WATER- COOLED SHAFT

The shaft is used in crystallization installations for the growing of high-temperature optical crystal out of melt. It has a simplified design, allowing to ensure an optical observation channel and the temperature measurement of the container by optical or other methods with maximum ratio between the cross-sections of the optical channel and the shaft. The water-cooled shaft consists of water-cooled part and sealed optical channel. The water-cooled part consists of external (1) and internal (2) pipes, positioned coaxially and closed at the upper end with a cap (3), and at the lower end - with a hollow body (4). The upper end of the external pipe (2) has external thread for connection with a container carrier, and the space between the external (1) and the internal (2) pipe is divided into two volumes (5 and 6) by two helical barriers (7 and 8). The sealed optical observation channel is shaped in the internal pipe (2).