04-09-2012, 02:46 PM
Self Cleaning Filter
Construction
Back wash type self-cleaning filter is constructed of filter housings, filter elements, drain valve, auto back wash valve and PLC controller. Filter housings can be offered in
various materials of construction such as various grades of stainless steel, carbon steel and alloy metal. Filter elements can be offered with wedge wire, sintered multi-layer
wire mesh, plain wire mesh and sintered metal powder configuration. They are selected based on the requirement of filtration quality. For 100 microns and more, normally it is
recommended to use wedge wire element. From 2 microns to 100 microns, it is advisable to use sintered multi-layer wire mesh and plain wire mesh, depending upon the
application requirement. For final filtration of 0.2 microns to 5 microns, sintered metal powder is a suitable filter media. Customers can use pneumatically or electrically
operated butterfly valve or ball valve as per their process requirement. Normally our systems are equipped with pneumatically operated solenoid valves for back washing and
draining. Control panels can be offered with FLP (flame proof) and non-FLP, depending upon the process requirement.
Operation
Back wash type self cleaning filters work on a flow direction of outside to inside.
Unfiltered fluid enters into filter housing through bottom tangential inlet
connection. Contaminants are deposited on the outer surface of filter elements
and clean filtrate passes through inside diameter of element and removed
through the top tangential outlet. Users can set their differential pressure data
within control panel. Once the differential pressure across the system reaches
the pre-defined level of pressure drop, inlet and outlet valves shut down and the
drain and backwash valves open for defined interval of time. During this process,
debris deposited on outer surface of element shall be drained out and collected
through bottom drain. This cycle continues as per pre-defined settings and
process requirements.