Who has done nitrogen sealing with ammonia?

Should the ammonia tank be a fixed-roof tank? The nitrogen sealing design can be implemented by referring to similar methods; there is nothing special about it. But is it necessary to add a nitrogen seal?

20% ammonia solution; I asked many colleagues, and none of them use nitrogen sealing – it’s a requirement specified in the owner’s technical specifications. There is a problem: isn’t the nitrogen seal meant to be used in conjunction with a breathing valve? Can a breathing valve that contains a mixture of ammonia and nitrogen simply be used to vent that mixture? Additionally, I would like to make this breather valve activate infrequently; that is, during material feeding, the set value of the breather valve should be much higher than 2 kPa, so that the nitrogen inside remains compressed and the valve does not activate. Is that possible? Because the storage tank is actually used as a pressure storage tank, with a design pressure of 0.5 MPa

Although I’ve never done any design work, I can offer you some suggestions. 1. Discharging ammonia directly is not only unsustainable (given the currently severe environmental challenges) but also unsafe. 2. The pressure of the breather valve is much higher than 2 KPa, which will result in poor feeding. It’s too complicated to design the storage tank in this way; why not add an absorption tower? Eco-friendly and safe

1. Ammonia nitrogen sealing is used to create a vacuum inside the tank during discharge, thereby replenishing pressure and preventing air from entering and reaching the explosive limit. 2. When ammonia water is added, the positive pressure generated in the storage tank causes the water seal tank to absorb the ammonia gas and release it into the atmosphere

1) First of all, in accordance with current environmental regulations, ammonia definitely cannot be released directly into the atmosphere. So whether nitrogen sealing is used or not, it is a dome tank. A vent valve is required; it does not release gas under normal conditions and only opens when needed. This has little impact on whether a nitrogen seal is installed or not. Nitrogen sealing is primarily used as a gas replenishment measure, employing an inert gas to isolate air and reduce its entry. 2) The set pressure of the breather valve depends on the design pressure of the storage tank. Generally speaking, the large tanks I have come across do not have a design pressure of 0.5 Mpa; those are already full-scale pressure spherical tanks. Generally, it’s not very suitable, unless the tank capacity is extremely small. 3) Once the design pressure of the storage tank is increased, it leads to higher investment costs for the tank. It is possible to reduce the number of times the vent valve (safety valve) needs to be activated, but this approach is not very economical and is therefore not recommended.