1. A method for reacting one or more compounds in a reactor feed gas and exchanging heat between the reactor feed gas and a reactor product gas, the reaction and heat exchange occurring in a reactor apparatus comprising a reaction vessel having a wall and a reaction chamber in which the reaction occurs, the apparatus further comprising a shell and tube heat exchanger for transferring heat between the reactor feed gas and reactor product gas, the shell and tube heat exchanger comprising a shell that is in fluid communication with the reaction chamber and a tube bundle within the shell with a chamber being formed between the tube bundle and the shell, the tube bundle extending through the wall into the reaction vessel, the bundle comprising a plurality of central tubes and a plurality of peripheral tubes between the central tubes and the shell, the tubes being in fluid communication with the reaction chamber, the method comprising:
introducing the reactor feed gas into the peripheral tubes and central tubes of the shell and tube heat exchanger;
discharging the reactor feed gas into the reaction vessel to cause one or more compounds of the reactor feed gas to react and to form the reactor product gas;
introducing the reactor product gas into the chamber formed between the tube bundle and the shell; and
discharging the reactor product gas from the shell.
2. The method as set forth in claim 1 wherein the reactor feed gas comprises silicon tetrachloride and hydrogen, the silicon tetrachloride reacting with hydrogen to produce a reaction product gas comprising trichlorosilane and hydrogen chloride in the reaction vessel.
3. The method as set forth in claim 2 further comprising:
introducing the trichlorosilane discharged from the shell and tube heat exchanger into a second reaction vessel to produce polycrystalline silicon and silicon tetrachloride by-product; and
introducing the silicon tetrachloride by-product into the peripheral and central tubes of the shell and tube heat exchanger.
4. The method as set forth in claim 3 wherein the trichlorosilane is purified prior to introduction into the second reaction vessel.
5. The method as set forth in claim 2 wherein the reactor feed gas is heated to at least about 600\xb0 C. before being discharged from the shell and tube heat exchanger.
6. The method as set forth in claim 2 wherein the reactor product gas is cooled to less than about 550\xb0 C. before discharged from the shell and tube heat exchanger.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An air heater for heating air entering a combustion chamber of an internal combustion engine, the air heater comprising:
a heating element having a substantially planar portion and a flange portion, said flange portion being positioned at an angle to said planar portion, said planar portion being positioned within an air flow at an upstream location relative to said flange portion; and
a structure to position said heating element in communication with the air entering the combustion chamber of the engine.
2. The air heater of claim 1 wherein said flange portion is substantially planar.
3. The air heater of claim 2 wherein said heating element includes a plurality of 180 degree bends and a plurality of planar portions positioned between said bends, said heating element further including a plurality of flange portions positioned adjacent said plurality of planar portions, wherein said planar portions are spaced apart from and positioned substantially parallel to one another.
4. The air heater of claim 3 wherein said flange portions are spaced apart from and positioned substantially parallel to one another.
5. The air heater of claim 1 wherein said heating element is a one-piece contiguous component having said flange portion integrally formed with said planar portion.
6. The air heater of claim 5 wherein said flange portion extends less than a full length of said planar portion and includes a body interconnected at its ends to said planar portion by end portions extending at an angle from said planar portions.
7. The air heater of claim 5 further including another heating element spaced apart from said heating element, said another heating element having a flange portion and a planar portions, said planar portions of said heating element and said another heating element being positioned substantially parallel to one another.
8. An air heater for heating air entering a combustion chamber of an internal combustion engine, the air heater comprising:
a one-piece heating element positioned within an air flow, said heating element having a substantially planar portion and an upset portion, said upset portion extending at an angle to said planar portion along a trailing edge of said heating element; and
a structure coupled to position said heating element, said structure being operable to maintain the position of said heating element in communication with the air entering the combustion chamber of the engine.
9. The air heater of claim 8 wherein said structure includes a plate adapted to be positioned between an engine head and an intake tube of the engine.
10. The air heater of claim 9 wherein said plate includes an integrally formed stanchion and a fastener attaching said heating element to said stanchion.
11. The air heater of claim 10 wherein said fastener and stanchion are configured to allow relative movement therebetween when said heating element increases in length as a temperature of said heating element increases.
12. The air heater of claim 8 wherein said heating element includes a plurality of 180 degree bends and a plurality of planar portions positioned between said bends, said heating element further including a plurality of flange portions positioned adjacent said plurality of planar portions, wherein said planar portions are spaced apart from and positioned substantially parallel to one another.
13. An air heater for heating air entering a combustion chamber of an internal combustion engine, the air heater comprising:
a frame having an aperture extending therethrough;
a heating element having first and second ends, said heating element being positioned in communication within said aperture; and
a retainer coupling said first end of said heating element to said frame, said retainer being operable to move relative to said frame to allow said heating element to thermally expand and contract during operation of said heater.
14. The air heater of claim 13 wherein said retainer includes a fastener captured within a slot formed in said frame, said fastener being restricted from movement in a first direction and allowed to move in a second direction substantially perpendicular to said first direction.
15. The air heater of claim 14 wherein said slot is open at one end.
16. The air heater of claim 14 wherein said frame includes a stanchion having first and second opposite faces, said fastener having a first and second spaced apart flanges, said first flange being positioned on the same side of said stanchion as said first face, said second flange being positioned on the same side of said stanchion as said second face, wherein said first and second flanges are operable to limit the movement of said fastener relative to said stanchion in said first direction.
17. The air heater of claim 16 wherein said heating element is clamped between said first flange and a nut threadingly engaging said fastener.
18. The air heater of claim 17 further including another heating element positioned in communication with said aperture, said another heating element being clamped between said second flange and another nut threadingly engaging said fastener.
19. The air heater of claim 18 wherein said fastener includes a first part separable from a second part, said first part including said first flange, said second part including said second flange.
20. The air heater of claim 19 wherein said first part is threadably coupled to said second part.