What is the purpose of the restrictor orifice plate at the reboiler? ?
Thread Content
The younger brother encountered some doubts and couldn't figure it out no matter how hard he tried. We have a vacuum tower here, and the column kettle is a forced reboiler, but there is a flow-limiting orifice plate at the outlet of the reboiler, and the bypass of the orifice plate is a stop valve. It should limit the vaporization of materials. Because the tower kettle contains some heavy components, I personally think it is because the boiling point of the tower kettle material is high, so it is necessary to have such a flow-limiting orifice plate to form a reduced pressure reboiling, and finally allow the tower kettle material to vaporize? ? Also, for other towers, which are also vacuum towers, the reboiler of the column kettle also has a flow-limiting orifice plate, which is installed at the inlet of the reboiler and also has a bypass valve. I think this is purely to limit the flow into the reboiler. Although both are in the reboiler, the functions of the two flow-limiting orifice plates should be different. Because the upper one has been heated, there is a possibility of vaporization, while the lower one has not been heated, it is just a pressurized flow restriction. I don’t know if I understand it correctly, and I hope experts can give me some pointers.
The original poster is right. The first one is to increase the pressure in the reboiler to prevent the material from vaporizing and make the heat exchange effect better. Due to the presence of heavy components, vaporization in some locations may cause coking. The restriction hole is in the front, which should limit the flow. If a pump is used for forced circulation, it may also protect the pump.
The flow-restricting orifice plate is in the front to prevent the regulating valve from malfunctioning and causing loss of control.
What the person on the 2nd floor said is correct and answered the original poster’s question very well.
That's it. Thank you everyone.
The analysis on the 5th floor was very thorough, answered the main question and solved my doubts.
Only the vacuum tower has such a setting. I think it is meant to limit excessive vaporization, just like the flow-limiting orifice plates used in the two catalytic cracking units to prevent excess gas phase from being generated due to excessive pressure. Mainly to maintain the vacuum in the tower.
If it is according to what you said, then all reboilers should be equipped with flow-limiting orifice plates, but why only forced circulation reboilers have flow-limiting orifice plates?