Upblast Exhaust Apparatus With A Variable Outlet Nozzle

Abstract

A radial upblast exhaust apparatus includes a fan housing having a fan inlet to receive air to be exhausted and a fan outlet to expel air to be exhausted. An upper housing is positioned immediately above the fan housing. It includes a first wall section and a second wall section each shaped as a partial conical section being concaved toward each other. The upper housing forms an air outlet nozzle. A mechanism changes the outlet area of the outlet nozzle in order to provide a variable area outlet for the fan.

What is claimed: 
     
         1 . An exhaust apparatus comprising:
 a fan housing having a fan inlet to receive air to be exhausted and a fan outlet to expel air to be exhausted; and   an upper housing positioned above said fan housing, said upper housing defining a central opening, and an annular air outlet nozzle that is disposed adjacent the central opening and is in fluid flow communication with said fan housing through said fan outlet to receive exhaust gas therefrom, the upper housing including a first wall section and a second wall section, each wall section being shaped as a partial conical section being concave toward the other wall section, said wall sections forming a radial upblast exhaust apparatus;   wherein the outlet nozzle defines an outlet area that is adjustable so as to provide a variable discharge of gas, and the first and second wall sections of the upper housing each includes an inner wall and an outer wall that is outwardly displaced from the inner wall, wherein the inner and outer walls define the air outlet nozzle therebetween, and the inner wall is movable so as to change the outlet area of said outlet nozzle.   
     
     
         2 . (canceled) 
     
     
         3 . (canceled) 
     
     
         4 . The exhaust apparatus of  claim 1  wherein said inner walls each have a flexible panel which is moveable so as to move the inner walls with respect to the outer walls and change the outlet area of said outlet nozzle. 
     
     
         5 . The exhaust apparatus recited in  claim 4 , wherein the inner walls have panels which are movable about an axis so as to change the outlet area of said outlet nozzle. 
     
     
         6 . The exhaust apparatus recited in  claim 5  wherein said flexible panels are interconnected to move in unison about an axis of each flexible panel. 
     
     
         7 . The exhaust apparatus recited in  claim 6  further comprising a mechanism for changing the outlet area of said outlet nozzle to provide a variable discharge of gas, wherein the mechanism comprises:
 a drive mechanism connected to one of said flexible panels; 
 and a means for driving said drive mechanism to adjust said flexible panels to change the outlet area of said outlet nozzle. 
 
     
     
         8 . The exhaust apparatus recited in  claim 7  wherein said drive mechanism comprises:
 a drive screw connected to one of said flexible panels; 
 and a motor for driving said drive screw to adjust said flexible panels to change the outlet area of said outlet nozzle. 
 
     
     
         9 . The exhaust apparatus recited in  claim 8 , wherein said drive screw is manually operated to change the outlet area of said nozzle. 
     
     
         10 .- 28 . (canceled) 
     
     
         29 . An exhaust apparatus comprising:
 a fan housing having a fan inlet to receive air to be exhausted and a fan outlet to expel air to be exhausted; and   an upper housing positioned above said fan housing, said upper housing defining a central opening, and an annular air outlet nozzle that is disposed adjacent the central opening and is in fluid flow communication with said fan housing through said fan outlet to receive exhaust gas therefrom;   wherein the outlet nozzle defines an outlet area that is adjustable so as to provide a variable discharge of gas, the upper housing includes a first wall section and a second wall section, the first and second wall sections each include an inner wall and an outer wall that is outwardly displaced from the inner wall, the inner and outer walls define the air outlet nozzle therebetween, and the inner wall is movable with respect to the other wall so as to change the outlet area of said outlet nozzle.