3 replies to this topic

[Mohammed Magdy]

please can any one help me and tell me the steps for design Total Water Condenser
the attached file has all the details

Attached Files

•  Total Water Condenser.xlsx   33.93KB   29 downloads

[Art Montemayor]

Mohammed:

I have included my comments to your submitted basic data in Rev1 of your workbook.

Your instructor has done you a large favor by referencing a textbook that illustrates and shows how to calculate the condenser you are trying to describe. You should obtain a copy of Kern's "Process Heat Transfer" and study it before applying the manner to resolve the problem.

I really tried to find out what it is that you ae supposed to do with the data you submitted, but as you can easily identify by my remarks, you have a lot of learning to do in identifying what the scope of work and basic data for a problem are all about. I have not succeeded in making out what it is that you are describing and I don't honestly think it is me that has a problem.

I hope other members in our Forums more intelligent and astute can help you get oriented with what you have to do on this assignment.

Attached Files

•  Total Water Condenser Rev1.xlsx   35.89KB   21 downloads

[Mohammed Magdy]

first of all thanks for your reply i answered all ur question in excel file
please i want ur email or ur skype account please thanks in advance

Attached Files

•  Total Water Condenser Rev1 answered.xlsx   36.53KB   14 downloads

[Art Montemayor]

Mohammed:

I am going to try to respond to your plea for help by offering some examples of how engineering calculations should be done and executed and by offering some hints and recommendations that you should heed in order to comply with turning in your solution to the problem you have described in a very sad and deficient way.

Note that I am attaching my revised copy of your workbook titled “Total Alkylation Condenser Rev2”. Always renumber a revised version of an engineering document. That is the standard way of documenting all engineering work product and it is best you (and all other students) know this method as soon as possible because it will be the manner that you will maintain control of your documentation during your career. I had to re-title your workbook because you are not condensing water - and that is what the title said in English.

Please note and read what I have included in your workbook Rev2; I have added more comments and remarks that I consider to be of importance in showing you how to attack your problem:

• Always be specific and give ALL the basic data – that includes all units and identify if a pressure value is gauge or absolute;
• Abide strictly by the instruction given you. Research, compile, and identify all the physical properties you were assigned. Note that I have already done some of this for you – not to do your work for you, but to show you how easy it is when you put your mind and effort to it. You should be able to identify if the polyethylbenzene is condensable at 145 ^oC and 14.25 barA or not. Note how I have arranged the basic physical properties. You should be able to see via a simple table that only some of the components are going to be condensable; the rest are non-condensable at the condenser conditions.
• It is important for you to organize this basic data because by being able to tell how much of the stream is condensable, you can then make a logical and practical decision on what type of heat exchanger you will require to carry out the job;
• Again, be specific and write clearly about what your scope and basic data; are you instructed to use a vertical condenser as opposed to a horizontal model?
• Clearly identify what the name polyethylbenzene identifies: a specific compound or a series of different polymers? Is this a potential fouling agent or a desirable product? You lazily have given us very little information in your two posts – which are made up of only two sentences in each post. Without basic data and detailed information, we cannot give you much meaningful help. YOU have to help us in order for us to help you.
• The Kern condenser calculation example is not directly applicable to your assignment because it involves the total condensation of a pure compound, propanol. It also does not include non-condensables. However, the algorithm and the method of calculation are the same as you should apply to your project.
• Note that my calculations are made in a specific and well-detailed explanation for the reader to be able to easily follow the logic and method. This is important in order to convince your reader and checker (and your calculations should always be checked – preferably by a peer) that your calculations’ result is credible and worthy of being applied. It is not about neatness and good appearance; it is about generating a credible engineering answer to a problem.
• Note how easy it is to obtain free and available, detailed physical properties for some compounds by reading my references. Always cite your references. This is only one requirement to make your calculations credible.
• Study the various methods and models of possible heat exchanger configurations for your application. Take a practical outlook on what you are going to propose as the type of exchanger to use. Take into consideration the existence of non-condensables and make sure that you make mention of this in your calculations, stating how you propose to handle them and how they affect your solution.
• Additionally, take into account the possibility of fouling taking place. You make no mention of any fouling, so I can’t state that there will be some. If fouling is to occur, you must have the exchanger design that accommodates the ability to clean out the shell side (I’m assuming the water side will be clean). If that is the case, then a fixed tube sheet design is not desirable. This is just common horse sense.
• You should be making calculations to identify the vapor – liquid equilibria that is going to exist in your unit. You have 3 components that will drop out as condensate in your condenser: benzene, ethylbenzene, and possibly polyethylbenzene. You should run dewpoint calculations (manual or in a simulator) to determine how your condensation will take place and calculate the heat removal load.
• You should have the ability to vent off or remove the non-condensables (ethylene and ethane) and also determine if these will be dissolved in the saturated condensate product.

You have a lot of work in front of you and I won’t bother you with more detail because you should be hard at work now.

I believe I have identified the majority of what I believe you have to do and the workbook should indicate how you should go about it.

Good luck.

Attached Files

•  Total Alkylation Condenser Rev2.xlsx   178.74KB   25 downloads