How to choose the right type of pump
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How to correctly select the pump type: The type of pump should be chosen appropriately based on factors such as the process parameters of the installation, the physical and chemical properties of the medium to be transported, the operating cycle, and the structural characteristics of the pump. Centrifugal pumps have advantages such as a simple structure, pulse-free fluid delivery, and easy flow regulation; therefore, except in the following situations, centrifugal pumps should be preferred wherever possible: 1. When metering is required, a metering pump should be used. 2. When a very high head is required, the flow rate is low, and no suitable centrifugal pump with a low flow rate but high head is available, a reciprocating pump can be used ； Vortex pumps can also be chosen when the requirements for cavitation are not high. 3. When the head is very low and the flow rate is high, axial flow pumps and mixed-flow pumps can be selected. 4. When the medium viscosity is high (greater than 650–1000 mm²/s), rotary pumps or reciprocating pumps can be considered; in cases of particularly high viscosity, specially designed high-viscosity rotary pumps and high-viscosity reciprocating pumps can be used. 5. When the gas content in the medium is >5%, the flow rate is low, and the viscosity is less than 37.4 mm²/s, a vortex pump can be used. If pulsation in the flow rate is allowed, a reciprocating pump can be used. 6. In applications where starting is frequent or pumping is difficult, pumps with self-priming capabilities should be used, such as self-priming centrifugal pumps, self-priming vortex pumps, and positive displacement pumps.
In cases where the head is relatively high but the flow rate is low, high-speed pumps can be an option; however, they are more complex and difficult to maintain. If backflow is possible, it is better to use a centrifugal pump.
Centrifugal pumps are of course widely used, but in situations where monomers need to be transported without any shear forces, pneumatic diaphragm pumps are a better choice. For example, it is used for transporting orange juice in granule form and natural rubber. In situations where sludge is compressed using a filter press, the pressure changes constantly; it is better to use a pneumatic diaphragm pump, as it can achieve automatic pressure balance and shut down automatically, while starting up again when there is a pressure difference. The disadvantages of pneumatic diaphragm pumps are pulsation, high noise, and limited delivery pressure. In applications with high viscosity, gear pumps or screw pumps are a better choice, as they can handle high viscosities and high pressures. The disadvantage is high shear force, and it performs poorly when transporting materials containing hard particles.