Air source device of air motor and compressed air purification
The air supply system is a compressed air power source that meets the requirements for pneumatic equipment. Vane air motor has relatively high requirements for compressed air, compressed gas to be dry, compressed gas to contain lubricating oil. If the compressed air contains moisture then the blade motor cavity will rust, will cause the blade to jam, causing the motor not to work, some customers let the motor directly without filtered compressed air, work for a while suddenly do not turn, back to my factory after we check the motor blade stuck a lot of rusty iron filings into it, should be the pipeline long-term use of unfiltered compressed gas caused by pipeline rust, when the rusty iron filings through the compressed gas into the motor cavity so that the motor can not work, Therefore, it is best to use filtered compressed gas when using air motors. To add some lubricating oil to the compressed gas, the vane motor speed is relatively high, and adding some lubricating oil appropriately will extend the service life of the motor.
In the working and pneumatic control system of the air motor, compressed air is the working medium.
The main functions of compressed air in pneumatic systems are as follows:
(1) Determine the status of the sensor;
(2) processing signals;
(3) Control of the actuator by means of a control element;
(4) Realization of actions (actuators).
(5) The normal use of the air motor determines the service life of the air motorPhysical properties of air
1. Air humidity and dew pointAir in nature is made up of a mixture of many gases.
Its main components are nitrogen (N2) and oxygen (O2), other gases account for a very small proportion, in addition, the air often contains a certain amount of water vapor. The amount of water vapor depends on the humidity and temperature of the atmosphere. The air containing water vapor is called wet air, and the air in the atmosphere is basically wet air; Air that does not contain water vapor is called dry air. The composition of dry air in the standard state (i.e. temperature of 0°C and pressure of p=0.1013 MPa) is shown in the table.
Ingredient | N2 | O2 | Ar | CO2 | Other gases |
volume fraction/% | 78.03 | 20.93 | 0.932 | 0.03 | 0.078 |
Mass fraction/% | 75.50 | 23.10 | 1.28 | 0.045 | 0.075 |
The pressure of wet air is called full pressure p, which is the sum of the partial pressure pg of dry air and the partial pressure ps of water vapor, that isp=ps+pg
Partial pressure refers to the pressure that each component gas of wet air has when it occupies the total volume of wet air at the same temperature.
The usual atmospheric pressure refers to the full pressure of wet air.Dew point refers to the specified air pressure, when the temperature drops until it becomes saturated,The temperature at the moment when the water vapor begins to condense. Dew point can be divided into atmospheric pressure dew point and pressure dew point, atmospheric pressure dew point refers to the condensation temperature of moisture under atmospheric pressure. Figure 9-1 shows the grams of moisture per cubic meter of atmosphere in the range of -30 °C~+80 °C, while the pressure dew point refers to the condensation temperature of the air pressure system at a certain high pressure. Taking an air compressor as an example, its suction port is the atmospheric pressure dew point, and the output port is the pressure dew point.
Density of air
Air has a certain mass, and its density is the mass of air per unit volume, denoted by ρ, ieP=M/V
where m represents the mass of the air (kg); V represents the volume of air (m3).
The density of air is related to temperature and pressure, which satisfy the gas equation of state.
In pneumatic control systems, compressed air is the working medium.
The main functions of compressed air in pneumatic systems are as follows:
(1) Determine the state of the sensor;
(2) Processing signals;
(3) Control the actuator through the control element;
(4) Implement the action (executive element).
The air supply system is a compressed air power source that meets the requirements for pneumatic equipment. The air source system is generally composed of an air pressure generating device, a compressed air purification treatment device and a transmission pipeline system. A typical air supply and air purification treatment system is shown in the figure.