BACKGROUND ART Filter cloths for use in filter presses which comprise side-by-side plates defining filter chambers therebetween are known which comprise separate filter cloths joined together by a barrel neck so positioned as to be registrable with a feed aperture in the plate, the neck being positioned to extend through the feed aperture with the individual filter cloths lying against the respective faces of the press plate.

It is known in the art to provide a barrel neck as a flanged jointing tube and to secure the flanges each to a respective filter cloth by sewing or by utilising polypropylene attachment rings having ferromagnetic particles therein which, on being subjected to induction radiation, serve to melt the polyproylene material of the ring and cause the same to adhere to the flange and to the filter cloth.

The present invention seeks to provide a barrel neck which may be secured to a filter cloth without the need for gluing, sewing or welding.

DISCLOSURE OF INVENTION According to the present invention there is

provided a barrel neck connector comprising two pairs of flanges, said pairs of flanges being provided at opposite ends of a tube, wherein said pairs of flanges are operative to receive a filter cloth therebetween either alone or in combination with at least one seal.

The barrel neck connector of the invention may be secured to a filter cloth without the need for an additional bonding step.

One or more seals may be provided between at least one of the pairs of flanges . The filter cloth may be mounted between the flanges or between one flange and a seal or set of seals provided on the interior face of the other flange or between seals or sets of seals provided on each of the interior faces of the flanges. The seals may comprise an "0" ring and/or a distortable flap. The use of such seals prevents the suspension being filtered from leaking into the filtrate side of the cloth.

A water-swellable gasket may be used as the seal means . As the gasket swells due to contact with water it creates the seal. The water-swellable gasket may comprise an apertured polyethylene sheet formed into a tube and containing swelling agent or a water-swellable yarn.

BRIEF DESCRIPTION OF DRAWINGS

In order that the present invention may be more readily understood specific embodiments thereof will now be described by way of example only with reference

to the accompanying drawings in which:-

Fig. 1 is a vertical cross section through one barrel neck connector in accordance with the present invention;

Fig. 2 shows possible arrangements of sealing rings for use with the barrel neck connector of Fig. 1;

Fig. 3 shows a second barrel neck connector in accordance with the invention; and

Fig. 4 shows one method of locating a seal in position in the barrel neck connector of Fig. 3. BEST MODE FOR CARRYING OUT THE INVENTION Referring to the drawings a barrel neck connector 5 comprises a tube 10 having a pair of circular flanges 11,12,13,14 connected to either end thereof. The connector 5 is made from extrudable or ouldable elastomer. In use a filter cloth 15a, 15b is received between each pair of flanges. A seal 16 is provided between the flanges and the adjacent filter cloth. The seals 16 ensure that the suspension being filtered cannot leak into the filtrate side of the cloth 15. The seal 16 may comprise one or more "0" rings or flaps which could be designed to distort in use so that they provide an effective seal. It should be remembered that there is a positive pressure within each filter press chamber that will serve to force the membrane flaps towards the filter cloth.

It is quite often the case that filtration requires the separation of aqueous liquors

from a slurry. In such circumstances the use of a water-swellable substance as a seal would be particularly advantageous. As water from the filtration process comes into contact with the water-swellable gasket the gasket swells thereby having a gripping effect and providing a seal. The water swellable substance may comprise a non-woven material or a foraminous sheet of plastics film such as that commercially available from Tredegar. Alternatively, as shown in Figures 3 and 4, the water- swellable seal may comprise a water-swellable yarn 17 such as that supplied by Geca. Such a yarn is easy to wind in position as is illustrated in Fig. 4.

It is to be understood that the embodiments described above have been described by way of illustration only. Many modifications and variations are possible.