1. What is air? What is normal air?
Answer: The atmosphere around the earth, we are used to call it air.
The air under the specified pressure of 0.1MPa, temperature of 20°C, and relative humidity of 36% is normal air. Normal air differs from standard air in temperature and contains moisture. When there is water vapor in the air, once the water vapor is separated, the air volume will be reduced.
2. What is the standard state definition of air?
Answer: The definition of the standard state is: the air state when the air suction pressure is 0.1MPa and the temperature is 15.6°C (the domestic industry definition is 0°C) is called the standard state of the air.
In the standard state, the air density is 1.185kg/m3 (the capacity of air compressor exhaust, dryer, filter and other post-processing equipment is marked by the flow rate in the air standard state, and the unit is written as Nm3/min ).
3. What is saturated air and unsaturated air?
Answer: At a certain temperature and pressure, the content of water vapor in humid air (that is, the density of water vapor) has a certain limit; when the amount of water vapor contained in a certain temperature reaches the maximum possible content, the humidity at this time Air is called saturated air. The moist air without the maximum possible content of water vapor is called unsaturated air.
4. Under what conditions does unsaturated air become saturated air? What is “condensation”?
At the moment when unsaturated air becomes saturated air, liquid water droplets will condense in the humid air, which is called “condensation”. Condensation is common. For example, the air humidity is high in summer, and it is easy to form water droplets on the surface of the water pipe. In the winter morning, water droplets will appear on the glass windows of the residents. These are the humid air cooled under constant pressure to reach the dew point. The result of condensation due to temperature.
5. What is compressed air? What are the characteristics?
Answer: Air is compressible. The air after the air compressor does mechanical work to reduce its volume and increase its pressure is called compressed air.
Compressed air is an important source of power. Compared with other energy sources, it has the following obvious characteristics: clear and transparent, easy to transport, no special harmful properties, and no pollution or low pollution, low temperature, no fire hazard, no fear of Overload, able to work in many adverse environments, easy to obtain, inexhaustible.
6. What impurities are contained in compressed air?
Answer: The compressed air discharged from the air compressor contains many impurities: ①Water, including water mist, water vapor, condensed water; ②Oil, including oil stains, oil vapor; ③Various solid substances, such as rust mud, metal powder, rubber Fines, tar particles, filter materials, fines of sealing materials, etc., in addition to a variety of harmful chemical odor substances.
7. What is the air source system? What parts does it consist of?
Answer: The system composed of equipment that generates, processes and stores compressed air is called an air source system. A typical air source system usually consists of the following parts: air compressor, rear cooler, filter (including pre-filter, oil-water separator, pipeline filter, oil removal filter, deodorization filter, sterilization filter devices, etc.), stabilized gas storage tanks, dryers (refrigerated or adsorption), automatic drainage and sewage dischargers, gas pipelines, pipeline valves, instruments, etc. The above equipment is combined into a complete gas source system according to the different needs of the process.
8. What are the hazards of impurities in compressed air?
Answer: The compressed air output from the air compressor contains a lot of harmful impurities, the main impurities are solid particles, moisture and oil in the air.
Vaporized lubricating oil will form an organic acid to corrode equipment, deteriorate rubber, plastic, and sealing materials, block small holes, cause valves to malfunction, and pollute products.
The saturated moisture in the compressed air will condense into water under certain conditions and accumulate in some parts of the system. These moistures have a rusting effect on components and pipelines, causing moving parts to be stuck or worn, causing pneumatic components to malfunction and air leakage; in cold regions, moisture freezing will cause pipelines to freeze or crack.
Impurities such as dust in the compressed air will wear the relative moving surfaces in the cylinder, air motor and air reversing valve, reducing the service life of the system.
9. Why should compressed air be purified?
Answer: Just as the hydraulic system has high requirements for the cleanliness of hydraulic oil, the pneumatic system also has high quality requirements for compressed air.
The air discharged by the air compressor cannot be used directly by the pneumatic device. The air compressor inhales the air containing moisture and dust from the atmosphere, and the temperature of the compressed air rises above 100°C, at this time, the lubricating oil in the air compressor also partially turns into a gaseous state. In this way, the compressed air discharged from the air compressor is a high-temperature gas containing oil, moisture and dust. If this compressed air is directly sent to the pneumatic system, the reliability and service life of the pneumatic system will be greatly reduced due to poor air quality, and the resulting losses often greatly exceed the cost and maintenance costs of the air source treatment device, so the correct selection An air source treatment system is absolutely necessary.
Post time: Aug-07-2023
