WO2008004907A2

WO2008004907A2 - Device for mixing liquid and powder materials

Info

Publication number: WO2008004907A2
Application number: PCT/RU2007/000315
Authority: WO
Inventors: Stanislav Afanasjevich Gerasimenko; Sergey Vladimirovich Golovchenko
Original assignee: Gerasimenko Stanislav Afanasje; Golovchenko Sergey Vladimirovi
Priority date: 2006-07-05
Filing date: 2007-06-13
Publication date: 2008-01-10
Also published as: WO2008004907A3; RU2313383C1

Abstract

The invention relates to a device for mixing active mediums, in particular, powder and liquid materials. The device contains an enclosure (2), first (4) and second (5) shafts, first (12) and second (15) loading means of powder and liquid materials, powder material stream shaper, liquid material stream shaper and means (20) for collecting and unloading of the resulting end product. The shafts are mounted to allow rotation with different speeds. The powder material stream shaper includes a plate (9) having blades (11) which are placed radially along spiral trajectories and are fixed on the plate by means of springs to allow vibration along the plate's plane. The device additionally contains a closed circular chamber (18) surrounding the baffle for creation of water or steam veil and a screen (13) rigidly fixed on the enclosure above the plate. The invention ensures highly effective mixing with allowing to receive a resulting end product without lumps and interstice.

Description

MIXING DEVICE FOR LIQUID AND POWDER MATERIALS

1. Field of invention

The invention relates to techniques for mixing mobile media of different densities and in various states, and more particularly, to a device for mixing liquid and powder materials, as well as for producing highly homogenized materials, and can be used in the preparation of mixtures and highly homogenized materials in chemical, food, pharmaceutical , construction and other industries and agriculture.

2. The prior art

When mixing various media, especially those containing components in different phase states, it is important to obtain a product with the maximum uniform consistency, in which there would be no voids or clots of unmixed fractions. The presence of such sites significantly reduces the quality of the product and can even lead to the destruction of products obtained from it. Therefore, much attention is paid to the problem of ensuring high-quality mixing. Methods and devices are provided. the use of various techniques: complex mechanical effects, the creation of certain conditions for the mixing and interaction of components, and more, which together are designed to provide an optimal final product in consistency.

The patent of the Russian Federation N ° 2121870 describes the mixing of powdered and granular materials that occurs inside a parabolic rotor rotating around its axis. Mixed materials are fed into the rotor cavity, made in the form of a bowl having a parabolic shape in cross section. When the rotor rotates, the particles of materials are given acceleration and movement along certain trajectories, depending on the parameters and speed of the rotor and the characteristics of the mixed materials. The motion paths repeatedly collide and cross, and the mixture is mixed. Thus, the already prepared mixture enters the rotor edge, which, under the action of centrifugal force, is discharged from the rotor surface and is discharged. The disadvantage of this method is the inability to control mixing and obtaining the resulting product of a heterogeneous structure. It contains lumps of remaining unmixed materials and granular components. From the USSR author's certificate of NAZOOZO, a continuous mixer is known for the preparation of a finely dispersed suspension of powder and liquid components at the mixing stage. The mixer comprises a housing with a conical bottom rotated by an electric motor. A shaft rotatable from the drive is installed along the central axis of the housing, on which a mixing body, disk, and movable dropping knives are mounted. The liquid component is supplied to the rotating bottom and forms a film moving to the edge on its surface, and the powder component enters the disk, from where it is sprayed into the film due to centrifugal force. The resulting mixture is discarded onto a rotating mixing body, from where it flows by gravity or with knives into the discharge pipes. The disadvantage of this mixer is that the process of meeting the components occurs on the surface of the bottom, which does not provide a homogeneous structure of the mixture without lumps, voids or granular formations. Moreover, the mixing process itself is highly energy-consuming, in particular, due to the need to drop the mixture adhering to the walls of the mixing organ using knives. It is known that cleaning knives should work at low speeds (up to 60-300 rpm). Work at high speeds (more than ZOOOob / min) entails enormous energy costs. Thus, the design of the device is complex, energy-intensive and contains a large number of additional elements, which entails an increase in the cost of its operation, and, consequently, an increase in the cost of production of the mixtures themselves.

The objective of the invention is to remedy these disadvantages, increase, intensify mixing and ensure optimization of energy consumption and process control, improve the quality of the finished product and create a simple in design and inexpensive device for its production.

Dry or wet mixing in order to obtain a homogeneous mixture is a complex technological task. In particular, a technology is known where interacting directed component flows are involved in mixing processes, one of which is a stream scattered by a rotating rotor, and the other flows down the wall of the mixing tank under the influence of gravity. The main role here is played by the centrifugal and gravitational components of the flow displacement vector. However, the centrifugal component of the flow displacement vector takes place only in the rotor. As soon as the rotor leaves the flow, the centrifugal component disappears due to the universal law of physics on rectilinear and uniform motion, but the gravitational component appears. The flow, therefore, becomes virtually uncontrollable. On the other hand, along the wall capacity, the stream flows only under the influence of gravity, and the centrifugal component is absent. When mixing the streams of components on the walls of the tank (in this case, turbulence is known to be minimal and the mixing efficiency is low) only the gravitational component remains, i.e. a mixture of components, whatever its quality, slides along the wall to the bottom. They are trying to improve the quality of the mixture by installing scrapers, mixers, etc. Naturally, such technical solutions complicate the design and do not make it possible to obtain a high-quality target product.

Therefore, it is necessary to effectively influence the flows of components, in particular, to provide pre-mixing of the powder material or pre-mixing and activation, or additionally grinding, and to control the mixing process all the way from feeding to the apparatus and to unloading the target product.

3. The invention

The problem is solved in that in the known device for mixing powder and liquid materials containing a housing, the first and second shafts passing through its central axis, connected with the corresponding first and second drives, the first and second means for loading powder and liquid materials, means for forming a powder material flow in the form of a plate rigidly mounted on the first shaft and a deflector in the form of a truncated cone that faces the plate with a large base facing downwards; means for forming a flow and the liquid material in the form of a drum mounted on a second shaft under the means for forming a powder material stream, and means for collecting and unloading the resulting product, in accordance with the invention, the shafts are rotatably mounted at different speeds, the means for forming a powder material stream contains the impeller, the blades of which are essentially orthogonal to the plane of the plate, are arranged radially along spiral paths and mounted on the plate by means of springs with possible Stu vibration along the plane of the plate. This embodiment of the blades allows them to take the necessary, adaptive curvature with changes in the flow rate of the powdery material, thereby facilitating the flow of the powder and drastically reducing energy consumption for friction.

Preferably, the device further comprises an enclosed circular chamber surrounding the deflector from the outside, connected to a source of water or steam and configured to create a water or steam curtain directed into side of the drum. To do this, for example, it is possible to perform exhaust nozzles on the surface of the circular chamber facing the central axis, through which the vapor or liquid in the form of small droplets, which form a water or steam curtain, is released.

In this case, the circular camera is installed not lower than the edge of the cone of the deflector.

It is desirable that the deflector be rigidly attached to the body so that the lower edge of the cone of the deflector is no higher than the level of installation of the plate on the first shaft.

The device may be further provided with a screen mounted, for example, spring-loaded in the housing above the rotation means. Such a screen prevents the mass escape of particles of powder material from the plate to the moment of reaching its edge, which, on the one hand, ensures its more full involvement in the mixing process, and, on the other hand, avoids the deposition of small particles in the form of dust on structural elements, which interferes with normal operation or may even cause the device to malfunction.

4. Brief Description of the Drawings

Further, the invention is illustrated using one of the possible, but not exhaustive, options for its implementation, shown in the drawings, in which:

FIG. 1 is a schematic front view of a device (vertical section); embodiment with a two-cavity drum;

5. An example of carrying out the invention

In FIG. 1 shows a device 1 for mixing powder and liquid materials. The device comprises a housing 2 with a working volume of 3 and passing along its central axis of the first shaft 4 and the second shaft 5, driven into rotation, respectively, from the first drive 6 and the second drive 7. The shafts 4 and 5 are mounted coaxially and connected in any known manner to the corresponding drives 6 and 7 so that they can have different speeds and directions of rotation. In this embodiment, in particular, the mutual twisting of the flows by the tangential components of the rotational speeds of the accelerators is compensated.

On the first shaft 4, rotation means 8 is arranged, comprising a plate 9 open upwardly mounted on the first shaft 4 and an impeller 10 located above it, which is a series of blades 11 extending radially along the spiral paths, the working plane of which is essentially orthogonal the plane of the plate 9. The dimensions of the plate are selected depending on the desired performance, i.e. the desired number of particles to be scattered: the larger the radius of the plate, the greater the number of powder particles will leave simultaneously from its surface while maintaining the same thickness of the powder layer, and also depending on the speed with which the particles should fly out from the surface of the plate. This speed, in turn, should not exceed the level after which turbulent air flows arise between the plate and the deflector, causing undesirable entrainment of the smallest and lightest particles, i.e. dusting. Usually choose a speed of 2 - 8m / s.

Above the rotation means 8, a first loading means 12 is arranged for supplying the powder material to the rotating means 8. In this embodiment, a screen 13 is installed between the rotating means 8 and the first loading means 12 to prevent powder material from flying out of the zone of the rotating means 8.

On the second shaft 5, a two-cavity drum 14 is mounted rotatably with the shaft 5, above which there is a second loading means 15 for supplying liquid material to the drum. The dimensions of the drum are determined by the desired ratio of interacting droplets of liquid with particles of powder material, which reaches 100%.

In the upper part of the device inside the housing 1 is installed a deflector 16, made in the form of a truncated cone. The deflector 16 is placed with a large base down so that the edges of its smaller base are fastened to the housing, the walls surround the rotation means 8, and the edge 17 of the larger base extends in space below the level of attachment of the plate 9 to the shaft 4.

In the working volume 3, at the level not lower than the edge 17, an annular closed chamber 18 is installed with output nozzles 19 directed towards the central axis of the housing. The chamber 18 is connected to an additional source of liquid or steam material not shown here. Liquid material or steam leaving the nozzles 19 creates an additional annular region of the atomized liquid material, for example, in the form of a droplet or vapor curtain. The installation radius Rl of the annular chamber 18 relative to the central axis is greater than the radius R2 of the larger base of the deflector 1 b. In the lower part of the housing there are any known means 20 for collecting and unloading the target product.

The device operates as follows. Drives 6 and 7 rotate the shafts 4 and 5 and, accordingly, the rotation means 8 and the drum 14. Powder material from the first means of loading 12 enters a rotating plate 9, on which particles of material are accelerated, mixed and frayed with the activation of the surface of each particle. The impeller 10 located in the region of the recess of the plate 9 contributes to the specified process, and also prevents the grouping and stagnation of the powder material in the region of the central axis. The screen 13 located above the plate 9 prevents the particles from flying upward, returning them to the region of accelerated centrifugal motion created by the plate 9. Upon acquisition of centrifugal acceleration, the particles are sprayed from the plate and hit the deflector wall, resulting in disaggregation and further activation of the particle surface, as well as the formation of the necessary direction of movement of the flow of powder material. After the impact, the particles, while retaining some tangential component of the spraying speed, fall in the form of a closed powder stream "pulled" down. The liquid material supplied through the second loading means 15 to the rotating drum 14 acquires a film state due to centrifugal forces, which is sprayed from the drum in the form of a dispersed liquid stream consisting of small droplets. The sprayed liquid stream is introduced into the stream of activated powder material, as a result of which they are intensively mixed. Powder particles bound to the liquid material fall down on the bottom of the device. The remaining undisturbed minor part of the particles of the powder material is additionally exposed to a water or steam curtain formed by the nozzles 19 of the annular chamber 18, thereby achieving higher mixing efficiency. Obtained after mixing, the target product is collected in the lower part of the body, if required, is additionally mixed using known mechanical means and unloaded from the device by any known methods and devices conventionally shown as unloading means 20.

It should be borne in mind that the given embodiment of the invention is one of the others possible, in which other design solutions can be used in accordance with the spirit and idea of the invention.

Claims

CLAIM

1. A device for mixing powder and liquid materials, comprising a housing, first and second shafts passing through its central axis, connected to respective first and second drives, first and second means for loading powder and liquid materials, means for forming a flow of powder material in the form of a rigid installed on the first shaft of the plate and the deflector in the form of a truncated cone, facing a large base downward, surrounding the plate, means for forming a flow of liquid material in the form of a drum, installed on the second shaft under the means for forming a flow of powder material, and means for collecting and unloading the resulting product, characterized in that the shafts are mounted for rotation at different speeds, the means for forming a flow of powder material contains an impeller placed above the plate, the blades of which are essentially orthogonal to the plane of the plate, placed radially along spiral paths and mounted on the plate by means of springs with the possibility of vibration along the plane of the plate.

2. The device according to p. 1, characterized in that it further comprises a closed circular chamber surrounding the deflector, configured to create a water or steam curtain, directed towards the drum.

3. The device according to p. 2, characterized in that the circular camera is installed not lower than the edge of the cone of the deflector.

4. The device according to p. 1, characterized in that the deflector is rigidly attached to the housing so that the lower edge of the cone of the deflector is not higher than the level of installation of the plate on the first shaft.

5. The device according to p. 1, characterized in that it further comprises a screen rigidly mounted in the housing above the plate.