Construction process of low-temperature high-flame-retardant cold storage sprayed with rigid polyurethane foam insulating layer

Abstract

The invention relates to a construction process of a low-temperature high-flame-retardant cold storage sprayed with a rigid polyurethane foam heat preservation layer, and belongs to the technical field of heat preservation in cold storage. The method comprises the following steps: 1) integrally paving a layer of iron plate on a wall body of the refrigeration house; (2) supporting columns are installed on the iron plate at intervals, and neodymium-iron-boron magnets are fixed to the two ends of each supporting column; (3) another iron plate is placed and installed at the other end of the supporting column, and the iron plate is attracted to the neodymium iron boron magnet at one end of the supporting column; (4) foam is sprayed between the two layers of plates supported by the supporting columns, the spraying direction of the spraying gun is parallel to the wall, and the expansion and growth direction of the foam is parallel to the wall; according to the method, under the condition that the density of the B1-level flame-retardant heat preservation layer is not changed or even reduced, the compressive strength of the foam in the parallel direction of the wall is improved by one time, the penetrating and cracking conditions of the foam are greatly reduced, the problem of a heat bridge does not exist, and the heat preservation effect of the refrigeration house is good.

Description

technical field [0001] The invention relates to a low-temperature and high-flame-retardance spray-coated polyurethane rigid foam insulation layer cold storage construction process, which belongs to the technical field of cold storage internal heat preservation. Background technique [0002] Large space, high walls, and few safety exits are the architectural characteristics of cold storage. The large space leads to the rapid spread of smoke and poisonous gas after a fire occurs, which is very unfavorable for workers in the thick smoke to escape. At the same time, the large-span nature of the cold storage structure space determines that once a fire breaks out, the building may collapse. The large-span structure needs the support of corresponding building components, so the selection of steel structures and prestressed concrete slabs or light-weight components becomes the first choice. The fire-resistant collapse limit of the steel structure is only 8 minutes, which can easily ...

AI Technical Summary

Problems solved by technology

The disadvantages are: (1) When pouring foam with a thickness of 40-80mm, because the height of one-time pouring foam is generally at least 300mm, which is far greater than the thickness of a spray foam layer of about 30mm, the higher the height of one-time pouring foam The more serious the orientation, the worse the physical properties of the foam; (2) There are many voids between the foams poured into the wall for multiple pouring foams, because the foam after the first pouring is 30 The double expansion ratio makes the height difference of the bottom surface very large, resulting in the accumulation of the second raw material in the lowest small piece, which intensifies the height difference of the bottom surface after expansion, resulting in many cavities at the intersection of each pouring foam, resulting in the actual insulation of the cold storage The effect is reduced; (3) The foam contains a large number of keels and high-impact PP material insulation rods and screws. These thermal conductivity coefficients are far greater than the insulation foam, resulting in a decline in the actual insulation effect of the cold storage

[0009] The deficiencies of this patent are even more serious. In addition to the above four problems, because the entire insulation wall insulation foam (calculated according to the conventional 200mm insulation layer) is all poured, the internal molecular orientation of the poured foam will be more serious, and the foam injected each time The problem of many cavities between them is more serious; and the foam contains a large number of keels without insulation rods, which will form a large number of thermal bridges. These factors will lead to a decline in the actual insulation effect of the cold storage

It is precisely because the infusion process will lead to serious molecular orientation in the foam, and the cells are elongated into ovals with a relatively high length and diameter. The problem of many cavities between the foams perfused is serious. At present, there is basically no perfusion in cold storage construction Process, mainly two processes of spraying and plate assembly

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