High temperature application door installation

Abstract

This invention comprises a door for gas-tight sealing engagement in an access opening in environments involving high temperature. In one embodiment, the door is a boiler access door provided through a waterwall in a boiler, and includes a tapered insulation plug for sealing engagement in a tapered opening in the waterwall. In a preferred embodiment, the tapered sides are stepped and the insulation comprises multiple layers, which may be of different grades of insulation material. The stepped insulation defines a plurality of linearly aligned contact surfaces for engagement with a plurality of cooling tubes defining the sides of the access opening. This contact with the cooling tubes not only impede flow of hot gas between the door and frame, protecting the seal and the outer portions of the door from the heat, but also result in cooling of the insulation plug. In another embodiment, the door includes a spring loaded sealing plate which is yieldably biased to define a preload and prevent opening and closing movement of the door when the door opening and closing mechanism and/or the door are not in the proper operative position. In a further embodiment, a protective metal sheath is provided on the insulation plug, and includes expansion joints between adjoining plates, with telescoping tabs to maintain the plates in substantial alignment.

Dependencies are inferred from the claim text.