The development of tray technology

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Tower internals are divided into three main categories: tray trays, structured packing, and random packing. The V-1 floating valve tray (or F1 floating valve tray), Mellapak structured packing, and IMTP random packing are typical representatives of these three types of tower internals. For a long time, these three types of tower internals have held a large market share in their respective application areas, and this situation is set to continue for a long time to come. The development of tray technology: The V-1 floating valve tray is a product of the American company Gritsch, and for decades it has been the benchmark product in tray technology. In the 1980s, the SuperFrac high-performance tray was introduced, bringing a series of new design concepts such as miniaturization of floating valves, enhancement of bubbling, optimization of downcomers, and elimination of liquid retention, thereby raising the level of tray design to a new height. However, the SuperFrac tray structure is complex, costly, and difficult to install. Entering the 21st century, research on tray plates has focused primarily on the downcomer; by optimizing its structure to enable liquid distribution and guidance, the efficiency of the tray plate can be improved. Float valve trays: In China, the V-1 float valve tray is referred to as the F1 float valve tray. 20 years ago, the vast majority of plate towers in China used F1 floating valve trays, with only a small number using guided floating valve trays. The guiding float valve uses a strip-shaped float valve with guiding holes. Guidance is used to eliminate the liquid gradient on the tray, while strip float valves are employed to prevent rotation. In addition to guide float valves, there are also trapezoidal float valves and other float valves with rather special shapes in China. Some of these float valves, in addition to serving guiding and anti-rotation functions, also have the capability to increase the density of airflow disruption by the float valve. Obviously, most research on floating valve trays in China focuses solely on enhancing the functionality of the floating valves themselves. Screen trays are another major type of tray; although their performance is slightly inferior to that of floating valve trays, they are still widely used abroad. The sieve plates used as bubble units have seen little improvement, but there have been many advancements in areas such as downcomers and the way tray plates are connected; the MD tray plate is the most representative example of these improvements. The MD tray combines the multi-downcomer technology with the sieve tray design, offering a high processing capacity; however, its tray efficiency is low, and its overall performance is not competitive enough. There is limited research on sieve trays in China; only inclined-hole trays exist, which can be regarded as an improvement on sieve trays ； The DJ tray is an improvement over the MD tray; it also belongs to the category of sieve trays, but its technical focus lies in multiple downcomers. The vertical sieve tray tray, also known as a three-dimensional mass transfer tray, is a type of tray with a hydraulic behavior completely different from that of conventional trays. Although it has not been extensively studied abroad, significant progress has been made in China, and its industrial application in certain industries has also been successful. Fixed-valve tray plates: In recent years, the use of fixed-valve tray plates has increased steadily, and more attention is being paid to this technology. The fixed valve is a bubble column unit that lies between the floating valve and the tray; its lower operating limit is similar to that of the tray tower, while its separation efficiency is close to that of the floating valve tray. Theoretically, any type of floating valve tray can have a corresponding fixed valve tray; the small floating valves produced by Grich Company in the United States come with corresponding fixed valves. Over the past decade, trays have been the focus of research in China’s tower internals industry; their performance has continued to improve, and their application level has also risen rapidly.