Note - vacuum pump classification and selection

refers to the use of mechanical vacuum pump, physics, chemistry or physical chemistry method emptying pumping container for vacuum device or equipment. In general, the vacuum pump is to use various methods to improve, and maintains the vacuum device in enclosed Spaces.

vacuum pump classification

according to the working principle of vacuum pump, vacuum pump can be divided into two categories, basically can be variable capacity pump and momentum transfer pump.

the variable capacity pump is a vacuum pump, which makes use of the periodic pump cavity volume changes to complete suction and exhaust, so as to achieve the aim of extraction. Before leaving the pump cavity compressed gases.

momentum transfer pump ( Molecular pump) Rely on high speed rotating blade or high speed jet momentum transfer to the gas or gas molecules, so that the gas from the entrance of the pump continuous transmission to its exports.

the variable capacity pump can be divided into: reciprocating and rotating ( Rotary vane, slide valve, the liquid ring, pouring area, spiral, claw rotor) And other types.

casting area and cold knife area equipment using the variable capacity pump. The following detailed description the variable capacity pump.

the variable capacity pump classification

1, reciprocating vacuum pump

through the reciprocating motion of the piston in the pump chamber, the gas is inhaled, compression and discharge. Also known as the piston vacuum pump. For details, please see the following video:

2, rotary vane vacuum pumps

use of the rotation of the rotor of the pump cavity parts movement, gas is inhaled, compression and discharge. It is roughly divided into the following categories:

1) Oil seal vacuum pump

it is a kind of revolving variable capacity pump, it USES the vacuum pump oil seal gaps between the moving parts in the pump, and reduce harmful space in the pump. The pump is usually angry town of equipment. It mainly includes the rotary vane vacuum pumps, fixed vane vacuum pumps, vacuum pump and vacuum pump.

2) Liquid ring vacuum pump

in the pump housing with the eccentricity of the rotor. When its spinning, working fluid in the pump shell is thrown, the formation and the liquid ring pump casing concentric. In the formation of liquid ring and the rotor blade has a small volume change periodically several variable displacement of suction and discharge chamber. Working fluid is usually water or oil, so also known as oil ring vacuum pumps or water ring vacuum pumps.

3) Dry vacuum pump

this is a variable capacity pump, is not in the pump oil ( Or liquid) Seal. Because of the dry vacuum pump don't need a working fluid in the pump cavity, so is suitable for the need to clean oil free vacuum environment of the semiconductor industry, chemical industry, pharmaceutical industry and food industry in the application process. Internal grinding equipment factory is the vacuum pump, no liquid seal.

4) Pouring area 0 vacuum pump is equipped with two double leaf or lobed rotor, they rotate along the opposite direction at the same time. Between the rotor and rotor and the pump shell inner wall to keep a certain gap between.

choose which parameters need to be paid attention to when the vacuum pump?

1, vacuum pump pressure limit

the limit pressure of the pump unit for Pa, refers to the pump at the entrance is equipped with standard tests cover the minimum pressure at work and in accordance with the specified conditions.

2, vacuum pump, pumping speed

the pumping speed of the pump unit for cubic meters per second or L/S, this means that when the pump is based on the specified condition is equipped with standard tests cover and the work, the gas from the test cover traffic flow, and the location on the measured test cover balance pressure ratio. Referred to as the pumping speed of the water pump.

3, vacuum pump suction

vacuum pump unit for Pa cubic meters per second or Pa L/S. Refers to the pump inlet flow of gas.

4, vacuum pump start-up pressure

vacuum pump start-up pressure units for Pa, refers to the vacuum pump is started without damage and have the pressure of the pumping action.

5, the first level of the pump pressure

before the vacuum pump pressure units for Pa, refers to the exhaust pressure lower than that of a vacuum pump outlet pressure of the atmosphere.

6 level, vacuum pump before the biggest pressure

the level before the biggest pressure unit vacuum pump port is Pa, this means that it's more than the former class pressure may damage the pump.

7, the maximum working pressure of vacuum pump

the maximum working pressure of vacuum pump unit for Pa, refers to the corresponding to the maximum pumping quantity inlet pressure. Under the pressure, pump can work continuously without degradation or damage.

8, compression ratio

compression ratio is given the pump outlet pressure and the ratio of the inlet pressure of the gas.

9, pouring area coefficient

the ratio of the actual pumping speed on the pumping channel area and here based on the theory of molecular seepage calculation of the ratio of pumping speed.

10, pumping speed coefficient

the actual pumping speed of the pump and the theoretical calculated through molecular effusion at the entrance of the pump pumping speed.

11, reflux rate

reflux rate of pump unit is g/cm2. s。 It refers to when the pump work under prescribed conditions through the pump suction pump flow mass flow rate per unit area.

12, allow the amount of water vapor

the allowances unit water vapor is kg/h, is refers to the continuous operation under normal environmental conditions during gas ballast pump can remove water vapor quality.

13, maximum allowable steam inlet pressure

maximum permissible steam inlet pressure units for Pa. It refers to under normal circumstances, run continuously during gas ballast pump can remove the biggest steam inlet pressure.