|
EFFEICIENT WIND TOWER MANUFACTURING |
|
Introduction |
One of the established sources of renewable power is wind energy. With the growing demand for wind energy, the demand for wind towers also increases. The challenge for wind tower producers is to build towers to client specifications in the most efficient and profitable way. The requirements for towers for on shore and off shore are nearly similar, except for steels for offshore applications where extreme temperature requirements are to be met. Welding is the most widely accepted practice to build wind towers. This article provides insights into requirements for increasing productivity of tubular wind towers. |
|
The design sets the rules for production |
- The design, choice of material and material thickness determine the required welding and cutting solutions
- The height of the tower determines the number of shells to be fabricated
- Weld geometries need to be designed for fast production
|
1. The joint types |
Joint types vary with plate thickness to obtain optimal strength at the lowest weld volume. |
|
2. The production flow |
Cutting and welding are two important steps of a series of steps in the production of a wind tower. A standard flow lay out is described below and some details of the various steps are given thereafter.
|
|
3. Cutting |
- With modern cutting machines and software, steel plates are perfectly cut and prepared in a reliable and accurate process
- High quality bevelling is crucial for successful welding
- All sides of the same plate must be bevelled for the joint preparation
- Bevel types per side may differ, for example for joints with different material thickness tapering is adopted. This design also reduces stress concentration at the joint (refer figure below).
|
|
4. Rolling and forming |
|
Cut and bevelled plates are rolled into conical shapes (above) and tack-welded (described in 6 below).
|
5. Welding |
- Welding is a major time factor in the production of a wind tower and comprises of tack welding, longitudinal welding and circumferential welding.
- The cost of welding is a small part of the total costs
- Investing in efficient automated welding solutions increase productivity substantially
|
6. Tack welding
|
|
7. Longitudinal welds |
After tack welding, longitudinal joints are welded with the submerged arc welding process, both on the inside and outside. This can be done in a separate station or in the same station, where the circumferential welds are also carried out. Two popular practices adopted for longitudinal welding are described below.
|
(i) Growing line principle |
|
(ii) Added lines principle |
|
8. Longitudinal welding station |
|
9. Flanges |
|
10. Fit-up |
|
11. Circumferential welds |
|
12. The door frame |
|
13. Blasting & painting
|
After the shells are welded, blasting and painting are essential to preserve the tower in the field |
14. The tower segment |
|
The production results are:
- High quality welded wind tower segments
- Produced with safe and ergonomic equipment
- Solutions that enable high productivity.
|
Ador Welding Ltd. support
The welding and cutting solutions come with valuable support and commitment to allow customers to reach their full potential:
- Training at all levels
- In-depth seminars with the industry experts
- Productivity audits
- Establishment of welding procedures
Please contact cmo@adorians.com for assistance in selecting welding equipment (MMAW/ SAW/ FCAW/ Automation Systems) and consumables, cutting equipment as well as training of engineers/ welders for maximising productivity in wind tower fabrication.
|