Under what circumstances are the pre-tower and post-tower venting used in the ammonia synthesis process?
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Under what circumstances are the pre-tower and post-tower venting used in the ammonia synthesis process?
If the reaction is poor, the system pressure is high behind the tower; if there is a problem with the system, it’s ahead of the tower
Pressure relief for parking is generally done through the vent at the back of the tower, but care must be taken to prevent the ammonia solution in the tower from flowing back when using this vent； If the reaction does not proceed well, with a drop in temperature and an increase in pressure, venting is generally carried out at the front of the tower. However, when venting at the front of the tower, care must be taken not to open it too suddenly, to prevent the catalyst from being pushed back into the synthesis tower.
Venting in front of the tower for ammonia synthesis: This is hardly used in current operations, as it can cause the catalyst to clog the valves along with the airflow, making it difficult to control the furnace temperature. Usage of the vent behind the tower: 1. If the synthesis conditions deteriorate and the system experiences overpressure, the load can be reduced appropriately; if necessary, the vent valve behind the tower should be opened to relieve some of the pressure. 2. It is used during the initial startup of the system as well as during system purging and replacement. 3. It is used for pressure relief and load reduction during normal operation
Reply to 4# xnfh_wpzg: Thank you so much!
This post was last edited by Chemical Gas Purification on 2010-8-17 04:41. The pre-tower and post-tower venting are used to control the pressure difference in the synthesis tower during shutdown.
1. When trading in a car by driving it, both the front and rear compartments are needed. 2. When the system is depressurized, priority should be given to venting from the back; venting from the front is also possible, but not at a high rate, to prevent the catalyst from being displaced. 3. During normal operation, venting from the back should be used primarily for releasing methane. 4. When the system experiences excessive pressure due to deterioration, the total gas flow rate should be reduced, while simultaneously controlling the furnace temperature. 5. If the H/N ratio is high, it is also possible to open it and release the substance, so as to restore the temperament as quickly as possible
Reply to 4# xnfh_wpzg: If the methane level is slightly high, releasing it before opening the tower or after will result in a significant loss of ammonia