Patent ID: 6558515
Filing Date: 2003-05-06
Classification: B01D,Y10S

Abstract:
An apparatus for controlling the relative rate of upward vapor flow in each of two parallel, partial-column contacting sections located in a middle portion of a divided wall column, the column being divided into at least said two contacting sections by a vertical dividing wall, said apparatus comprising:a.) a first differential pressure measuring device measuring the pressure differential between vapor-filled volumes located immediately above and below a first dedicated perforated tray located in an upper portion of a first partial-column contacting section of said column; b.) a second differential pressure measuring device measuring the pressure differential between vapor-filled volumes located immediately above and below a second dedicated perforated tray located in an upper portion of a second partial-column contacting section of said column; c.) a liquid collection tray located in the column above the first and second partial-column contacting sections of the column, the liquid collection tray having a liquid collection well and also having openings allowing the upward flow of vapor through the liquid collection tray; d.) a liquid withdrawal and distribution conduit system communicating with the liquid collection well of the liquid collection tray and comprising conduits for the passage of liquid from the liquid collection well to other points in the fractionation column including a first conduit having an outlet discharging onto the first dedicated tray and a second conduit having an outlet discharging onto the second dedicated tray; e.) a first flow control valve located in the first conduit and controlling the rate of liquid flow through the first conduit in response to a signal generated by the first pressure differential measuring device; and f.) a second flow control valve located in the second conduit and controlling the rate of liquid flow through the second conduit in response to a signal generated by the second pressure differential measuring device.