JP6639522B2 - Apparatus and method for tempering molten glass - Google Patents

Description

priority

  This application claims the benefit of priority of US Provisional Patent Application No. 62 / 157,576, filed May 6, 2015, under 35 USC 119, which is incorporated by reference. The content is authoritative and is incorporated by reference herein in its entirety.

  The present disclosure is directed to an apparatus for processing molten glass, and more particularly, to an apparatus for mixing molten glass.

  Production of glass on a commercial scale is typically carried out in a refractory ceramic melting furnace, in which the raw materials (batch) are added to the melting furnace and heated to a temperature at which the batch undergoes a chemical reaction. Produce glass. Several methods of heating the batch can be used, including gas-fired burners, electric current, or both. In a so-called hybrid process, a gas flame from one or more gas-fired burners first heats the batch. As the temperature of the batch increases and the molten glass is formed, the electrical resistivity of the material decreases, thereby allowing current to be introduced into the molten glass through electrodes located on the side walls and / or floor of the melting furnace. . This current heats the molten glass from the inside, and the gas burner heats the molten glass from above. In some embodiments, submerged combustion can be employed.

  The downstream processing, such as growth and homogenization, of the molten glass is carried out in a specific part of the furnace structure or in another vessel located downstream of the melting furnace and connected to the melting furnace by a conduit. it can. The molten glass may be heated to maintain an appropriate temperature of the molten glass as it is conveyed. In some processes, such as the fining process, heating the molten glass to a temperature above the furnace temperature in the fining vessel can promote more complete removal of air bubbles from the molten glass. Downstream of the melting furnace, in other parts of the manufacturing equipment, the molten glass can be cooled while flowing through one or more conduits to a viscosity suitable for forming the molten glass. However, this cooling can be limited by a controlled addition of thermal energy to prevent the cooling rate from becoming too fast.

  This melting process can produce a stream of molten glass to a downstream process, which, without further processing, can be heterogeneous for at least one or more of the following reasons: 1) Granules Incomplete melting of raw materials; 2) decomposition of refractories constituting the melting vessel; 3) volatilization from the free surface of the molten glass; 4) mixing of several glass phases of different density; and 5) different compositions. Transition between glasses. As a result, chemical and thermal inhomogeneities can be present in the molten glass, which can result in visible refractive index fluctuations when the molten glass is formed into a finished article and cooled. is there. If the finished article is a drawn article, such as a glass ribbon or sheet, the areas of differing index of refraction will stretch and elongate, as long and thin streaks, or more commonly as striae. May be visible. In some instances, striae may further manifest as slight variations in the thickness of the glass article. Thus, the glass article may include surface wrinkles having a variable spatial period of about 1 to 10 millimeters (mm) and a depth typically greater than 10 nanometers (nm).

  For the manufacture of optical quality glass, such as glass suitable for the manufacture of display panels (eg, liquid crystal display panels) used in devices such as televisions, computer monitors, tablets, smartphones, etc., removal of these non-uniform areas is of paramount importance. It is. High striae are undesirable. This is because it affects the quality of the display, both visually and functionally. Visually, striae may appear as multiple dark lines in the draw direction as a result of the lensing effect created by the curvature of the corrugated surface. Functionally, large striae can create variations in the cell gap of a liquid crystal display (LCD) device, which can affect the operation of the liquid crystal. Therefore, efforts have been made to mix molten glass with the viscosity of the glass being low enough to effectively remove striae by mixing. The mixing can be passive, in which a plurality of stationary vanes positioned in the flow of molten glass repeatedly changes the direction of flow of the molten glass. Alternatively, the molten glass may be actively mixed by flowing the molten glass through a mixing container such as a stirring container provided with a moving member such as a rotary stirrer.

  Stricter commercial striae standards, increased striae due to increased glass flow rates, or the introduction of new glass compositions that are difficult to melt, have improved the mixing performance of mixing vessels, and especially stirring vessels. The need for improvement is increasing.

  For a given stirring vessel configuration, the mixing intensity can be increased by increasing the revolutions per minute (RPM) of the stirrer positioned within the stirring vessel. However, RPM has hardware limitations, and as the size of the stirrer increases, the RPM decreases. That is, as the diameter of the stirring blade increases, the speed at which the stirrer blade can be effectively rotated within the stirring vessel decreases. In addition, high RPM can also produce deleterious side effects, including increased metal (eg, platinum or platinum alloy) inclusions created by corrosion of the mixing vessel, and reduced agitator life.

  The RPM setting of the stirrer during operation is a trade-off between mixing the striae to the desired level and minimizing platinum or platinum alloy inclusions without sacrificing the life of the stirrer. is there. It would be desirable to find a way to achieve improved agitation effectiveness that would cleverly avoid this trade-off.

  In certain glass making processes, the raw materials (the mixture is typically referred to as a batch) are exposed to one or more high-temperature heat sources, where the raw materials chemically react to produce a molten material, hereafter referred to as molten glass. Then, this is formed into an article by a forming apparatus, and this is appropriately cooled to obtain a glass article. For those having no particular skill in the art, high-temperature processing to form molten glass is typically referred to as a melting process, and for the purposes of the following discussion, this designation may not be strictly accurate. That's enough. In any case, during the melting process, the resulting molten glass is far from homogeneous. Initially, the raw materials typically have a granular nature, so that very small areas of the molten glass may have a different chemical composition than adjacent small areas. Similarly, there may be temperature fluctuations, and one region of the molten glass may be at a different temperature than another. Such chemical and thermal inhomogeneities of the molten glass, if not reduced, include, but are not limited to, refractive index differences that are readily observable to those with only average visual acuity, such as finished glass. This can lead to variations in the properties of the article. During the downstream forming process, a process that employs some method of drawing (stretching) the molten glass will convert the heterogeneous small regions into long filaments (ie, striae) that are generally parallel to the drawing direction. May be extended. Such filaments are easily observable in the finished glass article. In instances where the glass article is a glass sheet, for example a glass sheet used in the manufacture of a display device (eg, a liquid crystal display device), these filaments will cause distraction to the viewer of the glass sheet. In addition, these filaments can cause thickness variations in the glass sheets, which can lead to differences in the gap between the parallel glass sheets that make up the LCD display panel, impairing the function of the display panel. obtain. Even in instances where the glass sheet can be further processed, such as by milling and / or polishing, the difference in refractive index remains. Accordingly, glass manufacturers employ various means for homogenizing the molten glass.

  In some processes, one or more heat sources, such as electrodes for establishing a current in the molten glass, are provided to maximize mixing by creating a desired convective current in the molten glass. Produces complete melting. Some processes may utilize a bubble generator configured to introduce a gas into the molten glass. Bubbles pass through the molten glass and rise to the free surface of the molten glass, while introducing a mechanical movement that assists in mixing the molten glass.

  In some processes, mixing in the melting furnace can be enhanced by further downstream mixing. For example, such additional mixing may be performed by flowing the molten glass through a container specifically configured to agitate the molten glass. In one exemplary stirring operation, the stirrer can be rotatably mounted in a vessel downstream of the melting furnace, and as the molten glass passes through the vessel, the agitator rotates within the vessel to provide mechanical mixing of the molten glass. Produces. Typically, the stirrer comprises a shaft and one or more stirring blades, the one or more stirring blades being disposed on the shaft and extending outwardly from the shaft, The rotation of the shaft "cuts" the filament, dispersing it throughout the volume of the molten glass. In some embodiments, the agitator may be of the screw type, with a shaft around which one or more blades are spirally or otherwise wound. In other embodiments, the agitator may be of the paddle type, comprising one or more paddles arranged in a predetermined pattern along the shaft. Other configurations are possible, including a paddle having an opening in the face of the paddle, and a skeletal member with a configuration of a plurality of connected bar members, e.g., reminiscent of a mixing blade for a cooking mixer. .

  One aspect that these aforementioned mixing vessels may have in common is that one or more mixing blades need to be submerged below the surface of the molten glass. If one or more mixing blades are exposed at the free surface of the molten glass, lapping can occur that traps gases (eg, air) in the molten glass. Entrapped air, even small air bubbles, can form additional observable defects in the finished article and is therefore undesirable. Thus, one or more mixing blades are typically positioned well below the free surface of the molten glass. However, analysis of the flow may indicate that positioning one or more mixing blades below the free surface of the molten glass may result in the molten glass above the mixing blade exhibiting a stationary area. I know it. That is, the stagnant areas of the molten glass are substantially free of severe mixing under steady-state conditions, and the molten glass in these areas leaks out of the stationary area in certain stirrer designs, such as the vessel wall and stirring blades. Bypass the mixing blade along the path between

  Accordingly, the present description describes an apparatus for tempering molten glass, the apparatus comprising: a container; a main stirrer positioned within the container and rotatable about a first axis of rotation; A main stirrer, wherein the main stirrer comprises a main stirrer shaft and a topmost main stirrer blade extending outwardly from the main stirrer shaft by a distance dm with respect to the first axis of rotation; And a first inlet agitator positioned within the container and rotatable about a second axis of rotation offset by a distance da less than the dm from the first axis of rotation.

  With respect to a horizontal plane extending through the vessel, the uppermost main stirring blade is positioned below the horizontal plane and the first inlet agitator does not extend below the horizontal plane.

  The device may further include a delivery conduit opened into the container and configured to deliver the molten glass to the container, the delivery conduit having a central longitudinal axis. Subsequently, with respect to a first vertical plane extending through the container perpendicular to the central longitudinal axis of the delivery conduit, the first axis of rotation is generally the first vertical plane. And wherein the first inlet agitator is positioned on the same side of the first vertical plane as the delivery conduit.

  Also, the apparatus may further comprise a second inlet stirrer, wherein the second inlet stirrer is positioned in the container and offset from the first axis of rotation by the distance da. It is rotatable about a third axis of rotation and is positioned on the same side of the first vertical plane as the delivery conduit. Thus, with respect to a second vertical plane perpendicular to the first vertical plane, the central longitudinal axis of the delivery conduit lies entirely in the second vertical plane and the second rotation The axis and the third axis of rotation are equidistant from the second vertical plane.

  The apparatus may further include a second inlet agitator positioned on the first vertical surface opposite the delivery conduit.

  The device may for example comprise a plurality of inlet agitators.

  In certain embodiments, the container is cylindrical and the first axis of rotation coincides with the central longitudinal axis of the container.

  In another aspect, an apparatus for tempering molten glass is disclosed, the apparatus comprising: a vessel; a main stirrer positioned within the vessel and rotatable about a first axis of rotation, wherein A main stirrer comprising: a main stirrer shaft; and a topmost main stirrer blade extending outwardly from the main stirrer shaft by a distance dm relative to the first axis of rotation; A first inlet agitator positioned within the vessel and rotatable about a second axis of rotation offset from the first axis of rotation. Thus, with respect to a horizontal plane extending through the vessel, the uppermost main stirring blade is positioned below the horizontal plane and the first inlet agitator does not extend below the horizontal plane.

  The first inlet stirrer may be positioned, for example, in an upstream volume of the vessel, and the uppermost stirring blade is positioned in a downstream volume of the vessel.

  The upstream volume and the downstream volume may be cylindrical volumes, and a central longitudinal axis of the upstream volume may coincide with a central longitudinal axis of the downstream volume.

  The device may for example comprise a plurality of inlet agitators. Each of the plurality of inflow-side agitators can be positioned in the container and can rotate about a rotation axis that is offset from the first rotation axis by a distance da less than the dm. It can be.

  The device may further comprise a delivery conduit opened into the container and configured to deliver the molten glass to the container, the delivery conduit comprising a central longitudinal axis, and the delivery conduit comprising: With respect to a first vertical plane extending through the container perpendicular to the central longitudinal axis of the conduit, the first axis of rotation is generally in the first vertical plane; The first inlet agitator may be positioned on the same side of the first vertical plane as the delivery conduit.

  The apparatus may further comprise a second inlet stirrer, wherein the second inlet stirrer is positioned in the container and has a third rotational axis offset from the first rotational axis. And is positioned on the same side of the first vertical plane as the delivery conduit and with respect to a second vertical plane perpendicular to the first vertical plane, The central longitudinal axis is generally in the second vertical plane, and the third axis of rotation is positioned on the opposite side of the second vertical plane to the second axis of rotation. Good. In some embodiments, the second axis of rotation and the third axis of rotation are equidistant from the second vertical plane.

  In still yet another aspect, a method for tempering molten glass is described, the method comprising: flowing molten glass from a delivery conduit into a container, wherein the container includes a flow of molten glass. Agitating the molten glass in the upstream volume with a first inlet agitator rotatable about a rotation axis; and a molten glass in the downstream volume. Is stirred with a main stirrer rotatable about a rotation axis parallel to the rotation axis of the first inflow-side stirrer, wherein the main stirrer comprises a top-most stirring blade, A step, wherein with respect to a horizontal plane extending through the vessel, the uppermost stirring blade is positioned below the horizontal plane and the first inlet agitator is generally above the horizontal plane. It is positioned.

  The uppermost stirring blade may have, for example, a length dm that is a maximum extension range of the uppermost stirring blade from the rotation shaft of the main stirrer, and the rotation shaft of the first inflow-side stirrer may be provided. And the offset between the main agitator and the rotation axis is less than the dm.

  The method may further include agitating the molten glass with a second inlet stirrer having a rotating shaft, wherein the second inlet stirrer is positioned generally above the horizontal plane. The offset between the rotation axis of the second inflow-side stirrer and the rotation axis of the main stirrer may be less than the dm.

  In some embodiments, with respect to a vertical plane perpendicular to a central longitudinal axis of the delivery conduit, the central longitudinal axis of the container lies entirely in the vertical plane and the first inlet side agitator. A vessel and the second inlet agitator are positioned between the vertical surface and the delivery conduit.

  In some embodiments, the direction of rotation of the first inflow stirrer may be the same as the direction of rotation of the second inflow stirrer.

  In some embodiments, the direction of rotation of the main inlet stirrer is the same as the direction of rotation of the first inlet stirrer.

  In some embodiments, the angular velocity of the first inlet stirrer is equal to the angular velocity of the second inlet stirrer. For example, the apparatus may include a plurality of inlet stirrers, for example, three or more inlet stirrers, and all the inlet stirrers have the same angular velocity.

Schematic diagram of an exemplary glass manufacturing apparatus It is a schematic diagram of a mixing vessel of the prior art, showing the region of the mixing vessel, where the molten glass therein is not sufficiently mixed. FIG. 3 is a plan view of the mixing container of FIG. 2 and shows a glass flow in the mixing container. FIG. 3 is a plan view of a mixing vessel with one inlet stirrer to enhance the function of a main stirrer, according to embodiments described herein. FIG. 3 is a plan view of a mixing vessel with two inlet agitators to enhance the function of a main stirrer according to embodiments described herein. FIG. 4 is an elevational sectional view of the mixing container of FIG. Figure 6 is a plan view of the mixing vessel of Figure 5, showing a modeled molten glass flow according to one possible direction of rotation of the inlet stirrer and the main stirrer. FIG. 6 is a plan view of the mixing vessel of FIG. 5, showing the modeled molten glass flow according to another possible direction of rotation of the inlet stirrer and the main stirrer. Figure 6 is a plan view of the mixing vessel of Figure 5, showing a modeled molten glass flow according to yet another possible direction of rotation of the inlet stirrer and the main stirrer. FIG. 6 is a plan view of the mixing vessel of FIG. 5, showing the modeled molten glass flow according to yet another possible direction of rotation of the inlet stirrer and the main stirrer. FIG. 2 is an elevational schematic view of two side-by-side inlet stirrers, according to embodiments disclosed herein, wherein the inlet stirrers are disposed in an opposed configuration and during rotation of the inlet stirrer; Separated by a certain distance so that multiple stirring blades do not touch FIG. 3 is an elevational schematic view of two side-by-side inlet agitators according to embodiments disclosed herein, wherein the inlet agitators are arranged in an interlocking configuration. FIG. 3 is an elevational schematic view of two side-by-side inlet stirrers, according to embodiments disclosed herein, wherein the inlet stirrers are arranged in an opposing configuration; Although separated by an insufficient distance to prevent contact of the stirrer blades, the rotation of each inlet stirrer is timed such that contact of the stirrer blades of the inlet stirrer does not occur. Three inlet stirrers, two paired inlet stirrers between the main stirrer and the delivery conduit, and a main stirrer positioned opposite the paired stirrer Also, a plan view of an embodiment according to the present disclosure comprising a third stirrer. FIG. 14 is a plan view of the mixing vessel of FIG. 14 with an additional inlet stirrer

  Hereinafter, the apparatus and method will be more fully described with reference to the accompanying drawings, in which exemplary embodiments of the present disclosure are illustrated. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. However, this disclosure may be embodied in many different forms and is not to be construed as limited to the embodiments set forth herein.

  Ranges can be expressed herein as from "about" one particular value, and / or to "about" another particular value. Where a range is represented in this manner, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value above forms another embodiment. Further, it will be appreciated that the endpoints of each range are significant both in relation to the other endpoint and independently of the other endpoint.

  Directional terms as used herein, such as up, down, right, left, front, back, top, bottom ) Are only used with reference to the drawings as shown and are not intended to imply absolute orientation.

  Unless explicitly stated otherwise, it is quite intended that any method described herein be construed as requiring the steps to be performed in a specific order. Not. Therefore, when a method claim does not actually indicate the order in which the steps are to be performed, or in the claims or the description, it is specifically stated that the steps are limited to a specific order. Unless otherwise stated, nothing is intended in any way to imply any order. This is true of any possible implicit basis of interpretation, including: logical issues relating to the organization of steps or operational flows; plain meanings derived from grammatical organization or punctuation; described herein The number or type of the implemented embodiments.

  As used herein, a noun refers to a plurality of objects, unless the context clearly indicates otherwise. Thus, for example, reference to "a" component includes aspects having two or more such components, unless the context clearly indicates otherwise.

  Aspects of the present disclosure include an apparatus for processing a batch into molten glass, and more particularly, an apparatus for processing molten glass. The furnace of the present disclosure can be provided for a wide range of applications for heating gases, liquids and / or solids. In one example, the apparatus of the present disclosure is described with reference to a glass melting system configured to melt a batch into molten glass and transport the molten glass to downstream processing equipment.

  The method of the present disclosure can process molten glass in a variety of ways. For example, the molten glass may be processed by heating the molten glass to a temperature higher than the initial temperature. In a further example, by maintaining the temperature of the molten glass, or by reducing the rate of heat loss that can occur by inputting thermal energy into the molten glass, thereby controlling the rate of cooling of the molten glass, The molten glass may be processed.

  The method of the present disclosure may process the molten glass using a fining vessel or using a mixing vessel, such as a stirring vessel. Optionally, the apparatus operates the glass making apparatus including a thermal management device, an electronic device, an electromechanical device, a support structure, or a transport container (conduit) for transporting the molten glass from one location to another. It may include one or more additional components, such as other components to facilitate.

  Illustrated in FIG. 1 is an exemplary glass making apparatus 10. In some examples, the glass making apparatus 10 can include a glass melting furnace 12 that can include a melting vessel 14. In addition to the melting vessel 14, the glass melting furnace 12 optionally includes one or more additional heating elements, such as heating elements (eg, combustion burners or electrodes) configured to heat the batch and convert the batch to molten glass. Components can be included. In a further example, glass melting furnace 12 may include a thermal management device (eg, an insulating component) configured to reduce heat loss from near the melting vessel. In yet a further example, glass melting furnace 12 may include an electronic device and / or an electromechanical device configured to facilitate melting of the batch material into a glass melt. Still further, the glass melting furnace 12 may include a support structure (eg, a support chassis, support members, etc.) or other components.

  Glass melting vessel 14 is typically made of a refractory material, such as a refractory ceramic material. In some examples, glass melting vessel 14 may be comprised of a refractory ceramic brick, for example, a refractory ceramic brick including alumina or zirconia.

  In some examples, the glass melting furnace can be incorporated as a component of a glass making apparatus configured to make glass ribbons. In some examples, a glass melting furnace of the present disclosure includes a slot draw device, a float bath device, a down draw device (eg, a fusion device), an up draw device, a rolling device, a tube draw device, or other glass ribbon manufacturing device. It can be incorporated as a component of glass manufacturing equipment. For example, FIG. 1 schematically illustrates a glass melting furnace 12 as a component of a fusion downdraw glass making apparatus 10 for fusiondrawing a glass ribbon for later processing into a glass sheet.

  The glass making device (eg, fusion downdraw device 10) may optionally include an upstream glass making device 16 positioned upstream with respect to the glass melting vessel 14. In some examples, a portion or the entirety of the upstream glass making apparatus 16 may be incorporated as part of the glass melting furnace 12.

  As shown in the illustrated example, the upstream glass making apparatus 16 can include a storage bin 18, a batch delivery device 20, and a motor 22 connected to the batch delivery device. Storage bin 18 may be configured to store an amount of batch 24 that can be supplied to melting vessel 14 of glass melting furnace 12 as indicated by arrow 26. In some examples, the batch delivery device 20 can be powered by a motor 22 such that the batch delivery device 20 can deliver a predetermined amount of batch 24 from the storage bin 18 to the melting vessel 14. In a further example, motor 22 powers batch delivery device 20 such that batch delivery device 20 can introduce batch 24 at a controlled rate based on the sensed level of molten glass downstream from melting vessel 14. Can supply. Thereafter, the batch 24 in the melting vessel 14 can be heated to form a molten glass 28.

  Glass manufacturing apparatus 10 can optionally also include a downstream glass manufacturing apparatus 30 positioned downstream with respect to glass melting furnace 12. In some examples, a portion of the downstream glass making apparatus 30 may be incorporated as part of the glass melting furnace 12. For example, a first connecting conduit 32, discussed below, or other portion of the downstream glass making apparatus 30 may be incorporated as part of the glass melting furnace 12. A plurality of elements of the downstream glass making apparatus, including the first connecting conduit 32, may be formed of a noble metal. Suitable noble metals include platinum group metals, or alloys thereof, selected from the group of metals consisting of platinum, iridium, rhodium, osmium, ruthenium and palladium. For example, the downstream components of the glass making apparatus may be formed of a platinum-rhodium alloy containing 70-90% by weight platinum and 10-30% by weight rhodium.

  The downstream glass manufacturing apparatus 30 is disposed downstream from the melting vessel 14 and connected to the melting vessel 14 by the above-described first connection conduit 32 for a first refining (ie, processing) such as a fining vessel 34. A container can be included. In some examples, molten glass 28 can be supplied by gravity from melting vessel 14 to fining vessel 34 by first connecting conduit 32. The molten glass 28 may be propelled from the melting vessel 14 to the fining vessel 34 by gravity, for example, through the internal path of the first connecting conduit 32.

  Within the fining vessel 34, air bubbles may be removed from the molten glass 28 by various techniques. For example, batch 24 may include a polyvalent compound (ie, a fining agent), such as tin oxide, which releases oxygen via a chemical reduction reaction when heated. Other suitable fining agents include, but are not limited to, oxides of arsenic, antimony, iron and cerium. The fining agent is heated by heating the fining vessel 34 to a temperature higher than the melting vessel temperature. Oxygen bubbles generated by one or more temperature-induced chemical reactions of the fining agent rise through the molten glass in the fining vessel and produce the melt in the melting furnace. The gas therein can fuse with the oxygen bubbles generated by the fining agent. The gas bubbles that have become huge can be diverged after rising to the free surface of the molten glass in the fining container.

  The downstream glass manufacturing apparatus 30 can further include a second tempering vessel, such as a mixing vessel 36 for mixing the molten glass, which can be disposed downstream of the fining vessel 34. The glass melt mixing vessel 36 can be used to provide a homogeneous glass melt composition, thereby reducing or eliminating inhomogeneities that may be present in the clarified molten glass exiting the fining vessel. As shown, the fining vessel 34 may be connected to the molten glass mixing vessel 36 by a second connecting conduit 38. In some examples, molten glass 28 may be supplied by gravity from a fining vessel 34 to a mixing vessel 36 via a second connecting conduit 38. The molten glass 28 may be propelled from the fining vessel 34 to the mixing vessel 36 through the internal path of the second connecting conduit 38, for example, by gravity. Although the mixing vessel 36 is shown downstream of the fining vessel 34, it should be noted that the mixing vessel 36 may be positioned upstream of the fining vessel 34. In some embodiments, the downstream glass making apparatus 30 may include a plurality of mixing vessels, for example, a mixing vessel upstream of the fining vessel 34 and a mixing vessel downstream of the fining vessel 34. The plurality of mixing vessels may be of the same design, or they may be of different designs.

  Downstream glass making apparatus 30 may further include another tempering vessel, such as delivery vessel 40, that can be located downstream of mixing vessel 36. The delivery container 40 can condition the molten glass 28 for feeding to a downstream forming device. For example, the delivery container 40 can act as an accumulator and / or flow control device to regulate the continuous flow of the molten glass 28 and supply it to the formation 42 via the outflow conduit 44. As shown, the mixing container 36 may be connected to the delivery container 40 by a third connecting conduit 46. In some examples, molten glass 28 may be supplied by gravity from mixing vessel 36 to delivery vessel 40 via third connecting conduit 46. The molten glass 28 may be propelled from the mixing vessel 36 to the delivery vessel 40 through the internal path of the third connecting conduit 46 by, for example, gravity.

  Downstream glass making apparatus 30 may further include a forming apparatus 48 with the above-described forming body 42 including an inlet conduit 50. Outflow conduit 44 can be positioned to deliver molten glass 28 from delivery container 40 to inflow conduit 50 of forming device 48. In the fusion forming process, the formation 42 includes a trough 52 positioned on the upper surface of the formation and a centralized forming surface 54 that is concentrated along a bottom edge (base) 56 of the formation. Can be. Molten glass delivered to the trough of the formation via the delivery container 40, outflow conduit 44 and inflow conduit 50 flows over the trough wall and along the centralized forming surface 54, the molten glass Runs down as separate streams. These separate streams of molten glass combine along the base 56 below the base 56 to create a single ribbon 58 of glass, which cools the glass and increases its viscosity. The gravitational and traction rolls (not shown) are used to control the dimensions of the glass ribbon 58 as the glass ribbon 58 undergoes a viscoelastic transition to obtain mechanical properties that provide the glass ribbon 58 with stable dimensional characteristics. By applying tension to the glass ribbon by, for example, the drawing process is performed from the base 56. Subsequently, the glass ribbon may be separated into a plurality of independent glass sheets by a glass separation device (not shown).

  In certain glass making systems, the molten glass is routed to the mixing vessel via a conduit open into the mixing vessel near the top of the mixing vessel, and by gravity, the molten glass is It is pulled downward through the mixing container. Typically, for a mixing vessel of the stirring type, the stirrer comprises a stirring blade positioned below the inlet of the stirring vessel. The molten glass near the outlet of this feed conduit is close to a unidirectional Poiseuille flow with a parabolic flow profile. Striae align with streamlines (flow vectors). The molten glass enters the stirring vessel above the stirring blade and rotates about one or more stagnant regions created by the stirring blade below. As a result, incomplete mixing may occur even when the molten glass flows down and interacts directly with the top stirring blade. As a result, not all striae entering the mixing vessel can be completely mixed when leaving the mixing vessel.

  FIG. 2 shows modeled flow data for an exemplary mixing vessel 36 using a conventional stirrer. The mixing container 36 includes a container wall 100 and a stirrer 102 rotatably installed in the mixing container and configured to rotate around a rotation axis 104. Stirrer 102 includes a central shaft 106 and a plurality of stirring blades 108 extending outwardly from shaft 106, with stirring blades 108 disposed along the length of shaft 106. The flowchart of FIG. 2 shows a generally stagnant region 110 of molten glass located above the top blade 108 of the stirrer 102, within which stagnation region, even if the stirrer 102 is rotating. Insufficient mixing of the molten glass occurs. In some instances, unmixed molten glass may exit one or more of these stagnation regions and travel through the remainder of the mixing vessel without being well mixed. is there. For example, unmixed molten glass may move down along shaft 106, or unmixed molten glass may move down along the inside surface of container wall 100. Unmixed molten glass can include heterogeneous molten glass that is trapped in a stream of molten glass being conveyed to the formation.

  FIG. 3 is a partial plan view of a conventional mixing vessel 36 with only one main stirrer 102, as described above with respect to FIG. 2, and illustrates the modeled flow of molten glass as indicated by arrow 120. Show. The stirring blades of the main stirrer 102 are not shown so as not to impair the visibility of the arrow 120 in the flow direction. The main stirrer 102 rotates clockwise as indicated by arrow 122 and the flow direction arrow 120 indicates that the molten glass 28 from conduit 38 (hereinafter referred to as delivery conduit 38) into mixing vessel 36. 4 shows a rough flow pattern of the flow of the molten glass 28 in the mixing container and the flow of the molten glass 28 in the mixing vessel. As shown, in a conventional mixing vessel having only a single central main stirrer, the molten glass contained in the mixing vessel is moved in a single rotational direction ( (Clockwise or counterclockwise rotation). Therefore, mixing may hardly occur in the volume of the mixing container above the uppermost stirring blade of the main stirrer. Mixing in this example would depend entirely on the work of the main stirrer 102.

  Referring now to FIG. 4, another exemplary mixing vessel 36 comprising a vessel wall 200, a main agitator 202 and at least one inlet agitator 204 is shown. More specifically, FIG. 4 illustrates a mixing vessel that includes only a single inlet agitator 204. FIG. 5 illustrates another exemplary mixing vessel 36 that includes two inlet agitators 204. FIG. 6 is a side cross-sectional view of the mixing vessel of FIG. 4 showing a vertical arrangement of the main stirrer 202 and at least one inlet agitator 204 relative to the free surface 206 of the molten glass 28 in the mixing vessel. is there. Although the mixing vessel 36 of FIGS. 4 and 5 is illustrated as having one and two inlet stirrers 204, respectively, the mixing vessel 36 may include more than two inlet stirrers 204. .

  The main stirrer 202 includes a main stirrer shaft 208 and one or more main stirrer blades 210 extending from the main stirrer shaft 208. One or more main stirring blades 210 are configured to sink below the free surface 206 of the molten glass 28 in the mixing vessel 36 during operation of the mixing vessel. Main agitator 202 may include, for example, a plurality of main agitator blades 210, which are arranged in a vertically extending array, and also extend outward from main agitator shaft 208. In the exemplary embodiment, mixing vessel 36 is a cylindrical vessel, and the vessel wall defines a cylindrical interior volume. Thus, in the embodiment of FIGS. 4 and 5, the main agitator shaft 208 may be centrally positioned and rotatably mounted within the agitating vessel 36. That is, the main stirrer shaft 208 is concentric with the inner surface of the container wall 200, for example, the mixing container wall 200, such that the central longitudinal axis 212 of the mixing container 36 is the rotation axis of the main stirrer shaft 208. It is at the same position as the central longitudinal axis 214 of some main agitator shaft 208. In the example where the mixing vessel 36 is a cylindrical mixing vessel, the stirring blade 210 causes the incoming molten glass flow to flow as the molten glass moves between the delivery conduit 38 and the outlet conduit 46. It is configured to sweep around the wall of the mixing vessel to prevent bypassing the blade (see FIG. 6). For example, in some embodiments, the outermost reach of the agitating blade 210 is within 3 cm of the inner surface of the vessel wall, for example, about 1.6 cm to about 3 cm or about 1.6 cm to about 25 cm, or about 1. It can be from 6 cm to about 2 cm, including all ranges and subranges therebetween. The one or more stirring blades 210 extend outward from the axis of rotation 214 by a distance dm. The main stirrer shaft 208 can also be connected to a drive assembly (not shown) that includes an electric motor that can be connected to the main stirrer shaft by, for example, a belt, chain, or other drive connection means.

  As mentioned above, the mixing vessel 36 may include one or more inlet agitators 204. Each inlet agitator 204 includes an inlet agitator shaft 216 and may further include a plurality of stirring blades 218 extending from the inlet agitator shaft 216. Each inlet agitator shaft 216 is rotatable about a rotation axis 222 that is offset from the main stirrer shaft rotation axis 214 by a distance da. The distance da may be the same for each inlet stirrer 204, or the distance da may vary from inlet to inlet stirrer. In some embodiments, the distance da may be the same for some inlet agitators 204 and different for other inlet agitators. Stirrer blades 218 may be arranged, for example, as a vertically extending array, whereby stirrer blades 218 are arranged along the length of inlet stirrer shaft 216. In other embodiments, each inlet agitator 204 may include only a single stirring blade, for example, a spirally wound stirring blade (eg, a screw). 4 to 6, the rotation axis 222 of the inflow-side stirrer shaft 216 is separated from the rotation axis 214 of the main stirrer shaft 208 by a distance da smaller than the distance dm. Further, the entirety of the inflow stirrer shaft 216 and the stirrer blades 218 (eg, the inflow stirrer 204) may be within the sweep range of the blade 210 of the main stirrer 202. That is, when the main stirrer 202 rotates, the one or more blades 210 sweep an arc having a radius of dm. The projection area of this arc is a cylindrical volume, and in some embodiments, the inlet stirrer 204 (inlet stirrer shaft 216 and stirrer blades 218) is entirely formed by the stirrer blades of the main stirrer 202. It may be within this projected cylindrical volume that is swept. The cylindrical volume swept by the stirring blade 210 is smaller than the total volume of the mixing vessel 36, and the inflow-side stirrer 204 (the inflow-side stirrer shaft 216 and the stirring blade 218) as a whole is It will be clear that it is within the overall cylindrical volume.

  As is clear from FIG. 6, each inflow-side agitator 204 is positioned such that the lowermost reach of the inflow-side agitator 204 is positioned above the uppermost agitating blade 210 of the main agitator 202. Is done. That is, each inflow side stirrer 204 occupies the volume in the container 36 between the uppermost stirring blade 210 of the main stirrer 202 and the mixing container cover 225. The rotation axis 222 of each inflow-side agitator 204 extends parallel to the rotation axis 214 of the main agitator shaft 208 and is offset from the rotation axis 214 by a distance da smaller than dm. When the stirrer 204 extends below the uppermost stirring blade 210 of the main stirrer 202, the inflow-side stirrer 204 interferes with the rotation of the main stirrer 202. This can be confirmed in another way by imagining a horizontal plane 224 (see FIG. 6) extending through the mixing vessel 36. Horizontal surface 224 may be, for example, perpendicular to central longitudinal axis 212.

  Consider the case where the uppermost stirring blade of the main stirrer 202 exists below the horizontal plane 224. Further, consider the case where none of the one or more inflow-side agitators 204 extend below the horizontal plane 224. Thus, the horizontal surface 224 divides the volume of the mixing container into an upstream volume 226 and a downstream volume 228, and one or more inlet agitators 204 are positioned within the upstream volume 226 of the mixing container, It does not extend into the downstream volume 228 of the mixing vessel.

  Also, consider a first vertical surface 230 (see FIG. 4) extending through the mixing vessel 36, wherein the axis of rotation 214 resides entirely within the first vertical surface 230. Further consider the case where the first vertical surface 230 can be perpendicular to the central longitudinal axis 232 of the delivery conduit 38. In some embodiments, such as the embodiments of FIGS. 4 and 5, the at least one inlet agitator 204 is such that the at least one inlet agitator 204 is located between the main agitator shaft 208 and the delivery conduit 38. And so on. In other words, the at least one inlet agitator 204 is on the same side of the first vertical surface 230 as the delivery conduit 38.

  Next, the delivery conduit 38 is positioned within the mixing vessel, rotatable about a rotation axis offset from the rotation axis of the main stirrer 202 by a distance da, and on a first vertical surface 230. Consider a second inlet agitator 204, positioned on the same side (see FIG. 5), and with respect to a second vertical surface 233 perpendicular to the first vertical surface 230, the central longitudinal length of the delivery conduit 38. The direction axis 232 is present entirely in the second vertical plane 231, and the rotation axis of the first inflow-side agitator and the rotation axis of the second inflow-side agitator are in the second direction. Let us consider the case where it is on the opposite side of the vertical plane 233. For example, in some embodiments, the first inlet stirrer 204 and the second inlet stirrer 204 may be equidistant from the second vertical surface 233 (see FIG. 5).

  FIG. 7 shows a modeled molten glass flow in the exemplary mixing vessel 36 embodied in FIG. 5 that includes two inlet agitators 204. FIG. 7 shows that the flow of the molten glass in the mixing container 36 is disturbed by the rotation of the inflow-side stirrer. That is, the flow of the molten glass above the stirring blades of the main stirrer 202 becomes more disordered, thereby enhancing mixing. For clarity, the stirring blades of both the main stirrer 202 and the inlet stirrer 204 have been omitted. Only the shaft is shown. In the embodiment of FIG. 7, the main stirrer 202 rotates clockwise as indicated by arrow 234. Furthermore, each inflow-side agitator also rotates clockwise. However, it will be clear that the main stirrer 202 and each inflow side stirrer 204 can also rotate in a counterclockwise direction, respectively. As shown, the molten glass entering the upstream volume 226 is subject to flow disturbances by the inlet agitator 204.

  In the embodiment of FIG. 8, the inflow-side agitator 204 is rotating in the opposite direction. That is, while one inflow-side agitator 204 rotates clockwise, the second inflow-side agitator 204 rotates counterclockwise. Although the main stirrer 202 is rotating in a clockwise direction as indicated by the arrow 234, it will be apparent that the main stirrer 202 can also rotate counterclockwise. Again, it is shown that flow disturbances occur in the mixing vessel, especially in the upstream volume 226.

  In still another embodiment shown in FIG. 9, both inflow side agitators 204 rotate in the opposite direction as in the embodiment of FIG. 8, but in this embodiment, the rotation direction is switched. Instead of the counter-clockwise rotation of the "top" inlet stirrer 8 in FIG. 9, the top inlet stirrer rotates clockwise in FIG. 9 and the bottom inlet stirrer rotates counterclockwise. It is rotating around. The main stirrer 202 is rotating clockwise.

  Finally, in FIG. 10, the main agitator 202 is rotating clockwise, as indicated by arrow 234, and the two inflow agitators 204 are rotating in opposite, counterclockwise directions. 7, 8 and 9, flow disturbances occur in the area of the inlet agitator 204 (upstream volume 226), which causes the main agitator 202 to mix molten glass in the downstream volume 228. Reduce the work that needs to be performed.

  11, 12 and 13 show various arrangements of paired inlet agitators 204. For example, in the embodiment of FIG. 11, two inlet stirrers 204 are shown, which are separated by a distance ds separating the respective rotation axes 222 of the inlet stirrers from the length dn of the individual stirring blades 218. It is arranged so as to exceed twice (the stirring blade length dn is measured from the rotation axis 222 of each shaft to the tip of the stirring blade 218). Therefore, although the individual stirring blades are positioned facing each other, sufficient clearance is provided so that these facing blades do not contact each other. For example, opposing agitating blades may be separated by a distance of about 1.2 cm to about 2.5 cm. These inlet stirrers may be the same, or they may have different designs.

  In the embodiment of FIG. 12, the inlet stirrer 204 is arranged in a vertically offset configuration, with the individual stirring blades 218 of the inlet stirrer vertically engaging. Thus, the distance ds between the rotation axes 222 of each inlet stirrer is less than twice the length dn of the individual stirring blades, but exceeds the length dn of a single stirring blade, ie dn <ds <2 · dn.

  In the embodiment of FIG. 12, the inlet stirrers are arranged facing each other, similar to those shown in FIG. 11 (aligned vertically), The distance between the rotating shafts 222 is such that the distance ds between the rotating shafts 222 of the inlet agitator is less than twice the length dn of the individual stirring blades 218, but as shown with respect to FIG. In addition, the length of the single stirring blade exceeds the length dn, that is, dn <ds <2 · dn. For the purposes of this disclosure, the stirrer blades of these two inlet stirrers are referred to as “interwinned”. In the present embodiment, the rotation of the entangled inflow-side stirrer is controlled so that contact between the stirring blade of one inflow-side stirrer and the stirring blade of the other adjacent inflow-side stirrer does not occur. Is set. For example, the relative rotational phase between the two stirrers can be 45 °, for example, from about 40 ° to about 50 °.

  In yet another embodiment, three or more inlet agitators 204 may be included in the mixing vessel 36. For example, FIG. 14 shows an embodiment with three inlet agitators 204. The additional inflow stirrer 204 may be substantially the same as or identical to the inflow stirrer 204 already described, for example, as described above, only the arrangement differs. For example, the additional inlet agitator 204 may be positioned on the opposite side of the plane 230 from the delivery conduit 38 (see FIG. 4). In the embodiment of FIG. 14, the third inlet stirrer 204 includes first and second inlets positioned on the first vertical surface 230 between the first vertical surface 230 and the delivery conduit 38. It is positioned on the side opposite to the agitator 204. Further, the third inlet stirrer 204 may be positioned such that the rotation axis 222 of the third inlet stirrer intersects the central longitudinal axis 232 of the delivery conduit 38, but in other embodiments. It is not necessary to arrange this way. FIG. 15 illustrates the use of a plurality of additional inlet agitators disposed around the main agitator 202. In the embodiment of FIG. 15, the rotation shafts 222 of the inflow-side agitators 204 of the plurality of inflow-side agitators are offset from the rotation shaft 214 of the main agitator 202 by a uniform distance da less than dm. However, such a uniform offset is not required, so in other embodiments da may vary from inlet stirrer to inlet stirrer.

  The table below shows an exemplary mixing vessel with inlet agitators rotating in different rotation directions (Rot. Dir.) Relative to each other (co-rotation (Co) or counter-rotation (X)). It provides modeled data showing specific performance characteristics, wherein the main agitator has a rotational speed expressed in revolutions per minute (RPM) and a relative rotation between the two inlet agitators. Under conditions where the phase fluctuates. In each example, the main stirrer rotated clockwise at a rotation speed of 11 RPM. The stirring effectiveness index (SEI) is determined using a similarly configured stirrer (main stirrer and inlet stirrer) of a graduated simulated mixing container made of optically clear acrylic. Was derived by optical analysis. Here, paraffin selected to mimic the viscosity of the molten glass was flowed through the mixing vessel to simulate the flow of the molten glass. Dye was then injected into the paraffin stream, and the stream was imaged using a charge coupled device (CCD) camera and analyzed with suitable imaging software. The output of each pixel was amplified, digitized, and scaled to 8-bit gray scale (ranging from black 0 to white 255). The resulting data was encoded as a numeric array having width and height dimensions equal to the number of pixels in each direction on the CCD into a file suitable for characterization. Quantitative information was obtained on specific features in the image, defined for example by edge, color, intensity, feature size, fractal dimension, and location. By combining sequences of multiple images of the same region taken at different times, additional time derivative information is determined for the feature, including but not limited to velocity, acceleration, and growth and / or decay velocity it can. Using these techniques, numerical scales, stirring effectiveness can be evaluated relative to various mixing vessel designs.

  The stirring effectiveness index is the product of the full width at half maximum (FWHM) of the residence time distribution (the variance term) and the ratio of the high-frequency bandpass image intensity to the unfiltered image intensity (the homogeneity term). The unit of SEI is seconds, which is in fact the temporal dispersion of the mixing vessel, corrected for the inhomogeneity introduced by the mixing vessel. For example, the variance terms can be obtained from a series of line scan images of the simulated mixing vessel. During the measurement, the flow rate is kept constant, so that the time measurement can be used as a proxy for volume. Using suitable imaging software, an average intensity profile of a line scan image can be derived. For example, the average intensity of each line of pixels can be calculated and plotted as a function of its step (time). The resulting profile shows the distribution of absorption as a function of time, which is approximately a lognormal distribution. The variance term is the FWHM of this distribution.

  The homogeneity term is a measure of the contrast in the image. The purpose is to subtract the dispersion of the dye and to know the dispersed dye. Subsequently, the FWHM region imaged for the variance term is analyzed. The leading edge of the area is extended to 20% of the total height and the integrated intensity of the area is measured. Next, a low-pass filter is applied. The homogeneity term is then equal to a fraction of the total intensity, expressed as the integral of the intensity in the low-pass region.

  The data in the table below shows advantageous stirring effectiveness for a plurality of inlet agitators rotating in the same phase and rotating with the main stirrer, but other configurations are possible and the stirring effectiveness is It drops at the same time. “Phase” represents the relative rotational speed of the inflow-side agitator, and “in phase” represents that both inflow-side agitators rotate at the same rotational speed, and the agitating blade is as shown in FIG. (For comparison, a phase difference of 45 ° is considered to be the same as that of the stirring blade in FIG. 13).

  It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the present disclosure without departing from the spirit and scope of the invention. Accordingly, the present disclosure is intended to cover such modifications and variations of such embodiments as long as they come within the scope of the appended claims and their equivalents.

  Hereinafter, preferred embodiments of the present invention will be described separately.

Embodiment 1
An apparatus for tempering molten glass,
The above devices are:
container;
A main stirrer positioned within the vessel and rotatable about a first axis of rotation, the main stirrer being coupled to a main stirrer shaft and a distance dm relative to the first axis of rotation; A main stirrer comprising: a main stirrer blade extending outwardly from the main stirrer shaft; and positioned within the vessel and offset from the first axis of rotation by a distance da less than the dm. An apparatus comprising a first inlet agitator rotatable about a second axis of rotation.

Embodiment 2
2. The embodiment of claim 1, wherein the top main stirring blade is positioned below the horizontal plane with respect to a horizontal plane extending through the vessel, and the first inlet agitator does not extend below the horizontal plane. apparatus.

Embodiment 3
Further comprising a delivery conduit open into the container and configured to deliver the molten glass to the container;
The delivery conduit has a central longitudinal axis;
With respect to a first vertical plane extending through the container perpendicular to the central longitudinal axis of the delivery conduit, the first axis of rotation resides entirely within the first vertical plane. 3. The apparatus of embodiment 2, wherein the first inlet agitator is positioned on the same side of the first vertical plane as the delivery conduit.

Embodiment 4
A second inlet-side stirrer,
The second inlet-side stirrer is positioned within the container, is rotatable about a third axis of rotation offset by the distance da from the first axis of rotation, and is rotatable about the first vertical plane. Are positioned on the same side as the delivery conduit,
With respect to a second vertical plane perpendicular to the first vertical plane, the central longitudinal axis of the delivery conduit lies entirely within the second vertical plane, the second rotational axis and 4. The apparatus of embodiment 3, wherein the third axis of rotation is opposite the second vertical plane.

Embodiment 5
4. The device of embodiment 3, further comprising a second inlet agitator positioned on the first vertical surface opposite the delivery conduit.

Embodiment 6
The apparatus of embodiment 1, further comprising a plurality of the inlet agitators.

Embodiment 7
The container is cylindrical,
The device of embodiment 1, wherein the first axis of rotation is coincident with the central longitudinal axis of the container.

Embodiment 8
An apparatus for tempering molten glass,
The above devices are:
container;
A main stirrer positioned within the vessel and rotatable about a first axis of rotation, the main stirrer being coupled to a main stirrer shaft and a distance dm from the first axis of rotation A main stirrer comprising a top main stirrer blade extending outwardly from the main stirrer shaft;
A first inlet agitator positioned within the vessel and rotatable about a second axis of rotation offset from the first axis of rotation;
An apparatus, wherein with respect to a horizontal plane extending through the vessel, the uppermost main stirring blade is positioned below the horizontal plane and the first inlet agitator does not extend below the horizontal plane.

Embodiment 9
The first inlet stirrer is positioned within the upstream volume of the vessel;
Embodiment 9. The apparatus of embodiment 8, wherein the top agitating blade is positioned within a downstream volume of the vessel.

Embodiment 10
The upstream volume and the downstream volume are cylindrical volumes,
Embodiment 10. The device of embodiment 9, wherein a central longitudinal axis of the upstream volume coincides with a central longitudinal axis of the downstream volume.

Embodiment 11
Embodiment 9. The apparatus according to embodiment 8, comprising a plurality of said inlet agitators.

Embodiment 12
Each of the plurality of inflow-side agitators is positioned within the container and is rotatable about a rotation axis that is offset from the first rotation axis by a distance da less than the dm. Embodiment 12. The apparatus of embodiment 11, wherein

Embodiment 13
Further comprising a delivery conduit open into the container and configured to deliver the molten glass to the container;
The delivery conduit has a central longitudinal axis;
With respect to a first vertical plane extending through the container perpendicular to the central longitudinal axis of the delivery conduit, the first axis of rotation resides entirely within the first vertical plane. 9. The apparatus of embodiment 8, wherein the first inlet agitator is positioned on the same side of the first vertical plane as the delivery conduit.

Embodiment 14
A second inlet-side stirrer,
The second inlet stirrer is positioned within the container and is rotatable about a third axis of rotation offset from the first axis of rotation, wherein the delivery of the first vertical surface is controlled. Positioned on the same side as the conduit,
With respect to a second vertical plane perpendicular to the first vertical plane, the central longitudinal axis of the delivery conduit lies entirely in the second vertical plane and the third axis of rotation is 14. The apparatus according to embodiment 13, wherein the apparatus is positioned on the opposite side of the second vertical plane from the second axis of rotation.

Embodiment 15
Embodiment 15. The apparatus of embodiment 14, wherein the second axis of rotation and the third axis of rotation are equidistant from the second vertical plane.

Embodiment 16
A method for tempering molten glass,
The above method:
Flowing molten glass from a delivery conduit into a container, the container including an upstream volume and a downstream volume relative to the molten glass flow;
Stirring the molten glass in the upstream volume with a first inlet stirrer rotatable about a rotation axis; and the molten glass in the downstream volume with the first inlet stirrer. Stirring with a main stirrer rotatable about a rotation axis parallel to the rotation axis, said main stirrer comprising a top stirrer blade,
A method wherein, with respect to a horizontal plane extending through the vessel, the uppermost stirring blade is positioned below the horizontal plane and the first inlet agitator is positioned generally above the horizontal plane.

Embodiment 17
The uppermost stirring blade has a length dm that is a maximum extension range of the uppermost stirring blade from the rotation axis of the main stirrer,
17. The method of embodiment 16, wherein an offset between the rotation axis of the first inlet stirrer and the rotation axis of the main stirrer is less than the dm.

Embodiment 18
Agitating the molten glass using a second inflow-side agitator having a rotating shaft,
The second inlet stirrer is positioned generally above the horizontal plane;
Embodiment 18. The method of embodiment 17, wherein the offset between the rotation axis of the second inlet stirrer and the rotation axis of the main stirrer is less than the dm.

Embodiment 19
With respect to a vertical plane perpendicular to the central longitudinal axis of the delivery conduit, the central longitudinal axis of the container lies entirely in the vertical plane, and the first inlet agitator and the second inlet 19. The method of embodiment 18, wherein a side agitator is positioned between the vertical surface and the delivery conduit.

Embodiment 20
20. The method of embodiment 19, wherein the direction of rotation of the first inlet stirrer is the same as the direction of rotation of the second inlet stirrer.

Embodiment 21
21. The method of embodiment 20, wherein the direction of rotation of the main inlet stirrer is the same as the direction of rotation of the first inlet stirrer.

Embodiment 22
20. The method of embodiment 19, wherein the angular velocity of the first inlet stirrer is equal to the angular velocity of the second inlet stirrer.

DESCRIPTION OF SYMBOLS 10 Glass manufacturing apparatus 12 Glass melting furnace 14 Melting container 16 Upstream glass manufacturing apparatus 18 Storage bin 20 Batch delivery device 22 Motor 24 Batch 26 Arrow 28 Molten glass 30 Downstream glass manufacturing apparatus 32 First connection conduit 34 Refining vessel 36 Mixing Vessel 38 Second connecting conduit, delivery conduit 40 Delivery container 42 Mold 44 Outflow conduit 46 Third connecting conduit 48 Forming device 50 Inflow conduit 52 Trough 54 Concentrated forming surface 56 Mold bottom edge, base 58 Glass ribbon REFERENCE SIGNS LIST 100 container wall 102 stirrer 104 rotation axis 106 central shaft 108 stirring blade 110 molten glass stagnation region 120 arrow 122 arrow 200 container wall 202 main stirrer 204 inflow-side stirrer 206 free surface of molten glass 208 main stirrer shaft 210 may Stirring blade, top stirring blade 212 Central longitudinal axis of mixing vessel 36 Central longitudinal axis of main stirrer shaft 208, main stirrer shaft rotation axis 216 Inlet-side stirrer shaft 218 Stirring blade 222 Inflow stirrer shaft 216 Axis of rotation of inlet side agitator 204 224 horizontal plane 225 mixing vessel cover 226 upstream volume 228 downstream volume 230 first vertical plane 232 central longitudinal axis of delivery conduit 38 233 second vertical plane 234 arrow

Claims (9)

An apparatus for tempering molten glass,
The device is:
container;
A main stirrer positioned within the vessel and rotatable about a first axis of rotation, the main stirrer comprising: a main stirrer shaft; and a distance dm relative to the first axis of rotation. A main stirrer comprising: a top stirrer blade extending outwardly from the main stirrer shaft; and positioned within the vessel and offset from the first axis of rotation by a distance da less than the dm. An apparatus comprising a first inlet agitator rotatable about a second axis of rotation.   2. The horizontal stirrer of claim 1, wherein the top main stirring blade is positioned below the horizontal plane with respect to a horizontal plane extending through the vessel, and the first inlet agitator does not extend below the horizontal plane. apparatus. A delivery conduit open into the container and configured to deliver the molten glass to the container;
The delivery conduit comprises a central longitudinal axis;
With respect to a first vertical plane extending through the container perpendicular to the central longitudinal axis of the delivery conduit, the first axis of rotation resides entirely within the first vertical plane. 3. The apparatus of claim 2, wherein the first inlet agitator is positioned on the same side of the first vertical plane as the delivery conduit. A second inlet-side stirrer,
The second inlet stirrer is positioned within the vessel, is rotatable about a third axis of rotation offset by the distance da from the first axis of rotation, and includes a first vertical plane. Are positioned on the same side as the delivery conduit,
With respect to a second vertical plane perpendicular to the first vertical plane, the central longitudinal axis of the delivery conduit lies entirely within the second vertical plane and the second axis of rotation and 4. The apparatus of claim 3, wherein the third axis of rotation is opposite the second vertical plane.   4. The apparatus of claim 3, further comprising a second inlet agitator positioned on the opposite side of the first vertical plane from the delivery conduit. An apparatus for tempering molten glass,
The device is:
container;
A main stirrer positioned within the vessel and rotatable about a first axis of rotation, the main stirrer comprising a main stirrer shaft and a distance dm relative to the first axis of rotation; A main stirrer comprising a top main stirrer blade extending outwardly from the main stirrer shaft;
First and second inflow-side agitators positioned within the vessel and rotatable about respective axes of rotation offset from the first axis of rotation, the first and second inlet stirrers comprising: Has a stirring blade of length dn with respect to the respective rotation axis, separated by a distance ds,
An apparatus wherein dn <ds <2dn . The first inlet stirrer is positioned within an upstream volume of the vessel;
The apparatus of claim 6, wherein the top agitating blade is positioned within a downstream volume of the vessel. A method for tempering molten glass,
The method is:
Flowing molten glass from a delivery conduit into a container, wherein the container includes an upstream volume and a downstream volume with respect to the molten glass flow;
Stirring the molten glass in the upstream volume with a first inlet stirrer rotatable about a rotation axis ;
Before SL molten glass in the downstream volume, comprising the steps of stirring at rotatable main agitator around a rotation axis parallel to the rotation axis of the first inlet-side agitator, the main agitator Comprising a step, comprising a top stirring blade,
With respect to a horizontal plane extending through the vessel, the uppermost stirring blade is positioned below the horizontal plane, the first inlet agitator is positioned generally above the horizontal plane ; and
The uppermost stirring blade includes a length dm that is an extension range of the uppermost stirring blade from the rotation axis of the main stirrer, and the rotation shaft of the first inflow-side stirrer and the main shaft have the same length. A method wherein the offset between the agitator and the axis of rotation is less than the dm . Agitating the molten glass using a second inflow-side agitator having a rotating shaft,
The second inlet stirrer is positioned generally above the horizontal plane;
9. The method of claim 8 , wherein an offset between the rotation axis of the second inlet stirrer and the rotation axis of the main stirrer is less than the dm.

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