Tank Heating

[PracticalEngr]

Hello All:
I have a cooling tank which is used to cool higher chain hydrocarbons from 400 Deg C to around 250 Deg C. To avoid material solidification inside the tank there is an immersion heater but the heating is only accomplished up to level of the heater. To avoid material solidification at the bottom of the tank; I'm thinking of wrapping mineral insulated cable on the bottom to provide heat.
Any thoughts or recommendations over using MI cable? any other advice based on prior experience
Regards,
PracticalEngr

 

[LittleInch]

Normally you would add a mixer or similar to keep the temperature uniform throughout the tank.

Heat trace cable in a liquid ( I assume you mean just lay it on top of the tank material) doesn't sound a like a good idea to me, but you might need to explain this a bit better.

What is the under bottom insulation?

Laying cables under the tank floor would allow the heat to be much more spread out rather than the localized heating you would get from a cable.

A few more drawing or data would help.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Compositepro]

Place a sheet metal baffle around the heater inside the tank. The baffle can form a chimney around the heater with a gap of a couple inches from the tank floor. That way hot fluid rising from the heater will draw-in cold fluid from the tank floor.

 

[gerhardl]

The construction I have seen (although for lower temperatures) is tanks with mixer and a combined outer shell (or envolving spiral) for heating steam and cooling water (one or the other alternatively).

For this higher temperature steam would probably give a too demanding pressure, but outer el. heating and mixer inside seems right, plus insulation (rockwool type) seems sensible. How do you cool?

PS.I have seen a tank with solidification, luckily not caused by my operation. Took a week by manual cleaning to get back in operation.