The silicon rods are confused due to bending. What causes this phenomenon, and how can it be resolved?
Thread Content
This post was last edited by jindin312 on 2011-3-2 at 14:44. Dear sea friends: Our factory is a new one that has just started operations and is currently in the debugging phase. In the previous phase, the temperature of the outer layer was always very low, which meant that the outer part of the silicon rods produced was always the thinnest. Recently, we have deliberately increased the temperature of the outer layer; although the temperature of the inner layer remains the highest, we ensure that there is not a large difference between the temperatures of the outer and inner layers. Yet, once the silicon rods are taken out of the furnace, the diameter of the outer layer is on average 10 mm larger than that of the inner layer. Moreover, due to the high temperature in the inner ring, the silicon rods bend. What causes this phenomenon, and how can it be resolved? ? ? ? Thank you. . .
This is due to an uneven distribution of the gas field in the reduction furnace, which results in uneven heat transfer. The gas inlet and flow velocity can be improved (increased), but not too much, otherwise it may cause the structure to collapse; meanwhile, the temperature should not be set too high, otherwise issues such as soft failure due to overheating may occur
Reply to 2# rhk2009: The way to improve the gas flow rate is simply to increase the feed pressure, which poses a challenge for the entire system! ! !
Reply to 1# 123419628: The low temperature of the outer ring is due to its proximity to the furnace wall. The reduction furnace has a jacket layer with HW cooling system, which removes more heat; therefore, it’s normal for the temperature there to be lower. As for the inner ring bending, it is due to the air intake holes; you can make adjustments, but it is still necessary to control the temperature and current well – the current value can be set a bit lower!
What the original poster mentioned about the silicon rods bending during later removal actually seems to be due to the cooling effect on the materials; moreover, a higher temperature in the inner area exacerbates this unevenness in the silicon rods. The feeding point can be improved accordingly
I think the silicon rod bends because the heating of the outer layer leads to an increase in temperature in the inner layer as well, causing the silicon rod in the inner layer to soften due to the high temperature. I suspect there are more ‘corn kernels’ in the inner layer; is that correct?
The low temperature in the outer ring is mainly due to the coolant water carrying away heat; uneven flow patterns occur when the silicon rods in the inner ring bend, which leads to uneven growth. It is necessary to control the temperature inside the furnace as well as the cooling water (oil), and to adjust the gas flow appropriately.
Reply to 6# cjzhx123: The surface of the silicon rod is relatively smooth. . . I would like to ask everyone: are there any standards for the dimensions and machining accuracy of beams? ? ?
Reply to 6# cjzhx123: Hello, could you send me the information on that aura you shared last time? My email address is 380483578@qq.com. Thank you!
Reply to 8# 123419628: The machining accuracy of the beam depends on the cutting tools you use. It depends on what shape it needs to have – whether the opening at the top of the silicon core is V-shaped or U-shaped – and it must fit properly; it’s best if it can be secured there, otherwise the beam might fall off during the gas displacement process. As for the size, it depends on the distance between your two electrodes; it shouldn’t be too short nor too long. Try experimenting a bit.
Reply to 10# Qingheying: The upper end of the crossbeam is stuck, but full contact cannot be achieved; there will be some gaps. . . . . .