Question

Describe the engineering designs associated with vapor space above the tube bundle in a kettle reboiler and liquid levels above and below the tubes

Answer 1

Kettle reboilers:-

Basically Kettle Reboilers are a type of shell and tube heat exchanger whose motive is to produce two phase( vapor-liqud) mixture which return back to the distillation column.

Engineering design:

They have removable bundles of tubes which carry high temperature process medium such as steam. The fluid which is heated gets vaporised and start concentrating on the cavity space above the fluid. The remaining liquid moves down the weir and vapors return to the distillation column.

These Reboilers operate at a liquid level 2 inches above and 2 inches below the upper tube bundles. The velocity of vapors which exit the kettle reboilers must be low enough to avoid the situation of entrainment. The bottoms of the distillation column get spilled over the weir which in turn fixes the liquid level on the tube bundles.