Patent ID: 7431058
Filing Date: 2008-10-07
Classification: B01J

Abstract:
1. In combination with a vessel at nonatmospheric pressure and with an elongated tubular lance for feeding a fluid into or out of the vessel and having an end provided with a nozzle, a nozzle-changing system comprising: a support tube fixed to and opening into the vessel at a nozzle seat, the lance being fittable in the tube in an inner position with the nozzle fitted to the seat; a main valve provided on the tube outward of the seat and displaceable between a closed position completely blocking flow through the tube and an open position permitting such flow, the lance in its inner position extending through the valve in the open position thereof; a plurality of seal rings spaced along the tube outward of the valve and fittable with the lance when same is in the tube to form respective annular compartments in the tube around the lance; and means including purge valves opening into the compartments for admitting fluids into and draining fluids from the compartments.