4 replies to this topic

[Syed saqib ahmed]

A multi component feed of different composition enter the column at 3 different trays and column has 1 side reboiler and an bottom reboiler but it has no top reflux according to our design and desired product is obtained.
But problem in desiging the column without reflux.what method did we choose?if any method please guide us.
Thankyou in advance.

[Art Montemayor]

Syed saqib:

 

For your own benefit and improvement, please learn and practice concise, accurate, and detailed communicating of information and data.  It is of utmost importance if you are to succeed as a Chemical Engineer.  You make a statement of what appears to be a copy of a given distillation design problem and then you state that you have a problem designing the column without any reflux.  Were you told to design the column without reflux?  Or did you (or your design group) decide to avoid reflux?  Please be clear and concise.

 

Your statements make little or no sense because you don’t give us details and basic data.  We can’t help you if you don’t tell us the whole, exact, and detailed story.

 

Are you thoroughly knowledgeable in what occurs in the Unit Operations of distillation of liquid mixture streams?  Are you aware that a basic distillation column is made up of a Stripping Section and a Rectification Section?  Why do you refer to a Stripper column in your thread title if you are dealing with a Distillation column?  Are you designing a stripper or is it a distillation column?  Please be specific in your description.

 

This is not about language ability; it is about transmitting your thoughts and ideas in a correct and accurate manner - whatever your primary language is.  The ability to communicate efficiently and accurately is what engineers are expected to do as their job.  As a professional engineer you will not build, fabricate, transport, install, and operate a distillation column.  But you will certainly be expected to communicate all the necessary instructions and supervision to see that it is all done for you correctly, efficiently, and on time.  To lead successfully, you must be capable of communicating accurately to those under you that do the actual work.

 

Await your reply.

[Syed saqib ahmed]

Thanks sir for your advice,
We have an cryogenic nitrogen rejection unit.process pfd we have to design an stripper in which we have top and bottom feed(multicomponent) and 1 side reboiler and bottom reboiler.in this system we don't have top reflux from my khowledge it is required for calculating number of plates.for minimum number of plates what method should we select.

[Art Montemayor]

You persist in failing to communicate correctly and accurately.

 

Please tell us exactly what you are doing:

• Have you been instructed (or ordered) to design a stripper tower?  Or is the selection of a stripper tower your decision or idea?  Please answer all my previous questions and these also.
• You state you have a cryogenic nitrogen rejection unit (whatever that is).  Please submit an accurate PFD (Process Flow Diagram) with all streams labeled so that we can all identify what it is that you are attempting.
• Have you developed the process flow diagram?  Or was it given to you by your instructor? 
• Are you doing this as an assigned problem by your instructor?  Are you doing this by yourself or are you part of a student design group working on the same problem?

Give us all the details and we can offer comments and advice.  But we can’t respond without ALL of your basic data in hand.

[Syed saqib ahmed]

Sir the process scheme was given by our instructor.column top product at a temp of -115•c so if we use top reflux,we have to enter it at a temp less than 115c for this we required external cooling cycle(i.e:helium)but it is expensive so we want to run our column with top reflux.
My question is how to find number of plates if the column has no reflux and the feed is multicomponent.