Apparatus and process for pellet preheating and volatile recycling in a glass making furnace

Abstract

A glass making furnace having a preheater and recycling structure including a tubular housing having a lower gas receiving stack section, a top in the form of an inverted cone, a glass batch pellet containing intermediate section, having a lower portion over the cone and about the intermediate section, gas ports in the side of the cone, shield means over the ports, a discharge valve in the lower portion below the cone part, a hot gas stack extending over the upper portion of the pellet section, a fan or hot gas ejector at the top of the stack, a damper above the fan or hot gas ejector connecting with a pressure controller within the furnace for maintaining the pressure in the furnace slightly above atmospheric, an inlet valve outwardly of the upper portion of the pellet section to control the entrance of the pellets, a regenerator on each side of the melting section and port and burner means communicating with each regenerator, a reversing valve connected with the regenerators and the melting section, and a portion of the reversing valve connected with the cooler outside air and the regenerator being fired.

I claim: 
     
       1. A pellet preheater adapted to receive the exiting combustion gases from a glass furnace for heating pellets to be introduced to the glass furnace comprising a tubular hot gas stack section adapted to being connected to receive the exiting combustion gases from the glass furnace,   a top portion of the hot gas stack section being apertured to allow the combustion gases to pass therethrough,   a cylindrical exhaust tube to carry gases out of the preheater, and   a pellet containing stack section receiving and holding the pellets while they are heated and coated by the condensate from the combustion gases, said pellet stack section surrounding the hot gas stack section and the exhaust tube and including a lower portion, above that a reduced portion and above that a top section,   the lower portion of the pellet stack section surrounding the top portion of the hot gas stack section and including a discharge valve to allow discharge of the heated pellets from the preheater,   the top section of the pellet stack section surrounding the exhaust tube and including an intake valve to admit pellets to the preheater,   the reduced portion of the pellet stack section joining the top section and the lower portion of the pellet stack section and surrounding the exhaust tube, said reduced portion including an inwardly and downwardly sloping surface to heat the pellets by contact with the exhaust tube and the sloping surface of said reduced portion.   
     
     
       2. A pellet preheater as claimed in claim 1 wherein there is a fan connected to the exhaust tube to draw the exiting gas out from the pellet stack section of the preheater. 
     
     
       3. A pellet preheater as claimed in claim 1 wherein the intake valve and the discharge valve have the form of inverted cone-shaped surfaces to control the passage of pellets therethrough. 
     
     
       4. A pellet preheater as claimed in claim 1 wherein a downwardly and outwardly sloping surface connects the reduced portion and the lower portion of the pellet stack section to allow the lower section to have a greater volume capacity so as to allow for maximum contact between the combustion gas and the pellets. .Iadd. 5. The combination of a glass melting furnace having an exhaust duct, a pellet preheater having a hot gas stack section connected to said duct whereby any hot gasses may filter through any pellets in the preheater,   a pressure controller within said furnace,   valve means for regulating the exhaust discharge from said stack section,   and means operatively connecting said valve means with the pressure controller for maintaining the pressure in the furnace slightly above atmospheric, and concurrently coordinating selected pressures in the furnace and in the preheater,   and fluid circulating means upstream said valve means for causing increased movement of gas through the exhaust duct. .Iaddend..Iadd. 6. The invention according to claim 5 and said valve means comprising a damper. .Iaddend..Iadd. 7. The combination of a glass melting furnace having an exhaust duct,   a pellet preheater having a hot gas stack section connected to said duct,   a pressure controller within said furnace,   valve means for regulating the exhaust discharge from said stack section,   and means operatively connecting said valve means with the pressure controller for maintaining the pressure in the furnace slightly above atmospheric,   said stack having an outlet portion, and   an exhaust fan positioned in said outlet portion, and   said valve means comprising a damper positioned within said outlet portion downstream of the fan,   said damper including means for developing static pressure against the fan.   
     
     
        .Iaddend..Iadd. 8.  A glass making furnace having a preheater and recycling means including a tubular housing having a lower gas receiving stack section, a top in the form of an inverted cone, a glass batch pellet containing intermediate section, having a lower portion over the cone and about the intermediate section, gas ports in the side of the cone, shield means over the ports, a discharge valve in the lower portion below the cone part, a hot gas stack extending over the upper portion of the pellet section, a hot gas ejector at the top of the stack, a damper above said ejector, a pressure controller within the furnace operatively connected to the damper for maintaining the pressure in the furnace slightly above atmospheric, an inlet valve outwardly of the upper portion of the pellet section to control the entrance of the pellets, a regenerator on each side of the furnace, said furnace having a melting section between said regenerators, ports in the furnace and burner means communicating with the regenerators, a reversing valve connected with the regenerators and the melting section, and said reversing valve having a portion connected with the relatively cooler outside air and the regenerator being instantly fired. .Iaddend..Iadd. 9. The invention according to claim 5 and said pellet preheater being disposed in series between the furnace and said stack section and operative to extract heat from gasses passing therethrough whereby the gasses downstream thereof are cooler and upstream thereof, and said fluid circulating means including a fan and said valve means being cooperative with said fan and developing back pressure within the stack. .Iaddend..Iadd. 10. The invention according to claim 5 and a regenerator on each side of the furnace, said furnace having a melting section between said regenerators, ports in the furnace and burner means communicating with the regenerators, a reversing valve connected with the regenerators and the melting section, and said reversing valve having a portion connected with the relatively cooler outside air and the regenerator being instantly fired. .Iaddend. .Iadd. 11. An improved process of making glass in a furnace having a main furnace melting section and a preheater and recycling structure comprising a glass batch pellet containing section communicating with said main furnace section, the steps of;   a. circulating heated gasses from the main furnace section through the glass batch pellet containing section; and   b. maintaining the pressure in the furnace slightly above atmospheric pressure by throttling the exhaust of gasses from the furnace downstream of said glass batch containing section and thereby increasing recirculation of the gasses through said glass batch containing section.   
     
     
        .Iaddend..Iadd. 12.  The process according to claim 11 and controlling the throttling in response to variations in pressure in the main melting section of the furnace. .Iaddend..Iadd. 13. The process according to claim 12 and heating the main furnace melting section by regenerators on each side thereof and controlling the heating by a reversing valve connecting the regenerators and main furnace melting section with cooler outside air and the regenerator being fired. .Iaddend.