The rubber belt filter of type BFR is a continuously operating, horizontal vacuum filter used for the reliable separation of quickly sedimenting solids from suspensions. It is characterized by high throughput rates and a robust design. Cake treatment involving one or more washing stages is possible.
ERZ Entsorgung + Recycling Zurich produces 5,000 tons of fly ash per year, which is continuously washed out. To efficiently separate the fly ash suspension from the washing water, ERZ is using the fully automatic, heavy-duty rubber belt filter (BFR) from BHS-Sonthofen.
The BHS rubber belt filter stand out thanks to its robust construction that specifically addresses typical applications. A firm supporting structure made of steel or stainless steel allows this system to be used even in harsh environments. BHS rubber belt filters are designed for a long service life under heavy load. This minimizes both maintenance and operating costs.
Due to the small number of individual parts installed, a rubber belt support in the form of a roller table and optimum accessibility to the vacuum box, the rubber belt filter is extremely resistant to wear and easy to service. Robust systems for belt support and belt guidance result in a long service life and reduced maintenance times.
BHS rubber belt filters are designed to deliver top filtration performance. Depending on the application, suspension capacities of up to 15 m³/m²/h can be achieved. Downstream cake processing, such as one- or multi-stage cake washing, is also possible on demand. Filter surfaces can be dimensioned up to 162 m² per filter.
By using tried and tested measuring and control equipment to measure cake thickness and belt speed, the filter can be flexibly adapted to the respective requirements in terms of production output. Downtimes due to retrofitting or adaptation are eliminated.
Various materials are available for the design of the carrying belt, the supporting structure and attachments. Given the large selection of plastics for the filter cloth and vacuum box, the rubber belt filter can be used in a wide range of applications. Accessories such as a vacuum station or blower, filtrate or pre-thickening station enable the filter to be designed as a complete system perfectly adapted to the respective application.
A circulating filter cloth, which is continuously moved, serves as the filter medium. A rubber support belt is used to support the filter medium. The belt features milled grooves for filtrate discharge. It moves over a stationary vacuum box on a roller conveyor as well as on wear and sealing belts. The box collects and discharges the filtrates.
The filter cake builds up on the membrane. This can be further treated by washing out (possibly several times in a counter-current), steaming, extraction or dry suction. The filtrates can be acquired individually by each process stage and processed without any intermixing. The take-off roller is where the rubber belt filter ejects the cake. A mechanical scraper system can be integrated for additional support. The membrane is cleaned in the lower part of the filer when the conveyor belt is reversed.
The design with roller support of the carrying belt results in considerable water savings and at the same time increases the system’s reliability compared to conventional designs.
Use of the roller table eliminates the need to consume operating media such as compressed air or water. Tried and tested roller systems support and guide the rubber belt. This system offers high reliability and is easy to maintain.
The vacuum box is located underneath the filter. It is used to apply a vacuum to the rubber belt and thus to the filter cloth. Wear belts with a sealing water supply system reliably seal off the production space from the atmosphere. The vacuum box is delivered in plastic or stainless steel. Easy accessibility and low sealing water consumption are guaranteed.
Active filter width
Active filter length
Active filter area
|BFR 120||1.050 mm||6 - 10 m||6 - 11 m²||up to 11 kW||9,5 - 13,5 m||2,2 m||2,3 m||3 - 10 t|
|BFR 160||1.450 mm||8 - 14 m||12 - 20 m²||up to 15 kW||11,5 - 17,5 m||2,6 m||2,3 m||4 - 15 t|
|BFR 200||1.850 mm||10 - 18 m||18 - 33 m²||up to 18,5 kW||13,5 - 21,5 m||3 m||2,3 m||6 - 20 t|
|Operating temperature||up to 90 °C|
|Solids content (suspension)||up to 60 % (by weight)|
|Cake thickness||up to 80 mm|
|Grain size||10 - 500 µm|
|Filter output – suspension||up to 15 m³/m²/h|
|Filter output – dry solids||up to 5.000 kg/m²/h|
|Active filter surface||6 - 33 m²|