Energy savings through use of low-pressure steam re-compression in a brew kettle with interior cooker.

Klein-Carl, G. and Reichert, R.

Abstract
A new type of wort copper, combining vapour compression with an internal boiling heater (a combination which prior to the development of this system was widely believed to be impossible) is described. In the boiling process, heating takes place in 3 stages: (1) prewarming, using a steam heating element in the bottom of the copper. (2) When a preset temperature is reached, the annular heating element suspended within the copper is fed with very hot water. This sets up convection currents which cause the wort to circulate through the tube of the heater, ensuring even heating of the entire body of wort. (3) When sufficient vapour has been given off, the vapour compressor is switched on and takes over the task of heating the wort, so that the internal heater can be turned off once the condensed vapour reaches a sufficient temperature. From this point onwards, the only energy input is the electricity powering the compressor. The energy savings amount to an 87.5% reduction in the energy consumed by wort boiling (i.e. a cut of 40.6% in the energy consumption of the brewhouse as a whole). Other advantages include the complete elimination of wort vapour emissions (regarded by many people as a nuisance, and consequently subject to legal restriction in Germany and other countries) and a low susceptibility to fouling (which saves on cleaning costs and associated difficulties). Since the original copper of this type was installed at the Loewenbrauerei, Schwaebisch Hall, Germany, 2 others have been fitted in other breweries and another was under construction at the time of writing.
Keywords : brewhouse compressor economisation energy equipment heating vapour wort boiling wort copper