Is the "heart" of the plate and frame filter press a diaphragm pump good? Or screw pump?

Is the "heart" of the plate and frame filter press a diaphragm pump good? Or screw pump? For the filter press, the pump is just like the heart of human body. It is very important for the filter press to choose a good pump. The advantages and disadvantages of the two pumps are briefly listed below for users' reference.

Selection basis of pump
I. Processing capacity and cycle the plate-frame filter press relies on the pump flow as power, and the pump selection should be based on the processing capacity and processing cycle of the equipment as reference.
2. Flow rate according to the volume of the filter chamber of the plate and frame filter press, the moisture content of the dehydrated mud, and the concentration of the sludge before entering the plate and frame, the amount of mud needed by the plate and frame to complete the dehydration operation each time is calculated. Then, determine the reasonable time of entering the mud, for example, 2-3 hours. Calculate the traffic.
III. Characteristics of the object to be processed:
For example, ordinary biological sludge is made of ordinary cast iron polypropylene, which is relatively economical. For other special sludge, pump materials such as stainless steel 304,316, aluminum alloy and fluorine lining should be selected according to specific sludge composition.

Plate and frame filter press diaphragm pump and screw pump disadvantages contrast:
Disadvantages of using diaphragm pump:
1. The pressure can't be increased. Limited by the air source pressure, 6 bar will reach the upper limit;
2. Noise and pipeline vibration are especially obvious in the air volume;
3. Compared with the screw pump, the membrane has a shorter life and is easy to be damaged;
4. Because the flow rate of diaphragm pump is usually not too large, most of them are used in small systems;

Advantages of adopting diaphragm pump:
1. If the investment is low, the screw pump needs a device which can adjust the flow, frequency conversion or pressure mediation valve, and also needs a matched pressure sensor;
2. The work is reliable and simple, and the flow can be automatically balanced with the increase of filtering resistance;
3. It covers a small area and is easy to install.

Advantages of adopting screw pump:
(1) the range of pressure and flow is wide. The pressure is 33-3332N/cm2. the flow rate can reach 18600cm3/min;
(2) the variety and viscosity range of the liquid transported are wide;
(3) because the inertial force of the rotary parts in the pump is relatively low, a very high rotating speed can be used;
(4) good suction performance and self-suction capacity;
(5) The flow is uniform and continuous, with small vibration and low noise;
(6) compared with other rotary pumps, they are less sensitive to the incoming gas and dirt;
(7) solid structure, easy to install and maintain.

Its disadvantage is that the requirements of screw processing and assembly are relatively high; the performance of pump is relatively sensitive to the change of liquid viscosity.
The screw pump of plate and frame filter press is electric, but if the screw pump of filter press exceeds the rated pressure, the internal parts of the pump will be damaged. Pneumatic diaphragm pump can avoid this problem. If the pressure is too high, the pump will stop automatically. Both have their own advantages and disadvantages.