Ammonia based upgrade at Wadworth Brewery

Wadworth brewery bosses are toasting a refrigeration system upgrade which will cut running costs and lead to a smaller carbon footprint. A new system installed by J & E Hall features two HallScrew compressors which ensure that a wide range of ales remain in tip-top condition throughout various key processes on the journey to the glass.

The ammonia-based system is at the heart of the Victorian plant in Devizes, Wiltshire, where beer has been brewed since 1875.

The new equipment serves a transfer beer chiller, a cask conditioning room, three cold rooms as well as several condition tanks involved in the cask conditioning and refining processes where temperature levels are key.

It was out with the old and in with the new as the four Veebloc reciprocating compressor set-up of two Halls V127s and two Halls V92s made way for an HallScrew HSO 3221 on fixed speed with slide valve control and an HallScrew HSO 3216 on a variable speed drive, running between 1250 rpm and 2500 rpm to match the production loads.

J & E Hall Fridgewatch controllers were used to control the new compressors and the inverter. These were connected to new control panels which were manufactured and installed within the project. The existing evaporator and condenser set-up was kept.

John Davies, J & E Hall Bristol Service Centre Manager explained: "We ripped out the old V127 compressors, installed the HSO 3221 and got that running alongside the old V92 reciprocating plant. In a second phase we then removed the V92 compressors and installed the smaller HallScrew with the variable speed drive."

Mr Davies said that savings can be expected with vastly-improved glycol temperature control: "With the new Fridgewatch control the glycol set point is constantly maintained at -6.5°C across all loads from one compressor running at minimum load to both compressors running at maximum load.

On commissioning the smaller HallScrew compressor and the inverter control we were able to increase the refrigeration duty of the V92 plant. The condenser had previously been oversize and we were able to give Wadworth an extra 30 per cent duty by matching the evaporator duty directly to the compressor duty by increasing the compressor speed. The inverter control allowed us to slowly increase the speed to the optimum speed to give us more refrigeration duty.”

Robert Tyre, chief engineer at Wadworth concluded "We would expect it to cut costs and lead to a smaller carbon footprint. The project caused the minimum amount of disruption. It was all on budget and all on target. From a production point of view it didn't disrupt us at all."