Claims
- 1. An apparatus for producing a high pressure thermal vapor stream of steam and combustion products substantially free of oxidizing gases by burning a fuel in about stoichiometric amounts of air comprising:
- casing means having plural, substantially cylindrical, refractory lined combustion zones of varying diameters forming a multiple zone combustion chamber extending along the longitudinal axis of the casing means;
- said casing means having means sealing one end thereof and connecting means on an opposite end thereof for connection with a vapor producing vessel means;
- a first zone of said plural refractory lined combustion zones having first a predetermined inner diameter for flowing gases therethrough;
- first injection means for introducing predetermined volumes of air and fuel into said first zone and igniting the air and fuel therein;
- second air injection means for injecting a second predetermined volume of air into said first zone adjacent said first injection means to cause turbulence and intermixing of the air and fuel in said first zone to facilitate complete combustion;
- a second zone of the plural refractory lined combustion zones for receiving the flow of gases from said first zone and having a greater inner diameter than said first zone to provide maximum turbulence as the combustion products rapidly expand therein to provide substantially complete combustion of the mixture forming a hot gas stream substantially free of oxidizing gases;
- a third zone of the plural, substantially cylindrical, refractory lined combustion zones for receiving the flow of gases from said first and second zones and having a greater inner diameter than said second zone for rapidly expanding the combustion gases to maintain maximum turbulence as the combustion products expand to facilitate complete combustion; and
- vapor producing vessel means for receiving the combustion gases to form a product stream of steam and combustion products through direct contact between the combustion gases and water.
- 2. The apparatus as set forth in claim 1, wherein:
- said secondary air injection means includes a plurality of passageways extending through said first zone refractory lining at an acute angle to the direction of flow of gases through said zones and inwardly oriented in the direction of said second zone to cause turbulence and intermixing in said first zone.
- 3. The apparatus as set forth in claim 1, further including:
- a final zone of the refractory lined combustion zones for receiving the flow of gases from said first, second and third zones and having a smaller inner diameter than said third zone for increasing the velocity of the combustion products to maintain turbulence and facilitate complete combustion.
- 4. The apparatus as set forth in claim 3, wherein:
- said final zone has a smaller inner diameter than said first zone to increase the velocity and maintain turbulence to facilitate complete combustion.
- 5. The apparatus as set forth in claim 1, wherein:
- the ratio of the inner diameter of said first zone to that of said second zone is in the range of from about 63% to about 78% to provide controlled expansion of the combustion gases to cause maximum turbulence of the gases flowing through the combustion zones.
- 6. The apparatus as set forth in claim 1, wherein:
- the ratio of the inner diameter of said second zone to that of said third zone is in the range of from about 78% to about 93% to provide controlled expansion of the combustion gases to cause maximum turbulence of the gases passing through the combustion chamber.
- 7. The apparatus as set forth in claim 3, wherein:
- the ratio of the inner diameter of said fourth zone to that of said third zone is in the range of from about 32.5% to about 47.5% to increase the velocity and turbulence of the combustion gases for substantially complete combustion.
- 8. The apparatus as set forth in claim 2, wherein:
- said plurality of passageways are equally spaced circumferentially about said first zone.
- 9. The apparatus as set forth in claim 1, including:
- said casing means having an outer cooling chamber means surrounding said casing means for receiving cooling water for protecting said casing means and said refractory lining thereof from overheating and for preheating the water for said vapor producing vessel means.
- 10. The apparatus as set forth in claim 1, including:
- said first zone having a transition zone with a gradually increasing diameter from that of said first zone inner diameter to said second zone inner diameter to control expansion and avoid hot spots in said refractory lining.
- 11. The apparatus as set forth in claim 1, including:
- said second zone having a transition zone with a gradually increasing diameter from that of said second zone inner diameter to said third zone inner diameter to control expansion and avoid hot spots in said refractory lining.
- 12. The apparatus as set forth in claim 1, including:
- said first injection means having a cylindrical air passageway communicating with said first zone.
- 13. The apparatus as set forth in claim 12, including:
- said first injection means having fuel injection means at a center portion of said first zone and surrounded by said cylindrical air passageway.
- 14. The apparatus as set forth in claim 1, including:
- a final zone of said refractory lined combustion zones for receiving the flow of gases from said first and second zones and having a smaller inner diameter than said first zone for increasing the velocity of the combustion products to maintain turbulence and facilitate complete combustion.
- 15. A method of producing a high pressure thermal vapor stream of water vapor and combustion gases substantially free of oxidizing gases from burning a substantially stoichiometric ratio of fuel and air, comprising:
- injecting a predetermined fuel and primary air ratio at a first location into a first refractory lined zone of a combustion chamber having a first diameter and igniting the fuel therein;
- injecting a predetermined volume of secondary air mixture at a second location into the first zone to cause turbulence and mixing of the air and fuel in the first zone;
- rapidly expanding the ignited gas mixture flowing from the first zone into a second refractory lined combustion zone having a larger diameter than the first zone to provide maximum turbulence as the mixture expands to facilitate substantially complete combustion of the mixture forming a hot gas stream substantially free of oxidizing gases;
- further expanding the gas mixture into a third refractory lined combustion zone for receiving the flow of gases from said first and second zones and having a larger diameter than said second zone for rapidly expanding the combustion gases to maintain maximum turbulence as the combustion products expand to facilitate complete combustion; and
- flowing the hot gas stream from the third zone through a final refractory lined combustion zone into a vapor producing vessel to form a product stream of water vapor and combustion gases through direct contact between the combustion gases and water.
- 16. The method as set forth in claim 15, including the step of:
- rapidly expanding the predetermined air-fuel mixture flowing from the second zone into a third refractory lined combustion zone having a larger diameter than the second zone before flowing to the final zone to provide maximum turbulence to facilitate complete combustion.
- 17. The method as set forth in claim 15, wherein:
- the step of injecting the secondary air includes directing the secondary air substantially adjacent the point of initial combustion in the first zone to mix with unburned fuel to facilitate complete combustion.
- 18. The method as set forth in claim 16, including the step of:
- flowing the gases from the third zone into the combustion zone having a reduced diameter to increase the velocity of the combustion gases after the second expansion thereof to maintain turbulence for facilitating complete combustion and for exhaust from the combustion chamber.
- 19. The method as set forth in claim 15, wherein:
- the step of expanding includes expanding the gas mixture in a transition zone portion of the first zone having a gradually increasing diameter to the second zone to avoid causing hot spots in the combustion chamber during expansion.
- 20. The method as set forth in claim 15, including the step of:
- supplying cooling water under pressure about the periphery of the combustion chamber to cool the chamber and to preheat the water for the vapor producing vessel.
- 21. The method as set forth in claim 17, wherein:
- said step of injecting the secondary air includes injecting the secondary air circumferentially about the first location to cause turbulence and to thoroughly mix the fuel and air for facilitating substantially complete combustion.
- 22. The method as set forth in claim 18, wherein:
- said step of flowing the gases into the final zone includes increasing the velocity of the gases by flowing gases in the final zone having a diameter less than the first zone.
Government Interests
The government of the United States of American has rights in this invention pursuant to Contract No. EY-76-C-02-2880 awarded by the U.S. Energy Research and Development Administration.
US Referenced Citations (6)
Foreign Referenced Citations (1)
Number |
Date |
Country |
105,472 |
Feb 1971 |
MXX |