What precautions should new units take when introducing ammonia via pipelines?

(1) The system replacement is successful, ensuring that the oxygen level remains within acceptable limits and preventing explosions in the system； (2) Prevent low temperatures during ammonia introduction; if some equipment does not allow this, ammonia must be introduced under pressure ； (3) Strengthen personal protection, especially protection for the eyes.

For the ammonia introduction we are doing now, we first purge the ammonia tank with nitrogen, ensuring that the oxygen content meets the required standards. Furthermore, our ammonia tanks are at atmospheric pressure and cannot be pressurized; therefore, there are still many factors that prevent the normal introduction of ammonia.

Primarily, the replacement material must meet the requirements: the oxygen content analysis must be ≤0.5% before ammonia can be introduced.

1. The equipment replacement is successful, with O2 levels below 0.5%. 2. During the ammonia introduction process, the temperature is reduced gradually, while the amount of ammonia introduced is increased step by step. 3. Pay attention to controlling the pressure of the ammonia tank

A plan must be developed for introducing ammonia using a newly established unit, covering organization, coordination, provision of safety and fire-fighting equipment, emergency response plans, the extent of displacement, sampling locations, and precautions during the ammonia introduction process.

The main steps involve ensuring proper replacement, checking that there are no leaks in the equipment, then slowly introducing ammonia to establish a liquid level. At the same time, the vent valve is opened to maintain a certain pressure, after which the valves at the rear are closed.

Precautions for the ammonia introduction process: 1. First, perform nitrogen purging; ensure that the equipment meets the requirements with an O2 level of less than 0.5%. During the nitrogen purging process, be cautious of the risk of nitrogen asphyxiation, as this can lead to serious safety accidents. If new employees are not aware of the risks involved, it is important to share more cases of such accidents so that they can take it seriously. 2. Once the system has been properly purged with nitrogen, ammonia purification is carried out. Prevent low temperatures during ammonia introduction; if some equipment does not allow this, it is necessary to introduce ammonia under pressure ； However, attention must also be paid to the temperature at which ammonia is introduced; if the temperature is too low, the flashing rate of ammonia at such low temperatures becomes very slow, which can affect the progress of starting up the system. During the displacement process, make sure to carefully check that there are no leaks in any of the equipment; then introduce ammonia slowly to establish a liquid level. At the same time, open the vent valve to maintain a certain pressure, and close the valves at the rear end. Ammonia leaks are difficult to handle. 3. A plan must be developed for introducing ammonia using a newly established unit, covering organization, coordination, provision of safety and fire-fighting equipment, emergency response plans, the extent of displacement, sampling locations, and precautions during the ammonia introduction process. Enhance personal protection, especially protection for the eyes. In particular, the drills for emergency plans are not just theoretical; they must be carried out in actual situations to ensure the safe and smooth operation of driving.

Precautions for introducing ammonia: Proper preliminary preparations must be carried out before introducing ammonia. The equipment and pipelines need to be purged, replaced, and pressure-tested to check for leaks; in particular, the pressure-testing and leak-checking procedures are crucial and must be carried out thoroughly, ensuring no gaps remain, including at sealing areas such as valve flanges. A proper plan for introducing ammonia must be developed, and personnel must receive adequate training to ensure they can perform their tasks skillfully. There should be dedicated personnel in charge, as well as emergency response plans. Before introducing ammonia, all valves must be checked carefully – those that need to be opened should be opened, and those that need to be closed should be closed. Vacuuming must be completed successfully before ammonia can be introduced.

I have a question regarding ammonia introduction later: after the refrigeration system has been properly purged with nitrogen and ammonia is introduced into the system, can the natural evaporation of ammonia, without turning on the ice maker, remove all the nitrogen from the system? Is it possible to reduce the nitrogen content in the system to less than 1%?