RU2809971C1 - Method for stage homogenization of composite mixtures - Google Patents

Abstract

FIELD: homogenization.

SUBSTANCE: method for continuous mixing of polydisperse materials with organic and mineral technogenic additives, microfiber fillers using a recirculating and multifunctional device. The method for homogenizing polydisperse materials in a recirculating mixer can be used in the chemical, construction, fuel and other industries in the production of composite mixtures and products from them. The method implements a step-by-step process of homogenization of composite mixtures, including sequential and parallel mixing of heterogeneous components using internal devices with a developed helical surface. Internal devices ensure intensive recycling of materials. Homogenization of the initial main components is carried out in a macro-mixing chamber 2 in combination with a micro-mixing chamber or chambers 6 and 7. The preparation of homogeneous composite mixtures from heterogeneous macro- and microadditives is carried out in the additive mixing chamber 7 and separately in the macro-mixing chamber 2 and micro-mixing chamber 6. Obtaining a combined composite mixture from the main components by the method of their sequential macro- and micro-mixing and parallel mixing of additives. Separate preparation of composite mixtures from the main components and a mixture of heterogeneous additives with fiber fillers is carried out in the macro-mixing chamber 2 and micro-mixing 6 and the additive preparation chamber 7 in combination with the intensification chamber for the final mixing of materials 18. Obtaining homogeneous multicomponent mixtures with heterogeneous additives and fiber fillers and combining both material flows - in the intensification chamber for the final mixing of materials 18. The production of a microgranulated composite mixture is carried out in a macro-mixing chamber 2 with micro-mixing chambers 6, 7 and preparation of a mixture of heterogeneous additives installed in parallel, as well as with a final mixing and agglomeration chamber 18 connecting them. The mass ratio of the initial main components prepared in macro- and micro-mixing chambers to the amount of heterogeneous components of the mixture of the additive chamber is set as 80-85% to 15-20%. The content of the macro-reinforcing component of the finished composite mixture does not exceed 10-15%. The content of the micro-reinforcing component in the granulated state is no more than 80%, in addition, the dimensions of the microgranulate of the composite mixture or mixture of additives agglomerated in the intensification chamber for final mixing and microgranulation do not exceed 5-7 mm.

EFFECT: expansion of functionality through the use of polydisperse and fibrous materials with different physical and mechanical characteristics and physical and chemical properties to obtain homogeneous composite mixtures when implementing innovative techniques.

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Description

The invention relates to a method for continuous mixing of polydisperse materials with organic and mineral technogenic additives, microfiber fillers using a recirculating and multifunctional device. The method of homogenizing polydisperse materials in a recirculating mixer can be used in the chemical, construction, fuel and other industries in the production of composite mixtures and products from them.

There are known methods for preparing homogeneous composite mixtures and devices for them with the implementation of various technological tasks. For large-scale and small-scale (macro and micromixing) composite mixtures with a binder and the use of a special mixing chamber and mixing devices.

(RF Patent No. 2505 348, IPC B01F 7/04, application 07.17.2012, application No. 201 213 0359/09. Published 01.27.2014, Bulletin No. 3, mixing method and device for its implementation).

The disadvantage of this method is the production of a heterogeneous mixture, which is associated with the difficulty of moving the starting materials through various units, mixing during reverse rotation of the working bodies and discrete movement of components.

There is also a known method and device for continuous mixing of fibers with a binder (RF Patent No. 2521579, IPC B01/F 7/02, application 05.11.2010, application No. 2011151080/05, publ. 06.27.2014, Bulletin No. 17) characterized in that that the mixing process is implemented in one or several chambers through the use of high-speed needle combs fixed to the shaft (n = 2000-4000 rpm, centrifugal acceleration of the fibers - a _c = (10-30)10 ³ m/sec ² , which is accompanied high energy consumption when implementing the mixture homogenization process.

The closest technical solution is a method for homogenizing polydisperse materials, implemented in a recirculating mixer of combined action (Patent No. 2788202 C1 Russian Federation, IPC A23N 17/00. Recirculating mixer of combined action: No. 2022112968: application 05/13/2022: publ. 01/17/2023 / S. N. Glagolev, V. S. Sevostyanov, A. M. Protsenko [etc.]).

The specified technical solution implements a method for homogenizing the main initial components (siliceous, mineral binders, various fillers, etc., constituting the bulk of the mixture) and various heterogeneous additives (microfibers, plasticizers, pigments, etc.) in interconnected chambers equipped with internal devices with a developed helical surface and providing intensive recycling of material with high quality of prepared mixtures. The chambers are combined into a single technological unit, consisting of a chamber for macro- and micro-mixing of the starting components, a chamber for the homogenization of heterogeneous additives, as well as a chamber for intensifying the final mixing or agglomeration of the composite mixture.

The known method of homogenizing dissimilar components, implemented in a recirculating mixer, has multifunctional technological capabilities for obtaining high-quality homogeneous mixtures with certain combinations of processes for mixing components with various physical and mechanical characteristics (bulk density; geometric shape and granulometry, flowability, coefficients of internal friction, moisture demand, etc. ).

The following set of features coincides with the characteristics of the prototype: implementation of a method for homogenizing polydisperse materials, including processes of sequential and parallel mixing of heterogeneous components in chambers equipped with internal devices that ensure intensive recycling of materials.

The disadvantage of the prototype is the limited technological capabilities due to the strict technological and mechanical interconnection of individual processes, which makes it difficult to implement the maximum possible technological operations in one unit and the functionality of the method.

The problem that the proposed method is aimed at is expanding functionality through the use of polydisperse and fibrous materials with different physical and mechanical characteristics and physical and chemical properties to obtain homogeneous composite mixtures when implementing innovative technologies. And also, resource-saving technologies for the complex processing of organic and mineral technogenic materials with the possibility of obtaining various types of commercial products from composite mixtures. Such technogenic materials, for example, include: highly dispersed carbon black of low-temperature thermolysis technology (T≤500°C, patent No. 2744225 of the Russian Federation); polymer, wood, pulp and paper waste (No. 2724667, No. 2755436, No. 2567519) in a crushed state, mechanically activated siliceous materials and binders (cement, lime); basalt fibrous waste (No. 2692624), fiber fillers obtained from them for architectural and construction mixtures and products, incl. 3D technologies, etc.

The problem is solved due to the fact that the method implements a step-by-step process of homogenization of composite mixtures, including sequential and parallel mixing of heterogeneous components, using internal devices with a developed helical surface. Internal devices ensure intensive recycling of materials.

In the proposed solution, the homogenization of the original main components is carried out in a “macro-mixing chamber in combination with a micro-mixing chamber (or chambers).”

The preparation of homogeneous composite mixtures from heterogeneous macro and microadditives is carried out in the “additive mixing chamber” and separately in the “macro and micro mixing chamber”.

Obtaining a combined composite mixture from the main components - by their sequential macro- and micro-mixing and parallel mixing of additives.

Separate preparation of composite mixtures from the main components and a mixture of heterogeneous additives with fiber fillers is carried out in the “macro- and micro-mixing chamber” and the “additive preparation chamber” in combination with the “chamber for intensifying the final mixing of materials.”

Obtaining homogeneous multicomponent mixtures with heterogeneous additives and fiber fillers and combining both material flows - in the “chamber for intensifying the final mixing of materials.” The production of a microgranulated composite mixture is carried out in a “macro-mixing chamber” with “micro-mixing chambers” installed in parallel with each other and preparing a mixture of heterogeneous additives, as well as with a “chamber for final mixing and agglomeration of the mixture” connecting them.

The mass ratio of the initial main components prepared in the macro- and micro-mixing chambers to the amount of heterogeneous components of the mixture of the additive chamber is set as (80-85)% to (15÷20)%.

The content of the macro-reinforcing component of the finished composite mixture does not exceed (10-15)%.

The content of the micro-reinforcing component in the granulated state is no more than 80%, in addition, the dimensions of the micro-granulate of the composite mixture or mixture of additives agglomerated in the intensification chamber for final mixing and micro-granulation do not exceed (5-7) mm.

The method for implementing stage-by-stage homogenization of composite mixtures is presented in the basic diagram of the movement of material flows (Fig. 1) in a recirculating mixer of combined action, as well as in the diagrams (Fig. 2; Fig. 3; Fig. 4; Fig. 5; Fig. 6; Fig. 7), representing various options for organizing technological processes - mixing methods.

The presence in the method of options for implementing homogenization processes of multicomponent mixtures with heterogeneous additives makes it possible to prepare the mixture in both a polydisperse and microgranular state. Depending on the required technological result, each of the proposed options for the method of homogenization and microgranulation of composite mixtures has expanded variability of practical implementation in various areas of the use of mineral and organic materials (components).

The mass ratio of the initial main components prepared in macro- and micro-mixing chambers to the amount of heterogeneous components of the mixture of the additive chamber should be (80-85)% to (15-20)%. This ratio is determined both by the real practical values of the basic components and mixture of additives for the specified multicomponent mixtures, and by the design and technological design of the working parts of the specified chambers, which have different productivity and corresponding quality assurance of the mixtures.

The content of the macro-reinforcing component of the finished composite mixture should not exceed (10-15)%, which is due to the boundary conditions for the introduction of fiber fillers to improve the quality of manufactured building products or coatings (compressive strength, crack resistance, etc.) from the resulting mixtures.

The content of the micro-reinforcing component in granulated composite mixtures (granules up to (5-7) mm in size) should not exceed 80%, which is due to the need to use special additives during granulation: binders, plasticizers, etc., which should be at least 20%.

The percentage of mixed components indicated in the formula and description is optimal, which was confirmed during pilot-industrial research in the research laboratory “Resource-energy-saving technologies, equipment and complexes” (“RETOK”) BSTU. V.G. Shukhova.

Thus, the range of use of polydisperse and fibrous materials with different physical and mechanical characteristics and physical and chemical properties is expanded to obtain homogeneous composite mixtures when implementing innovative technologies. Including resource-saving technologies for the integrated processing of organic and mineral technogenic materials with the possibility of obtaining various types of commercial products from composite mixtures. Such technogenic materials, for example, include: highly dispersed carbon black of low-temperature thermolysis technology; polymer, wood, pulp and paper waste in a crushed state, mechanically activated siliceous materials and binders (cement, lime); basalt fibrous waste, fiber fillers obtained from them for architectural and construction mixtures and products, incl. 3D technologies, etc.

The essence of the proposed method is illustrated by graphic material, which shows:

in fig. 1 – design diagram for implementing the method of stage-by-stage homogenization of composite mixtures and movement of material flows;

in fig. 2 – stage-by-stage macro and micro mixing of the mixture;

in fig. 3 – stage-by-stage macro and micromixing (a), separate preparation of a mixture of additives (b);

in fig. 4 – sequential macro and micro mixing (a), homogenization of heterogeneous additives with part of the main components of the macro mixing chamber (b);

in fig. 5 – homogenization (a) of a composite mixture of main components and a mixture of heterogeneous additives (b);

in fig. 6 – homogenization of multicomponent mixtures and heterogeneous additives with fiber fillers, combining both material flows;

in fig. 7 – microgranulation of a composite mixture of homogenized main components of a mixture of heterogeneous additives.

The method of stage-by-stage homogenization of composite mixtures (Fig. 1; Fig. 6) is implemented as follows.

At the first stage of the method, the process of homogenization of the main initial components, for example, cement and mechanically activated sand, is performed (Fig. 1; Fig. 2). The homogenized components through the loading hopper 1 are dosed into the macro-mixing chamber 2. Chamber 2 is equipped with single-throw helical blades 3 of recirculation action. Each of the single-threaded screw blades, per one revolution of the shaft, exerts a double impact on the mixed material, which intensifies the internal recycling of material flows and improves the quality of the resulting mixtures. After macro-mixing is completed, the mixture flows through connecting pipes 4, 5 into micro-mixing chambers 6, 7 (Fig. 2). These chambers are equipped with double-threaded helical blades (DVL) 8, which carry out more intense 2 ^- fold recirculation effects on the homogeneous mixture. This ensures intensive micromixing and, as a consequence, uniform distribution of components in local volumes of the homogenized mixture. Unloading of finished products is carried out through pipes 9, 10.

At the stage of “macro-micromixing” of the main components, both two micromixing chambers (Fig. 2) and one micromixing chamber can be used.

Each of the given schemes for organizing the processes of homogenization of composite mixtures significantly expands the technological capabilities of the implemented mixing options.

Similar to scheme I, scheme II (Fig. 3) implements stage-by-stage macro and micro mixing of the main components in chambers 2 and 6 with subsequent unloading of the 2 ^- component mixture through pipe 9 (option “a”).

In parallel, this option realizes the production of a multicomponent mixture of various additives (for example, fillers, pigments, plasticizers, reinforcing fibers - fiber fillers, and other components).

The initial components of the additives are loaded into chamber 7 through the compartments of the hopper 12 (option “b”). In this case, in the chamber 7 for mixing additives, unidirectional transport DVLs 13,14 are used sequentially along the direction of movement of the material (Fig. 1, Fig. 3). Between them there is a pair of multidirectional DVLs 15,16 and then a U-shaped device of intensifying action 17. Through the high-speed action of the U-shaped device on the heterogeneous components of the additives, a complex spatial movement of the components is realized, mixing with each other. The finished mixture of additives is unloaded according to scheme II (Fig. 3) through pipe 10.

Moreover, the mass ratio of the initial main components prepared in the macro- and micro-mixing chambers to the amount of heterogeneous components of the mixture in the additive chamber is (80-85)% to (15÷20)%. This option implements the simultaneous production of composite mixtures of various compositions (macro-micromixing and separate production of additives in chamber 7) and the percentage of their components.

A variant of the method of combined processes of macro and micro mixing of the main components (option “a”) and a mixture of additives with part of the homogenized main components (option “b”) is implemented according to scheme III (Fig. 4). A distinctive feature of the options implemented according to scheme II (Fig. 3) and scheme III (Fig. 4) is the expansion of the technological capabilities of the mixing processes shown in the diagram (Fig. 1).

According to option III (Fig. 4), the process of sequential macro- and micro-mixing is implemented in chambers 2 and 6, obtaining a 2-component mixture, similar to option II (Fig. 3), as well as parallel simultaneous preparation of a mixture of additives in chamber 7 with part 2x component mixture coming from the macromixing chamber 2. The introduction of a certain part of the homogenized main components from the macromixing chamber 2 is carried out due to the operation of the gate device 11.

Thus, this option makes it possible to obtain two types of commercial products: a composite mixture consisting of a mixture of additives (chamber 7) and part of the mixture (30-40%) of the main components (chamber 2), Fig. 4.

More multifunctional technological processes (options) are implemented using four mixing chambers (schemes IV, V and VII), Fig. 5, fig. 6 and fig. 7, respectively. The content of the macro-reinforcing component of the finished composite mixture should not exceed 10-15%, and the content of the micro-reinforcing component in the granulated state should not exceed 80%.

According to scheme IV (Fig. 5), the option of stage-by-stage preparation of the following compositional mixtures is carried out: macro and micromixing in 4 chambers 2 and 6 main components connected in series through a pipe (option “a”), as well as a compositional mixture of additives (chamber 7). This composite mixture consists of more heterogeneous heterogeneous components (including fiber fillers) and is finally intensively mixed in chamber 18 (option “b”) (Fig. 5, Fig. 1). The mixture of additives from chamber 7 enters chamber 18 through the pipe 10 connecting them, and the finished product is unloaded through pipe 26.

The composite mixture is supplied to the material recycling zone, where intensive micromixing is carried out due to DVL 19, 20, which helps to obtain a homogeneous composite mixture.

The device ensures intensive movement of material flows both along the internal (inside the spherical cavities) and external (“spherical cavities – chamber 18”) contours. Thus, internal and external recycling of the composite mixture is realized by supplying the mixture to the zone of the intensifying action device using the discharge DVL 21. This process ensures high-quality homogenization of the composite mixture.

The finished product is unloaded by DVL 24 through the unloading pipe 26. Then, by means of a belt transport device 27, the mixture is sent for further technological purposes (packaging, sending to the consumer, etc.).

According to scheme V (Fig. 6), the option of homogenizing multicomponent mixtures and heterogeneous additives with fiber fillers is implemented. This ensures the unification of two (“a” and “b”) material flows, processed, respectively, in the chambers: “2-6-18” and 2-7-18.”

In the case of obtaining multicomponent composite mixtures consisting of heterogeneous components with different densities, geometric shapes, particle sizes, etc., prone to segregation (stratification) during transportation, it is advisable to present the final product in a microgranular state.

Similar requirements must be observed for special-purpose composite mixtures. For example, in the production of multicomponent composite mixtures (organomineral fertilizers, special mixtures for architectural and construction purposes that require heat treatment; antibactericidal components, etc.), the method of microgranulation is used (Scheme VI, Fig. 7).

In this case, a binder is supplied to the inner chamber 22 (Fig. 1) in a sprayed or vapor state, providing increased adhesive ability (increased adhesive forces) of particles of the composite mixture. After appropriate mixing of the components of the mixture with the binder in the inner chamber, microgranulation of the material occurs in a device with spherical cavities 23, 24. The spherical cavities along their internal contour are covered with a mesh surface, which contributes to intensive volume-spatial movement of the mixture from one cavity to another. Ultimately, the effective formation of spherical microgranules is ensured. The dimensions of the microgranulate of the composite mixture or mixture of additives agglomerated in the final mixing and microgranulation intensification chamber do not exceed 5-7 mm.

As in the previous case (Scheme V, Fig. 6), the unloading and transportation of microgranular products is carried out in a similar way.

The proposed options (Schemes II-VI) present fundamental options for the homogenization of multicomponent mixtures with heterogeneous additives in both polydisperse and microgranular states. Depending on the technological problem being solved, each of the proposed options for homogenization and microgranulation of composite mixtures has expanded variability of practical implementation in various areas of the use of mineral and organic materials (components).

Thus, the method of stage-by-stage homogenization of composite mixtures has expanded technological capabilities for obtaining a wide range of composite mixtures for various purposes (with different physical and mechanical characteristics) due to the organization of sequential homogenization processes: macro-micromixing (Fig. 2), macro-micromixing and homogenization of additives with part of the main components (Fig. 4), homogenization of multicomponent mixtures and heterogeneous additives with fiber fillers (Fig. 6), microgranulation of a composite mixture of homogenized main components of a mixture of heterogeneous additives (Fig. 7), as well as separate production of a mixture of microadditives during step-by-step macro and micro mixing (Fig. 3), homogenization of a mixture of heterogeneous additives with simultaneous mixing of a composite mixture of the main components (Fig. 5).

Claims (1)

A method for stage-by-stage homogenization of composite mixtures, including a process of sequential and parallel mixing of heterogeneous components using internal devices with a developed helical surface, providing intensive recycling of materials, characterized in that the method is carried out in stages, and the homogenization of the initial main components is carried out in a macro-mixing chamber in combination with a chamber or micromixing chambers; the preparation of homogeneous composite mixtures from heterogeneous macro- and microadditives is carried out in the additive mixing chamber and separately in the macro- and micromixing chamber; obtaining a combined composite mixture from the main components - by the method of their sequential macro- and micro-mixing and parallel mixing of additives; separate preparation of composite mixtures from the main components and a mixture of heterogeneous additives with fiber fillers, respectively, in a macro- and micro-mixing chamber and a chamber for preparing additives in combination with a chamber for intensifying the final mixing of materials; obtaining homogeneous multicomponent mixtures with heterogeneous additives and fiber fillers and combining both material flows - in the chamber for intensifying the final mixing of materials; The production of a microgranulated composite mixture is carried out in a macro-mixing chamber with parallel chambers for micro-mixing and preparation of a mixture of heterogeneous additives, as well as with a chamber for final mixing and agglomeration of the mixture that unites them, while the mass ratio of the initial main components prepared in the macro- and micro-mixing chambers to the number of heterogeneous components of the mixture of the additive chamber is set to 80-85% to 15-20%; the content of the macro-reinforcing component of the finished composite mixture does not exceed 10-15%, and the micro-reinforcing component in the granulated state - no more than 80%, while the dimensions of the micro-granulate of the composite mixture or mixture of additives agglomerated in the intensification chamber for final mixing and micro-granulation do not exceed 5-7 mm .