Endless Belt Compact Filter

Firma Stevens-Hydrobelt endless belt filters are available in standard range for filter handling capacities up to 2000 I/min. Installations for higher flows on request.

For cleaning coolant lubricant emulsions or other polluted liquids. The filter handling capacity indicated applies to fluids with a viscosity up to 6 mm2/s. When using this filter with filtrates with higher viscosities (maximum permissible is 45 mm2/s) consultation with us is necessary, as the specific filter area must be correspondingly larger.

Main fields of application
Firma Stevens-Hydrobelt endless belt filters are used for cleaning coolant lubricant emulsions and cutting oils, used in metal processing operations on machine tools.


  • The endless belt filter is characterized by its use of an endless synthetic filter belt which results in zero filter aid consumption.
  • Lower discharge casts because there is no problem as to the discharge of the filter belt and hereby the dirt volume is reduced considerably.
  • Lower casts of maintenance, no control, no replacement of filter belt.
  • The compact filter reaches the same coolant flow as the gravity filter with a substantial smaller filter surface.
  • The filterfineness of the compact filter is better, as the filter cake condenses more, because of the higher liquid level.
  • No magnetic separator required.


The endless belt filter is a further development of the gravity filters, but doesn't use filter material. The filter bed with the endless belt filter running around it, is installed obliquely (mounting to the discharge ramp) in the filter tank. Due to the shape of the filter tank there is a higher liquid level on the filter material compared to the conventional belt filter. Because of this the liquid pressure on the filter material is twice as high. The result is a higher filter performance.


The endless filter belt lays on top of the filter tank (V-shape). On both sides of the filter belt, transport chains are foreseen with a fastening of the belt in the neutral line of the chain, so with the turnover no relative movement between filter belt and chain is possible.

The medium to be cleaned is introduced into the filter chamber. From there the medium, cleaned by the filter material, flows into the coolant container underneath the filter chamber.

With the increasing contamination of the filter belt and the gradual building up of the filter cake, the filter material becomes impermeable, resulting in a rise of the fluid level in the filter chamber. When a predefined maximum fluid level is reached, the filter material transport is switched on by means of a float-operated switch. Thus uncontaminated filter strip reaches the filter bed and the fluid level decreases again.

The retained dirt is removed by means of a scraper and falls into a container.

On the side where the filter material enters the filter chamber, a cleaning mechanism above the polluted fluid is installed in such a way that the washed dirt is automatically led into the filter chamber. This fine dirt is filtered by the filter cake. The cleaning process will be activated after the belt transport, so the cleaning is totally independent of the material velocity. The cleaning installation is patented and consists of movable nozzles and a pump.

The automatic drive for belt transport and belt cleaning is included.

The nominal filter fineness of the used standard synthetic belt is 30 µm approximately. Because of the thicker filter cake, the filter fineness improves.
The endless belt filter is normally built on a coolant tank, of which the dimensions can be chosen. A standard container program is deliverable. A coolant pump can be installed for the users.

The installation of more coolant pumps is possible (as well for users with various pressure levels).

  1. Inlet chute
  2. Cleaning unit
  3. Guide pulley
  4. Cleaning motor
  5. Outlet channels
  6. Endless filter belt
  7. Scrapers
  8. Drive
  9. Float switch
  10. Outlet chute
  11. Drive motor
  12. Electrical connection box Coolant lubricant tank
  13. Waste container
  14. Coolant lubricant pump
  15. Belt cleaning pump