As shown in the diagram: is it feasible for 2 methanol storage tanks connected at the bottom to share one set of nitrogen sealing?
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Is it feasible, as shown in the diagram, to use two methanol storage tanks connected at the bottom, which are connected via gas lines and share one nitrogen sealing system as well as one vent valve? What should be noted?
Methanol imports should be directed to the bottom feed; there’s no problem with using it in place of another substance. With the two tanks connected, it’s equivalent to having just one tank
1. The liquids should drop simultaneously, and the two tanks require the same amount of air supply. 2. The pressure control point is located in the left tank; once its pressure reaches the desired level, the pressure supply valve is closed, regardless of the pressure level in the right tank. The vapor equilibrium tube functions as a flow-limiting orifice plate; the pressure difference across it determines the flow rate that can be supplied to the right tank, thereby increasing its pressure. With high tank pressure, a larger pressure drop can be achieved on both sides, so the balance tube can be smaller. However, for micro-pressure nitrogen sealing, the diameter needs to be large.
Consider the possibility that one of the tanks might need to be taken offline during maintenance?
It is technically feasible, but the pressure drop in the pipeline must be very low; stricter requirements apply in the case of pipelines operating at atmospheric pressure, and the feed inlet needs to extend inward to the bottom of the tank. Consider what to do when maintaining a single tank; the most important thing is to be able to deal with the experts who conduct safety inspections later, as they will ask you various questions.
The pipe diameter must be large enough. The pipes should remain open at all times; there should be no valves or the valves should be locked, and proper management procedures must be in place
A customer reported unstable liquid levels in the storage tank; the company assigned me to investigate the issue. I found that the nitrogen level control valves were too large, so we shared two of these valves between them, and as a result the liquid levels became much more stable.
What are the effects of using a larger valve?