STIRRER APPARATUS

Abstract

This utility model relates to devices for mixing solutions, suspensions, and emulsions and may 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 in a device with mixers consisting of a housing with a lid on which inlet pipes for the liquids being mixed are located, a bottom with a mixture outlet pipe, and a drive mounted on the lid and connected to a vertical shaft on which paddle mixers are mounted. The blades of adjacent mixer shafts are installed at an angle of 90° relative to each other, and the blades of each mixer located on opposite sides of the shaft are installed at a 90° rotation.

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 that comprises 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 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 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 leading half coupling, respectively [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 fixed on a drive shaft, a low-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, the driven half-coupling of which is fixed on 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 pages].

[0013] The reasons that prevent the achievement of the specified technical result include low mixing intensity in tall apparatuses, such as extraction columns, due to insufficient interaction of the flows of mixed liquids between adjacent mixers.

[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 placed, a bottom with a pipe for removing the mixture, a drive mounted on the cover and connected to a vertical shaft on which paddle mixers are placed, wherein the blades of the mixer shafts adjacent in height are installed with an inclination at an angle of 90° relative to each other, and the blades of each mixer located on different sides of the shaft are installed with a rotation of 90°.

[0016] Installing the blades of adjacent stirrer shafts at a 90° angle to each other creates pressure in the mixed liquids normal to the blade surface. The dynamic pressure from the blades of adjacent stirrer shafts directs the mixed liquid flows toward each other, colliding them, causing additional mixing due to flow fragmentation and bifurcation. However, this pressure and the high-velocity flows do not collide the liquid flows from the two upper blades. However, rotating the blades of each stirrer, located on opposite sides of the shaft by 90°, creates pressure transmitted by the high-velocity flow of the mixed liquids from the two upper blades.

[0017] Fig. 1 shows the proposed design of the apparatus with stirrers,

[0018] in Fig. 2, 3 - rotation of the mixer blades.

[0019] 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.

[0020] The installation of the 8 blades of the adjacent stirrers of the shaft 7 at an angle of 90° relative to each other and the installation of the blades 8 of each stirrer located on opposite sides of the shaft 7 with a 90° turn create a normal pressure to the surface of the blades 8. The high-speed pressure is transmitted to the liquids themselves towards each other (in Fig. 2, the lower blades). This pressure and the high-speed flows do not collide the flows of the mixed liquids of the two upper blades 8 (in Fig. 2, the two upper blades). However, the rotation of the blades of each stirrer located on opposite sides of the shaft by 90° creates a pressure transmitted by the high-speed flow of the mixed liquids of the two upper blades of the stirrers (in Fig. 3). The collision of the flows causes vortices in the entire volume of the liquid, which contributes to intensive mixing.

[0021] The apparatus with stirrers of the proposed design operates as follows.

[0022] When the branch pipe 6 is closed, the liquids to be mixed are fed through branches 3 and 4, filling the housing 1 with them. The drive is turned on, which rotates the shaft 7 with the paddle stirrers at a speed of ω. The lower blades 8 (Fig. 2), installed at an angle of 90° to the adjacent stirrer blades 8 along the height of the shaft 7, 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 the turbulence of the flow and the intensity of the process. The rotation of the upper stirrer blades 8, located on opposite sides of the shaft 7, by 90° also creates additional pressure, transmitted by the high-speed flow in the horizontal direction.

[0023] Thus, when mixing liquids with the blades 8 of the shaft 7 of the mixers adjacent in height and each mixer with blades 8 located on different sides of the shaft 7 and turned 90°, high-speed flows of the mixed liquids towards each other are created in one revolution of the shaft, which intensifies the mixing process.

Claims

An apparatus with mixers, consisting of a housing with a cover on which pipes for supplying mixed liquids are placed, a bottom with a pipe for removing the mixture, a drive mounted on the cover and connected to a vertical shaft on which paddle mixers are placed, characterized in that the blades of the mixers adjacent in height to the shaft are installed with an inclination at an angle of 90° relative to each other, and the blades of each mixer located on different sides of the shaft are installed with a rotation of 90°.

Images