Tray Turn down Ratio
Tray Turn down Ratio
(OP)
We are designing a fractionation column that will be operating under wide feed rate operating range. Therefore, should we go for high or low tray turn down ratio e.g. 60% or 30%? For example, a valve tray would have turn down ratio of 5 to 1, which means the tray can handle 1/5 of the feed, while meeting specifications. Does this mean for a fractionation column that will be operating under wide feed rate operating range, I should use (1/5 x100) 20% tray turn down ratio? Or we should not report the turn down ratio in percentage at all?
Thanks for your calrification
Thanks for your calrification





RE: Tray Turn down Ratio
RE: Tray Turn down Ratio
The best we, the purchasers, can do is come up to the vendor's level of general knowledge in the design - but we should never assume the position of "expert" - unless we are willing to take on the related liabilities. That being the case, do the smart thing just as TD2K does: work with the vendors, giving them ALL your scope of work and letting them tell you what they can/can't build and what their limitations are and why. You basically want to know if they can meet your specifications; if there are any tradeoffs in meeting those specifications, you certainly want to know about them up front - with no post surprises.
This is the technique I've always used in specifying and purchasing major equipment as a project engineer and project manager. To do otherwise is not to take advantage of the maximum know-how a vendor can lend to a project in the area of special, proprietary design. Distillation trays and tower internals is that type of design.