How to replace ammonia in the system when the ammonia compressor is initially started?
Thread Content
For the low-temperature methanol washing and purification process, during the initial start-up preparation of the ammonia compressor unit, the nitrogen in the unit system must be replaced with ammonia to be qualified. The ammonia content must be greater than 90% to be considered qualified! But how to replace it in practice? Generally, during ammonia replacement, the low-temperature methanol washing system has not yet established a cycle. Directly passing ammonia into each ammonia cooler is not good for the equipment, and there is not much pressure difference from the liquid ammonia storage tank to each ammonia cooler. How long does it take to replace the nitrogen in the system by natural volatilization? ? If the compressor is turned on directly and the nitrogen in the system is replaced, the outlet pressure will not be able to hold it anymore before the rotation speed rises to the normal value, and it needs to be vented and replaced. This will cause a large amount of ammonia loss and a huge waste of resources! @ Please actively discuss how to do it quickly and easily with less resource loss?
This is mainly because the presence of a large amount of non-condensable gas - nitrogen, will affect the operation of the ammonia condenser, affect the heat exchange effect, lead to high compressor outlet pressure, and even interlock action
When the ammonia compressor is initially started, the entire equipment is at normal temperature. First, introduce liquid ammonia into the liquid ammonia storage tank and open up the liquid ammonia pipeline process. The liquid ammonia will quickly vaporize and the pressure will increase, and the liquid ammonia will enter each ammonia cooler through the liquid ammonia pipeline to vaporize. This is just a matter of opening the compressor vent valve for vent replacement. Another point is to close the valve between the compressor outlet and the water cooler. This will create a pressure difference. Connecting the gas phase of the ammonia cooler when the compressor is running can speed up the replacement.
Our factory's ammonia compressor did not use nitrogen replacement when it was originally started. After the lean gas replaced the air, ammonia was directly introduced, and liquid ammonia was vaporized to replace the lean gas!
What is lean gas? How do you replace it?
We have an oil boiler. You can now establish the liquid level in the oil boiler. Once heated, a large amount of propylene gas will be produced, so it can be replaced!