System startup --- Ammonia injection
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There is an ammonia flushing step when the system is started up, right? It’s ammonia flushing, isn’t it? Why flush with ammonia? What is the function of ammonia flushing? Thank you
This post was last edited by Green Grass Walk on 2010-4-4 20:24. It’s about filling with ammonia, right? The system must be filled with ammonia before catalytic reduction to prevent freezing and blockage caused by the water generated in the early stages of reduction. During the catalytic reduction process, controlling the water vapor concentration of the gas entering the reactor is a key factor. To control this concentration, it is necessary to reduce the temperature after ammonia cooling as much as possible. To prevent water from freezing during reduction, ammonia must be added to the system before reduction to form ammonia water, thereby lowering the freezing point of water and ensuring the desired inlet water vapor concentration.
It can also prevent water from freezing inside the ammonia cooler, thereby avoiding blockages in it.
So, is the ammonia to be charged into the ammonia cooler, not into the system or the synthesis tower? Where does the ammonia water that is produced go? Is there no harm? 2# Green Lawn Stroll
Ammonia charging is generally done using a positive displacement pump to inject liquid ammonia into the process pipeline before it reaches the synthetic water cooler
Before starting up the ammonia synthesis system, ammonia is generally transferred from the ammonia tank to the ammonia separator through an ammonia release valve. Afterwards, feed gas is introduced into the system and the circulation pump is used to initiate circulation, so that almost all of the ammonia introduced into the system evaporates into the gas undergoing heating and reduction. The ammonium water generated during this heating and reduction process is discharged into the ammonium water tank when its concentration is low; once the ammonia concentration becomes high toward the end of this process, it can be discharged back into the ammonia tank.
What was discussed earlier concerns the nitrogen filling in the synthesis section; during startup, the system is generally protected or activated by using nitrogen. Nitrogen protection: Utilizing nitrogen, an inert gas, helps to protect equipment and pipelines from corrosion caused by humid air. Another portion of nitrogen filling is intended for processes that use compressors, which require starting under pressure; therefore, nitrogen filling is necessary ； Additionally, nitrogen can displace the air in the system, preventing combustible gases such as natural gas from mixing with air and causing an explosion.
1# Basketball Tribe: Ammonia is introduced into the system only in advance when the new catalyst has reached a stable reduced state. The purpose is to prevent the water generated from freezing at low temperatures and blocking the pipes. This phenomenon can be avoided by generating ammonia solution after charging ammonia. Ammonia charging is not required when driving normally