FOWARD CLEANERS e-mail print Specifically COMER Low Density Cleaners are for removing the smaller impurities from the stock, like sand, clay, stickies still present in the stock which have a higher specific gravity compared to the pulp fibres. They operate at a consistency of between 0,5 and 1,2% and treat all kinds of stock. The material, Polyurethane of a special formulation and exclusive to COMER, is used to manufacture the cleaners as it has an array of advantages. Its strong resistance to abrasion, chemicals, high temperatures and mechanical wear is all-important for a production unit. The number of cleaners and stages to be used will depend proportionally on the cleaning degree required and the quality of furnishes being demanded. It is common to have three or four stages and for them to be installed in a vertical bank. COMER thin stock cleaners are available in two sizes handling respectively 120 (32 US gpm) and 650/700 litres per minute (170/180 US gpm). The 120 litre cleaners are recommended for deinking plants, due to their higher efficiency for removing heavy ink particles.OperationThe suspended fibre enters the cleaner by a tangential inlet. This increases the speed of flow and creates a rotary movement inside the cleaner.The geometry of the cleaner and the specially designed inlet head generates a high centrifugal force. This force causes the pulp to be thrown against the cleaner wall and to join the rapidly rotating inner vortex at the cleaner's core. This movement forces the suspended fibres up through the accepts orifice and the impurities, due to their weight, down and out of the rejects orifice into the reject manifold. The reject orifice is obstruction free to prevent any plugging and slime or bacterial growth.FeaturesThe reject nozzle is a separate component, which can be changed without having to remove the whole cleaner. This keeps maintenance costs down and the job is accomplished a lot quicker. A balance is achieved between the cleaners in the bank, to constantly deliver the same amount of rejects. By creating the balance, variations in temperature or consistency in stock, the cleaners are insensitive to changes. The cleaning efficiencies are not seriously affected if the inlet and outlet pressures are wrongly set. A low-pressure drop created by the movement in the cleaner has a significant hearing on the cost of pumping power.