JUMO 202755/20, Руководство по эксплуатации

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10 Operation
10.9 The dilution function
Brief
description For cooling water, the conductivity is used to deduce the total salt content. If a
conductivity limit is reached (at the maximum permissible salt content/
concentration), then the cooling water must be diluted. A dilution valve is
opened, the concentrated water flows out, and is replaced by fresh water.
When the conductivity of the cooling water has fallen below the limit, the
dilution valve is closed again.
Addition of
biocide A biocide is added to the cooling water, to prevent biological growth in the
cooling system. There is no ideal setting for the amount used and the timing of
the biocide dosing. In most cases, the dosing time is used as the controlled
variable. The dosing quantity is therefore defined by the pumping rate and
duration (system-specific). The success of the biocide treatment must be
checked at regular intervals.
Dilution before
biocide addition If a biocide that increases conductivity is added to the cooling water, this
could increase the conductivity to beyond the limit. This would cause the
dilution valve to be opened, and a portion of the added biocide would be
discharged into the waste water (possibly contravening regulations!).
To prevent this, the conductivity in the cooling system is reduced by dilution,
to, for example, 10% below the limit, before the biocide is added. The dilution
valve is then temporarily blocked.
Dilution inhibit After adding the biocide, the dilution should be inhibited for a while, until the
biocide that is present in the cooling system is mostly decomposed (observe
the statutory regulations!).
Implementation - The dilution function is only available in the “Conductivity measurement”
mode – not for concentration measurement.
- When the dilution function is activated, all the parameters that are irrelevant
for this function are switched off.
- The dilution function can be started through binary input 1 and stopped
through binary input 2, see "BINARY INPUT 1 and BINARY INPUT 2", Page
43.
The dilution function can also be stopped by using the
key.
- The present status of the dilution function will be shown in the display.
- The dilution valve is controlled by output K1.
- The addition of biocide valve is controlled by output K2.
- After dilution, K1 goes to the configured hold state (dilution inhibit).
EXIT