Vacuum filter / Negative-pressure filter

Suction belt filter SAFI-E (endless belt)

The high-performance SAFI-E filter in endless belt design achieves flow rates of up to 3000 litres per minute. Due to the modular design, higher flow rates can be achieved. In addition to its use as a stand-alone filter, it is also used to supply machine groups.

Their advantages

  • Vacuum filter for medium volume flows
  • Correct separation of dirty/clean side
  • No consumables

Short info

  • Compressed dirt cake, dry, stab-proof
  • 10 different sizes
  • Energy-optimised by FU control
  • Hybrid system (operation also possible with fleece)

Robust, durable and highly efficient

Robustness and durability are the outstanding features of this filter. Especially for central systems, its qualities such as reliability are enormously important. The filter has a special drying unit due to the exhauster, thus very dry filter cakes can be produced. Very fine filtration levels can be achieved by using different endless belts.
By using frequency-controlled components, the energy requirement is matched perfectly to the system output.


The filter housing consists of a high-quality welded steel or stainless steel construction. A transport chain carries the endless belt through the filter bed. An exhauster generates the negative pressure in the vacuum chamber and thus significantly increases the flow rate per square feet (square metre) of filter surface. The cleaned cooling lubricant enters the clean chamber from where it is discharged into the clean tank by means of a pump. The functions, triggered by float switches, are controlled by a control box.


The medium is fed to the filter by the inlet distributor, flows through the filter medium and reaches the vacuum chamber cleaned. The filter discharge pump sucks the medium out of the vacuum chamber and conveys it into the clean tank.

The exhauster creates a negative pressure in the vacuum chamber. This negative pressure supports the flow rate considerably and results in a better utilisation of the filter medium due to a higher dirt cake build-up. The built-up filter cake provides an additional, high-quality filter layer and thus improves the degree of filtration.

The pressure gradient between the clean and dirty side, caused by the exhauster, is dimensioned in such a way that the finest particles are washed up but not pulled through. The dirt particles are deposited on the filter aid and reduce the flow more and more.

The level rises on the dirt side of the filter. At a preset level, there is a belt stroke (approx. 50 mm long). The filter cake emerging from the liquid is exposed to the suction effect of the exhauster and is well dried out, additionally supported by the exhaust air of the exhauster.

The dirt is brushed off and dropped into the dirt box. The endless belt is subsequently rinsed clean with purified medium.

The filter process is not interrupted during continued cycling, an additional buffer tank is not necessary!

The built-up filter cake is a valuable filter aid and significantly improves the degree of purity. Due to the short stroke steps, this “precoat medium” is almost completely preserved and the degree of purity remains unchanged.

Precise sealing

Made in Germany

Variety of materials

Process safety

No consumables

Picture gallery

Data sheet

Standard sizesSAFI-E0.8 ESAFI-E1.3 ESAFI-E1.5 ESAFI-E1.7 ESAFI-E2.1 ESAFI-E2.5 ESAFI-E3.1 ESAFI-E3.6 ESAFI-E4.1 E
Mounting dimesion L x W1250 x 11401750 x 11402000 x 11402250 x 11402750 x 11403250 x 11403850 x 11404500 x 11405000 x 1140
Height 175017501750175017502000200020002000
Weight approx. (kg)116013101390146016101840201022102350
Volume approx. (litres) 34561575089011601435176021152385
Flow rate max. (l/min) emulsions*350770930108013601650207524202775

*Definition of flow rate: Emulsions and aqueous media approx. 1 mm²/sec at 20 °C and oils up to 15 mm²/sec at 20 °C.
The maximum flow rate of the filter is indicated; depending on the machining process and the degree of contamination, the flow rate may be lower.

Subject to technical changes in the interest of progress.

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