How to quickly remove liquid ammonia?
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I would like to ask the experts here: at our plant, liquid ammonia is currently unloaded by connecting a flexible metal hose to the quick connector on the liquid ammonia tank truck, and then it is pumped into the liquid ammonia storage tank using a liquid ammonia pump. It takes nearly three to four hours to unload 30 tons of liquid ammonia. Is there any safe and effective way to quickly unload the liquid ammonia? Thank you! ! !
Pressurized inert gas (such as synthetic purge gas) is used to force liquid ammonia out of the tank truck; this method is faster. However, the problem is that after the discharge, the concentration of inert gas in the tank truck becomes too high, and when it is refilled, this gas is released into the ammonia vapor system, which increases the load on the refrigeration unit. Actually, using an ammonia pump is a good method; if it seems too slow, one can consider modifying the pipelines and the pump.
:Lol, just increase the diameter of the delivery pipes! Three-inch and two-inch hoses will do!
The method on the third floor seems like a crude approach, but it is indeed a practical one. We discharge liquid ammonia more slowly – at a rate of only about 5 tons per hour. Now, we prepare the empty storage tank in advance, release the pressure inside it, and then enlarge the pipelines as well; this results in a much faster flow rate.
Today, liquid ammonia is unloaded using ammonia compressors; it takes 80 minutes to unload a 30-ton tank truck, which is both safe and fast!
What should be done with the ammonia remaining after unloading it? Could it pose a hazard to the operators?
There is currently no good way to quickly remove liquid ammonia. :sleepy:
Using an ammonia compressor, how to operate it specifically
The delivery pipeline has the same size as the inlet and outlet pipes of the ammonia pump; if it were larger, it wouldn’t make any sense. Theoretically, it could even increase the amount of gasification, which isn’t good
The liquid ammonia flow rate at the tank truck outlet is also subject to interlock protection; therefore, unloading cannot be carried out too quickly either. Our factory uses ammonia tanks to release pressure and obtain liquid ammonia, which is then directly fed into the system for use.
Both using an ammonia pump and a compressor to apply gas-phase pressure is feasible; the operation is also crucial. There must be a pressure difference between the storage tank and the tank truck, otherwise unloading will definitely be slow. If the pressure in the storage tank is high, it is necessary to vent gas to reduce the pressure. If the gas can directly enter the application process, then there is no problem; however, if liquid ammonia is purchased and used directly, it needs to be pressurized and cooled before being reused.
Using medium-pressure nitrogen to liquefy ammonia makes unloading convenient and fast.
When unloading ammonia tankers, in addition to having a sufficient pressure difference, it is also necessary to take into account the pressure exerted by the ammonia tank. Because if the pressure difference is too large, some of the liquid ammonia reaching the receiving tank will inevitably vaporize, resulting in losses. However, if the pressure difference is low, it will result in slow unloading.
Increase the pressure in the tank truck and reduce the pressure in the ammonia tank; the greater the pressure difference, the shorter the time required, and the resulting vent gas can simply be burned off
Feed the tank truck with the vent gas from the liquid ammonia storage tank； Pressurize the tank truck ； The speed can be increased
We just use ammonia gas......................
Under pressure: The ammonia gas in the tank is pumped out using a compressor and pressurized before being fed into the tank truck, thus creating a cycle
The compressor draws ammonia out of the tank to pressurize the tank truck; liquid ammonia is then forced into the tank through internal circulation