Continuous ADT Monitor

Continuous Sulphuric Acid Dewpoint Temperature Monitor
It is necessary to know the temperature of sulphuric aicd dewpoint temperature(ADT) and exhaust gas for maintaining the operating efficiency of coal or oil-fired boilers. If the sulphuric acid dewpoint temperature is lower than the exhaust gas, then energy is wasted. Operating the boiler at temperatures below the sulphuric acid dewpoint temperature will result in the formation of sulphuric acid inside the boiler and particularly on the 'colder' parts of the plant.

1. The continuous Acid Dewpoint Monitor System adopts an air-cooled probe with a dewpoint detector at its measuring tip. The detector includes a thermocouple which measures detector temperature and a platinum electrode which measures the conductivity of any acid deposited on the detector surface. The probe is constructed from stainless steel and has an operating length of 1.2m/4ft. Within the Probe outer tube is a smaller tube which carries cooling air through a terminal block to the back side of the detector element.

The Electronic Control Unit (ECU) monitors the conductivity between the electrodes on the detector element and develops a control signal. This signal controls the MAFR and thus the temperature of the detector element, i.e., to obtain constant conductivity between the electrodes and ensures that the temperature of the detector element is maintained at the ADT.