PETpla.net Insider 05 / 2019

COMPRESSORS PET planet Insider Vol. 20 No. 05/19 www.petpla.net 31 Nanjing Shangair Machinery Manufacturing Co., Ltd. is dedicated to developing advanced, effective and productive air compressors, with a particular focus on improvements in energy consumption. It describes itself as a high-tech enterprise that develops, manufactures and sells Shangair brand piston air compres- sors. It has more than 20 years of experience in blow moulding machin- ery and air source leak detection. It holds a number of patents in its areas of operations. The company designed and developed the “intelligent” hori- zontal symmetric balanced PET air compressors, which it says fill a gap for Chinese-origin, high-performance air compressors dedicated to PET blow moulding. The company has sold products to more than 60 countries and regions. It has provided systems and equipment to a range of beverage manufactur- ers in China, including Mengniu Dairy, Anhui Yingjia, Guangxi Shibu Dairy and VV Group. China’s only award-winning compressor design Shangair’s M-type symmetric balanced water-cooled oil-free air compressor is claimed to consume up to one-third less energy than tradi- tional angle-type oil-free compressors, and 5-10% less than European and American equivalents. It is the only air compressor product to have won the China Industrial Design Award. Traditional design The company states that tradi- tional L-type machines can have a number of disadvantages, which the M-type is designed to overcome, and continues that L-type compressors can suffer from strong vibration, and be very noisy. Even when equipped with variable speed drives (VSDs), it can be hard to operate them in an energy-efficient way. High failure rates and a short maintenance cycle, which interferes with production and leads to financial underperformance, can also be an issue. According to Shangair Machin- ery, these issues appear to be quite common in the L-type design, which features a vertical first-stage cylin- der, with horizontal cylinders in the second and third stages. This means that inertial forces are difficult to balance and lead to vibration and associated noise. When unbalanced, the design limits maximum speed and normal lubrication processes so that speed cannot get too low, which makes the speed range narrow. Even a VSD controller could then be unable to achieve any energy saving. Better by design Shangair claims that its M-type design overcomes these problems. In its design, the crankshaft crankpin has an angle of 180°, and the cor- responding pair of crankpins sit at 90°. The dynamic balance design make the first-order and second-order inertial forces of each column com- pletely balanced. The resultant force is zero, which means that the M-type compressor has very little vibration in operation. The first-stage suction port is equipped with patented suction buffer tank and suction noise filter technologies, which greatly reduce low-frequency noise, keeping them below 85 decibels. The equal-pressure ratio four- stage compression design is stated to help the M-type compressor to be more energy-efficient. This, along with its structural stability, enables it to achieve higher rotational speed. A wider speed range means that the VSD can deliver real energy savings. In daily use, M-type can be more than 15% energy-efficient than L-type com- pressors. Nanjing Shangair Machinery Manufacturing changes the shape of air compressors in China Award-winning design Among the biggest challenges for beverage manufacturers to overcome are: reliable operation of production lines, with no breakdowns or unscheduled stoppages, and energy con- sumption. Compressed air is an essential element in manu- facturing, production of PET bottles in particular. Air com- pressors have long been known to be significant consumers of energy and they are a focal point in operations; and their reliability is critical. If they fail, the consequences – such as delivery failures and quality problems – can be very signifi- cant and expensive. Hall 9.2 booth K71 COMPRESSORS M-type balanced structure Shangair’s M-type compressors for Anhui Yingjia Old screw-booster compressor of Anhui Yingjia