摘要 |
A valve for feeding abrasive particulate material to, and removal of particulate material from a pressurized vessel, adapted to operate at temperatures above 500 DEG C., comprises a valve structure wherein a single shutoff member of generally spherical shape performs both functions of shutoff the particulate material and the gas-tight sealing by means of a resilient inflatable circular seal element which engages the convex side of said shutoff member. Said seal element is inflated and cooled by a pressure regulated and continuously flowing stream of liquid water. The seal element is protected from being damaged at high temperatures by contacting it with the cooled shutoff member when the valve is closed and with a cooled circular extension of the shutoff member when the valve is open. |