RU2241597C2 - Method and device for producing porous mixes - Google Patents

Abstract

FIELD: building, particularly producing porous concrete and ceramic mixes.

SUBSTANCE: method involves mixing solid components with water; bloating the mixture by heating thereof up to temperature of water contained in mixture evaporation. Heating mixture is carried out by preliminary separate heating solid components and water, wherein water is heated up to temperature comparable with water boiling temperature, solid components are heated up to temperature close to water boiling temperature and then heated solid components are mixed with water and mixture is further heated by applying mechanical abrasive force to mixture up to water contained in mixture evaporation; continuing application of mechanical abrasive force; changing mechanical abrasive force to impact mixing force. Device for above method implementation comprises mixing means connected to solid components supply unit and water supply unit, heating members and mixture conveying members. Heating members are installed in water supply unit and in solid components supply unit made as heat-insulated feeder. Feeder includes load-bearing mechanism for solid components transportation from loading hopper to mixing means through heating area constituted by above heating members. The device is provided with rotary mixing unit arranged at mixing means outlet and connected thereto by its inlet pipe. Mixing unit has abrasive members and mixing blades. Abrasive members are formed as ring-shaped extensions arranged at working end surfaces of working discs along alternate concentric circles and extending from loading orifice. Extensions form beaters. Mixing blades are located on peripheries of working discs.

EFFECT: improved quality of obtained mixes.

13 cl, 2 dwg

Description

FIELD OF THE INVENTION

The claimed invention relates to the building materials industry, and in particular to technologies for the preparation of porous concrete and ceramic mixtures for the manufacture of cellular structures.

State of the art

A known method of forming wall blocks of cellular concrete (see patent for the invention of the Russian Federation No. 2044639, IPC: 28 V 1/50. Publ. 09/27/1995). including the preparation of a concrete mixture with the addition of a blowing agent while heating it and supplying it under pressure to the forming channel of the extruder, where the mixture boils. In the method, the mixture is porized through the use of foaming agents and the potential for expansion of the mixture due to the water contained in it is not used.

The ability to expand the mixture due to the water contained in it was used in the method of preparing porous concrete and ceramic mixtures (see copyright certificate for the invention No. 421508, IPC: V 1/50, publ. 30.03.1974), which is the closest in essence of the claimed method by decision and selected for the prototype. The method includes preparing a homogeneous mixture of solid ground components and water, without adding a blowing agent, feeding the mixture into a heat exchanger, where it is heated under overpressure, passing the heated mixture through a throttle during which pressure is released to atmospheric pressure, while part of the mixing water passes into a vaporous state, expanding the mixture, and pouring the expanded mixture into molds. The porosity of the intumescent mixture is controlled by the heating temperature of the mixture.

However, the porous mixture obtained in this way has a “disorganized” pore structure, i.e. pores of various sizes are formed, the formation of large pores, the so-called “cavities” is possible, which reduces the final strength of the foam, leads to heterogeneity of the structure obtained from the mixture of products. In addition, the method is quite complicated and requires constant pressure control, because otherwise, it is possible to boil the mixture in the heater and its subsequent setting and curing, which will inevitably lead to a halt in the process, as well as difficult cleaning work.

Known production line for the preparation of porous concrete and ceramic mixtures (see copyright certificate for the invention No. 421508, IPC: 28 V 1/50, publ. 30.03.1974), containing a continuous mixer associated with a water supply device and a device for supplying solid ground components, for example, cement, clay, sand and other dry solid components, a heating system for the mixture under excess pressure in the form of a heat exchanger having measuring equipment and an adjustable choke connected to the mixer by means of a solution th pump equipped with a safety valve.

Such a solution allows the expansion of the mixture due to the water contained in it. However, heating the mixture in a heat exchanger requires a pressure creating and control system and safety valves in the device, which complicates its design, however, the line does not allow to obtain a homogeneous mixture structure.

The essence of the claimed invention

The claimed invention solves the problem of improving the quality of the products obtained by obtaining a homogeneous finely porous structure of the mixture while simplifying the method and device, allowing to expand the mixture due to the water contained in it.

The problem is solved in that in a method for producing porous concrete and ceramic mixtures, comprising mixing solid components and water and expanding the mixture by heating it to the evaporation temperature of the water contained in the mixture, according to the claimed invention, the mixture is heated first by preliminary separate heating of the solid components and water, which are then mixed, and continue to heat the mixture to the evaporation temperature of the water contained in it by means of mechanical abrasion on the mixture for due to the dissipation of mechanical energy, and after expansion of the mixture, the mechanical effect is continued, changing it to shock-mixing.

The problem is also solved by the fact that in a device for producing porous concrete and ceramic mixtures containing a mixer connected to a solid component supply unit and a water supply unit, heating elements and mixture promotion elements, according to the claimed invention, heating elements are installed in the water supply unit and solid components supply unit, made in the form of a thermally insulated feeder, including a load-carrying mechanism for sequential movement of small amounts of solid components from the loading hopper to the mixer through the heating zone created by the aforementioned heating elements, the device is equipped with a rotary mixing device with abrasive elements installed at the outlet of the mixer and connected with its loading nozzle.

Separate preheating of solid components and water can significantly simplify the task of uniform heating of the mixture, because it is much easier to implement than heating the viscous mass of the mixture. Eliminates the need to create and maintain excess pressure. The solid components and water are heated to temperatures close to the boiling point of water, after which they are mixed and the resulting hot mixture of solid components and water is subjected to mechanical action. Mechanical action is carried out in two stages. At the first stage, the mixture is subjected to abrasion, and mechanical energy is dissipated into heat, which allows the temperature of the mixture to increase by several degrees, which leads to boiling of the water included in the mixture and the mixture swells. After swelling, the mixture continues to exert a mechanical effect on it, changing it to shock-mixing, during which the foamed mixture is subjected to impacts of grinding elements, while the resulting bubbles are crushed, crushed. Thus, the mechanical effect allows not only heating the mixture, but also provides a homogeneous finely porous structure of the mixture, which, in turn, improves the quality of the manufactured products of the cellular structure.

Placing the heating elements in the water supply unit and the solid component supply unit allows separate heating of the mixture components before mixing. The uniformity of heating to the required temperature of cement or other heavy solid components is ensured by the design of the block for supplying solid components, namely, by carrying a load-carrying mechanism that ensures the consistent movement of solid ground components in small portions from the loading hopper to the mixer through the heating zone created by the heating elements. During the movement of cement or other solid components due to the thin layer warm up well, while the amount of movement, depending on the length of the load-bearing mechanism, is selected sufficient for heating. The solution is quite simple, economical and allows you to combine heating with the flow into the mixer.

Providing the device with a rotary mixing apparatus with abrasive elements allows abrasion and shock-mixing mechanical action on the mixture, the sequence of actions being determined by the location of the abrasive and grinding elements.

The above confirms that the claimed method and device meet the criterion of unity of invention.

In the study of other known technical solutions in the art, no solutions have been identified that have similar distinctive features. aimed at solving the problem, which allows us to conclude that the claimed technical solutions meet the criterion of "inventive step".

The foamed mixture is susceptible to rapid setting and subsequent curing. However, this problem is solved in the claimed invention due to subsequent foaming of the mixing of the mixture, the most appropriate is a short-term shock-mixing effect. Therefore, it is advisable to carry out a mechanical action with a simultaneous directed high-speed movement of the mixture in the direction of the discharge point.

The method provides the ability to control the heating temperature of the solid ground components and the temperature of the water, which allows you to adjust the initial temperature of the mixture obtained in the mixer, which determines the porosity of the expanded mixture.

The method also provides for the possibility of regulating the supply of water and solid ground components to the mixer, which is aimed at changing the composition and quantity of the obtained porous mixture depending on technological goals, and allows the inventive method to be used in automatic lines for preparing raw materials and manufacturing products.

As a rotary apparatus, a disembarker can be used, equipped with abrasive elements in the form of ring-shaped protrusions placed on the working end surfaces of the disks along alternating concentric circles diverging from the loading opening and forming a zone of increased hydrodynamic resistance, behind which there are beater and peripheral mixing blades.

The load-bearing mechanism of the feeder can be made in the form of a screw (screw) conveyor.

In a specific case of the implementation of the device, the elements of advancing the mixture can be made in the form of a screw blade of the mixer.

It is preferable to use in the device heating elements, made with the possibility of regulation and equipped with measuring equipment.

In one particular embodiment of the device, the heating elements of the solid component supply unit can be made in the form of a water jacket surrounding the load-carrying mechanism, connected to the water supply unit by hot water and waste water pipelines. Thus, the heated water from the water supply unit is used to heat solid ground components.

However, it is preferable to perform separate heating elements for each block, for example, in the form of heating elements placed in one and the other blocks, which allows you to adjust the heating temperature of water and solid components independently of each other.

To change the composition of the mixture for technological purposes, the device can be equipped with elements for regulating the supply of solid ground components and elements for regulating the supply of water.

It is preferable to equip the loading hopper of solid components with a screening element, which will allow the separation of impurities and lumpy material formations at the input of the device.

List of drawings

Figure 1 - shows a General view of the device, a schematic image; figure 2 is a section aa from figure 1, shows a possible case of abrasion and grinding elements of the mixing apparatus.

Information confirming the possibility of carrying out the invention

The inventive method for producing porous mixtures was implemented by the inventive device.

The device for obtaining porous mixtures contains (see Fig. 1) a block 1 for supplying solid components, a block 2 for water supply, a thermally insulated mixer 3. heating elements 4 installed in a block 2 for water supply and heating elements 5 installed in a block 1 for supplying solid components, a rotary apparatus 6 installed at the outlet of the mixer 3 and connected with it by its loading nozzle, and elements for advancing the mixture in the form of a screw blade 7 of the mixer 3.

Block 1 of the supply of solid components is made in the form of a thermally insulated feeder, including a screw conveyor 8 for sequentially moving small amounts of solid components from the feed hopper 9 to the mixer 3 through the heating zone created by the heating elements 5.

As a rotary apparatus, a dismembrator 6 was used, containing (see Fig. 2) abrasive elements made in the form of annular protrusions 10 located on the working end surfaces of the disks along alternating concentric circles diverging from the loading hole, forming a zone of increased hydrodynamic resistance, and placed behind the mentioned zone beat 11 and the peripheral mixing blades 12. The feed hopper 9 of the solid components is equipped with a screening sieve 13.

The rotation of the screw shaft 8 of the feeder 1 is carried out by means of a frequency-controlled motor 14, the water supply unit 2 is equipped with an adjustable gear pump 15, the motor 16 is designed to rotate the working bodies of the disassembler. The device is equipped with measuring and control equipment associated with heating elements 4 and 5 (not shown in the drawing).

The device operates as follows.

In the water supply unit 2, water is heated, if necessary with additives, to a temperature of 90-98 ° C, which is supplied to the mixer 3 by means of a gear pump 15. At the same time, dry solid ground components are supplied from the loading hopper 9. Sifting through a sieve 13, solid components mixtures, for example cement, clay or other solid components, fall on the screw shaft 8 and are distributed in small portions in the recesses of the screw blades of the screw. As the screw 8 rotates, the solid components are successively moved to the mixing chamber of the mixer 3, through the heating zone created by the heating elements 5, they are heated to a temperature of 95-98 °. In a thermally insulated mixer 3, the heated dry ground components and heated water are mixed to a homogeneous mass, which is fed to the inlet of the dismounter 6 by rotating the screw shaft 7. Depending on the technological goals, the temperature of the mixture is controlled by changing the heating temperature of its components. The composition and quantity of the mixture is regulated by changing the amount of supply of solid components and water by changing the speed of the engines 14, 15.

Getting into the dismembrator 6, the flow of hot (96-98 ° С) mixture under the action of centrifugal forces rushes at a high speed from the center, the axis of rotation of the working bodies of the dismembrator to the periphery where the discharge opening 17 is located. In the central zone, the mixture is subjected to mechanical abrasion from the protrusions 10 , which leads to heating of the mixture by several degrees to the evaporation temperature of the water contained in it. Further, closer to the periphery and the discharge opening 17, the boiling mixture is subjected to the impact of the beaters 11 and the mixing blades 12, while the bubbles of the boiling liquid are crushed and crushed, a homogeneous finely porous structure of the mixture is formed.

Claims (13)

1. A method of obtaining porous mixtures, comprising mixing solid components and water and expanding the mixture by heating it to the evaporation temperature of the water contained in the mixture, characterized in that the mixture is heated first by preliminary separate heating of the solid components and water, while the water is heated to temperatures, close to its boiling point, and the solid components are heated to a temperature close to the boiling point of water, then the heated water and solid components are mixed, and the mixture continues to be heated in the middle by mechanical abrasion of the mixture until the water contained in it evaporates, and after expansion of the mixture, the mechanical effect is continued, changing it to shock-mixing. 2. The method according to claim 1, characterized in that the water is heated to a temperature in the range of 90-98 °, the solid components are heated to a temperature in the range of 95-98 °. 3. The method according to claim 1 or 2, characterized in that the mechanical effect is carried out with simultaneous directional high-speed movement of the mixture in the direction of the place of unloading. 4. The method according to any one of claims 1 to 3, characterized in that the heating temperature of the solid ground components and the temperature of heating the water are controlled. 5. The method according to any one of claims 1 to 4, characterized in that regulate the flow of water and solid ground components. 6. A device for producing porous mixtures, comprising a mixer associated with a solid component supply unit and a water supply unit, heating elements and mixture promotion elements, characterized in that the heating elements are installed in the water supply unit and in the solid component supply unit, made in the form a heat-insulated feeder, including a load-carrying mechanism for sequentially moving solid components from the feed hopper to the mixer through the heating zone created by the above-mentioned heating elements, the device is equipped with a rotary mixing apparatus installed at the mixer outlet and connected with its loading nozzle with abrasive elements made in the form of ring-shaped protrusions placed on the working end surfaces of the working disks along alternating concentric circles diverging from the loading hole and forming a zone increased hydrodynamic resistance, and in the form of beats and mixing blades placed on the peripheral part of the working disks of this app rata. 7. The device according to claim 6, characterized in that the load-bearing mechanism of the feeder is made in the form of a screw conveyor. 8. The device according to claim 6 or 7, characterized in that the elements for advancing the mixture are made in the form of a screw blade of the mixer. 9. A device according to any one of claims 6 to 8, characterized in that the heating elements of the solid component supply unit are made in the form of a water jacket surrounding the load-carrying mechanism connected to the water supply unit by hot water and waste water pipelines. 10. Device according to any one of paragraphs.6-8, characterized in that the heating elements are made in the form of heating elements. 11. A device according to any one of claims 6 to 9, characterized in that the heating elements are made in the form of adjustable elements equipped with measuring equipment. 12. The device according to any one of paragraphs.6-10, characterized in that it is equipped with elements for regulating the supply of solid ground components and elements for regulating the supply of water. 13. The device according to any one of paragraphs.6-12, characterized in that the hopper of the solid components is equipped with a screening element.

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