Main cold pour
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Dear friends, I would like to ask you a question. What are the dangers of back-filling the main cold water? Back-filling the main cold water will cause the accumulation of hydrocarbons and may cause severe stretching of the pipeline. What other harms are there? Our company never allows back-filling, but some companies often back-fill can shorten the driving time. Can you discuss it?
The tube is very thin, so you just need to operate it slowly. There is no danger. Isn't the oxygen tank truck still filled?
The so-called "backflow" is a method of replenishing cooling capacity in order to reduce the startup time of the equipment. When filling liquid, the cooling temperature in the tower should be close to the saturation temperature to reduce metal stress problems due to excessive temperature changes. What remains is economics. Other factors can be ignored.
The main issue is economic, time is money! Back pouring can save a lot of money!
I don’t understand why our leaders don’t allow intrusion. It’s not me who is bragging. Our leadership team feels that they are all well-known figures in the sky. I don’t understand.
Then check your backflow pipeline to see if there is another reason.
I saw a paragraph of points to note in this regard, and I excerpted it for your reference. When pouring liquid (liquid oxygen) into the tower, special attention should be paid to the following points:: 1. Before back-filling liquid, the content of harmful substances in the liquid oxygen in the storage tank or tanker should be analyzed. When total hydrocarbons and grease are high, it is prohibited to back-fill liquid into the main cooling system. 2. When liquid appears in the main cooling system, the best time to exit is when the cooling stage of the air separation system ends and enters the liquid accumulation stage. 3. When using a tanker to backfill liquid, the connecting pipes must be connected correctly and the joints must be strong and not leakage. 4. In order to prevent overpressure in the upper tower, the pressure during backfilling or backfilling should be controlled stably and not too high. ； It is necessary to slowly fill the tower with liquid, coordinate the top and bottom well, and pay attention to pressure changes at any time. 5. According to the rise of the main cooling liquid level, one expander operates and the other expander can operate with reduced capacity (depending on the main cooling height). 6. Control the temperature difference at the hot end of the main heat exchanger within the design range to reduce the cooling loss due to incomplete heat exchange. Control the main cooling temperature difference within the design range to reduce the loss of main cooling liquid. 7. It is recommended to drain part of the main cooling liquid before filling the main cooling liquid and after the liquid filling is completed.
It is good for starting, but it will prolong the argon extraction time. Because when driving normally, the argon component in the main cold water is relatively large and the enrichment is relatively fast. When pouring back, there is almost no argon in the main cold water.
What was said on the 7th floor is very specific. What I want to say is that the fear of hydrocarbon drama is unreasonable. Just be careful not to overpressure and do a liquid oxygen test before pouring.
1. The timing for pouring back the main cold should be when the main cold is thoroughly cooled and liquid appears in the main cold. 2. The main cooling backflow is to pre-cool the backflow pipeline to prevent the oxidation of liquid oxygen from causing overpressure in the upper tower. 3. Control the speed of liquid oxygen backflow during main cooling backflow.