TABLE OF CONTENTS

GEA Add on heat pump for dairy HEAT recovery
Introduction
Robert Wiseman Dairies (RWD), the largest fresh milk supplier in the UK, uses significant
amounts of cooling to maintain food freshness, together with heat, which is used for
pasteurisation and cleaning in place (CIP). Climate and environmental protection are
high priorities at RWD:
• By 2030, RWD plans to eliminate synthetic refrigerants from its plants and replace
them with natural substances;
• By 2015 the company aims to reduce its gas consumption.
With these considerations in mind a design study was undertaken to incorporate an
ammonia-based heat pump that would use waste heat from the refrigeration cycle
to boost pasteurising temperatures and thereby remove the need for a natural gas
boiler. Following the study, an innovative ammonia heat recovery unit was installed in
partnership with GEA.
About the company
GEA Refrigeration Technologies is a leading global
group in industrial refrigeration. GEA designs,
engineers, installs, and maintains innovative key
components and technological solutions.
More information at:
www.geagroup.com
Contact Information
Henrik Winther
henrik.winther@geagroup.com
About the System
The project objective was replace 3 ageing R22 water cooled chillers with a capacity
of 2,500 kW with a central ammonia based refrigeration plant. Although replacing
the R22 chillers with an NH 3
solution would give significant performance increases,
the increased capital cost resulted in a poor return on investment (ROI) of 11 years.
To improve the ROI GEA proposed a comprehensive solution including refrigeration
capacity and the recycling of process and exhaust heat.
In a typical dairy such as the RWD Manchester site, the milk is cooled down to 2°C when
it arrives, then a boiler is used to generate steam, which is used to pasteurise the milk,
and through refrigeration the heat is removed using an evaporative condenser, cooling
the milk back down to 2°C. This process generated a lot of waste heat. To improve the
process a heat pump was put forward as a solution for the dairy’s heating requirements,
providing 80°C water for the pasteurisation process to replace the steam.
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