Title of Invention

"AN OPENING BLOCK FOR AN OXYBURNER AND AN ASSEMBLY THEROF "

Abstract An oxyburner (1) is associated with an opening (3) comprising a through passage (2) comprising a substantially cylindrical inlet region (5) receiving the downstream end of the oxyburner (1) and a substantially cylindrical outlet region (4) of a diameter Ds and a length Ls, the ratio Ds/De being comprised between 1.5 and 2.5 and the ratio Ls/(Ds-De) comprised between 2 and 7. The speed of ejection of the oxygenated combustible gas is greater than 5 meters/second and the speed of ejection of the combustible gas is greater than the speed of the combustion-supporting gas. Application particularly to glass furnaces.
Full Text The present invention relates to an.opening block for an oxyburner The present invention also relates to oxyburners used in high temperature production furnaces, particularly glass furnaces, and more particularly an opening block for a non-cooled oxyburner of the type comprising a lock of refractory material formed with a through passage.
The openings for non-cooled oxyburners comprise most often a straight cylindrical passage, as described in U.S. patent No. 5,2 67,850 or comprise a flared outlet region, as described in U.S. patent 5,092,760. In the first case, the combustion taking place in the passage, the speed of the gases leaving the passage and entering the furnace is very high, even in the case in which the speeds of ejection of the combustible agent and of the oxygenated combustible agent are low, which is inconvenient for numerous uses, in particular in glass furnaces. In the second case, the speeds of ejection must be relatively high to cool the passage of the opening and to avoid the return of combustion gases from the furnace into this latter, which also gives rise to excessive outlet speeds.
The present invention has for its object to provide an opening for an oxyburner, and an oxyburner assembly comprising such an opening, permitting reducing the speeds of ejection of the combustible agent and of the oxygenated combustible agent, therefore to reduce the turbulence and to retard the mixing between these components, thereby permitting avoiding the formation of points of elevated temperature in the opening, which generate nitrogen oxides, to increase the luminosity of the flame to provide improved radiant heat transfer, with the speed of the gas at the outlet of the opening maintained at a relatively low level.
To do this, according to one feature of the invention, the passage of the opening comprises a substantially cylindrical outlet region of a diameter Ds and a length Ls connected to a substantially cylindrical inlet region of a diameter De, the ratio Ds/De being comprised between 1.5 and 2.5 and the ratio Ls/(Ds-De) being comprised between 2 and 7.
According to other features of the invention:
- the ratio Ds/De does not exceed 2;
- the ration Ls/(Ds/De) is comprised between 4 and 6;
- the outlet region comprises a conical upstream
portion for connection to the inlet region, having
typically a flare angle less than 45° and a length t not
exceeding about 15% of the length Ls of the outlet region.
U.S. patent No. 3,748,087 discloses an assembly of an air burner and an opening comprising a passage having a short outlet region which is very wide and a long region of small diameter to provide an intimate mixture of the combustible and combustion air at high speed and permitting a precombustion in the outlet region.
The present invention also has for its object an assembly of an oxyburner and an opening as defined above, comprising at least one internal passageway for ejection of combustible and at least one peripheral passageway for ejection of oxygenated combustible whose ends terminate in the inlet region of the opening, as well as a furnace, particularly a glass furnace, equipped with such an assembly
According to another characteristic of the invention, the internal passageway for the combustible opens at the downstream end of the inlet region, at its connection with the outlet region.
The present invention also relates to a process for using such an assembly of oxyburner and opening, in which the oxygenated combustible is ejected at a speed not less than 5 meters/second (m/s) and preferably less than 60 m/s, the combustible being ejected at a speed greater than the speed of ejection of the oxygenated combustible.
Therefore, the present invention provides for an assembly of an oxyburner (1), comprising an opening block (3) of refractory material formed with a through passage (2), characterized in that the passage (2) comprises a substantially cylindrical outlet region (4) of a diameter Ds and a length Ls, connecting to a substantially cylindrical inlet region (5) of a diameter De, the ratio Ds/De being comprised between 1.5 and 2.5 and the ratio Ls/(DS-De) being comprises between 2 and 7.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Other characteristics and advantages of the present invention will apparent from the following description of embodiments given by way of non-limiting example, with respect to the accompanying drawings, in which:
Figure 1 is a schematic view of a first embodiment of an assembly of oxyburner and opening according to the invention;
Figure 2 is a curve showing the profile of the speeds of the gas leaving the opening of the assemblies according to Figure 1; and
Figure 3 is a schematic view, analogous to Figure 1, of a second embodiment of an assembly of oxyburner and opening according to the invention.
In Figure 1, there is seen the downstream end of an oxyburner 1 extending partially into a through passage 2 of an opening 3 of refractory material and adapted to be mounted in the wall of a furnace (not shown), particularly a glass furnace.
According to the invention, the passage 2 of the opening 3 comprises a substantially cylindrical outlet region 4 of an internal diameter Ds and an axial length Ls connecting to a substantially cylindrical coaxial inlet region 5 of an internal diameter De. In the illustrated embodiment, the oxyburner 1 comprises at least one central passageway 6 for ejection of gaseous or atomized liquid combustible, coaxial to the inlet region 5 and whose forward or outlet end is substantially coplanar with the outlet plane 7 of the inlet region 5. The oxyburner 1 comprises at least one peripheral conduit 8 for the ejection of oxygenated combustible gas having an oxygen content of at least 5% received within the upstream end of the inlet region 5 and terminating in this latter, at a distance to the rear of the end 7 of the combustible passageway 6. Preferably, the outlet region 4 comprises an upstream portion 9, typically truncated conical with a half angle a and of a length 1 preferably continuously connecting, without any sharp edges, to the downstream end of the inlet region 5 and to the principal portion of the outlet region 4.
According to one aspect of the invention, the ratio of the diameters Ds and De is comprised between about 1.5 and 2.5, preferably less than about 2 and the ratio Ls/(Ds-De) of the length of the outlet region to the difference between the diameters of the inlet and outlet regions is comprised between about 2 and 7, typically between about 4
and 6. In the preferred embodiment illustrated, the angle a of the connection region 9 does not exceed 45° and the length 1 does not exceed 15% of the region Ls and the outlet region 4.
To guarantee sufficient cooling of the oxyburner/opening assembly, the outlet speed of the oxygenated combustible gas in the inlet region 5 is greater than 5 m/s and preferably does not exceed about 60 m/s. Correspondingly, the speed of ejection of the combustible at the end 7 of the passage 6 is comprised between 1 and about 6 times the speed of ejection of the oxygenated combustible gas, typically between 1.5 and 3 times this latter.
There is shown in Figure 2, the profile of the axial speeds of the combustion gases in the plane of the outlet 10 of the outlet region 4, the ordinates being the axial speed in meters/second and the abscissae the location of a point in the outlet plane determined by the region between its radius relative to the axis and the maximum radius (equal to Ds/2), with an ejection speed of natural gas of 3 0 m/s and an ejection speed of impure oxygen of 15 m/s, and with two opening geometries A and B according to the following table:

(Table Removed)
As is seen in Figure 2, the axial speed of the combustion gases at the outlet of the opening nowhere exceeds 40 m/s but remains greater than 10 m/s up to the immediate vicinity of the limit layer along the walls of the outlet region 4.
Figure 3 shows an embodiment of an oxyburner assembly according to the invention comprising at least two, typically at least three, passages 6' for ejection of
combustible, whose outlets are all coplanar, typically in the plane 7 at the outlet of the inlet region 5. Typically, the oxyburner comprises five (as shown) or seven conduits 7' angularly spaced about the axis of the inlet region 5. The multi-tube injectors have been able to be industrially developed by reason of the risks of local overheating of the opening block in the region of the regenerators adjacent the injection conduits because of the approach of these latter to the wall of the opening in comparison to the embodiment with a central conduit. The stepped cylindrical configuration of the opening according to the invention permits considerably reducing these risks. To reduce them substantially, according to one aspect of the invention, the minimum distance ^ between an internal conduit 61 and the adjacent wall of the inlet region 5 of the opening is determined as a function of the dimensions of the outlet region 4 of the opening according to the following relationship:
(Formula Removed)
comprised between 6 and 8.
This relationship expresses the fact that combustible ejected by a pipe 61 with a theoretical ejection cone with a half angle of opening of about 6°, will not strike the internal wall of the outlet region 4 but would strike a theoretical prolongation of this latter at a point located at an optimal distance from the end 10 of the opening.
Although the present invention has been described with respect to particular embodiments, it is not thereby limited but is on the contrary susceptible of modifications and variations which will be apparent to those skilled in the art, within the scope of the following claims.





CLAIM:
1. An assembly of an oxyburner (1) comprising an opening block (3) of refractory material formed with a through passage (2), characterized in that the passage (2) comprises a substantially cylindrical outlet region (4) of a diameter Ds and a length Ls, connecting to a substantially cylindrical inlet region (5) of a diameter De, the ratio Ds/De being comprised between 1.5 and 2.5 and the ratio Ls/(DS-De) being comprises between 2 and 7.
2. The assembly as claimed in claim 1, wherein the ratio Ds/De does not exceed 2.
3. The assembly as claimed in any one of claims 1 or 2, wherein the ratio Ls/(Ds-De) is between 4 and 6.
4. The assembly as claimed in any one of the preceding claims, wherein the outlet region (4) comprises a truncated conical upstream portion (9) connecting to the inlet region (5).
5. The assembly as claimed in claim 4, wherein the truncated conical portion (9) has an opening half angle not exceeding 45°.
6. The assembly as claimed in claim 5, wherein the length L of the truncated conical portion (9) does not exceed 15% of the length Ls of the outlet section (4).
7. The assembly as claimed in claim 1, wherein the said oxyburner comprises at least one internal passage (6, 6') for ejection of combustible, and at least one peripheral passage (8) for ejection of oxygenated combustible opening into the inlet region (5).
8. The assembly as claimed in claim 7, wherein the internal passage for combustible (6, 6') opens (at 7) at the downstream end of the inlet region (5).
9. The assembly as claimed in any one of claims 7 or 8, wherein it comprises two internal passages (6'), each spaced from the wall of the internal region by a distance (s) such that:
(Formula Removed)
comprised between 6 and 8.
10. Glass furnace whenever incorporated with an assembly, as claimed in any one of the preceding claims.
11. An assembly of an oxyburner substantially as herein described with reference to and as illustrated in the accompanying drawings.

Documents:

1552-del-1995-abstract.pdf

1552-del-1995-claims.pdf

1552-del-1995-complete specification (granted).pdf

1552-DEL-1995-Correspondence-Others-(16-03-2011).pdf

1552-del-1995-correspondence-others.pdf

1552-del-1995-correspondence-po.pdf

1552-del-1995-description (complete).pdf

1552-del-1995-drawings.pdf

1552-del-1995-form-1.pdf

1552-del-1995-form-13.pdf

1552-del-1995-form-2.pdf

1552-DEL-1995-Form-27-(16-03-2011).pdf

1552-del-1995-form-3.pdf

1552-del-1995-form-4.pdf

1552-del-1995-form-6.pdf

1552-del-1995-gpa.pdf

1552-del-1995-petition-137.pdf

1552-DEL-1995-Petition-138.pdf


Patent Number 193942
Indian Patent Application Number 1552/DEL/1995
PG Journal Number 36/2004
Publication Date 04-Sep-2004
Grant Date 30-Jan-2006
Date of Filing 21-Aug-1995
Name of Patentee L'AIR LIQUIDE, SOCIETE ANONYME POUR L'ETUDE ET L'EXPLOITATION DES PROCEDES GEORGES CLAUDE
Applicant Address 75 QUAI D'ORSAT, 75321 PARIS CEDEX 07, FRANCE
Inventors:
# Inventor's Name Inventor's Address
1 THIERRY DUBOUDIN 8 RUE DU LAC, 75015 PARIS, FRANCE
2 LOUIS PHILIPPE 17W 726 BUTTERFIELD RD., OAKBROOK TERRACE, IL 60181, U.S.A.
3 SERGE LAURENCEAU 23 RUE CHAMPS LAGARDE, 5 RESIDENCE DE LA PEPINIERE, 78000, VERSAILLES, FRANCE
4 ERIC DUCHATEAU 211 COE ROAD, CLARENDON HILLS, IL 60514, USA
5 JEAN-YVES IATRIDES 19-21 RUE BOURDINGNON, 94100 ST MAUR DES FOSSES, FRANCE
PCT International Classification Number F23D 14/22
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 94 11332 1994-09-22 France