Pump selection principles and steps

Pump is a kind of a lot of wide range of general-purpose machinery and equipment, it is widely used in petroleum, chemical, electric power, metallurgy, mining, choose ship, light industry, agriculture, civil and defense departments, occupies an important position in national economy. According to 79 statistics, pump output reached 1.256 million units in China. Pump power consumption accounted for more than 21% of the national power consumption. So vigorously reduce pump energy consumption, to save energy use is of great significance.

Designed and developed in recent years, we have pump industry a lot of high efficiency and energy saving products, such as IHF, CQB, such as the FSB, UHB models of pump products, to reduce the energy consumption of the pump plays a positive role. But now in various fields of national economy, due to the unreasonable type selection, many of the running status of pump in the unreasonable operation efficiency is low, waste a lot of energy. And due to the unreasonable selection of pump, it was impossible to use, or use the maintenance cost increases, the economic benefit is low. Therefore, reasonable choose pump is of great significance to save energy.

So-called reasonable selected pump, is to consider investment and operation cost of pump unit and pumping stations comprehensive technical and economic indexes, such as make it conform to the principle of economy, safety and applicable. In particular, has the following several aspects:

Must meet the requirements of the use of flow and head, requiring the pump running work time points (device characteristic curves with the pump performance curve intersection) often remain within the range of efficient operation, save power and not easy attaint parts.

The choice of the pump should not only small volume, light weight, cheap, and has good characteristics and higher efficiency.

Has good resistance to cavitation performance, this can not only reduce the pump room of the excavation depth, and the water pump cavitation occurs, smooth operation, long service life.

Built according to the selected pump pumping station, the project less investment, low operating cost.

The second section selection steps

A basic data, list:

1, the characteristics of the medium: the name of the medium, specific gravity, viscosity, corrosive, toxic, etc.

In 2, medium contained in the body of particle diameter, how much content.

3, medium temperature (℃)

4, need traffic

General industrial pump can be ignored in the process of pipeline system leakage, but affected by the change of flow must be considered. Agricultural use, if is adopted, open channel water pump must also consider leakage and evaporation.

5, pressure: suction tank pressure, water pressure, the pressure drop of pipeline system (head losses).

6, pipeline system data (diameter, length, kinds and number of pipeline accessories, vacuum pressure to the pool geometry level, etc.).

Should also make the device characteristic curve, if necessary.

Decorate in the design line, should pay attention to the following items:

A, reasonable choose pipe diameter, pipe diameter is big, under the same flow rate, liquid flow velocity is small, small resistance loss, but the price is high, the pipe diameter is small, can lead to resistance losses increase sharply, increase the selected pump lift, installed with power increasing, the cost and operation cost are increased. So from the perspective of technical and economic comprehensive consideration.

B, discharge pipe and pipe joints should be considered are the biggest pressure.

C, pipeline layout should decorate straight pipe as far as possible, try to reduce the attachment and try to narrow the pipe length, pipe must turn, elbow bend radius should be 3 ~ 5 times the diameter of the pipe, as much as possible Angle is greater than 90 ℃.

D, the discharge side of the pump must be installed with the valve (ball valve or valve, etc.) and check valve. Used to adjust the point of pump, valve check valve when the fluid flow reversal can prevent the pump inversion, and makes the pump to avoid water hammer blow. (when the liquid flow back, will produce a great reverse pressure, make the pump damage)