Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B19/00—Other methods of shaping glass
  • C03B19/14—Other methods of shaping glass by gas- or vapour- phase reaction processes
  • C03B19/1484—Means for supporting, rotating or translating the article being formed
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
  • C03B37/01—Manufacture of glass fibres or filaments
  • C03B37/012—Manufacture of preforms for drawing fibres or filaments
  • C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
  • C03B37/01486—Means for supporting, rotating or translating the preforms being formed, e.g. lathes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P40/00—Technologies relating to the processing of minerals
  • Y02P40/50—Glass production, e.g. reusing waste heat during processing or shaping
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P40/00—Technologies relating to the processing of minerals
  • Y02P40/50—Glass production, e.g. reusing waste heat during processing or shaping
  • Y02P40/57—Improving the yield, e-g- reduction of reject rates

Definitions

• the invention relates to a device for producing a quartz glass body, with an elongated mandrel, which is rotatably mounted about its horizontally oriented longitudinal axis of the mandrel, with at least one deposition burner, by means of which SiO 2 particles are deposited in layers on the outer surface of the dome to form a porous blank with a first holder which surrounds the mandrel in the form of a sleeve in the region of one of the ends of the forming blank and is partially embedded in the forming blank, and with at least one fixing element by means of which the dome and the first holder are rigidly connected to one another.
• the invention relates to a method for producing a quartz glass body by layer-by-layer deposition of SiO 2 particles on the outer surface of an elongated dome rotating about its horizontally oriented longitudinal axis of the dome, forming a porous blank, the mandrel rotating at the same rotational speed first holder, which surrounds the mandrel in the region of one of the ends of the forming blank and is at least partially embedded therein, is rigidly connected, removing the dome and sintering the blank thus produced.
• Quartz glass tubes are used as components and as intermediate products in the chemical industry, semiconductor production, in the field of optics and in particular for the production of preforms for optical fibers.
• a method and a device for producing a tube made of synthetic quartz glass according to the type mentioned at the outset are known from US Pat. No. 4,362,545.
• SiO 2 particles are deposited in layers by means of a flame hydrolysis burner on the cylinder jacket surface of a slightly conical dome, which is clamped at both ends in a lathe and rotates about its longitudinal axis.
• a reciprocating movement along the longitudinal axis of the dome forms a hollow cylindrical, porous blank made of SiO 2 particles.
• the mandrel extends through a sleeve-shaped holder, which has a circumferential bead at its end, which faces the blank being formed.
• the mandrel is geometrically fixed with respect to the holder by means of spacers which are clamped in the gap between the holder and the mandrel.
• the part of the holder provided with the bead is embedded in the blank being formed.
• the cathedral is removed.
• the blank can be held hanging on the embedded holder in a vertical orientation.
• the desired quartz glass body is then obtained by sintering and collapsing.
• the holder and dome are made of graphite or quartz glass, for example. Because of its mechanical and chemical stability, aluminum oxide (Al 2 Q_) is preferably used as the material for the mandrel. In order to facilitate the removal of the dome, it can be slightly conical, as is also mentioned in US Pat. No. 4,362,545. Such conical domes are made by grinding. This requires a lot of work - especially with long domes. The manufacture of cylindrical mandrels is easier, so cylindrical domes would therefore be preferable. However, their removal, particularly in the case of long blanks, is problematic and requires high forces which can easily lead to damage to the blank. Regardless of this, the length of a dome increases the risk that it will break due to angular or dimensional deviations during clamping or during use.
• JP 4-240126 interpreted by the associated PAJ abstract, shows a further device for producing a tube made of synthetic quartz glass by a so-called OVD process.
• SiO 2 particles are deposited in layers on a rotating mandrel within a reaction chamber.
• the dome ends are received in rotatable holder elements, which are located opposite each other within the reaction chamber.
• the mandrel extends beyond the length of the pipe to be manufactured.
• the present invention has for its object to provide an operationally reliable method for the production of tubes made of quartz glass and a suitable device To provide, which can be produced in comparison to the known device with less manufacturing effort and in which the risk of breakage of the mandrel is reduced.
• this object is achieved according to the invention, starting from the device mentioned at the outset, in that a first end-side end of the dome ends in an inner bore of the first holder, and in that a first bearing element is provided by means of which the first holder is rotatably mounted.
• the dome does not extend through the entire inner bore of a sleeve-shaped holder, as in the known device, but a first end-side end of the dome ends in an inner bore of the first holder.
• at least one fixing element is provided, the inner bore itself serving as a fixing element or such a one being able to be provided in or on the inner bore or on the holder.
• a first bearing element is provided which can engage either directly on the holder or on a component rigidly connected to the holder.
• the mandrel itself can be made correspondingly shorter. Accordingly, the material costs for the mandrel are lower and in particular the manufacturing effort is lower. In addition, handling the shorter dome - such as assembly and disassembly - is easier and the requirements for dimensional accuracy and alignment of the mandrel are lower. In addition, the deflection of the shorter dome is significantly less, which in turn is accompanied by a more precise centering and an improvement in the axisymmetric concentricity of the dome.
• the teaching according to the invention thus comprises the measure according to which the mandrel is shortened to such an extent that it ends within the blank being formed. Since the first holder is at least partially embedded in the blank being formed, the holder can be used as a handle for holding during the subsequent further processing of the blank.
• the mandrel can be designed as a rod or a tube, with a cylindrical outer surface or conical. It is not necessary for the inner bore of the first holder to completely radially surround the first end of the mandrel.
• An inner bore which runs coaxially to the longitudinal axis of the dome, is particularly simple, the inner diameter of which is adapted to the outer diameter of the mandrel, and which is designed with a taper against which the end of the dome rests.
• the inner bore encloses the end of the mandrel, the diameter of the inner bore being matched to the outer diameter of the dome with as little mechanical play as possible. It is essential that the inner bore has a taper against which the end of the dome rests. For example, in the event that the end of the dome has a flattened or tapered area, the taper of the inner bore can be adapted accordingly.
• the taper is designed in the form of a constriction of the inner bore.
• a constriction is particularly easy to produce with a quartz glass holder.
• the holder is softened by heating and the inner bore in the area of the constriction is narrowed by plastic deformation.
• the inner bore has a diameter which is smaller than the largest outer diameter of the mandrel in the region of its end on the face side, so that the constriction serves as an abutment for the mandrel resting thereon.
• the end of the cathedral can taper towards the constriction.
• the taper is designed in the form of an insert part fixed in the inner bore.
• the inner bore is narrowed by the insert.
• the insert can be designed, for example, as a disc, ring or tube. It serves as an abutment for the mandrel resting on it.
• the insert is fixed in the inner bore to prevent it from slipping out of the inner bore.
• the fixation can be done by mechanical clamping and holding elements, such as screws, pins or clamps, or by a form-fitting geometric design of the insert and inner bore, for example as an inner cone and cone.
• the inner bore is designed as a through bore
• the insert part is provided with a center bore, wherein it projects into the through bore from the side opposite the mandrel and ends therein.
• the insert can for example be designed as a ring or tube.
• the center hole can be a hole with an opening in the direction of the first end-side dome end or a through hole running in the dome longitudinal axis direction.
• the inner bore is narrowed through the center bore of the insert.
• the center hole has an inside diameter that is smaller than the largest outside diameter of the mandrel in the region of its end on the face side, so that the insert part serves as an abutment for the mandrel resting on the center hole.
• a further improvement is obtained if the mandrel tapers in the direction of its first end in a tapering area, the tapering area on the front lying against the insert part.
• the dome can taper conically in the tapered area, for example, or it can have one or more obliquely extending flats.
• Self-centering and axial alignment of the mandrel and holder can be achieved if an axially symmetrical (essentially conical) tapering area rests against the end edge of the inner tube.
• the outer diameter of the end of the insert part projecting into the inner bore is smaller by a gap than the inner diameter of the inner bore, the end projecting into the inner bore through at least one longitudinal slot, preferably at least two longitudinal slots can be elastically deformed in such a way that the outer diameter can be increased by at least twice the gap width in the event of a force acting radially from the inside out.
• the at least one longitudinal slot runs only over a partial length of the insert.
• the end projecting into the inner bore is divided into two separate half-shells, which, however, are still connected to the remaining insert part by two longitudinal slots which run parallel on opposite sides.
• the half-shells can be spread apart by a force acting radially from the inside out. The maximum spread depends, among other things, on the force, the length of the longitudinal slots, the modulus of elasticity of the insert material and its wall thickness. According to the invention, it is set so that the free the ends of the half-shells on the inner wall of the through hole.
• the half-shells encompass the tapered area of the dome, which, due to its wedge effect on the half-shells, generates the force directed radially from the inside out. This ensures a central and play-free mounting of the mandrel in the center hole of the insert and in the inner hole of the holder.
• a clamping element acting on the dome is advantageously provided, by means of which a thrust force acting axially in the direction of the first end-side end is exerted on the mandrel.
• the pushing force helps to fix the mandrel in or on the first holder.
• the dome can be pressed against an abutment by the thrust.
• the thrust force acting in the axial direction via the tapering region of the mandrel within the center bore of the insert part provides a force component directed radially from the inside out, by means of which the longitudinally slotted insert part can be expanded against the inner wall of the inner bore.
• a further shortening of the dome is made possible when the second front end of the dome ends in a receptacle of a second holder and a second bearing element is provided, by means of which the second holder is rotatably mounted.
• the dome is held horizontally between the two holders and stored in it.
• One of the holders or both holders can be embedded in the blank being formed during the deposition.
• the clamping element mentioned above is arranged in the receptacle of the second holder, acting on the second end of the dome.
• the holder of the second holder serves both for mounting the second dome end and for receiving the tensioning element.
• the clamping element can be, for example, a compression spring resting on the second end of the mandrel.
• the first holder consists of quartz glass and is embedded in the blank being formed over a length of at least 40 mm, preferably at least 60 mm.
• the fact that the holder is made of quartz glass largely prevents contamination of the blank.
• the holder is used in the subsequent process steps for handling the blank, such as for hanging in an oven. By partially embedding the holder over a length in the range from 40 mm to 100 mm or more, a stable mechanical connection between the blank and the holder is achieved.
• the above-mentioned object is achieved according to the invention based on the method mentioned at the outset by using a dome, of which an end at the end ends in an inner bore of the first holder, and by mounting and rotating the first holder by means of a first bearing element ,
• a dome which ends in an inner bore of the first holder.
• the holder and mandrel are rigidly connected to each other.
• the holder thus serves as a mechanical extension of the mandrel.
• the holder is in turn arranged so close to the front end of the blank that is formed that it is embedded therein during separation.
• the inner bore of the holder itself can be used, for example, for fixing, or a suitable fixing means can be provided in or on the inner bore or on the holder. It is essential that the end of the mandrel ends in the inner bore and that the mandrel is held, supported and rotated by means of the holder. It is therefore necessary that the holder itself is stored and rotated during the deposition.
• a first bearing element is used, which engages either directly on the holder or on a component rigidly connected to the holder.
• the teaching according to the invention thus comprises the measure according to which the mandrel is shortened to such an extent that it ends within the blank being formed.
• the holder which is at least partially embedded in the blank can be used as a handle for the holder in the subsequent further processing of the blank.
• a shorter dome is used in comparison to the known method. Accordingly, the material costs and the manufacturing costs for the production of the mandrel are lower. In addition, the handling of the shorter dome - such as assembly and disassembly - is easier and the requirements for dimensional accuracy and alignment of the dome are lower, which has a favorable effect on the operational reliability of the method. In addition, the deflection of the shorter dome is less, which in turn is accompanied by an improvement in the centering and the axisymmetric concentricity of the dome.
• FIG. 1 shows a first embodiment of the device according to the invention for producing a quartz glass tube in a side view
• Figure 2 shows a further embodiment of the device according to the invention in one
• FIG. 3 shows an enlarged detail of the device according to FIG. 2.
• the reference number 1 is assigned to a horizontally oriented aluminum oxide construction tube.
• the right end 2 of the assembly tube 1 in the illustration is mounted in the chuck 3 of a glass lathe (not shown in FIG. 1) rotatable about its longitudinal axis 4.
• the direction of rotation is indicated by the arrow 5.
• the left end 6 of the body tube 1 extends into the inner bore 7 of a sheath-shaped holder 8 made of quartz glass.
• the holder 8 is provided with a circumferential constriction 9, which locally narrows the inner bore 7.
• the inner bore 7 has a diameter of 8 mm, which corresponds approximately to the outer diameter of the body tube 1.
• the diameter of the inner bore 7 is smaller by approximately 1 mm, so that the constriction 9 forms an abutment against which the end 6 of the mounting tube 1 rests on the end face.
• the holder 8 is rotatably mounted in the other chuck 10 of the glass lathe.
• the body tube 1 is fixed and aligned in the inner bore 7 of the holder 8 with as little play as possible.
• the holder 8 thus forms an extension of the body tube 1 and at the same time a bearing therefor. It is therefore not necessary for the mounting tube 1 to extend to the clamping jaws 10 of the glass lathe, so that it can be made shorter accordingly. In the exemplary embodiment, this results in a shortening of the body tube 1 by approximately 20%.
• the build-up pipe 1 rotating around its longitudinal axis 4 is deposited in layers of SiO 2 particles.
• a porous cylinder 13 is formed in which the front part of the holder 8 is embedded over a length of 60 mm.
• the holder 8 is rotated during the deposition by means of the other chuck 10 of the glass lathe, the assembly tube 1 being simultaneously fixed and aligned in the inner bore 7 of the holder 8 with as little play as possible.
• the mounting tube 1 is mechanically extended and stored by means of the holder 8. This procedure enables the use of a body tube 1, the length of which is not significantly longer or can even be shorter than that of the cylinder 13 to be produced. This simplifies the manufacture of the body tube 1 and facilitates its assembly.
• the cylinder 13 thus produced can weigh more than 10 kg. For its further processing, it can be handled by means of the embedded sleeve-shaped holder 8.
• a quartz glass tube is produced from the porous cylinder 13 by sintering.
• a horizontally oriented mounting tube 21 with an outer diameter of 8 mm is provided.
• SiO 2 particles are deposited in layers on the assembly tube 21 by means of a row 38 of flame hydrolysis burners 22, a porous hollow cylinder 23 being formed.
• the length of the mounting tube 21 is approximately 1.8 m, that of the hollow cylinder 23 is approximately 2 m.
• the left end 24 of the construction tube 21 in the illustration according to FIG. 2 extends approximately 30 cm into the inner bore 28 of a quartz glass sleeve 26.
• the inner bore 28 thereof has a diameter of 8.2 mm, which also roughly corresponds to the maximum outer diameter of the construction tube 21 equivalent.
• the left end 24 of the mounting tube 21 tapers in an end cone 29.
• An aluminum oxide tube 30 extends into the inner bore 28 from the side of the quartz glass sleeve 26 opposite the mounting tube 21.
• the outer diameter of the aluminum oxide tube 30 is 7.8 mm, so that between the inner bore 28 and the aluminum oxide tube 30 there is an annular gap with a gap width of 0. 2 mm remains.
• the front end of the aluminum oxide tube 30 is provided over a length of approximately 150 mm with two laterally opposed longitudinal slots 31, so that the front end of the aluminum oxide tube 30 has an upper half-shell 32 and a lower half-shell 33, which still with the remaining aluminum oxide tube 30 are connected, and which comprise the end cone 29 of the mounting tube 21.
• the aluminum oxide tube 30 slipping out of the interior bore 28 is prevented by a cross pin 34.
• the quartz glass sleeve 26 is rotatably mounted in the chuck 35 of a glass lathe (otherwise not shown in FIG. 2).
• the right-hand end 25 of the assembly tube 21 is supported in a receptacle in an Al 2 O 3 sleeve 27.
• a compression spring is provided in the receptacle, which axially loads the mounting tube 21.
• the Al 2 0 3 sleeve 27 is rotatably mounted in the other chuck 37 of the glass lathe.
• the fixation of the assembly tube 21 in the sleeve 26 becomes clearer.
• the left end 24 of the mounting tube 21 extends into the inner bore 28 of the quartz glass sleeve 26.
• the left end 24 of the mounting tube 21 tapers in an end cone 29, which in the half-shells 32; 33 of the longitudinally slotted aluminum oxide tube 30 protrudes. Due to the wedge effect of the end cone 29, the half-shells 32; 33 spread so far apart that they rest in the area 41 of the inner bore 28 of the quartz glass sleeve 26. This wedge effect is generated by a force which acts on the body tube 21 in the direction 43 of the longitudinal axis 40.
• SiO 2 particles are deposited in layers on the assembly tube 21 rotating about its longitudinal axis 40.
• the porous hollow cylinder 23 is formed, in which the front part of the holder 26 is embedded over a length of approximately 90 mm. This is achieved by inserting the end cone 29 into the inner bore 28 and pressing it under slight pressure against the slotted end (the half-shells 32, 33) of the aluminum oxide tube 30, so that the shark shafts 32, 33 are under the wedge action of the end cone 29 spread out and lay down in the area 41 against the inner wall of the inner bore 28.
• the force that presses the end cone 29 against the half-shells 32, 33 is generated by the compression spring 36.
• the body tube 21 is thus supported on both sides in sleeves 26, 27, in which it also ends.
• This method variant allows the use of a particularly short body tube 21, the length of which can be shorter than that of the hollow cylinder 23 to be produced. This simplifies the manufacture of the body tube 21, facilitates its assembly and improves its axial concentricity.
• a quartz glass rod or a quartz glass tube is obtained from the hollow cylinder by sintering.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Manufacture, Treatment Of Glass Fibers (AREA)
• Glass Melting And Manufacturing (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=7927516

Family Applications (1)

Country Status (6)

Families Citing this family (8)

Family Cites Families (6)

• 1999
  • 1999-10-29 DE DE19952474A patent/DE19952474C1/de not_active Expired - Fee Related
• 2000
  • 2000-10-26 EP EP00983093A patent/EP1140714A1/de not_active Withdrawn
  • 2000-10-26 CN CN00802444A patent/CN1342133A/zh active Pending
  • 2000-10-26 WO PCT/EP2000/010574 patent/WO2001032573A1/de not_active Application Discontinuation
  • 2000-10-27 KR KR1020000063461A patent/KR20010051283A/ko not_active Application Discontinuation
  • 2000-10-30 JP JP2000330996A patent/JP2001172025A/ja not_active Withdrawn

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events