Repair method for filter cake of diaphragm filter press

Abstract

The invention discloses a method for repairing a filter cake of a diaphragm filter press. The method comprises the following steps: feeding a feed liquid into a filter chamber and boosting to form a filter cake; when a filter cake is subjected to liquid or gas cross-flow, a pressure medium is conveyed into the diaphragm plate, so that the diaphragm sheet is expanded to compress the space of the filter chamber; and after the liquid or gas finishes flowing, starting the diaphragm to squeeze and extrude the filter cake for dehydration. When liquid or gas flows through a filter cake, a diaphragm plate in the filter plate assembly has a certain drum membrane pressure relative to the liquid or gas, so that the space in the filter chamber is always kept in a relatively compact state relative to the volume of the filter cake; in addition, cracks can be completely eradicated under the pressure action of the diaphragm piece drum membrane on the diaphragm plate, or the cracks can be rapidly and completely repaired after being generated, the risk that a filter cake cracks does not need to be worried about in the flow penetrating process, namely, the pressure or the flow speed of liquid or gas in the flow penetrating process does not need to be reduced, and efficient flow penetrating work can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of filter pressing, in particular to a method for repairing filter cake of a diaphragm filter press. Background Art

[0002] In the prior art, when the diaphragm filter press enters the filter cake liquid or gas flow process, the washing liquid or compressed air can easily crack the filter cake under high-speed flow conditions when the liquid or gas flows through the filter cake. After the filter cake has cracks, the washing liquid or compressed air does not flow through the filter cake according to the preset process path, but leaks out from the cracks, resulting in reduced washing and backwashing dehydration effects or direct failure. The prior art usually equips the filter press washing liquid or compressed air inlet with a throttle valve to limit its flow rate, but this not only seriously reduces the work efficiency, because the filter cake is always kept in a closed filter chamber in the working state of the diaphragm filter press, the generation of cracks cannot be observed, and the causes of filter cake cracks are diverse, not limited to the flow factor itself. This problem has been troubled in the industry for many years and has never been completely solved. Summary of the invention

[0003] The object of the present invention is to provide a method for repairing filter cake of a diaphragm filter press, so as to solve the problem that cracks appear in the filter cake during the process of liquid or gas flowing through the filter cake, causing the liquid or gas to not flow through the filter cake according to the preset process path, resulting in reduced or direct failure of washing and backwashing dehydration effects.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] The filter cake repair method of the diaphragm filter press comprises the following steps:

[0006] S1, the feed liquid enters the filter chamber and is pressurized to form a filter cake;

[0007] S2. When liquid or gas flows through the filter cake, the pressure medium is transported to the diaphragm plate, so that the diaphragm membrane expands and compresses the filter chamber space;

[0008] S3. After the liquid or gas flow is completed, the diaphragm is started to squeeze the filter cake for dehydration.

[0009] Furthermore, in step S2, the pressure of the liquid or gas flowing through the filter cake is greater than the pressure of the diaphragm membrane expansion.

[0010] Furthermore, in step S2, the pressure of the diaphragm membrane expansion is greater than or equal to the feed pressure in step S1.

[0011] Furthermore, in step S2, the pressure of the diaphragm membrane expansion is less than the diaphragm squeezing pressure in step S3.

[0012] The present invention has the following advantages: when liquid or gas flows through the filter cake, the diaphragm plate in the filter plate assembly has a certain tympanic pressure relative to the washing liquid or the back-blowing compressed gas, so that the space inside the filter chamber is always kept in a relatively tight state relative to the volume of the filter cake. Even if cracks are generated in the filter cake during the flow, the pressure of the diaphragm tympanic membrane on the diaphragm plate will prevent the cracks from occurring, or the cracks will be quickly repaired after they are generated. There is no need to worry about the risk of filter cake cracking in the flow process, that is, there is no need to reduce the pressure or flow rate of liquid or gas during the flow, and efficient liquid or gas flow through the filter cake again after the filter press process can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Schematic diagram of filter cake cracks when washing liquid or compressed air flows through.

[0014] Figure 2 Schematic diagram of the repair process of filter cake cracks during diaphragm membrane expansion.

[0015] Figure 3 This is a schematic diagram of the flow of liquid or gas after the filter cake is repaired.

[0016] In the figure, 1-feed plate, 2-diaphragm plate, 3-filter chamber, 4-diaphragm sheet, 5-filter cloth, 6-common feed channel, 7-filter chamber feed channel, 8-filter cake, 9-common discharge channel, 10-discharge outlet in filter chamber. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0020] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0021] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the invented product is usually placed when in use, or the positions or positional relationships commonly understood by those skilled in the art, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0022] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] refer to Figure 1-3 As shown, a schematic diagram of the process of filter cake crack generation and repair. As shown in the schematic diagram of the single-inlet double-chamber feed structure, diaphragm plates 2 are arranged on both sides of the feed plate 1, and a filter chamber 3 is formed between the diaphragm plate 2 and the feed plate 1. A diaphragm sheet 4 is arranged on the diaphragm plate 2, and filter cloth 5 is arranged on the diaphragm sheet and the feed plate 1. The feed liquid enters the filter chamber 3 through the common feed channel 6 and the filter chamber feed channel 7 on the feed plate 1 to form a filter cake 8; the washing liquid or compressed air enters the filter chamber 3 through the common discharge channel 9 on one side to wash or flow through the filter cake, and then enters the common discharge channel on the other side through the filter chamber discharge port 10 on the diaphragm plate 1.

[0024] Existing liquid or gas flow processes such as Figure 1 As shown, after the filter pressing process is completed, when the liquid or gas flows through the filter cake 8 at a high speed, the filter cake is easily split to form cracks, causing the liquid or gas to be discharged from the cracks on the filter cake, resulting in reduced or failed washing and backflushing effects. To solve this problem, this embodiment proposes a method for repairing filter cake of a diaphragm filter press, comprising the following steps:

[0025] S1, the feed liquid enters the filter chamber 3 through the feed channel 7 on the feed plate 1 and is pressurized to form a filter cake 8;

[0026] S2, when liquid or gas flows through the filter cake, the pressure medium is transported to the diaphragm plate 2, so that the tympanic membrane of the diaphragm plate 4 expands and compresses the space of the filter chamber 3;

[0027] S3. After the liquid or gas flow ends, start the diaphragm to squeeze the filter cake to dehydrate it.

[0028] Specifically, when the pressure medium is liquid or gas, it can be transported to the diaphragm plate by opening a valve or a power pump.

[0029] like Figure 2 As shown in FIG3 , when the filter cake is passed through by liquid or gas, the diaphragm plate in the filter plate assembly is subjected to a certain tympanic pressure relative to the washing liquid or the back-blowing compressed gas, that is, by delivering the pressure medium to the diaphragm core plate and the diaphragm sheet, and the diaphragm sheet is a single-channel closed space similar to a balloon, and the diaphragm sheet tympanic membrane is expanded under the pressure-increasing action of the external pressure delivery equipment. As the tympanic membrane pressure of the diaphragm sheet increases, the space in the filter chamber is always kept relatively tight relative to the volume of the filter cake, as shown in FIG3 . Figure 2 As shown in the figure, the tympanic membrane pressure squeezes the filter cake toward the side of the cleaning liquid or back-blowing compressed gas source. Even if cracks are generated in the filter cake during the flow, the tympanic membrane pressure of the diaphragm sheet on the diaphragm plate will prevent the cracks from occurring, or the cracks will be quickly repaired after they occur. The situation where the filter cake is cracked due to excessive liquid or gas flow rate will not occur, causing the liquid or gas to flow directly out of the filter chamber from the cracks without passing through the filter cake will not occur.

[0030] Since the diaphragm is in a tympanic state during the flow of liquid or gas in step 2, the filter cake can achieve self-repair and there is no need to worry about the risk of filter cake cracking. Therefore, there is no need to reduce the pressure of the liquid or gas flowing through during the flow process, and the flow work can be carried out efficiently. Specifically, in step S2, the pressure of the liquid or gas flowing through is greater than the pressure of the expansion of the diaphragm tympanic membrane to ensure the smooth flow of washing liquid or air; the pressure of the expansion of the diaphragm tympanic membrane is greater than or equal to the feed pressure of step S1 to ensure that the diaphragm is in a tympanic state, and the feed pressure is the pressure of the boost to form the filter cake in step S1; the pressure of the expansion of the diaphragm tympanic membrane is less than the diaphragm pressing pressure of step S3 to compress the filter cake for further dehydration.

[0031] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for repairing filter cake of a membrane filter press, characterized in that: The steps include: S1, the feed liquid enters the filter chamber and is pressurized to form a filter cake; S2. When liquid or gas flows through the filter cake, the pressure medium is transported to the diaphragm plate, so that the diaphragm membrane expands and compresses the filter chamber space; S3. After the liquid or gas flow is completed, the diaphragm is started to squeeze the filter cake for dehydration.

2. The method for repairing filter cake of a membrane filter press according to claim 1, characterized in that: In step S2, the pressure of the liquid or gas flowing through is greater than the pressure of the diaphragm membrane expanding.

3. The method for repairing filter cake of a membrane filter press according to claim 2, characterized in that: In step S2, the pressure of the diaphragm membrane expansion is greater than or equal to the feed pressure in step S1.

4. The method for repairing filter cake of a membrane filter press according to claim 2, characterized in that: In step S2, the pressure of the diaphragm membrane expansion is less than the diaphragm squeezing pressure in step S3.

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