RU2625471C1 - Device for mixing liquids and powders with liquid - Google Patents

Abstract

FIELD: machine engineering.

SUBSTANCE: device for mixing liquids and powders with liquid in the reservoir contains a rod with a working element fixed to one end, with the possibility of its rotation and longitudinal oscillatory movement. The working element is made in the form of three discs rigidly fixed on the rod at the same distance from each other. Along the surface periphery of the outermost discs, n cylindrical pins are mounted, directed with free ends toward the central disc and displaced relative to each other over the disk surface at the same angle α=360°/n. On each of the central disc surfaces, there are co-axially mounted n cylindrical pins offset from the pins of the outermost discs by an angle α/2. On each of the discs, through holes are made, evenly located on their surface. The rod rotation speed is (500÷2700) rpm, the frequency of its longitudinal oscillations is (5÷30) Hz, and the amplitude of the oscillations is not less than 0.8 cm. The distance between the discs, the height and the diameter of the pins, the total area of the holes in the disc and their diameter are determined by algebraic relationships.

EFFECT: invention provides the most complete mixing of various liquids and powders in a liquid to obtain a uniform composition and a uniform volume distribution of solid particles.

2 cl, 5 dwg

Description

The invention relates to metallurgy, construction, paint and varnish and other industries.

Known hydrodynamic mixer [1]. It contains a flow chamber with a cavitator installed in it in the form of a truncated cone, facing a large base towards the entrance of the chamber. The cavitator has slots of a pyramidal shape located at an acute angle to its axis and directed by the apex along the flow. The liquid, getting into the slots, swirls and, due to narrowing, increases the flow rate until the formation of a cavitation flow regime.

A device for mixing particles of a substance with a liquid is known, which contains a container, an inlet for placing particles of a substance in a container, means for spraying a liquid over particles of a substance in a container, an agitator located in a container, and an outlet for discharging a substance mixed with liquid from container [2]. A shaft with a set of disks having an elliptical shape and inclined to the shaft at an angle (45 ÷ 80) degrees is located in the container in an inclined position. The device is difficult to manufacture and not efficient enough to work.

Known mixer nanoparticles with liquids [3]. It contains a cylindrical body, a fluid supply pipe to be mixed with nanoparticles, on the other side of the body a swirl made in the form of radial blades mounted inside the body at an angle to its axis on the same side of the body. A pneumatic or mechanical nozzle, a supply of nanoparticles, and a cochlear tube for discharging a mixture of liquid with nanoparticles from the mixer are mounted on its axis opposite the fluid swirl inside the housing.

A known device for processing, in particular for cleaning or degassing, molten metal, which contains an element exposed to the processed molten metal and means imparting a rotational movement of the metal around a practically vertical axis to separate impurities by centrifugal or gravitational force [4].

The closest in technical essence to the proposed device is a mixer selected as a prototype, which contains a rod and a working body fixed at one end in supports, formed by curved blades [5]. The working body consists of two parts, the blades of each part form a dome with a flanging according to the maximum diameter, are additionally curved in the longitudinal direction and rotated relative to their longitudinal axes, while the domes are flanged interconnected. The blades of one dome can be shifted in the radial direction relative to the blades of the other by an angle of 90 ° inclusive, and in a particular case by an angle of 20 °. Both domes may be the same. The disadvantage of the prototype is the complexity of the design.

The technical result of the present invention is the most complete mixing of different liquids, mixing solid microparticles into a liquid to obtain a uniform composition and a uniform distribution of solid particles.

The technical result of the invention is achieved by the fact that a device has been developed for mixing liquids and powders with liquid in a tank, comprising a rod with a working body fixed at one end with the possibility of its rotation and longitudinal oscillatory movement. The working body is made in the form of three disks rigidly fixed to the rod at the same distance from each other. Along the periphery of the surfaces of the extreme disks, n cylindrical pins are mounted coaxially, directed by their free ends towards the central disk and displaced relative to each other on the surface of the disk by the same angle α = 360 ° / n. On each of the surfaces of the central disk, there are coaxially n cylindrical pins displaced relative to the pins of the extreme disks by an angle α / 2. Through holes are made on each of the disks, evenly spaced on their surface. The speed of rotation of the rod is (500 ÷ 2700) rpm, the frequency of its longitudinal vibrations is (5 ÷ 30) Hz, and the amplitude of the vibrations is at least 0.8 cm. The distance between the disks, the height and diameter of the pins, the total area of the holes in the disk and their the diameter is determined by the relations

H = (0.3 ÷ 0.4) D,

h ₁ = (0.8 ÷ 0.9) H,

h ₂ = (0.45 ÷ 0.55) H,

d = (0.07 ÷ 0.08) D,

_Holes S = (0.2 ÷ 0.3) πD ^2/4,

d _resp = (0.1 ÷ 0.2) D,

where H is the distance between the disks; D is the diameter of the disks; h ₁ - the height of the pins mounted on the extreme disks; h ₂ - the height of the pins mounted on the central disk; d is the diameter of the pins; _Holes S - total area of the holes in the disc; d _holes - hole diameter.

The rod with the working body is made with the possibility of movement in the tank in horizontal and vertical directions.

The invention is illustrated by drawings.

FIG. 1 - General view of the working body.

FIG. 2 - scheme of the working body.

FIG. 3 is a general view of the device.

FIG. 4 - video frames of the process of distribution of glass balls in the tank.

FIG. 5 shows the structure of an alloy sample obtained without using the device (Fig. 5a) and using the device (Fig. 5b).

The positive effect of the invention is due to the following factors.

1. The working body, made in the form of three perforated disks with pins placed on them, provides effective mixing of liquids and powders with liquid due to the formation of a volumetric vortex flow in the tank during rotation and longitudinal oscillatory movement of the working body. Volumetric vortex fluid flow creates a "funnel", the lower end of which is the working body of the device. The swirling fluid flow promotes uniform mixing of liquids or powders with the liquid.

2. The choice of rotation speed (500 ÷ 2700) rpm, frequency (5 ÷ 30) Hz and an amplitude of at least 0.8 cm of longitudinal vibrations of the rod with the working body was carried out on the basis of experiments. With these parameters, two zones are formed with intense mixing between the disks of the working body. Due to the rupture of the liquid into microjets, which collide at high speeds, mutually penetrating each other, the process of mixing the microjets with captured powder particles intensifies. A cavitation mechanism is also possible in which caverns are formed in the fluid flow. When the cavities collapse, microbubbles form, which also contributes to the intensity of fluid mixing.

3. The angular displacement of the pins of the extreme disks by an angle α / 2 α = 360 ° / n was determined experimentally from the conditions of intense vortex formation in the tank and uniform mixing of liquids and powders with liquid.

4. Relations for choosing the geometric characteristics of the device

H = (0.3 ÷ 0.4) D,

h ₁ = (0.8 ÷ 0.9) H,

h ₂ = (0.45 ÷ 0.55) H,

d = (0.07 ÷ 0.08) D,

_Holes S = (0.2 ÷ 0.3) πD ^2/4,

d _resp = (0.1 ÷ 0.2) D

determined experimentally from the condition of ensuring the best mixing of liquids and powders with a liquid.

5. The implementation of the rod with the working body with the ability to move in the tank in horizontal and vertical directions provides uniform mixing of liquids or powders with liquid in a large volume tank.

An example implementation of the invention

The proposed device (Fig. 2, Fig. 3) consists of three perforated disks 2-4 made of stainless steel with a thickness of 3 mm, fixed by welding to the rod 1 at the centers of the disks. The distance between the discs is 30 mm, from the lower end of the rod to the lower disc 30 mm. Each disk has holes with a diameter of 10 mm. Four pins with a diameter of 6 mm and a height of 25 mm are welded around the periphery of the disks through an angle of 90 °. The central disk of the same design is mounted on the rod with the displacement of the pins at an angle of 45 °. An upper disk of a similar design is mounted on the rod 4 with a displacement of the pins by an angle of 45 ° relative to the central disk. The length of the rod of the device (500 ÷ 600) mm. As a source of rotation and longitudinal vibrations of the rod, a perforator of the DU-750 ER brand was used.

To select the structural and operational characteristics of the device, a series of experiments was conducted on mixing glass balls with a diameter of 1 mm in a 5 l water tank using the inventive device. With the optimal choice of characteristics, uniform mixing of the balls in the tank was achieved for a time of not more than 10 s (Fig. 4).

Similar experiments were carried out for aluminum nitride nanoparticles with a diameter of 50 nm, introduced into the electrolyte solution. With optimal characteristics of the device, complete mixing was achieved over a period of not more than 35 s.

The effectiveness of the inventive device is confirmed by experiments on mixing nanoparticles of aluminum nitride in the molten magnesium alloy ML 12 in a filling tank (ladle) of 10 l. A metallographic analysis of the obtained composite material showed a uniform distribution of reinforcing particles throughout the volume of the matrix metal (Fig. 5).

Thus, from the above example it follows that the proposed device ensures the achievement of the technical result of the invention - the most complete mixing of different liquids and powders in a liquid to obtain a uniform composition and a uniform distribution of solid particles.

Information sources

1. Patent No. 1349057 of the Russian Federation, IPC B01F 5/00. Hydrodynamic mixer / Pishchenko LI, publ. 10/10/1997.

2. Patent No. 2137535 of the Russian Federation, IPC B01F 3/12, B01F 13/02. A device for mixing particles of a substance with a liquid / Ohman S., Bringfors N., Johansson L.; publ. 09/20/1999.

3. Patent No. 2342984 of the Russian Federation, IPC B01F 3/12, B82B 3/00. The mixer of nanoparticles with liquids / Sheludyakov EP; publ. 01/10/2009.

4. Patent No. 2247289 of the Russian Federation, IPC F27D 23/04, F27D 1/16, C22B 9/05, C21C 1/00, C21C 7/00, C21C 5/46. A method of protection against erosion, oxidation and corrosion of the surface, a device for processing molten metal, a rotating stirrer of a device for cleaning molten metal and a method for processing molten metal / Holtz K. Jacqueline, Duru Jean-Jacques; publ. 02/27/2005.

5. Patent No. 2288029 of the Russian Federation, IPC B01F 7/18, A47J 43/04. Mixer / Babaev A.K., Terentyev S.A .; publ. 11/27/2006.

Claims (4)

1. A device for mixing liquids and powders with a liquid in the tank, containing a rod with a working body fixed at one end with the possibility of its rotation and longitudinal oscillatory movement, characterized in that the working body is made in the form of three disks rigidly fixed to the rod at the same distance n from each other, and n cylindrical pins aligned with their free ends toward the central disk and offset relative to each other the surface of the disk at the same angle α = 360 ° / n, and on each of the surfaces of the central disk there are coaxially n cylindrical pins displaced relative to the pins of the extreme disks by an angle α / 2, and through holes are made on each of the disks evenly spaced along them surface, while the rotation speed of the rod is (500 ÷ 2700) rpm, the frequency of its longitudinal vibrations is (5 ÷ 30) Hz, and the amplitude of the vibrations is not less than 0.8 cm, and the distance between the disks, the height and diameter of the pins, the total area hole th in the disk and the diameter defined by the relationships: H = (0.3 ÷ 0.4) D, d = (0.07 ÷ 0.08) D, h ₁ = (0.8 ÷ 0.9) H, _Holes S = (0.2 ÷ 0.3) πD ^2/4, h ₂ = (0.45 ÷ 0.55) H, d _resp = (0.1 ÷ 0.2) D, where H is the distance between the disks; D is the diameter of the disks; h ₁ - the height of the pins mounted on the extreme disks; h ₂ - the height of the pins mounted on the central disk; d is the diameter of the pins; _Holes S - total area of the holes in the disc; d _holes - hole diameter. 2. The device according to p. 1, characterized in that the rod with the working body is made with the possibility of movement in the tank in horizontal and vertical directions.

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