Vacuum belt filters, all-rounders for filtration and dewatering
Using a Leiblein vacuum belt filter for recycling wash/process water offers the advantage that pure mechanical cleaning often involves no chemical change in the medium. Compared to a hydrostatic system, this type of filter, with its vacuum assistance, is better at dewatering the filter cake and even achieves higher throughput rates. Such filters are already in service in the minerals industry for dewatering effluent or sludge with mineral contents.
The filter’s continuous belt has stainless steel fabric or, if so desired, plastic, and operates on an inclined plane. In the lower part, the wastewater spreads out over the full width of the belt, while dewatering takes place in the upper section. The filter belt holds back the entrained particles, gradually building up a filter cake. As the resistance to flow increases, the water level of the medium also rises, eventually reaching the point at which an integrated float switch is triggered. The belt with the filter cake is then pulled upward, and the sediment carpet stripped off under the influence of a moderate negative pressure that keeps it stable. The partial vacuum is generated by a built-in side-channel compressor that continuously aspirates air out of the filter chamber. The filter cake collects in a sludge tank. A rotary brush and a flushing mechanism clean the stainless steel belt, which continues on to again dip into the wastewater. Since no filter cake is present, the water flows off more quickly, the water level recedes, and the belt stops.
The vacuum-assisted inclined-plane design principle ensures both good dewatering of the filter cake and heightened throughput. Thanks to its stainless-steel fabric, the belt is very long-lived, even with exposure to aggressive media. Scraping the filter cake off of the belt renders the use of consumables superfluous. The filter requires little maintenance, because there are hardly any wear parts. Since the filter operates automatically, there is no need for operator intervention or supervision. In comparison with belt- and chamber-filter presses/decanters, this vacuum belt filter stands as an attractive alternative in many respects, including its investment and operating costs.
//www.leiblein.de" target="_blank" >www.leiblein.de:www.leiblein.de