RU2689672C1 - Method for complex processing of soya seeds with separation of protein-containing fractions - Google Patents

Abstract

FIELD: food industry.SUBSTANCE: invention relates to food industry and agriculture and may be used for complex processing of soya. Method comprises preparation of heat carriers using a steam ejector heat pump, comprising a steam generator with heating elements and a safety valve, ejector, cold receiver, two-section condenser, thermoregulating valve, condensate collector and evaporator operating in closed thermodynamic cycle. Method comprises drying soya seeds, drying dried seeds mechanically with soya bean oil as ready products; cooling pomace with cold air, its milling, mixing with water and heating in a vessel with a vibrated mixer. Also, produced mixture is divided into vibrating sieve into soluble and insoluble protein-containing fractions, removed dried insoluble fraction, purified in cyclones, cooled and dried in evaporator mixture of waste drying agents and air.EFFECT: use of the invention will make it possible to increase environmental safety of complex processing of soya with extraction of protein-containing fractions.1 cl, 1 dwg

Description

The invention relates to the integrated processing of soybeans and can be used in the food industry and agriculture.

Known production line of vegetable oil (US Pat. RF №2595152; IPC SV11 1/06; publ. 08/20/2016), including a dryer, roller machine, separator machine, fryer, forpress, filter press, expozitor, cyclone, heat exchanger-heat exchanger and steam-pressing heat pump, which provides preparation of superheated steam for roasting oilseeds with repeated use of superheated steam in the recirculation circuit and removal of part of the superheated steam from the recirculation loop in the amount of moisture evaporated from the seeds to the heat exchanger-heat exchanger p for heating the conditioned air directed to drying the seeds to form a closed thermodynamic cycles for material and heat fluxes.

Despite the attractiveness of the well-known line, it rather broadly generalizes the proposed method for the production of vegetable oil from oilseeds, extending it to various crops, whereas each oil-bearing crop has specific features both in composition, thermophysical, physicomechanical, aerodynamic characteristics, and in target purpose of the products obtained. The use of superheated steam for roasting seeds cannot be considered economically viable, and its rational use requires complete balance with the preparation of air for the implementation of pre-drying of seeds. Spent overheated steam after roasting may not be enough to prepare the air given temperature potential necessary for drying the seeds, which will lead to disruption of technological regimes in the field of permissible properties of the resulting vegetable oil.

The closest in technical essence and the achieved effect is a method of complex processing of soybean seeds (US Pat. Of the Russian Federation No. 2640366; IPC A23L 5/00; publ. 12.28.2017), which includes drying of soybean seeds in a drum dryer at a drying agent temperature of 80-85 ° С up to 10-12% humidity; mechanical pressing of dried seeds in a screw press with the output of soybean oil as finished products; cooling the squeeze with cold air in a gravitational cooler to a temperature of 10-15 ° C, grinding it in a roller mill to a fraction of 50 microns or less, mixing with water and heating to a temperature of 51-60 ° C in a tank with a vibrating mixer placed in it; the separation of the mixture on the vibrating screen into soluble and insoluble protein-containing fractions; removal of an insoluble fraction dried in a drum dryer with a moisture content of 7-10%; cyclone cleaning, cooling and drying in the evaporator a mixture of spent drying agents and air; removal of condensate to the condensate collector; heating the drying agent and water in the sections of a two-section steam ejector heat pump condenser with the formation of closed thermodynamic cycles on the material and heat fluxes. Adopted as a prototype.

However, the use of vapor compression heat pump in a known method is associated with the use of toxic refrigerants, which may affect the environmental safety of food technology. The presence of the piston system of the compressor requires planned stops for preventive maintenance and unscheduled for possible failures in the mechanical drive. To implement the method uses expensive equipment with significant operating costs and a very long payback period, which will lead to an increase in the cost of the products obtained. In addition, in the absence of heat sources in conditions of decentralized heat supply systems, when heat energy is generated directly at oil seed processing facilities, it is advisable to use a steam-ejector heat pump. In this case, it becomes possible to use the heat of low-temperature potential, in particular, waste heat of gas-turbine plants and boiler units, which makes it possible to effectively solve problems of energy saving.

An object of the invention is to improve the environmental safety of the method of complex processing of soybean seeds with the release of protein-containing fractions, improving the reliability of operation of the main and auxiliary equipment, reducing the cost of the resulting target and intermediate products due to maximum recovery and recycling of secondary energy resources using a steam ejector heat pump.

The technical goal is achieved by the fact that in the method of complex processing of soybean seeds with the release of protein-containing fractions, including drying of soybean seeds in a drum dryer at a temperature of the drying agent 80-85 ° C to a moisture content of 10-12%; mechanical pressing of dried seeds in a screw press with the output of soybean oil as finished products; cooling the squeeze with cold air in a gravitational cooler to a temperature of 10-15 ° C, grinding it in a roller mill to a fraction of 50 microns or less, mixing with water and heating to a temperature of 51-60 ° C in a tank with a vibrating mixer placed in it; the separation of the mixture on the vibrating screen into soluble and insoluble protein-containing fractions; removal of an insoluble fraction dried in a drum dryer with a moisture content of 7-10%; cyclone cleaning, cooling and drying in the evaporator a mixture of spent drying agents and air; removal of condensate to the condensate collector; heating the drying agent and water in the sections of a two-section steam ejector heat pump condenser to form closed thermodynamic cycles in material and heat flows, according to the invention, a steam generator with electrical heating elements and a safety valve, an ejector, a refrigerant receiver with a refrigerant recirculation refrigerant are also used, which are combined with a two-section condenser thermostatic valve, condensate collector and evaporator are assembled in steam ejector lovoy pump; in the steam generator, the working steam is obtained and is supplied under a pressure of 0.8-1.0 MPa to the ejector nozzle, thus creating a reduced pressure of 0.0009-0.001 MPa and a temperature of 4-7 ° C in the evaporator of a steam ejector heat pump with refrigerant recirculation through a cold-receiver; the mixture of refrigerant and working vapor after the ejector is supplied with a pressure of 0.1-0.2 MPa and a temperature of 105-120 ° C in the section of a two-section condenser for heating conditioned air and water; one part of the condensate formed after the two-section condenser sections is fed to the evaporator to replenish the loss of water, and the other part is discharged together with the condensate formed when the air is cooled in the cold-receiver in the form of dropping liquid, first to the condensate collector and then to the steam generator to form a closed cycle; At the same time, the flows of spent drying agents and air are combined and fed for drying into the cold-emitter of the steam-ejector heat pump, after which conditioned air with a moisture content of 0.010-0.0155 kg / kg and a temperature of 7-10 ° C is obtained, and part of the conditioned air is first heated in the section of a two-section condenser for heating conditioned air by recuperative heat exchange with a mixture of working and ejected vapors after the ejector, then sent as drying agents to lug soybean seeds and the insoluble fraction, and the remaining part of the conditioned air is sent into gravity cooler for cooling pomace to form the closed thermodynamic cycle.

The technical result of the invention is to improve the environmental safety of the method of complex processing of soybean seeds with the release of protein-containing fractions, to increase the reliability of equipment operation and reduce the cost of the target and intermediate products obtained using a steam ejector heat pump.

FIG. 1 shows a scheme that implements the proposed method of complex processing of soybean seeds with the release of protein-containing fractions.

The scheme contains drum dryers 1, 9; cyclones 2, 5, 10; screw oil press 3; gravity cooler 4; roller mill 6; a container with a vibrating mixer 7 therein; vibrating screen 8; steam ejector heat pump, which includes a steam generator 11 with a safety valve 12 and heating elements 13; ejector 14; section for heating air 15 and water 16 two-section condenser, installed in parallel; thermostatic valve 17; evaporator 18; cold receiver 19; pumps 20, 21, 22; condensate collector 23; fans 24, 25, 26, 27; flow distributors 28, 29, 30, 31; flows: 1.0 — initial soybean seeds into a drum dryer; 1.1 - dried soybean seeds in a screw press; 1.2 - pomace from the oil press to the gravity cooler; 1.3 - removal of soybean oil from the screw press; 1.4 - cooled husk for grinding in a roller mill; 7.5 - crushed marc for mixing with warm water in a mixer with a vibrating mixer; 1.6 - soybean suspension from the mixer on the vibrating screen; 1.7 - removal of the soluble fraction of soybean suspension by passing through a vibrating screen; 1.8 - insoluble fraction of soybean suspension descending from the vibrating screen for drying; 1.9 - dried insoluble fraction; 1.10-suspended solid particles from cyclones; 2.0 - drying agent from the condenser section for heating the air in the drum dryer; 2.1, 2.2, 2.3 - removal of spent drying agents through cyclones after drum dryers and exhaust air after gravity cooling, respectively; 2.4 - supply of spent drying agents and air to the cold receiver; 2.5 - conditioned air from the cold receiver to the gravitational cooler; 2.6 - conditioned air from the cold of the receiver to the condenser section for heating the air; 2.7 - recirculation of the refrigerant through the cold receiver; 2.8 - working steam from the steam generator; 2.9 - ejected vapor from the evaporator; 2.10 - mixtures of working and ejected vapors; 2.11 - condensate from the condenser section for heating water into the evaporator and the condensate collector; 2.12 - condensate from the cold receiver to the condensate collector; 2.13 - water from the condensate collector to the steam generator; 2.14 - pressure relief; 2.15 - water from the condensate collector to the condenser section for heating water; 2.16- supply of warm water to the mixer.

The method of complex processing of soybean seeds with the release of protein-containing fractions is as follows.

The original soybean seeds with an oil content of 19-22% and a protein content of 35-37% downstream 1.0 are fed to the drum dryer 1 and dried at a temperature of the drying agent of 80-85 ° C to a moisture content of 10-12%. The dried soybean stream 1.1 is sent to the screw oil press 3 and the oil is squeezed out with a yield of at least 35%, which is diverted through the stream 1.3 as the desired product. The obtained marc with a residual oil content of 8 ... 10% downstream 1.2 is sent to gravity cooler 4. The downs cooled down to 10-15 ° C are directed downstream 1.4 to the roller mill 6 and grind. When grinding occurs, the soybean extract is destroyed to a fraction of not more than 50 μm, with destruction of the cell membranes and self-heating of the mass due to friction forces to a temperature of 55 ° C. The result is soy flour with a protein content of up to 46%.

After grinding, the resulting mass in stream 1.5 is fed into a container with a vibrating mixer 7 placed in it and diluted with warm water with a temperature of 51-60 ° C. Extraction of proteins with water from crushed and defatted soybean seeds leads to the formation of a proteinaceous, homogeneous throughout the volume, soy suspension.

The resulting soybean suspension downstream 1.6 serves on the vibrating screen 8, where it is divided into fractions: soluble, with a protein content of 7.0-12%, and insoluble (Okara), with a protein content of 15.0-34.0%. By changing the ratio of components (crushed soybean and water squeeze), water temperature and mixing time, you can control the transition of protein and fat from the insoluble fraction to the soluble one, thereby either increasing the amount of protein in the solution or leaving it in the insoluble fraction.

The soluble fraction of the soybean suspension as an intermediate protein-containing product is taken downstream 7.7 and further used in fodder production in the preparation of feeding rations for farm animals. The insoluble fraction of soybean slurry (okara) through the stream 1.8 is fed to the drum dryer 9 and its moisture is adjusted to 7-10%, which is fed to storage and then used in the confectionery industry, as well as in feed rations for farm animals.

Flows 2.1 and 2.2 waste drying agents after drum dryers 1 and 9, as well as the flow of 2.3 exhaust air after the gravitational cooler 4 is cleaned, respectively, in cyclones 2, 10 and 5 from suspended solids, are combined into stream 2.4 and the fan 27 is sent to the cold-receiver 19 steam ejector heat pump.

The steam ejector heat pump operates according to the following thermodynamic cycle.

In the steam generator 11, by means of heating elements 13, working steam with a temperature of 86-90 ° C and under pressure of 0.06-0.07 MPa is supplied to the nozzle 14 of the ejector 14 under the pressure of 0.06-0.07 MPa, drawing the ejected refrigerant vapor as line 2.9. , from the evaporator 18 and create in it a reduced pressure of 0.0009-0.001 MPa with a refrigerant boiling point of 4-7 ° С, maintaining the ejection coefficient of the steam ejector heat pump in the range of 4-5. The refrigerant through the pump 20 circulates in the recirculation circuit 2.7 through the cold receptacle 19, in which the air is cooled to the “dew point” temperature through regenerative heat exchange, and the moisture contained in the air is condensed in the form of droplet liquid and drained along stream 2.12 to the condensate collector 23 .

Formed after the ejector 14, the mixture of ejected and working steam in the flow 2.10 through the distributor of the flow 29 is directed to sections 15 and 16 of the two-section condenser.

Formed after sections 15 and 16 of a two-part condenser, water condensate is divided into two flows 2.11 by means of flow distributor 30, one of which is directed through thermostatic valve 17 to evaporator 18 to replenish water loss in it, and the other excess condensate is drained. From the condensate collector, water is supplied by pump 22 along stream 2.13 to steam generator 11 with the formation of a closed cycle and downstream 2.15 - into section 16 of a two-section condenser for heating water, followed by feeding n Sos 21 warm water with a temperature of 55-65 ° C with mixing to squeeze in a container placed therein vibromeshalkoy 7. When the steam pressure in the steam generator 11 is increased more than 0.07 MPa, the safety valve 12 is activated, carrying out the release of pressure downstream of 2.14.

The resulting conditioned air in the cooler 19 is divided into two parts by means of the flow distributor 31, one of which is fed to the section 2.6 for heating the air 15 of the two-section steam ejector heat pump condenser 2.6 and heated to a temperature of 80-85 ° C by recuperative heat exchange with the working mixture and ejected vapors after the ejector 14, and then, as drying agents, are sent by fans 24 and 25 through streams 2.0 to dry the soybean seeds and the insoluble fraction, respectively, into tumble dryers 1 and 9. Oc The fallen part of the conditioned air downstream from the cold-cooler 19 downstream 2.5 is directed by the fan 26 to the gravitational cooler 4 to cool the squeeze to 10-15 ° C with the formation of closed thermodynamic cycles.

The proposed method of complex processing of soybean seeds with the release of protein-containing fractions is implemented on an experimental production line with a capacity of 7-10 t / h under the production conditions of Voronezh Experimental Feed Mill Plant with the following characteristics of a steam ejector heat pump:

The design of a steam-ejector heat pump does not contain moving wear parts, which ensures its trouble-free operation with long cycles without direct maintenance, while minimizing the amount of maintenance, cost, and the need for spare parts and auxiliary materials.

The rational use of heat and electricity in the cooling and heating system using a steam ejector heat pump was considered from the point of view of reducing the cost of the resulting target and intermediate products. The main fundamental solution for reducing energy consumption in the proposed method of complex processing of soybean seeds with the release of protein-containing fractions is the optimal choice of temperature drops in the evaporator and sections of a two-section condenser when receiving drying agents, cooling air and warm water. Deviation from these values will inevitably lead to an increase in energy consumption: lowering the boiling point of the refrigerant in the evaporator by 1 ° C will result in the need to increase the flow of working steam to the ejector of a steam ejector heat pump and, consequently, to an excess of energy by 5-7%, and an increase in condensation temperature by 1 ° C will lead to an increase in energy consumption by 2.0-2.5% ("Thermal and structural calculations of refrigerating machines" / EM Bambushek, NN Bukharin, E. Gerasimov, etc. L. 1987, pp. 85-93).

The proposed method of complex processing of soybean seeds with the release of protein-containing fractions expands the boundaries of energy-efficient coupling of objects of different temperature potentials based on the utilization and recovery of secondary energy resources. At the same time, a universal approach to the creation of a competitive technology that generates heat and cold for the joint processes of drying soybean seeds and the insoluble fraction of soybean suspension, cooling the squeeze and mixing it with warm water is fully implemented.

Thus, the proposed method of complex processing of soybean seeds with the release of protein-containing fractions has the following advantages compared with the prototype:

- creates environmentally safe conditions for the implementation of the method through the use of water as a refrigerant, eliminating the use of toxic, explosive and flammable working environments, as well as through the organization of closed recirculation schemes for material and energy flows with a significant reduction in the diversion of secondary energy resources from the heat and cold supply;

- provides an increase in the energy efficiency of the method due to the low-temperature potential of the refrigerant in the cold-receiver during air drying, as well as due to the heat of condensation of the refrigerant in the sections of the two-section condenser when the conditioned air is heated and then fed as a drying agent, as well as preparing warm water with the subsequent supply mixing with squeeze;

- water vapor with a pressure of 0.05-0.06 MPa is used as a working medium, which results in saving energy, which is spent only on the operation of controls, refrigerant and water pumps, heat-heating elements of the steam generator;

- allows you to reduce specific energy consumption by 5-7% due to the use of steam ejector heat pump, and, as a result, to reduce the cost of the target and intermediate products.

Claims (1)

The method of complex processing of soybean seeds with the release of protein-containing fractions, including drying of soybean seeds in a drum dryer at a drying agent temperature of 80-85 ° C to a moisture content of 10-12%, mechanical pressing of dried seeds in auger oil press with output of soybean oil as a finished product, cooling squeezing with cold air in a gravitational cooler to a temperature of 10-15 ° C, grinding it in a roller mill to a fraction of 50 microns or less, mixing with water and heating to a temperature of 51-60 ° C in a tank with a vibrating mixer placed in it d, separation of the resulting mixture in vibrating screens into soluble and insoluble protein-containing fractions, removal of an insoluble fraction dried in a drum dryer with a moisture content of 7-10%, cleaning in cyclones, cooling and drying in an evaporator of a mixture of spent drying agents and air, removal of the condensate formed into a condensate collector , heating the drying agent and water in the sections of a two-section steam ejector heat pump condenser with the formation of closed thermodynamic cycles in material and heat flows, differ In the course of processing, an additional use is made of a steam generator with electric heating elements and a safety valve, an ejector, a cold receiver with a refrigerant recirculation pump, which, together with a two-section condenser, a thermostatic valve, a condensate collector and an evaporator, are assembled in a steam-ejector heat pump; serves under pressure of 0.8-1.0 MPa to the ejector nozzle, this creates a reduced pressure of 0.0009-0.001 MPa and a temperature of 4-7 ° C in the evaporator p rojector jet heat pump with refrigerant recirculation through a cold receiver, supplying a mixture of refrigerant vapor and working steam after an ejector with a pressure of 0.1-0.2 MPa and a temperature of 105-120 ° C in a two-section condenser section for heating conditioned air and water, one part of condensate formed after the two-section condenser sections are fed to the evaporator to replenish the loss of water, and the other is taken away along with the condensate formed when the air is cooled in the cold-receiver in the form of a dropping liquid and, first in the condensate collector, and then in the steam generator with the formation of a closed cycle, while the flows of spent drying agents and air are combined and fed to the cold receiver of the steam ejector heat pump for drying, after which receive conditioned air with a moisture content of 0.010-0.015 kg / kg and temperature 7-10 ° C, and part of the conditioned air is first heated in the section of a two-section condenser for heating the conditioned air by recuperative heat exchange with a mixture of working and ezhe Convertible vapor after the ejector is then sent as a drying agent to dry soybean seed and an insoluble fraction, and the remaining part of the conditioned air is sent into gravity cooler for cooling pomace to form the closed thermodynamic cycle.

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