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Operation & maintenance manual, Discfilter HSF2200-1/2F PFC
7.4.2 Chemical cleaning of filter panels
Long-term clogging of the filter media can be caused by iron, calcium, organic growth or other
particulate matter. This clogging can normally be removed through chemical cleaning. Three pro-
ducts that have been proven not to affect the life of the filter medium are diluted hydrochloric
acid (HCl), diluted sodium hypochlorite (NaClO) and diluted sodium hydroxide (NaOH).
Use of other types of cleaning agents can cause damage to the equipment.
The cleaning products must not be mixed. If, for example, HCl and NaClO are mixed this
produces toxic chlorine gas. HCl and NaOH are highly corrosive. For safety advice, see app-
licable local regulations.
For more detailed instructions, please contact your supplier.
The standard version of the Hydrotech Disc filter in the HSF2200 series is fitted with a chemical
ramp to enable removal of long-term clogging of the filter media.
The Hydrotech chemical trolley HCT (optional) is connected to the chemical ramp connection
(see Figure 3.2 and Figure 3.5). The control system is prepared and programmed for connection
of a dosage system. After completing electrical and mechanical connection, chemical cleaning is
started as follows:
1. Turn the operating mode switch to AUTO mode (see Figure 5.1).
2. Set the number of cleaning sequences with the CLEANING SEQUENCE selector (see Figure 5.1).
3. Start chemical cleaning with the CLEANING START switch (see Figure 5.1).
Once cleaning is completed the filter automatically returns to normal operation in AUTO mode.
If necessary clean the chemical ramp’s nozzles as set out below:
1. Remove the nozzle by turning it ¼ turn antic-
lockwise (see Figure 7.10).
2. Clean the nozzle with compressed air or a
plastic brush. Never use a wire brush, metal
rods or similar as these can damage the nozzle.
3. Refit the nozzle.
Figure 7.10 Nozzles on chemical ramp.