Patent ID: 6460412
Filing Date: 2002-10-08
Classification: B01J,C08F,G01F,G01N

Abstract:
Method of measuring a dynamic fluidized-bed level in a fluidized-bed olefin polymerization reactor, said reactor having a top wall and said fluidized bed having a superficial gas velocity of 0.3 to 3.5 feet per second and including bubbles bursting at said fluidized-bed level, said bubbles having an average diameter of 0.05 meter to 4 meters, comprising transmitting a series of short pulses of ultrasonic waves or microwaves from said top wall toward said fluidized-bed, receiving from said fluidized-bed level reflections of at least 0.01% of said ultrasonic or microwave pulses, calculating the times between said transmission and reception of said pulses, and calculating said bed level from said times.