Cause analysis of sealing failure of diaphragm filter press filter plate

The reasons for the sealing failure of the filter plates in a diaphragm filter press can be analyzed from aspects such as filter plate deformation, damage to sealing components, improper installation, and issues with the filtration medium. Here is a detailed analysis:

Filter Plate Deformation

Over - pressure Operation: If the pressure applied during the filtration process exceeds the rated pressure of the filter plate, it may cause the filter plate to deform. This is because excessive pressure exerts a large force on the filter plate, exceeding its load - bearing capacity. For example, in some industrial production processes, if the pressure control system malfunctions and the pressure continuously rises, the filter plate is likely to deform, resulting in a poor seal between the filter plates and leakage.

Material Quality Issues: The quality of the filter plate material also affects its resistance to deformation. If the material has low strength or poor rigidity, it is more prone to deformation under normal operating pressure. For instance, if the filter plate is made of low - quality plastic or the proportion of reinforcing materials in the composite material is insufficient, its mechanical properties will be affected, making it more likely to deform during use.

Damage to Sealing Components

Wear and Tear of Sealing Rings: The sealing ring is a key component to ensure the sealing performance of the filter plate. During the operation of the filter press, the sealing ring is continuously subjected to mechanical friction and chemical corrosion. As time passes, the sealing ring will gradually wear out. If the wear is severe, the sealing ring will no longer be able to fit tightly with the filter plate, resulting in a sealing failure. For example, in a filtration system that processes abrasive materials, the wear of the sealing ring will be more obvious.

Chemical Corrosion: If the filtration medium contains corrosive substances, it may cause chemical corrosion to the sealing ring. This will change the material properties of the sealing ring, making it brittle, cracked, or swollen, thereby losing its sealing function. For example, when filtering acidic or alkaline solutions, if the sealing ring material is not resistant to corrosion, it will be corroded by the solution, affecting the sealing performance.

Improper Installation

Incorrect Assembly: During the installation of the filter plate, if the installation process is not carried out in strict accordance with the operating instructions, it is easy to cause uneven force on the filter plate or incorrect installation of the sealing ring, resulting in sealing failure. For example, if the filter plate is not installed in place, or the sealing ring is not evenly placed in the groove of the filter plate, there will be gaps during operation, leading to leakage.

Lack of Regular Maintenance: Failure to perform regular maintenance on the filter press and check the installation status of the filter plates and sealing components can also lead to sealing failures. Over time, the bolts connecting the filter plates may loosen, causing the filter plates to shift and the sealing performance to decline.

Issues with the Filtration Medium

High Solid Content: If the solid content in the filtration medium is too high, the resistance during filtration will increase, resulting in uneven force on the filter plate. This uneven force can cause the filter plate to deform slightly, affecting the sealing effect. In addition, the high - content solid particles may also scratch the surface of the filter plate and the sealing ring, leading to sealing failure.

Viscosity Changes: Changes in the viscosity of the filtration medium can also affect the filtration process and sealing performance. When the viscosity is too high, the pressure required for filtration increases, which may cause the filter plate to be under excessive pressure. On the other hand, if the viscosity is too low, the liquid may leak through the sealing gap more easily, resulting in a decrease in sealing performance.