8 May 2013:
Heat Transfer Fluids
As we have stated previously, we are going to be taking the ideas developed in this column over the last couple of years and developing them into design practices. This is how it works. We will provide the basic narrative here for one design practice each week. We will keep it open for comments for one month. After that, we will finish it in formal form and offer it for sale at a modest price. Here is where you come in. If you make a substantive contribution to a standard, the organization for which you work will be granted a pro bono license to use that standard with its current issue number for as long as you like. We have had good response so far! Contribute, please.
Heat Transfer Fluids (LGM 2013.018.01
For many years, steam has been used as the heat-transfer medium for paper machine dryers owing to its: non-toxic nature, stability, low costs and high heat capacity, with the greatest limitation coming in the form of the phase change that occurs at 100 degrees C.
However, over the years superior heat transfer fluids have been developed - the Dowtherm family of fluids being one such example.
To use alternate heat transfer fluids for paper machine dryers.
If one would consider using such fluids for dryer heating, all sorts of possibilities open up.
Dryers could be much lighter and really be a shell within a shell where the fluid only travels within the annulus between the two shells.
This fluid can be heated with a fire tube burner, no boiler needed. Also, no "condensate" loss, so no makeup water. The efficiencies go on and on.
As always, your comments will be appreciated.
Brian Brogdon, Ph.D.
Send us your comments by emailing Brian Brogdon
or Jim Thompson!