We are a leading name in this domain engaged in manufacturing and supplying a broad array of Rotary Vacuum Filter. Offered Rotary Vacuum Filters are manufactured by making use of the quality-assured raw material, sourced from the most prestigious vendors of the industry. Fabricated by the professionals by using advanced technology, these filters are primarily used in sugar industry for filtration of muddy juice.
The filter is composed of a hollow drum rotating about a horizontal axis and partly submerged in the liquid to be filtered. The periphery of the drum serves as the filtering surface; it is divided into numbers of independent section. Each of the section is connected individually to vacuum system by a small metal pipe terminating in a distributing valve suited at one end of the drum and carrying three different sectors:
One without connecting to the vacuum, but connected to the atmosphere.
The second communicating with a chamber where a low vacuum in maintained.
The third connecting to a chamber where a higher vacuum is maintained.
The exterior surface of the drum consists of a sheet of stainless steel with very fine perforation, covering all section of the drum
As the Vacuum Filter rotates, the section which first enters the liquid is immediately connected with the low vacuum. This produces an aspiration of the liquid, which passes through the fine perforations. However, the latter soon become coated with pieces of fine bagasse and suspended matter. The first juice which passes through is thus obviously badly filtered and very turbid is called “cloudy filtrate” and is directed to a special receiver.
Having now been coated with a thin layer, which is form in the beginning of filter cake. The section next passes to the valve sector connecting to the higher vacuum. It is indeed necessary to increase the vacuum, since the resistance offered by the cake increases with its thickness. However, the juice which now passes through is more effectively filtered by its own impurities and by the fine bagasse which it contains, which thus themselves from the necessary filtering surface and which collect on the surface of the drum. This filtrate then constitutes the “clear filtrate”, and is sent to another receiver. The filter cake continues to build up, until the section concerned emerges from the liquid. The juice picked up at the surface flows back into the tank, while the juice contained in the body of the cake which has formed continues to be drawn through into the compartment of the drum.
The filter section then passes under several rows of atomizers which spray hot water on the cake. This is the beginning of the washing. The vacuum draws the water through slowly. This washing has been designed in such a way that the water has just sufficient time, on the fraction of the rotation remaining, to pass through the cake and to displace the juice.
After the washing and just before the section re-enters the liquid in the tank, it arrives at a scraper formed by a rigid strip of rubber belting which bears lightly on the stainless screen. When the filter section is about to reach the scraper the distributer valve break the vacuum which has held the cake against the filter surface. Then the slight contact of the scraper detaches the cake and it drops into a screw or belt conveyor which removes it outside the building. The entire process is continuous operation, does not require much manpower.
Longer service life