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Thread: Help Me

  1. #1
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    Help Me



    How to design a heat pump dehumidifer for tobacco curing with capacity of the romm is 20 x 15 x 4 m.
    The outside design is 25oC and 75% RH....and the inside design room for tobacco curing is 40oC and 60% RH...please also include the psychrometric chart



  2. #2
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    Re: Help Me

    why not just add in a bunch of dehumidifyers?

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    Re: Help Me

    Quote Originally Posted by hery
    How to design a heat pump dehumidifer for tobacco curing with capacity of the romm is 20 x 15 x 4 m.
    The outside design is 25oC and 75% RH....and the inside design room for tobacco curing is 40oC and 60% RH...please also include the psychrometric chart
    From the data you have posted it would appear that you require a dehumidifier and a reheater to achieve your 'in box conditions'

    15K temp increase and 15% humidity decrease.

    Are there any specialists in your area that can help?

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    Re: Help Me

    Hi Hery
    Tobacco air circulation pass evaporator and heating fin-tube heat exchanger ,and the air temp increase and humidity is decrease. The issue needed attention is the condenser split into two parts: inside part for heating air and outside condenser and related heat capacity adjustment component.
    The system capacity depends on how to balance the drying time and the initial cost.

    only for your reference

    regards
    LC
    I hear...I forget;I see...I remember;I do...I understand

  5. #5
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    Re: Help Me

    Lc, you can also use another gas so that you can install the condensor inside so that the machine can run on a higher indoor temperature.
    We've buikd some 15 years ago on r114a as far as I can remember (wood drying) Inside temperature +/- 55°C.
    How will the tobacco stacked in the room? You need a very good air circulation around your prodcuts, apart from the dehumidifier.

    I think you can find a lot of information in this link http://pubs.caes.uga.edu/caespubs/ES-pubs/RB439.htm

    http://www.bulk-online.com/Forum/sho...?threadid=4986
    It's better to keep your mouth shut and give the impression that you're stupid than to open it and remove all doubt.

  6. #6
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    Re: Help Me

    Peter,

    Do you have a flow diagram of the heat pump you built for the wood drying? I'm trying to understand how this process works of drying applications.

    Thanks also for posting the link on the tobacco curing. It is very informative.

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    Re: Help Me

    Just noted now you message USIceman.
    For some reason, I didn't receive a mail that there was a new post.
    The setup is really basic as you can see.
    The R114 was to avoid excessive HP but this did you know.
    Attached Files Attached Files
    It's better to keep your mouth shut and give the impression that you're stupid than to open it and remove all doubt.

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    Re: Help Me

    Hery,

    Based on the data you provided, you should add moisture to the air. At 25 degree C and RH=75%, the humility rate is 0.015 kg/kg. At 40 degree C and RH=60%, the humility rate is 0.02855kg/kg. So you need to add 13.55 gram water per 1 kg dry air.

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    Re: Help Me

    Peter,

    Thanks for the diagrams. It was just as I expected. Nothing too fancy, very simple.

    Was there anything specific you ordered for the fan motors? Perhaps heavier motor insulation rating for higher temperatures?

    Thanks for sharing the information Peter.

  10. #10
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    Re: Help Me

    Hery,

    Here is the process in psychrometric chart, wmf format.
    You need add water like vincent yu said.

    autt
    Attached Files Attached Files
    Last edited by autt; 22-08-2006 at 04:18 PM.

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