RU173464U1 - HEAT INSULATION STRUCTURE FOR PIPELINES - Google Patents

Abstract

The utility model relates to a heat-insulating structure designed to warm the pipelines of hot and steam heat supply in order to reduce heat losses on the heat carrier. The technical result is the expansion of the operating temperature range of the expanded polystyrene foam. The technical result is the thermal insulation design for pipelines, consisting of two identical parts, representing a segment hollow half cylinder, joined together in a longitudinal plane around the pipe with the formation of ring heat insulating shell. Each of the parts consists of an inner segment of a hollow half-cylinder made of polystyrene foam coated on all sides with a layer of closed-porous rigid polyurethane foam or polyisocyanurate. In addition, each of the two parts of the structure has longitudinal and transverse protrusions and grooves on the connection surfaces around the pipe, having the same geometric dimensions and acting as connecting elements.

Description

The utility model relates to a heat-insulating structure designed to warm the pipelines of hot and steam heat supply in order to reduce heat loss on the coolant.

From patent US 3223125, publ. 12/14/1965 A known design for thermal insulation of pipelines, consisting of two semi-cylindrical parts connected in the longitudinal direction around the pipeline using special locking protrusions. Moreover, each semi-cylindrical part is a monolithic part of a foamed polymeric material, for example, foamed polystyrene (US patent No. 3223125, publ. 12/14/1965).

The disadvantages of the known design are restrictions on operation at temperatures above + 85 ° C and the lack of protection of the insulating material from external influences.

Design for thermal insulation of pipelines, consisting of two semi-cylindrical parts, connected in the longitudinal direction around the pipeline using special locking tabs. Moreover, each semi-cylindrical part is a multilayer part consisting of a main inner layer of foamed polymeric material, for example, foamed polystyrene, a middle layer of sheet fibrous inorganic material and an outer coating of metal sheet (a close analogue of the proposed thermal insulation is US Pat. No. 4,287,245, publ. 01.09 .1981).

The disadvantages of the known design are the restriction on operation at temperatures above + 85 ° C, since when this temperature is exceeded, the polystyrene is destroyed, as well as the complexity of the design.

The task to which the claimed utility model is directed is to create thermal insulation for pipelines that can withstand higher temperatures. The problem is solved through the use of materials with lower coefficients of thermal conductivity.

The problem is solved in that, according to a utility model, the heat-insulating structure for pipelines comprises two identical semi-cylindrical parts made with the possibility of joining in the longitudinal plane and forming an annular heat-insulating sheath, each half-cylindrical part made of polystyrene foam coated on all sides with a layer of closed-porous rigid polyurethane foam. Or as a coating material can be used closed-cell rigid polyisocyanurate. In addition, the surfaces of two identical semi-cylindrical parts intended for their connection can be made with longitudinal and transverse protrusions and grooves having the same geometric dimensions in each standard size and acting as locks for more reliable connection of two identical semi-cylindrical parts around the pipe.

In FIG. 1 - thermal insulation design for pipelines, cross section.

The heat-insulating construction for pipelines comprises two identical semi-cylindrical parts 1 and 2 made with the possibility of joining in the longitudinal plane around the pipe intended for insulation and the formation of an annular heat-insulating shell. Each of them is made of polystyrene foam 3, coated on all sides with a layer of closed-porous rigid polyurethane foam 4. Or each of them can be made of polystyrene foam 3, coated on all sides with a layer of closed-porous rigid polyisocyanurate 4.

Thermal insulation for the pipeline is made by combining two materials that are mutually complementary and can improve basic characteristics, such as temperature of use and thermal conductivity.

In shape, each element (liner) made of polystyrene foam 3 is a hollow half-cylinder or a segment of a hollow half-cylinder, which can be with beveled or with non-beveled edges. Each of the parts 1, 2 can have both standard and individual geometric shapes and sizes for thermal insulation of pipes. Each part 1, 2 has on the surfaces in the connection plane around the pipe longitudinal and transverse protrusions and grooves 5, which are made with the same geometric dimensions in each typical size. Longitudinal and transverse protrusions and grooves 5 act as locks for more reliable connection of semi-cylindrical parts around the pipe.

Each semi-cylindrical part of the proposed thermal insulation is made by joining in one piece, on specially designed forming equipment. Liquid polyurethane foam or polyisocyanurate and a hollow half-cylinder made of polystyrene foam or a segment of a hollow half-cylinder with beveled or not beveled edges made of polystyrene foam, the density of which is not lower than 10 kg / m ^{3, are} combined in one piece.

As a result, after the polyurethane foam has hardened, or if polyisocyanurate has been used, a structure is formed which consists of a hollow half cylinder with an outer layer of polyurethane foam relative to the insulated pipeline, or if used, it is made of polyisocyanurate and a liner as a middle layer of expanded polystyrene and a layer of polyurethane foam, or if used, of polyisocyanurate. That is, the design is made in such a way that polyurethane foam, or if used, polyisocyanurate, completely covers the hollow half-cylinder or segment of the hollow half-cylinder made of polystyrene foam from all sides.

In the manufacture of the proposed thermal insulation, closed-cell rigid polyurethane foam or closed-cell polyisocyanurate is used as the materials of the outer layer, and expanded polystyrene as the material of the inner layer.

Closed-cell rigid polyurethane foam is produced by an exothermic reaction between the polyol components and the isocyanate. Where the polyol as one component is a hydroxyl-containing compound, which when combined with the isocyanate forms a polyurethane foam of liquid form and color from light yellow to brown, which includes a mixture of polyester, catalyst, foaming component, foam regulator and extinguishing agents.

Closed-pore polyisocyanurate - a heat-insulating material that contains up to 99% of closed pores, has a low coefficient of thermal conductivity (λ = 0.021 W / m ° C), which allows it to be used as a heat-insulating material for flat and pitched roofs.

The synthesis of polyisocyanurate is based on polymers such as polyol and isocyanurate, the ratio of the components for polymerization is 1 to 2. The polymerization reaction is carried out at a higher temperature than polyurethane polymerization, which causes the "extra" isocyanurate to enter into the polymerization reaction with itself, forming more durable and strong connections. Thus, a new, more stable material is obtained - polymerized isocyanurate reinforced with polyurethane (PIR).

Polyisocyanurate has increased chemical resistance, resistance to ultraviolet and better flame retardant properties compared to polyurethane foam.

The thermal conductive properties of thermal insulation based on polyisocyanurate significantly exceed the properties of traditional thermal insulation materials.

As polystyrene foam, a material manufactured in accordance with GOST 15588-86 "Polystyrene foam" is used.

The restriction on the use of expanded polystyrene for insulation of pipelines transported by hot water or steam is associated with the destruction of expanded polystyrene when the temperature is exceeded above + 85 ° C. When applying the proposed design of thermal insulation with an external protective sheath made of polyurethane foam or polyisocyanurate, a decrease in temperature is achieved at every 1 cm of the thickness of the outer insulation layer made of polyurethane foam or polyisocyanurate with respect to the insulated pipe by 20 ° С. The outer layer of the structure of polyurethane foam or polyisocyanurate due to its adhesive properties provides the possibility of reliable attachment to it of a protective or decorative shell, including those protecting against the damaging effects of ultraviolet rays.

With the same geometry of products from homogeneous polyurethane foam or polyisocyanurate, this design is cheaper from 30% to 60% based on the cost of raw materials.

Claims (2)

1. The heat-insulating structure for pipelines, comprising two identical semicylindrical parts made with the possibility of connecting in the longitudinal plane and forming an annular heat-insulating shell, characterized in that each identical semicylindrical part is made of polystyrene foam coated on all sides with a layer of closed-porous rigid polyurethane foam. 2. The heat-insulating structure for pipelines according to claim 1, characterized in that the surfaces of two identical semi-cylindrical parts intended for their connection are made with longitudinal and transverse protrusions and grooves having the same geometric dimensions and acting as locks for a more reliable connection of the semi-cylindrical parts around the pipeline.

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