Noise standards for screw air compressors

Background on Noise Issues in Screw Air Compressors

Screw air compressors are widely used in industrial production, yet the noise they generate has increasingly drawn attention. Noise not only poses health risks to operators but can also contribute to environmental pollution. Consequently, understanding and complying with relevant noise standards is of great importance for ensuring regulatory compliance and protecting the environment.

Development and Classification of Noise Standards

The noise standards for screw air compressors are broadly categorized into two types: product‑factory‑outbound standards and plant‑boundary emission standards.

• Product出厂 standard:It primarily specifies the noise levels of air compressors under defined test conditions, ensuring that the equipment exhibits good acoustic performance during both the design and manufacturing stages. Typically, the noise level is required to remain within an acceptable range when the equipment operates at its rated conditions.
• Emission standards at the plant boundary:In accordance with the relevant national environmental noise emission standards, noise levels outside an enterprise’s premises must comply with the limit values applicable to the designated acoustic environment functional zone. Emission limits vary across different zones, and enterprises are required to ensure compliance based on their specific site selection.

Main Factors Affecting Air Compressor Noise

To effectively control noise, it is first necessary to understand its primary sources:

• Mechanical noise:It is generated by mechanical friction and vibration resulting from the engagement of the main‑shaft rotor, bearing operation, and motor rotation.
• Aerodynamic noise:This includes flow‑induced pulsation noise generated during the intake and exhaust processes, which constitutes the primary component of screw air compressor noise.
• Electromagnetic noise:Vibration and noise in the drive motor caused by electromagnetic field variations during operation.

Common Noise Reduction Measures and Compliance Recommendations

To ensure that screw air compressors comply with noise standards, enterprises can implement the following comprehensive noise-reduction measures:

• Installation of soundproofing facilities:Equip the air compressor with a dedicated soundproof enclosure lined with sound-absorbing materials to effectively block the transmission of mechanical and aerodynamic noise.
• Optimizing the intake and exhaust system:Install high-efficiency silencers at the air intake and exhaust ports to reduce high-frequency noise generated by airflow pulsations.
• Shock-absorbing treatment:Install vibration-isolating pads or dampers beneath the equipment base to reduce solid-borne noise and prevent vibrations from being amplified through the floor or building structure.
• Regular maintenance and servicing:Maintain equipment in good working condition by promptly replacing worn parts and lubricants to prevent abnormal noise caused by mechanical looseness or increased friction.

When selecting and installing screw air compressors, companies should conduct a preliminary assessment of the site’s acoustic environment, choose low-noise models, and carefully plan the compressor room layout to ensure that equipment operating noise complies with national and local environmental standards.