small centrifugal pumps

As the "liquid porter" in the industrial field, centrifugal pumps are responsible for more than 70% of the world's fluid transportation tasks. From waterworks to petroleum refining, this rotating machinery's impellers spin thousands of times per minute, creating astonishing industrial efficiencies. This article will disassemble the advantages and disadvantages of centrifugal pumps in plain language, and attach a practical selection parameter table and a guide to avoid pitfalls.   1. Advantages of centrifugal pumps 1. Simple structure: The centrifugal pump has only 6 main components: impeller, pump body, shaft, bearing, seal, coupling, simple structure, few failures, durable, and low manufacturing and later maintenance costs.   2. Uniform flow The flow and pressure of the centrifugal pump are stable, and the operation is smooth, which is very important for use scenarios that require stable flow output.   3. High efficiency The efficiency curve is parabolic: the best efficiency point (BEP) can reach 92%. The efficiency of the centrifugal pump is much higher than other types of pumps, which can reach more than 50%, which can save a lot of energy.   4. Wide range of applications According to the structure: single-stage/multi-stage, single-suction/double-suction According to the medium: corrosion-resistant pump, impurity pump, high-temperature pump According to the installation: vertical, horizontal, pipeline Centrifugal pumps can transport a variety of liquids such as clean water, sewage, seawater, oil and chemicals, and are widely used in municipal engineering, agricultural irrigation, industrial production, ships and other fields.   5. Stable flow and easy adjustment Centrifugal pumps can work stably in a wide flow range, and the flow can be easily adjusted by adjusting the speed, impeller diameter or changing the opening of the pump outlet valve.   2. Disadvantages of centrifugal pumps 1. Before running the centrifugal pump, the pump must be filled with liquid, because if the centrifugal pump runs dry for 5 minutes, the life of the bearing will be reduced by 80%, greatly increasing the failure rate of the centrifugal pump.   2. Centrifugal pumps are sensitive to cavitation, which causes damage to the impeller. Cavitation must be prevented during use. The required NPSHr is 3-5 times higher than that of the positive displacement pump! Anti-cavitation formula: Actual NPSHHa = atmospheric pressure (10.33m) - vaporization pressure - suction line loss - installation height Safety criteria: NPSHa ≥ NPSHr + 0.5m   3. Centrifugal pumps are sensitive to high-viscosity liquids. The higher the viscosity, the lower the efficiency and performance. They are not suitable for high-viscosity fluids and need to choose other types of pumps (such as screw pumps, gear pumps, etc.). 4. The head of a centrifugal pump is greatly affected by the flow rate. When the flow rate deviates from the design, the head will drop significantly.   III. Comparison table of centrifugal pump selection parameters Centrifugal pumps are like "panacea" in the industrial field. Their universal advantages coexist with the defects of working condition sensitivity. Therefore, detailed working condition simulation must be carried out when purchasing. For special medium transportation, the "centrifugal pump +" combination solution can be considered. It is recommended to ask the manufacturer to recommend a suitable centrifugal pump combination solution.