Cedar Meats implements wastewater solution

Cedar Meats needed to upgrade its DAF system but didn’t want just the ‘standard’ system. It wanted a more energy-efficient system, and one that could deliver low running costs for the life of the system.

The ‘conventional’ DAF system consists of a centrifugal pump that pulls clean effluent from the DAF tank and feeds it into a pressurised air saturation vessel. A compressor also feeds compressed air into the same vessel and the air saturates into the effluent water under pressure. The water is then fed back into the bottom of the DAF tank where the air comes out of solution (because of the lower pressure) to form tiny microbubbles, which attach to fats and grease in the system and float it to the top of the tank where it is scraped away. The system requires a control system to combine air and water needs, and it requires regular certification of the pressure vessel.

The Chief Engineer at Cedar Meats, Yogesh Mistry, went looking for a solution that didn’t involve intricate and delicate control systems and didn’t need ongoing Worksafe certification for pressure vessels. He contacted Hydro Innovations to get information on the EDUR DAF pump.

Solution

German Pump manufacturer EDUR has developed a multi-stage multiphase pump capable of handling a gas/water mixture, making it suitable as a DAF pump. The pump draws clean effluent from the DAF tank and, at the same time, draws in atmospheric air on the suction side of the pump. The pump sheers and mixes the air with the water and, under pressure from the multi-stage pump, air saturates into the effluent water. The water is then pumped into the bottom of the tank, where the air comes out of solution, as in conventional systems. No compressor or air saturation pressure vessel is needed.

Mistry was impressed with the simplicity of the system and purchased the EDUR DAF pump. He has been pleased with the positive results, which included:

• higher rate of solids removed
• less power used for the job (reducing power costs)
• less complicated controls
• low maintenance.

The EDUR multiphase range of pumps is available with flow rates from 0.5 to 15 L/s to enable them to handle a wide range of DAF plant in-flows. Pumps are constructed of either C.I./Bz/SS, nodular cast iron, all bronze, all stainless steel or all Super-Duplex stainless steel construction, so may be used to handle a variety of liquids. Air, oxygen, carbon dioxide and ozone gases can be introduced into the suction line and transported and used to mix or disperse the gases.

According to Hydro Innovations, the advantages of the EDUR DAF pump over conventional systems include: a reduction in system components; smaller footprint: reduced energy consumption; reduced maintenance costs; reduced noise levels; improved WHS; simplified system operation; and optimum microbubble size for good rising speed.