Shut=off valve for gas duct - has lock chamber with rows of swivel louvre grooves

摘要

The shutoff valve for closing a large cross-sectional area gas duct comprises a lock chamber defined by the gas duct walls and the two rows of swivel louvre grills. These are held to the housing of the shutoff which accommodates a mechanical actuator. The louvre grills are arranged in the gas duct at an angle to the vertical plane to be spaced more widely apart in the top of the gas duct than in the bottom portion. When the gas duct is closed the lock chamber is filled with bulk free-flowing material from the top hopper located in the gas duct upper portion. When the gas duct is opened, the lock chamber is emptied of the bulk material. This is free to pour by gravity into the bottom receiving hopper, both of the hoppers being interconnected through a conveyor for the bulk material to return to the top hopper.