Bulletin 1010: Bag Filters for Closed Loop Systems


Jan 11, 2016

Columbus, OH –

What does it do?: A Bag Filter removes iron and other particulate matter from closed loop system water. Chardon supplies a model called the Filter Feeder which serves as both a 5 micron filter and a shot feeder. This one convenient apparatus allows water treatment products to be easily added to the system while maintaining an extremely low level of suspended solids.

Why do I need a filter?: All closed loop systems have some iron components and many are constructed entirely of iron pipe. While Chardon’s closed loop water treatment products provide excellent protection against corrosion, many loop systems have had years of neglect. Iron corrodes without adequate treatment levels and corrodes quickly with no treatment at all. As iron slowly corrodes or dissolves, it is carried in solution throughout the system until chemical reactions allow the iron to precipitate and form iron deposits. Iron deposits can clog heat exchangers, cause or accelerate corrosion and harbor harmful bacteria.

Why can’t I just flush the system?: Flushing the closed loop system does remove iron in solution, but it also dilutes the water treatment chemicals which protect the iron surfaces. Make up water is usually saturated with oxygen which further depletes the active ingredients in the treatment product. Flushing the loop often accelerates corrosion in closed loop systems. A Filter Feeder works in conjunction with the closed loop treatment chemicals to break up, mobilize and remove iron deposits in closed loop systems.

Is there anything special I need to do?: The oxidation state of iron depends on the pH of the water. Iron forms a larger complex when the pH of the water is in the 10 – 11 range and readily sticks to the 5 micron filter in the Filter Feeder. The effectiveness of the filter can be greatly reduced if the pH of the water is below 9.0.