Why is a control valve used at the steam outlet of a reboiler to regulate the flow rate?
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Why is there a control valve at the reboiler’s outlet? Another point is that some reboilers are equipped with an expansion tank at their outlet; what is the reason for this?
The control valve is mainly used to regulate the flow rate of the heating medium and adjust the heat transfer amount. It can be installed at either the inlet or the outlet of the heating medium. The inlet flow can be controlled by installing a temperature control valve at the inlet ； Alternatively, a control valve can be installed on the outlet condensate to regulate the heat transfer rate by changing the liquid level of the steam and condensate in the reboiler. The expansion tank is a measure to recover some of the low-pressure steam.
This post was last edited by Catalyzing a Grain on 2018-8-25 at 11:02. If the temperature control valve is installed at the steam inlet, the condensation of steam inside the reboiler may, under certain conditions, lead to poor drainage of the condensate (for example, when the pressure at the steam inlet is low or the condensation efficiency is high). By installing the temperature control valve in the condensate pipeline, poor drainage of the condensate can be avoided.
I didn’t quite understand the question. In a reboiler, steam is usually used to control the flow rate at the inlet; after passing through the inlet control valve, the pressure drops significantly, which in turn lowers the temperature of the condensate water, thereby enabling maximum utilization of the sensible and latent heat of the steam. The device at the reboiler outlet is what we call a condensate tank; its function is to prevent steam from escaping and to drain water. There is usually no steam vent at the top; it is the saturated pressure at the condensate temperature, and it’s fine without one, but some do have one.