1 reply to this topic

[renjith553]

Hi,

 

I need to size the external limpet coil for keeping my storage tank( 10m height X 3 m dia) at 25-30 deg C.. I will be passing hot water at 40-45 deg C through the coil to heat up the content in tank from 15 deg C to 25 deg C.. Do I need to calculate the limpet coil heat transfer area in contact with the tank or is there a thump rule which mentions what should be the pitch and dia of the limpet coil based on the size of the tank..  I just need some advice in how to proceed with ..  

 

 

Regards,

Renjith.. 

[Art Montemayor]

 

 

Renjith:

 

Why do you want to use a very inefficient way of heating a storage tank – such as a limpet coil (which is a half-pipe welded around the external surface of a vessel in a spiral configuration?  A “pan cake” type of internal coil is usually what is used in heating the contents of storage tanks.  This method is more efficient and much, much less expensive.

 

There are no “thump” rules.  There are rules of thumb – but none that I know of for designing and sizing a limpet coil.  If you are trying to heat up the internal fluid then you reduce the pitch of the coil as much as you practically can – which is the distance sufficient to weld the half-pipe to the vessel wall.  As I have stated, this is a very inefficient design and you want to maximize the available heat transfer area as much as possible.

 

Refer to the following past thread on this topic and to the attached: http://www.cheresour...t-coil-problem/

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