What is the dust content of solid particles in the air of screw compressor?

Control standard and technical analysis of dust content in air solid particles of screw compressor

As the core air source equipment in the industrial field, screw compressors emit dust content of solid particles in compressed air that are directly related to the operation safety of downstream equipment and product quality. Based on comprehensive industry specifications and technical practices, the following explanations are given on relevant standards and technical points:

1. Core control indicators for dust content
According to general industry standards, the solid particle content of compressed air emitted by screw compressors should be controlled below 1 mg/cubic meter. This indicator is detected by a laser particle counter to ensure that the size and quantity of dust particles meet the classification requirements of ISO 8573-1 international standard. For example, the pharmaceutical manufacturing field requires particulate matter to be graded ≤1 (particle size ≤0.1μm, quantity ≤20,000 particles/m³), the food and beverage industry usually implements ≤2 standards, and general industrial applications need to meet ≤3 specifications.

2. Analysis of factors affecting dust content

1. Air intake quality control
   The dust content of compressed air is closely related to the intake environment. If the air filter is not maintained in time, dust accumulation will increase the risk of filter penetration. Experimental data shows that when the dust concentration exceeds 0.5 g/cubic meter, the filter element clogging frequency increases by 40%, and the compression efficiency decreases by 15%-20%. It is recommended to configure a three-stage filtration system, with the first-stage filtration accuracy ≥5μm and the last-stage filtration accuracy ≤1μm to form gradient protection.

2. Filtration system effectiveness
   Modern screw compressors mostly adopt composite filtration structures, including primary pre-filtration, precision filtration and activated carbon adsorption modules. Tests have shown that the filtration efficiency of high-quality filter elements on 0.3μm particles can reach 99.97%, and the life of the filter element can be extended by 3-5 times when combined with the pulse self-cleaning function. It should be noted that when the filter element pressure difference exceeds 0.05MPa, it should be replaced in time to avoid the risk of bypass leakage.

3. environmental worthiness design
   Under dusty conditions, it is recommended to add an intake pretreatment device. Practical data from a steel company shows that after installing a cyclone separator, the dust content in the compressor intake air dropped from 12mg/m³ to 1.2 mg/m³, and the filter element replacement cycle was extended to 8000 hours. For humid environments, a gas-liquid separator needs to be equipped to prevent moisture and particulate matter from forming a viscous mixture to block the filter material.

3. Dust content control technology path

1. multistage filtration system
   Adopt a three-level purification process of “inertial separation + fiber filtration + electrostatic adsorption”. The first-stage separator removes large particles of impurities, the second-stage fiber filter element intercepts micron-sized particles, and the last-stage electrostatic filter module captures nano-sized particles. After an automobile manufacturer applied this plan, the particulate matter content in compressed air in the coating workshop dropped from 0.8 mg/m³ to 0.15 mg/m³, and the particle defect rate of the paint film dropped by 78%.

2. Intelligent monitoring and maintenance
   Deploy online particle counters to monitor dust content in real time, and automatically start the blowback cleaning program when the value exceeds the warning value. Combined with the filter element life prediction model, a mathematical model is established through differential pressure sensor data to accurately predict the filter element replacement cycle and avoid excessive maintenance or extended use.

3. system optimization design
   The design of the pipeline follows the principle of “short, straight and few bends”, reduces the use of 90° elbows, and reduces secondary dust caused by turbulent airflow. Install automatic drain valves on key branches to ensure timely discharge of condensed water and prevent the formation of water-dust mixtures. Practice in an electronics factory shows that after optimization, the stability of dust content of the system is increased by 60%, and the equipment failure rate is reduced by 45%.

4. Industry application practical suggestions

• High-precision manufacturing: It is recommended to configure a dual-stage filtration system with a final filtration accuracy of 0.01μm and regular particle size distribution testing.
• Heavy industry scenarios: Adopt positive pressure dustproof machine room design to keep the pressure in the compressor room 5- 10Pa higher than the external environment to block dust intrusion into the channel.
• Food and pharmaceutical industry: Select 304 stainless steel pipes to avoid metal debris contamination, and conduct microbial sampling and testing before and after production of each batch of products.

Through the above technical measures, it is possible to ensure that the output air cleanliness of the screw compressor meets the stringent requirements of various industries, providing stable and reliable air source guarantee for the production system. Enterprises should establish a dust content monitoring ledger and formulate personalized control plans based on the characteristics of the production process to achieve balanced optimization of compressed air quality and operation and maintenance costs.