Precautions for operating a reboiler
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I read in the documentation that the vapor fraction reboiler must not be empty nor full when in operation, otherwise siphoning cannot occur – is that true? Please ask an expert to speak; there will be a generous reward.
Reboilers are divided into siphon type and kettle type; the kettle type functions like a single tray, while the siphon type relies on density differences to enable circulation. What you mentioned about the siphon reboiler not being able to be filled to capacity likely refers to its shell section. Generally, there is no control over the liquid level in this shell section. When there is no heat source in the tube section, the shell section is definitely filled with liquid. When a heat source is present in the tube section and the temperature reaches the vaporization point of the liquid, the vapor accumulates at the top of the shell section and enters the tower through the vapor return line of the reboiler. At this point, the space vacated by the vapor in the reboiler is once again filled with vapor. (Heating is a continuous process.) Since the density of vapor is lower than that of liquid, a density difference is created between the upper and lower parts of the reboiler’s shell section, allowing the vapor to rise continuously while the liquid at the bottom continuously replenishes it, thus creating a cycle.
The liquid level in the reboiler bottom cannot be either empty or full; if it is full, it can easily block the return port, resulting in poor thermosiphon effect and affecting the heat exchange efficiency of the reboiler. An empty liquid level in the bottom of the tower can cause the liquid and gas in the reboiler to evaporate. Once it has evaporated, any additional liquefied gas that enters the reboiler will instantly vaporize, leading to a surge of gas that disrupts the operation of the entire tower.