Bellows expansion joint for ash smoothing vertical pipe

Abstract

The invention discloses a bellows expansion joint for an ash smoothing vertical pipe. The bellows expansion joint comprises an inner pipe, supporting plates, a bellows, an outer pipe, padding and a spacer bush. The upper end and the lower end of the vertical bellows are connected with the supporting plates respectively in a sealed mode, the outer pipe is upwards inserted into an inner cavity of the bellows through an inner hole of the lower-layer supporting plate, the inner pipe is inserted into an inner cavity of the outer pipe through an inner hole in the upper-layer supporting plate, the inner pipe is in clearance fit with the outer pipe in a sleeved mode, and the inner pipe and the outer pipe are connected with corresponding supporting plate combination portions respectively to form a bellows-oriented compensation structure. The space between the inner wall of the bellows and the outer wall of the outer pipe is divided into two spaces through the spacer bush fixedly connected between the inner wall of the bellows and the outer wall of the outer pipe, the lining padding located inside the space on one side of the bellows forms an outer-layer heat insulation structure, and an inner-layer heat insulation structure with air as the medium is formed between the inner wall of the spacer bush and the outer wall of the outer pipe. Due to the fact that the bellows expansion joint for the ash smoothing vertical pipe is internally provided with the two heat insulation layers, the bellows is effectively protected against overheat, the bellows is prevented from making contact with conveyed particle materials, needless abrasion is structurally eliminated, and the service life of the bellows is greatly prolonged.

Description

technical field [0001] The invention relates to a pipeline safety device, in particular, the invention relates to an expansion joint. The expansion joint is matched with the pipe before the furnace inlet of the fluidized bed boiler and installed vertically. Background technique [0002] The feeder for the fluidized bed boiler is usually installed in a fixed position. During the operation of the boiler, as the temperature changes, the corresponding thermal expansion and contraction deformation will inevitably occur in the piping system. Normal physical deformation is mainly reflected by axial thrust, which poses a safety threat to the feeder and piping system. In engineering, expansion joints are generally arranged between the return feeder of the fluidized bed boiler and the inlet of the furnace to absorb or compensate the axial thrust and axial displacement. The straight-through corrugated expansion joint commonly used in the prior art is very flexible, has the characteri...

AI Technical Summary

Problems solved by technology

However, the working temperature of the fluidized bed boiler is as high as 850°C to 1200°C, resulting in very bad surrounding conditions. In addition, the straight-through bellows expansion joint in the prior art lacks a thermal protection structure for the bellows of the compensation element, so that the thin-walled bellows The tube is easy to be heated. Once the ambient temperature exceeds the allowable working temperature of the bellows, it will cause an instability accident, which will cause the bellows expansion joint to lose its compensation function.

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