Does a synthesis tower with an annual production capacity of 300,000 tons require a lifting frame?
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Our company’s ammonia synthesis tower uses a Cassali-type tower. During visits to other plants, I saw that some of them had large lifting frames, while others did not; they only had maintenance platforms. I asked how equipment can be lifted for maintenance in the absence of such large lifting frames
Regarding the issue of lifting large frames, some plants do have facilities for lifting such frames, which are quite tall and require high costs; the initial investment is substantial. However, due to the high reliability of current ammonia synthesis towers, there are few opportunities for maintenance, resulting in these frames remaining idle throughout the year； Now, by changing the design approach, and given the maturity of modern mobile crane technology, it is not necessary to design a large lifting framework for the ammonia synthesis tower; instead, only maintenance platforms need to be designed and constructed. This reduces upfront investment and eliminates long-term constraints, as cranes can be used for lifting during catalyst loading and subsequent maintenance tasks, at a relatively low cost. Comparing the options of lifting a large frame or not, it is clear that the latter is more practical and cost-effective.
Agree with the comment above; for ammonia synthesis on such a scale, there is no need to construct a large lifting framework.
Whether a large framework is needed depends mainly on the production conditions. If the internal components of the synthesis tower have to be removed for inspection every year, or if the catalyst needs to be replaced every two to three years, then it’s certainly necessary to build a large framework. If the operation of the synthesis unit is stable, the internal components function well, and the catalyst can last around five years, then a regular crane is sufficient. Our plant produces 100,000 tons of synthetic ammonia; when we installed the new synthesis tower, we planned to build a large framework, but due to cost considerations, we didn’t do so and only constructed an inspection platform. As a result, the synthesis tower didn’t operate properly, and the internal components had to be removed for inspection, repair by welding, or replacement almost every year. The cost of using cranes (500-ton cranes) over these years has been higher than the cost of building a large framework, and these costs will continue to arise as long as production continues. Therefore, whether to build a large framework for the synthesis tower depends on the conditions of one’s own factory.
If there is a large crane available, there is no need to use a lifting frame； If not, consider that hiring a large crane is expensive; especially when unexpected problems arise with the internals of the synthesis tower and they need to be lifted out for repair, this is not very convenient. It would be better to have a lifting frame, as the investment required for this may be less than that of a large crane. If there is, save it if you can.
Our factory has a production capacity of 40,000 tons; the coal contactors need to be replaced only once every five or six years, and the framework is completely a waste
It’s not necessary; the ammonia synthesis catalyst needs to be replaced only every 12 to 15 years, and a crane is sufficient for the replacement process.