STIRRER APPARATUS

Abstract

This utility model relates to devices for mixing solutions, suspensions, and emulsions and can find application in the chemical, petrochemical, light, food, pharmaceutical, mechanical engineering, and other industries, as well as in environmental processes for sludge and wastewater treatment. The technical result of the proposed design of a device with mixers is increased mixing intensity due to counter-directional flows of the liquids being mixed. This technical result is achieved by the device with mixers, which consists of a housing with a lid containing inlet pipes for the liquids being mixed, a bottom with a mixture outlet pipe, and a drive mounted on the lid and connected to a vertical shaft containing paddle mixers. The paddles of each mixer, located on opposite sides of the shaft, are mounted at a 90° angle relative to each other.

Description

[0001] The utility model relates to devices for mixing solutions, suspensions, emulsions and can find application in the chemical, petrochemical, light, food, pharmaceutical, mechanical engineering and other industries, as well as in environmental processes for treating sludge and wastewater.

[0002] Devices with paddle mixers are known, having one or more vertical plates mounted on a vertical shaft [Molokanov Yu.K. Processes and apparatuses for oil and gas refining. - M.: Chemistry, 1980, p. 343, 408 pp.].

[0003] The disadvantages of these stirrers include weak stirring intensity, which requires an increase in mixing time, especially for difficult-to-mix highly viscous and non-Newtonian liquids.

[0004] A mixer is known, comprising a housing, a central high-speed mixer, equipped with a float made in the form of a torus, rigidly fixed in its upper part, installed coaxially with the housing, and a hydraulic coupling with a driven half-coupling made in the form of a branch pipe, which is fixed on the blades of the low-speed mixer and is installed axially symmetrically with the shaft, and a leading half-coupling is rigidly fixed on the shaft, wherein the leading half-coupling and the opening in the branch pipe have an oval shape, and the ratio of the length of the minor axis of the oval in the opening of the branch pipe to the length of the major axis of the oval of the leading half-coupling is:

[0005] ,

[0006] where L and l are, respectively, the lengths of the minor axis of the oval in the opening of the branch pipe and the major axis of the oval of the driving half coupling [Patent for Utility Model of the Russian Federation No. 119640, IPC BO1F 7 / 16, published on August 27, 2012].

[0007] The disadvantages of this mixer design include insufficient mixing intensity of the liquid near the housing walls, as the slow-speed mixer blades, when rotating slowly, create stagnant zones in the peripheral volumes of the mixer. Furthermore, in column-type devices (column extractors), the central high-speed mixer does not mix the liquids in the upper part of the device, creating stagnant zones, which also reduces the overall mixing intensity.

[0008] A mixer is known that contains a housing, a central high-speed mixer secured to a drive shaft, a low-speed mixer equipped with a float made in the form of a torus, rigidly secured in its upper part, installed coaxially with the housing, and a hydraulic coupling, the driven half-coupling of which is secured to the blades of the low-speed mixer, wherein the driven half-coupling is made in the form of a cylindrical pipe installed axially symmetrically with the shaft, and the ratio of the internal diameter of the pipe to the diameter of the shaft is:

[0009] ,

[0010] where D and d are the internal diameter of the pipe and the shaft diameter, respectively [Patent for Utility Model of the Russian Federation No. 124185, IPC BO1F 7 / 16, published on March 20, 2013].

[0011] The disadvantages of this design include insufficient intensity of mixing of particles and droplets of the dispersed phase in tall column-type apparatuses, which reduces the speed of hydromechanical, heat and mass transfer processes at the interface between the continuous and dispersed phases.

[0012] The closest technical solution, in terms of its combined features, to the claimed object and adopted as a prototype, is a device with stirrers, consisting of a housing with a lid, on which are located pipes for the supply of mixed liquids and the discharge of the mixture. A drive is mounted on the lid, connected to a vertical shaft on which stirrers (of the paddle type) are located at some distance from each other. The angle of inclination of the blade is 45° relative to the horizontal plane of rotation [Strenk, F. Mixing and apparatuses with stirrers. Leningrad: Chemistry, 1975, p. 62, 384 pp.].

[0013] The reasons that prevent the achievement of the specified technical result include low mixing intensity in tall apparatuses with light fractions due to insufficient interaction of the flows of mixed liquids both between adjacent mixers and in the upper part of the apparatus.

[0014] The technical result of the proposed design of the apparatus with stirrers is an increase in the intensity of mixing due to the flows of mixed liquids directed towards each other.

[0015] The technical result is achieved in that in a device with mixers, consisting of a housing with a cover on which the pipes for supplying the liquids to be mixed are located, a bottom with a pipe for discharging the mixture, a drive mounted on the cover and connected to a vertical shaft on which paddle mixers are located, and the blades of each mixer, located on different sides of the shaft, are installed with a rotation of 90°.

[0016] Setting the stirrer blades on opposite sides of the shaft at a 90° angle to each other creates a pressure in the mixed liquids that is normal to the blade surface. The dynamic pressure from the blades, positioned on opposite sides of the shaft at a 90° angle, directs the mixed liquid flows toward each other, colliding them, causing additional mixing due to flow fragmentation and bifurcation. This intensively mixes the liquids both between adjacent stirrers and in the upper part of the apparatus above the stirrers.

[0017] Fig. 1 shows the proposed design of the apparatus with stirrers, Fig. 2 and Fig. 3 show the rotation of the stirrer blades.

[0018] The proposed apparatus with a stirrer comprises a cylindrical body 1, a cover 2 with pipes 3 and 4 for feeding two mixed liquids, a bottom 5 with a pipe 6 for removing the mixed mixture, a drive (not shown in the figures) mounted on the cover 2 and connected to a vertical shaft 7, on which paddle stirrers with blades 8 are placed at a distance from each other.

[0019] By installing blades 8 on opposite sides of shaft 7 at a 90° angle, normal pressure is applied to the surface of blades 8. The dynamic pressure is transferred to the liquids themselves, moving toward each other (Figs. 2 and 3). The collision of the flows causes turbulence throughout the entire volume of liquid, even in tall apparatuses. This eliminates the need for additional agitators along the shaft. Intensive mixing occurs both between adjacent agitators and in the upper portion of the apparatus above the agitators, enabling intensive mixing of suspensions and emulsions with light fractions.

[0020] The apparatus with stirrers of the proposed design operates as follows.

[0021] With nozzle 6 closed, the liquids to be mixed are fed through nozzles 4 and 5, filling housing 1. The drive is turned on, rotating shaft 7 with paddle stirrers at a speed of ω. Blades 8 (Figs. 2 and 3) of each stirrer, located on opposite sides of the shaft and installed at a 90° angle, create an axial pressure normal to their surface (Pascal's law). The high-speed flows of these blades 8, directed towards each other, collide and strike with force, increasing flow turbulence and process intensity. Additional pressure is created, transmitted by the high-speed flow in both the vertical and horizontal directions.

[0022] Thus, when mixing liquids with each mixer with blades 8, located on opposite sides of shaft 7 and turned 90°, high-speed flows of mixed liquids towards each other are created per one rotation of the shaft, which intensifies the mixing process.

Claims

An apparatus with mixers, consisting of a body with a cover on which are placed pipes for supplying the liquids to be mixed, a bottom with a pipe for discharging the mixture, a drive mounted on the cover and connected to a vertical shaft on which are placed paddle mixers, characterized in that the blades of each mixer, located on opposite sides of the shaft, are installed with a rotation of 90° relative to each other.

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