Please recommend a tray technology with high operational flexibility

In this case, the best approach is to block the holes in the trays at the initial stage, and then remove those blocks after adjusting the load. If I must give a recommendation, I would suggest a type of tray from my alma mater: the Radial Side-Guided Jet Tray (CJST). http://www.new-vst.cn/Html/Procn141_3.html It offers good operational flexibility: compared to ordinary trays, these trays have a higher kinetic energy factor F0 for their tray holes, which reduces the likelihood of abnormal phenomena such as liquid flooding in the downcomers or excessive entrainment of liquid foam. In other words, the upper limit of its operational kinetic energy factor is high, while its lower limit for operational flexibility is comparable to that of floating valves; the upper limit is slightly higher than that of floating valves. This post was last edited by 263525689 on 2009-2-11 15:18]

In this case, we use a combination of light and heavy floating valves.

Thank you all for your support. In fact, after the start of the second phase of the project, the operation of the tower was largely within normal parameters; therefore, blocking the holes is a good approach. However, during the technical discussions, the design institute favored the use of fixed-valve trays, and it was stated that their operational flexibility was 50% to 110%, just like that of floating valves. I believe the actual flexibility of floating valves should be much higher than that of fixed valves, not to mention the fact that floating valves allow for holes to be blocked in advance……

For your type of operating conditions, a floating valve tray should be used; the opening height of the floating valves can be adjusted, either by using weights on the valves or by blocking certain holes； Generally speaking, with a load of 30%, floating valve trays hardly require hole plugging; a slightly higher reflux rate is sufficient during operation. For equipment modification, JCPT trays (patented products of Tianjin Xintianjin Technology Development Co., Ltd.) can be selected.

I agree with LTY’s suggestion; using a combination of light and heavy valves is more appropriate.

I came across a project that involved intermittent operation, with the second operating condition requiring 4 to 5 times the amount of operation as the first condition. Initially, a mixed operation approach was adopted, but the final opening ratio chosen during the design process had issues, resulting in unsatisfactory outcomes. According to theoretical calculations, mixing light and heavy valves can resolve these problems; however, in practice, both light valves and heavy valves remain in a fully open state, failing to reach the partially open state described by theory. In fact, in this state, due to the weight of the floating valve, it is the kinetic energy factor of the valve orifice that is affected, that is, the injection rate of the vapor phase. Therefore, the most crucial aspect of this design is to select a reasonable opening ratio and an appropriate ratio of light to heavy floating valves.

30%-130%; the operational flexibility ranges from 1 to 4.4. Many types of trays can meet your requirements, such as floating valve or bubble cap trays – the specific choice depends on the application

3D tray technology is employed to enhance operational flexibility. Challenge: There are two operating conditions – with and without bottom heating for the feed – resulting in a gas-phase load difference of 10 times； The minimum opening ratio is low, less than 2%. Solution: Use 3D micro-narrow strip valves to increase the valve density in order to accommodate lower gas-phase loads ； Special valve arrangement measures are adopted to broaden the operating flexibility range ； A trapezoidal outlet profile is used to replace the single overflow with a double overflow, reducing the flow intensity from 130 m3/m•h to 84 m3/m•h. This post was last edited by 263525689 on 2009-2-11 15:26]

What type of tray has an operating flexibility of 30% to 130%? As far as I know, the operational flexibility doesn’t cover such a wide range! I think this is probably theoretical data; it’s impossible to achieve this in actual operations. Last edited by kent0801 on 2009-2-11 16:26]

I feel the same way, but the promises made by tray manufacturers are only 50–110% or 60–120%; a higher reflux rate comes at the cost of increased energy consumption :)

The elasticity of a vertical mass transfer tray that was recently discussed can reach 5.5~7.X :)

Wow~~ The elasticity of trays these days can be so high! I’m just starting out in this field; usually the elasticity of trays I’ve come across ranges from 70% to 120%. Maybe it depends on the area where movement occurs. I’m still learning about this

Henan Yuhang’s vinyl chloride distillation tower has a design capacity of 70,000 tons using floating valve trays; after internal component modifications with the adoption of CJST radial side-guided spray trays, its production capacity increased to 130,000 tons. It has excellent anti-clogging performance and resistance to foaming-induced flooding, ranking absolutely first in terms of overall indicators. This post was last edited by sapphire2004 on 2009-2-13 11:41]

The technology of Tianjin University Beiyang **Distillation Technology Company is definitely better than that of those inferior companies

I’m not sure if the original poster eventually found a suitable tray; I’ve encountered a similar problem recently, with the operating flexibility of the column being as low as 25%. If there are any appropriate solutions, I hope the experts here can offer some advice

With such great flexibility, is it really safe to use in design? If we go by laboratory data, regularly structured packing is even better. The liquid load can range from as low as 0.2 t/m2·h to as high as 12 t/m2·h; operation is possible when the F factor is above 0.4, with an optimal F factor of 2–2.5. This elasticity should be above 5.