Transmission channel and nozzle optimization of silicon drying cylinder based on CFD

Abstract

The irregular distribution of hot air flow within the rotary drying cylinder of an automatic silicon material cleaning machine will result in uneven silicon drying. This research presents on-field measurements and 3D Computational Fluid Dynamics (CFD) models to analyze the velocity and flow distribution within the gas flow channel of the rotary drying cylinder. Factors including inlet diameter, inlet velocity, outlet diameter, transmission channel segmentation, nozzle diameter, and spacing substantially influence the flow uniformity characteristics within the drying cylinder. A new truncated cone three-segment channel model is built based on the experimentally verified cylinder model. Given an inlet velocity of 30 m/s and an inlet diameter of 40 mm, the outlet diameter is reduced from 40 mm to 30 mm. Additionally, the nozzle configuration transitions from a uniform distribution along the transmission channel to an uneven distribution, with nozzles at the front, middle, and end sections having diameters of 1.5 mm, 2 mm, and 2.5 mm, respectively, and spaced at intervals of 20 mm, 10 mm, and 15 mm. The novel design can efficiently mitigate gas flow loss throughout the channel, ensuring uniform flow to the nozzle and markedly enhancing the drying efficiency of the silicon material. The optimized model's drying time is diminished by 25 % relative to the prototype model while drying efficiency has improved from 78.4 % to 84.1 %.