Home Cosmetic Science Talk Formulating How to know how much heated water has evaporated during lotion manufacturing?

  • How to know how much heated water has evaporated during lotion manufacturing?

    Posted by abdullah on August 25, 2021 at 8:46 am

    Is there any theory or way to calculate how much water has evaporated during lotion manufacturing if the work temperature is above 60°c? 

    How do you guys calculate yours? 

    abdullah replied 2 years, 7 months ago 5 Members · 11 Replies
  • 11 Replies
  • abdullah

    Member
    August 25, 2021 at 10:03 am

    The batches are 50kg and 200kg. 

    To find the evaporation rate of water i did an experiment. I heated 200g water to 60°c. After 5 minutes the temperature dropped to 57°c and 2g water evaporated.

    Is this the correct way to evaluate? 

  • PhilGeis

    Member
    August 25, 2021 at 10:21 am

    You need to determine this yourself.  

  • abdullah

    Member
    August 25, 2021 at 11:27 am

    @PhilGeis hahaha yeah but knowing how you guys are doing it would help me a lot.

    I did the experiment on 200g water to find the evaporation rate of water but at 200kg the evaporation rate is far less than 1% at 5 minutes. So this was not helpful 😃

  • oldperry

    Member
    August 25, 2021 at 12:30 pm

    The answer is going to depend on too many factors to make it easy to calculate.  Mixing speed, surface area, surface temperature, composition of formula, atmospheric humidity, etc. 

    You’ll have to make a big batch 200kg and weigh it before and after.  Do that about 30 times and you’ll get an answer that reflects the normal distribution of the process.

  • PhilGeis

    Member
    August 25, 2021 at 12:35 pm

    “Yield” what you get out of your production - as Perry said, is fairly unique to formula and process.

  • graillotion

    Member
    August 25, 2021 at 6:16 pm

    Only way is to make a batch…and weigh in and weigh out.  Too many factors….from time it takes to reach temp…surface area involved, relative humidity…and the list goes on….and on.  Example….if you heat a small batch quickly in the microwave…it will lose FAR less water than the same batch heated more slowly on a lab plate.

  • bill_toge

    Member
    August 25, 2021 at 8:32 pm
    if you keep your vessels closed when not adding materials, and minimise the size of the head space above the surface of the batch, water loss will be proportionately very low, especially when compared to the lab scale
  • abdullah

    Member
    August 26, 2021 at 1:52 am

    @Graillotion for up to 10kgs batch that is the way but for 50kg and 200 kg I don’t know how to weight it. Do you know any device fot that? 

    Also for 50kg and above i use inline homogenizer so some of them  would be inside the pipe, although can fill the pipe and check how much material fits there. 

    Another problem is the evaporation rate is different for different sizes. 
    For smaller batches the evaporation rate is higher than large batches so I can’t guess it from measuring it. 

  • abdullah

    Member
    August 26, 2021 at 1:57 am

    @Bill_Toge thanks. That looks like a good idea. 

  • bill_toge

    Member
    August 27, 2021 at 8:51 pm
    put it another way: the amount of heat energy in a given batch is governed by how much volume there is in that batch, and the material loss from that batch by evaporation is governed by how much of the batch’s surface area is open to the atmosphere

    assuming your batch is roughly hemispherical, as per standard reactor designs, then the volume is proportional to the radius of the vessel cubed, while the surface area exposed to the air proportional to the radius of the vessel squared; as the size of the vessel increases, the amount of surface area per unit volume decreases, and the so the amount of water loss decreases too

  • abdullah

    Member
    August 28, 2021 at 2:58 am

    @Bill_Toge thanks

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