Patent ID: 7812102

Claim:
A method of producing a polymer in a continuously operated gas phase reactor having two outlets from the reactor for collecting polymer product, the method comprising: polymerizing at least one monomer in a bed containing active catalyst formed by catalyst and polymer particles suspended in a fluid, said bed defining a fluidized bed level in said reactor; continuously withdrawing polymer powder from the reactor through a first of the two outlets: adjusting a discharge rate of the polymer powder so as to maintain a substantially constant bed level during polymerization; and separately recovering particle agglomerates from the reactor by discontinuously withdrawing the particle agglomerates from a second of the two outlets, the second outlet being different from the first outlet, wherein the discharge rate of the polymer powder is adjusted by using a continuously operated control valve, and the operation of the control valve is adjusted by using a control signal obtained from a bed level controller, and wherein the control valve is adjusted to provide for pulsating operation to prevent clogging of the valve.