Falling strand devolatilizer using one preheater with two flash chambers

Claim 1

Improved falling strand devolatilizer apparatus comprising: A. a shell and tube heat exchanger means adapted for input, passage through, and discharge from, the tubes thereof of a process fluid and further adapted for receipt, passage through, and discharge from, the shell interior thereof of a heat exchange fluid whereby for heat transfer from said heat exchange fluid to said process fluid occurs during operation thereof, B. a first and a second vessel, each vessel having: 1. a generally tapered lower region terminating in a discharge port, 2. a vapor take-off port in an upper portion thereof, 3. an input port means adapted to discharge process fluid therein at a point bEtween said discharge port and said vapor take-off port, 4. jacket means with heat exchange fluid entrance and exit ports and adapted to heat said vessel, and first vessel being adapted to be positioned spatially above said second vessel, C. interconnection means joining the discharge port of said first vessel with the input port means of said second vessel, D. said heat exchanger means being interconnected with said first vessel and adapted to have the discharge end portions of said tubes thereof pass into and be in communication with the interior of said first vessel, E. first gas pump means interconnected with said vapor take-off port of said first vessel and adapted to maintain desired pressures in said first vessel, F. second gas pump means interconnected with said vapor take-off port of said second vessel and adapted to maintain desired pressures in said second vessel but below the desired pressures maintained in said first vessel, G. liquid pump means interconnected with the discharge port of said second vessel and adapted to remove process fluid therefrom without loss of desired pressure in said second vessel, H. variable fluid transfer plug valve means axially connected to said interconnection means and adapted to vary the rate of process fluid flow from the discharge port of said first vessel through said interconnection means and into the input port means of said second vessel, I. actuator means engaged with said fluid transfer valve means and adapted in response to control signals applied thereto to operate said fluid transfer valve means, J. level sensing means associated with said first vessel and adapted to measure fluid level in said lower region thereof and to generate a signal representative of fluid level when said first vessel is generally oriented so as to have its tapered lower region directed downwardly, K. controller means functionally interconnecting said level sensing means with said actuator means and responsive to a predetermined set signal and to signals from said level sensing means, said controller means being adapted to apply control signals to said actuator means after comparing said level sensing means signal to said set signal whereby a predetermined rate of process fluid flow from the discharge port of said first vessel through the input port means of said second vessel is maintainable when said devolatilizer apparatus is operating with first and said second vessels generally vertically oriented.