Burner for growing crystals by flame fusion method

Abstract

The invention discloses a burner for growing crystals by a flame fusion method. The burner comprises a conical feeding port, a central pipe, a hydrogen inlet, an external oxygen inlet, a hydrogen ring-shaped pipeline, an external oxygen ring-shaped pipeline, a crystal growing chamber and a crystal growing base, wherein the conical feeding port is connected with the central pipe; powder and oxygenare fed into the central pipe from the conical feeding port; the central pipe is externally provided with the hydrogen ring-shaped pipeline; hydrogen is filled into the hydrogen ring-shaped pipeline by the hydrogen inlet connected with the hydrogen ring-shaped pipeline; the hydrogen ring-shaped pipeline is externally provided with the external oxygen ring-shaped pipeline; oxygen is filled into theexternal oxygen ring-shaped pipeline by the external oxygen inlet connected with the external oxygen ring-shaped pipeline; the tail ends of the central pipe, the hydrogen ring-shaped pipeline and theexternal oxygen ring-shaped pipeline are respectively communicated with the crystal growing chamber; the crystal growing base is arranged in the growing chamber. The burner disclosed by the inventionhas the advantages that the radial and axial pressure distribution of the burner can be greatly reduced, so that the radial distribution of the oxygen is more uniform, oxygen vacancy of the crystal is reduced, the size and the uniformity of crystal growth are improved and the crystal quality is improved.

Description

technical field [0001] The invention belongs to the technical field of crystal material research, in particular to a burner for growing crystals by a flame fusion method. Background technique [0002] The traditional flame fusion crystal growth burners are two-tube burners. The height of the furnace body is 250mm, the outer diameter is 180mm, the inner cavity of the furnace is a truncated cone, the upper diameter is 40mm, and the lower diameter is 60mm. The refractory layer in the furnace body is made of corundum powder and clay, the insulation layer is filled with asbestos, and the outer wall is a cylinder made of 1mm thick steel plate. The diameter of the central hole is 4mm, which is used to feed oxygen and oxide powder, and 12 hydrogen holes with a diameter of 2mm are evenly distributed on a circle with a diameter of 18mm. When working, oxygen and oxide powder enter the combustion chamber from the upper part, and the oxygen and the hydrogen fed into the external tube a...

AI Technical Summary

Problems solved by technology

The disadvantage of this two-tube burner lies in three aspects: first, the flame provided is concentrated on the top of the melting cap, and the radial temperature gradient of the melting cap is large, which makes it difficult to grow crystals with broad shoulders, and it is not easy to grow into large-sized crystals. It is not possible to reduce the radial temperature gradient by reducing the diameter of the central nozzle, because after the diameter of the central nozzle is increased, the flow of oxygen must be maintained to prevent tempering, causing the calorific value to exceed the requirement and causing the local temperature to be too high; secondly, too concentrated airflow As a result, there is a large gradient in the axial and radial pressure distribution around the melt in the furnace, resulting in uneven composition of the grown crystal and affecting the quality of the crystal; finally, because some oxide crystal growth defects largely depend on the oxygen vacancies in the crystal , such as yttrium lutetium silicate crystal, if the oxygen distribution is uneven or the oxygen-deficient environment will increase the crystal oxygen vacancies, seriously affecting the optical properties of the crystal

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