Does dimethyl ether spherical tank need nitrogen sealing?
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Due to the high saturated vapor pressure of dimethyl ether at room temperature, it is generally stored under pressure (pressure is 0.8MPa). When the pump delivers dimethyl ether liquid to the spherical tank, is it necessary to install a gas discharge valve on the top of the tank to prevent the pressure inside the tank from being too high? ； When the pump transports the dimethyl ether liquid in the spherical tank to the tanker, is it necessary to set a gas input valve on the top of the tank to prevent the tank from being collapsed? ； Therefore, whether nitrogen pipelines need to be considered on the top of the tank.
It should be considered that it is beneficial to reduce pressure fluctuations in the storage tank, especially when the tank is smaller and the filling speed is faster.
If there is no need, just add a gas phase balance pipe to the spherical tank. It needs to be replaced with nitrogen before being put into use. During use, non-condensable gases will gradually increase. To prevent overpressure, water should be poured outside to cool down in summer.
Dimethyl ether is a liquefied hydrocarbon, right? It cannot be stored under pressure without a drain valve, breathing valve, etc. Instead, it is connected to a gas phase balance pipe to achieve pressure balance during material transportation. The storage tank must have a safety valve!
The dimethyl ether storage tank is a spherical tank, which is of the same nature as the liquefied balloon tank. If it is equipped with a nitrogen seal, can it be sealed by the pressure of nitrogen? What is the purpose of nitrogen sealing? The operating pressure of the dimethyl ether spherical tank is above 0.4MPa, and the outside air cannot enter the spherical tank at all! The poster said that he was afraid that the spherical tank would be deflated. Haha, with the high vapor pressure of dimethyl ether, it is natural for the liquid level in the spherical tank to drop when the dimethyl ether liquid material is pumped out. Due to the high vapor pressure and strong volatility of dimethyl ether, the dimethyl ether vapor will gradually evaporate. The small amount of vaporization of dimethyl ether will absorb heat. The temperature of the liquid dimethyl ether in the spherical tank will drop a little, and the corresponding vapor pressure at this temperature will also drop a little, eventually establishing a new gas-liquid balance. You will understand this by looking at the PT curve of dimethyl ether. Even if you pump out all the dimethyl ether liquid in the spherical tank, the dimethyl ether vapor in the spherical tank will always exist, and the spherical tank will never be deflated. If you want to repair this spherical tank, you will eventually need to pump out the residual dimethyl ether vapor in the spherical tank or set off the flare system. After setting off the flare, when the pressure of the last remaining dimethyl ether vapor is less than the entry pressure of the flare system, nitrogen needs to be replaced and blown out, and the nitrogen pressure will continue to be sent to the flare. The correct answer is: Nitrogen sealing is strictly prohibited. It is a serious mistake to set up nitrogen sealing. This post was last edited by 1681818 on 2008-3-16 11:44 ]
The correct answer is that the poster should read more books. This question is a bit unprofessional.