6” MCFM - 12000
01.2021
Page 11 of 61
DESCRIPTION AND FILTER OPERATION
Filtering process
The MCFM is an automatic, continuous, self-cleaning filter for high flow rates and high dirt loads driven by electrical
control combined with pneumatic or hydraulic operation. The MCFM is designed to work with various types of screens
in filtration degrees from 3000 to 15 micron, and is available in 4", 6", 8", 10" and 12" inlet/outlet diameters.
Self-cleaning process
The PLC controls the self-cleaning modes required according to type of dirt and dirt loads or other application variables.
The MCFM will start the self-cleaning process when the pressure differential across the screen reaches a pre-set value or
a pre-determined lapse of time. The MCFM can also run in a continuous mode.
The water flows through inlet, passing through the coarse screen. The dirt is stopped on the inner face of the cylindrical
fine screen. The filtered water flows to the outlet.
A central dirt collector is equipped with suction nozzles and injection nozzles.
A back-flush stream removes the dirt from the inner cylindrical fine screen face through the back-flush nozzles to the
drain chamber and via the flush valve. The injection stream passes through the injection nozzles and cleans the back side
of the fine screen.
While back-flushing, the collector's movement is both rotational as well as longitudinal. The combination of these
movements ensures full coverage of the screen area by suction and injection streams.
Rotational motion is achieved by an electrical drive unit. Longitudinal motion of the piston is achieved in one of two
ways:
Pneumatically (pneumatic piston)
Hydraulically (hydraulic piston—optional)
Different modes of filtration
The filtration system may be found in one of the following modes:
Triggered mode:
In this mode, the back-flush cycle is operated at pre-determined time intervals or differential
pressure inputs.
Continuous mode:
In this mode, the back-flush cycle operates continuously.
The Triggered and Continuous Modes are divided into sub-modes:
Flush sub-mode:
The flush valve, pump and piston are active. The MCFM is filtering and self-cleaning at the same
time.
Rest sub-mode:
No self-cleaning activity. The MCFM is only filtering the fluid. This sub-mode is only available in the
triggered mode.
Super-flush sub-mode:
This sub-mode of flushing is used to create a greater suction pressure than that in the triggered
and continuous modes, in order to remove stubborn particles from the fine screen which cannot be removed by the
normal flush sub-mode suction pressure. In this sub-mode, back-flush suction pressure is increased for a short period
of time.
Reduced flow sub-mode:
In this sub-mode, the MCFM outlet valve will close. This will increase the filter internal
pressure which will create a higher suction pressure. This sub-mode occurs only under high differential pressure input.