Function of steam control valve in Vaporizer
Function of steam control valve in Vaporizer
(OP)
Folks,
Does anyone knows that in a Reboiler system (e.g. stabilizer bottom, vaporizer), sometime we use a valve to control Steam pressure at inlet & sometime we use a valve to control the condensate flow at the outlet. What is the main reason behind this and which one is more effective? Moreover, what would be the relation between steam pressure and heat exchange in the system?
Actually I am optimizing the heat flow in a vertical shell and tube heat exchanger/Vaporizer. We have steam at tube side and hydrocarbons at shell side.
Your responses will be highly appreciated :).
Does anyone knows that in a Reboiler system (e.g. stabilizer bottom, vaporizer), sometime we use a valve to control Steam pressure at inlet & sometime we use a valve to control the condensate flow at the outlet. What is the main reason behind this and which one is more effective? Moreover, what would be the relation between steam pressure and heat exchange in the system?
Actually I am optimizing the heat flow in a vertical shell and tube heat exchanger/Vaporizer. We have steam at tube side and hydrocarbons at shell side.
Your responses will be highly appreciated :).





RE: Function of steam control valve in Vaporizer
A steam control valve varies the steam pressure in the exchanger and therefore the condensation temperature and dT to match the exchanger capacity to what the process needs. You still need some way to control the condensate out, either steam traps or more commonly another control valve controlling the level in a condensate pot. I don't see many steam traps on refinery steam exchangers but there are some.
Adjusting the steam pressure gives you faster control in my opinion than flooding or unflooding reboiler tubes. A vertical thermosyphon, if you are going to flood tubes, is a good choice because the same percentage change in condensate level = a similar change in heat transfer area. For a horizontal reboiler, that's no true. Near the bottom of the tube bundle you may not be covering or uncovering many tubes for a change in level. At the mid point, you are covering or uncovering proportional a much greater area for the same change in condensate level.
RE: Function of steam control valve in Vaporizer
Dejan IVANOVIC
Process Engineer, MSChE
RE: Function of steam control valve in Vaporizer