Device and method for adjusting flame temperature of VAD and OVD on line

Abstract

The invention discloses a device and a method for adjusting the flame temperature of VAD and OVD on line. The device comprises a blow lamp and a sleeve arranged at the outlet of the blow lamp, wherein a heating device I sleeves the outer surface of the blow lamp; a heating device II sleeves the outer surface of the sleeve; a part, close to the outlet of the blow lamp, of the prefabricated rod loose body is adopted as a deposition area of the prefabricated rod loose body; a pair of heating devices III are arranged close to the deposition area; and the heating devices III are arranged in front of and behind the deposition area. By adopting the device and the method disclosed by the invention, the stability of refractive index profile distribution of an optical fiber prefabricated rod is improved. As the refractive index profile distribution of the optical fiber prefabricated rod and the stability of the refractive index profile distribution can be affected by the flame temperature and the temperature of the deposition area, the temperatures of the flame and the deposition area are controlled by using an external heating body (a graphite resistor or a resistance wire), the temperature control precision and the stability are both good when being compared with pure combustion flame, and the result shows that the refractive index profile distribution of the optical fiber prefabricated rod can be relatively precise and stable.

Description

technical field [0001] The invention belongs to the field of optical fiber prefabricated rod manufacturing, in particular relates to a quartz blowtorch for VAD and OVD, and more specifically relates to a device and method for online adjustment of VAD and OVD flame temperature. Background technique [0002] VAD (Vapor Axial Deposition) and OVD (Outside Vapor Deposition) processes are currently one of the best processes for preparing low water peak or zero water peak single-mode optical fiber preforms. Due to its good process stability and high deposition rate, VAD and OVD processes are widely adopted by mainstream optical fiber preform manufacturers at home and abroad. [0003] The equipment body of VAD and OVD process mainly includes three parts: chemical vapor reaction deposition chamber, blowtorch and loose body preform lifting and rotating mechanism. Among them, the blowtorch is one of its most critical components, and its main function is to convert the reaction gas int...

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Problems solved by technology

[0012] The thermodynamic properties and hydrodynamic properties of the reaction flame are usually a contradiction in the process of process practice: in order to meet the hydrodynamic properties of the flame, the speed of each gas injected from the burner channel needs to be reasonably controlled to meet the requirements of the jet flame. The laminar flow conditions of the gas; and in order to achieve the thermodynamic conditions in the reaction process, the combustion gas (H 2 , O 2 and CH 4 etc.) The flow rate usually needs to be adjusted according to the ambient temperature and the flow rate change of the raw material gas, and this adjustment will generally destroy the original hydrodynamic properties

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