As for so many products with the names of pumps on the market, what exactly do we need? And how to divide the types of these pumps, let me introduce them to you (Changsha kuosi)

1： According to the number of impellers, the pump is divided into:

1. Single stage pump - only one impeller

2. Multistage pump - multiple impellers, one impeller is the first stage. The higher the series, the higher the lift

2、 The performance curve and characteristics of centrifugal pump 1. Performance curve Q-H performance curve is Zui basic. It is useful for pump selection and use. 2. Features: advantages: 1. Large flow range. Stable flow and pressure. 2. High speed. It can be connected with motor and steam turbine. The transmission mechanism is compact. 3. Reliable operation, easy adjustment and maintenance, easy automation and remote operation. 4, Disadvantages: 1. In general, the tank pump or vacuum pump is needed to pump air before starting, but the self-priming pump is not used. 2. When the viscosity increases, Q, h, suction head and efficiency will be significantly reduced. 3. In the case of small flow and high head, it is trapped

3、 The suction height and cavitation of a centrifugal pump can only raise the water by 10.3 meters at one atmospheric pressure. If the pump is installed too high from the liquid level, which exceeds the allowable suction vacuum height minus the suction pipeline loss, then the central pressure of the pump impeller is reduced to equal to the saturated vapor pressure at the liquid temperature at that time, and the liquid begins to boil and vaporize, forming vapor bubbles in the liquid flow, The bubble is full of steam and the vapor separated from the liquid. When the bubble is brought into the high pressure area of the impeller by the liquid flow, the steam in the bubble suddenly condenses and causes the bubble to break. Because the bubble breaks very quickly, the surrounding liquid rushes to the original space occupied by the bubble at a very high speed, which produces a strong impact, i.e. water hammer, The higher the vacuum height, the better the cavitation performance. If the same suction height of the pump, the higher the speed of the pump, the better the cavitation performance, By increasing the number of revolutions, the number of stages, volume and weight of the pump can be reduced

5、 General single-stage centrifugal pump has many kinds and wide application. It is mainly used to transport water below 80 ~ 100 ℃ and liquid without chemical corrosion

1. Single stage and single suction: A, single stage cantilever - General Agricultural machinery factory can produce large quantities. B, single-stage direct coupling - C, single-stage suspension - large flow (more than 80 km / h), lift less than 15 m

2. Single stage double suction urban water supply, power station, water conservancy project, agricultural tank. Q: 90-28600 M / h, 10-140 m water column

6、 General multistage centrifugation

1. Sectional multi-stage water supply for mines, factories and cities. Q: 5-720 M / h, head: 100-650 m water column. High head, easy to manufacture, but difficult to assemble and disassemble

2. Middle opening multi-stage is used for urban water supply, mine drainage and oil pipeline with large flow and high head. Q: 450-1500 M / h, lift of 100-500 m water column, and discharge pressure of 180 kg / cm 2

7、 Centrifugal well pump and hanging pump

1. Well city water supply and drainage, industrial and mining enterprises water supply and drainage, agricultural tank, etc

2. Pump the well water

8、 Centrifugal boiler feed and condensate pumps

Low pressure: 0-50 kg / cm 2 medium pressure: 50-100 kg / cm 2 high pressure: 100 kg / cm 2 low pressure pump, the temperature of the liquid delivered does not exceed 1100c 2, condensation is used to transport condensate in condenser of power plant

9、 Centrifugal oil pump cold pump - below 2000c hot oil pump - above 2000c

1. General centrifugal oil pump Q: 6.25-500m3/h head: 60-603m water column

2. Cylinder type high temperature and pressure Q: 10-100m 3 / h head: 40-1440 m water column

3. Centrifugal pipe is suitable for outdoor without elbow, commonly used in China Q; 6.25-360 m3 / h head: 24-150 m water column

10、 Pump turbine unit is commonly used in nitrogenous fertilizer plant. Chapter 4 axial flow, mixed flow and vortex pump

1、 Axial flow characteristics: A, Q-H are very steep, when q = 0, Zui large head is about 1.5-2 times of Zui rate. B, the smaller the flow rate, the greater the power required. Therefore, when starting, the valve on the discharge pipeline should not be closed, otherwise the motor overload. C. The effective range is narrow, and the discharge flow adjustment is made into adjustable blades, It is used for agricultural tank, urban drainage, circulating water of thermal power station which needs a lot of cooling water, as well as dock lifting water level,

2、 The specific speed of mixed flow pump is higher than that of centrifugal pump, but lower than that of axial flow. Its head is higher than that of axial flow and lower than that of centrifugal flow. Its flow rate is smaller than that of axial flow and higher than that of centrifugal flow. It is mainly used in agricultural tank. In addition, the circulating water pump of power station replaces axial flow with mixed flow in urban drainage. It is a trend to manufacture large-scale mixed flow pump in China in 1970s

3、 Vortex pump is also known as vortex pump, regeneration pump has small flow and high head 1. Generally, the tooth shaped impeller of vortex pump, such as multi-stage centrifugal pump, has poor cavitation performance and is not suitable for conveying viscous liquid instead of low specific speed centrifugal pump with small flow, high head and simple structure. It is better than other pumps under low power conditions. Chemical industry, petroleum, shipbuilding, especially in chemical fertilizer, rubber, chemical fiber and medical treatment, The centrifugal vortex cavitation is good, the head is higher than the general, the feed water of small power boiler is changed into different materials, and can also transport gasoline, kerosene and