Desalination of Cooling Towers

Using untreated or partially softened water as the feed water for cooling water circuits or air washers usually causes problems such as:

– Limescale,
– Biological deposits by myxobacteria and algae (bacterial contamination)
– Corrosion of metallic materials.

Automatic monitoring and conditioning of the circulating water is important to prevent this from happening.

We have developed the automatic desalination device with controller MultiControl CT according to VDI 2047 part 1 and 2 for this application.

  • Desalination can be controlled either by conductance or by TDS. There is a locking mechanism to stop desalination after a biocide dosing. The duration of desalination can be monitored.
  • The biocide dosing may either take place after a certain number of days or regularly on certain days of the week at a fixed time. Preliminary desalination is available as an option.
  • For quantity-based inhibitor dosing, there are various adjustment options available for the dosing point and dosing period.
  • Circulation may either take place after a certain number of days or regularly on certain days of the week at a fixed time.
  • In addition, limit values, for example for temperature (min and max) or pH value (min and max) can be monitored.

By using different plug-in cards on the two existing slots in the device, various sensors, a process controller with 0/4-20 mA input or a curve tracer can be connected.

The following plug-in cards are available in particular:

  • Plug-in card for connecting a probe with two current outputs for measuring the inductive conductivity and temperature and for connecting a combination electrode for measuring the pH value.
  • Plug-in card for connecting a probe with RS232 interface for measuring the inductive conductivity and temperature.
  • Plug-in card for connecting a conductive conductivity probe, a PT100 or PT1000 temperature sensor with 2-, 3- or 4-wire technology and a combination electrode for measuring the pH value.
  • Plug-in card with two 0/4-20 mA outputs for outputting the measured values and one RS232 interface for connecting an inductive conductivity probe.

A SD card is used to log measured values, messages, alarms and status changes. Even the firmware can be updated in this way.

There is also the option of a wireless measured value enquiry. To do this, simply replace the SD card used in the device with our WLAN SD card. The files can then be loaded via a browser and displayed graphically.