Patent ID: 7415446

Claim:
An apparatus for automatically searching for the optimal operating point of a process, comprising: (a) a process having one variable input, a measured process variable which is a function of the output of said process, and a relationship between said input and said output that includes an optimal operating point at which said process transitions from a direct-acting to a reverse-acting mode or vice versa, said process selected from the group of processes consisting of; (i) a metal production process in which said variable input is the temperature of the metal oven or furnace and said measured process variable is a metallic property; (ii) a coal gasification process in which said variable input is the vapor to coal ratio and said measured process variable is the measurement of trace elements within coal; (iii) an ore mining process in which said variable input is the ore to water ratio and said measured process variable is the ore yield; (iv) a liquid pumping process in which said variable input is the speed of variable frequency drives (VFD) and said measured process variable is the ratio of total power consumption to liquid flow rate: (b) a minimum or maximum setter providing a source of setpoint signals; and (c) an optimizer connected to said setpoint signal source and said process variable, said optimizer being arranged to so vary said input as to cause said process variable to reach said optimal operating point and stay near thereto for optimizing the efficiency of said process, said optimizer including: (i) an acting mode search engine arranged to detect the direct-acting or reverse-acting mode of said process; and (ii) a maximum search engine arranged to detect if said process variable has reached a maximum value, and/or a minimum search engine arranged to detect if the said process variable has reached a minimum value.