Service life of nitrogen-hydrogen compressors

This post was last edited by Green Grass Walk on 2009-9-4 09:15. In reciprocating compressors, after being in use for a certain period of time, their main load-bearing components should have been replaced. The components that have not been replaced should be checked by a professional manufacturer; it is advisable to replace them as well. For example, the crosshead, connecting rod, cylinder liner, etc. should be replaced. Not to mention easily worn components such as bearing shells. Most of the compressors discarded by our factory are those for which the repair costs were too high, and thus they had to be scrapped to meet production needs.

Since it is a relocation and renovation project, the compressor was in use and under maintenance up until the relocation; therefore it can still be used, but it requires a thorough inspection and overhaul before use. Many factories use three or more models of compressors in parallel, and the key is that the pressure ratings and the number of stages must be compatible. However, there are too many compressor models, and the variety of compressor accessories makes equipment management difficult.

Yes, it can be used, but the main question now is how many more years these old compressors will be able to function Is it reasonable to design the new compressor and the process flow while still having to take into account those three old compressors with an annual ammonia production capacity of only 20,000 tons? A compressor with an annual ammonia production capacity of 5,000 tons only requires a factory building that is 18 meters wide, while one with a capacity of 40,000 tons needs a building that is 24 meters wide; moreover, the required height of the building also differs. If it’s a 24-meter-long factory building, would a small compressor look good there? If the factory buildings are constructed separately, in order to expand production and replace the compressors in the future, it will be necessary to demolish and rebuild the 18-meter-wide compression building, which entails considerable costs. Although the cost of the equipment is lower, the costs associated with equipment inspection, transportation, and the disassembly of the equipment’s piping are still significant. Roughly speaking, moving three old compressors will cost over 6 million, while a compressor with a capacity of 40,000 tons will cost over 10 million. Although this saves more than 4 million, the capacity is reduced by half. And it’s also old equipment – is that suitable?

You must be a state-owned enterprise; so don’t be too picky about it. State-owned enterprises only take into account the one-time investment costs, with no consideration given to operating expenses. Everyone understands the reason without it being explained. Our company carried out technical upgrades in 2005; the proposed plan was to build a new air separation unit. Since the head office had no expertise in this field, the proposal clearly stated that with the annual operating costs of the two existing 6,000-cubic-meter air separation units, it was possible to afford another unit with a capacity of 18,000 cubic meters. But in the end, the existing equipment was reused; oxygen permeation and oxygen pistons were added. The power consumption was 3500 kw/h, and it did not fit with the currently in-use internal compression air separation system, so it was forced to be connected to the same pipeline. There are so many problems!

The four old ammonia synthesis compressors in our plant produce 150,000 tons of ammonia per year, while the new turbine compressor produces 300,000 tons per year. To keep up with the times, state-owned enterprises have their own approaches; it’s up to us to figure out how to convince the group’s leadership that our plans are correct and that they should follow our course. It depends on how those in charge handle various issues, so that \"unreasonable leaders can become reasonable.\"”

It is highly recommended to discard compressors that have been in use for 28 years! The compressors here have been in use for up to 38 years! ! ! Cracks have been found in the high-pressure pipelines on multiple occasions; fortunately, they were all detected and addressed in a timely manner! And many problems are difficult to solve!

The four old ammonia synthesis compressors in our plant produce 150,000 tons of ammonia per year, while the new turbine compressor produces 300,000 tons per year. To keep up with the times, state-owned enterprises have their own approaches; it’s up to us to figure out how to convince the group’s leadership that our plans are correct and that they should follow our course. It depends on how those in charge handle various issues, so that \"unreasonable leaders can become reasonable.\"”

As long as something is still in use, it means it can be used. Due to long-term use, worn-out parts or problems that arise during operation are not always replaced or repaired promptly. Due to the relocation, it is necessary to take into account the factory’s actual financial situation as well as the company’s future direction; companies that lack advantages will surely lose their competitiveness in the future. Therefore, a reasonable choice should be made based on the energy consumption level.

1. In the process of relocating and upgrading old enterprises, it is not sufficient to simply move them; otherwise, everything will be destroyed as a result. This is especially true for nitrogen fertilizer production – after a company is relocated, the financial costs become unmanageable, as its profit margins are too low； 2. Since a relocation is necessary, this once-in-a-lifetime opportunity should be seized to carry out comprehensive technical upgrades and renovations. The company after the relocation should focus on industry-leading technologies, tap into managerial potential, create new advantages in production and manufacturing costs, and stimulate new vitality within the enterprise ； 3. It is essential to give top priority to careful consideration; identify the differences and similarities between relocation and construction from scratch. Seize the advantages of relocation firmly, keep a focus on relocation, avoid deviating from this approach, create new advantages through relocation, and then achieve further miracles ； 4. Regarding your compressors, in my opinion, operating equipment involves issues related to maintenance and scheduled repairs; there is no issue of a specific service life, only technical standards for major, medium, and minor repairs ； There must be standards for phasing out equipment; otherwise, a large amount of spare parts are wasted and financial costs increase. The enterprise ends up working for the bank, and in the end state-owned enterprises become the bank’s ‘slaves’” ； Employees of private enterprises end up working in precarious conditions ； 5. Moving is simply moving; moving and modifying are forms of cooperation, but moving and searching should not be confused, especially when it comes to mechanical equipment. This is just my personal opinion.

Another issue is that the standards from 28 years ago are completely different from those in use today. According to current standards, many instruments and electrical devices need to be replaced; although the machines function properly when in use, once these devices are taken apart, moved, and reinstalled, they become dysfunctional, and some of them can even no longer be started. Domestic companies all share one common problem: they focus only on investment costs and pay no attention to operating costs, which is exactly the opposite of what foreigners do. Not to mention anything else, moving requires so much effort – far more than installing new equipment does. It’s not a big deal per se, but I’m worried that after putting in so much effort to move it there, it will ** in just a few months – that would be a huge loss.