RU136741U1 - CAVITATION TYPE MIXER FOR LIQUID FOOD MEDIA - Google Patents

Abstract

A cavitation-type mixer for liquid food media, containing a working chamber, a mixing nozzle element fixed at the chamber inlet, an outlet pipe in the form of a diffuser located at the chamber outlet coaxially with it and the mixing element, and a nozzle for supplying an additional mixture component, characterized in that the mixing element made in the form of a single-jet nozzle, inside which a streamlined flat insert is installed along the axis along its entire length, the thickness of which h at the nozzle exit is 0.1D, where D is the outlet diameter of the nozzle, and the pointed end of which is located at the inlet to the mixer.

Description

The utility model relates to the food industry, namely to technological plants and food production lines for producing food emulsions by cavitation treatment of a liquid mixture stream.

The widespread use of cavitation phenomena is due to the need for such technological operations as mixing, dispersion, heat and mass transfer, etc. Currently, cavitation technologies give excellent results in the conversion of gaseous, solid, and liquid media. These technologies are used to prepare mixtures resistant to delamination (also for mixing difficult to mix or immiscible media), homogeneous solutions, emulsions, suspensions and dispersions from various products, to activate enzymes and accelerate processes by supporting catalytic reactions, to treat wastewater, and for water purification in water treatment systems. The scope of cavitation phenomena has spread to the food industry. Currently, in the food industry known technology of cavitation treatment of working fluids. Thus, the preparation of a baking and confectionery dough on cavitation-activated water allows to increase the specific volume of bread, increase its elasticity, slow down hardening and reduce the use of baking improvers, and the cavitation treatment of sugar-salt solutions before mixing them with the dough reduces the salt and sugar content in bread 15 ... 20% without changing the taste and nutritional value of the product. The known technology of conditioning the grain before it is milled with cavitation-activated water, the technology of cavitation treatment of brines for meat products, whole milk, and cavitation treatment of water in the water treatment system for food production makes it possible to disinfect it by suppressing and destroying microbial bodies.

Such a widespread use of cavitation for various purposes and technologies is due to the multifunctional spectrum of action of cavitation phenomena.

The cavitation process resembles boiling, but it is not accompanied by a noticeable heating of the liquid. The most surprising thing is that in this case, a liquid, in particular water, for a certain time acquires all the properties inherent in boiling water with a temperature near the boiling point. Such water is a powerful solvent of salts, willingly enters the hydration reaction of food raw material biopolymers - combining them with water molecules, intensively extracts, that is, extracts vitamins and other useful substances from it and does not violate its natural structure, as it has a normal temperature.

When developing designs of cavitation type mixers for this purpose, the problem of ensuring the reliability of these devices, as well as the problem of minimizing pressure losses on the mixer itself, arises.

A known mixer containing a cylindrical housing with an axial channel and swirlers (cavitators) placed sequentially coaxially in the cavity of the housing (RU 2081689, B01F 5/00, application. 05/18/1994, publ. 06/20/1997). The conical sections of the confusers and diffusers together with the swirlers provide the occurrence of cavitation zones. Swirlers can be conical, as well as in the form of a prism, pyramid, hemisphere, etc. The creation of cavitation zones in the stream increases the efficiency of the mixer when processing mixtures of various compositions. However, the complexity of the design of the installation limits the possibility of its use in food production technologies and reduces the reliability.

Known cavitation mixer containing a flow chamber with nozzles for supplying and discharging the processed product and a cavitator made in the form of a disk mounted perpendicular to the axis of the flow chamber with through holes in the form of diffusers (SU 1793954 A3, B01F 5/00, publ. 05.07.90, publ. 02/07/93). To intensify mixing, all diffusers have the same diameter of the inlet, and the diameters of the outlet are determined from a given ratio. The accuracy of the installation of diffusers and the diameter of the holes complicates the design, which reduces the reliability of the mixer.

Known mixer cavitation type to obtain emulsions by cavitation processing the flow of a liquid mixture, used in various industries, including in the food industry. The mixer contains a working chamber of constant cross-section, inlet and outlet pipes located coaxially to the working chamber in the direction of flow and made in the form of a confuser and diffuser, respectively, mixing elements made in the form of a multi-jet nozzle installed at the inlet of the working chamber, and a supply pipe for an additional component ( RU 2158627, B01F 5/08, claimed 23.03.1999, publ. 23.03.1999). A multi-jet nozzle provides a fragmentation of the flow into several high-speed jets and the formation of foci of cavitation at the nozzle hole section. In this case, the pressure in the boundary layers of the jets immediately after the nozzle openings decreases to the saturated vapor pressure, which leads, on the one hand, to the suction of the additional component through the nozzle of the supply of the additional component, and, on the other hand, to intensive vapor release and formation at some distance from the nozzle holes the flow of a high-speed vapor-gas mixture, which, having an average speed higher than the speed of sound, goes into a subsonic flow in a mixing jump with the simultaneous dispersion of additional component in the carrier medium and, as a consequence, the formation of a highly dispersed emulsion. In this case, the presence of a multi-jet nozzle outside the cavitation zone increases the reliability of the device, and a single acceleration of the flow and its subsequent braking in the working chamber reduces energy loss.

The disadvantage of this mixer is the increased energy loss on a multi-jet nozzle. Since for the formation of a supersonic flow in the mixer, the pressure behind the multi-jet nozzle must be less than or equal to the saturated vapor pressure, this means large pressure drops across the nozzle itself. This, in turn, determines the high rates of outflow from a multi-jet nozzle, determined by the physics of supersonic flows. The presence of several nozzle openings leads to increased energy losses. To avoid this, it is necessary to use an “ideally” profiled single-jet nozzle, for example, along the Vitashinsky curve, with a minimum resistance coefficient.

The technical task of the proposed utility model is to increase the reliability of its operation while simplifying the design of the mixer and ensuring the stability of the cavitation process.

This problem is solved by the fact that in the cavitation type mixer for liquid food media containing a working chamber, a mixing nozzle element mounted on the inlet of the chamber, a discharge pipe in the form of a diffuser, located at the camera outlet coaxially with it and the mixing element, and a pipe for supplying an additional mixture component , according to the proposal, the mixing element is made in the form of a single-jet nozzle, inside of which a streamlined flat insert is installed along the axis along its entire length, the thickness of which k at the nozzle exit is 0.1 D, where D is the outlet diameter of the nozzle, and the pointed end of which is located at the entrance to the mixer.

The stability of the cavitation process occurring in the mixer for the formation of a highly dispersed emulsion affects the increase in reliability. The stability of the cavitation process occurs due to vortex formation in the mixing element and additional vortex formation and is ensured by the fact that the mixing element is made in the form of a single-jet nozzle, in the center and axis of which a streamlined flat insert is installed along the entire length, the thickness of which h at the nozzle exit is 0.1D where D is the outlet diameter of the nozzle, and the pointed end of which is located at the inlet to the mixer. Moreover, the simplification of the design of the device is ensured by the fact that the execution of the mixing element in the form of a single-jet nozzle, rather than a multi-jet one, as in the prototype, increases the rigidity of the structure, increasing the reliability of operation. The proposed design minimizes pressure loss on the mixer, which reduces energy consumption during operation of the device and also increases the reliability of its operation.

The technical result is the stability of the cavitation process, which is achieved by vortexing at the nozzle exit, which is further enhanced by the streamlined flat insert installed in it, the dimensions of which are calculated by calculation with respect to the nozzle output diameter.

The initial data for the calculation of hydrodynamic cavitation installations are: nominal and actual fluid flow Q; nominal and actual pressure compliance before installation P ₁ ; allowable pressure drop on the device ΔP; nominal and actual liquid temperature t; physical properties of the medium. The calculation task is to ensure the geometry of the flow part of the hydrodynamic cavitation devices (mixers), corresponding to the formation of supersonic flow cavitants at the initial section of the working chamber, which passes into the subsonic in the mixing jump at the end of the working chamber. Factors such as high rates of outflow from the nozzle, the need to minimize pressure losses in the device, necessitate the following conditions to be fulfilled: the mixing element in the form of a single-jet nozzle, profiled, for example, along the Vitashinsky curve, and having a streamlined insert to create more favorable vortex formation conditions the nozzle exit and, as a consequence, an additional pressure drop at the nozzle exit.

The essence of the proposed utility model is illustrated by drawings, where in FIG. 1 is a general view of the mixer; FIG. 2 - location of the streamlined insert in the mixing element (single-jet nozzle), in FIG. 3 is a view A of FIG. 2.

The cavitation type mixer (Fig. 1) contains a cylindrical working chamber 1, a mixing nozzle element 2, mounted at the inlet of the chamber, a branch pipe 3, coaxially located at the outlet of the working chamber along the flow direction and made in the form of a diffuser, a pipe 4 for supplying an additional mixture component mounted directly behind the nozzle element 2 at the inlet of the working chamber 1.

On the inner surface of the working chamber at the beginning of its end section, equal to 2 ... 3 diameters from the outlet normal section of the chamber, a threshold-like protrusion 5 is made, and radial longitudinal ribs 6 are located along the entire length of its end section.

A streamlined flat insert 7 is installed in the center of the single-jet nozzle 2 along its entire length, the thickness of which is b at the nozzle exit 0.1D, where D is the outlet diameter of the nozzle, and which has a pointed end 8 opposite the flow.

The device operates as follows.

One of the components of the mixture or a multicomponent food mixture (dispersion medium plus dispersed phase) is fed into the mixing element 2 with insert 7 (single-jet nozzle or cavitation stimulator), in which the flow is accelerated and the pressure at the nozzle exit to a pressure drop to saturated vapor pressure. This leads to suction of the additional medium from the nozzle 4 for supplying the additional component located directly behind the single-jet nozzle, intense steam generation and the formation at some distance from the nozzle of the supersonic vapor-gas-liquid flow, which goes into the subsonic flow in the mixing jump. In the mixing jump, the additional component (dispersed phase) is intensively crushed to microparticles and penetrated into the carrier dispersion medium and, as a result, the formation of a highly dispersed emulsion.

The location of the streamlined insert 7 inside the nozzle 2 changes the geometry of the flow part, creating more favorable conditions for vortex formation at the nozzle exit and, as a result, an additional pressure drop at the nozzle exit up to the saturated vapor pressure. This ensures the sustainable development of cavitation phenomena, thereby increasing the intensity of steam generation and the formation of a supersonic vapor-gas-liquid flow, which ultimately increases the reliability of the cavitation mixer and the quality of the emulsified mixture.

In addition, simplifying the design of the mixing element facilitates the processing of the mixer with detergents after the end of work.

The proposed mixer cavitation type can be used in technological lines of food production, providing reliable non-stop operation of technological lines for the processing of liquid food media, improving and maintaining the quality of processed products.

For example, the use of the proposed mixer in meat processing plants during its continuous operation ensures the exclusion from the brine for product preparation, and, therefore, from the final product, inorganic moisture-retaining and color-stabilizing additives, reducing the content of flavoring and preserving additives, as well as reducing the time of the salting process while maintaining the traditional taste and the appearance of the finished product. The use of technological equipment with a cavitation type mixer has a positive effect on the quality of manufactured products, as it significantly improves its properties and extends the sales time by 2 times.

Claims (1)

Cavitation type mixer for liquid food media, comprising a working chamber, a mixing nozzle element fixed to the inlet of the chamber, a discharge pipe in the form of a diffuser located at the outlet of the chamber coaxially with the mixing element, and a supply pipe for the additive component of the mixture, characterized in that the mixing element made in the form of a single-jet nozzle, inside of which, along the axis along its entire length, a streamlined flat insert is installed, the thickness of which h at the nozzle exit is 0.1D, where D is the outlet diameter of the nozzle and the pointed the end of which is located at the entrance to the mixer.

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