Acquired by Cargill in 2008, Freeman’s of Newent are a primary chicken processing business, supplying independent butchers and the retail food sector.
As part of their drive to improve energy efficiency the management commissioned a site review to understand the opportunities to reduce energy consumption.
The spiral refrigeration plant used to chill chickens prior to packing and despatch was highlighted as a major energy user that should be investigated.
The system comprises five large Sabroe reciprocating compressors, operating on the R22 replacement refrigerant R417a, and provides cooling for a line which processes 72,000 chickens a day.
Due to the site having a limited electrical supply, power for this area is provided by 2 large oil fired generators.
Freeman’s approached Excalibur to investigate the possibilities of improving the efficiency of this system. A detailed study and modelling of the refrigeration system showed that there was potential to reduce energy consumption by more than 30%.
Excalibur were contracted to undertake the proposed modifications which included the installation of Liquid Pressure Amplification and inverter control of condenser fans. This allows the compressors to be re-commissioned to operate at low head pressure, reducing compressor energy consumption and increasing refrigeration capacity.
The effects of the modification were immediate; production was increased due to lower temperatures in the chiller, as a result of the LPA system delivering better quality liquid refrigerant to the expansion valve.
Oil consumption for the generators, which provide the electrical supply dropped by over 1000 litres / week, with the project achieving a return on investment of 18 months, and an annual reduction in carbon emissions of 150 tonnes.
"As a result of this project, our refrigeration in this area has been far more reliable and the energy reduction has been inline with our expectation."
Steve James, Site Manager