Gas fired process heater with ultra-low pollutant emissions

Patent metadata

Field	Value
Publication number	US-11519635-B2
Application number	US-201916547873-A
Country	US
Kind code	B2
Filing date	Aug 22, 2019
Priority date	Aug 24, 2018
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

Process heaters and associated methods of processing with ultra-low pollutant emissions are provided. The process heaters and methods utilize a heat exchange tube having disposed therein a radiant permeable matrix burner at a first end of the tube. The tube further includes a thermally insulated insert disposed adjacent the radiant burner opposite an oxidant-fuel mixer that feeds the burner. The process heaters and methods act to reduce emissions of CO and NOx.

First claim

What is claimed is:

1. A process heater comprising:
a tank adapted to contain a body of liquid;
a heat exchange tube including at least a first end disposed in the body of liquid;
a radiant permeable matrix burner disposed inside of the heat exchange tube at the first end, the burner including an outlet end and configured to produce hot combustion products directed from the outlet end of the burner into the heat exchange tube;
an oxidant-fuel mixer to mix an oxidant material with a fuel material to form a combustible mixture of oxidant and fuel, the oxidant-fuel mixer exteriorly disposed adjacent the first end of the heat exchange tube in oxidant-fuel mixture fluid transfer communication with the radiant burner; and
a thermally insulated insert disposed within the heat exchange tube adjacent the outlet end of the radiant burner opposite the oxidant-fuel mixer, wherein the thermally insulated insert is configured to limit heat transfer to the heat exchange tube from the combustion products directed from the outlet end of the radiant burner.

2. The process heater of claim 1 wherein the thermally insulated insert has a shape of an annular cylinder.

3. The process heater of claim 1 wherein the body of liquid comprises water.

4. The process heater of claim 1 wherein the oxidant material comprises air.

5. The process heater of claim 1 wherein the fuel material comprises natural gas.

6. The process heater of claim 1 wherein the oxidant-fuel mixer comprises a fuel injector.

7. The process heater of claim 1 wherein the oxidant-fuel mixture comprises an air to fuel ratio that is 0% up to 30% air in excess of complete combustion of the fuel.

8. The process heater of claim 1 wherein the oxidant-fuel mixture combusts within or on the surface of the permeable matrix.

9. The process heater of claim 1 wherein the radiant burner combusts the oxidant-fuel mixture to produce combustion products containing ≤10 ppm NO x and <10 ppm CO at 3% oxygen (dry basis).

10. The process heater of claim 1 wherein the radiant permeable matrix burner comprises a cylindrical shaped metal wire mesh of high temperature material.

11. The process heater of claim 1 wherein the radiant permeable matrix burner comprises a permeable metal foam matrix of high temperature material.

12. The process heater of claim 1 wherein the thermally insulated insert comprises a metal corrugated foil.

13. The process heater of claim 1 wherein the radiant permeable matrix burner comprises a permeable metal foam matrix additionally comprising a second thermally insulating insert disposed within the heat exchange tube exteriorly adjacent the permeable metal foam matrix.

14. The process heater of claim 13 wherein the second thermally insulating insert has a shape of an annular cylinder.

15. The process heater of claim 1 wherein the heat exchange tube includes a second end opposite the first end and wherein combustion products produced by the burner are discharged.

16. A method of operating the process heater of claim 1 , the method comprising:
feeding the oxidant material and the fuel material to the oxidant-fuel mixer;
mixing the oxidant material with the fuel material to form the combustible mixture of oxidant and fuel;
combusting the combustible mixture of oxidant and fuel via the radiant permeable matrix burner to produce hot combustion products; and
directing the hot combustion products into the heat exchange tube and into heat transfer communication with the body of liquid.

17. A method for processing heat, the method comprising:
introducing an oxidant material and a fuel material into an oxidant-fuel mixer disposed exteriorly adjacent a first end of a heat exchange tube, the tube including at least a first end disposed in a body of liquid contained in a tank;
mixing the oxidant material with the fuel material to form a combustible mixture of oxidant and fuel;
transferring the combustible mixture of oxidant and fuel to a radiant permeable matrix burner disposed inside of the heat exchange tube;
combusting the combustible mixture of oxidant and fuel to produce hot combustion products via the radiant permeable matrix burner disposed inside of the heat exchange tube, the heat exchange tube including a thermally insulated insert disposed therein adjacent an outlet end of the radiant burner opposite the oxidant-fuel mixer;
limiting heat transfer to the heat exchange tube from the outlet end of the radiant burner through the thermally insulated insert; and
transferring heat from the hot combustion products to the body of liquid contained in the tank via the heat exchange tube.

18. The method of claim 17 wherein the thermally insulated insert disposed within the heat exchange tube has a shape of an annular cylinder.

19. The method of claim 17 wherein the body of liquid comprises water, the oxidant material comprises air and the fuel material comprises natural gas.

20. The method of claim 17 wherein the radiant permeable matrix burner combusts the combustible mixture of oxidant and fuel to produce combustion products containing ≤10 ppm NO x and <10 ppm CO at 3% oxygen (dry basis).

Assignees

• Gas Technology Inst

Inventors

• Kozlov Aleksandr
• KALENSKY David
• Khinkis Mark
• SHMELEV Vladimir
• Nikolaev Vladimir

Classifications

• F24H1/206 Primary

  with submerged combustion chamber · CPC title

• F23D14/145

  combustion being stabilised at a screen or a perforated plate · CPC title

• F23C6/045

  with staged combustion in a single enclosure · CPC title

• F23D2203/005

  Radiant burner heads · CPC title

• F23D2203/1012

  tubular · CPC title