The project titled "Research and Development of the Seven-effect Two-stage Energy-saving Evaporator", jointly completed by Henan Jiuye Chemical Equipment Co., Ltd., Xinfagroup Co., Ltd., and Zhengzhou Research Institute of Chalco (Aluminum Corporation of China), has for the first time achieved seven-effect two-stage continuous falling film evaporation in the alumina industry both at home and abroad, and has been successfully applied in Xinfagroup Co., Ltd. According to Ju Lirang, the chief project leader and General Manager of Henan Jiuye Chemical Equipment Co., Ltd., the developed two-stage continuous evaporation technology has significantly reduced the consumption of fresh steam. The innovative design of separate layouts for the heating chamber and the separation chamber ensures thorough vapor-liquid separation, resulting in pure evaporation condensate water that can all be used as soft water for boilers. The newly developed film distributor prevents the inner wall of the heating tubes from drying out or breaking the film, stably maintaining a high heat transfer efficiency, and realizing the overall integration of the seven-effect two-stage evaporation technology. It is reported that currently, the six-effect falling film evaporator is commonly applied in the alumina industry both at home and abroad. Most of its steam consumption is above 0.3 tons of steam per ton of water, and the best level is 0.28 tons of steam per ton of water. A set of 220t/h seven-effect falling film evaporator has been applied in the transformation of the alumina evaporation system in Chiping of Xinfagroup Co., Ltd. When the temperature of the original evaporation solution is 70℃, the steam consumption reaches 0.22 tons of steam per ton of water, and all the condensate water can be used for boilers. Compared with the six-effect evaporator before the transformation, the steam consumption is reduced by 0.08 tons of steam per ton of water, saving 150,000 tons of steam annually. Compared with the best domestic level, the steam consumption is reduced by 0.06 tons of steam per ton of water, saving 110,000 tons of steam annually, highlighting the remarkable energy conservation and emission reduction effects. This technology and equipment have an excellent energy-saving demonstration effect and can be comprehensively promoted in the alumina industry, saving 20 to 30 million tons of steam annually and creating an economic benefit value of 3.6 billion yuan. At the same time, this project can also be popularized and applied in the chemical industry and other industries, bringing significant economic and social benefits.