PURPOSE: To enable execution of reliable continuous measurement by measuring a pressure loss in the middle of a pipe leading a mixed flow of a powder body and gas from a reactive fluidized bed to a solid-gas separating device and by detecting a particle circulation amount from the value of the pressure loss and the value of gas flow velocity at that part.
CONSTITUTION: The direction of movement of particles and gas changes from the vertical direction to the horizontal in the upper part of a riser 11. Therefore the velocity of movement in the horizontal direction of the particles is accelerated from about zero gradually in the part of a horizontal pipe 20 and a force required for this acceleration depends on a particle circulation amount. The force required on the occasion comes out as a counterforce to the gas and a pressure loss of the gas. Therefore pressure takeout ports 16 and 17 are provided at two points separated at a prescribed distance from each other in the middle of the pipe leading a mixed flow of a powder body and the gas from a reactive fluidized bed 11 to a solid-gas separating device 13, and a differential pressure between the ports is measured continuously by a differential pressure oscillator 18. Under the conditions that the kind of the particles and positions of the pressure takeout ports are fixed, the particle circulation amount GS, the pressure loss P and the gas flow velocity U can be arranged by the equation ((a) and (b) are coefficients).
TAKAMOTO YASUSHI
EGASHIRA TATSUHIKO