HOFFMANN pressure belt filters are used in the machine tool industry for cleaning coolants and in the wastewater sector for filtering wastewater, just to name a few of the many applications.

Our HKF and DBF pressure belt filters are manufactured of painted steel, galvanized, or stainless steel. These types of filters operated automatically and can also be used as precoat filters.

Method of operation

1.	Incoming impurities	5.	Flushing unit
2.	Top chamber	6.	Continuous plastic belt
3.	Bottom chamber	7.	Peeling roll
4.	Discharge of cleansed material	8.	Sludge discharge

Soiled medium is transported from the processing machine into the fouled tank section of the HOFFMANN pressure belt filter. A filter pump accommodates the soiled fluid and routes it into the sealed, closed filter chamber (space between the top chamber and the continuous plastic belt) of the pressure belt filter. The fluid flows through the filter belt and the particles of impurities are trapped on the filter belt, where they form the filter cake. The cleansed fluid is routed to the clean tank section. Machine supply pumps transport the cleansed fluid back to the processing machine.

As the level of impurities (filter cake) rises on the filter belt, the differential pressure in the filter chamber increases. The regeneration process is initiated when the maximum differential pressure is reached, or after a defined time. The fluid inlet is closed and the filter cake blown dry using compressed air. After that, the filter chamber opens automatically and the filter cake is moved out of the chamber on the continuous filter belt and falls into a sludge box.

Upon request, or if required, the cleansed medium is also moderated using a HOFFMANN chilling unit in accordance with plant-specific requirements.

Advantages:

• very high throughput volume
• easy, local or central installation
• filtration without the use of filtration aids
• fully automatic, maintenance-friendly operation
• continuous supply of your loads with cleansed medium
• good filter cake build-up thanks to high differential pressure
• high level of cleansing
• can be used for fine and clear filtration as a precoat filter with apportionment of filtration aids
• high level of process reliability

Important:

Opening and closing of the HOFFMANN HKF-type pressure belt filters is performed by two pneumatic cylinders. These cylinders also keep the pressure belt filter closed leak-tight on a loss of pressure.

Depending on the task at hand, the following options are available for filtration:

• continuous plastic belt
• continuous plastic belt, coated with filtration aids (e.g. cellulose) via a precoat system
• filter paper