Self scanning on line sensor system for automatic control of cooling and boiler water treatment

Operation of cooling tower and boiler systems requires frequent monitoring of water chemistry parameters to obtain the necessary information for adjustments to the water treatment program. Failure to perform the necessary adjustments can result in reduced service life and poor energy efficiency resulting from corrosion, scale and fouling. A hybrid absorbance/emission spectrometer is proposed as the key sensor in an on-line system for automatic monitoring and expert system control of cooling tower and boiler systems. The absorbance portion of the system uses a field proven technique for on-line analysis of process solutions using specially calibrated pattern recognition algorithms to interpret the UV-VIS absorbance signatures obtained at frequent intervals using a series of two flow cells of differing path lengths. The emission portion of the system is a patented technique that uses a special flow cell in series with the absorbance cells to energize a sample with an arc discharge and collect the resulting emission pulse using a fiber-optic probe. Absorbance and emission spectra are detected and interpreted using a common spectrograph and embedded computer. They system also includes non-optical sensors such as pH, conductivity, dissolved oxygen and temperature. The system is capable of simultaneously detecting the major water quality and treatment chemical parameters required to monitor and adjust cooling or boiler water treatment programs.