High-temperature-resisting direct burial heat preservation pipe

Abstract

The invention discloses a high-temperature-resisting direct burial heat preservation pipe. The high-temperature-resisting direct burial heat preservation pipe comprises a steel pipe, a pulverized fuelash floating bead foaming heat preservation layer, a glass mat layer, a polyurethane foaming heat preservation layer and a glass fiber reinforced plastics protection layer are sequentially mounted inthe radial direction of the steel pipe, multiple expansion buffer holes parallel to the direction of the steel pipe are formed in the pulverized fuel ash floating bead foaming heat preservation layer, in the radial section of the high-temperature-resisting direct burial heat preservation pipe, the expansion buffer holes are annularly mounted at equal angles in the pulverized fuel ash floating bead foaming heat preservation layer with the circle center of a pipe body of the steel pipe as the circle center, and the pulverized fuel ash floating bead foaming heat preservation layer comprises, byweight part, 40 to 50 parts of pulverized fuel ash floating beads, 20 to 30 parts of polyether polyol, 15 to 20 parts of isocyanate, 20 to 30 parts of epoxy resin, 5 to 6 parts of a catalyst, 4 to 5 parts of a curing agent, and 5 to 10 parts of a foaming agent. When the heat preservation pipe is expanded due to heating, structures of an outer heat preservation layer and a protection layer cannot be damaged, water in a buried layer cannot immerse into the heat preservation pipe, the service life of the heat preservation pipe is long, and the high-temperature steam conveying needs can be met.

Description

Technical field [0001] The invention relates to a direct-buried thermal insulation pipe, in particular to a direct-buried thermal insulation pipe capable of transporting high-temperature media. Background technique [0002] The heating pipes in the prior art mostly use thermal insulation pipes wrapped with a rigid polyurethane thermal insulation layer outside the steel pipes. The thermal insulation pipes of this structure cannot withstand high temperatures and can only be used for the transportation of hot water below 100°C, which cannot meet the requirements for steam transportation. Or high temperature medium requirements such as heat transfer oil. CN106764125A discloses a direct-buried steam prefabricated spherical silicon composite anticorrosive insulation pipe. The insulation pipe includes a steel pipe. The outer part of the steel pipe is a sliding layer, and the outside of the sliding layer is a spherical silicon composite anticorrosive insulation material layer. The outer...

AI Technical Summary

Problems solved by technology

Although this kind of insulation pipe can improve the high temperature resistance of the pipeline, when transporting high temperature media, due to the difference in thermal expansion coefficient between the steel pipe and the spherical silicon composite anti-corrosion insulation material layer and the hard polyurethane layer, the pipeline is likely to cause damage when transporting high temperature media. The spherical silicon composite anti-corrosion insulation material layer and the hard polyurethane layer swell and crack, which not only affects the insulation effect, but also, when the protective layer is damaged, the water in the buried layer will directly immerse into the insulation pipe to the outer wall of the steel pipe, causing corrosion to the steel pipe. Shorten the service life of the insulation pipe

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