Chiller’s role in water reclamation

UK: A Turbomiser chiller system supplied and installed by Cool-Therm is providing cooling for a new water treatment and reclamation facility at a major UK food production plant.

The facility treats water used in cooking and processing ready meals, removing organic constituents and returning it in a purified, food-safe condition to the manufacturing process. Before the recycling plant was installed, the end user had to pay to have waste water transported offsite by tanker to be disposed of.

The plant, designed and operated by leading Worcester-based water treatment and reuse company Aquabio, is said to deliver significant savings by overcoming the need for such offsite disposal as well as avoiding the need for continuous inputs of fresh water to the manufacturing process.

Cool-Therm specified a 521kW TMA Turbomiser air-cooled chiller, equipped with dual-circuit evaporators and twin pumps, linked to two stainless steel brazed-plate heat exchangers. This allows run and stand-by operation to enable continuous 24/7 cooling in the event of planned maintenance or the unlikely event of a breakdown.

Aquabio is a leader in industrial membrane bioreactors (MBR), which use a combination of membrane-based filtration and aerobic or anaerobic digesters to provide high quality treated wastewater. Further reverse osmosis treatment provides reuse quality water.

The water reuse facility, operated by Aquabio on behalf of the end user, is located alongside the food production plant in Lincolnshire. Key factors determining the design and selection of the cooling system were running costs, including energy use and servicing, and reliability.

Martin Sharman, Cool-Therm’s midlands regional manager, said: “We worked closely with Aquabio during the design, planning and implementation stages in a consultancy capacity. The critical requirements for the chiller were reliability, resilience and efficiency. Turbomiser is supremely efficient and reliable, as has been proven in hundreds of installations across the country. Equipped with the dual circuit and twin pumps, it has the resilience to maintain cooling round-the-clock, every day of the year.”

Water is cleaned after the MBR using Aquabio’s reverse osmosis membrane technology, then passed at a temperature of up to 35.7ºC through one side of a brazed plate heat exchanger and returned at 12ºC back into the production system in a continuous process. The system is able to handle a flow rate of up to 40m3/hr.

The heat energy is discharged to atmosphere through dual evaporators, with cooled heat transfer water pumped into a buffer vessel to maintain a header of water for use in the heat exchanger. This ensures that the internal circulating water is kept completely separate from the process water.

Following the success of the project, Cool-Therm is working with Aquabio on a water reclamation plant for a food manufacturing facility in Scotland. Because this is on a smaller scale, it is likely that the chiller will be based on an inverter-driven screw compressor.