RU2278895C2 - Method of cryogenic refrigeration of the oils and the installation for its realization (versions) - Google Patents

Abstract

FIELD: fat-and-oil industry; methods and devices of cryogenic refrigeration of the oils.

SUBSTANCE: the invention is pertaining to the field of fat-and-oil industry. The method of cryogenic refrigeration of the oils provides for refrigeration, crystallization of the waxen substances with utilization of the vapors of the cryogenic agent and stirring, seasoning, heating up and filtrating of the oils. At that the stirring is conducted with formation of the rarefaction areas, in which the cryogenic agent is directly fed for refrigeration of the oil. And the waste vapors of the cryogenic agent after the crystallization of the waxen substances in the oil purified, separated and concentrated by the baromembrane methods are used as the inert gas at storing the oil. The installation includes arranged along the run of the production process components: pumps, the tank for the purified oil, the heat-exchangers, the refrigerator, screens, the sediment collector, the intermediate collector, the mixer, the heater and the cryogenic crystallizer. Behind the heater there are additionally in series mounted the compression pump, the membrane-type generator and the filling device for filling the oils in the leakproof tare. In the first version the cryogenic crystallizer with the heat-insulation is made in the form of the closed cylindrical body having: the tangentially located to it branch-pipe for the oil feeding, inside which there is the coaxially located fitting pipe for the liquid cryogenic agent feeding; the conical detachable cover; the conical bottom and arranged along the run of the production process - the hydrocyclone, the clarifier in the fluidized layer, the settling tank, the thin layer multihydrocyclone made out of the coaxially arranged plates, the clarifier in the fluidized layer, the forced settler-separator, the aerator-flotation device-hydrocyclone, the coalescing screen and the flotation chamber formed by the conical detachable cover, in the upper part of which there is the vacuum filter. The vacuum filter represents the drum, the filtration surface of which is made out of the metal-ceramics, above which there is the knife. At that inside the drum there are partitions connected with the hollow shaft linked by the system of the pipelines with the branch-pipes used accordingly for feeding of the gaseous cryogenic agent in the coalescing screen and in the clarifier. At that the clarifier is located in the fluidized layer behind the coalescing screen. The aerator-flotation device-hydrocyclone are supplied with the branch-pipes with screens, and the settling area collector of the coalescing screen - with the branch pipe without the screen. In the second version the crystallizer with the heat-insulation is made in the form of the oval-shaped body with the inlet and outlet branch-pipes with the screens. In the upper part of the conical detachable cover of which there is the vacuum filter and inside the body there is the two-blade stirrer fixed on the hollow shaft. At that the shape of the blades is precisely repeat the internal surface of the cryogenic crystallizer and have the holes located in symmetry on the both sides respect to the attached to their middle part perforated tubes for the cryogenic agent feeding and are placed so, that the areas of their operation are overlapping. At that the holes in the perforated tube there are only in its spherically bent part and are guided in the direction opposite to the direction of rotation of the stirrer. The invention allows to increase efficiency of the installation operation, to reduce the specific power consumption and costs of materials at utilization of the cryogenic agent and to ensure the high quality of the oil at storing.

EFFECT: the invention ensures the increased efficiency of the installation operation, reduction of the specific power consumption and the costs of materials at utilization of the cryogenic agent, the high quality of the oil at storing.

3 cl, 8 dwg

Description

The present invention relates to the refining of vegetable oils, namely to freezing (winterization) of wax substances.

The closest in technical essence and the achieved effect to the problem being solved is a method of freezing wax substances from vegetable oils (RF Patent No. 2180681 C 11 B 3/00, 11/00, 15/00. BI No. 8, 2002), including cooling vapors of a cryoagent, crystallization of wax substances, exposure, flotation of wax substances, heating and oil filtration.

A disadvantage of the known method of freezing wax substances from vegetable oils is the high specific material and energy costs when using cryoagents.

The closest in technical essence and the achieved effect is the installation for freezing wax substances from vegetable oils (RF Patent No. 2156280 C 11 B 3/00. BI No. 26, 2000), including pumps located along the process, a container for refined oil , heat exchangers, cooler, crystallizer, which uses a cryogenic apparatus, filters, sediment collector, intermediate collector, mixer and heater.

The disadvantages of this installation are the low efficiency of the mold and high specific energy and material costs when operating the unit using a cryoagent.

The closest in technical essence and the achieved effect is an apparatus for wastewater treatment from suspended solids and oil products (RF Patent No. 1674895, BI No. 33, 1991), including a hydrocyclone located in the process, a clarifier in a suspended layer, a thin layer side sedimentation tank , coalescing filter, 1st stage aerator-flotator, 2nd stage coalescing filter, 2nd stage aerator-flotator.

The disadvantage of this apparatus is the inability to use it as a crystallizer using a cryoagent.

An object of the invention is to increase the efficiency of the installation, crystallizer, reducing specific energy and material costs when using a cryoagent and ensuring high quality oil during storage.

The technical problem is achieved by the fact that in the method of cryogenic winterization of oils, including cooling, crystallization of wax substances using cryoagent vapors and mixing, exposure, heating and filtering of oil, new is that mixing during crystallization is carried out with the formation of rarefied zones, which are directly supplied cryoagent for cooling the oil, and the spent cryoagent vapors after crystallization of wax substances in the oil are purified, isolated and concentrated baromemb early methods are used as an inert gas during storage of oil.

In an installation for cryogenic winterization of oils, which includes pumps located in the process, a container for refined oil, heat exchangers, a cooler, filters, a sediment collector, an intermediate collector, a mixer, a heater and a cryogenic crystallizer, the compressor is additionally installed in series after the heater , a membrane-type cryoagent generator and a filling device for packaging oil in sealed containers, while the cryogenic mold with thermal insulation is it is a closed cylindrical body with a tangentially located oil supply pipe, inside of which a pipe for supplying a liquid cryoagent is coaxially placed, a conical removable cover, a conical bottom, and includes a hydrocyclone located in the process, a clarifier in a suspended layer, a thin-layer multi-hydrocyclone made of coaxially located plates, clarifier in a suspended layer, pressure settler-separator, aerator-flotator-hydrocyclone, coalescing filter and flotation a chamber formed by a conical removable cover, in the upper part of which a vacuum filter is provided, which is a drum, the filtering surface of which is made of cermet, over which the knife is located, while inside the drum there are partitions connected to a hollow shaft connected by a piping system with nozzles , respectively, the supply of gaseous cryoagent to the coalescing filter and to the clarifier, the clarifier in the suspended layer, after the coalescing filter and the aerator-flotator-hydrocycle n are equipped with nozzles with filters, and the collector of the settling zone of the coalescing filter is equipped with a nozzle without a filter.

In an installation for cryogenic winterization of oils, which includes pumps located in the process, a container for refined oil, heat exchangers, a cooler, filters, a sediment collector, an intermediate collector, a mixer, a heater and a cryogenic crystallizer, the compressor is additionally installed in series after the heater , a membrane-type cryoagent generator and a filling device for packaging oil in sealed containers, while the cryogenic mold with thermal insulation is made in the form of an oval-shaped case with loading and unloading nozzles, in the upper part of the conical removable cover of which a vacuum filter is provided, and inside there is a two-blade mixer mounted on a hollow shaft, while the blades exactly repeat the inner surface of the cryogenic mold, have holes located symmetrically with two sides relative to the perforated tubes for feeding the cryoagent attached to their middle part, and are arranged in such a way that their areas of action overlap, and the opening The ions in the perforated tube are located only in its spherically bent part and are directed in the opposite direction from the direction of rotation of the mixer.

The technical result consists in increasing the efficiency of the installation and the mold, reducing specific energy and material costs when using a cryoagent, as well as in ensuring high quality oil during storage.

Figure 1 shows a diagram of an installation for implementing the method of cryogenic oil virilization, figure 2 - a mold with a tangential oil supply, a cross section of a mold with a tangential oil supply along A-A, figure 3 is a diagram of the introduction of a liquid cryogenic agent and oil into the mold with a tangential oil supply, FIG. 4 is a vacuum filter of a crystallizer with a tangential oil supply, a longitudinal section along BB of a vacuum filter of a crystallizer with a tangential oil supply, FIG. 5 is a perspective view of a cryogenic crystallizer using 6, a cross-sectional view of the mixer along BB of the mold using mechanical stirring.

Installation of cryogenic winterization of oils (figure 1) consists of pumps 1, 3, 9, 12 and 14, capacity 2, heat exchanger 4, cooler 5, cryogenic crystallizer 6, filters 7, sediment collector 8, intermediate collector 10, mixer 11 and heater 13, a compressor 15, a membrane-type cryoagent generator 16 and a filling device 17 for packaging oil in an airtight container 18.

In this case, the cryogenic crystallizer 6 with tangential oil supply (FIG. 2) is a closed cylindrical body 19 with a conical removable cover 20 and a conical bottom 21 and includes a hydrocyclone 22 located in the process, a clarifier 23 in a suspended layer, a thin layer multi-hydrocyclone 24 made of coaxial located plates, clarifier in the suspended layer 25, pressure settler-separator 26, aerator-flotator-hydrocyclone 27, coalescing filter 28 and flotation chamber formed by a conical removable cr Arrow 20.

To supply oil to the cryogenic crystallizer 6 there is a pipe 29 tangentially located to it, inside which (Fig. 1,3) a pipe 30 is coaxially placed for supplying a liquid cryogenic agent (for example, nitrogen).

In the zone of liquid oil supply (Fig. 3), a glass 31 of food fluoroplastic is installed in order to prevent the formation of thickened oil growths on the walls of the apparatus body 19. In addition, it is proposed to cover the inner surfaces of the cryogenic crystallizer 6 in contact with oil, an organosilicon liquid, to prevent sticking of the product monoliths.

In order to exclude heat influx from the environment into the working area of the cryogenic crystallizer 6 and to avoid the formation of a snow coat, the apparatus is equipped with thermal insulation 32, which is an ATM-10s-20 mats made of superthin fiberglass.

For continuous drainage of frozen oil and cryoagent, a vacuum filter 33 is provided in the upper part of the conical removable cover 20 (Fig. 4), which is a drum 34, the filtering surface of which is made of cermet, and to ensure timely drainage of oil into the hollow shaft 36 there are baffles 35 Moreover, the hollow shaft 36 connected to a vacuum pump (not shown) is also connected by a piping system to a pipe 39 and 40 (not shown), respectively, supplying a gaseous cryoagent to a coalescing filter 28 and to a clarifier 2 3. To remove the layer of wax substances from the surface of the drum 34, a knife 37 is used. In this case, the vacuum filter 33 and the knife 37 are enclosed in a sealed casing 38.

To remove part of the frozen-out oil from the clarifier in the suspended layer 23, after the coalescing filter 28 and from the aerator-flotator-hydrocyclone 27, pipes 41, 43 respectively are used, in front of which filters 44 and 45 are installed.

To remove a suspension of oil with wax substances from the settling zone of the coalescing filter 28, a pipe 42 is used, connected to collectors (not shown) located in this zone.

In addition to the cryogenic crystallizer with a tangential oil supply in this installation, the proposed method can also be implemented in a cryogenic crystallizer using mechanical stirring (figure 5).

The cryogenic crystallizer 6 using mechanical stirring (Fig. 5) consists of an oval-shaped (or spherical) case 46, a loading 47 and an unloading 48 nozzles, a sampling valve (not shown). Inside the cryogenic crystallizer there is a two-blade mixer mounted on the hollow shaft 50. The mixer consists of blades 49, exactly repeating the inner surface of the cryogenic crystallizer, to which the perforated tube 51 for attaching the cryogenic agent is attached. The blades are arranged so that their areas of action overlap. The blades are made of a metal plate, in which, to turbulize the oil flow, holes 52 are made symmetrically on both sides relative to the perforated tube 51 attached in the middle of the blade 49. The holes 53 in the perforated tube 51 are located only in its spherically curved part (Fig. 5) and are arranged in two rows (the angle between which, for example, is 120 ° (Fig. 6, section BB)).

This arrangement of the holes in the blades 49 and the perforated tube 51 makes the process of mixing oil with a cryoagent as intense as possible, because the oil, passing through the holes 52 in the blades 49, changes its direction of movement, i.e. it is turbulized, at the same time it enters the zone of action of the cryoagent jets, mixing uniformly with it.

The agitator shaft 50 is driven from an electric motor (not shown) by means of a gear 54, a gear and a worm gear (not shown).

For the continuous removal of frozen oil and cryoagent, a vacuum filter 56 is provided in the upper part of the conical removable cover 55 (Fig. 5), the construction and principle of operation of which is similar to the vacuum filter 33 in Fig. 3.

The method of cryogenic winterization of oils in the installation is as follows.

To obtain salad oils, sunflower, corn, and sometimes partially hydrogenated soybean oils are frozen.

Ointments (freezing) are oils that have undergone a full cycle of food refining, before or after deodorization.

Oil pump 3 is fed into the regeneration heat exchanger 4, where it is cooled by frozen oil, then enters the cooler 5, in which the oil temperature drops to 4 ... 12 ° C, then sent to the cryogenic crystallizer 6 with a tangential oil supply (figure 2) or using mechanical stirring (figure 4).

Cryogenic winterization in the mold 6 with a tangential supply of oil (figure 2) is as follows.

First, to create conditions for better crystallization in the cryogenic crystallizer 6 by forming crystallization centers, a suspension is prepared in an amount of 3 ... 5% drainage material (for example, kieselguhr) to the mass of oil, for which filtered oil from the filters is fed into the mixer 11 (Fig. 1) 7 and drainage material (e.g. kieselguhr).

Pre-mixed oil with 0.05 ... 0.1% suspension, consisting of drainage material (for example, kieselguhr) and oil, after 5-10 minutes of contact using pump 12 is tangentially fed into the cryogenic crystallizer 6 (figure 2), where it acquires rotational motion in a hydrocyclone (flocculator) 22.

When the tangential supply of oil at high speed at the place of its entry into the hydrocyclone 22 (Fig.3), a vacuum zone (vacuum) is formed, into which a liquid cryoagent (for example, nitrogen) is supplied through the nozzle 30. In this case, under the action of vacuum, intense evaporation of the cryoagent (for example, nitrogen) and subsequent mixing of its vapor with oil moving along a spiral trajectory down into the conical part occurs. Heat is removed from the oil, its viscosity increases, and when the critical temperature is reached (for example, 4-12 ° C), the waxes crystallize.

Under the action of centrifugal forces, the suspension is separated here (oil up, wax substances with drainage material down), as well as further formation and enlargement of flocs (flocculus) of wax substances. Part of the frozen oil through the filter 45, the drainage layer (for example, kieselguhr) and the pipe 41 is removed outside the mold 6.

Further, the flow changes the direction of movement and, heading upward, enters the thin-layer multi-hydrocyclone 23 formed by coaxially arranged plates, the centrifugal force field is still strong here, and the separation of the volume into thin layers provides for a laminar flow motion mode.

Then the oil enters the clarifier in the suspended layer 25, where in the cylindrical part of the apparatus with a decrease in the velocity of the upward flow to 1 mm / s, the effect of the gravitational field is enhanced. Here, the suspended particles form a kind of filter - a suspended layer, and its separation by thin-layer plates, subject to continued flow rotation, also involves the separation of oil and wax substances due to centrifugal forces, i.e. the effect of separation of the suspension in a thin layer multi-hydrocyclone 24 continues.

After that, the suspension enters the pressure separator-wax separator 26, where the pop-up wax is displaced by the volume of the flotation chamber and accumulates on a limited free surface in a thick layer, from where it is discharged by the collector through the pipe 42.

Further, the flow again changes its direction and, moving downward, is tangentially introduced into the aerator-flotator-hydrocyclone 27, where, again acquiring a rotational motion, it encounters a counterflow of bubbles of refrigerant vapor (for example, nitrogen) from the combined gas mixture, which contributes to separation and flotation fine particles of wax substances. And part of the oil through the filter 44, the drainage layer (for example, kieselguhr) and the pipe 43 is removed outside the mold 6.

In the conical part of the aerator-flotator 27, the flow again changes its direction of motion and, moving upward, enters the coalescing filter 28. Here, finely dispersed particles of wax substances coalesce (coarsen on granules of the coalescing charge), and the resulting flocs float into the settling zone of the coalescing filter 28, from where are also diverted by the collector through the pipe 42.

Further, the flow enters the flotation chamber, where, through pressure flotation, the final purification of the suspension from the smallest particles of wax substances occurs. From the flotation chamber, through the vacuum filter 33, gaseous cryoagent (for example, nitrogen) and frozen-out oil are continuously discharged into the hollow shaft 36. A part of the gaseous cryoagent (for example, nitrogen) is supplied through pipelines through the pipe 39 to the coalescing filter 28 to provide the effect of oil gas lift with wax substances.

The resulting layer of wax substances on the ceramic-metal surface 34 of the drum is removed with a knife 37, which are then sent to feed targets.

The process of winterization in a cryogenic crystallizer 6 using mechanical stirring is as follows.

Before starting work, the drain fitting 48 is closed and a cryogenic gas (for example, nitrogen) is supplied to the cryogenic apparatus to displace air from its casing 46 through the perforation 53 in the cryogen supply tubes 51. After the cryogenic apparatus is filled with vapors of a cryoagent (for example, nitrogen), oil mixed with 0.05 ... 0.1% suspension consisting of a drainage material (for example kieselguhr) and oil is fed through it to pipe 47 the drive shaft 50 of the mixer is switched on. When the mixer moves, the product passes through the openings 52 in the blades 49 and its movement is turbulent, which intensifies the mixing process, at the same time, rarefaction zones are formed behind the blades 49 (Fig.6, section B-B) and a liquid cryoagent is supplied under pressure ( for example, nitrogen) in the opposite direction from the direction of rotation of the mixer, which saturates the oil. During the mixing process, the supply of cryoagent does not stop, which performs two functions: aeration of the oil (which then favorably affects storage) and maintaining the required crystallization temperature in the apparatus body 46.

A cryoagent (for example, nitrogen) is supplied from a storage tank (tank type TRZHK-2U) under pressure (for example, 0.25 MPa), which prevents oil from entering openings 53 in combination with a vacuum during rotation of the mixer.

As a result of evaporation of the liquid cryoagent in the rarefied zone, heat is removed from the oil and waxes crystallize when the viscosity of the oil increases and the critical temperature is reached (for example, 4-12 ° C).

The resulting bubbles of the gaseous cryoagent, capturing the waxes, rise up to the vacuum filter 56, through which the gaseous cryoagent (for example, nitrogen) and frozen-out oil are continuously discharged into the hollow shaft. The resulting layer of wax substances on the ceramic-metal surface of the drum of the vacuum filter 56 is removed with a knife, which are then sent to feed targets.

Thus, the oil frozen from the cryogenic crystallizer 6 by the pump 14 is pumped through the heater 13 to the filters 7, in which it is possible to use the heat of the vapors of the condensed cryoagent (for example, nitrogen) to melt the waxes when cleaning the filters by sending these vapors to the heater 13, where the oil is heated with hot water up to 20 ° C, and a drainage layer is created on the filter.

Depending on the type of filters, the filtration pressure can be from 0.25 to 0.50 MPa, with increasing pressure, the filter press is turned off for cleaning. When cleaning the filters, the sediment is discharged into the collection 8. The sediment is used for feed purposes.

When filtering, the first turbid portions of oil are discharged into the mixer 11, and the transparent oil enters the intermediate reservoir 10, from where it is pumped through the heat exchanger 4 to the container 2 and pump 1 to the filling and capping device 17 for packaging the oil in an airtight container 18 in an inert gas environment (for example, nitrogen), which protects it from contact with oxygen, oxidation and thereby provides the necessary value of the peroxide value.

Moreover, as an inert gas (for example, nitrogen), spent cryoagent vapors are used after crystallization of wax substances in oil, purified from associated gases (primarily from atmospheric oxygen), isolated and concentrated by baromembrane methods using compressor 15 and generator 16.

In addition, during storage, a cryoagent (for example, nitrogen) is additionally released from the oil, saturated during aeration with stirring in a cryogenic apparatus and providing reliable conditions for long-term storage without contact with oxidizing media (for example, with oxygen). This is especially important for short-term depressurization of containers.

When performing cryogenic winterization, the filtered oil should be transparent and not cloudy at low temperatures (up to 5 ° C) for 24 hours.

The advantages of the proposed installation are as follows:

- the use of liquid nitrogen as a coolant allows to intensify the process of oil purification from wax substances;

- allows you to reduce the time for crystallization and exposure of oil with a decrease in the number of equipment for these processes;

- the implementation of mixing during crystallization with the formation of rarefied zones, into which a cryoagent is directly fed to cool the oil, allows to improve heat and mass transfer in the process of separation of wax substances from oil;

- the use of purified, isolated and concentrated by baromembrane methods spent cryoagent vapors after crystallization of oil as an inert gas during storage of oil allows to increase its shelf life with a stable peroxide value and reduce the cost of finished products;

- the installation of a membrane-type cryoagent after the heater, compressor and generator allows the qualitative separation of the spent refrigerant from oxygen in the air, and thus to eliminate the oxidation of the oil as a result of its contact with oxygen during bottling and subsequent storage in a sealed container or package;

- the use of the proposed designs of crystallizers for cryogenic winterization of oils can improve the quality of oils, increase the compactness of the apparatus and reduce the cost of obtaining a finished product of high quality.

Claims (3)

1. The method of cryogenic winterization of oils, including cooling, crystallization of wax substances using cryogenic vapor and mixing, exposure, heating and filtering oil, characterized in that the mixing during crystallization is carried out with the formation of rarefied zones into which the cryoagent is directly fed to cool the oil, spent cryoagent vapors after crystallization of wax substances in oil; refined, isolated and concentrated by baromembrane methods are used as inert gas storage oil. 2. Installation for cryogenic winterization of oils, including pumps located along the process, a container for refined oil, heat exchangers, a cooler, filters, sediment collector, an intermediate collector, a mixer, a heater and a cryogenic crystallizer, characterized in that a compressor is additionally sequentially installed after the heater , a membrane-type cryoagent generator and a filling device for packaging oil in sealed containers, while the cryogenic mold with thermal insulation is It consists of a closed cylindrical body having a nozzle for supplying oil tangentially located to it, inside of which a nozzle for supplying a liquid cryoagent is coaxially placed, a hydrocyclone located in the process, a clarifier in a suspended layer, a thin multi-hydrocyclone from coaxially arranged plates, a clarifier in a suspended layer, pressure settler-separator, aerator-flotator-hydrocyclone, coalescing filter and flotation chamber formed by a conical removable cover, in The upper part of which is provided with a vacuum filter, which is a drum, the filtering surface of which is made of cermet, over which the knife is located, while inside the drum there are partitions connected to the hollow shaft, connected by a piping system with nozzles respectively supplying a gaseous cryoagent to the coalescing filter and clarifier, moreover, the clarifier in the suspended layer after the coalescing filter and the aerator-flotator-hydrocyclone are equipped with nozzles with filters, and the collector settles zone coalescing filter pipe without filter. 3. Installation for cryogenic winterization of oils, including pumps located along the process, a container for refined oil, heat exchangers, a cooler, filters, sediment collector, an intermediate collector, a mixer, a heater and a cryogenic crystallizer, characterized in that a compressor is additionally installed in series after the heater , a membrane-type cryoagent generator and a filling device for packaging oil in sealed containers, while the cryogenic mold with thermal insulation is made in the form of an oval-shaped housing with loading and unloading nozzles, in the upper part of the conical removable cover of which a vacuum filter is provided, and inside there is a two-blade mixer mounted on a hollow shaft, while the blades accurately repeat the inner surface of the cryogenic mold, have holes located symmetrically on both sides relatively attached to their middle part of the perforated tubes for feeding the cryoagent, and are arranged in such a way that their areas of action overlap, and the opening Ia in a perforated tube located only in a spherically curved portion thereof and directed in the opposite direction from the direction of rotation of the agitator.

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