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  • 1.  Crystallization

    Posted 11-12-2019 05:10
    Hello !

    I am currently studying industrial crystallization process. I want to know how can we link crystallization of calcium nitrate with solution viscosity, temperature and concentration of calcium nitrate. I have noticed that when concentration decreases i.e. water increases in solution, the time taken to achieve crystallization point and delta T till that point also increases. Please discuss on the effect on overall heat transfer coefficient because of viscosity changes

    Thank you.

    Haider Ali

    GIK Institute of Engineering Sciences & Technology

  • 2.  RE: Crystallization

    Posted 11-13-2019 02:25

    Hello Haider Ali,

    My first question is why are you studying this industrial crystallization process?

    If you are studying it for a grade in school.  Find out why the overall heat transfer coefficient and viscosity are important to your professor. Then find out this person's recommended way to measure these things.  I am not the best one to help you.  In academia, your professor is the person to learn from as to what they really want from you.

    If you are studying it for a client that seeks better calcium nitrate crystals. Find out what 'better' means to your client (Purer crystals, Lower cost, Faster output)? What instruments do you currently have on their existing crystallizer? Are they seeking to get crystals by evaporation or by cooling a supersaturated solution?

    With evaporation, when you add too much heat too fast to drive evaporation the calcium nitrate decomposes. 

    With supersaturated solutions, you leave most of the product in the crystallizer as a liquid, and may not get all the crystals you seek.

    Step 1 for me is to plot the desired parameters (amount of 'better' crystals) against the variables you can easily measure. (time, volume, remaining mass, temperature, rate of temperature change, energy input <amps if electric> <volume of condensate if steam>

    This is easily collected data, which you may already have from past production runs or you may have to collect some of it going forward with future production.

    If this a future process, you can gather the answers in glass on a small scale and make the decisions you need for scale-up and investment from the glass data.

    With a few simple plots, the answers you are seeking should become obvious to you.

    With these plots in hand, I doubt you will need to come back to this forum, but if that is not the case, I will gladly help you interpret the data you have and suggest your next step.


    Good Luck!

    Mark DeLuca
    Levittown PA

  • 3.  RE: Crystallization

    Posted 30 days ago

    TO:  Haider Ali


    If you are in an academic setting, I suggest you refer to Mullin, J.W. (2001)  Crystallization  4th edn.   Butterworth-Heinenmann, Oxford.


    Good Luck,


    William B. Woods

    Retired Chemical Engineer

    Weyers Cave, VA


    Sent from Mail for Windows 10


  • 4.  RE: Crystallization

    Posted 30 days ago
    If you are in an academic setting, I suggest the following reference, Mullin, J.W. (2001) Crystallization 4th edn. Butterworth-Heinenmann. Oxford.

    Good Luck,

    Willian Woods
    Retired Chemical Engineer

    William Woods
    Weyers Cave VA