EA035234B1 - Method for manufacturing a recess plate - Google Patents

Abstract

The invention provides a recess plate (1) designed for use in a filter device for filtering a suspension, the filter device having a stationary head piece and a movable end piece, and a pack including copies of the recess plate (1), having a filter chamber inside the pack, adjoining the recess plate (1), having a first pipe for filling the suspension into the filter chamber, having a filter cloth for collecting a solid content out of the suspension, and having a second pipe for discharging a liquid fraction of the suspension out of the filter chamber as a filtrate, wherein the filter device may be closed before filtering by forcing the end piece in direction of the head piece, and opened after filtering by releasing the end piece, and moving the end piece away from the head piece for removing the filter cake from the filter cloth, and wherein the recess plate (1) has a first surface (9) at the filter chamber and a second surface (10) vis-a-vis the first surface (9), the first surface (9) and the second surface (10) are formed by sheets (2, 3), and the recess plate (1) has a rigid body (15) between the sheets (2, 3). The invention further provides a method for manufacturing the recess plate (1).

Description

Technical field

The present invention relates to a method for manufacturing a recessed plate used in a filtering device for filtering a suspension, which comprises a fixed head part and a movable end part, a bag containing a set of said recessed plates, a filter chamber located inside the bag and adjacent to the recessed plate, a first pipe for filling the suspension of the filtration chamber, a filter cloth for collecting solid contents from the suspension, and a second pipe for discharging the liquid fraction of the suspension from the filtration chamber in the form of a filtrate, wherein the filter device can be closed before filtration by moving the end portion towards the head and opened after filtering by releasing the end part and moving it from the head part to remove the filtered sediment from the filter cloth, and in the specified method, the first sheet is formed to create the first surface of the plate with a recess located at the filter chamber a second sheet to create a second surface of the plate with a recess located opposite the first surface, and foamed material is introduced into the gap between the first sheet and the second sheet, and after curing, this gap is filled with a rigid body.

BACKGROUND OF THE INVENTION

Recessed plates are widely known, in particular from DE 102007027033 A1. The recessed plates must be able to perceive the inevitable pressure drop and return to their original shape after deformation caused by said pressure drop. Such plates must absorb excessive forces during compression and compaction, as well as pressures that arise during the entire operation process, in the absence of compression of the plates. To ensure dimensional accuracy, as well as to install o-rings and membranes, machining should be possible. Fixing and bearing surfaces must be strong enough and should contain internal channels for leachate, flushing medium, air, etc. Currently, such plates with recesses are mainly performed by molding from polypropylene (PP) or even from steel, followed by machining to obtain the final shape.

A limited number of PP plate manufacturers, as well as limited sizes of molding presses, impose limitations from a technical and economic point of view both on the production and on the use of filtering devices.

US 2001/0021428 A1 proposes a method according to the above, in which a shell containing the first and second sheets is made in the form of one sealed hollow part.

Technical challenge

The present invention is the creation of an alternative plate with a recess.

SUMMARY OF THE INVENTION

Based on known methods, in accordance with the present invention, it is proposed to attach the first sheet and the second sheet to a frame containing all the drilled and bored holes necessary for the filtrate, and the foam material together with the frame forms a rigid body.

When using recessed plates in accordance with the present invention, both manufacturers and consumers of filtering devices will no longer depend on the manufacturers of PP plates and their limited production capacities, as well as on molding presses with limited sizes. A recessed plate in accordance with the present invention provides very high strength characteristics under the influence of pressure drops, low weight and the possibility of fully automated production without the need for large and expensive presses, as well as short production cycles.

In a preferred method in accordance with the present invention, the sheet is a fabric. Fabric surfaces provide high bending stress resistance. Alternatively, the sheet may be a plastic film or steel sheet.

In this method, the fabric is preferably reinforced with fibers, while the surface resistance to bending even increases.

In addition, in this method, the fibers are preferably glass fiber. A wide variety of fiberglass hardened fabrics are available on the market, and their processing technologies are well known. Alternatively, the fibers may be, for example, carbon fibers, ceramic fibers, or metal fibers.

In such a method, a recessed plate comprises a sheet of fabric, which is preferably impregnated with a curable resin. Impregnation with a cured resin to impart both dimensional stability and impermeability to the fabric is well known. Alternatively, to impart dimensional stability to the fabric itself, the mold may be lined with an elastic fabric and then filled with curing material to form a rigid body.

In addition, in such a method, the resin is preferably polyethylene. The use of polyethylene (PE) for the impregnation of fabrics is well known, and in this regard, PE is a material having high competitiveness.

- 1,035234

In a preferred method in accordance with the present invention, the first surface and / or the second surface is formed by pressing the corresponding first sheet and / or second sheet to a solid mold. Forming a sheet in a reusable solid mold provides reproducible profiles and mass production.

In such a method, a protective sheet is preferably placed between the corresponding first sheet and / or the second sheet and the solid mold and removed from the first surface and / or second surface after molding. Such protective sheets can be used to prevent contamination of both the mold and the pressure reagent with resin from the first and / or second sheets.

Preferably, in the method of the present invention, the first surface and the second surface are formed by placing the first sheet and the second sheet between two solid molds and introducing a pressure reactant between the first and second sheets. The simultaneous molding of both surfaces makes it possible to simplify the manufacturing process of a plate with a recess and to avoid storage in a warehouse. Alternatively, only one sheet may be formed between the solid mold and the solid lid covering the recess, or two independent sheets may be formed by combining two independent solid molds.

In another preferred method in accordance with the present invention, a fluid is used to press the first sheet and / or the second sheet against the solid mold. The fluid invariably propagates along the profile of the solid mold and, thus, is independent of the specified profile. Alternatively, a male mold (or positive mold) can be used to press the sheets against the mold. Such a male mold may be either rigid or elastic.

In such a method, the fluid is preferably hot water. Hot water can help cure the resin impregnating the sheets.

In addition, in the method in accordance with the present invention, the rigid body is preferably glued to at least one of the first and second sheets. Gluing provides a firm attachment of the rigid body to the sheet (s).

DETAILED DESCRIPTION OF THE INVENTION

Below is a more detailed description of a plate with a recess manufactured in accordance with the present invention, and the corresponding method with reference to the figures, which shows schematic views in sections made through sheets and molds, as well as a plate with a recess obtained during production a four-step process.

In the manufacture of a recess plate 1 in accordance with the present invention, as shown in FIG. 1, a set of two sheets 2, 3 of fiberglass-reinforced fabric impregnated with liquid PE is inserted between two female hard molds 6. Moreover, each of the sheets is lined with two protective sheets 4, 5, made in this case of polymer films.

Then, the solid molds 6 are compressed and fastened to each other (clamps not shown) to ensure sealing of the recesses 7 inside, as shown in FIG. 2.

Then, as shown in FIG. 3, hot water 8 is supplied between two sheets 2, 3, pressing the sheets into recesses 7. After curing PE, hot water 8 is released and solid molds 6 are opened. Until now, the first surface 9 of the first sheet 2 and the second surface 10 of the second sheet 3 facing each other.

Then, sheets 2, 3, having the shape of respective recesses 7 and having stable dimensions, are removed from the solid molds 6. The protective sheets 4 are removed from the backs 11 of the sheets 2, 3 and, as shown in FIG. 4, sheets 2, 3 are turned over so that their backs 11 become facing each other. Sheets 2, 3 are attached to the prepared frame 12, containing all the drilled and bored holes necessary for the filtrate, wash water, air, etc. Then, the hollow space 13 between sheets 2, 3 is filled with structural foam material based on acrylonitrile styrene polymer (SAN) 14, which is characterized by high toughness and impact resistance, for example, material supplied by Gurit Holding AG, Wattwil / Switzerland under the trademark Corecell ™ M. After curing, the foam material 14 together with the frame 12 forms a rigid body 15 of the plate 1 with a recess.

The protective sheets 5 remain on the first surface 9 and on the second surface 10 until delivery.

List of reference designations:

- a plate with a recess;

- first sheet;

- second sheet;

- protective sheet;

- protective sheet;

- solid mold;

- notch;

- water;

- 2 035234

- first surface;

- second surface;

- back side;

- frame;

- hollow space;

- foamed material;

- a rigid body.

Claims (3)

1. A method of manufacturing a plate with a recess used in a filtering device for filtering a suspension, which contains a fixed head part and a movable end part, a bag containing a set of these plates with a recess, a filter chamber located inside the package and adjacent to the plate with a recess, the first pipe for feeding the suspension into the filter chamber, the filter cloth to collect solid contents from the suspension and a second pipe for discharging the liquid fraction of the suspension from the filter chamber in the form of a filtrate, the filter device can be closed before filtering by moving the end part in the direction of the head and open after filtering by releasing the end part and moving it from the head part to remove the filtered sediment from the filter cloth, and in the specified method: a) form a first sheet to create a first surface of the plate with a recess located near the filter chamber, and form a second sheet to create a second surface of the plate with a recess located opposite the first surface, b) moreover, when molding the first sheet and the second sheet, a first sheet (2) of fabric impregnated with a curable resin and a second sheet of fabric (3) impregnated with a curable resin are placed between the first covering solid mold (6) and the second covering hard the mold (6), place the first protective sheet (4) between the first back side (11) of the first sheet (2) of fabric impregnated with the cured resin, and the first covering solid mold (6), place the second protective sheet (4 ) a third protective sheet (5) and a fourth protective sheet (5) are placed between the first sheet (2) between the second back side (11) of the second sheet (3) of fabric impregnated with the cured resin and the second covering solid mold (6) ) from the fabric impregnated with the curable resin and the second sheet (3) of the fabric impregnated with the curable resin, the first female hard mold (6) and the second female hard mold (6) are fastened together to seal the recess (7) between first a second enclosing solid mold (6) and a second enclosing solid mold (6) supply fluid (8) between the third protective sheet (5) and the fourth protective sheet (5) in the recess (7) for pressing the first sheet ( 2) from the fabric impregnated with the cured resin, into the recess (7) before pressing it against the first covering solid mold (6) and to press the second sheet (3) from the fabric impregnated with the cured resin into the recess (7) before pressing it to the second female hard mold (6), curing said curable resin to form a first sheet and to form a second sheet, release said fluid (8) from said recess (7), remove the first sheet from the first female hard mold (6) and the second sheet is removed from the second female hard mold (6), C) place the first back side (11) of the first sheet facing the second back side (11) of the second sheet to form a gap between the first sheet and the second sheet, g) fill the gap between the first sheet and the second sheet with a rigid body. 2. The method according to claim 1, in which the first sheet of fabric is reinforced with fibers. 3. The method according to claim 1 or 2, in which the second sheet of fabric is reinforced with fibers.