speed diathermic oil

[marcoci]

Good morning.
I have been looking on the net for a few days more information about the sizing of pipes for diathermic oil plants. I found several tables, publications and articles with the calculation of load losses, diameter calculations etc. that depend (clearly) always on the flow and therefore on the speed.
the data to be fixed a priori is therefore the speed:

1. I am well that the speed in boiler gives the builder, but the speed for example in an oil/smoke heat exchanger (where the fumes give heat...) will be like that in boiler?
2. what speed I choose for the connection pipes between the exchanger (oil/fume) and user, for example, an evaporator, an oil/water exchanger or an orc?

I read somewhere 0.5-0,7m/s, is a "believable" value since the above tables also reach 8m/s?

 

[paulpaul]

Usually for liquids a discreet compromise between load losses and tube size is about 0.5-1,5 m/s, quite independently from the application. for gas between 10 and 20 m/s.
then obviously there are exceptions, but the above data are good technique and I would start from those.

 

[marcoci]

Thanks for the answer.
I'm looking literature, articles, publications anything where you can find an indication of speed or load losses per meter: for all other thermovector fluids (or other energy carriers) there are dozens, for diathermic oil I found nothing.

However after an afternoon I came to the conclusion that since the specific oil used (mobiltherm 605) at the expected working temperature (300°c) has almost the same characteristics of water viscosity I will calculate the pipes as if they transported water taking into account load losses in the order of 250pa/m (and the speed that will come accordingly).

 

[paulpaul]

calculate them with the usual fluidodynamic formulas (by hand or with dedicated programs): you need "only" oil density and viscosity data at the temperature you need, but I think that by contacting the manufacturer you can receive them.

 

[marcoci]

You are right, I just think that unlike other carriers there is no literature or publications about it.
Thank you.