【Ten Years of Great Progress in Chemical Technology】Hualu Company’s polysilicon production technology won the Silver Patent Award in China from 2014 to 2023

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This post was last edited by “Fish Swimming in the Desert” on September 6, 2023, at 13:15. Over the past decade, there has been tremendous development in chemical engineering and technology; truly, it’s a glorious era for China’s prosperity and strength! This post serves as an opening gambit to encourage more participation from everyone—the community becomes even more vibrant with your involvement. With you here, Huachuan becomes even greater! This is a continuously updated compilation post on “Ten Years of Great Development in Chemical Engineering Equipment”; all are welcome to join the discussion: https://bbs.hcbbs.com/thread-3576046-1-1.html. Let us enhance our awareness of quality and strive for high-quality development. ----------------------------------------- Recently, the National Intellectual Property Administration announced the list of winners for the 24th China Patent Awards. The invention titled “A method for improving the efficiency of reduction deposition reactions in polysilicon production,” submitted by China Chemical Engineering Hualu Engineering Technology Co., Ltd., won a Silver Award. As the current mainstream production method for polysilicon, the modified Siemens process utilizes high-purity chlorosilane to carry out vapor-phase deposition reactions in a reduction furnace in order to produce high-purity polysilicon. At temperatures of 1050–1080°C, the chlorosilane is reduced to silicon on the surface of the silicon core, and this silicon is continuously deposited there to form polysilicon rods. As the production facility for polycrystalline silicon as the final product, and also as the main energy-consuming unit in the polycrystalline silicon production process, the importance of the polycrystalline silicon reduction device is self-evident. The efficient operation of this device plays a decisive role in both product quality and energy consumption. The vapor deposition reaction in polycrystalline silicon reduction equipment is a multi-variable and complex production process, influenced by various factors such as the structure of the reduction furnace, the operating temperature and pressure inside the furnace, the molar ratio of feed materials, the feeding growth curve, the inlet and outlet nozzles, the temperature of the cooling water, the applied current, and the arrangement of silicon rods. Ke Zengpeng, deputy general manager of the Materials and Energy Division at Hualu Company, told reporters that through extensive research and efforts by the polysilicon technology team, and based on breakthroughs in mechanism understanding, simulation validation, innovative practices, as well as years of accumulated experience, it was for the first time proposed to use separate vaporizers and superheaters for silicon trichloride hydrogas and silicon dichloride hydrogas, so that these gases can be vaporized and superheated separately. The silicon trichloride hydrogas, silicon dichloride hydrogas, and high-purity hydrogen then enter the reduction furnace through their own separate flow control units, entering at the appropriate times, in the right proportions, and at the suitable flow rates to undergo the reaction. That is, at the initial stage of the reaction, a larger proportion of dichlorodihydrosilicon is introduced into the reduction furnace, allowing the silicon core to grow rapidly at the beginning and thereby improving the system’s deposition efficiency ； To prevent adverse phenomena such as \"atomization\" in the reduction furnace, the feeding of dichlorodihydrosilane is stopped in the later stages of the polysilicon deposition reaction. This improves the quality of the polysilicon product and production efficiency, while also preventing the formation of amorphous silicon powder and avoiding system blockages. The implementation of this portfolio of patented technologies enables polysilicon manufacturers to improve the efficiency of reactive deposition, shorten reaction cycles, increase the effective conversion rate of trichlorosilane, reduce the volume of material circulated in the production system, thereby significantly lowering the operational costs and investment required for such facilities. It is reported that the China Patent Award is the only **departmental award in China dedicated to recognizing inventions and creations for which patent rights have been granted. It represents the highest honor in the field of patents in China, is recognized by the United Nations World Intellectual Property Organization (WIPO), and holds significant influence on the international stage.