Plunger metering pumpIt is a pump that uses a reciprocating plunger to achieve precise measurement and delivery of liquids. It consists of components such as pump cylinder, transmission mechanism, drive mechanism, and stroke adjustment mechanism. Its working principle is based on the reciprocating motion of the plunger in the pump cylinder. When the plunger moves backward, the volume inside the pump chamber increases, causing the pressure inside the pump chamber to be lower than the inlet pressure. The liquid enters the pump chamber through the inlet valve; When the plunger moves forward, the volume inside the pump chamber decreases and the liquid pressure increases. When the pressure is higher than the outlet pressure, the liquid is discharged from the pump chamber through the outlet valve, thereby achieving precise measurement and delivery of the liquid.
Plunger metering pumpIts core characteristics can be summarized as follows:
1. High precision measurement capability
Wide adjustable flow range: By adjusting the plunger stroke length or driving motor speed, the flow can be precisely adjusted within the range of 0% to 100% to meet different process requirements.
Small measurement error: The sealing design of the plunger and pump chamber (such as soft seal or hard seal) ensures extremely low leakage, and the measurement accuracy can reach within ± 1%, suitable for scenarios with strict requirements for flow stability.
High repeatability: Under the same operating conditions, multiple runs can maintain a highly consistent flow output, ensuring process stability.
2. High pressure resistance and strong corrosion resistance
High pressure conveying capacity: The plunger structure can withstand high pressure (usually up to tens of megapascals), suitable for high-pressure reactor feeding, high-pressure spraying and other scenarios.
Wide material adaptability: Pump heads, plungers, and seals can be made of corrosion-resistant materials such as stainless steel, ceramics, and polytetrafluoroethylene (PTFE), which can transport corrosive liquids such as acids, alkalis, and organic solvents.
3. Compact structure and easy maintenance
Modular design: The pump body, drive device, transmission components, and other modular combinations are easy to install and disassemble, reducing maintenance time.
Less vulnerable parts: The main worn parts are the plunger seal and one-way valve, with a long replacement cycle and simple replacement operation.
Small footprint: Compared to other types of metering pumps such as diaphragm pumps, plunger pumps have a more compact structure and are suitable for situations with limited space.
4. Wide applicability
Viscosity adaptability: It can transport low viscosity (such as water) to high viscosity (such as oil, resin) liquids, but high viscosity liquids require a decrease in flow rate to reduce resistance.
Temperature adaptability: By selecting high-temperature resistant materials (such as ceramic plungers), high-temperature liquids (up to 300 ℃ or above) can be transported.
Media diversity: It can handle suspensions containing solid particles (requiring wear-resistant plungers and hard seals), but the particle size must be smaller than the gap between the plunger and the pump chamber.
5. Flexible driving mode
Motor drive: The standard configuration is an AC motor, which can achieve stepless flow regulation by adjusting the speed through a frequency converter.
Pneumatic drive: suitable for explosion-proof or power-off environments, driven by compressed air to move the plunger.
Manual drive: Small plunger pumps can be equipped with manual operating mechanisms for use in laboratories or temporary feeding scenarios.
6. Safety and reliability
Leakage control: Adopting dual sealing (such as mechanical seal+packing seal) or magnetic drive design, effectively preventing the leakage of toxic and harmful media.
Overload protection: Some models are equipped with overload protection devices (such as torque limiters) to prevent damage to the motor or transmission components.
Long life design: Key components such as plungers and pump heads are made of high-strength materials and processed with precision technology to ensure long-term stable operation.
7、 局限性
Pulsating flow: The reciprocating motion of the plunger causes the flow to output in a pulsating manner, which needs to be relieved by a pulse damper or variable frequency speed regulation.
Noise and vibration: High speed operation may generate significant noise and vibration, and shock absorption measures need to be taken.
High requirements for medium cleanliness: media containing large particles or fibers are prone to clogging one-way valves or wear on plungers, requiring pre-treatment or the use of wear-resistant pumps.