Seawater analyser requires no chemicals

The new Model DCA-23 from Electro-Chemical Devices can monitor seawater chlorine levels accurately in a range of industrial process and municipal water treatment applications.

Seawater desalination plants chlorinate and dechlorinate water before processing. While the chlorination of seawater inhibits the growth of marine life on the various filters, screens and heat exchanger surfaces, the seawater must be dechlorinated for environmental reasons before it is discharged back into the original water supply.

The DCA-23 is a single-purpose analyser that monitors chlorine in seawater from 0.0 to 2.00 ppm. It measures the pH, temperature and total residual oxidant (TRO) of seawater and converts them into an equivalent ppm chlorine value, which is displayed to conform with existing conventions. It features a minimum detection limit (MDL) of 0.014 ppm and a limit of quantification (LOQ) of 0.044 ppm, making it suitable for monitoring in environments following stringent dechlorination regulations. 

 The DCA-23 features three sensors, pH, TRO and temperature: the pH sensor measures from 0-14 pH, the TRO sensor measures from ±1500 mV and the temperature sensor measures from 0-100°C. 

Specific applications for the analyser include the re-gasification process at LNG terminals, seawater cooling at thermal and nuclear power plants and water desalination plants.

The DCA-23 seawater dechlorination analyser is available in five configurations:  Loop powered, 4-20 mA = 0.00 to 2.00 ppm Cl; 24VDC powered with two 4-20 mA outputs, Cl and pH; 24VCD powered with two 4-20 mA outputs and two alarm relays; 110 VAC powered with two 4-20 mA outputs and two alarm relays; and 220 VAC powered with two 4-20 mA outputs and two alarm relays. The maximum system pressure and temperature rating is 50 psig at 60°C.

The rack mounted system is plumbed with ¾ inch schedule 80 pipe, with slip fittings for input and drain. The T-23 Analyzer, 2 sensors, pH flow cell and TRO flow cell are rack mounted using 1? inch x1? inch Uni-Strut rail.