Sonic injection furnace

Patent metadata

Field	Value
Publication number	US-2018170786-A1
Application number	US-201615579072-A
Country	US
Kind code	A1
Filing date	May 30, 2016
Priority date	Jun 2, 2015
Publication date	Jun 21, 2018
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 equipped with an overhead burner comprising an inlet duct for oxidizer, comprising 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 comprising at least one sonic injector for injecting a jet of a gas at a speed at least equal to 80% of the speed of sound, opening into the upstream wall or opening into the duct for receiving the combustion flue gases, said sonic injector injecting its gas counter-current to a stream of the combustion flue gases that are heading toward the duct for receiving the combustion flue gases.

2 . The furnace as claimed in claim 1 , wherein the sonic injector injects its gas at at least 95% of the speed of sound.

3 . 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 m 2 and wherein a cross-sectional area of the duct for receiving the flue gases in the upstream wall is within the range extending from 0.5 to 3 m 2 .

4 . 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 cm 2 .

5 . The furnace as claimed in claim 4 , 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 and preferably greater than 10 newtons.

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

7 . The furnace 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 flue gases.

8 . The furnace as claimed in claim 7 , wherein every sonic injector opens at less than 0.5 m from the edge of the duct for receiving the flue gases.

9 . The furnace as claimed in claim 1 , wherein the gas is air.

10 . The furnace as claimed in claim 1 , wherein the sonic injection system comprises several sonic injectors.

11 . A process for preparing molten glass comprising melting glass in the furnace of claim 1 .

12 . The process as claimed in claim 11 , wherein the sonic system delivers gas in a proportion of from 0.2% to 5% and preferably from 0.2% to 2% of the Normal volume of oxidizer introduced by the oxidizer inlet duct.

13 . The process as claimed in claim 11 , wherein the amount of oxidizer introduced into the furnace is in excess relative to the amount of fuel introduced into the furnace.

14 . The process as claimed in claim 11 , wherein the amount of oxidizer introduced into the furnace not including via the sonic injection system is in excess relative to the amount of fuel introduced into the furnace not including via the sonic injection system.

15 . (canceled)

16 . (canceled)

Assignees

• Verallia France
• Saint Gobain

Inventors

• Hayau Frédéric
• Garnier Laurent

Classifications

• C03B5/04 Primary

  in tank furnaces {(C03B5/02 takes precedence)} · CPC title

• C03B2211/30

  introducing oxygen into the glass melting furnace separately from the fuel · CPC title

• C21C2005/5223

  with post-combustion · CPC title

• C21C5/04

  Manufacture of hearth-furnace steel, e.g. Siemens-Martin steel {(C21C5/005 takes precedence)} · CPC title

• C03B5/235 Primary

  Heating the glass (C03B5/02, C03B5/18, C03B5/225 take precedence) · CPC title