Application of screw type vapor recompression to wort boiling process.

Taki, S., Tsubota, Y. and Murakami, M.

Abstract
In cooperation with Mayekawa Mfg. Co. Limited a commercial scale plant using mechanical vapour recompression (MVR) was constructed at the Suntory Tonegawa Brewery and evaluated. The screw vapour compressor produced a large compression ratio up to 2 to 5 and a temperature differential of 20 degree C to 50 degree C, previously impossible with a single stage centrifugal compressor. It was resistent to mist, adaptable to load fluctuations and reliable in operation and performance. MVR was suited to the conventional wort kettle which was not pressure proofed and it was possible to use a conventional automatic hop dosing system with a pneumatic conveyor. The driving energy required was only about 31% of that needed by a conventional system. The heat exchanger outlet temperature could be controlled to + 0.5 degree C and the inner pressure of the kettle to within + 10 mm of water. The quality of wort and beer produced using MVR was not significantly different to that produced by conventional means. At Suntory trials are under way to apply MVR to the continuous distillation of alcohol. The system is expected to find energy saving applications in the food and chemical industries.
Keywords : boiling compressor economisation energy screw vapour wort