Water treatment controller for an evaporative condenser

An apparatus, for controlling the flow of a fluid through a system that has a drain valve and an inlet through which fluid is added to the system, said apparatus comprising:

• a sensor for detecting the conductivity of the fluid;
• means, coupled to said sensor, for opening the drain valve when the conductivity is greater than a first defined threshold level, and closing the drain valve when the conductivity is less than a second defined threshold level;
• means for indicating how long a period of time the drain valve is open;
• and
• means for signalling a possible malfunction of the system when said means for indicating indicates that the period of time the drain valve is opened exceeds a defined interval.

An apparatus for chemically treating fluid flowing through a device that has a drain valve and an inlet through which fluid flows into the device, said apparatus comprising:

• means for sensing the conductivity of fluid in the device;
• valve control means, coupled to said means for sensing, for opening the drain valve when the conductivity is greater than a first threshold level, and closing the drain valve when the conductivity is less than a second threshold level;
• means for measuring the volume of fluid that flows through the inlet;
• means for controlling the addition of a first chemical to the fluid flowing through the device in response to an indication received from said means for measuring that a first predefined volume of fluid has flowed through the inlet;
• means for controlling the addition of a second chemical to the fluid flowing through the device either in response to an indication received from said means for measuring that a second predefined volume of fluid has flowed through the inlet, or at a first specified time of day, as selected by the user;
• means for controlling the addition of a third chemical to the fluid flowing through the device either in response to an indication received from said means for measuring that a third predefined volume of fluid has flowed through the inlet, or at a second specified time of day, as selected by the user;
• and
• means for inhibiting the drain valve from being opened during one defined period following addition of the second chemical and during another defined period following addition of the third chemical, which opening of the drain valve might otherwise occur from erroneous sensing of conductivity due to chemical addition.