Guidelines for Material Selection of Diaphragm Filter Plates

Here is a guide to the selection of diaphragm filter plate materials:

Consideration Factors

Chemical Resistance: The material of the diaphragm filter plate should have good chemical resistance to prevent corrosion and degradation when in contact with various chemical substances in the filtration process. For example, in the chemical industry, when filtering acidic or alkaline solutions, materials with high acid and alkali resistance are required.

Mechanical Strength: It needs to have sufficient mechanical strength to withstand the pressure during the filtration process and the force generated by the diaphragm's compression. This ensures that the filter plate does not deform or break under high pressure, thereby ensuring the normal operation of the equipment.

Wear Resistance: Since the filter plate is in contact with solid particles in the slurry during the filtration process, it is necessary to have good wear resistance to extend the service life of the filter plate. In applications where the slurry contains abrasive particles, such as in the mining industry, wear - resistant materials are particularly important.

Temperature Resistance: The material should be able to withstand the temperature of the slurry during the filtration process. In some high - temperature processes, such as in the thermal power industry, filter plate materials with high - temperature resistance are required to ensure the stability and performance of the filter plate.

Sealing Performance: The material of the diaphragm filter plate should have good sealing performance to prevent leakage of the slurry during the filtration process. This requires that the material has good elasticity and compressibility to ensure a tight seal between the filter plates.

Common Materials and Their Characteristics

Rubber - Coated Diaphragm Filter Plate:

Advantages: Good chemical resistance, excellent elasticity, and sealing performance. It can adapt to a certain degree of deformation and is suitable for filtering materials with complex chemical components.

Disadvantages: The mechanical strength is relatively low, and it is not suitable for high - pressure filtration. The temperature resistance is limited, generally suitable for temperatures below 80°C.

Polypropylene Diaphragm Filter Plate:

Advantages: High chemical resistance, good wear resistance, and relatively high mechanical strength. It can withstand a certain degree of pressure and is suitable for a variety of chemical and industrial applications. The temperature resistance is better than that of rubber - coated filter plates, generally up to 100 - 120°C.

Disadvantages: The elasticity is slightly worse than that of rubber - coated filter plates, and the sealing performance needs to be improved through other sealing structures.

Composite Material Diaphragm Filter Plate:

Advantages: Combines the advantages of different materials, such as high mechanical strength, good chemical resistance, and excellent sealing performance. It can be designed and manufactured according to specific application requirements to achieve better overall performance.

Disadvantages: The manufacturing process is relatively complex, and the cost is relatively high.

Selection Recommendations

For applications with high chemical resistance requirements and relatively low pressure, such as in the pharmaceutical and food industries, rubber - coated diaphragm filter plates can be considered. Their good chemical resistance and sealing performance can meet the requirements of these industries for product quality.

In chemical and industrial applications with medium - high pressure and general chemical resistance requirements, polypropylene diaphragm filter plates are a good choice. Their high mechanical strength and wear resistance can adapt to the harsh working conditions of these industries.

For applications with high - end requirements, such as in the mining industry where there are high - pressure, abrasive materials, and complex chemical environments, composite material diaphragm filter plates are recommended. Although the cost is high, their excellent comprehensive performance can ensure the long - term stable operation of the equipment.