RU2326858C1 - Method of making heat insulated objects - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: method of making heat insulated objects involves serial loading into a vane-type agitator filled with water: super-thin basalt fibre, thin basalt fibre, aluminosilicate spheres, cement and a foaming agent. The obtained mixture is then mixed for about 6 minutes. After that, the mixture is then put under excess pressure of 0.01 MPa in a mould(s). The formed mixture is the solidified in moulds for about 72 hours at 20 ± 5°C and normal moisture. Later at that same temperature and increased moisture, the mixture is solidified for some more 24 hours. The obtained product is taken out from the moulds and dried at temperature between 40°C and 50°C until fully ready.

EFFECT: reduced heat energy requirements.

3 cl, 1 tbl

Description

The invention relates to the production of heat-insulating products, more specifically products designed to reduce heat loss during operation of industrial equipment for various purposes, as well as pipelines and ducts in buildings, structures and outdoor installations.

To reduce heat loss during the operation of industrial equipment, thermal insulation is used. According to GOST 18109-80, perlite-cement products are used for thermal insulation of industrial equipment at an insulated surface temperature of up to 600 ° C.

Most of the known methods for molding heat-insulating products are characterized, as a rule, by the fact that the main component of the molding mixture in them is expanded perlite sand (SU 1028652 A, from 07.15.1983; SU 1818321 A1, from 05.30.1993 or RU 2203253 C2, from 27.04. 2003).

The closest analogue is the production method of perlite-cement heat-insulating products according to GOST 18109-80, in which the moldable mixture has the following composition (by weight):

- expanded perlite sand with a density of 75-100 kg / m ³ - 43%;

- Portland cement brand not lower than 400-40%;

- asbestos not lower than the 6th group - 14%;

- water - 230-300% by weight of solids.

It should be noted that asbestos, which is contained in a sufficiently large amount of the composition of this mixture, is an undesirable component. In Europe, its use for similar purposes is prohibited.

The manufacturing technology of perlite-cement products according to GOST 18109-80 is as follows.

Asbestos is crushed on the runners when moistened to 30–35% for 15-20 minutes, then fluffed up in a propeller mixer for 20 minutes. The materials are mixed in a horizontal horizontal paddle mixer. The components are fed into the mixer in the following order: asbestos pulp, cement, which are mixed for 5 minutes, then perlite sand is introduced and the mixture is mixed for another 1.5 ÷ 2 minutes. After the mixer, the resulting hydromass is fed to a hydraulic press for molding. Extruded products on metal molds at a specific pressure of 0.05 MPa.

Molded products are heat treated in tunnel dryers according to the following temperature conditions. First, the products are kept at a temperature of 170 ± 200 ° C for 3 ÷ 4 hours. At this time, they warm up, the bulk of the water evaporates. Then the temperature is reduced and the products are held at a temperature of 90 ÷ 100 ° C for 6 ÷ 8 hours. In conclusion, the temperature is increased to 150 ° C and the products are dried to a residual moisture content of 20-30%. The total drying time is 13-16 hours.

You can see that the technology of manufacturing perlite-cement products according to GOST 18109-80 is very energy-intensive: the products are subjected to continuous drying (13-16 hours) at a sufficiently high temperature (100-200 ° C). For this, very bulky and complex technological equipment is used. This should be attributed to the number of shortcomings of the existing process.

The disadvantages of the heat-insulating perlite-cement material include the fact that it has a relatively high thermal conductivity (insufficient heat-insulating ability).

At the same time, the creation and use of energy-saving technologies is among the main directions of development of domestic and foreign industry at present.

An object of the invention is the creation of a new formulation and technology for the manufacture of heat-insulating products, which can reduce the cost of thermal energy in the manufacture of products and increase their heat-insulating ability.

The technical result provided by the use of the invention is the optimal choice of mixture components and processing modes that provide the specified reduction in the required thermal energy.

The specified technical result is achieved in the proposed method of molding heat-insulating products, including sequentially laying in a water-filled working paddle mixer: super-thin basalt fiber, thin basalt fiber, aluminosilicate spheres, cement and foaming agent and mixing the resulting mass for about 6 minutes, then supplying the finished mixture under excess pressure about 0.01 MPa to mold (s), after which the molded mixture is kept in molds for approximately 72 hours at a temperature of 20 ± 5 ° C and normal humidity and then at the same temperature and high humidity, the mixture is kept for approximately 24 hours, the resulting products are removed from the molds and dried at a temperature of 40 ÷ 50 ° C until complete.

Mentioned components necessary to obtain a mixture are preferably added based on the following formulation:

aluminosilicate spheres ⌀ 0.1 ÷ 0.3 mm - 22%;

superthin basalt fiber ⌀ 1 ÷ 2 microns - 0.6%;

fine basalt fiber ⌀ 5 ÷ 7 microns - 1.2%;

cement grade D0 - 71%;

PB-2000 foaming agent - 0.3%;

water - 120 ÷ 150% by weight of dry matter.

The specified increased humidity is mainly 100%.

Achieving the result was made possible thanks to the proposal to introduce aluminosilicate spheres with lower thermal conductivity into the composition of the new heat-insulating material instead of expanded pearlite sand. In addition, to create a porous structure of the material, a foaming agent “working” at normal temperature (without heating the molded product) was introduced into its composition. Creating a porous structure of the molded product leads to a significant increase in its heat-insulating ability.

To increase the mechanical strength of the heat-insulating product, superfine basalt fiber is introduced (in a relatively small amount) into the composition of its material.

Below is a more detailed description of a preferred embodiment of the invention.

According to the invention, the method is as follows. Water is poured into the paddle mixer, the electric motor is turned on, and then the components of the resulting mixture are laid in order: superthin basalt fiber, thin basalt fiber, aluminosilicate spheres, cement, foaming agent. After laying the last component, the mass is mixed for 6 minutes. An overpressure of the order of 0.01 MPa is created in the container with the finished mass, with the help of which the mixture is supplied in special forms. The molded mixture is kept in molds for 72 hours at a temperature of 20 ± 5 ° C and normal humidity. Then at the same temperature and humidity 100% the mixture is aged for another 24 hours. The resulting products are removed from the molds and dried at a temperature of 40 ÷ 50 ° C until fully prepared.

After optimizing the composition of the developed material according to the criterion of achieving maximum heat-insulating ability while maintaining sufficient strength, the following formulation of a new heat-insulating material was obtained, which was called "Thermolight-350":

aluminosilicate spheres ⌀ 0.1 ÷ 0.3 mm - 22%;

superthin basalt fiber ⌀ 1 ÷ 2 microns - 0.6%;

fine basalt fiber ⌀ 5 ÷ 7 microns - 1.2%;

cement grade D0 - 71%;

PB-2000 foaming agent - 0.3%;

water - 120 ÷ 150% by weight of dry matter.

You can see that this technology differs from the technology for the manufacture of perlite-cement products according to GOST 18109-80 with significantly lower costs of thermal energy.

Table 1 below shows the comparative technical characteristics of the products obtained according to the known method and proposed, while the brands of heat-insulating products correspond to the density of their material.

Table 1 The main technical characteristics of products for thermal insulation of industrial equipment at an insulated surface temperature of up to 600 ° C Characteristics Characteristic value for perlite cement products according to GOST brands new thermal insulation "Termolight-350" brands 225 250 300 350 225 250 300 350 400 Thermal conductivity, W / (mK) at an average temperature: 25 ± 5 ° C 0,065 0,067 0,073 0,079 0.051 0.056 0,060 0,068 0,075 305 ± 5 ° C 0.108 0,110 0.116 0.122 0,090 0,094 0,099 0.108 0.115 Bending strength, MPa, not less 0.22 0.23 0.25 0.28 0.18 0.22 0.25 0.31 0.35

Thermal insulation products are usually made in the form of plates, half cylinders and segments of the following sizes:

a) plates: length - 500 and 1000 mm, width - 500 mm, thickness - 50, 75 and 100 mm;

b) half-cylinders: inner diameter - 56, 78, 91, 110, 135, 162, 222 mm; length - 500 and 1000 mm; thickness 500-100 mm;

c) segments: inner diameter - 162, 222, 277, 327, 380, 400 mm; length - 500 and 1000 mm; thickness 80-105 mm.

Thus, the proposed method for the manufacture of heat-insulating products for thermal insulation of industrial equipment at an insulated surface temperature of up to 600 ° C have the following advantages compared to the prototype:

- increased heat-insulating ability (reduced thermal conductivity) - by 15-20%;

- significantly lower cost - 2-2.5 times.

The technological process of manufacturing heat-insulating products from Thermolight-350 material allows to reduce energy consumption by 15-20 times in comparison with the technology for manufacturing heat-insulating products according to GOST 18109-80.

Claims (3)

1. The method of molding heat-insulating products, which consists in sequentially laying a working paddle mixer in a water-filled paddle: super-thin basalt fiber, thin basalt fiber, aluminosilicate spheres, cement and foaming agent, and the resulting mass is mixed for about 6 minutes, then the finished mixture is fed under excess a pressure of about 0.01 MPa into the mold (s), after which the molded mixture is kept in the molds for approximately 72 hours at a temperature of 20 ± 5 ° C and normal humidity and then at the same temperature and yshennoy humidity mixture was held for an additional about 24 hours, the product obtained is removed from the molds and dried at a temperature of 40 ÷ 50 ° C until fully cooked. 2. The method according to claim 1, in which these components are necessary to obtain a mixture, add based on the following formulation: aluminosilicate spheres ⌀ 0.1 ÷ 0.3 mm - 22%; superthin basalt fiber ⌀ 1 ÷ 2 microns - 0.6%; fine basalt fiber ⌀ 5 ÷ 7 microns - 1.2%; cement grade D0 - 71%; PB-2000 foaming agent - 0.3%; water - 120 ÷ 150% by weight of dry matter. 3. The method according to claim 1 or 2, in which the specified high humidity is 100%.