Cooling Water Filtration
AUTOMATIC SCREEN FILTER
An automatic screen filter, also known as a self-cleaning screen filter, is a type of filtering system that uses system
pressure to clean itself.
M100-750 for up to 40m3/hour.
M100-1500 for up to 80m3/hour.
M100-4500 for up to 180m3/hour.
M100-6800 for up to 400m3/hour.
Cooling water enters the filter through an inlet, then passes through a rigid cylindrical screen from the inside out,
causing particles larger than the openings of the screen to accumulate on the inside surface and form a filter cake.
Filtered water leaves the filter body through the outlet. The build-up of the filter cake in the upstream side of the
screen causes a difference in pressure between the inlet and outlet of the filter.
A controller monitors the pressure in the filter and opens a flush valve when it senses a differential pressure threshold
has been exceeded. When the flush valve opens to atmosphere, the difference between the higher pressure of water inside
the filter and the atmosphere outside the filter body causes high suction forces at the openings of each of the suction
scanner nozzles. The suction force causes water to flow backward through the screen in a small area at very high velocity
at each nozzle, pulling the filter cake off the screen and forcing it into the suction scanner and out the exhaust valve
Fully automatic self-cleaning screen filters provide an economical means of removing suspended
solids down to 10 microns from cooling tower water. The use of weave-wire screens as the
filtering media provides a positive removal system eliminating all particles larger than the
filtration degree of the screen from the cooling system. The efficient suction scanning principle
allows the filter cake to be removed completely from the screen surface within seconds without
physically touching the cake or screen. During the suction scanning cleaning cycle the filtration
process is uninterrupted; thereby, providing filtered water downstream of the filter at all times,
eliminating the need for duplex systems. Water and chemical losses are kept to a minimum, and
organic and inorganic solids are removed with equal efficiency.
Automatic self-cleaning screen filters lend themselves to many industrial, commercial and power generation
cooling tower applications.