Process Description
Liquid ammonia is pumped from battery limits to the HP ammonia pump with a pressure of 26 kg/cm2 abs, and
temperature of 42 degrees C. To avoid vapour locking in this pump, the temperature of the ammonia should be at least
10 degrees C lower than the boiling point at the prevaling pressure. The flow to the synthesis section is regulated
by a flow controller of the HP ammonia pump. The pump has a discharge pressure of 160 kg/cm2 abs, and supplies
the ammonia to the HP carbamate condenser via the HP ejector.
The CO2 gas is supplied from the battery limits to a CO2 knock-out drum to separate the excess of water from CO2 gas.
This water is discharged from the knock-out drum to the sewer by means of the level controller. From the top of
the knock-out drum, the CO2 is led to the CO2 compressor to be compressed to 140 kg/cm2 abs., and introduced with
a temperature of 120 degree C into the bottom of the stripper.
Anti-corrosion air is added to the CO2 in the suction line by an air blower until an oxygen content of 0.75 - 1.0%
by volume is reached (registered by an analyzer-recorder in the first stage of the CO2 compressers).
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