PETpla.net Insider 05 / 2019

COMPRESSORS PET planet Insider Vol. 20 No. 05/19 www.petpla.net 20 COMPRESSORS Atlas Copco’s new ZD line has been developed specifically for PET bottle blowing (see issue 12). The company took a fresh look at some other aspects of a PET compressor, which had previously been regarded as unalterable characteristics of a 40 bar system: A first in PET com- pressor design is the piston com- pressor’s integral concrete base plate which eliminates the need for special foundations of any type and allows the compressor to be picked up and moved by fork-lift. The base- plate absorbs all of the vibration, with no transmission to the ground. The base plate also includes buffer capacity for 10 bar air - no need for a separate 10 bar receiver. In combination with a newly developed silencer housing it is now possible to locate the compressor in close prox- imity to the blowing machine. 20 05 1998 saw the introduction of the LMF EcoPET range of com- pressors with smooth speed regula- tion. Seven years later we reported in issue 9 on the extension of some models (from 950-2,700 m³/h) and the development of Eco-Speed- Control for efficient use of com- pressed air. A single-stage, oil-free, rotary blower is used as what LMF call their booster (the term booster normally being applied to the latter, i.e. piston stages of a multi-stage system). Its strong point lies in its ability to compress large quantities of air at low pressures. To cater for the periods under partial load, typi- cal of a blowing air compressor, LMF developed and introduced the Eco- Speed-Control. The advantage of this system is that only the booster (rotary blower) is controlled by a frequency converter that matches it to the final pressure of the unit as a whole. This means that the piston compressor downstream is fed with less air, so reducing its power requirement proportionally. PETpoint exhibition in Septem- ber 2005 saw the unveiling of Atlas Copco’s latest compressor system ZD, developed specifically for PET bottle blowing (see also 12/2004). 20 0 6 In issue 11+12, LMF Aus- tria discussed the topic of air recov- ery and demonstrated the possible savings if the compressed air is fed directly back into the blowing com- pressor using the patented EcoPET C.A.R. (Compressed Air Recovery) after the stretch blowing process. The pressure level of the return air, which is available for further use, is between 6 and 18 bars, and the amount of air fed back into the compressor can be between 0-80%. This optimised air control system is made possible by the use of “smart” valves integrated in the compressor control circuit. 2 0 08 At the 2008 edition of Brau Beviale, Kaeser Kompressoren featured a powerful booster used to deliver air at up to 45 bar as well as the compact “Sigma PET Air” complete compressed air system for stretch blow moulders. Also on show was the Kaeser screw compressors and the “Sigma Air Manager” which controls and adjusts the flow and pressure from several compressors for maximum economy and efficiency (issue 10) 2 0 09 Gardner Denver Ltd used Drinktec to show its new VH25 oil-free compressor for PET bottle blowing and a new, low-maintenance, shaftless and water-cooled motor, as reported in issue 10. In common with other com- pressors in its VH range, the VH25 fea- tures its AirPET air recovery system, which is designed to accommodate a returned pressure from the blow moulding machine that can be recycled back through the compressor. At PETpoint, Kaeser Kompres- soren exhibited its new dry-running rotary screw compressors and the ‘Airbox Centre’ – a compact compres- sor system offering all-in-one com- pressed air production, treatment and storage. The compact system is an all-in-one solution for compressed air production, treatment and stor- age, with a dry-running industrial reciprocating compressor at its core, providing free air delivery of 0.9 cubic metres (issue 9, photo above right). 20 11 Compressor coordina- tion and regulation: In issue 4, ABC Compressors presented its works on savings in compressor central units and made recommendations to guide distribution line set-up. Coordinating the work done by all the compressors together helps to provide energy sav- ings in a number of ways: it minimises the number of compressors running idle and the number of start-ups; it helps to stop machines that are not required and identify which compres- sors should be adapted to total air demand at any time; and covers pos- sible compressor stoppages due to maintenance requirements or break- downs. 20 14 The name is Vito. In PET- planet 1+2 we introduced Siad’s new compressor technology, the result of a complete re-think both of the design and production of an entirely new compressor concept. The new model should be suitable for all performance categories above 1,200m3/h, with variable speeds to ensure flexibility in production. Covering all performance ranges with just one compressor gen- erates cost savings in the manufac- turing process: a number of identical parts can be used. This of course includes the pistons, piston rod and crankshaft.