Filter Drum

Technical Field

The invention relates to a filter drum comprising a supporting frame consisting of faces interconnected by cross beams and having a filter cloth connected to its circumference.

Background of the Invention

In drum-like and other filters, the filter cloth is usually fixed by means of frames attached to the filter body by a large number of screws. This design requires a considerable work expenditure due to the necessity to bore a correspondingly large number of holes, cut threads in them and to fasten the filter cloth in this laborious way. Since the filter cloths must be from time to time exchanged, this time-consuming operation increases the maintenance costs of the filters. Another drawback of the state of art consists in the reduction of the filtering area of the drum.

Disclosure of Invention

The drawbacks of the state of art are removed by the filter drum according to the invention whose principle consists in that the filter cloth is at least on a part of its circumference equipped with a circumferential attachment member inserted into an attachment groove provided at least on the outer side of the cross beams of the supporting frame of the filter drum.

In a preferred embodiment, the attachment groove is provided both on the outer side of the cross beams and on the circumference of the faces of the supporting frame of the filter drum.

The advantage of this arrangement of the filter drum consists in its simple design without screw attachment joints of the filter cloth and, consequently, in reducing both the production and the maintenance costs.

To secure the filter cloth reliably, the circumferential attachment member can be fixed in the attachment groove by an elastic member.

Brief Description of Drawings

An example of embodiment of the invention is illustrated in the annexed drawing in which Fig. 1 is a partial sectional view of the filter drum, and Fig.2 is a sectional view of the filter cloth with the fixed circumferential attachment member.

Modes for Carrying Out the Invention

The filter drum comprises a filter cloth 1_ and a supporting frame consisting of faces 5_ with cross beams 4_ fixed between them. On the outer sides of the cross beams 4 _^ of the supporting frame are provided attachment grooves J3 open from the outer side of the filter drum.

Along the circumference of the faces _5 of the supporting frame of the 'filter drum there are fixed front attachment grooves 7_ which can be replaced in other embodiments by the well known flat attach¬ ment members with screws.

To the circumference pf the filter cloth 1_ is fixed, for instance by gluing, a circumferential attachment member 2_ having in the illustrated example of embodiment a semicircular cross section. This illustratted semicircular cross section of the circumferential attachment member 2_ can be replaced also by another well known shape.

The circumferential attachment member 2_ is seated in the attachment groove 3_ into which it is inserted by its open side. In each attachment groove 2± mounted on the cross beam h_ are Seated opposite each other two circumferential attachment members 2_ having an elastic member 6_ inserted between them so as to secure them against the risk of falling out of the attachment groove 3 _^ .

The shape of the cross section of the elastic member 6^ as well as the shape of the cross section of the attachment groove 3 _^ may differ from the shown embodiment .

The filter cloth 1_ can be seated on well known not represented ribs fixed to the supporting frame of the filter drum.

To exchange the filter cloth 1_, take out the elastic member J5, thus releasing in the attachment grooves 3 _^ , 7_ the circumferential attachment members 2_ that can be then easily taken out of the attachment groove _3, and the filter cloth 1_ removed from the filter drum. After putting a new filter cloth 1_ onto the filter drum, lay the circumferential attach¬ ment members 2_ into the attachment grooves _, 7_, and secure them then against falling out by inserting the elastic element 6^, thus fixing the filter cloth to the filter drum. The filter is then ready for

operat ion .

In another alternative embodiment, the elastic member <_ can be omitted, the circumferential attachment members 2_ being held in the attachment grooves _3_, 7_ by the tension produced by the filter cloth 1.