for liquid

Info

Publication number: GB2090765A
Application number: GB8200350A
Authority: GB
Original assignee: Seitz-Werke GmbH
Current assignee: Seitz-Werke GmbH
Priority date: 1981-01-13
Filing date: 1982-01-07
Publication date: 1982-07-21
Also published as: FR2497683A1; DE3100781A1; IT8247511A0; FR2497683B1; IT1147556B; NL8200016A

Abstract

A liquid filter comprises a pressure container (6) with a removable lid (5) and a ventilation duct connection (19), enclosing a vertical hollow shaft (10) which is mounted in the lid (5) and container base (4) and which is rotatable by a drive (12). A stack of flat filter elements (13) is arranged on the shaft (10), and clamped together by a pressing device (16), which comprises four adjustable bolts (24). The tightness of the bolts may be adjusted using a box spanner inserted through connection (19), the filter element stack being rotated to present each bolt to the connection in turn, without any need to remove the lid. <IMAGE>

Description

SPECIFICATION Filter for liquid The present invention relates to a filter for liquid, and has particular reference to means for settable pressing of filter elements of a stack of such elements in a pressure vessel.

Liquid filters of that kind, for example as described in DE-OS 2848 188, are as a rule used for alluvial filtration of beverages, for filtration of low viscosity suspensions in the chemical and pharmaceutical industries and for separation of large quantities of solid matter. After completed filtration, the filter elements, forming the filter packet and representing round alluvial filters, are set into rapid rotation with the pressure vessel closed so that the filtered residues are thrown off the filter elements by centrifugal force and can be removed through an outlet at the base of the vessel. Subsequent cleaning by back-flushing is sufficient to make the filter ready for reuse.

The constant use of such liquid filters requires maintenance operations, which include checking a pressing device for adequate contact pressure against the stack of filter elements in order that the tightness of the stack is maintained. In order to obtain access to the region of setting means of the pressing device for this purpose, it has been necessark to detach and remove the lid of the pressure vessel. Because of the size of such liquid filters, this is possible only with the aid of lifting tools. The maintenance of the pressing device is therefore relatively laborious and time-consuming.

There is accordingly a need for a filter with a filter element pressing device enabling maintenance operations to be performed thereon without the need for removal of a lid of a pressure vessel of the filter.

According to the present invention there is provided a filter for liquid, comprising a pressure vessel provided with a removable lid having closable connection means for a duct, a shaft extending in the vessel and rotatably mounted in the lid and the base thereof, a stack of filter elements removably mounted on the shaft, and a pressing device removably mounted on the shaft between the stack and the lid to exert a settable compressive pressure on the stack, the pressing device comprising setting means operable to set the compressive pressure and so arranged as to be accessible for operation by way of the connection means when open.

Expediently, the setting means of the pressing device and the closable connection means are so constructed and correlated that the opened connection means forms an access into the pressure vessel making possible the actuation of the setting means.

According to a preferred embodiment, the setting means are threaded elements such as screws, which are inclined relative to the shaft and the longitudinal axes of which intersect the lid of the pressure vessel in the region of the connection means when the individual screws are moved into the plane of the connection means by rotary movement of the shaft and pressing device.

After the closure of the ventilation duct, the filter is again ready for use.

An embodiment of the present invention will now be more particularly described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a schematic sectional elevation of a liquid filter according to the said embodiment, and Figure 2 is a detail, to an enlarged scale, of a pressing device of the filter of Figure 1.

Referring now to the drawings, there is shown a liquid filter F comprising a pressure container 6 having a base 4 and a removable lid 5, the filter F being mounted on a frame 3. The base 4 and the lid 5 have bearings 8 and 9, respectively, by means of which a hollow vertical shaft 10 is rotatably mounted in the container. The shaft 10 can be rotationally driven at high speed by a drive 12 arranged in the region below the base 4.

Afilter packet FP consisting of individual plateshaped filter elements 13 arranged in the form of a stack is mounted on the shaft 10. A scraper 15 is fastened to the shaft 10 below the filter packet and a pressing device 16 facing the lid 5 is fastened to the shaft 10 above the filter packet. The lid 5, detachably fastened by means of screws 17, includes a connecting duct, which is closable by means of a ventilating duct 18, in the form of a ventilating stub pipe 19 near the bearing 9.

The pressing device 16 will now be more closely described in connection with Figure 2. A pressure member 20 loosely mounted on the shaft 10 carries a metal baffle plate 21 and has recesses 22, in which engage prejections 23 of setting members. The setting members are constructed as headed screws 24 and are constrainedly guided in respective obliquely outwardly directed seats in a support plate 25 firmly connected to the shaft 10, in the present embodiment by respective threads 26. A pressuretransmitting ring 28 is loosely mounted on the shaft 10 between the uppermost filter element 13 of the filter packet FP and the pressure member 20. In order to attain a uniform contact pressure, four such headed screws 24 are provided, displaced through 90 relative to each other.

As shown in Figure 1, the inclined position of the headed screws and the position of the ventilation stub pipe 19 in the lid 5 are so chosen that the notional longitudinal axis 27 of each screw 24 intersects the lid 5 in the region of the stub pipe 19 as soon as the screw has been moved by a rotary movement of the filter packet into the plane of the stub pipe 19. In this position, the opened stub pipe 19 provides an access into the pressure container 6, making possible the actuation of the screws 24 with the aid of a box spanner 29 illustrated in Figure 1.

The set positions of the headed screws 24 are secured by respective lock nuts 30. These lock nuts are also actuable by a suitable tool by way of the opened ventilation stub pipe 19.

The construction and arrangement of the pressing device enables performance of maintenance and exchange operations thereon without the need for prior removal of the lid from the pressure vessel. In order to obtain access to the region of the setting means, it is merely necessary to open the closable connection means, for example a ventilation duct.

Claims

1. A filter for liquid, comprising a pressure vessel provided with a removable lid having closable connection means for a duct, a shaft extending in the vessel and rotatably mounted in the lid and the base thereof, a stack of filter elements removably mounted on the shaft, and a pressing device removably mounted on the shaft between the stack and the lid to exert a settable compressive pressure on the stack, the pressing device comprising setting means operable to set the compressive pressure and so arranged as to be accessible for operation by way of the connection means when open.

2. A filter as claimed in claim 1, wherein the shaft is hollow and extends vertically in the vessel.

3. A filter as claimed in either claim 1 or claim 2, the setting means comprising a plurality of threaded elements each having a longitudinal axis extending at an angle to the axis of the shaft and each movable by rotation of the shaft and pressing means into such a position that the axis of the respective threaded element intersects the lid in the region of the connection means.

4. A filter as claimed in claim 3, wherein said angle is substantially 15 .

5. A filter as claimed in either claim 3 or claim 4, wherein each of the threaded elements comprises a coupling head for coupling with turning means and a pressure-exerting portion engaged in a recess in a pressure member acting on the stack.

6. A filter as claimed in any one of the preceding claims, the connection means comprising a ventilation opening of the pressure vessel.

7. A filter for liquid, substantially as hereinbefore described with reference to the accompanying drawings.