Homogenizer for what it is needed. The principle of the homogenizer of high pressure. I. Determination of creation setting speed

Homogenizer

Designed for crushing and uniform distribution of fat balls in milk and liquid dairy products. Homogenizers are high-pressure multiporter pumps with a homogenizing head. Homogenizers consist of the following main nodes: a crank-connecting mechanism with a system of lubrication and cooling, a plunger block with a homogenizing (one or two steps) and pressure gauge heads and a safety valve, stripes with a drive. The drive is carried out from the electric motor using the clinorem transmission. Homogenization is carried out by passing the product under high pressure, at high speed through the homogenizing head, which represents two (one) of the slot between the fit valve and the saddle, interconnected by the channel. The pressure in the homogenizer is regulated by rotating screws (from 0 to 200 atm), changing the slot size between the valve and the saddle.

In homogenizers, a coercive system of lubrication of the most loaded, driving steam combined with spraying oil inside the case is used. All parts in contact with the product are made of food stainless steel.

Figure 8 - Homogenizer A1 -

Homogenizer for two-stage homogenization: 1 - coil cooler; 2 - Pipeline for feeding chalk; 3 - crank-connecting mechanism; 4 - homogenizing valve; 5 - block of cylinders; 6 - coupling; 7 - Stanina; 8 - device for extension of the electric motor

Packaging milk

Figure 9 - Milk Packaging Scheme in Polyethylene Packages

Machine for packing milk in packages (bags): 1 roll; 2-mechanism for applying the date; 3-bactericidal lamp; -Forming pipe; 5-disamer; 6 - mechanism of longitudinal welding; 7-mechanism of transverse welding and cutting packets; 8 - foot and sliced \u200b\u200bpackage; 9-conveyor pacts; 10- bunker; 11-photocell counting device. The packaging paper tape is first fed from roll 1 to the chemical processing capacity, which is filled with hydrogen peroxide, and then envelopes the guide roller and passes in the zone of the bactericidal lamp 3. In the molding wheel, the tape is coagulated into the pipe 4. The paper pipe passes through the electric heater, which heats up quickly Up to 300-400 ° C, as a result of which hydrogen peroxide instantly decomposes, and thereby reliable sterilization of packages is achieved. After sterilizing the packets in the paper pipe, a continuous stream comes sterilized and chilled milk. At the same time, pricing is completely excluded. At the bottom of the conveyor, there is a mechanism 7 for a magnificent cutting of packages filled with milk. Sliced \u200b\u200bpackages are served in the buckets of the lifting mechanism of the stacker, which is reinforced at the base of the machine. Packages are automatically stacked in special hexagon baskets.

2. Review of literary sources

Currently, there are a wide variety of machines for homogenization of dairy products of Russian and foreign production. These include homogenizers, with a single and two-stage homogenizing head, as well as valve and plunger, high and low homogenization pressure. Consider some options for homogenization equipment.

Homogenizers are designed for crushing and uniform distribution of fat balls in milk and liquid dairy products. Homogenizers are high-pressure multiporter pumps with a homogenizing head. Their drive is carried out from electric motors using a clinorem.

Homogenization is carried out by passing the product under high pressure at high speed through the homogenizing head, which represents two steps - the slots between the proprietary valve and the saddle, interconnected by the channel. The pressure in the homogenizer is regulated by the rotation of the screws that change the slot size between the valve and the saddle. At the same time, at the first stage, the homogenization of homogenization required for a particular product is installed, on the second - working pressure.

Homogenizers consist of the following main nodes: a crank-connecting mechanism with a system of lubricant and cooling, a plunger block with a homogenizing and pressure gauge head and a safety valve, strivine with a drive. The drive of the homogenizer is carried out from the electric motor using the clinorem. The crank-rocker mechanism of the homogenizer is designed to convert the rotational motion transmitted by the clinoremable transmission from the electric motor, into the reciprocating movement of plungers, which, by means of clarity seals, are included in the operating chambers of the plunger block and, making suction and injection moves, create the necessary pressure of the homogenizing fluid in it.

The crank-connecting mechanism consists of a housing; crankshaft mounted on two conical roller bearings; Bearing covers; rods with lids and liners; crawls, hinged-connected with rods using fingers; glasses; seals; Cover cover and slave pulley, console attached at the end of the crankshaft. The inner cavity of the crank crank mechanism is an oil bath. In the posterior wall of the case mounted asset and drain plug.

2.1 Homogenizer OGB-M

Figure 10 - Homogenizer OGB - M

a - general view: 1 - bed; 2 - electric motor; 3 - wedge belts; 4 - tension screw; 5 - pulley; 6 - crankshaft; 7 - homogenizing head; 12 - washing device; B - section of the cylinder block and a homogenizing head: 1 - suction channel; 2 - suction valve; 4 - discharge channel; 5 - pressure gauge; 6 - screw; 7 - spring; 8 - rod; 9 - valve; 10 - saddle.

2.2 Homogenizer A1-OGM-2.5

Figure 11 - Homogenizer A1-OGM-2.5

1 - bed; 2 - Safety valve; 3 - pressure gauge; 4 - plunger block; 5 - grease pressure grease; In ammeter; 7 - Homogenizing head.

Technical characteristics of the Homogenizer A1-OGM-2.5

Performance, l / h 1250

Maximum hydrogenization pressure, MPa 18

Number of homogenization steps, pieces 2

Number of plungers, pc 3

Installed engine power, kW 12

Overall dimensions, mm 970 × 860 × 1400

Homogenizers of the A1-OGM-2.5 brand have a forced system for lubricating the most loaded rubbing pairs, which is used in combination with spraying oil inside the case, which increases the heat transfer. The cooling of the oil in these homogenizers is made by tap water by means of a coil, a cooling device, laid on the bottom of the housing, and plungers are cooled with tap water falling on them through holes in the pipe. The cooling system has a duct relay designed to control the flow of water. The compulsory lubrication system includes a mesh filter, an individual drive oil pump, a junction box, a safety valve and a pressure gauge for pressure control in the oil system. A plunger block is fastened to the crank mechanism of the crank mechanism with two studs, which is designed to suck the product from the supply line and the discharge of it under high pressure in the homogenizing head. The plunger block includes a block, plungers, lid seals, bottom, upper and front covers, nuts, suction and injection valves, valve seats, gaskets, sleeves, springs, flange, fitting and filter, which is installed in the absorbing canapes of the unit, to the end The plane of the plunger block is attached to the homogenizing head, designed to perform a two-stage homogenization of the product due to the passage of high pressure through the slot between the valve and the valve seat in each stage. The homogenizing head is two single-stage heads of a similar design, connected together and the connected channel, allowing the product to switch consistently from the first stage to the second. Each of the two-stage homogenizing head steps consists of a housing, valve, valve seat and a pressure device, including a glass, rod, spring and pressure screw with a handle.

Homogenization pressure adjustment is performed by rotating screws. When setting the homogenization mode of the product at the first stage, 3/4 of the required pressure of homogenization is set, and then at the second stage, the pressure rotation rotation increases pressure to the worker. On the upper plane of the plunger block, a pressure gauge is fastened, which is designed to monitor the pressure of homogenization, i.e. Pressure on the discharge collector of the plunger block. The pressure gauge head has a throttling device, which makes it possible to effectively reduce the amplitude of the pressure gauge oscillation. The pressure gauge head consists of a housing, needles, seals, nuts, pressing seal, washers and a membrane separator pressure gauge. To the end plane of the plunger block from the side opposite to fasten the homogenizing head, a safety valve is attached, which prevents the hydrogenization pressure above the nominal. The safety valve consists of a screw, lock nut, height, springs, valves and valve seat. On the maximum homogenization pressure, the safety valve is configured by the rotation of the pressure screw, which transmits the force of pressing the valve through the spring. The bed is a welded construction of challers, sheltered sheet steel. On the upper plane of the bed, a crank-connecting mechanism is established. Inside the bed on two brackets, the slab is hinged, which is installed by the electric motor. On the other hand, the stove is supported by screws that adjust the tension of wedge belts. The window of the Homogenizers of the A1-OGM-2.5 grade is installed on four adjustable by the supports. The side windows of the beds are closed with removable lids. The upper part of the bed is closed by a casing designed to protect the mechanisms from damage and giving the homogenizer the necessary aesthetic form. Milk or milk product Served using a pump to the suction channel of the plunger block. From the working cavity of the block, the product under pressure is supplied through the injection channel into the homogenizing head and with high speed passes through the ring gap, which is formed between the proprietary surfaces of the homogenizing valve and its seat. In this case, dispersion of the fat phase of the product occurs.

In the future, the homogenizing head product is sent by pipeline to further processing or storage.

2.3 GM-0.5 / 20 homogenizer

Figure 12 - Homogenizer GM-0.5 / 20

Technical specifications

Performance, l / hour 500

Power, kW 4

Number of homogenization steps, pcs 2

Homogenization pressure, MPa 20

2.4 Vacuum Mixer Homogenizer

Figure13 - Vacuum Mixer-Homogenizer

Installation is a vacuum reactor, with a mixing device to which a homogenizer is connected to recycling. After loading the main components into the reactor capacity, air is pumped out of the system, and the installation is included in the recirculation mode, during which grinding and mixing loaded components occurs. The built-in funnel allows you to access the necessary components in the homogenization process.

The main advantage of this design is that it allows you to mix with each other such components that are solidified during mixing in the open air during the mixing process.

2.5 Homogenizer SBE - 3

Figure 14-Homogenizer SW - 3

The Homogenizer of the SBE - 3 model is used to obtain a finely dispersed, equalnered, stable structure of viscous products obtained from several ingredients. The product, falling into a homogenizer, passes through narrow, constantly changing gaps between the rotor and the stator. As a result, the product is grinding to a fine state and its simultaneous transfer. The homogenizer is used in the food, cosmetic, chemical, pharmaceutical industries.

Specifications Homogenizer SPA - 3

2.6 Homogenizers manufactured by Bertoli SRL H5150

Figure 15 - Homogenizers manufactured by BERTOLI SRL

Technical characteristics H5150.

Performance l / hour 22000

Number of plungers, pcs. five

Energy consumption, kW 160

Overall dimensions, mm 1440x1680x2660

Technical advantages

1. High efficiency of milk homogenization. With a pressure of 200 bar and a temperature of 65 ... 70s, the effectiveness of homogenization is 90 ... 95%, which is 10 ... 15% better than domestic analogs. The average size of fat balls after homogenization is 0.85 μm.

2. Lack of vibrations and noise. Supports of the homogenizer are attached to the bed through vibrarous compounds, which in practice eliminates vibration when working. The test level of vibrations in the range of 0.45 ... 3.0 mm / s (for different measurement points), meets the requirements of the EU.

3. Wearness of the valve group. The homogenizing head is made of nickel-chromium-molybdenum alloy specifically for high pressures. Self-centered stainless pistons. Valves and saddles are made of high-quality wear-resistant stainless alloy.

4. Fixed and adjustable performance. A homogenizer can be equipped with a fixed-performance control cabinet or control cabinet for adjustable performance.

3. Design development

Currently, there are a wide variety of machines for homogenization of dairy products of Russian and foreign production. These include homogenizers, with a single and two-stage homogenizing head, as well as valve and plunger, high and low homogenization pressure.

Homogenization is carried out by passing the product under high pressure at high speed through the homogenizing head, which represents two steps - the slots between the proprietary valve and the saddle, interconnected by the channel. The pressure in the homogenizer is regulated by the rotation of the screws that change the slot size between the valve and the saddle. At the same time, at the first stage, the homogenization of homogenization required for a particular product is installed, on the second - working pressure. In this course, the project is considered to modernize the homogenizing head, to increase the performance of which the vortex effect is used. Consider the design of the modernized homogenizing head.

3.1 Homogenizing head

containing a saddle and a valve with a slit located between them, formed by concentric ring rollers of the saddle and valve, with a discharge chamber located in the slot, the grooves for the supply of the product to the slit located at the top of the head, damping cavity, built into the saddle or valve, which differs in that the saddle and the valve are made with the possibility of rotation in opposite sides under the action of a moving milk flow and installed in the bearings located in a fixed body containing a fitting for the output of a homogenized product, while the groove for the supply of the product to the labyrinth slit is made in the form of a confusion obtained by The reservoir of the valve seat with the formation of conical surfaces, and the vertices of their cones are directed in opposite sides, and along the entire length of the conical surfaces of the seat and valve at an angle to the generators, round grooves are made, directed in different directions at the saddle and valve.

The homogenizing head works as follows:

The flow of the product, such as milk, is supplied to the groove and, moving to the labyrinth slit 3, makes rotating in different directions of the saddle and the valve at the expense of round grooves located on their conical surfaces. This contributes to avoiding the tightness of the slit, makes it possible to easily adjust the size of the slot in the homogenization process. When leaked at high speed, the product stream is homogenized, i.e. There is a grinding of coarse suspension and large particles of the product, such as fat balls. The efficiency of the homogenization of the product contributes not only to the presence of the slit of the envelopes and turns, but also the rotation of the saddle and the valve in the opposite sides. A homogenized product is excreted through the nozzle.

The proposed homogenized head allows you to improve the quality of homogenization due to the additional turbulization of the flow due to the rotation of the saddle and the valve in the opposite sides. As a result, the bug oblilation is significantly reduced, which positively affects the quality of homogenization and, as a result, the performance of the homogenization process increases.

3.2 Engineering calculations

The performance of the homogenizer is equal to the supply of its pump. For plunger pumps, the feed depends on the diameter of the plungers and the progress, the number of plungers and the number of crankshaft revolutions. With specified parameters of the machine, the performance of the V second can be calculated by the formula

V sec \u003d m 3 / s, (2.6)

where D is the diameter of the plunger, m;

S - Plunger's move, m;

p - angular speed of rotation of the crankshaft, r / s;

φ is the volumetric to. p. d. pump (for milk \u003d 0.85; for a viscous product is significantly less);

z - Number of plungers.

The power N necessary for the operation of the homogenizer is determined by the formula for calculating the power of pumps

where p 0 is a pressure developed by the plunges of the homogenizer (pressure in front of the valve), N / m 2;

η is a mechanical to. p. d. homogenizer (\u003d 0.75).

As a result of the costs of a large number of mechanical energy, which turns into heat, with the valve homogenization, the product is noticeably heated.

Increasing the temperature of the product in the homogenizer can be calculated by the formula:

Δt \u003d hail, (2.8)

where n is the required power, W;

V sec - the volumetric capacity of the homogenizer, M 3 / CE;

ρ is the density of the product, kg / m 3;

C-mass heat capacity of the product, J / (kg ∙ hail).

Calculation and selection of the structural parameters of the homogenizing head.

The effectiveness of homogenization depends on the hydraulic conditions in the zone of the valve gap. These conditions are mainly determined by the pressure of homogenization, on which the speed of fluid movement in the slot and the height of the valve slot depends. In the radially divergent valve slit, the flow rate V 1 has the greatest value At the beginning of the slot on the R radius. As the stream expands to the output, the speed is reduced to the value of V 2. The largest theoretical velocity V 1 depends on the pressure of homogenization and can be calculated according to Torricelli formula:

where - hydrogenization pressure, PA;

All prices are subject to a homogenizer control cabinet.

Terms of payment:

50% advance after signing the supply contract,

50% surcharge on the readiness of equipment to shipment.

Production time - 45 working days.

Warranty - 12 months.

The milk homogenizer is an installation that allows you to crush fat balls of milk, dairy products and mixtures intended for the production of ice cream. They are used in a variety of dairy production lines. It is also possible to homogenize dairy mixes using other installations (emulsifiers, emulsors, vibrators, etc.), but they are not so effective.

In our time, most often producers of dairy products are used by a homogenizer for a valve type milk, which is a high-pressure multi-gas pump equipped with homogenizing heads. The composition of homogenizers includes: crank-connecting devices with lubrication and cooling systems; Plunger devices having a homogenizing head and several manometrics; Safety valves; Stanna. The installation from the electric motor with the help of clinorem gears.

The work of the crank-connecting mechanism allows you to transform rotational movements from the clinoremable transmission and an electric motor into the reciprocating movements of the plunger. Plungers, thanks to centered seals, enter the working chamber and make a suction and injection influence, creating, thereby, a certain pressure that allows homogenize the milk mixture. The crystrum-connecting joint mechanism of the homogenizer for milk includes a crankshaft (having two conical roller bearings), the bearing cover, the connecting rod (equipped with lid inserts), the slider (which is connected by joint hinges), glasses, seals, the case cover and the slave pulley (fixed on The end of the crankshaft). The inner cavity of the crank-connecting mechanisms are oil baths equipped with oil supplies and drain plugs. In dairy homogenizers, the lubrication of the rubbing parts of crank-connecting mechanisms occurs due to the spraying of the oil during the rotation of the crankshal. The oil in the inner cavity is cooled by heat exchange with environmental. Water water It goes for cooling plungers.

Some milk homogenizers are equipped with a forced lubrication system of some, more exposed to friction, parts. Cooling units of such homogenizers have a serpentine in which heat-conducting water flows, cooling oil. They are stacked on the bottom of the building. In such installations, it is necessary to preserve a special duct relay that ensures water supply control. The plunger unit of the homogenizer is attached by two studs to the housing of the crank-connecting mechanism. It ensures the absorption of the dairy mixture from the guide of the highway and injected it under pressure to the homogenizing head.

Plunger blocks consist of a housing, plunger centers, covers (lower, upper and front), suction and injection valves, valve saddles, gaskets, sleeves, springs, flange, fitting, filtering device. The end plane of plunger blocks has a homogenizing head designed for the two-stage process of homogenization of the dairy mixture, which occurs due to the passage of the mixture through the hole between the valves and high-pressure valves.

A pressure gauge, providing pressure control in homogenization, is fixed on the upper plane of plunger blocks. Manometer heads include throttling devices that allow you to reduce the oscillations of the arrow. They consist of a hull, needles, seals, pressing nuts, washers and pressure gauges equipped with membrane separators. Safety valves located opposite homogenizing heads, exclude a sharp increase in pressure above the necessary. Safety valves consist of screw, lock nuts, heels, springs, valves and valve seat. Safety valve clamping screws are used to adjust the nominal pressure. The beds of homogenizers for milk are cast or welded structures from channels or from the lured sheet steels. The crank-connecting mechanism is located in the top of the bed, and the plate with the electric motor is attached inside with two brackets with hinged fasteners. This slab is supported screws that regulate wedge belts. The bed is equipped with four height-adjustable supports. Bock beds can be closed with a removable lid.

The milk mixture is sent to the pump into the suction channels of plunger blocks. Next, the products under high pressure through the injection valve are directed to homogenizing heads and at high speed passes through the hole between the surface of the homogenizing valves and their saddles. In the process of such an impact, homogenization of the mixture occurs and it becomes homogeneous. Next, the milk mixture is stored or for recycling.

Did you think about why the taste homemaking, mayonnaise, ketchup, juice, cream or vegetable puree is so different from the shop? Do you think only in dyes, preservatives and other nutritional supplements that make the taste of these products more saturated? You are mistaken, the whole thing in the production technology of these products, which does not do without the use of the homogenizer.

In general, the homogenizer is a mechanical apparatus intended for mixing liquid consistency products. The main feature is that the device does not simply mix products as an ordinary mixer, and does it so carefully that all components included in the liquid base form a single homogeneous mass. This increases the shelf life of food and makes it more delicious.

If you dream about acquiring a laboratory homogenizer, it will be useful for you to read the details on the site http://labfarma.ru about its technical capabilities. At home, such a device will also be useful, and from this article you will learn how the device can be, ideally suitable for this.

Features of work

To begin with, I would like to tell a little about the features of the homogenizer:

1. The device consists of a piston pump in which the source components are served through the fitting.
2. The grinding process occurs by extruding the product through a narrow nozzle, the diameter of which can be controlled manually. At the same time, the degree of crushing of the component of the product is also controlled.
3. In addition to grinding, even uniform mixing occurs, which can occur both in a gas and liquid medium.

In technical conditions, after the grinding stage and stirring in the homogenizer, the product pasteurizes.

How to choose a home appliance

According to the principle of operation, homogenizers are two types: submersible and planetary. When choosing a home appliance, you should know the following:

1. The submersible homogenizer will fit perfectly. Models operating only in pulse mode are the simplest, but they will be enough to grind a small amount of food.
2. It is desirable that the instrument model is supplemented with an anti-precipitating nozzle. The presence of a variator will control the speed of rotation of the nozzle.
3. The model with the rubberized handle is more convenient for use. It is also important that the vent holes are located at the top of the device.

AND special attention Materials should be given. The nozzles are better to choose from a stainless steel, and the body is made of high-quality steel.

Chemical, food, construction and many other industries are unthinkable without the use of a variety of suspensions, emulsions and colloidal solutions that helps cook.

As an example, lubricating machine-building emulsions can be mentioned, fuel emulsions modified by polymers bitumen, as well as a wide range of food fat emulsions, all sorts of gels, creams, pastes - the list is truly infinite. To obtain high-quality homogeneous multicomponent mixtures and colloidal solutions, special mixing lines set in enterprises, which necessarily include dispersion devices - the finest grinding of solid or liquid components.

If the production workers are the task of crushing an exclusively liquid fraction and its uniform distribution in a liquid basis (dispersed medium), or a suspension with a small volume of solid phase is required - a homogenizer is used as a working unit. The resistance of emulsions to the bundle is determined primarily by the size of the dispersed phase. For example, in a stable water-fat emulsion, the size of the fat droplets should not exceed 5 microns. And modern centrifugal (rotary) homogenizers easily provide this condition. Rotary homogenizer It is also used if necessary to reduce the size of the droplets of the finished emulsion to 1-2 microns - the so-called secondary homogenization.

Rotary and valve homogenizer

If recently the most common type of homogenizers were, then at present, preference is given centrifugal (rotary) homogenizersWhat is due to their organic advantages: a small mass, compact dimensions, low power consumption and simple design, and therefore high reliability.

Depending on the model, the speed of rotation of the rotor of the homogenizer varies from 2000 to 18000 rpm. The intensive curvatures arising and micro-roller processes arising are guaranteed to achieve a given homogeneity of the mixture and its stability.

If the technological process provides for the production of suspension with a large solid phase content (up to 40%) or it is necessary to obtain a highly resistant emulsion, or a thin suspension - resort to the mixing process of solid and liquid substances in a colloid mill (dispersant). A colloid mill allows not only to intensively mix particles and drops in suspension or thick emulsion, but also further crushes a solid fraction of suspension (emulsion drops) to size 1-2 micron, producing extremely high-quality suspensions and emulsions.

Homogenizer Colloid Mill

Constructively resemble rotary (centrifugal) homogenizers. Grinding a solid fraction in a colloid mill occurs, the so-called wet method. The main working organ of the colloid mill, like a homogenizer, is a pair of working disks equipped with a proper form. One of the disks acts as a stator, another rotor. In this case, the linear speed of the surface of the rotating disk can reach 125 m / s, which provides intensive turbulent and shock-cavitation processes in the interdiscable space, contributing to the effective grinding of the dispersed phase and its uniform distribution in the dispersed medium.

Practice has shown that today, colloid mills are able to provide the highest degree of dispersion and emulsification that meets the requirements of the overwhelming majority of industrial technological processes.

Homogenizer is a device for obtaining homogeneous (homogeneous) dispersed systems. Systems can be single or multiphase, i.e. In a dispersed medium, which is usually liquid, there are particles (usually insoluble) of one or more solid or liquid substances, which are called dispersed phases. The term "homogeneous" means that the phases are distributed evenly, with the same concentration in any arbitrarily taken unit volume of the medium. The resulting system must be relatively stable. For this, during homogenization, in the overwhelming majority of cases, dispersion is carried out, that is, the grinding of particles of the phase.

The use of homogenizers in the dairy industry

Homogenizer for milk crushes fat balls. The speed with which they pop up to the surface depends on the square of their radius. Thus, after a decrease of 10 times, the speed falls 100 times. Due to this, the product does not defend, not divided into cream and reverse. The term of its storage increases significantly.

In addition, after homogenization:

• In the manufacture of margarine or butter, water and other components are uniformly distributed in a fat medium. And in mayonuz and salad gas stations - fats in the aquatic environment.
• Cream and pasteurized milk are made homogeneous in color, taste and fatness.
• In condensed milk canned food, during long-term storage, the fat phase is not highlighted.
• Kefir, sour cream and other fermented milk products stabilize. The consistency of protein bunches is improving. The surface does not forms a fat traffic jam.
• In dry solid milk, the amount of free fat is not protected by the protein sheath. Due to this, its rapid oxidation is eliminated under the influence of atmospheric air.
• Milk with cocoa or other filler improves taste, it becomes more viscous. The probability of precipitate is reduced.
• In restored fermented milk drinks, cream and milk there is no watery taste. Natural taste becomes more saturated.

Physical methods of the process and the main types of homogenizers

• Purchase through a narrow gap. Valve type aggregates are used with high-pressure plunger pumps. Such devices in the dairy industry are the most common.
• Mechanical mixing. Mixers with knives or blades, including highly engaged, are used. The simplest example is a coffee grinder or a meat grinder with an electric drive. This can also include rotary and pulsation devices (RPA). Although they have a more complex effect on the phase lumps, it is not limited to shock and abrasive loads.
• Impact ultrasound. Uz-installations are operating, exciting cavitation in the dispersed medium, due to which the phase is crushed.

Plunger homogenizer

Device

The device of the homogenizer is shown in Fig. 1. Plunger cylinder 1 is connected to the inlet nozzle through the suction valve 3, and with a high pressure chamber - through the injection valve 4. From the camera there is a channel to a homogenizing head 5, which has a saddle 6, valve 7, spring 8 and adjusting screw 11. For Pressure control, the camera is connected to the camera 10. The channel has a branch on the safety valve 9. The plunger is driven by pump 2.

In the consolidated form, the homogenizing head is shown in Fig.2. It has a calibrated hole (channel) 1 in the saddle 5, spring 2, valve 4 with a rod 3 and an adjusting screw 6. The saddle and valve are fitted to each other.

The valve has a flat, cone with a small angle or a plate shape of the working surface. In the first case, it may be rhyled (grooves). If they are, then on the saddle are made the same. It increases the degree of crushing phase.

There are models in which the valve and saddle are located in the bearings installed in the stationary case. In this case, they, under the pressure of the jet of the product, rotate in different directions.

Since the fluid passing at high speed is quite strong on the valve and the saddle, they are rapidly wear out. Therefore, the specified elements are made of particularly durable steels. In addition, their form is symmetrical. With noticeable wear, it is enough to turn them over the other direction, thereby increasing the service life twice.

The pump is not necessarily a plunger, you can choose a screw or rotary. The main thing is that it creates high pressure. Since the plunger mechanism does not provide uniform feed, then in homogenizers put them several pieces, with the separation of the beginning of the cycles in time. The most popular are three permanent units. In them, the knee was turned on 120 degrees, so that the cylinders worked alternately. In this case, the feed unevenness coefficient, that is, the ratio of its maximum value to the average is 1.047.

Close to one indicator means that the flow running through the homogenizing head can be considered stable with a small error. Thus, in the process of homogenization, the valve is located all the time in the suspended (open) position. Between it and the seam there is a slot for the passage of liquid. Its size can also be taken permanent, without considering a minor deviation from the average level. Many modern devices have a stream from each plunger on "its" head. After crushing the phase, they are connected in the output manifold.

The pressure gauge is equipped with a throttling device. This reduces the oscillations of the arrow of the device.

Operating principle

The principle of operation of the homogenizer is next. When the plunger runs on the absorption (in the figure - moves to the left), the milk enters the cylinder 1 through the valve 3. Then the plunger runs on the injection (moved to the right) and pushes the product into the camera through the valve 4. After that, the channel fluid hits from the chamber to homogenizing Head 5.

When the valve is in a non-working position, the spring 8 tightly presses it to the saddle. The milk incoming under pressure lifts the valve so that a small slot is formed between it and the saddle. Passing through it, fat balls are crushed, the product is homogenized, after which it goes into the outlet.

The gap typically has no more than 0.1 mm. Milk particles move in this zone at a speed of about 200 m / s (in the discharge chamber - only 9 m / s). The size of fat lumps decreases with 3.5-4.0 μm to 0.7-0.8 microns.

Pressure created by a plunger pump is very large. Therefore, the channel clogging in the saddle can lead to the destruction of parts. To avoid breakage, a safety valve is set 9.

Adjust the unit 11. One of the main characteristics of homogenization is pressure. When tightening the screw, the spring clips the valve to the saddle stronger. Because of this, the size of the slit is reduced, as hydraulic resistance increases. The setup of the device is carried out according to the testimony of the pressure gauge 10.

According to the instructions for the homogenizer, the milk temperature should be between 50 to 65 degrees C. If it will be lower than this range, the process of settling fat lumps is accelerated. If above - serum proteins will be deposited.

The increase in the acidity of the product adversely affects the efficiency of the process, since in this case the stability of proteins is reduced. Agglomerates are formed, the crushing of fatty lumps is hampered.

At the time of the passage of fluid through the valve slot, due to the sharp narrowing of the transverse section of the channel, the effect of throttling is observed. The flow rate is repeatedly increasing, and the pressure drops due to the fact that the potential energy is converted into kinetic.

After passing the milk through the head, some part of the crushed particles again sticks out into larger conglomerates. The efficiency of the process falls. To combat this phenomenon, two-stage homogenization is used. The device is shown in Fig. 3. The fundamental difference from the single-stage is the presence of two pairs of working bodies, the first stage 4 and the second - 12. Each has its own pressure spring with a regulating valve 6.

The second stage, auxiliary, further increases the degree of crushing phase. It is designed to create a managed and constant backpressure in the head of the first stage, which is the main one. This optimizes the conditions of the process. As well as for destruction relatively unstable formations. The pressure in it is set to smaller than in the first one.

Single-stage homogenization is designed for low fatty products or high viscosity. Two-stage - as high content Fat or dry substances and low viscosity. And also in cases where it is necessary to ensure the maximum possible crushing of the phase.

Separate technology

In the dairy industry, homogenization can be complete or separate. In the first case, all available raw materials are passed through the aggregate. In the second, it first separate. The resulting cream 16-20% is homogenized, after which they mix with rerox. And they are sent to the next stage of recycling. This method gives significant energy savings.

The phase dispersion mechanism in the valve type apparatus

According to N. V. Baranovsky, on the basis of the study of hydraulic factors affecting the crushing of fatty lumps in the homogenization of milk on the valve type apparatus, the following process circuit was proposed (Fig. 4).

At the flow point of the flow from the channel of the saddle in the gap, the area of \u200b\u200bthe flow cross section is sharply reduced between the saddle and the valve. So, according to one of the basic laws of hydraulics, the rate of its movement U is also growing rapidly, if more specifically, the U0 is on the approach several meters per second. And U1 at the entrance to the slot - 2 orders of magnitude higher, several hundred m / s.

The fat drop does not switch from the zone small in the zone of high speeds simultaneously "all at once." In the stream moving into the gap with a huge speed, first includes the front of the ball. Under the action of a rapid fluid, it is pulled out (the back is still moving slowly) and leaves. The remaining lump continues leisurely (of course, the concept of "leisurely" in this case is relative, since the whole cycle of droplets through the gap takes 50 microseconds) to move towards the velocity section of the velocity, and part, now the front, is drawn up the same as the previous one, and also breaks away. Thus, the entire fat drop is gradually breaking into pieces, passing through the border cross section. This occurs at a sufficiently large difference in the speeds U0 and U1.

If the specified difference is less than a certain threshold, then, before the separation of the particles, the intermediate stage takes place - the drop is first stretched into the cord. If the difference is even smaller, the fatty lump will be held through the border of the velocity section without destruction. But the impact of high flow rate will still lead it to an unstable state, due to the formation of internal deformations. Therefore, due to the forces of the surface tension and mechanical blows of the stream stream, the ball will still seine the smaller fractions.

Homogenizer for oil

To obtain a homogeneous consistency of butter or melted cheeses, a homogenizer plasticizer is used. In the processing process, the aqueous phase is dispersed and evenly distributed throughout the volume. As a result, the product is stored longer, its taste is improved. In addition, the costs of time for defrosting are reduced, water loss is reduced when packaging.

The device of the device can be viewed by the example of one of the most popular models of M6 OG (Fig. 5). It consists of a housing and bed (Fig. 6), a receiving bunker, under which the feeds are located, and the rotor from the 12th, 16 or 24 blades. An electric motor is used as the drive. The screw rotation frequency is regulated by the variator. The angular speed of the rotor is constant.

The operation of the homogenizer is as follows. Creamy oil large slices placed in the bunker. The augers rotate in different directions, if you look from above - one towards another. With their help, the oil is pushed through the rotor, after which, through the nozzle of the rectangular section, it goes into the receiving hopper (not shown in the figure). In order for the oil to do not stick to the working bodies, they are lubricated by a hot solution. Motor-russia

Recently, rotary and pulsation devices (RPA) are increasingly used for milk processing. Such a homogenizer according to the design and the principle of action is similar to the centrifugal pump. The main difference is in the working bodies.

RPA is arranged as follows. The drive is the electric motor. The rotor is rigidly fixed on its elongated shaft in the form of a perforated cylinder. From the end of the cylinder, from the side of the lid, can stand the impeller. Perforation on it is not mandatory. Inside the lid there is a similar cylinder, fixed, it plays the role of a stator.

Milk is served through the axial nozzle on the lid and hits the impeller. This item produces the primary crushing of the phase and gives the working mixture acceleration. The latter then passes through the perforation of the movable cylinder, is again partially dispersed, under the action of cut and abrasive loads, and it turns out in a homogenizing cavity between the rotor and the stator. Here, besides the drums, there are also other forces on fat balls.

In a turbulent stream, moving at high speed (this is such a thing in the working area of \u200b\u200bthe RPA), microvaic flows arise. If a small spherical whirlpiece faces a drop of fat, he destroys it. There is also a hydroacoustic effect. Intensive cavitation, leading to the collapse of air bubbles, generates shock waves, against which the lumps of the phase also cannot resist.

The maximum effect of the device on the particles is achieved at the moment when resonant oscillations occur between the rotor and the stator. To provide this effect, It is necessary to calculate the diameter of the movable cylinder, the speed of its rotation, as well as the gap between it and the stator.

After the working area, the milk passes through the holes of the stator and, already homogenized, is displayed through the tangential exhaust pipe, directed usually upwards to easily connect pipelines to re-load the bunker in the recirculation system.

To increase the degree of crushing, there may be several pairs of "rotor-stator" in the apparatus. After installing the lid, they are arranged alternately. There are models in which, instead of an impeller, a perforated disk is put. RPA homogenizers can also be submersible. Optionally, the unit is equipped with the following fixtures:

• Protection against dry start.
• Explosion-proof engine.
• Housing with heating / cooling shirt.
• Smooth change control of the motor rotation frequency.
• The loading device (auger feeder), for viscous, poorly soluble, inhomogeneous emulsions and suspensions or bulk components.
• Unloading unit, for a drain in a body capacity when working on a circulation diagram.
• Facial bellows sealing shaft from carbido-silicon ceramics - increases the service life of the unit, even when working with liquids with aggressive or containing abrasive inclusions.

RPA is one or three-phase. All parts that come into contact with food products are made of AISI 304 food stainless steel, AISI 316 or their domestic analogs. Since the dispersed fluid comes out of the pressure unit, the RPA homogenizer simultaneously works as a centrifugal pump.

Ultrasound homogenizers

Device (on the example of Bandelin). The ultrasound homogenizer consists of (in Fig. 15 - from top to bottom) of the RF generator, the Uz-converter, "horns" and probes (waveguides). The RF generator is included in the domestic network with a current 50 or 60 Hz. It enhances this parameter to 20 kHz. Uz-converter, equipped with an oscillating diagram with a measuring piezoelectric element, transforms the generated by the generator current into oscillations of the waves of the same frequency. The generated amplitude remains constant. Ultrasound - increases, due to the use of "horns" of a special form. The probes transmitting fluctuations in the vessel with liquid are inserted into them. Depending on the volume of the working medium, they can be flat, in the form of cones or "micro", with a diameter of 2 to 25 mm.

The domestic industry also produces ultrasound homogenizers. From the last models, you can mention the development of 2015 and 100-6 / 840 (Fig. 16). The device has digital control, pulse mode, amplitude control and probe set.

Operating principle. When the tongs of waves pass through the liquid, they alternately, 20,000 times per second, create in it, then high, then low pressure. The latter is almost equal equal to the inner pressure of the vapor of the liquid, as a result of which bubbles filled with steam appear in it, the liquid boils. When the voids are collapsed, the pressure drop occurs, rapidly flowing turbulent microflows that destroy fat drops are formed.

Some experts believe that, under ultrasound exposure, lumps are dispersed not from cavitation, and due to the fact that the wave passing through a fatty drop at different points, causes various in size and direction of acceleration. As a result, multidirectional forces arise, trying to break the ball.

Homogenization is an important stage of the process of processing milk and other products. With its help, the structure is improved and the shelf life increases, and taste quality becomes more saturated.