RU2623404C1 - Method of manufacturing crucible with quartz ceramic bottom branch pipe and device for its implementation - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: crucible preforms with a bottom hole are made separately from the branch pipe. In gypsum molds, inserts are installed with a gap equal to the wall thickness of the future crucible preform or the branch pipe. In the gaps, a slurry of quartz glass grits is poured. The preforms of the crucible and the branch pipe are formed. The inserts are removed, and the preforms are dried in gypsum molds in the air for, at least, 48 hours. The gypsum molds are removed. Assembly of the crucible preforms and the branch pipe is made into one product. The branch pipe is fixed in a tripod, onto which the support ring is mounted. Above, the crucible is fed in such a way that part of the branch pipe above the support ring protrudes at a small distance above the inner wall of the crucible. Between the gaps formed between the parts of the outer wall of the branch pipe and the bottom of the crucible, which are attached to fixing, a slurry is poured. Drying in the open air is not less than 72 hours. Then it is fired at a stepwise rise in temperature from 20 to 1200°C with an exposure of up to 2 hours at each temperature range, with a temperature rise rate of 50°C/hour up to 150°C/hour.

EFFECT: obtaining a crucible with a quartz ceramic bottom branch pipe with a uniform wall thickness.

2 cl, 5 dwg

Description

The group of inventions relates to the technology for the production of complex-shaped large-sized products from quartz ceramics with a volume of up to 60 liters for glass melting, in particular to the manufacture of crucibles with a bottom nozzle from quartz ceramics.

The prior art known crucible with a bottom hole of quartz for glass melting (patent JPH0397629, IPC C03B 5/08; C03B 5/26, publ. 04/23/1991). A platinum pipe is inserted into the bottom opening of the crucible and fixed with a flange from the outside. When cooking glass, the platinum pipe is cooled by water or gas. The disadvantages of the known crucible include the use of expensive platinum pipe, the need for its cooling during glass melting, as well as the complexity of assembling structural elements.

In Chinese Patent No.201062229, publ. 05/21/2008, according to the IPC index С03В 5/08, a rectangular crucible with a bottom pipe made of quartz ceramics is declared, with a platinum pipe inserted, and water cooling is connected at the junction of the platinum pipe and the bottom pipe. The disadvantages of the analogue include the need to assemble the elements in one design, the use of an expensive platinum pipe, the need to create a cooling system for the platinum pipe during glass melting, and the irrational form of the crucible that does not drain the entire volume of glass mass through the bottom pipe during cooking.

To obtain a crucible with a given geometry of the inner part and a uniform wall thickness, only a gypsum core was used. Disadvantages of gypsum core:

1 / if the core is "active", i.e. the formation of the crock occurs on the surface of the mold and the formation of shells (cavities) between the two layers of the crock is possible on the surface of the core. In addition, the active surface of the core contributes to the creation of strong stresses in the crock when removing the core from the mold;

2 / an inactive (i.e. not forming a shard) core made of gypsum is very difficult to remove without damaging the inside of the crucible. In addition, defects are often formed in the form of shells (air bubbles) due to the low wettability of the gypsum surface of the core.

To eliminate these drawbacks, an invention is proposed, which is a group of objects united by a single inventive concept: a method for manufacturing a crucible of complex configuration with a bottom nozzle made of quartz ceramic and a device for its implementation.

EFFECT: obtaining a crucible with a bottom nozzle made of quartz ceramic with uniform wall thickness, which is a single integral product, the length and diameter of the outlet for which can be changed in accordance with the requirements of the process of surfacing and the release of glass melt.

A method of manufacturing a crucible of complex configuration with a bottom nozzle made of quartz ceramics consists in the sequential manufacture of a crucible with a bottom hole and a nozzle, followed by combining them into one product.

A method of manufacturing a crucible with a quartz ceramic bottom nozzle, comprising separately manufacturing blanks for a crucible with a bottom hole and a nozzle and then connecting the resulting blanks to one product, using gypsum molds with a gap equal to the wall thickness of the future crucible blank or nozzle, inserts made of inert material are installed, and corresponding to the shapes of the crucible and nozzle blanks, a slip made of quartz glass grains containing SiO is poured into the formed gaps ₂ not less than 96 mass. %, thus forming raw crucible products with a bottom hole and pipe, remove the liners and dry the raw products in gypsum molds in air for at least 48 hours, then remove the gypsum molds, and from the obtained billets of the crucible with a bottom hole and pipe carry out their assembly into one product by fixing the nozzle in a tripod, on which the support ring is mounted, then the crucible is brought in from above so that the part of the nozzle above the support ring protrudes a short distance above the inner wall of the crucible, and In the process of filling the slurry, fill the slip between the voids formed between the parts of the outer wall of the nozzle and the inner wall of the crucible with the bottom hole that are mated for fastening, and the resulting form of the crucible with the bottom nozzle is dried in air for at least 72 hours, then calcined with a stepwise increase in temperature from 20 to 1200 ° С with an exposure of up to 2 hours at each temperature interval, at a rate of temperature rise from 50 ° C / hour to 150 ° C / hour, after which it is inertially cooled.

A device for the manufacture of a crucible with a bottom hole containing a gypsum mold having a gypsum base with a bottom hole located in the center, on which a gypsum body made in the form of a hollow cylinder is mounted, an inert material insert consisting of a rigid bowl-shaped core is inserted into the gypsum mold, on which a flexible shell is put on, repeating the shape of the core, the bottom of which is made outside with a base protruding outward, the diameter of which corresponds to the technological interface with the pipe, and there is a central hole, while the core with the sheath on it is rigidly fixed using a metal anchor inserted vertically in the central part of the core and provided with a metal eye with a ring protruding from above, as well as a fixing bolt from the outside from the bottom of the gypsum base, while on top of the gypsum a centering ring equipped with slotted holes is fitted.

A crucible with a bottom pipe and a pipe are made of quartz ceramic. The feedstock for ceramics is a quartz glass slurry. Ceramics contains SiO ₂ not less than 96 mass. % A crucible with a bottom nozzle is made by slip casting in bulk.

The group of inventions is illustrated by drawings:

- in FIG. 1 schematically shows a device for producing a crucible with a bottom hole in an assembled form with a vertical section, where 1 is a core made of polyurethane foam, 2 is a core shell made of silicone, 3 is a centering ring made of polyurethane foam, 4 is a gypsum-shaped body 5 - the base of the plaster mold, 6 - the mounting bolt, 7 - metal anchor, 8 - metal eye. Between the inner wall of the gypsum mold and the shell of the core 2, a gap is formed corresponding to the calculated value of the thickness of the crucible;

- in FIG. 2 shows a top view of a device for producing a crucible with a bottom hole, where 9 are slotted holes on the centering ring 3;

- in FIG. 3 schematically shows a device for producing a bottom pipe, where 10 is a liner-core made of silicone in the form of a truncated cone, 11 is a supporting gypsum ring, 12 is a gypsum-shaped body, the inner surface of which is made in the form of a truncated cone, 13 is a gypsum-shaped base , 14 - a metal rod with a screwed nut;

- in FIG. 4 shows a top view of a device for producing a bottom pipe, where 15 are the resulting gaps between the support ring 11 and the core insert 10;

- in FIG. 5 is a schematic cross-sectional view of a crucible 16 with a bottom nozzle 17, the resulting ceramic layer 18 in the process of connecting the nozzle 17 and the crucible 16 with the bottom hole.

The implementation of the invention.

First make a crucible with a bottom hole using a device for its manufacture. A device for making a crucible with a bottom hole is assembled as follows (see Fig. 1):

1. The base of the gypsum mold 5 is mounted on a wooden pallet (not shown in the drawing).

2. On the base 5 of the gypsum mold, the body of the gypsum mold 4 is installed (fixation due to the thorn-groove connection).

3. On the upper edge of the body of the gypsum mold 4 set the centering ring 3.

4. Then on the core 1 put on the shell 2 of the core, after which the core 1 with the shell 2 on it is lowered into a plaster mold.

5. Using the fixing bolt 6, the core 1 is rigidly fixed on the base of the gypsum mold 5 from the outside.

6. Then, in the places of the slit holes 9 of the centering ring 3 (see Fig. 2), plastic glasses (not shown) are installed and the slip is filled through them (quartz glass suspension). The number of slotted openings - runners is advisable in the amount of four. The slip is poured simultaneously into two slotted holes 9 located opposite each other to form a uniform wall thickness of the crucible.

As the level of the slip in the filling gap decreases as a result of the absorption of the aqueous component into the gypsum mold, it is simultaneously replenished in all four holes. A probe in the form of a metal rod determines the height of the crock set, lowering it into each slot hole 9.

7. Upon reaching the required level of the crock, remove the plastic glasses, remove the remaining slip in them with a rubber bulb. Unscrew the mounting bolt 6, install on the surface of the centering ring 3 a removable device (U-shaped) (not shown), with which the hard core 1 is removed, while the core shell 2 remains in gypsum form.

The removable device is fixed with an anchor 7 to the eye 8, due to the rotation of which the rigid core 1 rises. Then the silicone shell 2 is removed. After cleaning the slit holes 9 from the residues of the slip, the centering ring 3 is removed. The obtained crucible product is dried in air in gypsum form 4 for ~ 48 hours, obtaining the crucible blank.

8. After drying, the base of the gypsum mold 5 is removed, and the gypsum body 4 with the crucible blank is suspended on the hoist. Then, using the rotary device from the gypsum body 4 take out the crucible.

9. Similarly, a nozzle is made using a gypsum mold in which the core insert 10 is made of an inert material, for example, silicone. The gypsum mold consists of a gypsum support ring 11, a housing 12 and a base 13. A pipe billet is obtained by simultaneously filling a slip in the gaps 15 of the support ring 11 and between the core 10 and the gypsum mold. The metal rod 14 inside the core of the liner 10 is necessary for the convenience of removing the core of the liner 10 from the plaster mold after dialing the shard of the bottom pipe.

To give the pipe an external shape, which has a bend in the zone of connection with the bottom hole of the crucible, it is additionally processed manually in a dry form before assembly with the crucible blank.

10. After drying, the pipe 17 is connected to the crucible 16 in the region of the bottom hole in one product as follows: the pipe 17 is fixed in a tripod, then a support ring is installed on it (not shown in the drawing), after which the crucible 16 is brought in from above so that the part of the pipe above the support ring protruded a small distance above the inner wall of the crucible; finally, a slip is poured between the voids 18 formed between the outer walls of the pipe 17 and the walls of the bottom hole of the crucible 16. The resulting billet I with bottom nozzle air dried for at least 72 hours. Then, the dried product is fired at a stepwise temperature increase from 20 to 1200 ° C with exposure at each temperature range up to 2 hours at each temperature interval, at a temperature rise rate from 50 ° C / hour to 150 ° C / hour, after which inertia cool.

The claimed group of inventions forms a single inventive concept: a method of manufacturing a crucible with a bottom pipe made of quartz ceramic and a device for its implementation. A crucible with a bottom nozzle made of quartz ceramic is a single integral product with walls of uniform thickness. Depending on the technological parameters of the process of surfacing and the release of glass melt, the length and diameter of the outlet of the nozzle can be varied. In addition, it is possible to repeatedly use the device to obtain a crucible with a bottom hole for the production of such crucibles, as well as the use of structural elements of the device made of accessible and inexpensive materials, which will significantly reduce the cost of manufacturing crucibles with a bottom pipe.

Claims (2)

1. A method of manufacturing a crucible with a bottom nozzle made of quartz ceramic, comprising separately manufacturing blanks for a crucible with a bottom hole and a nozzle and then connecting the resulting blanks to one product, using gypsum molds with a gap equal to the future wall thickness billets of the crucible or pipe, install liners made of inert material, and corresponding to the shapes of the billets of the crucible and pipe, in the formed gaps fill slip from the grains of quartz glass with the content of S iO ₂ not less than 96 mass. %, thus forming raw crucible products with a bottom hole and pipe, remove the liners and dry the raw products in gypsum molds in air for at least 48 hours, then remove the gypsum molds, and from the obtained billets of the crucible with a bottom hole and pipe carry out their assembly into one product by fixing the nozzle in a tripod, on which the support ring is mounted, then the crucible is brought in from above so that the part of the nozzle above the support ring protrudes a short distance above the inner wall of the crucible, and In the process of filling the slip between the voids formed between the mating parts for fixing the outer wall of the nozzle and the bottom of the crucible with the bottom hole, the resulting form of the crucible with the bottom pipe is dried in air for at least 72 hours, then subjected to calcination with a stepwise increase in temperature from 20 to 1200 ° C with an exposure of up to 2 hours at each temperature interval, at a rate of temperature rise from 50 ° C / hour to 150 ° C / hour, after which it is inertially cooled. 2. A device for the manufacture of a crucible with a bottom hole, containing a gypsum mold having a gypsum base with a bottom hole located in the center, on which a gypsum body made in the form of a hollow cylinder is mounted, an inert material insert made of a rigid cup-shaped material is inserted into the gypsum mold core, on which a flexible shell is put on, repeating the shape of the core, the bottom of which is externally made with a base and a central hole, while the core with the shell on it is rigidly fixed with with the help of a metal anchor inserted vertically in the central part of the core and equipped with a metal eye with a ring protruding from above, as well as a fixing bolt outside the bottom of the gypsum base, and a centering ring equipped with slotted holes is put on top of the gypsum mold.

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