Basic Knowledge of (Water Supply and Drainage) Pumps

(Basic Knowledge of (Water Supply and Drainage) Pumps)  
Water Pump equipment accounts for more than 15% of the total investment in mechanical equipment, and in terms of energy consumption, they are also major energy-consuming devices, so they are key power equipment.  

1. Definition of a Pump:  
A mechanical device that converts mechanical energy into liquid energy and is used to transport liquids.  

2. Classification of Water Pumps  
Due to differences in the volume of water to be transported, distance, lift, and the medium, wastewater treatment plants use various forms of Pump equipment, which can mainly be divided into: impeller Pumps, positive displacement Pumps, and other types of Pumps, such as screw Pumps.  

2.1 Impeller Pumps  
Impeller-type pumps are a large category of Water Pumps. They rely on the high-speed rotation of the impeller to complete the energy conversion. Differences in the impeller blades cause different forces on the water flow, and the direction of water leaving the impeller varies. Based on the water flow direction from the impeller, impeller-type pumps can be divided into radial flow, axial flow, and mixed flow. When liquid particles flow through the impeller, they mainly experience centrifugal force, axial lift, or a combination of both forces, respectively. Correspondingly, these are called centrifugal pumps, axial-flow pumps, and mixed-flow pumps.  

In wastewater treatment systems, the primary pumps used are impeller pumps. Among them, centrifugal pumps are the most common due to advantages like high efficiency, quick start-up, stable operation, reliable performance, and easy adjustment. Centrifugal pumps must be filled with water in both the pump casing and suction pipe before starting.  

Pump Performance Parameters  
In China, pump models generally consist of two parts: numbers and Pinyin letters. Numbers indicate the pump's inlet diameter, outlet diameter, flow, lift, etc., while Pinyin letters represent the pump's type, structure, and so on. These model parameters are displayed on the equipment nameplate. Since most pump models, types, and structures are determined by individual manufacturers, the representation methods may vary even for pumps of the same type.  

Common pump performance typically includes parameters like flow, lift, power, speed, efficiency, suction diameter, and impeller diameter. During equipment selection, the focus is mainly on the pump's flow, lift, power, and allowable suction vacuum height.