'an inspection device (d) and a method for checking compartmental openings of windbox of supercritical boilers in thermal power plants.'

摘要

This invention describes a method of developing and using a special inspection device for checking the dimensional accuracy of compartmental openings of windbox of once-through supercritical boilers. The windbox is a box type of welded structure consisting of a base plate welded with a plurality of web plates to form multiple compartments. These compartments are the provisions for the fuel and air to enter the boiler. All the compartmental openings of the windbox are to be critically maintained. There is a likelihood of change of dimensions of the compartments during fabrication because of welding induced distortion. The compartmental openings have to be checked during various stages of manufacture. Therefore, there is proposed in this invention, a method of developing a special device and an inspection technique for checking the compartmental dimensions of the windbox. The inspection device consists of a plurality of plates of width slightly lesser than width of the corresponding compartment of the windbox. These plates are then attached to a lengthy rod. This inspection device has to be lifted and inserted into the windbox after properly matching all the compartmental openings. If the compartmental openings are of the required length, then the plates attached to the rod shall easily pass through. In case of change of dimensions due to distortion, the plates attached to the rod in the inspection device will not pass through the compartmental openings thereby serving as quick inspection method.