Requirements for compressed air for textiles

Analysis of Technical Requirements for Compressed Air System in Textile Industry

as an important application field of compressed air, the textile industry has strict requirements on air source quality, pressure stability and system energy efficiency. The following from the air quality, pressure control, energy-saving design and system reliability four dimensions, for your detailed analysis of textile compressed air technical standards and solutions:

1. Air Quality Requirements

textile production requires high cleanliness of compressed air, and strict control of oil, water and dust content is required to ensure product quality and equipment life:

1. oil content control
   • the oil content of compressed air shall be ≤ 0.1 mg/m & sup3;(some high-end processes require ≤ 0.01 mg/m & sup3;). Oil stains will pollute the surface of the fabric, block the nozzle of the air-jet loom, increase the resistance of weft insertion, and even cause equipment failure.
   • Solution: Use oil-free screw air compressor or configure high-efficiency oil removal filter (accuracy ≤ 0.01 μm) to ensure that the compressed air is free of oil pollution.
2. Water content control
   • the pressure dew point shall be ≤ 4 ℃ (equivalent to ISO 8573-1 Class 4 standard) to prevent corrosion caused by pipeline condensate and to prevent water droplets from contaminating the cloth surface.
   • Solution: Configure a refrigerated dryer or an adsorption dryer to reduce the pressure dew point of the compressed air to below -20°C to ensure that the output air is dry and clean.
3. dust content control
   • solid particle content should be ≤ 1 mg/m & sup3;, particle size ≤ 1μm (in line with ISO 8573-1 Class 2 standard) to reduce equipment wear and cloth surface defects.
   • Solution: Adopt multi-stage precision filter combination (main filter, dust filter, activated carbon filter) to filter impurities step by step.

2. pressure stability requirements

textile machinery is sensitive to air pressure fluctuations, and it is necessary to ensure that the gas supply pressure is stable to meet the process requirements:

1. gas pressure range
   • air-jet loom: The air pressure of the main nozzle is 0.25-0.4MPa, the air pressure of the auxiliary nozzle is 0.3-0.45MPa, and the pressure fluctuation should be ≤ 0.01MPa to ensure the flight stability of weft yarn.
   • Other equipment: For processes such as pneumatic pressurization and automatic doffing, the pressure requirement is 0.6-0.8MPa, and the air supply pressure shall be matched according to the equipment specifications.
2. pressure fluctuation control
   • fluctuation of air pressure can cause fabric surface defects (such as weft breakage and weft shrinkage). The following measures shall be taken to stabilize the pressure:
     • equipped with gas storage tank (volume ≥ 10%-20% of total gas consumption) to buffer pressure fluctuation.
     • The variable frequency screw air compressor is used to dynamically adjust the output power according to the air consumption and reduce the loading and unloading frequency.
     • Implement pipe network partial pressure gas supply, separate piping for equipment with different pressure requirements to avoid mutual interference.

3. energy saving design requirements

the compressed air system of textile mills accounts for a high proportion of energy consumption (usually up to 10%-15% of the energy consumption of the whole plant), and energy saving and consumption reduction shall be realized through the following schemes:

1. equipment selection optimization
   • large gas consumption scenario: Choose centrifugal air compressor, energy efficiency ratio (specific power) ≤ 5.5kW/(m & sup3;/min), suitable for continuous and stable gas demand.
   • small batch multi-species production: Using permanent magnet variable frequency screw air compressor, part of the load energy efficiency increased by more than 30%.
   • Local high-precision gas: Equipped with oil-free scroll air compressor to meet the oil-free needs of the processes such as adding bombs and air-jet twisting.
2. System optimization measures
   • intelligent centralized control: Monitor the running status of multiple air compressors through the Internet of Things platform, start and stop the equipment on demand, and avoid the phenomenon of "big horse-drawn trolley.
   • waste heat recovery: Use the waste heat generated by the operation of the air compressor (about 70%-80% of the input power) to provide heating or preheating process water for the workshop.
   • Leak Detection: Regularly inspect the pipe network with ultrasonic leak detector to repair the leak point (& phi; The annual leakage of 1mm leak can reach 12000 m & sup3;).

4. System Reliability Requirements

as the "lifeline" of textile production, compressed air systems need to have high reliability to avoid downtime losses:

1. redundant design
   • spare air compressor (N +1 redundancy) shall be configured to ensure that the system can still maintain more than 80% of the air supply capacity when a single equipment fails.
   • The key equipment (such as dryer and filter) adopts the configuration of one use and one standby, and the operation is switched regularly.
2. Preventive Maintenance
   • make a maintenance plan: replace the air filter/oil filter every 2000 hours, replace the lubricating oil every 4000 hours, and overhaul the main engine every 8000 hours.
   • Condition monitoring: through vibration analysis, oil detection and other means, the equipment hidden trouble is found in advance.
3. Emergency Response
   • configure the UPS power supply to ensure that the control system can still operate for more than 30 minutes when the power is off.
   • Establish emergency gas supply plan, such as renting mobile air compressor, to deal with sudden failure.

Configuration Scheme for 5. Typical Application Scenarios

6. summary and suggestions

compressed air systems in the textile industry need to take into account air quality, pressure stability, energy efficiency and reliability. Enterprises in the selection, it is recommended that:

1. clear process requirements: Determine the pressure/flow parameters according to the specifications of air-jet looms, elastics and other equipment.
2. Priority oil-free design: Choose oil-free screw or centrifugal air compressor to reduce post-processing costs.
3. Implement intelligent control remote monitoring, energy efficiency analysis and fault warning are realized through the Internet of Things platform.
4. Establish maintenance system: Develop preventive maintenance plans to extend equipment life and reduce life cycle costs.

Through scientific design and fine management, textile enterprises can build an efficient, stable and energy-saving compressed air system to provide a solid guarantee for improving product quality and production efficiency.