FEEDBACK LOOP CONTROL FOR SOIL EVAPORATIVE DESORPTION

摘要

Active or closed feedback/feedforward loop controls may be used to improve operation of a thermal desorption process. Characteristics of the thermal desorption process may be monitored, e.g., carbon monoxide concentration, and then may be used to predict the end point of the thermal desorption process. Inputs and effluent treatment elements may also be modulated to further optimize the treatment time and quality (completeness) and to avoid any unwanted effects associated with excess processing. Post-treatment gas comprising non-condensed condensable hydrocarbon contaminants may be recycled as pre-treatment gas or used to heat fresh air. Mean free paths of the exhaust gas exiting a thermal desorption chamber are restricted to limit the flame propagation and explosion fronts. Temperature and concentration of flammable elements may be monitored and controlled to prevent explosion hazards. An isolation valve and a pressure relief chimney may also be coupled to the exhaust of the thermal desorption chamber.