Electrochemical Chlorine Dioxide Generation Systems

Pureline PureClO₂ HP Series Electrochemical Chlorine Dioxide Systems

Application: Chlorine Dioxide disinfection of process water for contact with food products.
Raw water is pumped from the local river into a 1ML underground storage dam. This water is continually circulated with a small centrifugal pump. Chorine dioxide solution is generated with an HP-40e electrochemical generator and dosed into this recirculation line on the basis of the chlorine dioxide setpoint of 0.40 ppm. Chlorine dioxide residual is measured using a ProMinent D1C transmitter and CDE2-mA-2ppm amperometric probe. Using a Dioxide Pacific PID controller and the make-up water flow signal, a PID control output is calculated which is provided as a 4-20mA signal to a ProMinent S3Ca dosing pump.

The HP-40e chlorine dioxide generator is located inside a plant room with IBC storage of Purecide E chemical inside a fibreglass IBC bund. Chemical flows under gravity to the generator. 20% caustic is produced as a free by-product and this is collected in a 500L HDPE tank from which it is pumped to a bulk storage tank for re-use.

The complete system is controlled with a Schneider PLC and touchscreen which interface with the site SCADA system.

electrochemical chlorine dioxide generator


Old system before replacement with evident corrosion from chlorine dioxide and acid	New system showing painted plant room with new generator and chemical store

This application has used chlorine dioxide for 10 years using a concentrated chemical acid-chlorite generator. This system worked well but came to the end of its working life due to corrosion from chlorine dioxide solution and hydrochloric acid fumes.

Dioxide Pacific was responsible for removing the old acid-chlorite chlorine dioxide generator and replacing it with the new electrochemical generator and control system. This was done in a short time period to minimise disruption to production processes.

This turnkey system was installed and commissioned within 6 weeks and is maintained by Dioxide Pacific with a preventative maintenance contract.

Application: Chlorine Dioxide disinfection of poultry processing chiller water and process water.
Chilled water at around 4 deg.C is used inside a spin chiller for processing poultry carcasses. The carcasses enter the chilled water and spend time in this water as the temperature of the carcass decreases. In order to inactivate E.Coli, Salmonella and other micro-organisms, chlorine dioxide is dosed into the chiller water to maintain a concentration of 5 ppm. It is not possible to measure chlorine dioxide in this environment with an amperometric probe as the blood, fat and other organics would foul the membrane cap and cause overdosing. Redox (ORP) is the preferred method where 650 mV equates to 5 ppm.

Chlorine Dioxide is generated using the Pureline PureClO₂ HP-40e generator and dosed into chiller water using three ProMinent S1Ca dosing pumps. The dosing pumps each have proportional control loops from D1C redox transmitters, providing 4-20mA control signals to the dosing pumps.

The customer has reported an increase of shelf life of 7-10 days since chlorine dioxide use started. Prior to chlorine dioxide, sodium hypochlorite dosing was used and this was controlled manually to 30 ppm.

Chlorine dioxide is also dosed into process water at 0.40 ppm. This disinfected water is used generally throughout the site for washing.


Pureline HP-40e chlorine dioxide generator installed in chemical store	Chlorine dioxide generator

Chlorine dioxide dosing pumps	Chlorine dioxide dosing control system

Application: Chlorine Dioxide sanitisation of UF, NF and RO membranes
Chlorine Dioxide can be dosed continuously at 1 ppm to prevent biological fouling with UF, NF and RO Membranes. Alternatively, chlorine dioxide can be dosed intermittently during programmed cleaning cycles. The advantage of chlorine dioxide in this application is that oxidative damage to the membranes is prevented and excellent disinfection is obtained with the benefit of very low running cost. Chlorine dioxide is present in the concentrate and permeate streams.

Tests have been done with many of the major membrane brands to confirm compatibility with chlorine dioxide. Please contact us for further detailed information.

Other Applications:

Disinfection of chilled water for elimination of Listeria and E.Coli for vegetable processing water.
CIP sanitisation for beverage processing. Replacement of peracetic acid.
Potable water disinfection - THM reduction, Cryptosporidium inactivation.
Plant nursery recycled irrigation water - disinfestation of plant pathogens.
Disinfection of lettuce wash water - Listeria inactivation.
Disinfection of Legionella in recirculating warm water systems or cooling towers.
Disinfection of cooling tower water in the presence of ammonia.
Disinfection of once through sea water cooling circuits for macro and micro fouling control.

For more information on electrochemical chlorine dioxide dosing systems or to obtain a quotation, please complete the feedback form on our Contact page.