Inventors:
William R. Phillips - Denver CO
Ronald D. Tate - Denver CO
Radon Tolman - Evergreen CO
Assignee:
Dravo Corporation - Pittsburgh PA
International Classification:
C22B 1506
Abstract:
A method of controlling a process off-gas system by generating a model of the input to the system as a function of the gas generating inputs to the process vessel served by the off-gas system and feeding forward this flow representation as the set point for a feedback flow control loop for the downstream off-gas system fans. The feed forward signal is trimmed by a process off-gas pressure feedback loop which when applied to a TBRC off-gas system assures a minimum flow of leakage air to prevent puffing. The flow control feedback loop employs a mass spectrometer to provide on line computation of the true off-gas flow at the fans. Since the input model can be generated as a simple linear function of the SCFM of the gas generating inputs to the process, the flow control loop is operated on the same basis although it can also be operated on the basis of mass flow.