3 replies to this topic

[maud]

Am still busy designing my column, though am conerned about the 18.6m height and 4.4m diameter I got. I was told that the ratio(H/D) of the two should be less than 20. I cant exactly visualise how big is such a diameter and the height, do they make sense?

[Art Montemayor]

Maud:

If you are a Chem Eng student, one of the first things you should learn - for your own development and benefit - is to communicate with specific data and facts. You fail to tell us the specifics:

1. What specific fluids are you distilling? What are their volatilities and other properties? What are the concentrations? What are the desired products and their concentrations?

2. What type of column are you talking about? Is is a bubble cap design? Valve trays? packed? What type of packing? etc. etc.

3. How did you calculate height? Or did a computer program do the process design? Is it a simulator? If so, which one? Have you done a manual, simple check calculation besides a computer run?

4. How did you calculate the diameter? Did you employ the Brown-Souders relationship? If you're using trays, what spacing are you allowing - and why?

5. What is your reflux ratio? How did you determine it?

6. Who, specifically, told you that the L/D ratio should be < 20? Another student? Or was it a knowledgeable and experienced person? What was the explanation for citing that value?

As you can see, I believe you've failed to communicate in an engineering way to an engineering Forum. Big mistake. You're always going to get a response like mine when you give other engineers flawed or incomplete information. You should be prepared to fully describe and detail out your problem or application. Engineers work with specifics and hard data. We need it to make sound engineering judgment decisions.

Start again and give your description of the distillation problem you are working on another try. I'm sure we can be of some help to you in understanding or whipping the problem facing you. But you've got to help us with hard and specific basic data.

I'll await your reply.

[djack77494]

Maud:
Point of fact: Your H / D ratio IS less than 20.
It is 18.6 / 4.4 = 4.23

[sarahx87]

Am still busy designing my column, though am conerned about the 18.6m height and 4.4m diameter I got. I was told that the ratio(H/D) of the two should be less than 20. I cant exactly visualise how big is such a diameter and the height, do they make sense?

is this from year 2006??? lol. simple question and simple answer. YES they do make sense.

i cant give u much explanation, as i am very a newbie for chemical engineering(though im in 2nd year).
but, here a link : http://www.answers.c...lation-column-1 not 100% trust the web, but i'll dig some books to look out for the answer.