Valve system

A valve for handling a hot fluid material, particularly, a fine particulate material such as the coal dust formed in the smelting of direct reduced iron ore, comprising:

• an upper valve portion defining an upper passageway for receiving the hot fluid material;
• a lower valve portion defining a lower passageway for expelling the hot fluid material;
• a valve closure member which is slidably positionable in a closed position to block a flow of the hot fluid material from said upper passageway to said lower passageway, and in an open position wherein the flow of the hot fluid material from said upper passageway to said lower passageway is allowed;
• said valve portions including a sleeve region which is proximate to said passageways and an outer valve region which is distal from said passageways, said sleeve region and outer valve region substantially surrounding said passageways and defining at least one annular cavity therebetween which also substantially surrounds said passageways;
• said at least one annular cavity being adapted to receive a non-fluid insulating medium such as a ceramic material which heat-insulates said valve while maintaining a temperature difference between said sleeve region and said outer valve region;
• a valve passage positioned to carry an elongated shaft having two opposite ends, one end of said shaft being attached to said valve closure member, and the other end of said shaft being adapted for securement to a means for causing said slidable positioning of said valve closure member;
• said elongated shaft including a passage formed therein for carrying a fluid for cooling said elongated shaft in such a manner that the cooling fluid is confined to said elongated shaft.