SU1669519A1 - A method for preparing emulsion and device therefor - Google Patents

Abstract

The invention relates to the food industry, agriculture and is used to prepare liquid substitutes for whole milk, in addition, it can be used in the fuel and energy and engineering industries. The aim of the invention is to improve the quality of emulsification, reduce energy consumption and simplify the process. The two-stage dispersion processes are carried out in a steam jet apparatus. In the first stage of dispersion, the emulsifiable components are introduced into steam at a speed of 500-800 m / s, and in the second stage, the speed is maintained in the supersonic flow regime for a given medium. The device comprises a housing 9, inside of which there is a mixing chamber 13 with confused 14, a cylindrical 15 and a diffuser 16 parts, and in the chamber 13 there is a pipe 12 for feeding the components. The device also has a nozzle 1 and an additional chamber 2 with a nozzle 4 for supplying emulsifiable components. Additional chamber 2 is placed coaxially to the nozzle with the formation of an annular gap and an annular gap at the nozzle exit. The mixing chamber 13 and the nozzle 1 are mounted with the possibility of axial movement. 2 sp.f-ly, 1 ill.

Description

The invention relates to the food industry, agriculture, and is used to prepare liquid substitutes for whole milk, in addition, it can be used in the fuel and energy and engineering industries, in particular for the preparation of stable, water-fuel and water-oil emulsions.

The purpose of the invention is to improve the quality of emulsification, reduce energy consumption and simplify the process.

In the method of preparing liquid emulsions, the components of the emulsion are mixed and subjected to two-stage jet dispersion, mixing and dispersing are performed using steam as the working medium of jet devices, which simultaneously provides high-quality emulsification and mixing, heating the emulsion due to condensation of steam in it and transportation emulsion due to steam energy.

The method significantly simplifies the process of preparing emulsions, so

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as in this case, special devices (heaters, electropumps) are not required for emulsion preparation. In this case, the energy consumption is significantly reduced, since the emulsion is circulated in the proposed method as the corresponding effect of using steam to disperse the components.

Improving the quality of the emulsion is provided by the following physical processes. The pairs entering the nozzle, due to the nozzle geometry, expand, accelerating to supersonic velocities (500-800 m / s) at the nozzle exit. The emulsifiable components of the emulsion, which are relatively immobile, are practically stationary and therefore in contact with steam, they are intensively crushed (dispersing) into small droplets. This formed droplets of the emulsifiable components are transported by supersonic flow. steam flow, experience significant hydrodynamic effects from it and therefore are crushed (dispersed) into smaller ones. Then skimmed milk is introduced into the flow when the droplets of emulsifiable components that have received a significant velocity in the vapor flow collide with this introduced almost stationary liquid medium, as well as with fixed walls of the channel for supplying this medium, additional emulsification occurs. As a result of crushing small droplets injected into the vapor flow of liquid media, a fine peri-liquid liquid flow is formed. It is known that for such a flow structure the sound propagation velocity in it is much less than this characteristic for a single-phase flow (only steam or only liquid) and is 10-50 m / s. Since the speeds of movement of a two-phase flow are much higher than the indicated values, the flow, becoming two-phase in its physical state, is even more removed to the supersonic region. With further flow in the jet apparatus of this supersonic two-phase flow, having a static pressure less than atmospheric, a pressure jump occurs that compensates for this difference and ensures the outflow from the apparatus into the atmosphere or into the system with even greater pressure. A sharp hydrodynamic impact causes further crushing (dispersion) of the emulsifiable components. The intensity of this blow is greater, the more the speed of the two-phase flow exceeded the speed

spread sound in it. The magnitude of the velocity of the two-phase flow before the pressure jump and, therefore, the intensity of the shock is provided by geometrical

the size of the flow channel of this stream,

The drawing shows schematically the device, a general view.

The device comprises a nozzle 1, placed inside an additional chamber 2, connected through valve 3 with a pipeline 4 to supply emulsifiable components. An additional camera is placed coaxially to the nozzle 1 with the formation of an annular gap, and between

5, the outlet edge of the nozzle 1 and the inner wall of the additional chamber 2 are provided with an annular slot 5. The nozzle entrance 1 is connected through a control valve 6 to the steam supply line 7. With

0 a cap nut 8, a nozzle 1, an additional chamber 2 and a pipeline 7 are attached to the housing 9. The internal cavity 10 of the housing 9 is connected to the supply pipe of the remaining components of the emulsion through the valve 11 and the branch pipe 12. Coaxially with the nozzle 1 in the housing 9 is mounted with the possibility of axial movement of the mixing chamber 13, containing confusable part 14, cylindrical part 15 and diffuser part 16.

0 A gap 17 is made between the surface of the confuser 14 and the end surface of the additional chamber 2. To the output of the emulsifier, the output pipe 19 is connected to the outlet of the emulsifier 18 with regulating

5 fittings 20. Between the nozzle 1 and the additional chamber 2, one of the interchangeable washers 21 is installed to adjust the size of the annular gap 5. The housing 9 has a threaded hole in which a screw 22 is installed to fix the mixing chamber.

A pressure gauge 23 is installed on the steam pipe 7 after the regulating valve 6. To control the pressure in the confuser 14 and in the pipe 5, the vacuum pressure gauge 24 and the pressure gauge 25 are installed, respectively.

The device works as follows.

Steam through control valves 6

0, the pipeline 7 is supplied to the nozzle 1, where, due to the geometry of the nozzle, its supersonic flow is ensured for 500-800 m / s. As a result, a vacuum is created at the exit edge of the nozzle 1, allowing injection of emulsifiable components supplied through valve 3 through conduit 4 to the inside of additional chamber 2. As a result of injection of emulsifiable components through slot 5 into the jet of high-speed steam, the first phase dispersion. In this case, the dispersion effect is achieved not only due to the injection of emulsifiable components into the vacuum space, but also due to a sharp acceleration and their splitting into droplets when the high-speed vapor flow disrupts from the gap 5. The size of the slit 5, and, consequently, the flow rate of emulsifiable components, is controlled by axial movement of the nozzle 1 relative to the additional chamber 2 by changing the thickness of the interchangeable washers 21. Through the nozzle 12 through the valve 11 into the cavity 10 of the housing 9, the other components of the emulsion are fed through injected into the steam jet. The flow rate of the remaining components of the emulsion is controlled by changing the size of the slit 17 by axial displacement of the mixing chamber 13 relative to the housing 9, followed by fixing with a screw 22. The speed of movement of steam with particles of emulsifiable components is many times greater than the flow rate of the remaining components of the emulsion and when they collide the second phase of dispersion occurs. In the confuser 14, the steam entrains and accelerates the flow of the remaining components of the emulsion, where they mix and in the resulting two-phase flow there is an exchange of energy pulses between the vapor and the liquid and partial vapor condensation, which also contributes to dispersion. This provides highly efficient heat exchange.

In the confuser 14 and at the entrance to the cylindrical part 15, the flow structure is rearranged: the medium becomes bubbly or frothy. The speed of propagation of small disturbances (the speed of the sound wave) sharply decreases to 10–50 m / s and, despite moderate absolute flow velocities (more than 0–50 m / s), the two-phase gas-liquid flow is transported in a supersonic mode. At the exit from the cylindrical part 15 (at the entrance to the diffuser part 16) a compression shock occurs — condensation, in which the vapor phase condensation ends. As a result of the avalanche-like collapse of vapor bubbles in the shock, there is a sharp increase in pressure. The jump translates the supersonic flow in a subsonic one and at the same time in the zone of pressure increase, a transition takes place from the two-phase gas-liquid flow structure to the single-phase liquid structure. During condensation of steam, and especially in a pressure surge during the collapse of steam bubbles, a fourth stage of dispersion occurs.

As is well known, mechanical disturbances propagate in the stream at the speed of sound characteristic of a given medium. A change in pressure in the entrance pipeline 19. through which a single-phase liquid flow flows, leads to the formation of a disturbance wave propagating at a speed of sound in a given liquid medium. This wave propagates in all directions, including the direction upstream, however, in this direction it propagates only up to a pressure jump (condensation compaction), where it is swept down by supersonic flow that takes place before the shock. Thus, mechanical perturbations from the pipeline 19 cannot penetrate into the additional zone - into the cavity 10.

The flow rate of the vapor and emulsion components is determined by the formula

Q f

v / SP P

0)

where p is the density of the dosed medium;

D P - pressure drop across the restriction device.

DR Ro - Pi

(2)

where Ro is the pressure to the corresponding device (nozzle 1, scholi 5 and 17),

P is the pressure behind the corresponding restriction device (nozzle 1, slots 5 and 17).

From formulas (1) and (2), it follows that in order to ensure the consistency of the dispensed steam and emulsion components, it is necessary to stabilize the parameters / e, PO, PL. The parameters p and PO for each of the dispensed media are stabilized by known means by adjusting the temperature and pressure to the appropriate value. narrowing device. From this, it follows that the pressure fluctuations in the outlet pipe 19 do not affect the value of the parameter PL and, consequently, the constancy of the flow rate of the dosing media.

Along with ensuring mixing in the stream, dispensing the components and obtaining a fine emulsion, it is heated in the stream of this emulsion due to condensation of steam in it. Since steam consumption is stabilized, the heating value at a constant input parameters will also be constant. In addition, the transportation of both the components of the emulsion and the emulsion itself is carried out at the expense of steam energy without additional devices.

Example. Bone fat, vitamins AI and Oz on a fat basis, phosphatide concentrate are mixed in a ratio of 20: 0.006: 3.7 respectively, heated to melt the fat to a temperature of 55-60 ° C and the formed mixture is fed through atmospheric pressure through valve 3 to additional chamber 2 as emulsifiable components Skimmed milk (reverse) at a temperature of 20-35 ° C through the pipe 12 through the valve 11 is fed under atmospheric pressure into the cavity 10. The pipeline 7 through the regulating valve 6 serves steam into the steam nozzle 1. The vapor pressure at the inlet to the nozzle 1 creates within (0.5-2) kgf / cm with the help of regulating valves 6. The value of the specified pressure is adjusted according to the indications of the pressure gauge 23. The steam at the exit of the nozzle 1 expires at a supersonic speed of 500-800 m / s.

As a result, a vacuum is created at the exit edge of the nozzle 1 and in the confuser 14, which provides injection; initially fatty emulsifiable components of ZHZM, and then skimmed in a ratio of 2: 100. In the nozzle 1, in the confuser 14 and the cylindrical part 15, the described processes take place, leading to the formation of a GEMF device at the outlet with a 2% fat content. The proposed method is carried out in the production of GEMF with a capacity of 3-5 tons / h. The life cycle is heated up to 15-25 ° C compared to the skip temperature. Transportation of the life cycle equipment is carried out without additional pumps at the expense of steam energy. Adjusting the fat content of the GCM is carried out by changing the size of the annular gap 5. This is carried out by axial movement and fixing the nozzle 1 relative to the additional chamber 2 by installing interchangeable washers 21 of various thickness. The flow control of the skim is carried out by changing the size of the annular slot 17 by axial movement of the chamber 13 relative to the housing 9, followed by fixation by the screw 22.

The verification of the presence of a pressure jump, and, consequently, of a supersonic flow of a two-phase gas-liquid flow, is carried out as follows. With the help of the reinforcement 20, it is changed in the outlet pipe 19 according to the indications of the pressure gauge 25 in the range from 0 to 1.5 kgf / cm2 at the vapor pressure in front of the nozzle 1 about 2 kgf / cm2. In this case, the reading of the pressure gauge 24 remains unchanged. The costs of the life-cycle components of the life-cycle center and, consequently, its fat content also remain unchanged. This indicates that the disturbances in the outlet pipe 19 do not pass in the confuser, i.e. there is a supersonic two-phase gas-liquid flow and a pressure jump is created which does not allow disturbances from the upstream zone to the upstream one. Obtained during the implementation of the method with the help of the device, the emulsion (ЖЗЦМ) is resistant to delamination, it lasts more than 48 hours at 50 ° C without delamination.

Thus, the method and device for its implementation allows to simplify, reduce energy consumption and expand functionality, as well as reduce the metal consumption of the device, since in the proposed method and device the dosing of emulsion components, their transportation, mixing, emulsification, transportation of the emulsion and its heating simultaneously and in the same device, in contrast to the known, where these operations are performed separately and sequentially on the equipment for carrying out each of the operations separately.

Claims (2)

1. An emulsion preparation method that involves a two-stage dispersion in an inkjet apparatus with dispersion in the first stage of emulsifiable components and, accordingly, a mixture of the resulting emulsion with the other components in the second stage, which is so that, in order to improve the quality of emulsification, reduce energy consumption and simplify the process, emulsification is carried out in a steam jet apparatus at a vapor velocity of 500-800 m / s, and during dispersion in the second stage, the velocity is maintained in a supersonic mode nor for the medium, 2. An emulsion preparation device, comprising a housing inside which a mixing chamber with confused cylindrical and diffuser parts is installed, a nozzle mounted coaxially with the displacement chamber, and a component supply system, which, in order to improve the quality of emulsification , reducing energy consumption, it is equipped with an additional chamber placed coaxially to the nozzle with the formation of an annular gap, the component supply system consists of a pipeline to supply emulsifiable components and a supply pipe for the rest to components, while the pipeline supplying emulsified components is connected to an additional chamber, the supply pipe of the remaining components is mounted on the body, and the nozzle and the mixing chamber are mounted with the possibility of axial movement, This nozzle is connected through a regulating apparatus with a steam line.