Vacuum breakdown issue in Class A reactors
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For a project design, manufacturers of Class A reactors require vacuum to be broken by introducing air directly. Is such a practice permitted according to the operating standards? Personally, I think using nitrogen to break the vacuum is safer. Additionally, if atmospheric air is used to break the vacuum, is it necessary to install a flame arrester?
Breaking the vacuum in this way is definitely not proper; once air gets in, it creates explosive gases, and if there is static electricity or something similar present, it can be very dangerous. The vacuum equipment here all uses nitrogen to break the vacuum.
How do we calculate the amount of nitrogen needed? Our setup also requires vacuum breakdown, and we just don’t know how much nitrogen is required.
Are there any regulatory provisions that would make it easier to persuade the industry?
In such a case, it is necessary to address the reason for the vacuum forming inside the reactor – could introducing air pose a danger? Generally, steam and nitrogen are commonly used in industry. (I hope we can communicate more and learn together in the future; QQ: 75658313)
It mainly depends on the medium inside the reactor; if flammable or explosive media are involved, nitrogen or steam is generally used to break the vacuum. Pipes that break the vacuum do not require flame arrestors, as any combustion or explosion occurs inside the reactor.
Design must follow principles; as for the owner’s implementation, that is his concern.
Class A liquids that are not volatile should be fine, right?
Our vacuum equipment is equipped with a pressure gauge, usually a negative pressure gauge; when filling it with nitrogen or steam, it’s sufficient to see the pressure gauge return to zero at negative pressure. If it’s a gauge that shows both positive and negative pressures, things are even more straightforward – just pressurize it until the reading moves slightly in the positive direction from zero. Slow down the inflation speed; do not inflate too quickly. Do not leave the area unattended to prevent overpressure from causing the safety valve of the equipment to blow off or cracking the flange gaskets.
Is this also part of the standards? Since it is a Class A medium, once air gets into it, calculate whether it falls within the explosive range. If it is within that range, then it is unsafe; does one still need to follow relevant standards when dealing with an explosive situation? The owner isn’t a fool. . The key is that you need to present data, not standards!
Thank you for the guidance; it was a great help to me:handshake:handshake