SU852801A1 - Crucible for producing calibrated quartz tubes - Google Patents

Description

The aim of the invention is to improve the quality of pipes by eliminating the destruction of the nozzle.

The goal is achieved by the fact that the ratio of the angle of inclination of the working surface of the dune and the angle of inclination of the working surface is molded, its punch is within 2 bars.

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FIG. 1 shows a longitudinal section of a crucible; in fig. 2 schematically shows the position of the nozzle and the lower arm of the forming punch in the manufacture of a large diameter; in fig. 3 - the same in the manufacture of small-diameter pipes.

The crucible has a detachable housing 1 made in the form of a glass that is installed upside down. As a single unit with the body, the upper part 2 of the forming punch is made. To the upper part of the body and the shape of its punch are attached the middle part 3 of the crucibles and the middle part 4 of the shape of the punch, respectively. The nozzles 5 are attached to them with a forming surface 6 and the lower part 7 of the forming punch with the forming surface 8. A calibrating punch 9 is attached to the lower part of the forming punch. The forming and calibrating punches have through channels 10 and radial holes //. t

The crucible is collected for use. To do this, first connect the upper and middle parts of the body of the crucible and the forming punch and insert the appropriately prepared quartz block. Then screw the nozzle 5, the lower part 7 of the forming punch and calibrating nyasicoH 9. The assembled crucible together with the block is placed in an induction electric furnace. At 1,700-1,800 ° C, the glass melt in the crucible melts and through the annular gap formed by the nozzle and the lower part of the forming punch, leaves it in the form of a pipe, which is then fed into the exhaust machine. Crimping the calibrating punch, the quartz tube is calibrated to the inside diameter.

The upper part of the crucible body and the forming punch are made of low grade graphite, the middle parts are made of higher quality graphite, and the nozzle, the lower part of the forming punch and the calibrating punch are made of fine-grained, low-ash graphite of the highest quality. When forming quartz pipes of large diameter, the lower part of the forming punch has a height greater than the nozzle, and when forming pipes of small diameter, on the contrary, the ratio of the angle of the forming surface of the nozzle to the angle of inclination of the forming surface of the punch remains constant.

Silica vapors formed during heating of the block and pipe drawing are removed through the radial holes and through

0 channel in the forming and calibrating punches by purging with an inert gas. Due to the absence of cylindrical holes and grooves in the body of the crucible, the condensate does not fall back into the glass.

The steep corners of the paclon of the forming surfaces of the nozzle and punch prevent the glass melt from retaining in the joint zone of the nozzle, the body and the lower part of the forming punch. Glass mass does not respond

0 with graphite. Due to the good heating of the glass mass in the zone of shaping, the accuracy of quartz pipes is very smooth, requiring no further fire or mechanical processing.

5 Experimental verification has shown that in this crucible design it is possible to obtain very high quality calibrated quartz pipes. This increases the yield of products on

4-5%. and the specific consumption of graphite per 1 kg of pipes is reduced due to an increase in the service life of individual elements of the crucibles.

Claims (2)

1. USSR author's certificate number 487028, cl. From 03 to 05/08, 1974. 2. Bazanov, IM and others. Production of quartz tubes with selective spectral transparency, Glass and Ceramics, No. 1, 1975, p. 32-33. S