Sonic injection furnace

Patent metadata

Field	Value
Publication number	US-2020262732-A1
Application number	US-202016868994-A
Country	US
Kind code	A1
Filing date	May 7, 2020
Priority date	Jun 2, 2015
Publication date	Aug 20, 2020
Grant date	—

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

1 . An end-fired furnace for melting glass comprising:
an overhead burner; an oxidizer inlet duct in an upstream wall of the end-fired furnace, the inlet duct being in fluid communication with a source of oxidizer comprising 15% to 30% of oxygen; a combustion flue gas duct constructed and arranged to, in operation, receive combustion flue gases, the duct opening into the upstream wall of the end-fired furnace; and a sonic injection system comprising at least one sonic injector opening into the upstream wall or opening into the combustion flue gas duct and constructed and arranged to inject a jet of a gas at a speed at least equal to 80% of the speed of sound, said sonic injector being further configured and arranged to, in operation, inject its gas counter-current to a stream of the combustion flue gases that are heading toward the combustion flue gas duct.

2 . The furnace as claimed in claim 1 , wherein the sonic injector is configured and arranged to inject its gas at a speed that is at least 95% of the speed of sound.

3 . The furnace as claimed in claim 2 , wherein an impulse component of the sonic injection system perpendicular to the wall comprising the combustion flue gas duct is greater than 5 newtons.

4 . The furnace as claimed in claim 2 , wherein an impulse component of the sonic injection system perpendicular to the wall comprising the combustion flue gas duct is greater than 10 newtons.

5 . The furnace 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 square meters and wherein a cross-sectional area of the combustion flue gas duct is within the range extending from 0.5 to 3 square meters.

6 . The furnace as claimed in claim 1 , wherein a discharge area of the sonic injection system is within the range extending from 0.2 to 4 square centimeters.

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

8 . The furnace as claimed in claim 1 , wherein an impulse component of the sonic injection system perpendicular to the wall comprising the combustion flue gas duct is greater than 10 newtons.

9 . The furnace as claimed in claim 1 , wherein each sonic injector of the sonic injection system opens into the combustion flue gas duct or into the upstream wall at a point closer to the combustion flue gas duct than to the oxidizer inlet duct.

10 . The furnace as claimed in claim 1 , wherein each sonic injector of the sonic injection system opens at a position that is less than 1 meter from an edge of the combustion flue gas duct.

11 . The furnace as claimed in claim 10 , wherein each sonic injector opens at a position that is less than 0.5 meter from the edge of the combustion flue gas duct.

12 . The furnace as claimed in claim 1 , wherein the jet of gas comprises air.

13 . The furnace as claimed in claim 1 , wherein the sonic injection system is in fluid communication with a source of air, and wherein the jet of the gas comprises a jet of air.

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

15 . The furnace as claimed in claim 1 , wherein the sonic injection system is controllable to deliver the jet of gas of from 0.2% to 5% of a volume of oxidizer introduced by the oxidizer inlet duct.

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