by L Wu, J Cui, HB Zhang, KJ Song, and PS Du
This paper from the proceedings of the IIW 2017 International Conference in Shanghai, China, describes the development of successful welding techniques for zirconium-clad pressure vessels and reactors using narrow gap submerged arc welding, gas tungsten arc welding and some shielded metal arc welding.
Zirconium has excellent corrosion resistance to acid, alkali and variety of metal fluids. It has superior corrosion resistance to niobium, ￼titanium and some other metals in certain corrosive mediums, which makes it suitable for corrosive media where titanium is not.
Zirconium has, therefore, found more and more application in modern petroleum and chemical industries. However, zirconium is among the more expensive metals, which means the cost of pressure vessel manufacturing using full-thickness zirconium plate would be extremely high, especially for large scale high temperature and pressure equipment, prohibiting its widespread use.
On the other hand, zirconium-steel composite plate becomes an economically viable material for the manufacturing of such pressure equipment.
In this paper, welding technology and inspection characteristics of the core equipment – the reactor used for the synthesis of acetic acid by the method of methanol carbonylation – are briefly introduced. Moreover, some details that should be taken into account in the fabrication of zirconium-steel composite plate equipment are briefly described.