Boll & Kirch duplex filter
The filter concerned was a Boll & Kirch duplex filter, 2.05.5DN250; a type of filter with one filter chamber in use and another filter chamber on standby. In the event of contamination, the filter chamber can be switched by simply pulling a lever. This immediately ‘blocks’ the contaminated element in the relevant filter chamber so that it can be dismantled for ultrasonic cleaning. A big advantage for customers is that there is no interruption to the water supply and discharge, and the filter remains functional continuously.
The filter housing is equipped with a special internal coating and the other parts are nickel-plated or have a rubber coating. This protects against the canal water’s relatively aggressive physical and chemical properties. The Boll & Kirch filter has an optical/electrical differential pressure gauge, making the extent of contamination visible immediately.