Regarding the thickening of the hoisting cylinder for tall towers
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This post was last edited by gn_1984 on 2018-1-11 at 13:25. Regarding the lifting of tall towers, when designing, the location of the lifting lugs is not taken into account; when it is necessary to thicken the cylinder, there are generally two solutions: 1. The first solution is to determine the specifications of the lifting lugs as well as their location before manufacturing, and to decide on the wall thickness of the thickened cylinder as well as its length (width). This method is commonly used, provided it is approved by the designers. 2. The second approach: Before manufacturing, purchase and arrange the materials according to the thickness specified in the drawings. When it is determined that the position of the lifting lugs and the wall thickness of the thickened sections are greater than those specified in the drawings, and it is not desired to purchase thicker plates, it is recommended to add a reinforcing ring around the outside of the lug sections. How should the thickness and width of this reinforcing ring be determined? Could there be any issues with lifting in this case? What is the feasibility and reliability of this solution when the equipment is large and weighs hundreds of tons? How to determine it? Please ask experienced users to analyze how to design and manufacture this reinforcement ring Thank you.
In the past, to save costs, project manufacturers would use expansion rings at the trunnion locations on the inner wall of the equipment; these were large H-shaped steel sections or channel steels, which were tightened against the inner wall using high-strength bolts. The lifting has been completed using this method, after which the expansion ring is removed and the internal components are installed. I hope this helps you.
So how do you calculate these reinforcement specifications? Are there any standards or calculation methods to follow? Thank you.
What if the tower encountered is large in diameter, a packed tower with many internal components, and it’s not possible to use this reinforcement structure inside it?
As for whether there are other methods, I don’t have any evidence or experience to give an accurate answer. I just checked our documents – the largest tower that was lifted weighed 300 tons; its diameter was 2000 mm and its wall thickness was 40 mm. There was also another tower with a diameter of 3400 mm and a wall thickness of 22 mm, whose lifting weight was 115 tons. In all cases, lifting was carried out using this method. The equipment has now been installed in place and tested. I don’t have the calculation method either, but related information can definitely be found online. Since someone has already done it, our project shouldn’t be the first of its kind. When the original poster finds a good method, we can discuss it and share it!
In fact, it often happens that at the time of tower design, or even during the manufacturing phase, the equipment installation party has not yet determined a specific lifting plan; as a result, it is difficult to decide on the placement of lifting lugs or reinforcement sections in a timely manner during the procurement or manufacturing of the equipment materials. Therefore, the lifting and reinforcement plan for equipment is generally provided by the installation company, which includes solutions for strengthening the lifting lugs, in an effort to avoid altering the equipment’s original structural design.
Thank you, I’ve learned something. I have encountered the method you provided before as well. And the equipment was successfully lifted, just as you said.