Patent ID: 7309610

Claim:
A method for dynamically controlling the expansion of a fluid bed reactor system, comprising: (i) providing a reactor vessel that has an inlet and an outlet and that contains: (a) a headspace that comprises carrying medium and that is substantially void of fluidized particles, wherein said carrying medium is a liquid, (b) a bed of fluidized particles in the carrying medium, and (c) a floating body that floats on top of the carrying medium in said headspace; (ii) providing at least one particle density detector comprising an electromagnetic transmitter, a receiver and a sensor head, wherein: (a) said density detector is mounted to said floating body such that the sensor head is positioned in said bed of fluidized particles, (b) said density detector detects the density of the fluidized particles in said bed of fluidized particles at a position that is level with said sensor head, and (c) said density detector generates a signal upon comparing the density detected with a pre-determined density; (iii) providing a flow controller that controls the flow velocity of the carrying medium according to the signal from said density detector; (iv) measuring and comparing continuously the density of the fluidized particles with the pre-determined density by said first density detector; and (v) continuously adjusting the flow velocity of said carrying medium by said flow controller as a function of said measuring and comparing.