LuckyWinner - 3-6-2021 at 14:27
I have a small jacketed flask,
which I want to use to do a reaction which needs cooling -10C and heating +130c.
'professional' hoses which are used in combination with recirculating chillers
are usually made out of Flexible stainless steel tubing, insulated with fiberglass and silicone. Temperature Range -80 to 200°C
or occasionally
Material: PTFE,
Temperature range: -30 - 260 °C
PFA, a PTFE clone, would also be an option and a bonus since its more flexible then PTFE.
could you buy some PTFE,PFA or regular silicone tubing and slide some silicone foam tubing over it to achieve a similar insulation then the expensive
commercial hoses?
for cooling/heating liquid the options are: mineral oil... which apparently turns yellow after a while ...
or the proper mixture of x% ethylene glycol and x% water ?
Endo - 3-6-2021 at 14:33
To hit the final question in your list here is a great resource.
https://www.engineeringtoolbox.com/ethylene-glycol-d_146.htm...
The ratio of glycol to water is going to be very high to prevent boiling at the upper temperature you are looking for. ~90%
Belowzero - 3-6-2021 at 14:43
I can't answer the part about tubing, I just use rubber and hope for the best, sometimes wrapped in aluminium foil.
I have a cooling/heating bath and I use propyleneglycol as a medium , undilluted this allows me to go up to ~150-160 degrees C, and as low as ~-35
(thats really pushing it and it depends on the ambient temp, it supports up to -30 and starts draining power like there is no tomorrow).
When I need higher temp I generally use another waterbath.
Ethylene glycol needs quite a high percentage of water to lower its freezing point but it also limits its boiling point, a quick search didnt turn up
any quick digits but I think its either one or the other.
Perhaps more complex mixtures will allow for a wider range or perhaps cheap mineral oils (baby oil anyone?)
[Edited on 3-6-2021 by Belowzero]
LuckyWinner - 3-6-2021 at 19:02
why does nobody use silicone tubing in the commercial hose products?
I know silicone tubing cant be used with silicone oil but if you use propylene/ethylene glycol it should withstand that.
Silicone rubber, unlike the majority of other rubbers, can withstand extreme temperatures way above 200°C and down to as low as -60°C without
deforming
simply take the silicone tubing, wrap it inside a silicone foam or other insulating material and thats the perfect flexible
cooling/heating hose?