10 Frequently Asked Questions about Plate and Frame Filter Press

 

Q1: What should I do if there are wear grooves on the edge of the filter plate?

After the filter plate is used for a period of time, due to the influence of particulate matter and other factors, grooves will appear on the edges of the filter plate. If these small damages are not paid enough attention to, it will easily lead to the filter cake not being formed properly, thus causing grooves. Expansion makes it difficult to form the filter cake.
Generally speaking, the debris on the grooves should be cleaned first to make the grooves of the filter plate smooth and tidy; then, according to the instructions for using the repair agent, apply the repair agent evenly on the grooves of the filter plate; finally, put the prepared The leather strip is put on and squeezed to quickly bond the two. It is worth mentioning that the flatness of the groove must be ensured during the bonding process. The filter plate and leather strips are firmly bonded together to complete the repair of the filter plate.

Q2:What is the reason for the spray material between the filter plates?

Reason 1: Caused by excessive feed pressure. Many users do not install a pressure gauge on the feed pipeline, causing the feed pressure to be out of control and eventually causing material spraying.
Reason 2: The pressing force to compress the filter plate is not enough. When the feed pressure increases, the force between the filter plates will spread the filter plates and cause material spraying.
Reason 3: There are filter cakes and other debris attached to the sealing surface of the filter plate. There is always a large gap after the filter plate is pressed. The sealing surface should be cleaned after removing the filter cake.
Reason 4: There is a through-groove on the sealing surface of the filter plate or the filter plate itself is damaged.

Q3: How to solve the problem of water seepage and material leakage between the filter plates?

Generally, there are four main reasons why this happens:
It may be that the feed pressure is too high, causing the filtration rate of the feed liquid to be too high; or the hydraulic pressure of the hydraulic system is low; there are holes in the filter cloth pleats and filter cloth, or there are lumps on the sealing surface; in the end, I feel that it is still possible. There is a possibility that the filter cloth is not cleaned according to the regulations, or the cleaning effect is not good and does not meet the requirements.
When this failure occurs, first the corresponding pressing pressure should be increased. Next, if there is a problem with the filter cloth or sealing surface, the filter cloth should be replaced in time, the debris on the sealing surface should be cleaned, and the filter cloth should be cleaned on time; finally Is to reduce the feed pressure to normal value.

Q4：What is the reason for the low movement speed of the filter plate? How to solve?

The guide rod is easily contaminated by oil stains, which will slow down the movement speed of the filter plate, and even cause the filter plate to fail to run along the track and fall off. When slow movement occurs, the dirt on the guide rod should be cleaned, kept clean, and lubricant should be evenly applied on its surface to make the guide rod move more smoothly.

Q5:What should I do if the filter plate cannot be opened?

After the filter press is blown, the filter plate often does not open or stops intermittently during the loosening operation.
At this time, the filter plate must first be loosened to release the pressure to meet the pressure standard requirements. Once the pressure is not completely relieved, problems will occur in the filter plate loosening action due to the operation lockout. In addition, if the system loses too much during long-term operation and the hydraulic oil is not replenished in time, the system will not be supplied with enough oil, resulting in poor continuity of the hydraulic cylinder's work and intermittent phenomena.

Q6:Why does the filter cake have uneven shape or thickness?

The reason for this phenomenon may first be insufficient material supply or too low material supply concentration. Of course, it may also be that the components are blocked during operation.
Generally speaking, under the conditions of ensuring the normal operation and use of the plate and frame, the feed amount of the filtrate should be appropriately increased to ensure sufficient feed; if necessary, it is considered possible to consider upgrading the existing process to improve the quality of the materials. quality to ensure that the concentration of the material is within a reasonable range; at the same time, the drainage holes of the material in the plate and frame can also be cleaned regularly to ensure the smooth flow of the drainage pipeline; finally, during the forming process of the filter plate, the compression pressure is increased to ensure The filter cake is well formed.

Q7:What should I do if the filter plate movements are out of sync during the closing process of the filter press?

When the filter press is working, there is a latching and linkage relationship between its internal mechanical structures. Once the filter plate does not move after the closing operation, it is necessary to promptly check whether the unloading trolley is in the initial position.
If the unloading trolley does not move and the position does not change, it is necessary to further check whether the initial position detection device is operating normally. If the detection device fails, it must be repaired in time.

Q8:What are the causes and countermeasures for noise in the hydraulic system of filter presses?

During the compression process of the filter press, the hydraulic system makes abnormal noise, which is mainly caused by loose fasteners in the system or excessive viscosity of the hydraulic oil.
System fasteners should be inspected and tightened if loose. If the viscosity of the hydraulic oil is too high, just reduce the viscosity.

Q9:How to judge whether the sludge is pressed dry using a plate and frame filter press?

Theoretically, it is impossible to press dry the sludge in the plate and frame filter press, and it can only be understood as the end of the feeding process. It can be judged from the following two points:
The feed pressure has reached the upper limit of the set feed pressure; the liquid discharge volume of the filter plate has been significantly reduced. If you want to further reduce the moisture content of the filter cake, you can adopt the following two methods: increase the feed pressure (provided that the hydraulic cylinder pressure is sufficient); use compressed air to blow away the moisture.

Q10:What is the reason for the low closing pressure of the filter plate?

During the actual operation of the plate and frame filter press, if the liquid level in the hydraulic station tank is low, it may be caused by leakage points in the hydraulic pipeline, which will cause pressure loss in the hydraulic station;
There is a large position error in the installation of the filter plate limit detection device, which causes the filter plate displacement control system to lift up and control the hydraulic pump to stop working prematurely; the filter plate closing pressure setting is too small, which will also cause the filter plate compaction to be completed. low pressure.