Controlling waste introduction into pyrolysis chamber of disposal plant

摘要

A motorized screw conveyor (2) introduces waste; a fuzzy logic control system (19) sets screw speed (Nz) to a desired value (Ns). A temperature variable (Ts, dTs/dt, DELTA Ts) of the pyrolysis gas (G) forms an input value to the fuzzy system (19), which outputs the control signal (S) controlling screw (2) speed (Nz). An Independent claim is included for the corresponding pyrolytic waste disposal plant. Preferred features: The desired screw speed (Ns) corresponds to an adjustable waste mass feed rate (M). The fuzzy system (19) calculates variation in the desired value (NS), which is used to determine the required screw speed (NZ). A departure ( DELTA Ts) of pyrolysis gas temperature from set working point, is input to the fuzzy system. One or more of the following also serve: temperature (Th) of hot gas (H) heating the pyrolysis chamber (4). Temperature (Tf) of make-up steam (F) produced by a steam generator (16), blower (8) speed (Nh) for hot gas (H) heating the pyrolysis chamber, ratio of screw rotary speed to that of the pyrolysis chamber, degree of pyrolysis (P) of pyrolyzed residues (R) withdrawn. The fuzzy system is subdivided, e.g. into two subsystems. Each subsystem takes inputs. Output signals are compared, and especially weighted, the control signal (S) being derived from the result. Measured inputs to the subsystems are essentially those already described. Weighting of the subsystem outputs differs. Fuzzy logic controls heat input to the pyrolysis chamber.