On April 25, the project of soda recovery technology transformation for environmental protection promotion of Fujian Qingshan Paper Industry Co., Ltd. contracted by Changsha Branch of China Haisum Engineering Co., Ltd. passed the completion acceptance. This project boosted the environmental protection upgrading, process innovation, product quality improvement and output improvement at Qingshan Paper, and subjected the backward equipment and technologies that were not suitable for economic and social development to the transformation for quality improvement, emission and consumption reduction; the resulting "green transformation" pushed the production into a virtuous circle.

This project comprised the soda recovery furnace system #1 of Soda Recovery Plant I and the soda recovery furnace system #3 of Soda Recovery Plant II. The works for soda recovery furnace system #1 included the maintenance and reconstruction of the furnace body steam drum, air supply and distribution system, water cooled wall, platen superheater, superheater, economizer etc.; the daily solid treatment capacity was raised from 500 tds/D to 750 tds/D; the original DESP was overhauled, and a WESP system was added; the new hyperconcentration system at evaporation station #2 raised the concentration of output black liquor from 60% to 72%, while the water evaporation rate increased to 213 t/h. The works for soda recovery furnace system #3 included the maintenance and reconstruction of furnace body air supply and distribution system, water supply system, water cooled wall, boiler convection tube bank, superheater, etc., and the daily solid treatment capacity was raised from 780 tds/D to 950 tds/D; the original DESP was overhauled, and a WESP system was added; the new hyperconcentration system at evaporation station #3 raised the output black liquor concentration from 65% to 75%, and the water evaporation rate went up to 184 t/h; the dust emission concentration was ≤ 15 mg/Nm³. Changsha Branch won this EPC project through open bidding in February 2018, and the total duration of the contract was 10 months. The third-party performance testing and one cycle of trial production indicated that all indicators reached the design capacity and the pre-defined standards, and met the contractual stipulations and production requirements; the system functioned in a stable and reliable fashion, and was brought into service before the date specified in the contract.

During the implementation of project, the project team sought continuous optimization through continuous trials, and made an innovative use of the WESP technology for dust treatment of soda recovery to enhance the output of soda recovery system and the ultra-clean emission; that was the first successful application of WESP technology in soda recovery industry in China. The ecological development is in its key period, critical period and window period in China. Through the R&D and application of proprietary process technologies, Changsha Branch gathered broad experience in the construction of WESP projects for soda recovery furnace and large-sized environmental protection renovation projects. The Company will keep on following out the philosophy that "nature is the true treasure" in order to make room for future development.