Upflow design versus downflow design for digestion flash train
Upflow design of digestion flash vessels, with deflection of the incoming flow onto a controlled slurry level, allows the factors affecting three-phase flow to be managed more effectively when compared to downflow design. Upflow design results in lower rates of scale formation on vessel walls, and lower rates of particulate carry-over in the vapour. Downflow design is simpler from a fluid mechanics point of view, and the need for little or no control, makes it operationally attractive. This benefit however does not necessarily translate to lower capital and operating costs. Downflow designs are more capital intensive as they experience higher rates of wear on vessel walls and interconnecting piping. Due to the added level of operational complexity, the success of an upflow design is more dependent on careful engineering design using appropriate analytical methods. A correctly designed upflow flash train will result in better equipment performance, somewhat lower piping costs, lower flash tank elevation, less or no erosive wear, less maintenance, less down time and better quality vapour. Hatch inhouse developed software has been used to design and analyse both types of design. In this paper, the relative merits of both upflow and downflow flash train design will be discussed in terms of capital cost, operating and maintenance costs, and performance.
Flash Train Upflow Downflow
Tran Quoc-Khanh
The Hatch Building 144 Stirling Street, Perth, WA 6000, Australia
国际会议
XVIII International Symposium of ICSOBA(第18届国际铝土矿、氧化铝及铝工业学术年会)
郑州
英文
231-237
2010-11-25（万方平台首次上网日期，不代表论文的发表时间）