Objective To demonstrate that vapor compression by means of a gas engine driven screw compressor shows high reliability and considerably reduces the energy consumption of the brewing process.The plant runs successfully and is distinguished by high reliability with minimum costs for operation and maintenance. Numerous measurements have shown that in the field less fouling of the vapor condenser occurs than had been assumed. The condenser is only cleaned once a week, without any appreciable increase in the condensate pressure being noted towards the end of the week. The screw compressor, which is subject to only slight fouling, has so far not needed any cleaning.The integration of the vapor compression system in the brewing process has had no influence on the process as a whole. Energy measurements of the system have yielded the high primary energy ratio (usable heat/gas energy input) of 6.95 (with respect to the gross calorific value of natural gas) and 7.65 (with respect to the net calorific value). The annual saving in energy is about 1 million cubic meters of natural gas. This means an energy saving of 89 %.Unfortunately the efficiency of the screw compressor is less than expected and therefore the brake horse power higher than calculated. Presumably the water injection, which keeps the vapor output temperature down, has a greater influence in reducing efficiency than had previously been assumed. The electromagnetic clutch is the chief cause of vibrations. With the help of suitable balancing experiments, however, vibration can be reduced to an acceptable level. Economic feasibility calculations show that vapor compression plants have good market prospects in breweries with more than 1,400 brews per year (at present gas prices). In designing a brewery, this number can be achieved by a proper layout of the wort copper.By means of an internal combustion engine driven vapor compression plant the energy consumption in a brewery can be considerably reduced. The energy saving is achieved by increasing the temperature of the waste vapor during compression and subsequent release of the heat back to the wort and by using the waste of the combustion engine in the brewery. The demonstrated vapor compression plant is installed in a brewery with an annual output of 1200000 hl of beer.The waste vapor (5.4 t/y, 1 bar, 100 deg. C) coming from the wort copper (normally exhausted to the air) is pumped by the screw compressor driven by a gas engine (187 kW) up to 1.3 bar and 110 deg. C. The hot vapor is condensated in the vapor thermostar by heating the wort (3.3 MW). The hot condensate leaving the vapor condenser is cooled down by an additional heat exchanger (462 kW). This heat is used together with the usable waste heat from the gas engine (450 kW) for hot water production needed in the brewery. With a primary energy input (natural gas) of 550 kW and the usable heat output of 4,212 kW a primary energy ratio of 7.65 is yielded. Programme(s) ENG-ENALT 1C - Programme (EEC) of financial support for projects to exploit alternative energy sources, 1979-1984 Topic(s) 1.6 - INDUSTRY Call for proposal Data not available Funding Scheme DEM - Demonstration contracts Coordinator MAN TECHNOLOGIE GMBH EU contribution No data Address DACHAUER STRASSE 667 POSTFACH 50 04 26 8000 MÜNCHEN Germany See on map Total cost No data
