| 摘要 |
PURPOSE:To control the quantity of a mineral fed simply and accurately by a method wherein the pressure of the bottom of a fluid layer and an upper portion of the fluid layer is measured blowing a small quantity of gas into the fluid layer from a pressure source, and the speed of a raw material feeder is controlled by the differential pressure. CONSTITUTION:The pressure of the bottom of a fluid layer is measured by means of a pressure gauge 14 in a pressure measuring tube 17 while blowing a small amount of gas adjusted by means of a reducing valve 13 into the fluid layer 5 through the pressure measuring tube 17. Meanwhile, pressure is measured by means of a pressure gauge 12 at an upper portion of the fluid layer 5. Both measuring value is inputted to a differential pressure transmitter 23 and converted into differential pressure, and the differential pressure is inputted to a deviation indicating regulator 24. The deviation indicating regulator 24 adjusts the speed of revolution of a rotary valve 19, a feeder of a raw material hopper 21, through a variable speed motor 20 according to the differential pressure transmitted and set value. Raw material passes through a chute 3 according to the speed of revolution of the valve 19 and is fed to the fluid layer 5. According to this method, the thickness of the fluid layer 5 can be kept constant. |
