Design Of Electric Furnace Based On Chemical Vapor Deposition And Heating Process Analysis

Furnaces are special equipment for the production of preforms.During drawing process of perform,there are resistance heating,flame heating,high frequency induction heating methods.Through continuous feeding the mixed gas into a high temperature furnace,so that the gas particles are deposited on the light bar.By continuous deposition,the preform is formatted.In order to produce a good quality preform,which requires high-temperature furnace operating at temperatures above 2000 ℃,therefore,the preferred graphite furnace.The main purpose of this research is based on laboratory research and experimental needs,design the optical fiber preform drawing furnace structure has a high heating temperatures,including the selection of high-temperature furnace outer shell and exterior design,materials fire-resistant layer,insulation layer selecting,calculating the thickness of the insulation layer,the shape of the heating member design and choice of material;and the temperature detection of the temperature control system is studied,and proposed a method used for laboratory,to detect and control temperature for high temperature furnace,in the laboratory,using XTMA-1000 series intelligent digital display regulator,and use the furnace by PID control method to achieve real-time temperature control and testing.We use ANSYS software to simulate the temperature distribution in high temperature furnace,including the temperature of the heating of the air layer near the surface and distribution;The temperature distribution when the heating element diameter changes;The temperature distribution when the attachments on the heat generator.Next,We test the temperature performance of furnace,including in the heating process,the heating rate of the high temperature furnace;We test the ability of keeping temperature stability of high temperature furnace when achieving the temperature of making perform;When the preform is created,we will stop power supply,then observe high-temperature furnace at a cooling rate with water cooling effect.Experimental results shows,high-temperature furnace heating fast,fully capable to ensure fast reaching a very high temperature;when this temperature is reached,it can ensure a long-temperature stability;After fabrication,can quickly down to room temperature.These results shows,the design of high-temperature furnace can meet laboratory standards.Finally,We use MCVD method to fabricate optical perform.The results shows,the design of the furnace to meet the actual demand.