RU2282480C2 - Supporting structure for securing filter element - Google Patents

Abstract

FIELD: filtering units for filtration of liquids.

SUBSTANCE: proposed filter element has bearing frame covered with fabric bag or hose. Filter element frame (7) has elongated housing formed by pressure casting which consists of several co-linear sections (13). Frame is provided with several bearing fins (14) running in radial direction from central axis and bearing collar (17) surrounding external edges of fins at upper end. Collar is provided with many bearing guides (18) molded together with it and directed radially inside; inner ends of these guides are engageable with molded body between its adjacent bearing fins.

EFFECT: enhanced strength of frame support; improved service characteristics of filter.

10 cl, 8 dwg

Description

Technical field

The invention relates to a filter element for a liquid filter using a filter medium, such as a bag or sleeve, through which liquid must pass to filter it and in which a filter material such as diatomaceous earth is used to form a layer on the outside of the filter medium when the filter is operating . During operation of the filter, contaminants are deposited on the layer of filter material, and not directly on the filter medium.

In particular, the invention relates to a filter element comprising a support frame that is covered with a woven bag or sleeve, and also to a liquid filter having at least one, and basically, several such filter elements.

State of the art

Filters that use filter media, usually in combination with filter media, to avoid premature clogging of the filter media and thereby extend the life between backwash procedures, usually work according to the principle that when the filter is taken out of service, the filter material and contamination accumulated in it fall to the bottom of the tank. When the filter is put back into operation, the incoming fluid mixes the filter material, usually together with at least a portion of the dirt from the bottom of the filter container, so that the filter material again covers the filter medium.

One such filter, which turned out to be very successful, is described in South African patents Nos. 93/0761 and 2001/21144 in the name of the applicant of this application. This filter uses several substantially parallel elongated filter elements with a plastic molded injection-molded frame, which in its cross section has several longitudinally extending ribs extending from the central axis and whose outer edges support the woven sleeve. The design of the frame is determined, in part, by the design of the tool, and therefore, the operatively upper end of each frame so far has had a molded cuff surrounding the upper end of the frame and having a flange serving as a support for the filter element passing down in its working position relative to the separation plate onto which filter elements are supported in a substantially vertical orientation.

This design, although it is essentially successful, in some cases leads to the appearance of mechanical stresses due to the forces acting on the filter elements; in particular during start-up, and this leads to a breakdown of the frame in the region of its upper end and especially in the cuff. The reason for this is that the upper end is the only support area of the working filter element.

In this case, if the woven bag or sleeve is not properly held tightly at the upper end of the frame, then the sleeve fabric may be pushed under fluid pressure into the flow path between the radial ribs and the cuff, with a subsequent decrease in the flow from the inner space of this filter element and with a decrease in efficiency filtering.

Object of the invention

Accordingly, it is an object of the invention to provide a frame for a filter element configured to harden the frame support at its upper end and, further, to reduce the likelihood of the fabric of the bag or sleeve being pushed into the flow path past the edge of the cuff.

SUMMARY OF THE INVENTION

In accordance with the present invention, a fluid filter element frame is provided comprising an elongated, injection-molded body having a plurality of support ribs extending radially from its central axis and a support collar surrounding the outer edges of the ribs at its operatively upper end, the frame is characterized in that the cuff has at the same time a plurality of radially directed inwardly directed support guides, the inner ends of which interact with the molded body between its adjacent supporting ribs.

Additional features of the invention are a molded body containing a plurality, usually six radial support ribs, in which case the cuff has an equal number of support guides extending inward, the inner edges of which fit tightly into the angle formed between each pair of adjacent support ribs; the support guides are made essentially flat, with a tapering inner edge for tight entry into the angle between the corresponding pair of support ribs; support rails extend downward over the lower end of the cuff; the outer edges of the lower ends of the support rails are bent toward their center; and the upper end of the cuff has a support flange integral at the same time and directed outwardly.

The elongated injection molded case preferably consists of several collinear injection molded sections, each of which has at the same time a support ring interconnecting the outer edges of the support ribs at their operatively lower end, and operatively the upper end, which in the case of all sections except topmost, accommodates the lower edge of the support ring of the next upper section. In this case, the cuff in accordance with the present invention enters the uppermost section, with its integral support rails and a support flange at its upper end. The cuff is connected to the uppermost section by any appropriate means, such as ultrasonic welding, or, more expediently, fusion with a solvent or glue in combination with a tight fit of the cuff on the element.

The invention also relates to filter elements having the aforementioned filter element frame and also a liquid filter containing these filter elements.

To explain the invention, a description of its implementation is given below with reference to the drawings.

List of drawings

1 is a schematic cross-sectional elevational view of a fluid filter assembly used to carry out the present invention.

Figure 2 shows a General schematic cross-section of a vertical projection of a filter element having a frame consisting of several collinear injection molded sections, the upper of which has a cuff according to the invention.

Figure 3 shows a similar, but enlarged and with a spatial separation of the parts, a view of the upper end of the frame of the filter element.

Figure 4 shows a similar vertical projection showing the cuff in the installed position on the uppermost section and the next lower section.

Figure 5 shows a view from the end of a separate cuff.

Figure 6 shows a view from the end of the injection molded frame from its upper end.

Figure 7 shows a view from the end of the cuff in the installed position on the upper end of the corresponding frame.

On Fig shows a partial cross-section of a vertical projection of the lower end of the filter element.

Detailed description of the invention with reference to the drawings

The fluid filter assembly of the present invention typically comprises a round cylindrical container (1) having a concave lower end (2) and, accordingly, a convex cap (3) mounted on the container to be removable. Closer to the upper end of the container, a transverse essentially horizontal dividing plate (4) is mounted on which the upper ends of several essentially vertical elongated filter elements (5) are supported, each of which has filtering means in the form of a woven sleeve (6), resting on its supporting frame (7).

An inlet (8) is located in the side wall of the container closer to its bottom, which has a one-way check valve (9) and through the control valve (10) communicates with the inlet connection (11) for the filtered fluid.

The upper end of the tank has an outlet (12) for the filtered liquid through its side wall located above the level of the separation wall (4).

In the process, the liquid enters through the inlet (8), passes through the woven filter means of the sleeves and then up the filter elements (5) to the upper region of the container (1) on the opposite and therefore upper side of the separation wall (4) and out through the outlet (12 ) In this filter, a finely ground filter medium, which is usually diatomaceous earth, is located on the woven filter medium.

At the end of the filtration cycle, diatomaceous earth and contaminants that fall into it fall to the bottom of the tank and must be mixed substantially uniformly when the filter is put back into operation.

It should be noted that elongated filter elements having support only at their upper ends are subject to certain stresses and deformations, especially during start-up, and that the upper end of these elements must quickly absorb the force exerted on the elements.

The frame (7) is elongated and consists of several collinear injection molded sections (13), most clearly shown in Figure 3, and each of these sections in its cross section has six radial support ribs (14), on the outer edges of which leans a sleeve (6). The supporting ribs (14) are mutually connected at their outer edges by a ring (15) at one end, their lower end, while the ring surrounds the ribs and is molded along with them. The lower end of the composite frame ends in this ring (15a) (see Fig. 8).

According to the invention, the upper end (16) of the uppermost section (13) of the frame has a collar (17) having integral with it, arranged at equal angular intervals, support guides (18) directed inward. The support rails have converging inner edges (19) that fit snugly between the inner ends of the support ribs (14), and therefore each support rail has an angular displacement of about 30 degrees relative to each of two adjacent support ribs by injection molded frame. As shown in FIG. 4, the cuff has an inner flange (20) to which the upper end abuts the injection molded section in the installed position.

The support rails are located essentially below the lower end (21) of the cuff, as indicated by the reference number (22), as a result of which the upper end of each filter element is firmly fixed.

The cuff at its upper end has a support flange (17a) which is also directed outwardly at the same time.

The cuffs are also injection molded from plastic and are permanently attached to the upper end of the corresponding section of the injection molded frame by means such as fusion with a solvent or other bonding agent, or, alternatively, ultrasonic welding. In any case, the cuff is tightly mounted at the end by a pressure-molded frame, while any leakage is eliminated between the two parts.

The frame of the filter element terminates at the lower end with a disk (23) of injection molded plastic having a round edge (24) according to FIG. 8 and described in more detail in South Africa Patent No. 2,000 / 2445 issued to this applicant, the contents of which are incorporated into the description in as a link.

It should be noted that the radially extending support rails, which are in contact with the upper end of the support frame of the filter element, create a very strong attachment of the frame to the separation plate and, according to the tests, the cuff according to the present invention has a strength exceeding the previously used mounting cuffs. In addition, the location of the support rails passing under the lower edge of the cuff itself prevents the filter cloth from being pressed in by the fluid under pressure, the tension of which can weaken, onto the path of the flow passing through the cuff and, as a result, at least partially blocking the flow path.

It should also be noted that in the implementation of the above invention can be made many applications within its scope. In particular, it may be appropriate, for example, to make only three inwardly directed support guides in the case of six support ribs on the frame of the filter element itself, although if the filter fabric is too weakly stretched, it can be pulled into the remaining three holes.

Claims (10)

1. The frame (7) of the liquid filter element, comprising an elongated injection molded body having an upper end and a lower end, a plurality of support ribs (14) extending radially from its central axis and ending radially at the outer edges of the ribs, and a support cuff (17) having an upper end and a lower end and surrounding the outer edges of the ribs on the upper end of the molded body, the cuff having a plurality of support guides (18) radially inwardly aligned with it, inner cones which interact with the molded body between its adjacent support ribs. 2. The frame of the liquid filter element according to claim 1, in which the cuff has several support guides extending inward, the number of which is equal to radially extending support ribs, while the inner edges (19) of the support guides fit tightly into the angle formed between each pair of adjacent support ribs. 3. The frame of the filter element for liquid according to claim 2, in which the design of the support rails is essentially flat and their inner edge has a narrowing for tight fit into the angle between the corresponding pair of support ribs. 4. The frame of the liquid filter element according to claim 1, wherein the support rails extend downward (22) beyond the lower end (21) of the cuff. 5. The frame of the liquid filter element according to claim 1, in which the outer edges of the lower ends of the support rails are bent inward to its center. 6. The frame of the liquid filter element according to claim 1, in which the upper end of the cuff has a support flange (17a) which is also integral with the outside. 7. The frame of the liquid filter element according to claim 1, in which the elongated molded by injection molding body consists of several collinear injection molded sections (13), each of which has a support ring (15) made at the same time, mutually connecting the outer edges of the support ribs at their lower end and the upper end, which in the case of all molded sections except the uppermost, accommodates the lower edge of the support ring of the next upper section. 8. The frame of the liquid filter element according to claim 7, in which the upper end of the uppermost molded section accommodates the cuff with its supporting rails made at the same time. 9. The frame of the liquid filter element according to claim 1, wherein the cuff is connected to the frame using one of the following means: ultrasonic welding, fusion with a solvent and appropriate glue, in combination with a tight fit of the cuff on the frame. 10. A filter element containing filter elements (5) having frames according to any one of claims 1 to 9.

Images