GRAVITY FILTERS
Model HGF
Model DBGF
Model LGF
Model LF (Li'l Fil)

AIR VACUUM FILTERS
Model SCF
Model HVSCF
Model FLA

LIQUID VACUUM 
FILTERS
Model LVF

PRESSURE FILTERS
Model APF

SLUDGE FILTERS
Model SF

ABSORPTION FILTERS
Model ABS

MAGNETIC 
SEPARATORS
Model MSI
Model MSI Video

CENTRIFUGES
Model ACF
Model ASF
Model MCF

EVAPORATORS
Model TEB

VACUUM 
DISTILLATION UNIT
Model VDU
Model VDU Video

OIL-WATER 
SEPARATION
Model OWS
Model DTOS

AUXILIARY
EQUIPMENT
Model SMR
Model SDU

ALUMINUM ROLLING AND DRAWING
Cold Rolling Coolants
Aluminum Wire Drawing

METAL GRINDING
Roll Grinding Coolants
Centerless Grinding
Parts Grinding Coolants

INDUSTRIAL 
WASTEWATER
Spent Coolants
Process Wastewaters

MACHINING
Machining Coolants
Honing Coolants
Gun Drilling Coolants

METAL FINISHING
Alkaline Cleaners
Acid Pickling Solutions
Electroplating Rinsewater

PAINT SLUDGE
Paint Sludge Dewatering

PHOSPHATING
Sodium Phosphate Solns
Iron Phosphate Solutions

STEEL ROLLING
Cold Rolling Coolants
Stainless Steel Rolling Oils

WIRE DRAWING
(NON-FERROUS)
Continuous Cast
Wire Drawing Emulsions
Annealer Quenchants
Spent Emulsion Disposal

WIRE DRAWING
(FERROUS)
Wire Drawing Emulsions
SST Drawing Oils
Annealer Quenchants
Dry Soap Rinsewaters

In a variety of industrial processes, there are extremely fine particles generated that may affect tooling wear and product quality. These particles are often difficult to remove through gravity and vacuum filtration due to the dense filter media required to remove the particle.

The Filtertech Automatic Pressure Filter Model APF is designed specifically for this type of application by creating an extremely large pressure differential across the filter media.

Mode of Operation

The Model APF Automatic Pressure Filter is fed with dirty solution by an optional feed pump from the dirty sump or reservoir tank. An automatic three-way valve is used to control the flow of solution to the inlet manifold of the filter, which only lets solution into the filter chamber during the filtration cycle (fig. 1). Inside the filter chamber a perforated platen supports the filter media which removes the solids and allows only clean liquid to pass through. The clean solution then exits through the discharge manifold to a clean reservoir for reuse. The filter chamber is sealed at both ends by either a pneumatic or hydraulically-operated set of doors to prevent dirty liquid from exiting out the ends of the chamber.

FIGURE 1
FILTRATION CYCLE

As the solids build up on the surface of the media, a filter cake is formed. This cake helps to further improve clarity through depth filtration in which the cake acts as the filtering media removing even smaller particulates. Over time the filtrate rate decreases causing the pressure inside the chamber to increase.

When sufficient pressure has been generated, the air blowdown cycle is initiated and the feed to the filter is diverted by the automatic three-way valve back to the dirty reservoir tank (fig. 2). The remaining liquid in the filter is evacuated by pressurizing the chamber with compressed air and forcing the liquid through the filter media.

FIGURE 2
BLOWDOWN CYCLE

After the liquid has been removed from the filter chamber, the indexing cycling is initiated and the chamber doors which are pneumatic or hydraulically- operated are opened (fig. 3). The automatic media rewinder then advances the dirty filter media out of the chamber where the filter cake is separated and discharged into a collection hopper while the spent media is rewound for disposal. On permanent media models, the filter media is passed through a cleaning station before being rewound for reuse. Once the entire length of spent media has been advanced out of the filter chamber, the doors are then closed and solution flow to the filter is resumed.

FIGURE 3
INDEXING CYCLE

For more information request Product Bulletin FT219A or download PDF file.

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