Views: 41 Author: Site Editor Publish Time: 2021-11-12 Origin: Site
Engineers are generally familiar with operating principles, performance curves and selection criteria for centrifugal pumps, but the training and knowledge around the operating principles of reciprocating pumps is not as common.
A centrifugal pump consists of an impeller rotating within a casing. Liquid directed into the center of the rotating impeller is picked up by the impeller vanes, accelerated to a higher velocity by the rotation of the impeller, and discharged by centrifugal force into the casing and out the discharge.
When the liquid in the impeller is forced away from the center of the impeller, a low-pressure zone is created at the impeller eye and consequently more liquid flows into the pump. Therefore, a steady flow through the impeller is produced unless something happens to disrupt the low-pressure zone at the inlet or disrupt the flow to the center of the impeller, unless the flow at the discharge is restricted by a pressure greater than the pressure head developed by the rotating impeller.
The reciprocating pump does not generate head. Instead, the pump converts rotating motion and torque into linear motion and force, generating variable flow at the discharge connection.
The system’s resistance to flow generates head. Hence, the pump will draw upon available power and energy until it overcomes all flow resistances downstream. If excessive flow restrictions exist, the pump can be over pressurized, and the driver may stall or the weakest link in the system can fail. Therefore, it is imperative that a safety relief valve is installed in the system.
Centrifugal pump engineers are familiar with selecting pumps from a performance range using performance curves that map the operating range. A reciprocating pump’s flow is determined by the volume of its cylinders and the rate at which the piston can move fluid through into the system. The pump is a fixed volume machine.
Unlike centrifugal pumps, reciprocating pumps have a stronger interaction with the system within which they sit. This is due to the pressure pulsations they generate.
Reciprocating pumps run at a much lower speed than centrifugal pumps. By increasing the speed, there can be compromises to the packing and sealing life of the machine. Balancing speed and plunger size is the key to reliability plunger and sealing life.
Reciprocating pumps can be more efficient than centrifugal pumps, if they are used in the correct application. Reciprocating machines are generally applied on low-flow and high-head service.
Centrifugal pumps can have efficiencies as low as 20 percent on low-flow and high-head service. A reciprocating machine, on the other hand, can have efficiencies more than 90 percent on the same service. Efficiency of a pump is directly related to energy consumption. It could be expected that the energy costs of a centrifugal pump are typically 1.40 times to 1.90 times that of a reciprocating pump.
A pump is a machine that converts mechanical energy into liquid energy and is used to pressurize and transport liquid. The high-pressure pumps we provide are reciprocating pumps in the positive displacement pump category, and piston pumps in the reciprocating pump category. The pump efficiency of our structure is the highest among all pumps, so it saves energy and consumes less electricity. In terms of operating costs, our pumps have huge advantages. In many cases, one pump investment can be saved a year.
The product that suits you is the best; but a decision can be made by examining the needs pertaining to the pumping system, initial investment, operating cost, maintenance, and personnel’s knowledge about pumps.