RU2411988C2 - Loose product mixer - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to mixing equipment. Stationary housing accommodates revolving screw. Screw shaft supports swirling vanes. Two aligned conical chambers are arranged outside the housing to rotate in opposite directions. R.H. walls of every conical chamber are fixed to allow loading branch pipe to pass there through to feed product into smaller conical chamber. Inner surface of smaller chamber is provided with bins and screws coils are arranged on its outer surface. Housing end has opening for transfer of product into smaller conical chamber. The end of smaller conical chamber has discharge oval holes to transfer the product into larger conical chamber. Larger chamber end has radial oval holes to discharge finished mix from the mixer. Screw and both chambers are driven by one drive via gear transmission system.

EFFECT: higher efficiency of mixing, reduced power consumption and expanded applications.

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Description

The invention relates to equipment for mixing bulk materials and can be used in the production lines of animal feed, food mixtures, food concentrates, etc.

The closest in technical essence and the achieved effect is a drum mixer [Ostrikov A.N. and other processes and apparatuses of food production. - SPb .: GIORD, Prince. 1. - 2007. - 633 S.], including a cylindrical body with fittings (nozzles) and a conical bottom. Inside the cylindrical body mounted on top of each other inclined trays. The components to be mixed are fed into the mixer in a continuous stream through the nozzles. After meeting the surface of the tray, the mixture of the starting components is rebuilt: the material slides along the tray in a thin layer. The individual components are mixed at the moment of meeting the layers flowing down from the first two trays, in case of their uneven movement on subsequent trays and pouring from tray to tray.

The disadvantage of this mixer is the low efficiency of the mixing process, the possibility of the formation of stagnant zones, which limits its scope.

An object of the invention is to increase the efficiency of the mixing process, reduce specific energy consumption for the mixing process and expand the scope due to the achieved universalization of the uniform mixing mechanism.

The object of the invention is achieved by the fact that inside the stationary housing there is a rotating screw, on the surface of the shaft of which turbulizing blades are installed, two coaxially mounted conical chambers are arranged outside of the mixer body, made to rotate in opposite directions, and the right walls of each conical chamber are made stationary and through them passes the loading pipe, feeding the product into a smaller cone-shaped chamber, on the inner surface less buckets are installed for it in the conical chamber, and screw turns are installed on its outer surface, a hole is made at the end of the housing for pouring the product into a smaller conical chamber, at the end of the smaller conical chamber there are radially located discharge oval holes for pouring the product into the large conical chamber, at the end of the larger the conical chamber is also made radially arranged discharge oval holes for unloading the finished mixture from the mixer, and the rotation of the screw and cone-shaped kame p is carried out from a single drive through a gear system.

Figure 1 presents a three-dimensional image of the mixer for bulk products, figure 2 is a planar image of the mixer for bulk products.

The mixer for bulk products consists of four loading nozzles 1, which are located on a fixed housing 2, a screw 3 with turbulizing blades 4, two bearing bearings 6 and a gear 7. Outside of the mixer housing 2 there are two coaxially mounted conical chambers 8 and 12, made with the possibility of rotation in opposite directions. At the end of the housing 1 there is an unloading hole 5 for pouring the product into a smaller conical chamber 8 (figure 1).

The screw 3 is driven into rotation by a gear motor 14 using gears 15, 7 and a pinion gear 16.

Buckets 9 are installed on the inner surface of the smaller conical chamber 8, and the screw 11 turns are installed on its outer surface. At the end of the smaller conical chamber 8 there are radially located discharge oval holes 10 for pouring the product into the large conical chamber 12 (Fig. 2).

On the right stationary wall of the chamber 12 is a pipe 22 for loading the components of the mixture. A gear 20 is fixed on the left movable wall of the chamber 12. A smaller cone-shaped chamber 8 is driven by a gear motor 14 using a gear 15, satellite gears 16 and 21 located on the shaft, which is fixed in the bearing bearings 17, and the gear 20. The wheel 20 with internal gearing is rigidly fixed on the left side wall of the chamber 8.

On the left wall of the chamber 12, a gear wheel 19 is fixed with internal gearing. The large cone-shaped chamber 12 is rotatable: for this, the cone-shaped body of the chamber 12 is brought into rotation by means of gears-satellites 21 and 16, gear wheel 15 by a gear motor 14. the larger conical chamber 12 is made radially located discharge oval holes 13 for unloading the finished mixture from the mixer.

The mixer is mounted on supports 18.

The mixer for bulk products (figure 1, 2) works as follows.

The gear motor 14 is turned on, which with the help of gears 15, 7 and gears-satellites 16 and 21 simultaneously drives the screw 3 and two coaxially mounted conical chambers 8 and 12, and the screw 3 and the smaller conical chamber 8 rotate clockwise, and the large cone-shaped chamber 12 rotates counterclockwise.

Various components of the four loading nozzles 1 enter the loading zone of the housing 2, where they are captured by a rotating screw 3 with turbulizing blades 4. The shape, size and location of the turbulizing blades 4 together with the rotating screw 3 give the components of the mixture a turbulent movement directed along the axis of the screw 3 in the direction of the discharge opening 5. Intensive mixing of bulk components, differing in structural and mechanical properties and particle size distribution, is provided due to differences frictional forces between the blend components, the inner surface of the housing 2 and auger 3. Reaching the end surface of the housing 2, the mixture components are interspersed through the discharge port 5 in the lower conical chamber 8.

At the same time, other components are fed through the loading pipe 22 into a smaller conical chamber 8, where they are mixed with the components of the mixture coming from the stationary body 2 through the discharge opening 5 into the chamber 8. Then all these components of the mixture are moved from the loading along the inner inclined surface of the rotating conical camera 8 holes 5 using buckets 9 installed with a certain step, intensively mixing, to the radially located unloading oval holes 10 for pouring mixture and in a large conical chamber 12.

Then, the mixture through the oval discharge openings 10 enters a large conical chamber 12, in which effective mixing is achieved by the combined action of clockwise rotating coils 11 on the outer surface of the smaller conical chamber 8 and by rotating the casing of the conical chamber 12 counterclockwise. This effect provides uniform and additional mixing of bulk components. The finished mixture is continuously unloaded through the radially located discharge oval holes 13.

From theory it is known [Processes and apparatuses of food production: Textbook. for universities: In 2 kn. / A.N. Ostrikov, Yu.V. Krasovitsky, A.A.Shevtsov et al.: Ed. A.N. Ostrikova. - Prince 1. - St. Petersburg .: GIORD, 2007. - S.598-639.] That the mixing process consists of three elementary processes:

- convective mixing - moving a group of adjacent particles from one place of the mixture to another by incorporation, sliding layers;

- diffusion mixing - the gradual redistribution of particles through a freshly formed interface;

- particle segregation - the concentration of particles having a similar mass and size in the corresponding places of the mixer under the influence of inertial, gravitational forces.

If the first two processes contribute to improving the quality of the mixture, then the latter prevents this. In the mixer, all three processes occur simultaneously, but their influence in different periods of mixing is not the same. The process of convective mixing in the first moments proceeds at a high speed, while the speed of the process is almost independent of the physicomechanical properties of the mixture. The main influence on the speed of the mixing process at this point in time is exerted by the nature of the movement of particle flows, which is determined by the design parameters of the mixer.

After the components are mainly distributed over the working volume of the mixer, the processes of convective and diffusion mixing become, by their influence on the general mixing process, comparable. Starting at some point, the diffusion mixing process becomes dominant.

Then, particle segregation begins to have a significant effect on the process. At some point in time, these processes can be balanced, after which further mixing becomes meaningless, and the process should be completed.

The duration of diffusion mixing also depends on the physicomechanical properties of the mixture, of which the particle size distribution, density, shape and nature of the surface of the particles, their moisture content and flowability are of the greatest importance. The closer the components have these properties, the more effective their mixing. A greater difference in size, density promotes particle segregation. The number of components also matters. With their increase, the proportion of each decreases, and the mixing process becomes more difficult.

This use of combined effects on a mixture of bulk components, namely:

1) sliding a mixture of components on the surface of the turns of the screw 3;

2) ensuring the vortex motion of the flow of the mixture of components turbulent blades 4;

3) mixing the moving flow of the mixture with buckets 9;

4) pouring the mixture of components from the cylindrical inner section of the housing 2 into a conical chamber 8 and then into a large conical chamber 12;

promotes intensive convection and diffusion mixing, but prevents particle segregation. This significantly increases the efficiency of the process of mixing bulk components.

The proposed mixer for bulk products has the following advantages:

- improving the efficiency of the mixing process through the use of original design turbulizing blades 4, buckets 9 and coaxially mounted conical chambers 8 and 12; and also due to the separate management of the mixture components through the nozzles 1 and other components through the nozzle 22;

- reduction of specific energy consumption for the mixing process by minimizing the duration of the mixing process and combining different in intensity mixing methods;

- expanding the scope due to the achieved universalization of the uniform mixing mechanism.

Claims (1)

A mixer for bulk products, comprising a housing, an unloading chamber, gears with a tapered bottom, nozzles for loading and unloading the product, characterized in that there is a rotating auger inside the stationary housing, on the surface of the shaft of which turbulizing blades are installed, two coaxially mounted conical chambers made to rotate in opposite directions, the right walls of each cone-shaped chamber made motionless and through them passes a loading nozzle feeding the product into a smaller cone-shaped chamber, buckets are installed on the inner surface of the smaller cone-shaped chamber, and screw turns are located on its outer surface, a hole is made at the end of the housing for pouring the product into the smaller cone-shaped chamber, at the end of the smaller cone-shaped chamber there are radially unloading oval openings for pouring the product into a large cone-shaped chamber; at the end of a larger cone-shaped chamber, radially located discharge ovums are also made flax openings for discharging the finished mixture from the mixer, and the rotation of the screw and the tapered chambers provided from a single drive via a system of gears.

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