Mechanical separation equipment centrifuges

The suspended droplets of liquid monomer are progressively converted to solid or porous PVC particles. Unreacted VCM is stripped from the polymer and water is separated by centrifuging. The polymer is then dried, typically in fluidised bed drying equipment. Prior to start-up of the next polymerisation cycle, the reactor is cleaned and coated with an antifouling agent. The mechanism of action of antifouling agents has been studied (149). 

Centrifugation is a mechanical separation technique, which accelerates the phenomenon of sedimentation through the imposition of rotational motion in a liquid/particle suspension. In the centrifugation equipment, the centrifugal force causes the particles to move radially away from the axis of rotation, as shown in Figure 2.6. 

Although the spiral concentrator is mechanically a veiy simple piece of equipment, the separating ac tion taking place is complex. It involves centrifugal force, rric tion against the spiral surface, gravity, and the drag of the water. 

Crystallization from solution is a widely utilized separation and purification technique in chemical industry. It is characterized by the formation of a spectrum of differently sized crystals. This spectrum, called the Crystal Size Distribution or CSD, is highly important for the performance of the crystallizer, the crystal handling equipment like centrifuges and dryers, and the marketability of the produced crystals. However, in many industrial crystallizers, the observed CSD s show large transients due to disturbances or are unstable because of the internal feedback mechanisms of the crystallization process ). The main limitation for effective CSD control was the lack of a good on-line CSD measurement device, but recent developments show that this hurdle is taken (2). 

Clarifier equipment for removing the color or cloudiness of an oil or water by separating the foreign material through mechanical or chemical means may involve centrifugal action, filtration, heating, or treatment with acid or alkali. 

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