WO1999036155A1

WO1999036155A1 - Frame for mounting of filter bags

Info

Publication number: WO1999036155A1
Application number: PCT/SE1998/002425
Authority: WO
Inventors: Ove Gidlund
Original assignee: Nordfilter Ab
Priority date: 1997-12-30
Filing date: 1998-12-22
Publication date: 1999-07-22
Also published as: AU2194199A; SE9704915D0

Abstract

This invention relates to a supporting frame with a square or rectangular design, intended to be used in a filter element of cassette-type and comprising four essentially straight supporting frame parts, which filter element comprises a filter material in the form of one or more filter bags, the filter material being positioned nearest the opening of the filter bags being intended to be kept fastened by clamping in the supporting frame. According to the invention the supporting frame is characterized by the combination of the following features: each supporting frame part (2-5) has such a design that it comprises two main profiles (8, 9) which are articulately connected to each other, the two profiles being able to be separated from each other and to give place for the filter material (12) and to be closed for fastening the same by clamping; the main profiles (8, 9) are provided with locking means (10, 11) which are intended in a cooperating manner to hold the main profiles in a mutual locking position; the one main profile (8) is provided with a clamping means (13), which in the locking position of the main profiles is intended to cooperate with a corresponding means (14) of the second main profile (9) for fastening the filter material by clamping.

Description

Frame for mounting of filter bags

This invention relates to a supporting frame with a square or rectangular design, intended to be used in a filter element of cassette-type and comprising four essentially straight supporting frame parts, which filterelement comprises a filter material in the form of one or more filter bags, the filter material being positioned nearest the opening of the filter bags being intended to be kept fastened by clamping in the supporting frame, and each supporting frame part having such design that it has two main profiles, which are provided with locking means that are intended to retain the main profiles in a mutual locking position. In later times higher and higher requirements have been directed on the possibility to recycle products like for instance filter elements. Therefore, it is nowadays a requirement that the supporting frame shall be able to be separated from the filter material when the filter element shall be destructed. Moreover, the supporting frame shall be designed in that way that it shall be simple to be able to quickly put in and fasten the filter material in the supporting frame by locking when manufacturing the filter cassette.

A supporting frame according to the introductory part is previously known by Swedish patent No. 504.124. This known supporting frame, however, has supporting frame parts, each one of which comprising three main profiles, namely a centrally positioned waist part and two side leg parts connected to this one. This results in the troublesome drawback that the filter material is not fastened by clamping in a desirable way, because the risk is great that the two co-operating side leg parts are not sufficiently well adapted to each other in order to have intended effect.

This invention relates to a supporting frame which is more effective to use and more inexpensive to produce than the described, known supporting frame, and which besides that fulfils the requirements that have been directed above. Due to this new invention, the filter material is clamped in an extremely secure way between a male means of the one main profile and a corresponding female means of the other main profile. The invention is made possible by a supporting frame of the kind mentioned by way of introduction, which has the features mentioned in the claims. A preferred embodiment of the invention shall be described more closely below with reference to the accompanying drawings, where Fig. 1 shows a filter element comprising a plurality of filter bags, put together, which are fastened to a supporting frame, schematically drawn up, according to the invention, Fig. 2 shows a section through a supporting frame part in Fig. 1, seen in the direction of the arrows II-II, Fig. 3 shows a section through the supporting frame according to the invention, seen in the direction of the arrows HHII, yet without filter material and in open position, and Fig. 4 shows a section of the filter element at the arrows IN-IN, an elongated strip, functioning as a cramp, lying in an inactive, extracted position. In Fig. 1 is shown the construction of a filter element according to the invention having a square or rectangular supporting frame 1 , which comprises four supporting frame parts 2-5, connected together, and carries a plurality of filter bags 6, put together. The supporting frame is in a conventional way provided with a plurality of rod-like means 7, connecting two opposite supporting frame parts 3, 5 with each other. The purpose of these means 7 is to support the filter bags and prevent these ones from collapsing in strong draught.

In Figs. 2 and 3 the construction of the frame parts 2-5 of the supporting frame is shown more closely. Each frame part 2-5 has two main profiles 8, 9, which are articulately connected to each other, the two parts being able to be separated from each other and to give place for the filter material and to be closed for fastening the same by clamping.

Each one of the main profiles 8, 9 is provided with a hook-formed locking means 10, 11, which are intended in a co-operating manner to hold the main profiles in a mutual locking position, which is shown in Fig. 2. From this figure is also apparent how the filter material 12 is held fastened by clamping between the mentioned main profiles. Thus, the one main profile 8 has a male means in the form of a projection 13, which in the locking position of the main profiles is intended to be forced into a corresponding female means in the form of a recess 14 in the other main part 9, the filter material being held fastened by clamping in a secure way between the mentioned means 13, 14.

As is apparent from Figs. 2, 3 is the one main profile 9 somewhat thicker than the other main profile 8. The reason why is that this profile 9 shall be able to take up the ends 15 of the rod-like means 7, which connect two opposite frame parts together. In Fig. 3 is shown how the end 15 of the mentioned means 7 is clamped in between two portions 16, 17 of the thicker main profile. In the shown embodiment the one portion 16 comprises a tongue-like means, which contributes to the fastening by clamping of the rod-like means 7, whereas the other portion comprises a planar supporting portion 17.

When manufacturing filter elements in a conventional way, a first portion 18 of the first filter pocket 19 is sewn together with a first portion 20 of the other filter pocket 21, and this sewing is located to the area in the front of the rod-like means 7. This sewing extends along essentially the entire length of the mentioned means 7 and is made at each means 7 so that all filter bags are connected with each other.

According to this invention can this time-consuming working moment be eliminated. The solution of this problem is shown in Fig. 4. In this figure is shown how two portions 22, 23 of two adjacent filter bags 24, 25 are brought into contact with the front side of the rod-like means 7, which has an oval section with a spiked outer part. In this connection the mentioned portions 22, 23 are laid in an overlapping position. Thereafter, a robust cramp 26 in the form of an elongated strip, which extends along essentially the entire length of the rod-like means 7, and which has an inner portion with the design which is like that one of the section of the rod-like means 7, is fastened by clamping on the rod-like means 7 in such a way that portions of the two filter bags 24, 25 get a place between the cramp and the means 7 and accordingly is fastened against the same by pressing. The cramp 26 is suitably provided with spikes, directed backwards, for a secure fastening of the filter portions against the means 7 by clamping.

The supporting frame according to the invention is made of a suitable metallic or non-metallic material like for instance aluminium or plastic.

The invention is of course not limited to shown and mentioned embodiment but can be modified within the scope of the following claims.

Claims

1. A supporting frame with a square or rectangular design, intended to be used in a filter element of cassette-type and comprising four essentially straight supporting frame parts, which filterelement comprises a filter material in the form of one or more filter bags, the filter material being positioned closest to the opening of the filter bags being kept fastened by clamping in the supporting frame, and each supporting frame part having such a design that it has to main profiles, which are provided with locking means that are intended to retain the main profiles in a mutual locking position, c h a r a c t e r i z e d by the combination of the following features: - The two main profiles (8, 9) are articulately connected to each other, the two profiles being able to be separated from each other and give place for the filter material (12) and to be closed for fastening the filter material by clamping between themselves;

- The one main profile (8) is provided with a male means in the form of a clamping means (13), which in the locking position of the main profiles is intended to co-operate with a corresponding female means (14) of the other main profile (9) for fastening the filter material (12) by clamping.

2. A supporting frame according to claim 1, c h a r a c t e r i z e d in that the clamping means of the one main profile (8) comprises a projection (13) which is intended to co-operate with a recess (14) of the other main profile.

3. A supporting frame according to claim 1 or 2, a plurality of rod-like means

(7) connecting two opposite supporting frame parts (3, 5) and supporting the filter bags, c h a r a c t e r i z e d in that the other main profile (9) is thicker than the first one (8) and has an opening limited by two portions (16, 17), into which the one end (15) of the means (7) is clamped.

4. A supporting frame according to claim 3, each rod-like means (7) having a front side, which is directed from the filter bags, c h a r a c t e r i z e d in that the rod-like means (7) has an oval-like section with a spiked outer part, and that a cramp (26) in the form of an elongated strip, which extends along essentially the entire length of the rod-like means (7), and which has an inner portion with a design which is like that one of the section of the rod-like means (7), is intended to be fastened by clamping on the mentioned means (7) and by that to be able to fasten portions of adjacent filter bags (24, 25) by clamping, which have been laid in an overlapping position against the means (7) in question.