PURPOSE: To stabilize the level of an ore supply hopper at a level near the upper limit by adding an in-and-out balance quantity of raw material to an intermittent discharge quantity of an ore supply hopper when the in-and-out balance quantity of raw material in the hopper exceeds a specified value, and supplying only the intermittent discharge quantity of raw material when the in-and-out balance quantity is below the specified value to control the intermittent discharge quantity of raw material from a mixing tank to a transport conveyer.
CONSTITUTION: The in-and-out balance quantity of raw material in an ore supply hopper 4 is calculated as a required storage quantity depending upon a difference between the intermittent discharge quantity from the ore supply hopper 4 and the quantity of raw material supplied to the ore supply hopper and upon a difference between the preset value and a measured value of an ore supply hopper level. When the in-and-out balance quantity exceeds a specified valve, an in-and-out balance quantity of raw material is added to the intermittent discharge quantity of the ore supply hopper 4 to control the quantity of raw material supplied from mixing tanks 11W1n to a transport conveyer. When the in-and-out balance quantity is below the specified value, the quantity of raw material supplied from the mixing tanks 11W1n to the transport conveyer is controlled according to only the intermittent discharge quantity of the ore supply hopper 4, so that the ore supply hopper level is stabilized approximately at the upper limit.
YASUMOTO TOSHIHARU
NIKO KIYOSUKE
