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V-Series™ Filter: How It Works

Dirty water enters the filter through the inlet (1) and then passes through the coarse screen (2) from the outside in. It flows from the inside of the coarse screen to the inside of the fine screen and then passes through the fine screen (3) from the inside out. Dirt is collected on the inside surface of the fine screen. The clean filtered water then exits through the filter outlet (4) and on to the system.

As the dirt or cake builds up on the inside surface of the fine screen, the pressure drop across the screen increases. When the pressure drop (the DP or differential pressure) reaches a preset level of 0.5 bar (7 psi), the filter controller starts a flush cycle by opening a flush valve on the flush outlet (5). This flush valve exhausts the drive chamber to atmosphere at “0” psi.

The flush outlet is connected to the flush chamber which is separated from the filtration chamber by a lower bulkhead (6). However, the dirt collector (7) (a hollow pipe with suction nozzles) extends through the partition, thus providing a “path” from the suction nozzles (8) through the water motor (9), into the flush chamber and out the flush outlet to atmosphere. The pressure around the suction nozzle is the pressure inside the filter and as water flows through the “nozzle orifice,” it drops to “0” psi when it leaves the flush outlet. This creates an aggressive “suction” at the suction nozzle opening. The suction nozzle clearance at the fine screen is very small so the extreme low pressure at the nozzle opening creates a vacuum causing backflow to pull the dirt from the fine screen.

The water motor has opposite facing jets near its ends. Water jetting out of these openings (coming from the suction nozzles) creates a reaction force (like a pin wheel) which rotates the motor and the dirt collector. As the dirt collector rotates, each suction nozzle cleans a band on the fine screen. As the dirt collector rotates, the reverser (10) (works like the level winder on a fishing reel) causes the water motor / dirt collector / suction nozzle assembly to move back and forth on a controlled path.  This ensures proper overlap for 100% cleaning of the screen's inner surface.

The rotation governor (11) helps control the rotation speed of the dirt collector assembly. The balance tube (12) helps balance the transverse pressure on the assembly.  A magnet located on the end of the balance tube repels the reverser indicator (13) which provides visual indication of the dirt collector assembly movement.  This indicates that that the entire cleaning system is operating properly during the rinse cycle.

After a preset time, the flush valve closes and the flushing cycle is complete. Minimal water is used for each flush, and the filter continues to supply water to the system during the flush cycle.