Doubt everything (lesson)
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Anything is possible. The cooling effect of the acid absorption cooler in our newly commissioned sulfur-based sulfuric acid production plant seems to deviate significantly from what was designed; the temperature of the acid does not drop to the required level, and the plant’s capacity does not reach the designed maximum. Neither the design institute nor the manufacturer of the acid cooling cooler can provide an explanation. We have also tried to find the cause, and our main suspicion is that there is some issue with the equipment manufacturing. It was not until more than a year later, when checking for scaling in the acid cooler, that it was discovered that there were numerous instrument packaging boxes inside the tube bank at the water inlet side (probably that type of plastic corrugated paper that cannot degrade over 50 years); these boxes apparently blocked about 1/3 of the tubes. After cleaning, it’s not so easy to increase the acid temperature when driving. The pool was cleaned very thoroughly before the test run – why did this happen? It might have been placed there by someone during the construction of the circulating water pipes, and it wasn’t noticed. So anything is possible; no potential factor should be overlooked. This post was last edited by bht11 on 2007-8-29 22:49]
There are regulations for all these aspects, but the quality of the workers at construction sites varies; often it’s not intentional, it’s just a matter of wanting to save time! Think about it: who would dare to do such a thing in those highly sensitive times? Some practices from the Cultural Revolution were still advisable! This post was last edited by in the blink of an eye on 2007-8-29 14:23]
Before the start-up of our company’s sulfuric acid plant, cotton-padded jackets were still found during the purging of the steam pipes; it is likely that they were placed there by the construction workers, as it was winter at that time.
If things continue like this, who knows – maybe one day a person will be blown out! During the shutdown for maintenance last year, double-sided welding was required for the pipe joints, which meant it was necessary to open access holes in the pipes to carry out the welding. To ensure safety, the number of welders on site was counted several times, in order to prevent anyone from remaining inside!
The probability of such problems occurring is too high, mainly due to the quality of the construction and maintenance workers. There was a set of purification equipment consisting of cooling towers that worked well initially, but stopped functioning after one maintenance session. No one was able to identify the cause, so in the end an additional cooling tower was installed in parallel, along with an extra acid cooler. Only after the modification was completed did the manufacturer realize that the blind flange at the end of the acid separation pipe of the original cooling tower had been washed away, causing the circulating fluid to flow down along the tower wall and fail to exchange heat with the flue gas. After the blind plate is installed, the existing cooling system fully meets the cooling requirements. It turns out that the workers were careless during the inspection, which resulted in an unnecessary installation of a system.
Although there are some issues with the workers’ competence, it’s not the whole story; many unexpected things can happen in chemical production, and many accidents occur precisely because they were unforeseen. I once found a rusty, broken watch inside the low-temperature shift catalyst of an ammonia synthesis plant ； I picked up a pair of gloves from the water separation tank (the backflow valve has been checked countless times, and the water discharge volume remains very low). A tube with a diameter of 50 couldn’t possibly get clogged; it was only when the container was taken apart that it was discovered. A gas welder was working on a 5-meter-high platform, cutting pipes; he was standing on the pipe. Since he didn’t see that someone else was also cutting near the corner, he almost fell to his death while cutting – fortunately, his safety belt saved him. Someone else, while cutting the patterned boards under their feet at the top of the tower, drew a circle under their feet just like in an animation, and they fell down. Fortunately, the distance between the top floor and the floor below was small, so they were unharmed! Ask him; he said he was too focused on his work and didn’t notice! Alas! It’s beyond imagination! !
Thank goodness! We did not purchase a larger acid cooler.
Many workers lack a sense of responsibility, are lazy, and don’t take things seriously; it’s necessary to supervise them properly. During construction, it’s easy to leave items such as gloves and scraps of cloth inside equipment and pipes!
Haha, someone up there has pinned this post again; it seems quite interesting
The poster is referring to that design firm
:lol:lol:lol, it’s funny, but it’s also sad! Many systems are merely formalities; management and a sense of responsibility fall short! I remember that over a decade ago, when I was the manager of the quality and technical department at a capsule manufacturing plant, the sales department reported that customers had found cigarette butts, lipsticks, and other items inside the packaging boxes. The factory manager scolded us quality control staff harshly. Later, I spoke to the manager and said that this was a GMP-compliant facility; if smoking wasn’t prohibited throughout the entire plant and if there was no better training and monitoring for workers entering the clean rooms, even more ridiculous things could happen.