The laboratory piston pump reciprocates by the piston, so that the working volume of the pump chamber changes periodically, and the liquid is sucked and discharged. It consists of pump cylinder, piston, inlet and outlet valve, inlet and outlet pipe, connecting rod and transmission. The power is driven to reciprocate the piston in the pump cylinder. When the piston moves upward, the inlet valve opens, the water enters the pump cylinder, and the water valve on the piston closes, the water in the upper part of the piston rises upward with the piston; when the piston moves downward, the inlet valve closes and the valve on the piston opens. At the same time, the water in the lower chamber of the pump cylinder is pressed into the upper chamber and is raised into the outlet pipe, so that the water is continuously fed and lifted, so that the water is continuously discharged from the outlet pipe. Laboratory piston pumps are divided into single and double acting; single, double and multi-cylinder; horizontal, vertical and inclined; motorized, manual, pedal and animal-powered. The flow rate of the piston pump is Q=0.71-6000 m3/hr, and the discharge pressure P2≤39.2 MPa, in most cases P2≤24.5 MPa.
The laboratory piston pump is a new volumetric structural pump with independent intellectual property rights developed by experts with outstanding contributions, and has obtained many national protections. The pump is a positive displacement self-priming rotary piston pump. The working principle of the laboratory piston pump is as follows: When the power drives the transmission shaft to transmit torque, the drive shaft drives a pair of synchronous gears in the gear box and is fixed on the pump shaft. The two rotors are moved relative to each other to create a vacuum at the suction end of the pump and a load pressure at the discharge end for the purpose of transporting the liquid medium. When the pump rotates continuously, under the relative action of the rotor, the pump shaft discharges six times of fully loaded liquid medium every time it rotates. The steering of the power machine determines the direction of the pump conveying medium, and there is no positive or negative reversal. The flow rate of the pump is proportional to the pump speed within the specified speed range.
The flow rate of the laboratory piston pump is determined by the diameter of the pump cylinder, the stroke of the piston and the number of reciprocations per minute of the piston; the head depends on the characteristics of the piping of the unit, the flow rate of the same piston pump is constant, and the head can vary with the characteristics of the piping of the unit. . That is, the lift is increased, and the flow rate is constant, and only in the high pressure zone, the flow rate is slightly reduced.
The laboratory piston pump is suitable for high pressure and small flow, especially when the flow rate is less than 100 m 3 / hour, and the discharge pressure is greater than 9.8 MPa, which shows its high efficiency and good running performance. It has good suction performance and can pump liquids of different media and different viscosities. Therefore, it is widely used in the petrochemical industry, machinery manufacturing industry, papermaking, food processing, and pharmaceutical production. The low and medium speed piston pumps have low speed and can be manually operated and driven by animal forces. They are suitable for rural water supply and small irrigation.