Liquid level issues in the gas-liquid separation tank
Thread Content
Generally speaking, if some of the gases in the mixture are to be separated by condensation and cooling, a certain liquid level must be maintained in the separation tank or buffer tank. So, may I ask, what is the principle behind maintaining a certain liquid level? ? Is it related to the saturated vapor pressure? ? ? So are there any requirements regarding the gas pressure in the upper part of the separation tank or buffer tank? ? ? What is the principle? ? ?
If the gas phase pressure is relatively high, this liquid level serves primarily as a liquid seal to prevent gas from passing through the bottom when the liquid level is too low and reaching the next processing stage; if pumping is used at low pressure, the liquid level only needs to meet the requirements for pump operation.
2# su*ubin – Is it only related to the liquid seal? ? No impact on the gas-liquid separation efficiency? ? ? Does the saturated vapor pressure have no effect? ? ?
The principle of the gas-liquid separation tank is natural sedimentation, which has nothing to do with saturated vapor pressure or gas pressure. The appropriate level for liquid level control depends on the purpose of the tank itself. For example, in the reflux tank at the top of a tower, it is generally necessary to ensure a reflux time of 15 minutes or a product extraction time of 3 minutes. The minimum liquid level should be at least 3 times the diameter of the outlet pipe (mainly to prevent vortex formation), and it must not be less than 300 mm. But for other tanks, such as the compressor feed buffer tank, it is generally sufficient to ensure separation of gas and liquid (that is, there will be no liquid carried along due to too high a liquid level, nor will there be gas leakage due to too low a liquid level).
For the enterprise separation tank used for mixed gases, first, under the operating conditions applicable to you, it is necessary to liquefy one or several of the target gases; once liquefied, these gases remain in a saturated state within the separation tank, achieving a state of equilibrium； Second, maintaining liquid level balance ensures that the mixed gas remains in this balanced state once it enters the tank, thereby achieving separation ； Third, due to the continuous liquefaction of gas, it is necessary to control the liquid level to ensure the proper operation of the separation tank. Actually, what was said above is already clear enough; I hope the original poster can provide more details, and once each stage of change in the mixed gas is explained, it will become understandable.
If the liquid level is controlled too high, gas will carry liquid with it; if there is no risk of high pressure pushing its way into low pressure areas, then a liquid seal is not necessary. The lower the liquid level, the better
The maximum liquid level will not exceed the feed inlet, and the level of the liquid has no impact on gas-liquid separation
I’ve learned something; thank you all! ! !
The 2nd, 4th, and 5th floors were well described. Thank you, I’ve learned it