Belt filters – DOPFA series

  • For applications with both ferrous particles and non-ferrous particles
  • The filter paper automatically advances when contaminants accumulate.
  • The effectiveness of filtration depends on the accuracy of the filter paper chosen
  • Filter degrees: multiple options


Belt filters are designed to filter many types of liquid independent of the degree of contamination, thickness of the liquid (viscosity) and the quantity offered (the flow rate).

  • Capacity: from 20 l/min to 500 l/min
  • Tank volume: from 100 l to 980 l
  • Motor: 25W / 40W / 60W
  • Filter paper: B: 500mm / 700mm / 1000mm


Fleece bed filters have a filter fleece that serves as the filter medium. This filter fleece is on a roll of up to 250 m in length. Automatically, clean filter fleece is retrieved in the plant and the contaminated fleece is transported in a container tray. The filter rolls, available in various filtration degrees, are less expensive per m² compared to other filter media. With average contamination, you only need to change a 300 m filter roll once every 3 months. The contamination which is filtered out of the liquid works in itself as an extra filter (pre-coat effect) so that very high filtration degrees can be achieved.


The automatic belt filter system is based on gravity filtration. The water flow containing contaminants (1) is directed through the inlet distributor (2) onto the endless conveyor (3) with filter fleece (8). Solids larger than x microns in size are retained by the filter membrane. The cleaned water stream passes through the filter belt into the buffer tank (4). As the filtered material increases, a so-called filter cake, the concentrate, forms (5). During this process, the filter belt becomes increasingly less accessible to the contaminated water stream. As a result, the water level in the contaminated water basin rises (6). The elevation of the water level can be measured by a level probe (7) or a mechanical float. At a pre-calculated position, the conveyor motor is set in motion. The band stops when the level in the basin has dropped again. The accumulated contaminants together with the filter fleece are collected by the forward motion of the conveyor belt in a container set up for this purpose.

How a band filter works

1. dirty liquid inlet
2. inlet distributor
3. conveyor belt
4. buffer tank
5. concentrate
6. contaminated liquid reservoir
7. level switch
8. filter fleece
9. collection container for concentrate


Paper belt filters (DOPFA series) have been used for many years in many different applications. Due to the high filtration rate, autonomous operation and low operating costs, paper belt filters have already been installed within a large number of workshops. The buildup of contaminants on the filter membrane, better known as “filter cake,” will increase the final filter accuracy.

The paper belt filters are mainly used in machine tools where aluminum and cast iron are machined. The belt filter is also frequently used in grinding to obtain an optimum surface roughness (RA) in this way.


The paper belt filters are available in nine different capacities. Customer specific requirements also possible. Within this DOPFA series there is always a paper belt filter applicable for your lathe, milling machine and/or grinding machine. Can also be used for broader applications such as cooling water filtration, wastewater, … Our representatives can help you choose the right paper belt filter.

Technical specifications

Technical data paper belt filter DOPFA series