How to select a diaphragm pump for a plate and frame filter press

The plate and frame filter press manufacturer believes that first of all, the filter press is powered by the flow of the pump. The selection of the pump should be based on the processing capacity and processing cycle of the equipment as a reference.

Secondly, based on the volume of the filter chamber of the plate and frame filter press, the moisture content of the sludge after dewatering, and the concentration of the sludge before entering the plate and frame, calculate the amount of sludge required for each dewatering operation of the plate and frame. Then, determine a reasonable sludge feeding time, such as 2 to 3 hours. Calculate the flow rate.

Then, the material of the diaphragm pump

If it is ordinary biological sludge, choosing ordinary cast iron polypropylene material is more economical. For other special sludges, the material of the diaphragm pump should be selected based on the specific sludge composition, such as stainless steel 304,316, aluminum alloy, and fluorine-lined.

Matters needing attention in the design:

A pressure reducing valve with pressure indication and a small ball valve are installed on the intake pipe to facilitate the observation and adjustment of the flow and pressure of the diaphragm pump.

2. When starting the dehydration process, the air pressure should be controlled at 2-3bar. Once the water output rate significantly decreases, increasing the air pressure will yield better dehydration results.

3. The quality of the conditioning effect of sludge plays a decisive role.

Second, the disadvantages of using diaphragm pumps:

1. The pressure cannot be increased and is restricted by the gas source pressure. 6bar is the upper limit.

2. Noise and pipeline vibration are particularly obvious when the air volume is large.

3. Compared with screw pumps, the diaphragm has a shorter lifespan and is prone to damage.

4. As the flow rate of diaphragm pumps is usually not very large, they are mostly applied in small systems.

Third, the advantages of using diaphragm pumps:

The investment is low. For screw pumps, a flow-regulating device, a frequency conversion or pressure regulating valve, and a matching pressure sensor are also required.

2. It is reliable and simple to operate, and can automatically balance the flow rate as the filtration resistance increases.

3. It occupies a small area and is very easy to install.