RU2721704C1 - Method for production of pellets from cake of oil seeds and device for implementation thereof - Google Patents

Abstract

FIELD: food industry.SUBSTANCE: invention relates to oil and fat and feedstuff industry. Method and device for production of pellets from seed cake of oilseeds provides for milling of cake, extraction of petals cake with hexane in a screw extractor, distillation of miscella and distillation of solvent from extraction cake with continuous removal of formed vapours in a vacuum evaporator, condensation of vapours of boiling hexane in recuperative heat exchanger due to recuperative heat exchange with low-potential steam, extrusion of extraction cake in screw extruder, cooling cake before grinding and pellets after extrusion of cooled air in air coolers, use of two-stage high-temperature steam compression heat pump to produce superheated steam in second stage condenser and its supply to heating jacket of extruder, removal of high-potential steam from heating jacket of extruder to heating chamber of vacuum-evaporator, removal of low-potential steam from the heating chamber of the vacuum evaporation apparatus into a recuperative heat exchanger with return to the second stage condenser to form a closed cycle; air cooling in first stage of evaporator to temperature of 14–16 °C, its supply to air coolers and through cyclone for air cleaning from suspended particles with return to evaporator of the first stage with formation of closed circuit.EFFECT: invention allows improving ecological safety at all stages of technological process and reducing emissions of waste heat carriers to ambient atmosphere, as well as reducing specific energy consumption during production of fodder pellets from press cake of oil crops seeds.2 cl, 1 dwg, 1 tbl

Description

The invention relates to a method for processing oilseeds and can be used in the oil industry.

Known methods for the preparation of feed pellets from oilseeds, which include heat treatment of oilcake, extraction of oil from oilcake by extraction, separation of insoluble residue and its heat treatment when producing granules by extrusion (RF Patent 2290833, A23K 1/14, A23L 1/20; RF Patent 2304417; , A23P 1/12, A23N 17/00), by molding and drying (RF Patent 2497381, A23K 1/14, A23K 1/16; RF Patent 2190334, A23L 1/20, A23J 1/14).

A common disadvantage of the known methods is that they do not implement the basic principles of energy saving associated with the organization of closed thermodynamic cycles with the possibility of recovery and utilization of secondary energy resources, which does not create real prospects for reducing energy costs per unit mass of obtained granules.

The closest in technical essence and the achieved effect is a method of processing oilseed material (RF Patent 2027746, С11В 1/10) according to the forpress-extraction scheme, including cleaning, caving, grinding, moisture heat treatment, oil extraction, extraction of the obtained cake in a vertical screw extractor with a temperature of 60 ... 100 ° C at a residual pressure of 70 ... 100 kPa, distillation of the miscella and distillation of the solvent from the meal with continuous removal of the vapors formed.

The main disadvantage of this method is the high heat energy costs associated with the irrational use of waste heat carriers and the lack of recycling of material and heat fluxes using heat pump technologies, in particular a vapor compression heat pump.

An object of the invention is to increase the energy efficiency and environmental safety of a method for the production of feed or fuel pellets from oilseeds due to the maximum recovery and utilization of secondary, energy resources, the implementation of closed thermodynamic cycles in material and heat flows using a high-temperature vapor compression heat pump.

This object is achieved by the fact that in the method for the production of pellets from oilcake oilseed, involving the production of vegetable oil and oilcake with the removal of oil for cleaning; grinding the cake to a size of 2-4 mm, extracting the petals of the cake obtained at a temperature of 90 ... 100 ° C and a residual pressure of 70 ... 100 kPa, distilling the miscella and distilling off the solvent from the meal with continuous removal of the vapors formed, according to the invention as an organic solvent for extracting vegetable oils use hexane, the temperature regime for the extraction of the petals of the cake obtained is carried out by means of regenerative heat exchange between the miscella and high-grade steam with a temperature of 120 ... 130 ° C; vapors of boiling hexane are condensed at a temperature of 69 ... 71 due to recuperative heat exchange with low-grade steam with a temperature of 40 ... 45 ° С; the meal obtained after extraction is extruded at a temperature of 195 ... 200 ° C, the temperature regime of which is ensured by regenerative heat exchange with superheated steam at a temperature of 205 ... 210 ° C, and the pellets before grinding and the pellets obtained after extrusion are cooled with cooled air to a temperature of 16 ... 18 ° C and 20 ... 22 ° C.

A known method of processing soybean and a set of means for its implementation (Pat. 2190334 RF, A23L 1/20, A23J 1/14), providing for the extrusion of oil in the press and grinding the squeeze in vibrating mills to a fraction of 50 microns. However, a set of means for its implementation does not allow to obtain pellets from oilseed meal.

A known line for the production of vegetable oil [US Pat. No. 2595152 of the Russian Federation, IPC С11В 1/06; Vegetable oil production line / Frolova L.N., Shevtsov A.A., Vasilenko V.N., Dragan I.V., Mikhailova N.A., Krivova A.S .; applicant and patentee Voronezh, state Univer. engineering technol. - No. 2015111115/06; declared 03/27/2015; publ. 08/20/2016, Bull. No. 23], including: a dryer, a roller machine, a separating machine, a fryer, prepress, a filter press, an expositor, a cyclone, a heat exchanger-recuperator and a vapor compression heat pump, which provides the preparation of superheated steam for frying oilseeds with repeated use of superheated steam in the circuit recirculation and removal of part of the superheated steam from the recirculation circuit in the amount of moisture evaporated from the seeds to the heat exchanger-recuperator to heat the conditioned air sent to dry the seeds with the formation of closed thermodynamic cycles in material and heat flows.

Despite the obvious advantage of the device for the operation of this line using a vapor compression heat pump, it does not provide for the production of pellets from oilcake.

The closest in technical essence and the achieved effect is a device for implementing the method of processing oilseed material (RF Patent 2027746, С11В 1/10), including forpress; roller mill; separation machine; flatting machine; vertical extractor; vacuum evaporator with a heating chamber and nozzles for supplying steam and exhaust steam; heat exchanger-recuperator with inlet and outlet pipes; collection of condensed solvent vapors.

A disadvantage of the known device is the inability to process oilseed meal to obtain pellets. This device is intended only to increase the concentration of miscella. It cannot be considered energy efficient, since it does not allow for the recovery and disposal of secondary energy carriers with subsequent reuse.

The objective of the invention is to provide a device for the production of pellets from oilseed oil cake using a vapor compression heat pump to obtain energy carriers of different temperature potentials, which reduces the specific energy consumption due to maximum recovery and utilization of waste heat carriers in closed thermodynamic cycles.

The problem is solved in that the device for the production of pellets from oilcake oilseeds, including forpress; roller mill; separation machine; flatting machine; vertical extractor; vacuum evaporator with a heating chamber and nozzles for supplying steam and exhaust steam; heat exchanger-recuperator with inlet and outlet pipes; collection of condensed vapors of hexane; according to the invention further includes a screw extruder with a heating jacket and nozzles for supplying superheated steam and removal of high-potential steam; air coolers with pipes for supplying chilled and exhaust air installed in front of the grinder and after the screw extruder; cyclone for air purification from suspended particles; forcing and exhaust fans for air; high pressure fan; a high-temperature two-stage vapor compression heat pump, including first and second stage compressors, a first stage evaporator with an inlet pipe for supplying exhaust air and an outlet pipe for discharging cooled air; a second stage condenser with a pipe for supplying exhaust steam and a pipe for supplying superheated steam to the inlet pipe of the heating jacket of the extruder; condenser-evaporator, which for the first stage is a condenser, and for the second stage an evaporator, thermostatic valves of the first and second stage; while the outlet pipe for exhausting the cooled air of the first stage is connected to the inlet pipes of the air coolers through the blower fan, and the pipes for the output of the air coolers are connected in series with a cyclone for cleaning air from suspended particles, an exhaust fan and with an inlet pipe for supplying exhaust air to the evaporator of the first stage with the formation closed loop; a second stage condenser superheater steam supply pipe is connected in series with a high-pressure fan, an inlet pipe of a heating jacket of an extruder, an outlet pipe of which is connected to an inlet pipe of a high-potential steam of a heating chamber of the evaporator; and the outlet pipe of the low-grade steam of the heating chamber of the evaporator is connected to the inlet of the regenerative heat exchanger; the outlet pipe of the spent steam of the regenerative heat exchanger is connected to the pipe for supplying the spent steam of the second stage condenser with the formation of a closed loop.

In FIG. presents a scheme that implements the proposed method for the production of pellets from oilcake oilseeds and a device for its implementation.

The circuit contains prepress 1; air cooler 2; roller machine 3; separation machine 4; flatting machine 5; vertical screw extractor 6, consisting of three columns: loading, extraction and horizontal, which is a transfer screw; vacuum evaporator 7 with a heating chamber; heat exchanger-recuperator 8; vacuum pump 9, a collection of condensed vapors of hexane 10; screw extruder 11 with a heating jacket; cyclone 13, exhaust 14 and forcing 15 fans; flow distributor 16; a high-temperature two-stage vapor compression heat pump, including compressors of the first 17 and second 18 stages, an evaporator of the first stage 19, a condenser-evaporator 20, a condenser of the second stage 21, thermostatic valves of the first 22 and second 23; high pressure fan 24; streams: 1.0 - feed the initial oilseeds to the prepress; 1.1 - drainage of oil from the prepress; 1.2 - removal of squeezed seeds from prepress 1 for cooling to the air cooler 2; 1.3 - removal of chilled seeds from the cooler 2 in the roller machine 3; 1.4 - removal of unmilled seeds into the separating machine 5 for regrinding; 1.5 - removal of crushed seeds into the conditioning machine 6; 1.7 - drainage pulp of crushed seeds in the form of a "petal" in the extractor 7; 1.8 - discharge of meal from the extractor 6 into the screw extruder 11; 1.9 - removal of pellets from the extruder 11 to the air cooler 12; 1.10 - discharge of chilled pellets; 5.0 - refrigerant recirculation in a closed cycle of the first stage of a high-temperature two-stage vapor compression heat pump; 6.0 - refrigerant recirculation in a closed cycle of the second stage of a high-temperature two-stage vapor compression heat pump; 2.0 - supply of chilled air from the evaporator 19 to the air coolers 2 and 12; 2.1 - exhaust air after air coolers in the cyclone 13; 2.2 - supply of purified air from suspended particles from the cyclone 14 to the evaporator of the first stage 19; 2.3 - removal of particles from cyclone 13; 3.0 - supply of superheated steam from the condenser of the second stage 21 to the heating jacket of the extruder 11; 3.1 - supply of high-potential steam from the heating jacket of the extruder 11 into the heating chamber of the vacuum evaporator 7; 3.2 - supply of low-grade steam from the heating chamber of the vacuum evaporator 7 to the heat exchanger-recuperator 8; 3.3 - exhaust steam from the heat exchanger-recuperator 8 to the condenser of the second stage 21; 4.0 - removal of saturated vapors of hexane from extractor 6 into a vacuum evaporation apparatus 8; 4.1 - supply of hexane vapor from the vacuum evaporator to the heat exchanger-recuperator 9; 4.2 - removal of the condensed vapors of hexane from the heat exchanger-recuperator first to the condensate collector of hexane 10, and then to the extractor 7; 4.3 - evacuation line of the evaporator 7.

The scheme works as follows.

The initial oilseeds are fed downstream 1.0 to prepress 1, where oilcake and oil are obtained from the seeds. The oil is diverted to storage by stream 1.1, and the cake by stream 1.2 is sent to an air cooler 2, in which the cake is cooled in a gravitationally moving layer to a temperature of 17 ... 20 ° C and by stream 1.3 is sent to a roller mill 3. The crushed cake to fraction 1 ... 4 mm downstream 1.4 are sent to the separating machine 4. In the separating machine, the fraction of the desired size is selected, and larger particles along the 1.5 flow are sent to regrinding in the roller mill 3. The crushed cake 1.6 is directed to the conditioning machine 5, where the fraction is obtained in the form of a petal or grain, which is fed downstream 1.7 to the loading column of the vertical screw extractor 7. The material to be extracted is picked up by the turns of the screw and first moves down the loading column, then through the horizontal transfer screw they enter the extraction column, where they are lifted to the upper part by the screw .

At the same time, liquid hexane is fed into the extractor through stream 4.2, which moves in countercurrent with the extracted material. Due to the difference in concentration, the oil from the extracted material passes into hexane, forming a solution of the oil in the solvent - miscella.

The meal obtained in the extractor is fed by a stream 1.8 to a screw extruder with a heating jacket 11. During the extrusion process, the meal is processed at a temperature of 195 ... 205 ° C, which contributes to the release of lignin from it, which makes it possible to obtain high-quality granules with high strength, and saturated hexane oil, direct stream 4.0 in a vacuum evaporator 8.

In a vacuum evaporation apparatus 7 with a film flow of miscella, for example, with an ascending film, the high-potential steam supplied through stream 5.0 to the heating chamber of the vacuum evaporator causes intense boiling of the oil solution in the solvent under reduced pressure created by the vacuum line with a vacuum pump 9. At the same time, oil is extracted from saturated hexane and removed through the lower part of the vacuum evaporator through stream 1.2, and boiling hexane vapors are taken downstream 4.1 to heat exchanger-recuperator 8, where they are condensed at a temperature of 69 ... 71 ° C and then downstream 4.2 take hexane 10 to the condensate collector 10. Liquid hexane from the condensate collector 10 is pumped to the extractor 7 by a pump 18 to form a closed cycle.

To obtain superheated steam supplied to the heating jacket of the screw extruder 11 with the removal of high-potential steam in a vacuum evaporator 7 for evaporating oil from saturated hexane; by supplying low-grade steam from the heating chamber of the vacuum evaporator 7 to the heat exchanger-recuperator 8 to condense the hexane vapor; the preparation of chilled air for cooling the meal before grinding in a roller mill 3 and pellets after the extruder in air coolers 2 and 12, respectively, use a two-stage high-temperature vapor compression heat pump.

The first stage refrigerant, for example, R142b freon, is sucked up by the first stage compressor 17, is compressed to the condensation pressure and sent through a closed loop 5.0 to the condenser-evaporator 20. Due to compression compression in the first stage 17 compressor, the refrigerant is brought to the condensation temperature, for example, 47-50 ° C, and due to the regenerative heat transfer in the condenser-evaporator 19, it gives off heat to the boiling of the refrigerant of the second stage, which is used, for example, R113 freon. Then the refrigerant of the first stage is sent to the thermostatic valve 22, where it is throttled to a predetermined pressure. With this pressure, the refrigerant enters the evaporator of the first stage 19, in which it boils at a temperature of -9.2 ° C, which makes it possible to bring the air cooling temperature due to regenerative heat transfer to 14 ... 16 ° C

The refrigerant vapor of the second stage after the condenser-evaporator 19 is compressed by the compressor of the second stage 18 and condenses in the condenser of the second stage 21 at a temperature, for example 205 ... 210 ° C, which allows for the preparation of superheated steam with a temperature of 200 ... 205 ° C supplied to the heating jacket of the extruder 11. After the condenser of the second stage 21, the refrigerant of the second stage is throttled through the thermostatic valve of the second stage 23, brought to the boiling pressure, and 6.0 is fed to the condenser-evaporator 20 along the recirculation loop and boils, for example, at a temperature of 47.6 ° C, after which the thermodynamic cycle repeated.

High-potential steam with a temperature of 120 ... 130 ° C after the screw extruder is sent via stream 3.1 to the heating chamber of the evaporator 7, in which the temperature regime of extraction of cake petals is maintained at 90 ... 100 ° C due to regenerative heat transfer between miscella and high-potential steam. Low-grade steam after the vacuum evaporator is sent to stream 3.2 with a temperature of 40 ... 45 ° С, stream 3.2 is fed to heat exchanger-recuperator 8 to condense hexane vapor, and then it is returned via stream 3.3 to steam overheating to the second stage condenser with the formation of a recirculation loop.

Cooled air with a temperature of 17 ... 20 ° C is obtained in the evaporator of the first stage 19 due to recuperative heat exchange with boiling refrigerant and a blowing fan 15 for streams 2.0 are sent to air coolers 2 and 12 through a flow distributor 16 for cooling the cake before grinding in a roller mill 4 and pellet after the extruder 11, after which the exhaust air flows through streams 2.1 into the cyclone 13 for purification of suspended particles and stream 2.2 returns to the evaporator 19 to cool the air to form a closed cycle.

A method for the production of pellets from oilseed meal and a device for its implementation are implemented on an experimental production line with a productivity of 3 ... 5 t / h in the production conditions of Sogal-ECO LLC.

Energy-efficient modes of technological operations in the field of permissible properties were carried out using a two-stage steam compression heat pump with the following parameters:

The working fluid of the first stage (refrigerant) Freon R142b Evaporator Boiling Point first stage, ° C minus 9.2 The condensation temperature in the evaporator condenser ° C 47-50 Cooling capacity, kW 6.2 First stage compressor FVBS6 Compressor motor power first stage, kW 4.2 The working fluid of the second stage (refrigerant) Freon R113 Boiling point in a condenser-evaporator, ° С 47.6 Condenser temperature in the condenser second stage, ° C 205-210 Cooling capacity, kW eleven Second stage compressor Comprag RCI-11-270 Compressor motor power second stage, kW 10

A two-stage vapor compression heat pump provided the necessary performance of a second-stage tubular condenser with a working condensation temperature of 200 ... 210 ° С upon receipt of superheated steam with a temperature of 195 ... 205 ° С, which is necessary for efficient and balanced implementation of heat and mass transfer and thermal processes: extraction, evaporation, extrusion, regenerative heat transfer, cooling.

The quality indicators of feed pellets obtained from oilcake of various oilseeds (table) indicate the high efficiency of the proposed method both from the point of view of the stability of the process flow, the operation of which is ensured at a given level of quality of the obtained products, and from the point of view of saving energy costs per unit mass of feed pellets obtained.

Thus, the proposed method for the production of pellets from oilseed meal and a device for its implementation can create conditions for the implementation of energy-efficient technology in the continuous operation of the main and auxiliary equipment and reduce energy consumption for the line with a capacity of 5 t / h by 15 ... 20% from 25 ... 27 kWh up to 19 ... 20 kWh per 1 ton of granules produced.

Received with minimal energy costs feed pellets from oilcake of various oilseeds meet the requirements of the state standard [GOST 23513-79 Feed briquettes and pellets. Specifications].

The inventive method for the production of pellets from oilcake oilseeds and a device for its implementation allow:

- implement the proposed method as an energy-saving technology with maximum utilization and recovery of secondary energy carriers in closed thermodynamic cycles in material and heat flows;

- to ensure the preparation of coolants of different temperature potentials using a two-stage vapor compression heat pump;

- increase the reliability of operation of the equipment in the production of feed pellets from oilseed meal at a given level of quality;

- create conditions for non-waste production;

- minimize the emission of waste coolant into the surrounding atmosphere and increase the environmental safety of the proposed method.

Claims (2)

1. Method for the production of pellets from oilseed oil cake, which provides for the production of vegetable oil and oil cake with the removal of oil for cleaning, grinding oil cake to a size of 2-4 mm, extraction of the petals of the oil cake obtained at a temperature of 60 ... 100 ° C and a residual pressure of 70 ... 100 kPa distillation of miscella and distillation of the solvent from the meal with continuous removal of the formed vapors, characterized in that hexane is used as an organic solvent for the extraction of vegetable oil, the temperature regime for the extraction of the petals of the cake is carried out by heat exchange between the miscella and high-potential steam with a temperature of 120 ... 130 ° WITH; vapors of boiling hexane are condensed at a temperature of 69 ... 71 ° С due to regenerative heat exchange with low-grade steam with a temperature of 40 ... 45 ° С; the meal obtained after extraction is extruded at a temperature of 180 ... 190 ° C, the temperature regime of which is ensured by recuperative heat exchange with superheated steam at a temperature of 190 ... 200 ° C, and the cake before grinding and pellets obtained after extrusion are cooled with cooled air to a temperature of 16 ... 18 ° C and 20 ... 22 ° C. 2. A device for the production of pellets from oilseed oil cake, including forpress; roller mill; separation machine; flatting machine; vertical extractor; vacuum evaporator with a heating chamber and nozzles for supplying steam and exhaust steam; heat exchanger-recuperator with inlet and outlet pipes; collection of condensed vapors of hexane; characterized in that it further includes a screw extruder with a heating jacket and nozzles for supplying superheated steam and removal of high-potential steam; air coolers with nozzles for supplying chilled and exhaust air installed in front of the grinder and after the screw extruder; cyclone for air purification from suspended particles; forcing and exhaust fans for air; high pressure fan; a high-temperature two-stage vapor compression heat pump, including first and second stage compressors, a first stage evaporator with an inlet pipe for supplying exhaust air and an outlet pipe for discharging cooled air; a second stage condenser with a pipe for supplying exhaust steam and a pipe for supplying superheated steam to the inlet pipe of the heating jacket of the extruder; condenser-evaporator, which for the first stage is a condenser, and for the second stage an evaporator, thermostatic valves of the first and second stage; in this case, the outlet pipe for exhausting the cooled air of the first stage evaporator is connected to the inlet pipes of the air coolers through the blower fan, and the outlet pipes of the air coolers are connected in series with a cyclone for cleaning air from suspended particles, an exhaust fan and with an inlet pipe for supplying exhaust air to the evaporator of the first stage with the formation closed loop; the second stage condenser superheated steam supply pipe is connected in series with a high-pressure fan, the inlet pipe of the heating jacket of the extruder, the high-pressure steam outlet pipe of which is connected to the inlet of the heating chamber of the evaporator, and the output pipe of the heating chamber of the evaporator is connected to the inlet of the low-potential steam of the regenerative heat exchanger; the outlet pipe of the recuperative heat exchanger is connected to the pipe for supplying the spent steam of the condenser of the second stage with the formation of a closed loop.

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