The production of screw compressors, which have since become one of the most important products made by AERZEN, began during the Second World War. At that time, the Reich Ministry for Armaments and War Production instructed Managing Director Karlheinrich Heller to design a screw compressor, intended to serve as an exhaust gas compressor in new submarine types. After a period of negotiations lasting two years, AERZEN was awarded a sub licence by the Swedish company Ljungströms Angurbin, now Svenska Rotor Maskiner AB. During the 1930s, Chief Engineer Alf Lysholm developed the prototype of the modern screw compressors for use in gas turbines.
In 1943, manufacturing of the new product line began. As twin-shaft positive dis- placement machines, the screw compressors optimally supplemented the range of products. Concerning oil-free handling with internal compression they achieved higher compression ratios than positive displacement blowers.The first “K60” screw compressor manufactured in Aerzen, called helical blower or rotary positive displacement compressor, had an asymmetrical rotor profile accord- ing to the Lysholm principle.
From the beginning, Heller had planned a universally applicable screw compressor which could be equipped according to a modular system. His plan ultimately became a reality. Now, screw compressors made by AERZEN cover all the fields of application of air and gas compression. They are used, for example, for pneumatic conveying, for the industrial generation of compressed air, at chemical companies, power plants, steel production plants and also in the refrigeration industry and in process gas technology.
Economic miracle brought prosperity
But at the end of the Second World War, instead of complex technologies, it was beetroot juice presses, oil mills and tobacco cutters which were produced.
In spite of the difficult post-war situation, AERZEN soon resumed the production of twin-shaft positive displacement machines - dismantling of the production facilities by the allies was avoided. The economic miracle of the 1950s and 1960s also brought prosperity for AERZEN. Numerous new products took the company forward. During the years that followed, AERZEN continued its investment and modernisation strategy. When the company celebrated its 100th anniversary in 1964, the machinery range had been extended with ultra-modern special machines.
In 1967, the production of special air compressors for higher pressures began. The VM-series for oil-free compression of air was equipped with ball bearings. The new screw compressors minimised the risk of contamination during the pneumatic transport of grain, cement or chemical bulk material.
In 1968, at the Hanover Fair, AERZEN presented for the first time screw compressors with oil-injection for refrigeration technology. The new VMY series were mainly used in refrigerated food warehouses and in air-conditioning systems on ships.
With the new VMX series of screw compressors with oil-injection for compressed air technology, the company gained entry into new fields of application in 1971.
World’s largest positive displacement blower
In 1978, AERZEN presented the world’s largest positive displacement blower, the huge piston of which, with a diameter of 1.5 metres and a drive capacity of 3 mega- watts, could convey 84,000 cubic metres of process gas per hour. To manufacture this giant, the hall doors had to be enlarged and larger piston planing machines and milling machines had to be procured. Regarding volumetric handling of gas, AERZEN successfully extended the previously technically feasible field of application of a positive displacement blower. The new blowers enjoyed and still enjoy today high demand in the steel production sector.
AERZEN experienced a similar success story with the development of the world’s largest screw compressor in 1984. With a rotor diameter of 845 millimetres, it could compress about 65,000 cubic metres of process gas per hour.
The special machines were supplied to soda factories in France and Italy - consequently to a branch which had relied on turbo compressors before. You can read in our next edition about the product innovations that followed in the ensuing years.