CN110963673B

CN110963673B - Self-cooling submerged burner and glass kiln comprising same

Info

Publication number: CN110963673B
Application number: CN201911310233.0A
Authority: CN
Inventors: 阎韬; 瑞米·奇亚瓦; 张婷
Original assignee: Air Liquide China R&d Co ltd
Current assignee: Air Liquide China R&d Co ltd
Priority date: 2018-12-19
Filing date: 2019-12-18
Publication date: 2022-07-12
Anticipated expiration: 2039-12-18
Also published as: CN110963673A

Abstract

The invention discloses a self-cooling submerged burner and a glass kiln comprising the same. In the event that the submerged burner is out of service, it is also possible to avoid the submerged burner being deactivated by clogging with glass melt.

Description

Self-cooling submerged burner and glass kiln comprising same

Technical Field

The invention relates to a submerged burner for a glass kiln, in particular to a self-cooling submerged burner and a glass kiln comprising the same.

Background

In the glass industry, Submerged Combustion melters (Submerged Combustion melters) may be used to produce molten glass from raw glass materials, wherein fuel and oxidant are introduced directly into the melt from the bottom thereof, primarily through Submerged burners (Submerged burners), and Combustion products may be passed through the melt from bottom to top after Combustion of the fuel and oxidant has taken place. When the glass is immersed and combusted, the flame directly contacts with the glass melt, so that the heat transfer effect is better; the high flow rate of combustion products generated by the oxidant and the fuel enters the glass melt, and the gas expands in the immersion combustion process, so that the glass raw materials are quickly melted and generate a large amount of turbulence, and the molten glass can obtain a uniform mixing effect more easily.

In the conventional submerged combustion process, if air is used as the source of the oxidizing agent, nitrogen released during the combustion process acts as an inert gas which does not participate in the reaction, and tends to cause occlusion or inclusion of blister components in the glass melt. Generally, the problem of ash bubble occlusion can be effectively solved by using pure oxygen as an oxidant, but the new problems brought by the pure oxygen are that the flame temperature of the pure oxygen combustion is too high, the metal nozzle of the combustor is corroded and damaged too fast, and the pure oxygen cannot be compensated or replaced. Because the submerged burner is submerged in the glass melt, its quality, placement and operational control requirements are critical, and in the event of a failure, when the zone temperature is out of control or the pressure within the burner is too low, some of the glass melt and/or solid raw materials enter the submerged burner and solidify, coat or partially coat the inner walls of the burner nozzle, restricting the flow of oxidant/fuel, and possibly causing nozzle plugging. In addition, when the glass melt is submerged to a depth within the nozzle of the burner, if the fuel/oxidant impulse within the nozzle is insufficient, the flame will not enter the glass melt and will be ejected from the adjacent refractory material.

Improvements in the prior art for submerged combustion have focused on how to promote more efficient heat transfer. U.S. patent application No. 2016060154A discloses a burner for submerged combustion melting in which fuel and oxidant are premixed prior to entry into the glass melt, the mixture exiting the nozzle is ignited to produce a flame, the flaring of the flame causes the momentum of the combustion gases to spread more horizontally in the glass melt, reducing the vertical velocity and momentum of the combustion gases traveling through the glass melt with the aim of avoiding loss of combustion heat to areas other than the glass melt, promoting more efficient heat transfer in submerged combustion systems. However, the burner must accurately balance the orifice size of the nozzle outlet and the flow rates of the fuel and oxidant in each channel to enable the combustion flame at the outlet to transfer heat to the glass melt in a timely manner, or burn back to the interior of the nozzle and channels is likely to occur.

US patent US9731990B discloses a submerged combustion glass making system comprising one or more submerged burners which discharge combustion products including water vapour at the level of the material being melted in the melter and creating turbulent conditions in the material, a fluid cooled refractory material and optionally a metal housing, or the metal housing may include coolant channels. One or more conduits remove water from the water vapor from the substantially water saturated refractory region and/or the burner supports to increase the useful life of the burner.

Above-mentioned submerged combustion ware that adopts among the prior art all needs to submerge in the melting environment that high temperature and corrosivity are strong more than 1000, and the tempering not only takes place easily for the submerged combustion ware that the combustion degree is violent to very easily corrosion damage can set up a powerful cooling system and cool down for the combustor generally, thereby reduces or avoids the combustor to damage, if cooling system is unavailable, metal parts among the submerged combustion ware can't bear such high temperature, and very high safety risk will appear in the system. In the prior art, the immersed burner cooled by cooling liquid not only wastes fuel and/or oxidant energy greatly, but also a gas channel inside the burner is easy to block, so that great equipment failure risk and potential safety hazard exist.

In view of the above, a need exists in the art for a self-cooling submerged burner and a glass furnace including the same, which overcome the above-mentioned drawbacks and deficiencies of the prior art.

Disclosure of Invention

According to the technical scheme disclosed by the invention, the structural design of the immersion burner can effectively prevent the problems that the impulse force of the nozzle is insufficient and the combustion flame is sprayed out from the refractory materials at two sides due to excessive immersion nozzles of the glass melt/glass raw material in the melting tank; since most of the area of the submerged burner is not wetted by the glass melt, the use of cooling medium is reduced, even without the need for special cooling devices. The porous terminal part is arranged in the nozzle head area, so that the risk of blockage caused by wetting the nozzle with the glass melt can be reduced, and the service life of the burner, particularly the burner nozzle, can be prolonged; meanwhile, the problems that the burner nozzle is eroded too fast and cannot be maintained or replaced due to overhigh flame temperature in the submerged combustion process are avoided; and ensures that the combustion flame of the fuel and the oxidant can transfer heat to the glass melt as soon as possible, and the combustion heat is sufficient. The burner can also be prevented from being scrapped and stopped due to blockage of the glass melt during the stop of the operation of the submerged burner.

A first aspect of the invention relates to a submerged burner comprising a first fluid conduit, a second fluid conduit and a porous end fitting, wherein,

the first fluid conduit has a first inlet end and a first outlet end for providing a first fluid;

the second fluid conduit having a second inlet end and a second outlet end for providing a second fluid;

the porous end fitting having a porous inlet end, M first cell channels through the porous inlet end and the first fluid outlet and M first fluid outlets, N second cell channels through the porous inlet end and the second fluid outlet, and N second fluid outlets, wherein,

the porous inlet end is directly connected with a first outlet end and a second outlet end respectively, and the M first fluid outlets and the N second fluid outlets respectively supply a first fluid or a second fluid to a molten environment outside the submerged burner, so that the first fluid and the second fluid are mixed and combusted in the molten environment; alternatively, the first and second electrodes may be,

the submerged burner also comprises a mixing chamber, the openings of the porous inlet end, the first outlet end and the second outlet end face the mixing chamber, after the first fluid and the second fluid form a premix in the mixing chamber, the premix, the first fluid and/or the second fluid are sprayed into the porous inlet end and finally supplied to a melting environment outside the submerged burner through the first fluid outlet and the second fluid outlet, and combustion occurs;

wherein the first and/or second channel has an equivalent diameter in the range of 0.8mm to 6mm, preferably 1mm to 5mm, and the first and/or second channel has an equivalent diameter, shape and distribution configured such that melt in the molten environment cannot freely penetrate into the first and second channel within the operating temperature range of the molten environment.

Further, the term "not freely infiltrate" means that the infiltration depth of the melt in the melting environment into the porous terminal part is less than a preset value H.

Further, the porous terminal member has a concave end in an inverted conical shape.

Further, the first fluid outlet and/or the second fluid outlet is formed to extend from the center of the depressed end to the periphery.

Further, the preset value H of the infiltration depth ranges from 0 to 15mm, preferably from 5mm to 10 mm.

Further, the depth of the first pore canal and/or the second pore canal is more than or equal to 25 mm. The first and/or second cells herein are of a depth and volume configuration throughout the interior of the porous end member that not only facilitates upward diffusion of the fuel/oxidant, but also effectively prevents burner plugging by melt infiltration in the molten environment.

Further, the equivalent diameters of the first and second cells range from 1.5mm to 4mm, preferably from 2mm to 3.5mm, respectively. The cross-sectional shapes of the first cell and the second cell are not particularly limited in the present invention, but all of the cells preferably have the same shape, and more preferably all of the cells have a cylindrical shape with a uniform wall thickness, in consideration of workability, material strength, corrosiveness of the melt, and the like.

Further, one of the M first cell channels has an equivalent diameter different from the other.

Further, one of the N second cell channels has an equivalent diameter different from the other.

Further, the cross-sectional shapes of the first fluid outlet and the second fluid outlet are respectively: triangular, circular, elliptical, quadrilateral, quadrilobal or sinusoidal. In the present invention, the cross-sectional shapes of the first fluid outlet and the second fluid outlet are not particularly limited, but in consideration of workability, material strength, corrosiveness of the melt, and the like, it is preferable that all the positions of the fluid outlets have the same shape, and it is more preferable that all the positions are circular.

Further, the first cell channels form an angle of 0 ° to 45 ° with respect to a central axis direction of the porous terminal member.

Further, the second port channel forms an angle of 0 ° to 45 ° with respect to the central axis direction of the porous end fitting, and/or the central axis direction of the first port channel and/or the second port channel is parallel to the central axis direction of the submerged burner. In the present invention, the inclination angles of the first port and the second port with respect to the central axis of the burner are not particularly limited, and it is preferable that both the first port and the second port are arranged vertically upward in view of easy workability, reduction of turbulence of the melt, and the like.

Further, the convergence angle of the first and second fluid outlets toward or away from each other ranges from 0 ° to 90 °.

Further, the hole pitch of the first hole channel and the second hole channel is respectively greater than or equal to 2 times and less than or equal to 10 times of the hole channel diameter. The hole spacing herein may refer to a distance between two adjacent first holes, two adjacent second holes, or between two adjacent first holes and second holes, and the proper hole spacing may ensure proper distribution of diffusion of the fuel and/or the oxidant, and at the same time, prevent hole wall deformation caused by too tight arrangement of the holes under high temperature conditions.

Further, the material of the porous terminal member is selected from any one or a combination of two or more of zirconia, alumina, silica, metal carbide, boride, nitride, silicide, electrofused silicon, titanium nitride, zirconium nitride, and a composite thereof.

Further, the second fluid conduit is disposed coaxially with the first fluid conduit.

Further, the second fluid conduit is positioned within the first fluid conduit and defines an annular space therebetween.

Further, N ═ M, and N and M are each a positive integer equal to or greater than 1.

Further, one of the first and second fluids is an oxidant stream and the other is correspondingly a fuel stream.

Further, the oxidant is pure oxygen or air.

Further, the air is oxygen-enriched air.

Further, the fuel is selected from any one or a combination of more than two of hydrogen, natural gas, propane or other hydrocarbon compounds.

A second aspect of the present invention is directed to a melter system comprising:

a melting chamber containing a melt therein, the melting chamber having a melt therein,

a feed end and a discharge end for feeding raw materials into the melting chamber,

one or more submerged burners according to the first aspect of the invention defined in the melting chamber for injecting a flame into the melt. The melter can be completely supplied with heat by adopting a submerged burner, and can also be used by combining the submerged burner with other heat supply modes.

A third aspect of the invention relates to a self-cooling submerged burner for a glass kiln, comprising: a first fluid conduit having an inlet end and an outlet end for passage of a first fluid; a second fluid conduit within the first fluid conduit having an inlet end and an outlet end for passage of a second fluid; one of the first and second fluids is an oxidant stream and the other is correspondingly a fuel stream; a porous end fitting having an inlet end connected to the outlet end of the first fluid conduit and the outlet end of the second fluid conduit, respectively, the first and second fluids not contacting before flowing out of the outlet end of the porous end fitting; the porous terminal part is provided with a plurality of pore channels which penetrate through the inlet end and the outlet end of the porous terminal part, and the diameters of the pore channels are 0.3 mm-10 mm; wherein the channel size, shape, and channel distribution are configured such that the glass melt cannot freely penetrate the channel within an operating temperature range of the glass furnace.

Further, there is a spacer member between all of the cells through which the first fluid flows and all of the cells through which the second fluid flows.

The present invention also relates in a fourth aspect to a glass furnace comprising a furnace wall defining a combustion chamber, at least one submerged combustion port, a feed inlet, a discharge outlet, and a burner according to any of the preceding aspects arranged in the vicinity of an edge of the at least one combustion port.

Compared with the prior art, the technical scheme provided by the invention has the following advantages:

1. the invention provides a self-cooling submerged burner easy to maintain, which utilizes a porous terminal part at a nozzle end of the submerged burner, selects the porous terminal part with proper pore canal diameter and pore canal distribution in an operating pressure and temperature interval in a melting environment, can control the infiltration depth of molten glass in the submerged burner in an extremely low range, prevents the submerged burner from being corroded by glass melt and eroded by a high-temperature environment, prolongs the service life of the submerged burner, greatly reduces the consumption of a refrigerant/cooling medium required by a cooling system of the submerged burner, and even does not need to arrange a special cooling device under proper conditions.

2. The self-cooling submerged burner provided by the invention can keep the gas path smooth even if no fuel/oxidant is supplied after the combustion is stopped, and effectively prevent glass melt from permeating into the pore channels of the burner to block the burner.

3. The invention can also introduce refrigerant gas through the oxidant runner to cool the combustor and improve the safety coefficient in case of emergency.

4. The submerged burner is particularly suitable for gas fuel, particularly hydrogen fuel, can reduce the emission of carbon dioxide in the combustion process, and the generated water can absorb other gases decomposed in glass, thus being easy for refining the glass and improving the quality of the glass.

The invention is further illustrated in the following figures and detailed description. However, these drawings and specific embodiments should not be construed as limiting the scope of the invention, and modifications readily ascertainable by those skilled in the art would be included within the spirit of the invention and the scope of the appended claims.

Drawings

The invention, together with its objects, advantages, features and related aspects, will be best understood from the following description taken in conjunction with the accompanying drawings. The figures are generally schematic and are not drawn to scale for the sake of clarity. All figures share the same reference numerals for the same or corresponding features.

Fig. 1a shows the state of wetting of a glass melt with different solid materials at a wetting angle θ <90 °.

FIG. 1b shows the state of wetting of the glass melt at wetting angles θ > 90 ° with different solid materials.

Fig. 2a-2c show top views of a porous end fitting comprising a submerged burner according to a first embodiment of the invention.

Fig. 3 shows a longitudinal section of a submerged burner comprising a first embodiment of the invention.

Fig. 4a and 4b show longitudinal cross-sectional views of a porous end fitting of a submerged burner comprising a second embodiment of the invention.

FIG. 5 shows a top view of a recessed end of a porous end member comprising embodiment two of the present invention.

FIG. 6 shows a perspective view of a recessed end of a porous end fitting that includes a second embodiment of the present invention.

FIGS. 7a and 7b show schematic views of the infiltration process of a porous end member comprising embodiment two of the present invention.

Fig. 8 shows a longitudinal sectional view of a submerged burner comprising a third embodiment of the invention.

Wherein 1 is a porous end member, 2 is a first pore channel, 3 is a second pore channel, 4 is a spacer member, 5 is a first fluid outlet or a second fluid outlet, 6 is a first inlet end, 7 is a spare gas inlet, 8 is a second inlet end, 9 is a first fluid conduit, 10 is a second fluid conduit, 11 is a temperature sensor, 12 is a UV flame monitor, 13 is a pressure sensor, 14 is a recessed end, and 15 is a mixing chamber.

Detailed Description

Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it is to be understood that the present invention is not limited to such an embodiment described below, and the technical idea of the present invention may be implemented in combination with other known techniques or other techniques having the same functions as those of the known techniques.

In the following description of the embodiments, for purposes of clearly illustrating the structure and operation of the present invention, directional terms are used, but the terms "front", "rear", "left", "right", "outer", "inner", "outward", "inward", "axial", "radial", and the like are to be construed as words of convenience and are not to be construed as limiting terms.

In the following description of the specific embodiments, it is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings for convenience in describing the invention and to simplify the description, but are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be construed as limiting the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically stated otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or may be in communication within two elements or in interactive relationship between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Unless clearly indicated to the contrary, each aspect or embodiment defined herein may be combined with any other aspect or embodiments. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature indicated as being preferred or advantageous.

As used herein, the terms "submerged burner", "burner tip" are used interchangeably and have the same meaning and, when used for submerged combustion, are to be understood as a burner constructed in the following manner: the flames they produce or the combustion gases emitted by these flames are generated in the body of material undergoing conversion. For example, the operating principle of furnaces with submerged burners for melting glass is known and has been described in particular in patents WO 99/35099 and WO 99/37591, including: the combustion takes place directly in the mass of vitrifiable material to be melted by injecting a fuel (generally a natural gas-like gas or hydrogen) and an oxidant (generally air or oxygen) through a burner located below the level of the melt. Such submerged combustion causes intense convective stirring of the molten material, thereby allowing the melting process to proceed rapidly.

As used herein, the term "nozzle" refers to a component that is located at the end of a combustor and that provides fuel and oxidant for combustion to occur.

As used herein, the terms "melt" and "melt" both refer to a substance that may include inorganic compositions, metals, or organic compositions obtained after melting, and may also be molten glass, molten metals, molten resins, molten solid waste, and the like.

As used herein, the term "glass melt" refers to a composition for making a glass article that can exist in any state between substantially solid and substantially liquid, including substantially solid and substantially liquid, such states being between a raw material and a molten glass (including a raw material and a molten glass), including any degree of partial melting between a raw material and a molten glass. As used herein, "molten glass" refers to a molten liquid material composed of an inorganic oxide material that, when cooled, is capable of forming a glass, which may also be referred to as a glass melt or simply a "melt". It is to be understood that glass is generally understood to include materials in an elastic state, and that while the molten material produced by the melter is not true glass at this time, the glass can be formed upon cooling, and those skilled in the art of glass making will understand the use of the above terms.

As used herein, the terms "melt," "melting operation," "melting process" include operations in which a glass melt is heated from a substantially solid state to a substantially liquid state to convert the raw materials into molten glass.

As used herein, the term "equivalent diameter" refers to the diameter of a circle equal to a certain cross-sectional area of the outer shape.

As used herein, the term "fuel" refers to gaseous, liquid, or solid fuels that may be used in place of or in combination with each other. If it is at least partly in gaseous form, it can be introduced directly into the submerged burner. If in liquid or solid form, is introduced in the vicinity of the submerged burner. The gaseous fuel may be natural gas (primarily methane), propane, hydrogen or any other hydrocarbon compound and/or sulphur-containing compound. The solid or liquid fuel may be essentially any compound in a carbon-and/or hydrocarbon-and/or sulphur-containing form. The manner of introduction of the gaseous fuel, liquid fuel or solid fuel can be determined by one skilled in the art as desired and the present invention is not intended to be limited in any way.

As used herein, "free penetration" refers to penetration of a melt into the channels of the porous end member of the self-cooling submerged burner of the present invention to a depth in excess of 8 times the equivalent diameter D of the channels at the operating temperature and pressure of the melting environment. The cell diameters and arrangement of the porous end members are such that as little melt as possible collects in the molten environment in the submerged burner, preventing coating and solidification of the glass melt and/or solid raw materials on the inner wall of the burner nozzle, thereby minimizing the potential for plugging of the submerged burner. Therefore, even under the condition of not externally connecting any cooling medium, the submerged burner can stably operate and cannot be corroded or blocked by melt in a melting environment. It is to be noted that the use of a usual cooling assembly is not excluded here, and the skilled person can provide at least one duct system allowing the circulation of a cooling fluid inside it, as desired, better cooling all the areas affected by the molten environment where insulation and fire resistance are required.

As used herein, "infiltration depth" refers to the extent to which the melt/melt extends from the melt environment into the interior of the burner nozzle under the influence of ambient pressure, gravity and surface tension, and may be expressed in terms of the height within which the melt/melt continues to descend after infiltrating the burner. The "depth" herein may refer to the vertical distance between the plane of a certain fluid outlet of the porous end member (e.g., the lowest of all fluid outlets in vertical distance) and the deepest wetting point within the first and/or second channel.

As used herein, the term "axial" refers to a direction of the axis of rotation, axis of symmetry, or centerline that is generally parallel to the direction of the central axis of the porous end member. The term "radial" may refer to a direction or relationship relative to a line extending perpendicularly outward from a shared centerline, axis, or similar reference. For example, two concentric and axially overlapping cylindrical components may be considered to be "radially" aligned over axially overlapping portions of the components, but not "radially" aligned over non-axially overlapping ones of the components. In some cases, these components may be considered "radially" aligned even though one or both of the components may not be cylindrical (or otherwise radially symmetric). Furthermore, the terms "axial" and "radial" (and any derivatives thereof) may encompass directional relationships (e.g., tilt) other than exact alignment with the true axial and radial dimensions, provided that the relationship predominates in the respective nominal axial or radial direction.

As used herein, the operating temperature of a glass furnace is typically as high as 1300 ℃ or higher.

In the following examples of the present invention, a glass melt is taken as an example.

Glass is an amorphous inorganic material, and the glass melt has high viscosity and strong corrosivity. The temperature of the molten glass is generally 1200 ℃ or higher. The particles on the surface of the molten glass are moved toward the inside of the melt by the internal particles, and therefore, the molecules on the surface layer of the molten glass tend to move toward the inside, thereby reducing the surface area of the liquid. The force present on the surface of the liquid, which tensions the liquid surface, is therefore called the surface tension. There are many ways to calculate the surface tension, such as calculating according to the Laplace equation, in terms of force per unit length in N/m, or in terms of energy per unit area in J/m²For example, the surface tension of silicates is generally (2.20-3.80) × 10^-1Within the range of N/m, the metal is 3-4 times larger than water and larger than molten salt, and is similar to molten metal. All factors influencing the acting force between particles directly influence the surface tension, and the main factors influencing the surface tension comprise the nature of glass, the nature of a solid contact phase, the nature of a gas contact phase, temperature, pressure and the like. Surface tension affects the wettability of a glass melt to a solid surface, which can be measured by the wetting angle of molten glass to a solid material (e.g., a metal material), with the greater the wetting angle, the greater the resistance to wetting; too small a wetting angle can result in glass flooding.

FIGS. 1a and 1b show schematic views of the wetting angle θ of a glass melt with different solid materials, where σ (s/g), σ (s/l), and σ (l/g) are balanced as shown in the Young's equation (wetting equation) of equation (1):

F＝σ(l/g)×cosθ＝σ(s/g)-σ(s/l) (1)

in the formula: f is infiltration tension; theta is a wetting angle; σ (l/g) is the liquid-gas interfacial tension; σ (s/g) is the solid-gas interfacial tension; σ (s/l) is a solid-liquid interfacial tension. If theta is 0 DEG, the glass melt is completely wetted with the solid. If θ is 180 °, it means that the glass melt is not able to wet the solid at all. As shown in fig. 1a, when the wetting angle θ of the glass melt on the surface of the solid material is acute (less than 90 °), the wetting action of the glass melt, i.e., the molten glass, on the solid surface is good, and a spreading (Spread) action is generated, and the liquid is convex lens-shaped on the solid surface, which means that the glass melt can wet the solid. As shown in fig. 1b, when the wetting angle of the glass melt on the solid material surface is obtuse (greater than 90 °), the molten glass cannot generate stretching (Spread) action on the solid material surface, so that the glass melt and the solid material (such as the nozzle material) are bonded poorly, and the liquid is in an ellipsoidal shape on the solid surface, which means that there is no wetting at the two interfaces.

Since the viscosity of the glass melt significantly changes with the temperature change, when the temperature is high (for example, 1300 ℃ or higher), and the glass is in a molten state, the viscosity of the glass melt is low, and is substantially 10Pa · S or less, the surface tension thereof is small, the spreading degree on the surface of the solid material is large, the wetting angle thereof is small, and the wettability thereof on the surface of the solid material is better, and the glass easily penetrates into the pores. Typically, in an oxygen or air medium environment, the wetting angle is between 3 ° and 8 °. When the combustion is partially or completely stopped, the temperature of the glass melt around the nozzle is rapidly reduced, and when the temperature is reduced to about 900 ℃, the viscosity of the glass melt is increased to about 100Pa S, and the glass melt gradually infiltrates into the pore channels at the end part of the burner, at the moment, the surface tension of the glass melt is rapidly increased, the spreading degree of the glass melt on the surface of a solid material is reduced, and the wetting angle is increased and is generally increased to more than 20 degrees. When the temperature of the glass melt is reduced to about 700 ℃, the glass melt is substantially solidified.

For the submerged burner of the present invention, in order to control the glass melt not to freely penetrate into the pore channels of the burner, control the infiltration depth within an extremely low range, and reduce the corrosion of the glass melt to the burner nozzle material, it is necessary to reduce the infiltration effect of the glass melt to the burner nozzle material, and ensure the infiltration between liquid and solid is controlled. However, due to the multiple limitations of the channel diameter, the burner specifications, etc., sufficient channel space cannot be provided to infinitely produce the largest possible wetting angle of the glass melt on the nozzle surface, and at this time, the nozzle is often severely blocked and the gas flow cannot be kept open. Therefore, it is necessary to calculate and combine empirical data to obtain surface tension, wetting angle, wetting depth range allowed by the burner not to be clogged, and the like of the molten glass according to the material characteristics of the nozzle, the parameters of the nozzle opening, the conditions of the peripheral refractory material and the cooling/heat dissipation characteristics thereof, the characteristics of the glass melt, the melting temperature, the melting pressure, the wetting depth, the flow rate of the fuel flow and the oxidant flow, and the like, so that the size, shape, and distribution of the cells of the porous end part can be determined.

The following examples of the invention select solid materials that meet the following criteria to form the porous end member of the submerged burner, particularly where the exit and inner walls of the channels, etc. may be in direct contact with the glass melt.

Example 1

Taking a plan view of the porous end member of the burner shown in fig. 2a as an exemplary illustration of the present embodiment, fig. 3 shows a schematic structural view of the submerged burner according to the present embodiment.

In fig. 2a, the porous end member 1 has a circular cross section, the first channels 2 can be channels for an oxidant, the second channels 3 can be channels for a fuel, and all oxidant channels and all fuel channels are separated by a spacer member 4. The present invention is not intended to limit the cross-sectional shape of the porous end member, and those skilled in the art can set the cross-sectional shape as desired, for example, a rectangular cross-section as shown in fig. 2b, and the channels corresponding to the left and right rectangular portions outside the porous end member are channels for the oxidant, and the channel corresponding to the middle rectangular portion is a channel for the fuel. Also for example, a rectangular cross-section may be provided as shown in FIG. 2c, with the central rectangular portion of the porous end fitting being the fuel passage and the annular passage defined by the outer rectangular and central rectangular locks being the oxidant passage.

Fig. 3 shows a longitudinal sectional view of a submerged burner according to the present embodiment, which comprises the following parts: a porous end piece 1, a first channel 2 for conveying a first fluid and a second channel 3 for conveying a second fluid within the porous end piece, and a spacer member 4 between the first channel 2 and the second channel 3. The porous end fitting has a first or second fluid outlet 5; the first fluid conduit 9 has a first inlet end 6, the first outlet end of which is connected to the porous inlet end of the porous end fitting 1; the second fluid conduit 10 has a second inlet end 8, the second outlet end of which is connected to the porous inlet end of the porous end fitting 1; also disposed within the burner are a temperature sensor 11, a UV flame detection sensor 12 and a pressure sensor 13 upstream of the porous end member for monitoring temperature, flame conditions, pressure during combustion. The submerged combustion burner also has a standby gas circuit which enters the first fluid conduit 9 (the oxidizer circuit in this embodiment) through the standby gas inlet 7, and may be nitrogen as the standby gas. When the oxidant and the fuel gas are normally supplied, the standby gas is in a cut-off mode, and a check valve (not shown in fig. 3) is arranged on the pipeline to prevent the oxidant gas from flowing back to the standby gas circuit; when the combustion is abnormal, the UV flame detection sensor sends the detected signal to the control system; the control system sends a signal for opening the one-way valve according to a set mode, and nitrogen with certain pressure and flow is delivered into the combustor to serve as protective gas. Even if the combustion is stopped for a long time, the operation is resumed, and the combustion can be resumed promptly. The temperature sensor 11 and the pressure sensor 13 output temperature and pressure signals, respectively, to a control system that can be used to monitor burner erosion and plugging conditions for control adjustments.

The porous terminal member 1 in this embodiment is made of an oxide ceramic containing zirconium/aluminum oxide as a main component, wherein the zirconia component is more than 23%, the alumina component is more than 70%, and the rest components are silicon oxide, titanium oxide, and a small amount of iron oxide, calcium oxide, and the like. The cross sections of the first pore canal and the second pore canal are circular, the cross section diameters are both 1.8mm, the distance between every two first pore canals and the distance between every two second pore canals are 3.6mm, the depth of every two first pore canals and the depth of every two second pore canals are 300mm, the outer wall of the porous terminal part is made of platinum-rhodium alloy with the thickness of 2mm, and a spacing part 4 made of platinum-rhodium alloy with the thickness of 2mm is used for separating a first fluid pipeline, namely a pipeline through which oxidant flows, and a second fluid pipeline, namely a pipeline through which fuel gas flows.

Example 2

This example illustrates another embodiment of the porous end fitting with reference to fig. 4a-4b, fig. 5 and fig. 6. the material composition, the depth, pore size and spacing of the first and second channels of the porous end fitting of this example are the same as those of example 1.

FIGS. 4a and 4b show longitudinal cross-sectional views of another porous end member. The porous end fitting has a relatively semi-closed concave end 14, the entire concave end 14 being formed by the outer wall at the burner nozzle, in the shape of an inverted cone. The first cells 2 and/or the second cells 3 extend through the porous inlet end and the first/second fluid outlet 5. The first and

second cell channels

2, 3 are provided inside the porous end fitting, either vertically upwards (fig. 4a) or at an angle to the central axis of the porous end fitting (fig. 4 b).

Fig. 5 shows a top view of a recessed end, at which the first and/or second fluid outlet end opens at the conical surface, the opening direction being towards the center of the recess. The distance and the arrangement mode of the first fluid outlet and the second fluid outlet and the distance and the inclination angle of the first pore channel/the second pore channel can be correspondingly adjusted. As shown in fig. 6, the arrangement of the respective first fluid outlets and/or second fluid outlets is enlarged in a conical shape formed to extend from the center to the periphery of the depressed end.

The operation of the submerged burner of the present invention to achieve a self-cooling function will be described with reference to fig. 7a and 7b, using the submerged burner with the above-described porous end fitting as an example.

Firstly, a mixed heating glass furnace is provided, wherein the immersed combustion heat supply accounts for more than 60 percent, and soda-lime silicate glass is melted. The depth of the glass melt is 1200mm, the oxidant is pure oxygen, and the fuel is natural gas, namely, the nozzle structure of the submerged burner comprises a central natural gas pipeline and a peripheral oxygen pipeline. The gas pressure of pure oxygen and natural gas is controlled at about 25 kPa. As shown in fig. 7a, at a melting temperature of the soda-lime-silicate glass of about 1320 ℃, the viscosity of the glass melt at this temperature is 10Pa · S, and natural gas and oxygen gas are kept at appropriate jet velocities, and the glass melt flows stably and is not easily infiltrated.

As shown in FIG. 7b, when the viscosity of the glass melt increases, or when the distribution of the submerged burners in the glass furnace needs to be adjusted, or when the heating mode of the partially submerged burners needs to be adjusted to be stopped, the temperature of the glass melt around the nozzle outlet of the partially submerged burners rapidly decreases, the porous end part is infiltrated, the molten glass gradually infiltrates, and the infiltration angle is theta₁To theta_nThe infiltration depth H is changed continuously.

The diameter of the circular cross section of the first pore canal and the second pore canal is set as 1.8mm, the distance between the pore canals is set as 3.6mm, and the average depth of the pore canals is 30 mm. At this point, the final depth of immersion of the porous end member with the glass melt is much less than the depth of immersion that is highly likely to cause clogging of the immersion burner. And under the condition that no external water cooling sleeve or cooling water is sprayed, tests are respectively carried out after 24 hours, 48 hours and 72 hours, the supply of natural gas and oxygen is recovered, and the submerged combustion can be smoothly recovered.

Example 3

The same porous end fitting structure as that of example 2 was employed except that, as shown in fig. 8, a mixing chamber 15 was provided after the first fluid and the second fluid flowed out of the first outlet port and the second outlet port, respectively, and the first fluid and the second fluid were premixed in the mixing chamber 15 and then introduced into the porous end fitting. The space defined by the mixing chamber is generally cylindrical, and the design of the mixing chamber can be performed by those skilled in the art according to important parameters such as the flow condition, residence time, injection speed and the like of the natural gas and the oxygen, and the shape of the mixing chamber is set to ensure that the natural gas and the oxygen flow and mix regularly and ensure the speed of injection into the porous terminal part. The mixing effect and the heat transfer efficiency of submerged combustion are further enhanced by increasing the contact area of oxygen and natural gas, forming a swirling motion and the like.

It will be appreciated that there are many more possible combinations between the various embodiments described above that may be used for a particular application. The invention is therefore not limited to the embodiments described but may be varied within the full scope of the appended claims.

The terms "first" and "second" as used herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another, unless otherwise specified. Similarly, the appearances of the phrases "a" or "an" in various places herein are not necessarily all referring to the same quantity, but rather to the same quantity, and are intended to cover all technical features not previously described. Similarly, modifiers similar to "about", "approximately" or "approximately" that occur before a numerical term herein typically include the same number, and their specific meaning should be read in conjunction with the context. Similarly, unless a specific number of a claim recitation is intended to cover both the singular and the plural, and embodiments may include a single feature or a plurality of features.

The embodiments described in the specification are only preferred embodiments of the present invention, and the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the present invention. Those skilled in the art can obtain technical solutions through logical analysis, reasoning or limited experiments according to the concepts of the present invention, and all such technical solutions are within the scope of the present invention.

Claims

1. A submerged combustion burner comprising a first fluid conduit, a second fluid conduit and a porous termination member, wherein,

the porous inlet end is directly connected with a first outlet end and a second outlet end respectively, and the M first fluid outlets and the N second fluid outlets respectively supply a first fluid or a second fluid to a molten environment outside the submerged burner, so that the first fluid and the second fluid are mixed and combusted in the molten environment;

wherein the equivalent diameter of the first pore channel and/or the second pore channel ranges from 0.8mm to 6mm, and the equivalent diameter, the shape and the distribution of the first pore channel and/or the second pore channel are configured to ensure that the infiltration depth of the melt in the melting environment into the porous terminal part within the operating temperature range of the melting environment is less than a preset value H, and the infiltration depth of the melt is positioned in the first pore channel and/or the second pore channel;

wherein the porous terminal member has a recessed end in the shape of an inverted cone; the preset value H of the infiltration depth ranges from 0mm to 15 mm;

wherein the submerged combustion burner further comprises a standby gas passage for introducing a standby gas into the first fluid conduit.

2. The submerged burner of claim 1, wherein the first fluid outlet and/or the second fluid outlet is formed to extend circumferentially from the center of the recessed end.

3. The submerged burner as recited in claim 1, characterized in that the preset value H of the penetration depth ranges from 5mm to 10 mm.

4. The submerged burner of claim 1, wherein the depth of the first port and/or the second port is equal to or greater than 25 mm.

5. The submerged burner of claim 1, wherein the equivalent diameters of the first and second orifices range from 1mm to 5mm, respectively.

6. The submerged burner of claim 5, wherein the equivalent diameters of the first and second orifices are in the range of 1.5mm to 4mm, respectively.

7. The submerged burner of claim 5, wherein the equivalent diameters of the first and second ports each range from 2mm to 3.5 mm.

8. The submerged burner of claim 1, wherein the equivalent diameter of one of the M first ports is different from the other, and/or the equivalent diameter of one of the N second ports is different from the other.

9. The submerged burner of claim 1, wherein the cross-sectional shapes of the first and second fluid outlets are: triangular, circular, oval, quadrilateral, quadralobe-shaped holes or sinusoidal.

10. The submerged burner of claim 1, characterized in that the first cells form an angle of 0 ° to 45 ° with respect to the direction of the central axis of the porous end part and/or the second cells form an angle of 0 ° to 45 ° with respect to the direction of the central axis of the porous end part.

11. The submerged burner of claim 1, wherein the first port and the second port each have a hole pitch greater than or equal to 2 times and less than or equal to 10 times the port diameter.

12. A submerged burner as claimed in claim 1, characterised in that the material of the porous termination member is selected from any one or a combination of two or more of zirconia, alumina, silica, metal carbides, borides, nitrides, suicides and electrofused silicon.

13. The submerged burner of claim 12, characterized in that the nitride is chosen from titanium nitride and/or zirconium nitride.

14. The submerged burner of claim 1, wherein N = M, and N and M are each positive integers greater than or equal to 1.

15. The submerged burner of claim 1, wherein one of the first and second fluids is an oxidant stream and the other is a fuel stream, respectively.

16. The submerged burner of claim 1, wherein the backup gas comprises nitrogen.

17. A melter system comprising:

a melting chamber containing a melt; a feed end and a discharge end for feeding raw materials into the melting chamber; and one or more submerged burners as claimed in any one of claims 1 to 16 defined in the melting chamber for injecting a flame into the melt.

18. A self-cooling submerged burner for a glass kiln, comprising: a first fluid conduit having an inlet end and an outlet end for passage of a first fluid; a second fluid conduit within the first fluid conduit having an inlet end and an outlet end for passage of a second fluid; one of the first and second fluids is an oxidant stream and the other is correspondingly a fuel stream; a porous end fitting having an inlet end connected to an outlet end of the first fluid conduit and an outlet end of the second fluid conduit, respectively, the first and second fluids not contacting before exiting the outlet end of the porous end fitting; the porous terminal part is provided with a plurality of pore channels penetrating through the inlet end and the outlet end of the porous terminal part, and the diameters of the pore channels are 0.3 mm-10 mm; wherein the size, shape and distribution of the channels are configured to cause the infiltration depth of the glass melt into the porous terminal part within the operating temperature range of the glass furnace to be less than a preset value H, and the infiltration depth of the melt is positioned in the first channel and/or the second channel; wherein the porous terminal part has a concave end in an inverted cone shape; the preset value H of the infiltration depth ranges from 0mm to 15 mm; the submerged combustion burner also has a backup gas circuit operable to introduce a backup gas into the first fluid conduit.

19. A self-cooling submerged burner as recited in claim 18, wherein there is a spacing member between all of the ports through which the first fluid flows and all of the ports through which the second fluid flows.

20. A glass furnace comprising a furnace wall defining a combustion chamber, at least one submerged combustion port, a feed port, a discharge port, and the self-cooling submerged burner of claim 18 or 19 disposed adjacent an edge of the at least one combustion port.