Print page

Print page

Checking columns internals

Q: What are the most important things I should pay attention to while checking the columns internals such as tray, beam, supporting rings and so on in the pre-installing process?

A: Not much to add over what appears in my recent CP article. For trays, levelness is important. As the trays are being installed, one should also check for weir height, downcomer outlet opening clearance and fit-up of the deck panels. If there are manways, you should make sure that they are in place and secure. If you are working with sieve trays before installing, you should check the orifice size and count and for valve trays. Make sure the valve legs have been sufficiently expand that the valves will not come out when in use. If the tower contains trays with different percentage open area or valve counts, make sure that the correct trays are installed in the right location in the tower.

Here are more of the latest questions on: Distillation

Is there a guideline for setting the height of the conical section of a column?
I have designed a column with two sections of different diameters (enriching section 1,900 mm and stripping section 3,500 mm). Is there any rule or guideline to be followed to set the height of conical section of column between these two diameters? Presently I have considered height of conical section as 500 mm approx (equivalent to one manhole) between these two diameters.

Is vacuum distillation best to recover iso amyl alcohol and manufacturing esters?
I'm planning to set up a distillation unit for distilling fusel oil to recover iso amyl alcohol and manufacturing esters from it. I've been suggested to go for vacuum distillation through use of watering pump and reboiler of falling film evaporator type. The column will be about 10m high having a diameter of 0.6m. Is this the right way to go? Which packing should I consider? Will vacuum distillation break the azeotrope formed between water and ethanol?

Is there a good way to calculate the height of stage in a distillation column?
I'm working on a distillation column for a six-part multi-component distillation column. It contains structured packing. I estimated about eight stages with a model and came up with approximately the same answer with pseudo-McCabe-Thiele. I was careful to pick the correct heavy key and light key. Then, I realized I did not have a good way to calculate the height of stage. The model, like most, only tells you the number of stages not the height of stage or Z, the final height of theoretical packing.

Kister would say 1-3 feet as an assumption (based on gas resistance), or I could estimate it using a KG or KL. Empirical data would help.

I assume that the oil, a collection of C10+, would pose the greatest resistance, which makes calculating an H stage even more difficult. The feed is trace water, toluene and oils.

Any advice or reference that might be useful in solving this dilemma?

How do I calculate the void space in a column?
How do I calculate the void space in a column? Actually we are putting ½-inch balls in a 14-inch pipe. Height of packing will be 3 inches. Above the ½-inch balls we will put ¼-inch balls and the packing height will be the same (3 inches). How many balls can I put in the column?

How does a water draw off vessel work?
I need to design water draw off vessel. How does a water draw off vessel work?

Back to Ask the Experts