KR19990063970A - Method and apparatus for modifying and homogenizing glass melt - Google Patents

Abstract

The present invention relates to a method in which the molten glass is modified and added to the base glass structure to change its properties that occur in flowing in a stream in a single direction through a substantially horizontal channel with the modifying material. The horizontal and vertical distribution of the deformable material in the glass stream is effective in isolation. The molten glass with the deformation material homogeneously distributed thereon is then delivered to the forming facility.

Description

Method and apparatus for modifying and homogenizing glass melt

The concept of adding colorants to the molten base glass is already known except that it is actually applied in the field of container glass (sometimes referred to as "forehearth color") rather than in the field of rigid glass. This is usually greater than that for container glass and float glass, as the quality, special homogeneity and bubble requirements for rigid glass continue to be more stringent. In particular, apart from the "artistic" form product, colored flat glass and especially flat float glass need to have a uniform pale color throughout the area and therefore the added colorant material is very evenly distributed in the glass. Needs to be. It is necessary to influence the addition and partitioning in such a way that no water-insoluble bubbles occur as a result. Nevertheless, there is proposed to add colored material to the molten base glass construct to produce colored flat glass. If this is done successfully, it may be necessary for the transition time of the flat glass production colored from clean and flat glass or for the effect of changing from one color to another when the different components are melted in the base melting tank or furnace. Can be gradually reduced.

EP 0 599 403A discloses a batch for producing colored glass containers, EP 0 556 576A discloses a color batch for window glass or container glass constructs and EP 0 275 534A for producing colored flat glass. Deployment is disclosed. All of the above batches have several modes of operation for mixing additional colorant material in the molten glass. EP 0 599 403A has pulsed bubblers and in particular EP 0 556 576A, which relates to the generation of bubbles, there is a similar arrangement of mechanical stirrers. EP 0 275 534A also has a similar arrangement of mechanical stirrers. It will be appreciated that each of the agitators in this arrangement will add some form of stirring operation to the glass. One form of stirring operation does not achieve the required uniformity of the distribution of the colorant material in the glass.

The present invention relates to the production of glass, in particular to a method of modifying the base glass for conveying a desired color, for example for changing its properties.

DESCRIPTION OF THE EMBODIMENTS An embodiment according to the present invention will now be described with reference to the accompanying drawings.

1 schematically shows a glass melting furnace or tank,

2 shows schematically a vertical section through a feeder deforming the material;

3 shows schematically a vertical section through an alternative form of a feeder deforming the material, FIG.

4 schematically shows a vertical section through another form of feeder for deforming the material;

5 schematically illustrates a glass melting furnace or tank,

6 schematically illustrates the entrance of a useful float glass or float bath.

According to the present invention, there is provided a feature comprising flowing a molten base glass in a substantially unidirectional direction in a stream along a substantially horizontal channel, and adding the modifying material to the horizontally flowing molten base glass. A method of modifying a base glass, the method comprising: distributing a deformable material vertically in a molten glass and separately distributing a deformable material horizontally in a molten glass having a dispensing component transversely in the direction of travel of the stream. And delivering a stream of molten glass having a substantially homogeneously distributed strain material to the forming facility.

The modifying material can be added to the molten base glass and then distributed vertically to the molten glass. The vertical dispensing can be effective by stirring the horizontal flow molten base glass carrying the deformable material to generate relative vertical motion in the glass.

Vertical agitation can be formed by rotating a vertical axis that carries a substantially helical blade that is at least partially recessed in the molten glass. The mechanical stirrer may consist of a refractory metal and may preferably be a refractory metal such as platinum.

The modifying material can be distributed horizontally to the molten glass by stirring the horizontal flow molten base glass carrying the modifying material to produce a relative horizontal motion in the molten glass having the components transverse to the direction of travel of the stream.

Horizontal agitation can preferably be performed by rotating a substantially vertical axis carrying the paddle blades at least partially recessed in the molten glass.

Preferred agitation to generate the relative vertical motion is performed before separating the separate agitation into a relative horizontal motion. That is, vertical agitation is effective for the top stream of horizontal agitation to the stream flow of molten glass.

The base glass may be a substantially clean glass or a thinly colored glass and the modifying material may be a colorant material to modify the thin color of the thinly colored base glass or to produce a thin colored glass.

The modifying material is in molten form as it is added to the molten base glass. The upper surface of the substantially horizontal flow stream of the molten base glass can be slid. Alternatively, it can be added below the surface of the molten base glass, for example by introducing it from a member in which the feed end is recessed in the molten glass, and in such a way that it is distributed vertically to the molten glass as it is added. Can be.

The forming facility may be a flat glass (particularly float glass) forming facility, and the method includes forming molten glass with a substantially homogeneously distributed strain material in the flat glass (particularly float glass). In addition, the present invention provides flat glass (particularly float glass) produced by the process.

Another feature of the invention is an apparatus for adding a straining material to a substantially horizontally flowing stream of molten base glass, the apparatus comprising: a feed member having a lower portion and an outlet of the straining material for sinking into the molten glass; (S) means for feeding the deformable material into the feed member for protruding through the outlet into the molten glass stream below, the outlet extending with a vertical component to distribute the deformable material beyond at least a major portion of the stream depth. A deformable material adding device is provided.

The outlet comprises a series of apertures on one side of the feed member which are in contact in the direction of travel of the stream when in use and preferably can be arranged, for example, in a substantially vertical line. Preferably the deformable material protrudes from the outlet in the molten state and the device comprises a melter for melting the deformable material and is delivered to the feed member in the molten state. Preferably the melter comprises a filter device to prevent unwanted problems being delivered to the feed member. The supply member is conveniently a pipe.

The glass melting furnace or tank shown schematically in FIG. 1 comprises an upper stream section 1 having a melting zone 2 and a restriction zone 3 connected to the working end 5 by a waist 4. The conduit 6 is guided from the operating end 5 to the outlet 7 at the inlet for convenience. The batch material is fed into the melting zone 2 in a known manner and then melted there to form a molten glass that is confined in the restricted zone 3, ie bubbles are removed. The molten glass passes through the waist 4 to the operating end 5 and then along the conduit 6 to the outlet 7 which regulates the glass state generated at the operating end 5 and the conduit 6. do. Those skilled in the art will generally understand that the stuck boundaries between the melting, limiting and regulating zones are not accurate.

Substantially the waist 4, the operating end 5 and the conduit 6 are melted in the tank 1 so that a limited melt base flows in the stream in a single direction towards the outlet 7 without any substantial return stream flow. Through this, a substantial horizontal channel is formed. Furthermore, the molten glass stream preferably flows in a single direction over the upper stream spacing of the waist 4, for example, approximately equal to the stream width, in the lower stream portion of the confined region 3. The feeder 8 is located at the waist 4 by adding a modifying material, for example a colorant, into the horizontal flow molten base glass and the modifying material is located towards the upper stream end of the working end 5. By vertically melted glass. The agitator 9 is at least partially in the molten glass such that the rotation of the axis is affected by the movement of the horizontal flow molten base glass carrying the deformation material to generate relative vertical motion in the molten glass in which the deformation material is vertically distributed. It includes a vertical axis for carrying the helical blade soaked with.

Agitator 10 designed for dispensing the deformation material horizontally in the molten glass with components that traverse the direction of the stream, ie laterally or transversely, in the direction of the lower stream of the stirrer 9 and the upper stream end of the conduit 6. ) Is additionally. The horizontal dispensing is carried out separately from the vertical dispensing effected by the helical stirrer 9. Horizontally flowed molten base carrying the deformation material to cause relative horizontal motion in the molten glass with components transversely in the direction of movement of the spring in which the rotation of the axis distributes the deformation material across the width of the stream. The stirrer 10 includes a vertical axis that carries a substantially vertical paddle blade in the molten glass that is at least partially wetted so as to be affected by the movement of the.

The helical stirrer 9 and the paddle stirrer 10 are each in their original known form and are suitable refractory materials and are preferably refractory metals such as platinum. The helical stirrer 9 is shown in a pair rotated in the same direction (indicated by an arrow as counterclockwise) and the paddle stirrer by driving the molten glass between the helical stirrer 9 and the paddle stirrer 10. 10 is shown in pairs rotated in opposite directions (indicated by arrows). However, a number of stirrers (along and across the stream) and their direction of rotation can be selected to meet particular requirements except that they effectively cover the entire width of the molten glass stream at the stirring position. If not impossible, in practice the complete horizontal or full vertical relative motion in the molten glass can be difficult to obtain by each other stirrer and the relationship of the horizontal and vertical motion is intended to indicate the prevailing horizontal and vertical motion respectively. . In addition, a person skilled in the art can separately (preferably) influence the vertical and horizontal movements by the different stirring operations produced by the stirrer 9 and the stirrer 10 so that a relatively simple overall arrangement is achieved. It can be used to compare a number of more complex batches of the same complex stirrer as is sometimes used in the manufacture of glass containers.

In the FIG. 1 embodiment, the glass temperature at the location of the stirrer 9 may typically range from 1200 ° C to 1450 ° C, for example about 1300 ° C. The molten glass temperature at the location of the stirrer 10 may range from 1150 ° C to 1400 ° C, for example, 1280 ° C. The longitudinal spacing between the position of the stirrer 9 and the position of the stirrer 10 is sufficient to enhance mixing, and from this point of view, may be at least the width of the molten glass stream, which may typically range from 1 m to 4 m. However, it is preferred that the gap length makes it possible, in particular, to avoid substantial countercurrent action between the agitating operations in which bubbles are generated. The spacing is therefore preferably greater than the width of the molten glass stream, ie the working end 5, and may typically be in the range of 2 m to 8 m, for example 4 m. The depth of the molten glass stream is the same as that matched in the unidirectional flow, and typically ranges from 200 mm to 800 mm, e.g., long conduits (e.g. 50 m long) and doubles about 500 mm or short in the stirring position. Conduit (eg, 10 m long) and doubled about 250 mm.

The position of the stirrer 9 is not particularly important, but may be a molten glass stream, ie a lower stream away from the feeder 8 which is approximately equal to the width of the working end 5.

1 schematically shows three feeders 8 spaced beyond the width of the waist 4, typically having a molten glass temperature in the range of 1200 ° C. to 1480 ° C., for example, about 1320 ° C. FIG.

Appropriate number of feeders may be provided and the feeders may be in any suitable form. Preferably the added material is in molten form as it is added to the molten base glass.

One simple form of the feeder is shown schematically in FIG. 2. 2 includes a vertical tube 11 having a panel 12 at the top. The bottom of the tube 11 is soaked in the molten glass so that its end 14 is below the glass surface S and the tube moves in the fire resistant loop 13 over the waist 4 (the base is shown in FIG. 2). do. In FIG. 2 there is an atmospheric space between the molten glass surface S through which the tube 11 passes and the loop 13 which provides a sufficiently hot environment for melting additional material in the tube. Additional materials of suitable type, for example, tablets, when used, are fed into the panel 12 in a particular appropriately convenient manner and melt as it is moved under the tube 11 by gravity. Bottom end 14 of the tube (as indicated by the row of arrow heads) in the spring body of the molten base glass that flows (as indicated by the arrow) below the surface S and toward the stirrer 9. Protrude from (FIG. 1).

3 schematically shows another form of a feeder, which is a modified version of that shown in FIG. 2 with the same reference numerals indicating the same parts. The version 3 in the bottom of the tube 11 is different from the version in FIG. 2. In FIG. 3 the tube leads to a conical section 15 with a central hole guided into a vertical pipe 16 with an associated guide 17 in smooth form to guide additional material melted from the vertical passage in the horizontal passage. . The bottom ends 18 of the pipes 16 are spaced at short intervals above the molten glass surface S level to give a drop height less than three times the orifice diameter of the pipe, where the orifice diameter may range from 10 mm. The bottom end 19 of the guide 17 has a level of molten glass surface S. When it is moved down the tube 11 by gravity, the molten additional material is centered on the cone 15 into the pipe 16 for protruding from its bottom end 18 where it falls on the guide 17. Passed through the hole. The molten additional material is then gently guided onto the molten base glass surface S from the end 19 of the guide 17.

Bubble problems caused by introducing an additional material below the glass surface that is guided on the glass surface as shown in FIG. 3 or molten as shown in FIG. 2 (eg, the additional material is directly on the glass). Can be avoided or reduced).

4 schematically shows an additional form of a feeder that introduces additional material under the molten base glass surface. It comprises a vertical supply member in the form of a pipe 20 with a lower end 21 that is wetted below the glass surface. The outermost bottom end 22 of the pipe is in contact with the direction of movement of the molten glass stream (as indicated by the arrow) and on one side is an outlet extending in the vertical direction by a series of small holes 23 arranged in a vertical line. Have In the molten state of the pipe 20, additional material protrudes through the holes 23 (eg, may be about 1 mm in diameter) in the molten base glass. The holes are distributed vertically along the recessed end 21 of the pipe, so that additional material is distributed vertically to the molten glass over the entire depth and major part of the stream as it is added.

The upper part of the pipe 20 carries a diameter head 24 which rises above the hollow melting apparatus with the horizontal part 26 and the inclined part 25 positioned hot. Although other heating methods may be used, the hollow melting apparatus may be directly heated to conductive if desired. The pair of oblap baffles 27, 28 is arranged at its bottom, which is fed into the head 24 of the pipe 20, with a horizontal section 26 in the upper stream of the outlet pipe 29. The inclined portion 25 of the melting apparatus has an entry 30 which, when used, is provided for melting a tablet of additional material. The molten additional material may pass along the horizontal portion 26 to the baffles 27 and 28, which can only be passed by flowing under the upper baffle 27 and then over the lower baffle 28. By this arrangement, the lower edge of the upper baffle 27 is at a level lower than the upper edge of the lower baffle 28, the baffle being other to allow cleaning only the residue and the additional material melted to pass therebetween. Form filter devices for unwanted problems. The material then flows through the outlet pipe 29 and below the head 24 of the pipe 20 to protrude through the hole 23 in its lower portion 21 as described above.

The additional material melted with the above embodiment of the feeder is distributed vertically to the molten base glass as added to it, so that there is no need to provide additional vertical distribution, for example by a helical stirrer as described above. . Therefore, FIG. 4 shows one of a pair of paddle stirrers having a vertical axis 31 carrying a vertical paddle 32 protruding at its lower end. The axis 31 is rotated (as indicated by the arrow) and the recessed paddle 32 is horizontal to carry the deformation material to generate relative horizontal motion in the molten glass with the component transverse to the direction of travel of the stream. The flow melted base glass is stirred. This distributes the deformation material horizontally in the molten glass.

The feeder pipe 20 and the stirrer shaft 31 are suitably installed for passing through the loop 33 over the substantially horizontal channel along the molten glass stream, the base of which is indicated as 34 in FIG. 4 and flowing. do. The upper portion of the pipe 20 passing through the fire resistant loop structure 33 is electrically heated directly to confirm that the temperature is maintained as the liquid addition stream continues to flow. In addition, FIG. 4 shows an electrical heater 35 installed in the air space between the loop and the molten glass surface S on which the pipe 20 is heated to confirm the flow of additional liquid.

Multiple pipes 20 and multiple paddle stirrers may be spaced along and across the glass stream. The paddle stirrer is preferably located in the short spaced bottom stream from the pipe 20 so that it attracts the substantially vertical arrangement of the deformable material, for example to prevent depression and to attract molten glass carrying the deformable material thereon.

The described vertical lines of the holes 23 in the lower end portion 21 of the pipe 20 are given by way of example and other outlet arrangements are used. The outlet is not necessarily necessary in the direction of travel of the stream and, as another example, may be a series of holes in which the environment of the pipe being rotated is arranged to be bent. In addition, the pipes do not necessarily have to be vertical and can be wholly or partially inclined so that the outlet still extends into the vertical component. In particular, the recessed end 21 can be angled along the direction of travel of the stream so that its bottom end 22 is in the lower stream than its upper end. The straight pipe may be similarly angled if it can be vertical or banded in the region of the glass surface S to provide an inclined lower portion 21. Various other arrangements are possible, in particular to meet the required geometry. In addition, the deformable material need not be melted separately as shown by reference to FIG. 4 but may be melted in the tube 11 as shown by reference to FIG. 3. The short pipe 20 form of FIG. 4 can be connected to the bottom end of the tube 11 in FIG. 3 instead of the guide 17 and the pipe 16. If desired, the arrangement may be contacted to apply a reduced pressure or vacuum to the tube 11 to have a degassing effect on the material contained therein to reduce the risk of bubbles.

FIG. 5 is a view similar to FIG. 1, using the same reference numerals to designate the same parts. The arrangement of FIG. 5 has a paddle stirrer and a feeder as described with reference to FIG. 4 arranged at all of the working ends 5. For ease of explanation, FIG. 5 shows a single feeder 36 and a single pair of paddle stirrers 37 and in practice, a plurality of feeders, for example two or three feeders, may be used and each connected to each feeder. It may be a pair of paddle stirrers. Double with a plurality of feed pipes over the width of the molten glass stream, it is preferably spaced apart so that each feeder is cleanly connected to a particular pair of paddle stirrers.

The longitudinal spacing of the agitator 37 from the feeder 36 is typically less than the space between the agitator centers, which may range from 300 mm to 1.3 m, for example about 600 mm. Typically the temperature of the molten glass at the location of the stirrer 37 may range from 1100 ° C. to 1400 ° C., for example about 1180 ° C.

An additional paddle stirrer corresponding to stirrer 10 in FIG. 1 may be present in the FIG. 5 embodiment towards the upper stream end of conduit 6. If desired, paddle stirrer 38 may be provided towards the bottom stream of conduit 6 in both FIGS. 1 and 5 embodiments to effect the horizontal distribution of additional deformable material.

1 and 5 generally show the outlet 7. A stream of molten glass with substantially homogeneously distributed strain material is delivered from the outlet to the forming facility. FIG. 6 schematically shows a float glass forming installation having a float bath 39 delivered from a spout 40 with a control twill 41 in which molten glass is coupled. For this installation the delivered molten glass with the deformable material connected to the outlet 40 of FIG. 1 and 5 distributed substantially homogeneously thereon is connected in the float glass in a well known manner. Is formed. Bubble problems can be avoided or reduced by first limiting the molten glass and then adding and distributing the modifying material in a manner as described. Multiple values of temperature and dimensions are given by all relevant examples above in glass melting furnaces or tanks for float glass forming equipment.

Although interested in the high quality requirements for float glass, in particular the invention is used for float glass and can be applied to other forms of rigid glass such as wound plates or extracted sheets. The invention can also be applied to other forms of glass articles for container products or television tubes. In each case, the outlet from the glass melting furnace or tank is connected with a suitable forming facility.

As indicated above, the modifying material may be a colorant material. The base glass to which the colorant is added is a clean glass so that the colorant is lightly deformed. In the latter case, the modified pale cullets are recyclable in the melting tank for the base pale. However, other property variations may be used than the collar (eg refractive index).

Substantial changes in hue (or other traits) over the areas of hard glass and double a glass normally observed through the thickness of the glass can be rapidly recognized, but changes through the thickness are generally less relevant. Therefore, even distribution of the deformable material over the area of the glass is more important than even distribution through its thickness and the reference is made to distribute substantially homogeneously to the rigid glass.

It will be appreciated that the accompanying drawings, in particular Figures 1 and 5, are schematic drawings and not actual accumulation. The method of the invention can be used with various glass melting tanks or furnaces and FIGS. 1 and 5 are schematically illustrated as one for the purpose of explanation. Therefore, although not necessary, the substantially horizontal channel (provided by the elements 4, 5, 6 in FIGS. 1, 5) has a width and / or depth change along its length, the change being stepped Rather gradual. In addition, the unidirectional flow of the molten glass stream begins in the upper stream of additional deformable material (eg, the restricted area 3 of FIGS. 1, 5).

Modifications from the specific embodiments described to be made without departing from the principles of the invention are apparent to those skilled in the art. For example, although it is desirable to be affected by the vertical distribution of the deformable material in the molten glass before being affected by the horizontal distribution, the horizontal distribution may be an environment that can be usefully affected before the vertical distribution. Deformation material distribution in the molten glass can be affected by other means than specifically described. Therefore, in particular the vertical distribution can be mechanically agitated or can be generated by conventional current produced by a mechanical stirrer rather than by a heater such as an electrode or can be a combination of an electrode and a stirrer. In addition, in the described embodiment a glass melting furnace or tank is indicated when providing a unitary body, and one tank may provide a plurality of outlets connected with a plurality of forming facilities. If desired, glass deformation may occur in the channel between the melting furnace or tank and each forming facility such that another facility or line produces another product as disclosed, for example, in British Patent No. 9616364.7.

Claims (17)

In which the molten base glass flows unidirectionally in a stream form along a horizontal channel, and adding the modifying material to the horizontally flowing molten base glass. In Vertically dispensing the strain material in the molten glass, horizontally dispensing the strain material in the molten glass having a dispensing component transverse to the direction of travel of the stream, and having a homogeneously distributed strain material. Transferring the stream of molten glass to a molding facility. 2. The method of claim 1, wherein the strained material is added to the molten base glass and then separated and distributed vertically to the molten glass. 3. The base glass variant according to claim 2, wherein the modifying material is distributed vertically in the molten glass by agitating a horizontally flowing molten base glass with the modifying material for relative vertical motion in the molten glass. Way. 4. The molten base glass according to any one of claims 1 to 3, wherein the deformable material is flowed horizontally with the deformable material to generate a relative horizontal motion in the molten glass having a component transverse to the direction of movement of the stream. The base glass transformation method, characterized in that the horizontal distribution in the molten glass by stirring. 5. Method according to claim 3 or 4, characterized in that the agitation is carried out before the separate agitation produces a relative horizontal motion in order to generate a relative vertical motion. 6. The method of claim 1, wherein the additive is in molten form when added to the molten base glass. 7. 7. The method of claim 6, wherein the molten additive is slid onto the surface of the molten base glass. 7. The method of claim 6, wherein the molten additive is added below the surface of the molten base glass. 9. A method as claimed in claim 8, wherein the additive is added in such a way that when added it is distributed vertically to the molten glass. 10. The method according to any one of claims 1 to 9, wherein the forming facility is flat glass, any float glass, and forming molten glass with a homogeneously distributed strain material in the flat glass, any float glass. Base glass deformation method comprising a. Flat glass, any float glass made by the method according to claim 10. In a strain material adding apparatus for adding strain material to a horizontally flowing stream of molten base glass (4, 5, 6), Supply members 8, 11, 20 having lower portions 14, 21 for recessing in the molten glass and outlets 18, 19 of the deformable material, and into the molten glass stream below its surface S; Means for feeding the deformable material into the feed member for protruding therethrough, the outlet extending with a vertical component to distribute the deformable material beyond at least a major portion of the stream depth. 13. Apparatus according to claim 12, characterized in that the outlet (18, 19) is on one side of the supply member (20, 21, 22) that is in use in the direction of movement of the stream (S). 14. Apparatus according to claim 12 or 13, characterized in that the outlet comprises a series of holes (23). 15. Apparatus according to claim 12, characterized in that the melting apparatus (25, 26) melts the deforming material and delivers it to the supply member in a molten state. 16. Apparatus according to claim 15, characterized in that the melting device (25, 26) comprises a filter device (28) which prevents the transfer of non-desired substances to the supply member. 17. Apparatus according to claim 12, characterized in that the supply member is a pipe (11, 16, 20).