CS268382B1 - Thermal insulation with increased thermal resistance - Google Patents

Abstract

Thermal insulation consists of a dark-colored layer of material with a higher density, connected in the direction of heat flow, to a light-colored layer of material with a lower density. A reflective layer is formed between the two layers.

Description

The invention relates to thermal insulation with increased thermal resistance.

Dense materials, such as fireclay, which have a relatively high bulk density, are used to insulate heat aggregates and equipment that need to be thermally insulated. Therefore, it is possible to use them in thick layers, as the use of weaker layers overheats the walls of the units, which represents significant heat loss and also the risk of injury to the operator.

Significant technical problems occur when using a material with a lower bulk density. Fibrous materials have problems with their attachment, they cannot be used as construction materials and in most operations the glass degrades - the glassy phase becomes crystalline and thus the fibers lose their elasticity, break and disintegrate. in the case of solid aggregates heated by both solid fuels and fuel oil, the fibers are attacked by sulfur combustion products, in the case of glaze firing furnaces and glass aggregates, the fibers are degraded by subliming alkali metals.

When using materials of the type of comparison refractory concrete or foam fireclay, their thermal resistance is significantly lower, which is reflected either in the need for considerable reinforcement of the walls of the aggregates or in the reduced thermal efficiency of the aggregates.

. The above-mentioned drawbacks are eliminated by the thermal insulation with increased thermal resistance according to the invention, which consists in the heat flow direction consisting of at least one dark colored layer of higher bulk density material, e.g. a material with a lower bulk density, for example a foamed sand-lime mass. A reflective layer is formed between the dark colored layer of higher bulk density material and the light colored layer of lower bulk density material.

The application of the subject of the invention makes it possible to use for the insulation of construction materials with a thermal resistance which is close to the thermal resistance of fibrous materials.

An illustrative composition of thermal insulation with increased thermal resistance is given in the examples;

Example 1

A combination of aerated refractory concrete and foamed sand-lime material is used for the thermal insulation of the electric furnace, for a temperature of 1,000 ° C.

In the direction of heat flow, the insulation consists of lightweight lightweight refractory concrete with a density of 1,268 kg and a volume comparison of 43.93% with a layer thickness of · 70 mm. Another layer is formed of foamed calcium silicate material of white color with a density of 673.2 kgm ^-3 and a volume porosity of 75.84% with a layer thickness of 60 mm where the combination of these materials is X / Wm ^first * ^'1 / ^! ² / 1,000 ° C, © 4- / m ² s ^-1 /0.0408.10 ^-6 .

Example 2

Phosphate-bonded refractories, aerated refractory concrete, shotcrete and foamed sand-lime are used to insulate the blast furnace cover for temperatures up to 1,730 ° C.

In the direction of heat flow, the insulation consists of a burnt refractory with a phosphate bond with a bulk density of 2,000 kg.ma and a thickness of 140 mm, followed by a -3 r layer of aerated refractory concrete with a bulk density of 1,250 kg.ma and a thickness of 60 mm with a spray of white alkaline shotcrete. matter. Another layer with a density of 700 kg.m and a thickness of 60 mm is made of foamed sand-lime material.

Claims (2)

OBJECT OF THE INVENTION 1. Thermal insulation with increased thermal resistance, characterized in that it consists in the direction of heat flow of at least one dark-colored layer of material with a higher bulk density, for example a phosphate-bonded refractory compound combined with at least one light-colored layer of material and a lower bulk density. for example, an unfoamed lime-slag mass. 2. Thermal insulation according to claim 1, characterized in that a reflective layer is formed between the dark-colored layer of higher bulk density material and the light-colored layer of lower bulk density material.