Electric Automatic Backflush Side Stream Filter, Brand Name : Stf

Working Principle:-

Pressurized water enters the filter Inlet (1) and travels through Fine Screen (2)where suspended particles are filtered. Clean water then exits the filter through Outlet (12). As particles deposit on the screen, pressure drop across the screen increases, and is continuously sensed by Differential Pressure Indicator (10). When it reaches 0.5 bar, the Electric Control Unit (3) triggers the Solenoid Valve (11) to open the Hydraulic Flushing Valve (4) and the upper, Hydraulic Motor Chamber (6) gets exposed to atmospheric pressure. With the lower chamber being at line pressure, water escapes from it to the upper chamber through the Dirt Collector (7). For this, water is sucked by Suction Nozzles (8) which dislodge & suck dirt deposited on the inside surface of screen. As water passes through the Hydraulic Motor (9), it gives the suction nozzle assembly rotary motion (like sprinklers in lawn irrigation). Simultaneously the Hydraulic Piston (5) raises the suction assembly. With these two motions together, nozzles clean the whole periphery & height of the screen. The flush water flows through the dirt collector and out to the flushing valve to atmosphere. After a preset time, the flushing valve closes and the cleaning cycle is complete. Dirt collector then settles down by gravity.

The entire cleaning cycle takes approximately 15 seconds. 

Even during the back-flush cycle, filtering continues interrupted.

Benefits of Circulating Cooling Water On-line Filtration: 

Following are various effects of TSS build up in circulating cooling water.

Many of them would apply to you:

• Power consumption:

o chiller compressor power consumption goes up due to

fouling/scaling of condenser and cooling tower internals

o deposits in piping cause restriction to flow, causing more

pumping power for maintaining same flow

o reduced heat transfer efficiency in heat

exchangers/reactors/condensers necessitates increase in

cooling water flow rate, for evacuating same amount of heat,

consequently more pumping power.

• Production loss:

o Reduced throughput in reactors/process-condensers, due to

slowed down cooling

o Downtime for removal of scale from condenser/heat

exchanger/reactor and Cooling Tower internals

• Maintenance cost:

o Cost of manpower

o Cost of descaling chemicals

o Replacement of cooling tower fills & nozzles

o There are even instances of collapse of film fill assembly,

due to increased dead weight

• Water consumption:

o CoC can be increased by keeping cooling water clean from

suspended solids

• Water treatment chemicals' consumption:

o Goes up with rise in turbidity of cooling water, for maintaining

the chemicals' efficacy

• Others:

Corrosion due to scaling and bacteria finding shelter between

scale & tube surface (known as under-deposit corrosion),

reducing life of tubes

o Every time chemical descaling is done, some parent material

is eaten away, reducing life of tubes

o Increased rate of erosion of pump seals & valve seats

o Erosion also happens due to continuous bombardment of

suspended matter carrying abrasive content

o Particles may also scratch away metal-oxide or other

protective films

o Suspended matter provides surface for microbial growth, which

is carried with humid & hot discharge air. It can spread

contamination in neighborhood as heavy air descends--

causing health hazard (there have been casualties abroad

caused by this phenomenon called Legionella)

o Organic suspended matter causes growth of biofilm & slime

which also leads to corrosion and insulation of heat

exchange surfaces.

On-line Cooling Water Filter of innovative design is a small-in-cost,

big-in-benefits solution for these problems, already working in 17 states of

India.