The issue of maintaining a vacuum
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The device is very simple: it consists of an air storage tank, an inlet, and an outlet. Import air pressure: 10 barA, flow rate: 500 Nm3/h. A vacuum pump needs to be installed at the outlet now to maintain the tank pressure at 50 kpaA. Personally, I think it is necessary to add at least one valve at the inlet of the storage tank, using this valve to reduce pressure. Otherwise, no vacuum pump can achieve a pressure of 50 KpaA.
This pressure reducing valve is difficult to configure, as the pressure on the primary side of a typical air pressure reducing valve is usually around 0.7 MPaG, while the pressure on the secondary side ranges from 0.2 to 0.4 MPaG; one valve may not be sufficient in such cases. 2 is better. If only one valve is used, it’s very likely that the pressure behind that valve will reach sonic levels, and the noise generated in such a situation is extremely loud. It is recommended to consult manufacturers specialized in producing air pressure reducing valves to see if there are any adjustments that can be made to the process. If the medium involved is just air, then it might be possible to find a point in the process where the air can be released first (for example, using a vacuum pump to extract the air and discharge it directly) It is better to evacuate again, as this will significantly reduce both the pumping capacity of the vacuum pump and its energy consumption.
Why can’t a pressure of 50 kPa(a) be achieved? Your use of valves doesn’t enable the system to achieve this pressure……
Do you mean to start the vacuum pump first, and then introduce air once the pressure reaches 50kpaA? It seems impossible to control the stress this way.
What about adding another high-pressure tank in front of this one? I’m not sure if that’s feasible; pressure could be adjusted at the inlet of the high-pressure tank.
That’s not what I meant. What I’m asking is whether it’s possible to empty the tank to a slight positive pressure before evacuating it.
Without a pressure relief valve, it is very difficult to reduce the pressure in the tank to a slight positive pressure.
OP, with such a large difference in pressure before and after, it should be possible to vent the system using the current setup before allowing fluid to enter the tank, thereby reducing the pressure appropriately; otherwise, you’ll need to install many pressure regulators. Can’t empty a portion first? Do you still need to use your gas? It wasn’t explained clearly