KR101546640B1 - Waveguide Assembly for Imparting Acoustic Energy to a Glass Melt and Method for Imparting Acoustic Energy to the Glass Melt - Google Patents

Abstract

The waveguide assembly 10 provides ultrasonic energy to the glass melt 12 in a size sufficient to create a sonic flow in the melt to mix the molten glass. The glass melt 12 will flow, for example, through the refractory metal container 14. The waveguide assembly 10 includes a waveguide 18 that is acoustically coupled to the waveguide 18 at the other end 20 and at the transducer 16 at one end 22. The waveguide 18 is physically coupled to the vessel 14 via threaded fittings 32, 34 attached to the outer surface of the vessel 14.

Description

TECHNICAL FIELD [0001] The present invention relates to a waveguide assembly for providing acoustic energy to a glass melt, and a waveguide assembly and method for providing acoustic energy to a glass melt.

The present invention relates to molten glass mixing, and more particularly to a waveguide assembly for providing acoustic energy sufficient to increase uniformity in a gals melt.

Current manufacturing techniques are capable of forming glass sheets with the functionality of a circuit board as well as high optical quality. One example in which glass sheets are used is a liquid crystal display (LCD). When used as an LCD substrate, the glass exhibits properties dependent on the glass melt forming the glass sheet.

Generally, the glass used in the LCD is an alkali-free alumino-borosilicate chemical composition. The glass sheet or panel used in the LCD is formed by controlled cooling of the liquid glass referred to as glass melt. However, such glass melts often contain inhomogeneities that can result in glass sheets that are unsatisfactory for the intended purpose. Examples of such heterogeneities include gas or solid inclusions, small sizes outside the density, and chemical compositions in the glass melt. Finally, phenomena are generally referred to as cords. Irregular distribution of the cord can reduce useful glass sheets. For example, in a liquid crystal display, a code may cause an anomaly that is not visually appealing in a display. In particular, the code is a specific region having different refractive indices. Certain regions of different refractive index can be glasses that are not suitable for a number of precise functions.

Prior to this, mechanical stirrers have been used to directly provide mechanical agitation of the glass melt. However, high glass melt temperatures and the aggressive nature of the glass composition can make it difficult to directly perform mechanical agitation. The stirring elements are made of expensive refractory metal components such as platinum or platinum-rhodium alloy to withstand the high temperature environment. Moreover, a high shear stress can corrode both the glass containing the agitating member and the vessel, and can lead to the release of unwanted particulates into the molten glass.

Generally, ultrasonic energy, vibration energy, has been used in various fields. Ultrasonic energy is most commonly used to shake fluids in cleaning processes such as ultrasonic cleaning of gemstones. In addition, in the industry, ultrasonic energy has often been used to remove gases from liquids. It facilitates the removal of gaseous inclusions (bubbles) from the liquid.

In U.S. Pat. No. 4,316,734, acoustic energy incorporates small seeds (bubbles) into larger bubbles so that they can be flashed at a rapid rate without changing the viscosity of the melt during the glass manufacturing process. As a result, the viscosity of the glass melt can be increased so that it does not over-affect at least the larger bubbles in the melt due to temperature reduction. Decreasing the melt temperature can lead to significant energy storage.

U.S. Pat. No. 4,316,734 discloses a method for determining the frequency and energy responsive to acoustic impedance and the glass viscosity at the interface between the acoustic energy source and the glass to provide a mode of operation in which a significant proportion of bubbles move up in the glass, intensity is selected.

Also, U.S. Patent No. 2,635,388 discloses a method for removing a gas mixture from a molten glass. U.S. Patent No. 2,635,388 discloses the use of a heated element that is dipped in molten glass to ultrasonically vibrate. The heating element helps to collect the bubbles and when combined with agitation generated by a vibrating element that facilitates their removal from the glass, generates a localized high temperature at low viscous areas upon melting. The convection currents generated by the heating eventually occur throughout the glass passing through the local high temperature region.

Although these and other methods have shown some efficacy in removing air bubbles from glass as an application of acoustic energy, they show the effective mixing of molten glass (for example, to eliminate chemical non-uniformity) to homogenize the glass I did not give it. Moreover, the method disclosed in U.S. Patent No. 2,635,388 requires the insertion of a heated oscillating member in a glass melt. Chemically high temperatures, which are too much of the environment of glass melt, can cause flow disruption and decomposition of heated vibrating members over time, and can result in periodic exchange of contamination or absence of glass melt, depending on the material of the member Can be minimized. Thus, the remaining glass mixing method can effectively remove the cord from the glass melt without the drawbacks of inserting additional members into the melt.

The present invention describes how a waveguide assembly can be used to introduce ultrasonic waves at a given frequency and power level into either a continuous wave form in a glass melt or in the form of a long (multi-cycle) explosion. First, excitation signal waveforms change to a sine wave shape, but waveforms in the sound field will be different because of the significant nonlinearity in the melt. For purposes of performance and theoretical discussion, a multi-cycle explosion will be treated as an equally successive wave signal. Thus, sound fields in an excitation apparatus can basically be treated as monochromatic (single frequency).

An excitation device for converting electrical input energy from a radio frequency power source into acoustic output energy in the melt is made up of a series of daisy-chained components.

1. Transducer (s) suitably configured with one or more active (piezoelectric) components complemented by front and rear dimensions

2. Optical matching, a solid material containing a discontinuous or progressive diameter step,

3. A rod waveguide that is a cylindrical rod of usually constant diameter.

To effectively transmit through such a chain, each of the components is designed to resonate at a target frequency. The losses in the resonator can be neglected and their magnitudes are exactly equal to the number of half waves when terminated by components with infinite impedance matching (infinitely rigid or infinitely flexible).

The waveguide of the given mode type is equal to the sound velocity in the material and is the same as the waveform of the problem divided by frequency. Thus, at a particular frequency, wavelengths are different among the various components of a chain made up of a wide variety of materials. Moreover, the waveforms which depend to some extent on the cross-section and on the cross-sectional variation of the components affect the wavelength to a lesser extent.

To make an effective excitation chain, all components can be tuned to the same frequency. Since the deviations from simple assumptions vary from component to component, these differences require different adjustments for each component. For example, the diameter grades in a matched link are not infinitely steep. This is because it uses a limited filtering radius to limit the occurrence of stress in the link during operation. This filtering has some effect on the optimal length.

The waveguide assembly may be driven at a suitable resonant frequency, e.g., 20 kHz to 40 kHz, to provide sufficient acoustic power to the glass melt to enhance mixing within the glass melt. Preferably, the acoustic power coupled to the glass melt is greater than 5W, preferably at least 30W, more preferably at least 40W, even more preferably at least 50W. According to an embodiment of the present invention, sufficient acoustic power can be provided to the glass mix to effect a non-linear acoustic effect.

In one embodiment, a method of mixing a glass melt comprises: generating an acoustic wave; And coupling the sound waves to the glass melt through a waveguide, wherein the sound waves provide sufficient acoustic power to the glass melt to create acoustic streaming in the glass melt.

Sufficient acoustic energy, such as ultrasonic energy, can be provided to the glass melt to increase the uniformity in the glass melt while acoustically connecting the waveguide to the glass melt and making standing waves along the waveguide's length.

In another embodiment, an apparatus for providing sonic energy to a glass melt in a vessel includes a transducer for generating a sound wave, a waveguide acoustically coupled to the transducer, and a glass melt, wherein the waveguide is a standing wave to create a standing wave, and to create an acoustic flow in the glass melt.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this invention. The figures are not necessarily to scale, and the sizes of the various components are distorted for clarity. The drawings illustrate one or more embodiments of the invention and, together with the description, serve to explain the principles and operation of the invention.

1 is a cross-sectional view of a device for mixing molten glass in a cylindrical container according to a preferred embodiment of the present invention.
2 is a cross-sectional view of another embodiment of a glass mixing apparatus in which a waveguide includes an impedance matching section according to an embodiment of the present invention.
Figures 3 and 4 are cross-sectional views of a method of acoustically connecting a waveguide to a vessel using a threaded socket and a threaded stub.
5 is a cross-sectional view of another embodiment of an apparatus in which two waveguides are acoustically connected to a vessel in accordance with an embodiment of the present invention.
Fig. 6 is a conceptual diagram of a preferable process for producing a molten glass using the embodiment of the present invention.

Sound is vibration that moves or spreads through a medium such as a liquid or gas. The source of this vibration is the repetitive perturbation of the medium. For example, a bell vibrates when hit. The side of the species moves against the surrounding air, forming a high pressure area in the air as the side moves out and a low pressure area in the air as the side moves in. The high and low pressure regions are known as compressed and lean regions, respectively, and they are transmitted through the medium as waves that affect adjacent air molecules. Air molecules move back and forth in response to alternating high and low pressures, and behave alternately according to adjacent molecules. Hence, the high and low pressure regions are transmitted through the medium as a wave with a set amplitude and wavelength. When it is transmitted, the propagating waves diverge from space and lose energy by absorption. These two effects produce a pressure that reduces the travel distance. Also, propagating waves can affect other waves, either structurally or destructively. For example, a wave can be overlapped with the reflection of a wave (for example, from the surface of an object), so that the two waves are strengthened with each other to generate a standing wave. This occurs when two waves synchronize with each other. Standing waves have a setpoint and an antinode set to respond to the region of minimum pressure and maximum pressure, respectively. Standing waves are generated in an environment in which a wavelength (frequency) of a wave propagating in an appropriate number of half wavelengths is adjusted to be reflected, so that the reflected waves are structurally overlapped.

Normally standing waves can be quite intense. However, extremely intense sounds lead to nonlinear responses in the medium through where they propagate. These nonlinear responses can include a net flow process of the medium, which includes shock wave, acoustic saturation (the medium can not absorb additional acoustic energy) and acoustic flow, or the sound wave is a propagation result . The vibrating molecules described above are net changing at all locations as well as "spatial movement" The intermediate position of the molecules in the acoustic flow changes.

Acoustic flow has been used to control the properties of fluids such as, for example, moving relatively low temperature fluids, moving bubbles, and fluids discharging into small droplets. In addition, acoustic flow has been used for local mixing (e.g., microfluidic mixing) of very small fluids. A much more difficult task is to cause acoustic flow to high viscosity, high temperature bulk liquids, such as molten glass, in many glass manufacturing processes to effectively and economically mix or homogenize the glass.

The term "glass melt" includes various glass constructions of the respective softening points described above. Generally, the glass melt is approximately 1200 ° C to 1700 ° C. The term "glass " includes materials composed of any liquid-like (non-transparent) molecular structure. The manufacturing process of the glass requires a raw material which is heated to a temperature sufficient to produce a fully dissolved melt and which solidifies without crystallization upon cooling. The glass and thus the glass melt are not limited to soda lime glass, but may be lead glass, borosilicate glass, aluminosilicate glass, 96% quartz glass (silica glass, molten quartz glass, and aluminoborosilicate silicate. The term "sound wave" means to include mechanical vibrations transmitted through the medium. In one embodiment, the sound waves are generally in the ultrasonic range with a target frequency of 20 kHz to 40 kHz.

The present invention relates to a waveguide assembly 10 that mixes a glass melt by providing sonic acoustic energy to a glass melt 12 contained in a vessel 14 as shown in Figure 1, .

The container 14 can be in any one of a variety of forms. In one embodiment, the vessel 14 establishes fluid passages for the selected molten glass along with the waveguide assembly 10 to permit mixing within a given ratio of the fluid path cross-section. Therefore, the vessel 14 can allow the flow of molten glass and glass melt flowing from the upstream position to the downstream position. For example, the container 14 may be a pipe through which the molten glass circulates. In one embodiment, the container 14 includes an open top that allows the waveguide assembly 10 to access and contact the glass melt. The vessel 14 may include a port or hole below a level of the glass melt where a portion of the waveguide assembly 10 is disposed to be coupled to the waveguide assembly 10 and the glass melt . In another construction, the waveguide assembly can be acoustically coupled to the vessel at the outer surface of the vessel to avoid the disadvantages of the prior art mixing methods described above. The acoustic coupling is that the first member is coupled to the second member in the same way that the sound waves can be transmitted from the first member to the second member with minimal amplitude loss.

The vessel 14 is comprised of a refractory metal such as platinum or a platinum-rhodium alloy (e.g., 80% platinum and 20% rhodium alloy). The container 14 includes an inlet opening and an outlet opening, and the molten glass flows through the container in a continuous or semi-continuous glass manufacturing process. However, it can be seen that the methods of the present invention operate on molten glass that does not flow.

The waveguide assembly 10 is configured to include a transducer 16 that performs a transformation to effectively convert radio frequency power to acoustic power and a waveguide 18 for delivering acoustic power to the glass melt 12 do. To improve power transfer, the waveguide assembly 10 is configured to match the acoustic impedance within the assembly and resonate at a target frequency. Therefore, the assembly can be neglected in resonance loss and the waveguide assembly is defined by the component with an infinite impedance ratio (infinitely straight or infinitely flexible), and the vertical dimension of the waveguide assembly will exactly match the number of half waves.

In one embodiment, the first end 20 of the waveguide 18 is acoustically coupled to the glass melt 12 through the vessel 14 and the second end 22 of the waveguide 18 is coupled to the transducer 16). The waveguide 18 (and the waveguide assembly 10) may be used to assist in the operation of the first hot end 20 and ambient temperature, or at least the transducer, generally above 1200 ° C, i.e. 1200 ° C to 1700 ° C. Lt; RTI ID = 0.0 > 22 < / RTI > Conventional ultrasonic transducers will end up to nearly 50 ° C. At higher temperatures, the transducers will suffer permanent damage due to internal debonding or depolarization caused by thermal expansion. In one embodiment, the temperature of the transducer 16 is kept below 100 ° C, preferably below 50 ° C.

The transducer 16 converts the RF power into oscillatory motion. The transducer may be any of a variety of commercially available transducers, such as a Langevin or Tonpilz type ultrasonic transducer. The transducer is driven by a signal generator 24 and a high-frequency power amplifier 26 as is known. The signal generator 24 is alternately controlled by a controller such as a controller of a computer board.

The excitation signal voltage and frequency input to the transducer are controlled by the controller 28 to enable the transducer 16 to operate at an optimal working point for efficient ultrasound generation. The waveguide assembly 10 is operated at a resonant frequency. In particular, the transducer type transducer is known to have resonant characteristics that depend on the narrow resonant frequency bandwidth and the medium. Since the waveguide assembly, in particular the waveguide, is exposed to a temperature range, the resonant frequency is temperature dependent.

To match the acoustic impedance between the transducer 16 and the waveguide 18, the waveguide 18 includes a portion of the matching link 30. In one embodiment, the mating link 30 is designed to have a half-wavelength length of the target frequency within the mating link as shown in Fig. Therefore, the length of an interchangeable material, such as steel, is chosen as the wavelength of almost half the target signal in steel. Although steel is used as the matching link 30, other materials with acceptable acoustic characteristics and losses may also be used, and the optimal size of the matching link may be selected to match the acoustical input impedance of the waveguide to the acoustic impedance of the transducer. do.

The matching link 30 is configured to minimize signal reflections at the interface between the transducer and the matching link and at the interface between the matching link and the remainder of the waveguide. Therefore, the amount of power reflected at each interface is minimized and the total power delivered to the glass melt 12 is maximized.

As described above, transducer 16 is acoustically coupled to waveguide 18 at waveguide end 22. The remaining end 20 of the waveguide 18 is dipped in a glass melt or is acoustically coupled to the outer surface of the vessel 14 so that preferably acoustic power is delivered to the glass melt through the vessel 14.

3 and 4 are diagrams illustrating various methods of acoustically connecting waveguide 16 to vessel 14 in an embodiment of the present invention. 3 is a view showing an inner spiral socket (fitting) 32 attached to the outer surface of the container 14. As shown in Fig. Thus, the end 20 of the waveguide 18 includes an external thread that the waveguide 18 can wind into the socket 32. 4, the waveguide 18 includes an end portion 20, which is sized to engage with a threaded stud (fitting) 34 attached to the outer surface of the container 14, Spiral grooves. The studs 34 are preferably bonded to the container 14. Preferably the end surface 23 of the stud 34 is perpendicular to the transverse axis of the stud 34 (the stud 34 has a flat end surface) And contacts the inner grooves of the stud 34 across the end surface.

The waveguide 18 is selected to resonate at a target frequency (supporting a standing wave). Therefore, the waveguide 18 has a length equal to an integral multiple of a half-wavelength of the target frequency in the waveguide. In various embodiments, the waveguide 18 is partially immersed in the glass melt 12 such that the undoped length of the waveguide operates as a thermal buffer between the transducer 16 and the glass melt 12 . In the non-soaked embodiment, the entire length of the waveguide 18 operates as a thermal buffer.

The waveguide 18 is made of a material that is sufficient to withstand the high temperatures used in the glass manufacturing process (which may exceed 1600 占 폚). This is true even if the waveguide 18 contacts the molten glass or contacts the vessel 14. Satisfactory materials are known to include dense alumina, ceramics or refractory metal alloys that maintain high modulus at high temperatures, such as alumina, zirconia and platinum-rhodium alloys.

Although the waveguide 18 is generally cylindrical or a stepped conical shape, the waveguide 18 may have a longitudinal, block, or rolled shape (grooved or not grooved). The waveguide 18 may be a hollow solid having a diameter similar to a solid rod or tube or solid rod.

In one embodiment, the cooling stream 36 is directed over a portion of the waveguide 18 (or where the matching link 30 is used) to provide an appropriate operating temperature to the transducer 16. The cooling flow can be air at ambient (or indoor) temperature among the instantly obtainable flow rate. However, it can be seen that the cooling flow 36 may be a cooled fluid. Furthermore, it can be seen that the shorter waveguide includes a larger required cooling and a cooler cooling flow at higher flow rates. It can be seen that the cooling flow of ambient air is suitable for waveguides of wavelength length. Generally, the cooling flow is directed beyond the waveguide (or matching link) adjacent to the transducer. The cooling flow is in the steady state because it allows the waveguide to reach equilibrium.

Because waveguide 18 includes a hot end and a cold end, there is a thermal change along the length of the waveguide so that the velocity of the sound wave propagating through waveguide 18 is changed. The frequency of the sound waves generated by the transducer 16 is adjusted to maintain resonance within the waveguide assembly 10 to provide sufficient acoustic power to the glass melt 12. [ In addition, the combined temperature differences vary in ultrasonic losses and ultrasound properties of the melt. Therefore, even if the waveguide maintains resonance by frequency control, the impedance of the electrical input of the transducer at resonance will vary. The temperature variation along the waveguide assembly 10 between the glass melt 12 and the room temperature transducer 16 leads first to a change in sound wave velocity along the length of the waveguide assembly and secondly to thermal expansion, The density is changed. Both effects will all respond to changes in the acoustic impedance set by the acoustic pressure distributed by the volume velocity along the length of the waveguide assembly. Thus, the temperature decrease change in acoustic impedance along the length of the waveguide assembly is important in selecting components for the device, such as waveguide material, length and cross section.

The optimal length of the waveguide 18 depends on the temperature of the waveguide during material selection and operation of the waveguide. The wavelength length of the single wavelength for the target sonic frequency is set so that the transducer 16 allows a sufficient temperature variation along the length of the waveguide to operate at a temperature less than 100 DEG C and is adjusted over the signal frequency to operate at the resonant frequency It will be appreciated that in many embodiments the length of the waveguide 18 is sufficient, such as allowing the waveguide assembly 10.

When the waveguide 18 is acoustically coupled to the glass melt 12, the waveguide delivers acoustic power in the form of ultrasonic vibrations through the vessel 14 to the glass melt. As the glass melt is supplied with sufficient power, the movement of the glass melt mixed sufficiently to increase the uniformity of the glass melt can be induced. The cording can be reduced and evenly distributed throughout the glass melt. In various embodiments, the acoustic power coupled to the glass melt makes cavitation with a melt that can lead to a high flow rate in the melt. The cavitation can promote fining (removal of gas inclusions) of the glass by creating a vacuum bubble position where the dissolved gases can be incorporated into one and can rise to the surface of the glass melt.

In certain embodiments, one or more waveguides are used to enhance the mixing of the molten glass. 5 is an illustration of an embodiment in which two waveguides are physically coupled to the vessel 14. Preferably, the length axes of the two waveguides are at right angles. It can be seen that more than one waveguide is used. 6 is a schematic diagram illustrating a preferred glass manufacturing system 42 in accordance with an embodiment of the present invention using a fusion process to produce glass sheets. The dissolution process is described in U.S. Patent No. 3,338,696. A preferred molten glass manufacturing system 42 includes a melting furnace 44 (melter) in which raw feed materials are inserted such as arrows 46 to form molten glass 12, . The glass manufacturing system 42 generally comprises a refractory metal such as molybdenum, palladium, rhenium, tantalum, titanium, tungsten, or their alloys Platinum or platinum-containing metals, such as platinum-rhodium, platinum-iridium, and combinations thereof. The platinum-containing components may include a purifying vessel 50 (e.g., a finer tube 50), a pipe 52 connecting the microtubule and the dissolution apparatus, a mixing vessel 54 (e.g., A stir chamber 54), a pipe 56 connecting the stirring chamber and the micro tube, a delivery vessel 58 (bowl 58), a pipe connecting the main stem and the stirring chamber (60) and a downcomer (62). The molten glass is provided to an inlet 64 coupled to a forming vessel 66 (e.g., a fusion pipe 66). The molten glass provided in the molding container 66 through the inlet 64 overflows from the molding container 66 and is separated into two separate glass flows flowing under the outer surface of the molding container 66 which is gathered. The two separate glass flows recombine at a line where the gathered molding surfaces meet to form a single glass sheet 68. The molding container 66 is formed of a ceramic or glass-ceramic heat-resistant material.

The bonded glass sheet having the initial outer surface is suitable for manufacturing a liquid crystal display device because the outer surface of the separated glass flow downwardly facing the molding surface of the gathered molding container 66 does not contact the molding surface.

In accordance with an embodiment of the present invention, the apparatus 10 will be used as a platinum-containing portion of the glass manufacturing system 42. For example, the one or more devices 10 are acoustically connected to a piping 56 or agitating chamber 54 connecting a stirrer and a microtubule to mix (homogenize) the molten glass. In a conventional stirring chamber, the stirrer 70 is rotated in the molten glass to homogenize the glass. The apparatus 10 is used for replenishing the stirrer 70 or instead of the stirrer 70 to simultaneously provide ultrasonic energy to the glass melt while the stirrer is rotating.

Example  One

The aluminoborosilicate glass pieces are again dissolved at the temperature of the platinum-rhodium crucible placed in a furnace varying between 1350 ° C and 1535 ° C. The waveguide comprises an alumina portion and the steel impedance matching is acoustically converted to a glass melt by a Tone-Filitz type ultrasonic transducer operating between about 20 kHz and 25 kHz so that the length of the alumina part is saturated with the glass melt Used to connect. The alumina part has a diameter of 22 mm and a length of 43.2 cm. Significant resonance conditions occur at an operating frequency between 21.1 kHz and 21.4 kHz, which represents the transducer's electrical impedance at its minimum value (the frequency is adjusted to the above range to maintain resonance due to the temperature dependence of the waveguide). The maximum input power of 44 W is obtained at a furnace temperature of 1350 ° C. Cobalt oxide is added to the glass melt in an amount of approximately 200 ppm to provide visual evidence of acoustical flow. The glass is cooled and removed from the crucible. A visual review of the cooled glass shows the acoustic flow induced by mixing the cobalt oxide "hue" with the glass.

Example  2

Aluminoborosilicate glass is melted in a platinum-rhodium crucible (vessel) placed in a furnace between 1350 ° C and 1400 ° C, and then maintained at a temperature of 1450 ° C. The waveguide includes an alumina portion and the steel impedance matching portion is used to acoustically connect a Tone-Fitz-type ultrasonic transducer operating between about 20 kHz and 25 kHz to the glass melt. The alumina part has a diameter of 22 mm and a length of 43.2 cm. The alumina portion of the waveguide is physically coupled to the crucible via a threaded stud welded to the outer surface of the crucible and internally joined to the threaded groove in the alumina portion of the waveguide. The impedance matching portion is coupled to the transducer via an attached, reinforced screw. Significant resonance conditions occur at an operating frequency between 22.5 kHz and 23 kHz, which represents the transducer's electrical impedance at its minimum value (the frequency is adjusted to the above range to maintain resonance due to the temperature dependence of the waveguide). The input power of the glass melt is 40W to 50W.

It will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit of the invention. Accordingly, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims (5)

Generating a sound wave; And
And coupling the sound waves to the glass melt (12) contained in the vessel through the waveguide (18)
Wherein the waveguide is coupled to an outer surface of the vessel and includes a matching link (30) to match acoustical impedance between the waveguide and the transducer (16);
The frequency of the sound wave is adjusted to make a standing wave in the waveguide; And
Wherein the sound waves provide sufficient acoustical power to the glass melt to produce an acoustic flow in the glass melt. The method according to claim 1,
Characterized in that the glass melt is contained in a refractory metal container (14). 3. The method of claim 2,
Wherein the waveguide is physically coupled to the screw fittings (32, 34) at the surface of the vessel. The method according to claim 1,
Wherein the step of bonding acoustic waves to the glass melt comprises contacting the glass melt with the waveguide. An apparatus for providing acoustic energy to a glass melt in a vessel (14)
A converter 16 for generating sound waves; And
And a waveguide (18) sonically coupled to the transducer and the glass melt,
The waveguide 18 is associated with the outer surface of the vessel and the frequency of the sound waves is adjustable to produce a standing wave within the waveguide at the frequency of the sound waves and to produce a sound wave flow in the glass melt 12; And
Characterized in that the waveguide (18) comprises a portion of the matching link (30) to match the acoustic impedance between the transducer (16) and the waveguide.

Images