Please tell me, does liquid ammonia have to go through the buffer tank before entering the ammoniation kettle?
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I would like to ask everyone, there is a project now. The company directly passes the liquid ammonia into the ammoniation kettle through the pipeline (reaction temperature 90, pressure 60 kg) without passing through the buffer tank. Instead, when recovering the ammonia, it is cooled and recovered through the buffer tank. Is this reasonable? Thanks
Personally, I think it is necessary to set up a buffer tank. It is recommended to refer to the relevant design specifications, which should have relevant content.
According to the poster, "Pour liquid ammonia directly into the ammoniation kettle through the pipeline, (reaction temperature 90, pressure 60 kg) without passing through the buffer tank." That is to say, the ammonia participating in the reaction in the ammoniation kettle is still liquid. If a buffer tank is added in front of the kettle, its effect is only to stabilize the quantity, and has little effect on pressure and other effects! Therefore, if the diameter of the pipe in front of the kettle can meet the requirements of the process volume, there is no need to add a buffer tank!
I think this issue also needs to consider process requirements. If a buffer or pressure reducing valve is added, the liquid ammonia will turn into gas or the pressure will not be enough to affect the chemical reaction in the kettle. The process designer should be consulted. From a safety perspective alone, the lower the pressure, the better.
Liquid ammonia with a pressure of 60 kilograms must be pressurized by a pump. The amount of ammonia required for the ammoniation kettle is metered into the reaction kettle. I personally think there is no need to add a buffer tank in front of it. When recovering ammonia, cooling and recovering it through a buffer tank is mainly to balance the pressure in the kettle, so it is necessary.
It is best to go through the buffer tank, mainly to balance the pressure and increase the safety factor of the process.
The reaction pressure is 60 kilograms, while the normal liquid ammonia pressure is about 18 kilograms. It should be added through a pressure pump. Just like the high-pressure water in the boiler is also fed through a high-pressure pump. If it is pumped in, there is no need to add a buffer tank. One more piece of equipment and one leakage point, which is also detrimental to safety. The ammonia that is not completely reacted during the reaction is in gaseous state, so it is necessary to add a buffer tank to facilitate the recovery of liquid ammonia.
If a buffer tank is added and needs to be pressurized by a pump, then this tank will be a medium-pressure container, and the pressure will be higher than that of the reactor. This is unreasonable. It is also unsafe. There is no defined role for "buffer tank"!
From a safety perspective, a buffer tank should be added between the two.
Directly from the storage tank to the metering tank to the reactor, recovery requires adding a buffer tank and then to the ammonia compressor. A small ammonia compressor can be used from the tanker to the storage tank. Safe and reliable. please consider