Filter Plate

Filter plate

Filter plate is a key device in water treatment process, which plays a dual role in the filter tank, supporting the filtration of filter media layer and backwashing water (gas). The quality of filter plate (especially the flatness and precision of filter plate) is directly related to the quality and quantity of filtered water and long-term benefits of operation of water plants and sewage treatment plants. The traditional filter tank water distribution system has large resistance during filtration and backwashing, uneven water distribution, many dead water areas, easy compaction and mud accumulation of filter media, and loose support layer due to local flushing intensity, resulting in sand leakage and other adverse consequences.

Chinese name: Filter plate Foreign name: Filter plate Application: Water treatment process

Construction technology: prefabricated filter plate, integral casting

Function: Carrying filter layer filtration and backwashing water (gas)

Detection method: Level meter

Purpose

1. Catalyst filtration and separation;

Filter plate

Filter plate

2. Petrochemical high-temperature gas filtration, petrochemical plant boiling bed tail gas filtration, catalytic cracking oil slurry filtration;

3. Purification of high-temperature flue gas in the metallurgical industry;

4. Filtration of other high-temperature gases and liquids;

5. Filtration of various high-temperature, corrosive liquids and catalysts in the petrochemical industry;

6. Filtration and purification of various polymer melts in the chemical fiber film industry;

7. Filtration and separation of various catalysts in the pharmaceutical industry;

8. Used for gas distribution, liquidized bed orifice plate materials;

9. Used for high-pressure backwashing oil filters, etc.;

10. Used to filter edible oil, beverages and various edible slurries;

11. Used for purifying and filtering production sewage

Installation requirements

The horizontal installation accuracy of the filter plate is relatively high. Its important basis is the leveling of the entire pool involving the filter beam and the positioning accuracy of the stainless steel parts used for pre-embedded riveting filter plates. Therefore, the leveling of the filter beam requires a horizontal line. It is necessary to have a high-standard metal mold and skilled manufacturing technology to ensure the flatness of the filter beam. After the plane is leveled, the filter plate can be installed.

1. Carry out construction according to the requirements of the design drawings. The horizontal error of a single pool plate surface is greater than ± 2mm, and the elevation error of each filter tank is not greater than ± 5mm;

2. The filter plate joints are required to be airtight and watertight and able to withstand the pressure of flushing;

3. Before laying the filter plate, use a level to check that the elevation error of the supporting beam surface is less than ± 2mm;

4. The filter plate joints are embedded and filled with 903 polymer cement mortar. The embrittlement is cured in a humid environment for three days and put into use after seven days;

5. During construction, it should be noted that the mortar cannot leak into the pool or seal the filter head. After installation, the mortar on the filter plate surface must be cleaned.

Construction technology

Prefabricated filter plate construction technology

Introduction:

Prefabricated filter plates should use horizontal steel molds, produce one piece at a time, and the demoulding time is 24h (no less than 16h in high temperature in summer, that is, demoulding three times every two days). In addition, there are vertical molds that can produce five pieces each time. However, it is difficult to remove the gas in the mold, and the filter plate produced has many bubbles. In addition, due to gravity, the concrete is uneven and the strength is very low when the insert vibrator is vibrated and compacted. The position of the steel bars is difficult to fix, and many steel bars are exposed. The density of the filter plate edge is even lower, and there are many burrs, defects, and corners.

Construction plan:

(1) Measurement and layout – installation of filter beams – leveling – hoisting filter plates – installation and leveling – special sealing and sealing mud filling – installation of filter heads – installation of pressure plates – draining – pressure testing and drainage – cleaning the site.

(2) Construction methods of the main processes. According to the construction drawings, the construction workers will conduct actual measurements and verification of the filter tank. If the drawings are found to be inconsistent with the site, they will immediately contact the client and the design party to resolve the issue. After verification, the layout measurement will be carried out.

(3) Configuration of instruments and meters. Levels, calipers, rulers and other measuring instruments should be configured according to the needs of the project, and the supervision unit should be contacted to prepare for the line inspection.

Advantages and Disadvantages:

(1) Advantages: Low cost, about 1000-1500 yuan/m2; flexible construction, can be constructed on site or prefabricated in the factory; low requirements for construction machinery, only one small concrete mixing tank is required.

(2) Disadvantages: The process of assembling prefabricated reinforced concrete panels and then treating the joints. The problems of this process are that the joints are prone to air leakage, the joint height difference is large, and the flatness of the bottom of the board is difficult to control during assembly.

Integral cast filter plate

Introduction:

The overall cast-in-place filter plate has the characteristics of integral casting and adjustable filter plates. The bottom template of the integral cast concrete filter plate is a corrugated plate made of special high-strength food-grade plastic in one go to ensure the strength of the template during casting; a round hole with a neck sleeve is opened at the convex part to fix the embedded seat of the long-handled filter head. The adjustable filter head consists of an embedded seat, a filter rod, and a filter cap. There is a latch on the embedded seat to facilitate fixing on the template. The filter rod is provided with an adjustment thread, which can be adjusted up and down. The adjustment flap is provided to cooperate with the anti-slip strip of the adjustment flap in the embedded seat to control the adjustment accuracy of the filter rod. The integral cast-in-place filter plate has an industry specification: “CECSl78-2005 Technical Specifications for Integrally Cast Filter Plates with Adjustable Filter Heads for Air-Water Flushing Filters”, and the construction technology refers to this specification.

Advantages and Disadvantages:

(1) Advantages: There is no joint between the plates, and no sealing and waterproofing measures are required for the joints; the reinforced concrete filter plate is continuously cast on site to form a whole, and is connected to the filter tank wall as a whole, and is equipped with an adjustable filter head. This improves the uniformity and reliability of the water distribution system of the air-water recoil filter.

(2) Disadvantages: High cost, 50% to 100% higher than prefabrication; high requirements for construction machinery, which must meet the requirements of pumping commercial concrete and casting on a hanger-type working platform; ABS prefabricated modules provided by professional manufacturers are required.

Stainless steel filter plate

Structure

Filter plate

Filter plate

The stainless steel filter plate water distribution system consists of the bottom bearing structure, stainless steel filter plate, assembled special water distribution filter head and other main parts.

Bearing structure: The bottom bearing structure of the filter plate consists of vertical stainless steel pillars and horizontal stainless steel bearing beams connecting the pool bottom and pool wall. The stainless steel pillars and bearing beams are all steel. In the new filter tank project, the stainless steel bearing structure can be welded with the embedded parts embedded in the pool bottom and pool wall or connected and fixed with the embedded bolts; in the original filter tank renovation project, the fixing bolts can be placed on the pool bottom and pool wall by planting reinforcement, and then fixed with the stainless steel support column and bearing beam, so that the stainless steel filter plate bearing structure is connected to the filter tank civil structure: For the filter tank with existing concrete filter beam structure, the original concrete support beam can also be used for installation.

Stainless steel filter plate: The filter plate is made of high-quality stainless steel plate. According to the process requirements, the filter plate is provided with holes and slots for installing the filter head embedded parts on both sides. The upper surface of the filter plate is mechanically molded in one step, and multiple convex and concave reinforcement strips are distributed corresponding to the installation position of the filter head; multiple reinforcement ribs are arranged in the vertical direction of the lower part of the filter plate and the upper reinforcement ribs, which play the role of fixing the embedded parts of the filter head and strengthening the bottom; the embedded parts of the filter head with special structure are provided with slots above and below, and after passing through the upper and lower fixing holes of the filter plate, they are rotated at a certain angle and then locked and fixed.

Water distribution filter head: The filter head is installed on the filter plate through a sleeve, a slot, and a sealing ring. The corresponding opening ratio is set according to the different flushing methods of the filter tank, and different types of filter heads or filter heads of different densities are configured. The single water flushing filter tank adopts a short-handled filter head, and the filter rod is flush with the bottom surface of the filter plate; the air-water backwashing filter tank adopts a long-handled filter head, and the filter rod extends a certain length from the bottom of the filter plate. The filter rod is provided with an air intake slot and air intake and exhaust holes to meet the requirements of forming a stable air cushion layer, uniform air intake, and exhaust when flushing the air-water backwashing filter tank.

Advantages

The high-precision stainless steel filter plate is machined and formed by high-quality stainless steel plates. After the water distribution system is installed, the two-way pressure bearing strength is high; the special filter head assembly made of high-strength engineering plastics has a scientific opening ratio; the filter head is fixed with reinforced threads in the structure, and the rubber gasket is sealed, the connection is firm and will never fall off; there is no dead water area between the filter plate and the filter head, no mud accumulation, no rust, and aging resistance; safe and hygienic, durable use, and no maintenance. It can be flexibly customized according to the user’s filter tank type, changing the previous filter plate that can only adopt a nearly square block design mode due to process limitations, and realizing the whole-piece manufacturing and installation of the filter plate between the two filter beams in the filter tank. There is no joint seam at the bottom of the filter plate without support, ensuring the integrity of the filter plate in the filter tank and the ideal goal of permanent stable, safe and efficient operation.

Installation inspection

Use a level to check the level, add a plug to drain the water to check the tightness. The success or failure of the filter plate production and installation is directly related to the success or failure of the gas-water backwashing process. Compared with the traditional single water flushing process, the air-water backwashing process adds air backwashing, which requires that the horizontal error of the filter plate surface of a single pool is no more than ±2mm, and the elevation error of each filter pool is no more than ±5mm. Only in this way can uneven backwashing be avoided to cause sludge agglomeration and affect water quality and treatment effect.

Details