Sonic injection furnace

Patent metadata

Field	Value
Publication number	US-10683225-B2
Application number	US-201615579072-A
Country	US
Kind code	B2
Filing date	May 30, 2016
Priority date	Jun 2, 2015
Publication date	Jun 16, 2020
Grant date	Jun 16, 2020

Abstract

A low-NOx end-fired furnace for melting glass equipped with an overhead burner includes an inlet duct for oxidizer, including 15% to 30% of oxygen, in its upstream wall, a duct for receiving the combustion flue gases in its upstream wall, and a sonic injection system including at least one injector for injecting a jet of a gas at a speed at least equal to 80% of the speed of sound, referred to as a sonic injector, opening into the upstream wall or opening into the duct for receiving the combustion flue gases, the sonic injector injecting its gas counter-current to the stream of the combustion flue gases that are heading toward the duct for receiving the combustion flue gases.

First claim

The invention claimed is:

1. A process for preparing molten glass comprising:
melting glass in an end-fired furnace, the end-fired furnace equipped with (i) an overhead burner comprising an inlet duct for oxidizer, comprising 15% to 30% of oxygen, in an upstream wall of the end-fired furnace, (ii) a duct for receiving combustion flue gases, the duct opening into the upstream wall, and (iii) a sonic injection system comprising at least one sonic injector opening into the upstream wall or opening into the duct for receiving the combustion flue gases, and
injecting by said at least one injector a jet of a gas at a speed at least equal to 80% of the speed of sound, said at least one sonic injector injecting the jet of gas so that the jet of gas is counter-current to a stream of the combustion flue gases that are heading toward the duct for receiving the combustion flue gases.

2. The process as claimed in claim 1 , wherein the sonic system delivers gas in a proportion of from 0.2% to 5% of a Normal volume of oxidizer introduced by the oxidizer inlet duct.

3. The process as claimed in claim 2 , wherein the sonic system delivers gas in a proportion of from 0.2% to 2% of the Normal volume of oxidizer introduced by the oxidizer inlet duct.

4. The process as claimed in claim 1 , wherein an amount of oxidizer introduced into the furnace is in excess relative to an amount of fuel introduced into the furnace.

5. The process as claimed in claim 1 , wherein an amount of oxidizer introduced into the furnace not including via the sonic injection system is in excess relative to an amount of fuel introduced into the furnace not including via the sonic injection system.

6. The process as claimed in claim 1 , wherein the speed of the jet of gas is at least 95% of the speed of sound.

7. The process as claimed in claim 1 , wherein an impulse component of the sonic injection system perpendicular to the wall comprising the duct for receiving the combustion flue gases is greater than 5 newtons.

8. The process as claimed in claim 7 , wherein the impulse component of the sonic injection system perpendicular to the wall comprising the duct for receiving the combustion flue gases is greater than 10 newtons.

9. The process as claimed in claim 1 , wherein the gas of the jet of gas is air.

10. The process as claimed in claim 1 , wherein a cross-sectional area of the oxidizer inlet duct in the upstream wall is within the range extending from 0.5 to 3 m 2 and wherein a cross-sectional area of the duct for receiving the combustion flue gases in the upstream wall is within the range extending from 0.5 to 3 m 2 .

11. The process as claimed in claim 1 , wherein a discharge area of the sonic injection system is within the range extending from 0.2 to 4 cm 2 .

12. The process as claimed in claim 1 , wherein every sonic injector of the sonic injection system opens into the duct for receiving the combustion flue gases or into the upstream wall at a point closer to the duct for receiving the combustion flue gases than to the oxidizer inlet duct.

13. The process as claimed in claim 1 , wherein every sonic injector of the sonic injection system opens at less than 1 m from an edge of the duct for receiving the combustion flue gases.

14. The process as claimed in claim 13 , wherein every sonic injector opens at less than 0.5 m from the edge of the duct for receiving the combustion flue gases.

15. The process as claimed in claim 1 , wherein the sonic injection system comprises a plurality of sonic injectors.

Assignees

• Verallia France
• Saint Gobain

Inventors

• Hayau Frédéric
• Garnier Laurent

Classifications

• F27D17/20

  Arrangements for treatment or cleaning of waste gases · CPC title

• C21C2005/5223

  with post-combustion · CPC title

• Y02P40/57

  Improving the yield, e-g- reduction of reject rates · CPC title

• C21C5/5217

  equipped with burners or devices for injecting gas, i.e. oxygen, or pulverulent materials into the furnace · CPC title

• C03B5/237 Primary

  Regenerators or recuperators specially adapted for glass-melting furnaces · CPC title