Glass factory Noelle + von Campe GmbH in Boffzen on the river Weser produces high quality packings made of glass, mainly for foodstuff industry. Since the commissioning of a new factory in March 2009 the daily capacity is 480 tons! Various functions in a glass factory require a maximum pressure of 3,5 bar, other ranges only 2,1 bar. Furthermore compressed air with 6 bar maximum pressure as general service air must be available. “We wanted to supply in our new glass factory every working range only with the required pressure”, explains Dipl.-Ing. Heinz Fenke, Technical managing Director in the company for many years. “Each bar of not required higher compression costs us 6 to 7 per cent additional energy – i.e. cash.”
When subdividing into three compressed air systems and an additional vacuum system for glass moulding Noelle + von Campe entered new territory in this branch. Instead of generating the compressed air first of all with oil injected screw compressors and afterwards treating it oilfree, it should be produced immediately with oilfree screw compressors. This does not only reduce the pressure losses considerably, which saves energy. Also the prime costs and disposal costs for compressor oil and the oil-contaminated treatment components apply no longer. The service- and maintenance expenditure thus reduces considerably. Moreover, the risk of an oil contamination by a filter fracture is excluded completely. Furthermore all the machines were to be realized in water-cooled design. First of all it seemed, that these considerable requirements could not be met. “We only achieved the breakthrough with the help of SFA-Drucklufttechnik GmbH in Walsrode”, says Fenke. They recommended a customised compressed-air generation with eight oilfree compressing, mostly even speed-controlled Aerzen screw compressors. SFA Managing Director Frank Schauder: “Only with Aerzener Maschinenfabrik as partner we could offer a customised and especially energy-efficient solution.” Each 3,5- and 2,1-bar-compressor made by Aerzener is followed by a water-cooled, low-resistance heat exchanger as compressed-air cooler. The compressed air of the two 6-bar-compressors is recooled in two refrigeration dryers, a partial flow additionally in an adsorption dryer. For an absolutely safe supply if required compressed air can be fed into lower pressure ranges. An overriding control concept adapts the compressors dynamically to the requirement – so the most efficient compressor-combination is always running. A switched-off compressor is immediately replaced by other ones.
Concerning energy, maintenance and disposal the unit saves all in all costs of more than 350.000 Euros every year. With this SFA-Managing Director Schauder is as satisfied as the responsible persons at Noelle + von Campe: “As far as its conception is concerned this unit is unique and ahead of its times.”
