To ensure that the high-pressure equipment we manufacture for the fertilizer industry corresponds to the latest state-of-the-art, we have long maintained close working relationships with licensors and material producers. This SBN was a pioneer in the extensive use of Safurex®- a super duplex grade developed by Swedish steel producer Sandvik AB and the Dutch process licensor Stamicarbon B.V. For this, our engineers had to develop the necessary welding technologies in conjunction with Sandvik. SBN is already producing a new generation of pool condensers and pool reactors, according to Stamicarbon's Urea 2000 process, which significantly increase productivity in urea plants. This equipment demands new fabrication methods and strategies, if only because of its large dimensions.
Schoeller-Bleckmann Nitec GmbH supplies custom high pressure equipment, built either in monowall or multilayer-wall construction. Our multilayer technology has shown its worth in numerous reference projects and has been successfully in use for many decades for the most varied applications.
Classic monowall construction
Irrespective of specifications such as pressure and diameter, SBN can offer high-pressure reactors in classic monowall design with wall thicknesses of up to 300 mm. Therefore all SBN heat exchangers can also be manufactured in monowall design. The high-pressure shell sections are either manufactured from hot rolled and longitudinally-welded plates or from seamless forged shell parts.
Our multilayer construction has many benefits
SBN's internationally proven multilayer design can be used to advantage anywhere where high pressures are combined with large-dimensioned high-pressure vessels and shell lengths (for example in urea reactors, pool condensers and pool reactors or ammonia converters).
Particular advantages of SBN's multilayer design
Manufacturing the shell from elements with low thicknesses (about 8-10 mm) produces better metallurgical characteristics, such as, a higher yield strength and stability.
For processes involving high corrosion attack, either the core shell is produced from corrosion-resistant material or an appropriate loose lining is installed The higher the operating pressures and diameters or lengths of the pressure vessel are, the more advantageous is the weight ratio between multilayer and monowall design.
Significantly greater safety reserves are achieved by the more elastic overall behaviour of the shell, as well as through the redundancy resulting from the multilayer construction that prevents an expansion of damages through the entire vessel wall.
Stress cracks and the susceptibility to brittle fractures are practically negligible. And even during pressure test, the behaviour is similar to that in monowall construction.