FI78450B - ELDBESTAENDIG VAERMEISOLERMASS. - Google Patents

Description

1 73450

Refractory thermal insulation compound

The invention relates to a thermal insulation compound based on a mixture of inorganic substances and pore-forming organic substances, which is intended for thermal insulation of heating units and for incineration only on site.

Refractory thermal insulation compositions, which are mixtures of natural ceramic raw materials, oxides and lightweight fillers, are known. Their fire resistance is determined by the chemical composition of the raw materials of the pulp, while the low thermal conductivity is provided by the foaming agents incorporated in them. It is known that the porosity of refractory thermal insulation masses is achieved by adding diatomaceous earth, foamed vermiculite or perlite, pre-fired and foamed ceramic masses in the form of pellets or combustible organic additives (1, 2).

A disadvantage of the known thermal insulation compositions containing vermiculite or diatomaceous earth is that their fire resistance is limited. They have a maximum operating temperature of 1100 ° C (2).

A disadvantage of the known heat-insulating compounds with good fire resistance is that they have a high thermal conductivity (1).

The object of the present invention is to provide a refractory thermal insulation mass which has at the same time good refractory and correspondingly high operating temperature and low thermal conductivity.

30 This object is achieved by preparing a refractory thermal insulation composition which is characterized in that it contains 100 parts by volume of a mixture of 20 to 50 parts by weight of refractory clay and / or kaolin and / or refractory fine inactive filler of the type alumina, aluminosilicate chamotte, mulch chamotte, silica, chromium (III) oxide, magnesium oxide, magnesium silicate, zirconium silicate, or a mixture of said substances 5-30 parts by weight of liquid 2,78450 or solid water-soluble inorganic binder and 5-50 parts by weight; and 50 to 180 parts by volume of a combustible organic substance impregnated with a liquid inorganic binder.

5 Rice, wheat, oats, barley or rye husks, sawdust or cellulose pulp, or a mixture of these substances may be used as non-combustible organic substances.

The liquid or solid water-soluble inorganic binder is a mixture of acidic metal phosphates of the aluminum, chromium or magnesium phosphate type, aluminum sulfate, a mixture of metal phosphates and sulfates, an organosilicate compound of the ethyl silicate type, or an aliquot metasilicate.

In order to expand the range of refractory thermal insulation compounds to be manufactured and their field of application and application, the refractory clay and / or kaolin contained in the refractory compound is replaced by a refractory fine-grained inactive filler of the type alumina, aluminosilicate, oxide, meltite, oxide, magnesium oxide, magnesium silicate, zirconium silicate or a mixture of these substances and not more than 50% by weight.

To insulate the thermal aggregates by casting or melting, a raw mass is used which is converted into a refractory thermal insulation mass by the heat emitted by the thermal aggregate. The result is the carbonization and combustion of the combustible organic matter incorporated in the pulp, into which the inorganic binder has been impregnated, without partially losing its shape and thus becoming pores having a microcellular structure.

The refractory thermal insulation mass can be used to make furnace walls or bricks by casting in special molds or casting frames and curing the mass at ambient temperature with the aid of curing accelerators. In this case, the combustion of the pulp can be carried out by means of the heat of the heat unit or in an industrial furnace.

3,73450 The advantages of the refractory heat-insulating compound according to the present invention are the following: the combination of good refractory and correspondingly high operating temperature and low thermal conductivity in the same product, the possibility to vary these parameters over a wide range and the use of cheap and widely available raw materials. All these advantages ensure a wide and versatile use of refractory mass for the insulation of different types of heat aggregates and allow the mass to be used in the form of a raw mixture as well as as refractory products.

The object of the present invention is illustrated and described in detail by means of the following use examples.

Example 1 15 A mixture of the following ingredients is prepared:

Refractory clay 20 parts by weight

Kaolin 10 parts by weight

20 parts by weight of alumina

Aluminum phosphate binder 20 parts by weight 20 Water 30 parts by weight 100 parts by volume of this mixture are added 150 parts by volume of rice husks impregnated with aluminum phosphate binder, and then the mixture is homogenized in a mixer. The resulting plastic mass is applied in its raw form by sealing or casting on furnace vaults or using frames on vertical walls. As a result of the heat of the heat unit, a refractory thermal insulation material with a bulk density of 600 kg / m, a thermal conductivity of 30.12 at 20 ° C, 0.12 Bt / mK and a maximum operating temperature of 1500 ° C is formed.

Example 2

Same as Example 1, the only difference being that wheat husks are used instead of rice husks.

35 Example 3

Same as Example 1, the only difference being that oat husks are used instead of rice, 78450 4 husks.

Example 4

Same as Example 1, the only difference being that instead of rice husks, a mixture containing equal proportions of rice, rye and barley husks is used.

Example 5

Prepare a mixture of the following ingredients:

Refractory clay 15 parts by weight

Kaolin 15 parts by weight 10 Sodium metasilicate aqueous solution 3 (density 1.7 g / cm) 30 parts by weight

20 parts by weight of silica

Water 20 parts by weight to 100 parts by volume of this mixture are added 140 volumes of 15 parts by volume of sawdust impregnated with aluminum sulphate. The plastic mass thus obtained is applied in the raw state by sealing on the brickwork of industrial furnaces. The thermal insulation mass is burned using the effect of furnace heat 3 and has a bulk density of 550 kg / m and a thermal conductivity of 20.10 ° C at 0.10 Bt / mK.

Example 6

As in Example 5, the only difference is that a mixture containing equal proportions of rice husks, sawdust and pulp-pulp is used instead of sawdust.

Example 7

Prepare a mixture of the following ingredients:

Kaolin 30 parts by weight

Aluminosilicate chamotte 20 parts by weight 30 Aluminum chromium phosphate binder 30 parts by weight

Water 20 parts by weight to 100 parts by volume of this mixture are added 120 parts by volume of sawdust impregnated with aluminum phosphate binder, and the mixture is homogenized. Just before use, 5 parts by weight of aluminate cement are added to 35 to 95 parts by weight of the mixture. The new mixture formed is molded in a wooden or 5,78450 metal mold or metal frame and allowed to cure at ambient temperature for 1-2 days. The available ingot bricks have sufficient mechanical strength and are ready to be used for lining the furnace walls.

5 The bricks are burned using the heat of the heating unit. This refractory thermal insulation compound is suitable for insulating chimney walls and other parts of industrial furnaces.

Its maximum operating temperature is 1350 ° C.

Example 8 10 A mixture of the following ingredients is prepared:

Refractory clay 10 parts by weight

20 parts by weight of silica

Kaolin 10 parts by weight

Ethyl silicate 20 parts by weight 15 Water 30 parts by weight To 100 parts by volume of this mixture are added 150 parts by volume of rice husks impregnated with an aluminum phosphate binder. The plastic mass thus obtained is applied in the raw state by sealing to the vaults of the furnaces or to the vertical walls using frames 20. The effect of the heat of the heat unit results in the formation of a refractory thermal insulation material with a bulk density of 550 kg / m, a thermal conductivity at 20 ° C of 0.11 Bt / mK and a maximum operating temperature of 1400 ° C. Literature references 25 (1) Refractories and their use; translated from Japanese; Moscow (1984), p. 288 - 304 (2) High temperature insulation; Interceram 1979, No. 4, p. 416 - 420.

Claims (3)

78450 Thermal insulation mass based on a mixture of inorganic substances and pore-forming organic substances, intended for thermal insulation of heating units and incineration only on site, characterized in that it contains 100 parts by volume of a mixture of 20 to 50 parts by weight of refractory clay and / or kaolin and / or refractory finely divided in-10 active filler of the type alumina, aluminosilicate fireclay, mullite fireclay, silica, chromium (III) oxide, magnesium oxide, magnesium silicate, zirconium silicate or a mixture of said substances of 5 to 30% by weight -15 silica inorganic binders and 5 to 50 parts by weight of water; and 50 to 180 parts by volume of a combustible organic substance impregnated with a liquid inorganic binder. Refractory thermal insulation compound 20 according to Claim 1, characterized in that rice, wheat, oat, rye or barley husks, sawdust or cellulose pulp or a mixture thereof are used as the combustible organic material. Refractory thermal insulation compound 25 according to Claim 1, characterized in that The liquid or solid water-soluble inorganic binder is a mixture of acidic metal phosphates of the aluminum, chromium or magnesium phosphate type, aluminum sulfate, a mixture of metal sulfates and phosphates, an organosilicate compound of the ethyl silicate type or an alkali metal metasilicate. S