How to optimize compressed air in weaving process?

Indian textile industry which contributes to 7% of industry output in value terms, 2% of India’s GDP and to 15% of the country’s export earnings (Source – GOI Textile Min. Annual Report 2018-2019) constitutes weaving as a major method of fabric production. Weaving is a method of textile production in which two distinct sets of yarns or threads are interlaced at right angles to form a fabric or cloth using looms. These looms pre-dominantly were hand-held looms which are now replaced with power looms over time. These looms pre-dominantly were hand-held looms which are now replaced with Power looms over the years. The modern power looms (air-jet looms) in the weaving process have a growing need for compressed air for their operation and is an important utility. In air-jet weaving, the weft yarn is inserted into the warp shed with compressed air to accelerate and control the insertion of the weft. The key raw material used to produce cloth in weaving is yarn and electrical power wherein 80% of power cost is invested in generating compressed air. Hence, it is important to optimize the power cost involved in air-jet looms to increase profits.

Air-jet looms are versatile, high-speed machines with good quality output, but they consume more power as they require compressed air for the loom operation which makes them less preferable over traditional rapier looms. Did you know, 18% decrease in air consumption is accomplished by changing the process parameters consisting mainly of the blowing time of nozzles in a weaving mill. Here, it should be remembered that low SER (Specific Energy requirement) will not improve the overall power cost reduction. The air jet looms operating cost can be controlled by reducing the compressed air consumption by adopting the following methods. Compressed Air Generation

• Analysis of compressed air demand flow pattern, which is fluctuating due to loom changes, nozzle usage & operating speed.
  

A True VSD compressor (i.e. compressor with invertor duty motor/Permanent magnet motor, VFD drive, no blow-off) in combination with base load has potential of 50% power saving in utility plant.

• Avoiding compressor idling and blow off/down losses.

A VSD compressor should stop in pressurised conditions without blowing off compressed air.

• Adjusting pressure band to 0.5 bar(g) pressure will incur 3% more power.

A VSD compressor should run at fixed pressure setting of Set pressure +/- 0.1 barg.

Compressed Air Treatment;

• Selecting the right size of the dryer is important for both the quality of air and power consumption.

A correctly sized dryer to ensure air devoid of moisture can help and improve life of air nozzles and downstream equipment’s. A minimum recommendation is Class 1.4.1 as per ISO 8573-1 2010 standard which requires a suitable refrigeration dryer and a set of filters to deliver air quality class 1.

• Reduce pressure drops against the dryers and filters.

Modern hybrid 2 in 1 filters further help to reduce the pressure drop by 40% and save considerable energy. Likewise, the choice of low GWP (global warming potential) refrigeration dryers using CFC free green gases further help to reduce the negative impact on environment.

• When sizing air treatment products do take in consideration foreseen changes in inlet temperature & pressure for selection of dryer & filters for optimum results and unhindered productions. Over or under design can cause operational troubles.

Compressor with integrated accessories can save installation costs and utlity space.

Compressed Air Distribution;

• All the power saved in the right selection of compressed air systems can be wasted through a single leak or by pressure drops due to wrong pipe sizing & layout.

Do you know 1mm of leak can cause a energy loss 0.3KWh at 6 barg.

• The right-sizing of AirNet distribution is important along with the timely maintenance of the loom and fixtures. 

Right diameter of pipe and efficient joints of a pipe material with lowest friction factor can limit a pressure drop to 0.5 barg between generation and usage.

Compressed air is an integral part of the weaving process & textile industry and thus, it important to invest in right compressed air solutions which bring peace of mind with high energy savings. The smart compressed air solutions will help in bringing down the cost of compressed air with an efficient production process thereby substantially reducing the operating cost of the weaving mill.