Patent ID: 7296349

Claim:
A method to construct a steam generator including at least a boiler steel structure, a boiler top main grid having a plurality of main beams, and a gas pass defined by tube walls surrounded by buckstays, the gas pass having a width and the steam generator containing internal components, the method comprising the following steps: a) constructing a plurality of foundations around a boiler base; b) commencing construction of the boiler steel structure on the foundations; c) constructing the buckstay and tube wall modules by joining buckstay modules and tube wall units; d) hoisting the buckstay and tube wall modules into the boiler steel structure under construction, and temporarily placing the buckstay and tube wall modules into an installation position; e) arranging a plurality of lifting beams on the boiler base; f) arranging the main beams of the boiler top main grid on the boiler steel structure; g) aligning and assembling the tube walls; h) hoisting the lifting beams in steps with a plurality of cable hoisting systems, and suspending the internal components under the lifting beams; i) hoisting the internal components to an installation height at which the lifting beams are at an assembly height with the main beams; and j) joining the lifting beams with the main beams and connecting the internal components.