Heating

[mayday31]

Hello,
So sorry for this very very stupid question concerning "heat transfer".

I have reactors jacketed with water for heating purpose. I want to have the temperature inside the reactors (closely tight, of course) at 40 degree Celcius. Will the room temperature (e.g. 35 degree Celcius) influence the heating activity?? (meaning that I cann't set the heater to be 40 degree Celcius)

Thank you very much in advance!!

 

[danw2]

Presumably your heating jacket contains water hotter than 40°C, otherwise your reactor contents will never get up to 40.

In answer to your question about the ambient room temperature affecting the heating, the heating jacket will lose heat to the room depending on its delta T over room temp and how well it is insulated to the room. But that only means that your heated water supply has to make up that heat loss.

Generally, one does not "set a heater". Rather one sets a setpoint on a controller which either turns heaters on or off or which controls how much replacement heated water is allowed to flow through the heater jacket.

 

[quark]

You will not have problems, if the heating media capacity is sufficient. Like dan suggested, insulation takes care of heat loss from jacket to room and thus you can save energy.

 

[wfn217]

Free convection losses will be around 1 BTU/(hr*ft^2*F). Radiation losses will be of a similar magnitude.