Equipment designed and built to remove all non-emulsified oils of the contaminated water, producing an effluent with a charge of less than 10 mg/lt of oils, for a drop of 20 microns or greater. Separation process is automatic and incorporates the use of inclined sinusoidal coalescing plates, arranged in such a way as to lead the oil drops to gather on the surface. Similarly, inclined plates facilitate sedimentation of solids contained in the treated flow without clogging or blockages. These solids settle in a hopper provided for this purpose. The separator is designed to retain the recovered oil without leakages, and it is suitable to process wide variations of flow and oil contents.
Coalescers are made of plastic or carbon steel. They are installed in the effluent pre-treatment phase, usually after a screen or main grid. In certain cases it is previously expected the dosage of an emulsifier breaker to remove also the oils emulsified in the effluent.
In order to facilitate oils removal the effluent goes through an oleophilic PVC fill with a large contact surface made of a plastic with a great affinity with oils. The basis for this option lies on the properties of certain materials, especially plastics, which once put in the contaminated water flow it increases the efficiency of oil removal when its surface is covered with it. As the flow passes, small oil particles soak the plastic as they are attracted to its surface, attaching to it. Other drops are also attracted by the surface and they gather “coalesce” with the previous ones, increasing their size until they come loose and go up to the surface where they are removed from the equipment.
It is important to note that when free fat content is big a clogging of the coalescer unit may occur, and the equipment should be put out of operation to be cleaned. In such cases it is recommended the installation of a DAF unit which are more effective (slaughterhouses, dairy industries, sausages and cold cuts among others).