Walchem WIND Controller for Chlorination of Drinking Water

The Problem:

There are many places throughout the country where clean drinking water is required, but due to low population or a remote setting a SCADA system cannot be feasibly employed. Rural water systems with their limited funds must meet the same requirements as large municipalities. The WIND utilizing its chlorine and pH sensors can control this application and provide remote communications for reporting and compliance with minimal expense.

The system can be set up for proportional or PID control in conjunction with our chemical pumps to provide accurate chemical control. Pulse proportional control can be selected and used to increase or decrease the pump output based on the deviation from the set point. Pulse proportional control will reduce costs by about $300 per control point (ex. – chlorine or pH) when compared to a 4-20 mA signal.

Market drivers

  • The stimulus package added $615 million for rural water system upgrades
  • There are 147,000 small drinking water systems in the US
  • These systems lack the funding for high-end SCADA systems and many other control packages
  • Over 90% of the public water systems determined to be in significant non-compliance are small systems serving 3,300 or fewer users
  • The EPA approved amperometric sensors (membrane) for primary reporting of chlorine residuals as of November 2009

The Solution

The complete system should be composed of a:

  • WIND Controller
  • Chlorine and pH sensors
  • 4-20 mA input board – for input of turbidity, dissolved O2, chemical level
  • Flowmeters- to measure water throughput
  • Chemical pumps- for chlorine and pH adjustment
  • Posiflows-for verification of chemical feed
  • Ultrasonic Level Monitor for chemical tanks
  • Cell modem or land line for communications

The system will provide real time information on chlorine residuals, pH, flow, chemical tank levels or any other device outputting a 4-20mA signal. You also receive alarms for low residuals, low tank level and loss of chemical pump prime. System summaries will be sent daily and data logging can occur as often as every 15 seconds with supporting graphs.  Other equipment can be added such as arsenic removal filters, turbidity monitors, etc. and controlled by the same WIND.

blog12img01Typical WIND controlled water treatment system


For more information please call our knowledgable RHFS sales staff at 800-848-1141..