Gravity mixer

FIELD: mechanics.

SUBSTANCE: gravity mixer consists of a cylinder-shaped taper-bottomed body with feed and discharge nipples. On centre inside the body there is a vertical pipe conduit mounted with tangentially hydraulic nozzles arranged at a specified spacing along it. Between the pipe conduit and the body wall there is a onefold discontinuous tape helix rigidly fixed. Under the last but one coil of the tape helix there is a slanted sieve bottom with a rubber compensator element positioned. Under the sieve bottom there is hammer installed to provide for periodical application of impact onto the sieve bottom rubber compensator element. Additionally the gravity mixer is equipped with a bucket conveyor for metal balls upward transportation. A slanted conduit connects the bucket conveyor bottom part to that of the gravity mixer (immediately at the lower edge of the slanted sieve bottom) and the bucket conveyor top part - to the gravity mixer lid.

EFFECT: enhanced energy efficiency of the mixing process, reduced specific energy consumption and improved operational reliability of the gravity mixer.

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The invention relates to food processing and can be used in production lines of food mixtures and concentrates.

The closest in technical essence and the achieved effect is gravitational mixer [Ostrikov A.N. and other Processes and devices of food manufactures. - SPb.: GIORD, KN. 1 - 2007. - 704 S.], comprising a cylindrical housing with fittings (elbows) and conical bottom. Within the cylindrical body mounted one above the other inclined trays. Blend components are fed into the mixer in a continuous flow through the fitting. The mixture of initial components after meeting with the surface of the tray is rebuilt: tray material slides with a thin layer. The individual components are mixed at the moment of layers flowing from the first two trays, with their uneven movement on subsequent trays, and Persiani from a tray on the tray.

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

An object of the invention is to increase the efficiency of the mixing process, the reduction of specific energy consumption for carrying out the mixing process and improving the reliability of the gravitational mixer.

The goal of the project izopet the tion is achieved by what in the gravitational mixer containing cylindrical body with a conical bottom, the pipes for loading and unloading product, what's new is that inside the center there is a vertical pipeline with a certain step are tangentially hydraulic nozzles, between the pipeline and the casing is rigidly fixed single broken tape helix, which with a certain step installed vortex generators, which are blades Limehouse form, under the last round of intermittent tape helix is inclined sieve bottom with rubber expansion joint, on the inner surface of the housing of the mixer under the sieve plate has a hammer with the possibility of periodic impact on rubber compensator sieve bottoms, with a gravity mixer is further provided with a bucket conveyor for lifting metal balls, the size of the buckets of the conveyor is selected to provide a steady load of each bucket with a metal ball, the lower portion of the bucket conveyor are connected by a sloped pipe with the bottom part of the gravitational mixer at the lower edge of the inclined sieve plate, and its upper part is inclined pipe with cap gravity mixer.

Figure 1 ol is dostavleno three-dimensional image of the gravitational mixer, figure 2 - cross section of a gravity mixer; figure 3 is a planar representation of the gravitational mixer.

Gravity mixer (figure 1, 2 and 3) includes a cylindrical housing 1 with the sockets for input of loose components 3 and discharging the mixture 10, the nozzle 16 to exhaust air. Inside the housing 1 is a vertical pipe 2, on the outer surface of which a certain step are tangentially hydraulic nozzle 9 and is rigidly fixed single broken tape helix 5 with an interval of gaps in 3/4 turn. The angle of the coils single broken tape helix 5 depends on the humidity of the raw product, adhesion properties, particle size distribution and surface condition of the helix 5. Helix 5 with a certain step installed vortex generators 6, representing blades Limehouse forms to ensure swirling motion of the mixture components. In the lower part of the housing 1 below the last round broken tape helix 5 of the mixer is inclined sieve plate 7 with a rubber compensator 15. On the inner surface of the housing 1 of the mixer under the sieve plate 7 is installed hammer 8 with the possibility of periodic impact on rubber compensator 15 sieve plate 7.

Gravity mixer additionally nebgen bucket conveyor 12 for lifting metal balls 13, which serve as a device for intensive mixing and eliminating stagnant zones.

The lower part of the bucket conveyor 12 are connected by a sloped line 14 with the bottom part of the gravitational mixer, and an outlet opening in the housing 1 of the mixer, connecting with a sloped pipe 14, is located at the level of the lower edge of the inclined sieve plate 7. The upper part of the bucket conveyor 12 are connected by a sloped pipe 11 with a lid gravity mixer. Holes in sicovam plate 7 is made such to ensure that the spilling of all fractions of the mixture, i.e. their size should be larger than the largest components of the mixture, but less than the diameter metal balls 13. The mixture wakes up through the sieve plate 7, enters the tapered portion 4 of the mixer, and from there into the discharge pipe 10 and on to further processing.

Metal balls 13, rolling on the surface of the inclined sieve plate 7, through the hole in the housing 1 of the mixer is directed in an inclined pipe 14 and into the buckets of the conveyor 12. The size of the bucket conveyor 12 is selected such as to provide a steady load of each bucket with a metal ball 13.

In parallel with the feedstock is supplied with metal balls 13 on the pipeline 11 moved out of the mixer by using the bucket conveyor 12, they fall out of the socket 14.

On the pipeline 2 tangentially arranged hydraulic nozzles 9, of which facing the compressed air additionally mixing a granular mixture components. In the top cover of the gravitational mixer is a pipe 16, which is designed for the removal of exhaust air.

Gravity mixer (figure 1, 2 and 3) works as follows.

Loose components defined portions are received in the receiving pipe 3, which fall on the inclined surface of the single coils broken tape helix 5 with an interval of gaps in 3/4 turn. Simultaneously, the drive of the bucket conveyor 12, the buckets of which cover turn the balls 13 of the inclined pipe 14 and up. In the upper part of the conveyor 12 buckets tip over, and the balls 13 on the inclined pipe 11 serves in a gravity mixer on an inclined surface coils single broken tape helix 5, where it is mixed with bulk components. Under the action of gravitational forces, a mixture of loose components and metal balls 13 on one tape helix 5 moves down. The presence of turbulizer 6, is rigidly fixed with a certain step in the spiral 5, allows you to turboservice directed movement of the mixture and stirring vigorously bulk comp is the components. Parisiana from the upstream coil to the downstream spiral turn 5 additionally provides not only the mixing of the product, but also gives a uniformly accelerated movement of the mixture along the surface of the turns of the spiral belt 5. In a vertical pipe 2 serves the air, leaving tangentially located hydraulic nozzles 9, evenly and optionally mixing the mixture of dry components. The exhaust air passes through the pipe 16 located in the top cover of the gravitational mixer.

From theory it is known [the Processes and devices of food manufactures: Textbook. for high schools: 2 kN. / [Anistratov, Yevgrafovich, Havo etc.]: Ed. Anistratov - KN. 1. - SPb.: GIORD, 2007. - 704 S. - S-639.], the mixing process is composed of three elementary processes:

- convective mixing - moving group of adjacent particles from one place mixture in another implementation, the sliding layers;

- diffusive mixing is a gradual redistribution of the particles through svezheubrannoy the interface;

- segregation of particles to the concentration of particles of similar mass and size, in the appropriate places of the mixer under the action of inertial and gravitational forces.

If the first two processes contribute to improving the quality of the mixture, the latter prevents this. In the mixer od is vremenno run all three processes, but their influence in different periods of mixing are different. The process of convective mixing in the first moments comes with great speed, the speed of the process almost does not depend on the physico-mechanical properties of the mixture. The main effect on the speed of the mixing process at this moment of time has the character of the flow of particles, which is determined by structural parameters of the mixer.

Once the components will be mainly distributed in the working volume of the mixer, the processes of convective and diffusive mixing become, by their impact on the overall mixing process, comparable. At some point, the process of diffusion mixing becomes predominant.

Then a significant influence on the process begins to provide segregation of particles. At some point in time, these processes can be balanced, and then further mixing is meaningless, and the process has to be completed.

The duration of the diffusion mixing depends on the physico-mechanical properties of the mixture, of which the most important are the particle size, density, shape and nature of the surface of the particles, their moisture content and flowability. The closer the components of the above-mentioned properties, the more effective their mixing. The greater the difference in size, density contributes to the segregation of particles. Has the value of the number of components. With their increase in the share of each is reduced and the mixing process is hampered.

Such use of combined exposure to mixture of dry components, namely:

1) slip of the mixture components on the surface of the turns of the helix 5,

2) provide a vortex flow of the mixture components energizers 6 Limehouse form,

3) pouring the mixture components from the top of the coils on the bottom coils of the helix 5;

4) intensive europerelevant flow of air from the nozzles 9 promotes an intensive course of convective and diffusive mixing, but prevents segregation of the particles. This greatly increases the efficiency of the process of the mixing of dry components.

The mixture falls on the inclined sieve plate 7 and, sliding on it, passes through the holes in the conical portion 4 of the mixer. To prevent caking of the mixture on the surface of the inclined sieve plate 7 is provided in the periodic rotation of the hammer 8, which strikes the rubber expansion joint 15, the transmitting vibrations sitonomy the bottom 7.

Metal balls 13 through the opening in the housing 1 into the pipe 14. The mixture from the bottom of the conical part 4 of the mixer is poured into the discharge pipe 10 and then for further processing.

Compared with the prototype of the proposed gravity of the mixture is spruce has the following advantages:

- improving the quality of the mixture of the product;

- improving the efficiency of the mixing process due to the combined use of slip of the mixture components on the surface of the coils, provide a vortex flow of the mixture components energizers Limehouse forms, pouring the mixture components from the top of the coils on the bottom coils of the spiral and intensive europerelevant flow of air from the nozzles;

- reduction of specific energy consumption for carrying out the mixing process by eliminating the energy consumption for the movement of the operating parts (blades, coils, etc.);

extension of application due to the achieved universalization of the mechanism of the uniform mixing;

- improve the operational reliability of the gravity of the mixer due to the lack of mobile working bodies.

Gravity mixer containing cylindrical body with a conical bottom, the pipes for loading and unloading product, characterized in that inside the center there is a vertical pipeline with a certain step are tangentially hydraulic nozzles, between the pipeline and the casing is rigidly fixed single broken tape helix, which with a certain step installed vortex generators, which are blades Limehouse the th form under the last round of intermittent tape helix is inclined sieve bottom with rubber expansion joint, on the inner surface of the housing of the mixer under the sieve plate has a hammer with the possibility of periodic impact on rubber compensator sieve bottom, with a gravity mixer is further provided with a bucket conveyor for lifting metal balls, the size of the buckets of the conveyor is selected to provide a steady load of each bucket with a metal ball, the lower portion of the bucket conveyor are connected by a sloped pipe with the bottom part of the gravitational mixer at the lower edge of the inclined sieve plate, and its upper part is inclined pipe with cap gravity mixer.