RU2773436C1 - Method for controlling the vegetable oil production line - Google Patents

Abstract

FIELD: fat-and-oil industry.

SUBSTANCE: invention relates to the automation of engineering processes and can be used in the fat-and-oil industry, in particular in controlling the vegetable oil production line. A method for controlling the vegetable oil production line, which provides for drying seeds with a drying agent with a temperature of 89-90°C to a humidity of 8%; grinding of dried seeds in a roller machine up to 1 mm, additional grinding of a large fraction after a separating machine; roasting of the crushed fraction to a humidity of 1.5-3.0% in a vat roaster with a stirrer and steam heating of the frying surface; mechanical extraction of the formed fiber in the pre-press with the removal of the pre-press cake for extraction; filtration of the resulting oil in a drum filter press under a pressure of 0.2-0.5 MPa; freezing of wax substances from filtered oil in the expositor at a temperature of 8-12°C to 0.03% of the oil mass; removal of oil from the expositor as finished products; cleaning of spent drying agent with a temperature of 60-70°C and moisture content of up to 0.030 kg/kg, first in a cyclone, and then in a fine filter to a dust fraction content of no more than 30 mg/m; the discharge of the spent purified drying agent first into the air receiver, then into an intermediate heat exchanger between the flows of the spent drying agent and the one fed into the dryer, and then for cooling to the dew point temperature and dehumidification to a moisture content of 0.005-0.009 kg/kg in the cold receiver of a steam-ejector heat pump, including an ejector, an evaporator, a recirculation pump, a temperature-regulating valve, steam generator with electric heating elements and a safety valve, a condensate collector; supply of working steam produced in the steam generator to the ejector; creation of vacuum by ejected vapors in an evaporator with a boiling point of 5-7°C water used as a refrigerant; supply of a mixture of working and ejected vapors to the nozzle of the ejector, in the diffuser of which the kinetic energy of the mixture flow is converted into thermal energy of high-potential steam with a temperature of 210-220°C, supplied for heating the frying surface of the vat roaster; the supply of low-potential steam after the roaster through the steam receiver to the heat exchanger-recuperator, in which, due to regenerative heat exchange, the drying agent is heated with subsequent supply to the dryer in a closed cycle mode; the removal of part of the formed condensate from the heat exchanger-recuperator first through a temperature-regulating valve to replenish the loss of water in the evaporator, and the supply of the other part together with the formed condensate in the cold receiver, first into the condensate collector, and then to replenish the water level in the steam generator; the supply of a refrigerant with a temperature of 5-7°C to the cooling jacket of the expositor for cooling the oil and returning water to the cold receiver in a closed cycle mode; and providing microprocessor control of technological parameters with continuous measurement of temperature, moisture content and consumption of oilseeds fed into the dryer; temperature, flow and moisture content of the drying agent before and after the dryer; flow, temperature and humidity of crushed seeds after the separating machine; the flow rate and temperature of high-potential steam for heating the frying surface of the vat roaster; consumption and temperature of low-potential steam supplied through the receiver to the heat exchanger-recuperator; consumption of fiber obtained as a result of frying; consumption of vegetable oil after the pre-press; consumption of filtered oil after the drum filter press, oil temperature in the expositor; consumption of oil purified from wax substances after the expositor; pressure and water level in the steam generator; dilution, temperature and water level in the evaporator; condensation temperature of water vapor from the spent drying agent in the cold receiver; the flow rate and temperature of the refrigerant supplied to the cooler and to the cooling jacket of the expositor; at the same time, according to the current values of the flow rate, temperature and humidity of the initial seeds, the microprocessor sets the temperature and flow rate of the drying agent supplied to the dryer; sets the rotation frequency of the rollers and the distance between them in the roller machine depending on the humidity of the dried seeds; according to the magnitude of the mismatch of the current seed humidity at the outlet of the vat roaster with a given value, it sets the flow rate and temperature of high-potential steam by affecting the flow rate of the working steam by changing the steam output of the steam generator; stabilizes the oil output from the pre-press depending on the oil content of the seeds by affecting the power of the pre-press screw drive; controls the pressure of oil supplied to the drum filter press, the rotation frequency the drum of the drum filter press and the consumption of compressed air for the oil filtration process; according to the flow rate of the filtered oil, the refrigerant flow rate is set in the expositor cooling jacket; according to the measured values of the humidity content of the drying agent before and after drying and its flow rate at the outlet of the dryer, it determines the amount of water vapor in the spent drying agent, according to which it sets the boiling point of the refrigerant in the evaporator by affecting the ejection coefficient of the steam-ejector heat pump by changing the ratio of the flow rates of the working steam supplied to the nozzle of the ejector and the ejected refrigerant vapor from the evaporator with continuous monitoring of the humidity content of the drying agent after the cold receiver; the change in the steam capacity of the steam generator is carried out by affecting the power of electric heating elements, and when the water level in the steam generator decreases below the set value, it supplies water from the condensate collector to the steam generator, and when the steam pressure in the steam generator reaches the upper limit value, it relieves the steam pressure through a safety valve.

EFFECT: invention makes it possible to increase the accuracy and reliability of the control of the vegetable oil production line, which ensures higher quality of the obtained vegetable oil, to increase productivity with the rational use of energy costs.

1 cl, 1 dwg, 2 tbl, 1 ex

Description

The invention relates to the automation of technological processes and can be used in the oil and fat industry, in particular when controlling a line for the production of vegetable oil.

A known line for the production of vegetable oil (Pat. 2595152 C1, C11B 1/00), including a dryer for oil seeds; cyclone for cleaning exhaust air after drying; roller machine; separating machine; fryer; forpress; filter press; expositor; heat exchanger-recuperator; a vapor compression heat pump containing a compressor, a condenser, a thermostatic expansion valve and two evaporator sections, one of which is used to freeze wax substances from vegetable oil in the exposure chamber, and the other to condense moisture from the exhaust air. In the known line, a method for the production of vegetable oil using a vapor compression heat pump is implemented, while the drying process is carried out with conditioned air; the exhaust air after drying is subjected to purification from suspended particles in a cyclone, followed by cooling and dehumidification in the evaporator section of the heat pump and supply to the dryer to form a closed cycle; superheated steam after the heat pump condenser is fed for roasting, while part of the exhaust superheated steam in the amount of moisture evaporated from the product is fed into the heat exchanger-recuperator for air heating; and the second part of the spent superheated steam is diverted to the heat pump condenser, where it is superheated and re-fed for roasting in the closed cycle mode.

However, the known line has the following disadvantages:

- the presence of a mechanical drive reduces the reliability of the vapor-compression heat pump installation and, as a result, can lead to a decrease in line performance due to possible shutdowns for maintenance and repair;

- with a large temperature difference in the evaporator and condenser, the thermodynamic efficiency of the vapor-compression heat pump cycle is significantly reduced, which leads to an increase in energy costs during compression compression of the refrigerant vapor;

- to implement the reverse thermodynamic cycle in vapor-compression heat pumps, it is necessary to use expensive ozone-friendly refrigerants, which will affect the cost of the resulting vegetable oil;

- there is no control system for technological parameters at all stages of vegetable oil production;

- it is advisable to use a vapor compression heat pump in a decentralized energy supply system, when there are no sources of high-potential thermal energy (boiler units, gas turbine plants, etc.). The traditional orientation of oil and fat industry enterprises towards district heating casts doubt on the use of vapor-compression heat pumps in vegetable oil production technology, at least in the near future, including taking into account their high cost.

The closest in technical essence and the achieved effect is a method of controlling the line of production of vegetable oil (Pat. 2619278 C1, C11B 1/06), including: dryer; roller machine; separating machine; fryer; forpress; drum filter press; expositor with a shirt; cyclone; heat exchanger-recuperator; fans; steam generator; condensate collector; a steam ejector refrigeration machine operating in a heat pump mode, containing a condenser, a cold receiver, an ejector, an evaporator, pumps, and a thermostatic valve.

In this method, the working steam from the steam generator is fed into the ejector, the ejected vapors from the evaporator create a vacuum in it with a boiling point of water of 5-7°C, used as a refrigerant; a mixture of working and ejected vapors is fed into the ejector nozzle, in the diffuser of which the kinetic energy of the mixture flow is converted into thermal energy of high-potential steam supplied to the fryer; low-grade steam after the fryer is removed to the heat exchanger-recuperator, where, due to recuperative heat exchange, the temperature of the drying agent is brought to 85-90°C; spent drying agent with a temperature of 60-70°C is subjected to cleaning in a cyclone and fed into a cold receiver, where it is cooled to the dew point temperature and dried with subsequent supply to the heat exchanger-recuperator; part of the formed condensate from the heat exchanger-recuperator is first removed through a thermostatic valve to replenish the loss of water in the evaporator, and the other part, together with the formed condensate in the cold receiver, is first removed to the condensate collector, and then to replenish the water level in the steam generator; the extraction of wax substances from the oil is carried out in the process of its recuperative cooling in the expositor with water cooled in the cold receiver, with the return of water to the cold receiver in the closed cycle mode.

The disadvantage of this method is that it does not provide control of the line at all stages of the production of vegetable oil, as well as a steam jet heat pump in the preparation of energy carriers of different temperature potential. The lack of current information about the processes of drying, roasting, pressing, cooling, obtained from sensors, does not allow creating a system for the operational control of energy flow parameters in the range of rational values that ensure savings in heat and power costs.

The known method does not provide accuracy and reliability of control, does not create prospects for improving the quality of vegetable oil, which is associated with the stabilization of the temperature regimes of thermal and heat and mass transfer processes under conditions of random disturbances both from a possible change in the composition of vegetable oil due to its quality, and from possible technological failures in the operation of the main and auxiliary equipment. The method does not take into account the influence of the main parameters of the technological process on the yield of vegetable oil when identifying the most effective modes that provide an increase in the productivity of the process flow on an industrial scale with minimal energy costs per unit mass of the resulting oil.

The objective of the invention is to increase the accuracy and reliability of control of the vegetable oil production line, which improves the quality of the resulting vegetable oil, increases productivity with the rational use of energy costs.

The set technical task of the invention is achieved by the method of controlling a vegetable oil production line, which involves drying the seeds with a drying agent at a temperature of 89-90°C to a moisture content of 8%; grinding of dried seeds in a roller mill up to 1 mm, regrinding of a large fraction after a separating machine; roasting the crushed fraction to a moisture content of 1.5-3.0% in a vat brazier with a stirrer and steam heating of the frying surface; mechanical extraction of the resulting pulp in the forpress with the removal of the forpress cake for extraction; filtering the resulting oil in a drum filter press under a pressure of 0.2-0.5 MPa; freezing out wax substances from the filtered oil in an expositor at a temperature of 8-12°C to 0.03% by weight of the oil; withdrawal of oil from the exhibitor as a finished product; purification of the spent drying agent with a temperature of 60-70°C and a moisture content of up to 0.030 kg/kg, first in a cyclone, and then in a fine filter to a pulverized fraction content of not more than 30 mg/m ³ ; removal of the spent purified drying agent first to the air receiver, then to an intermediate heat exchanger between the flows of the spent drying agent and supplied to the dryer, and then for cooling to the dew point temperature and drying to a moisture content of 0.005-0.009 kg/kg in the cold receiver of the steam jet heat pump , including an ejector, an evaporator, a recirculation pump, a thermostatic valve, a steam generator with electric heating elements and a safety valve, a condensate collector; supply of working steam obtained in the steam generator to the ejector; creation by ejected vapors of rarefaction in the evaporator with a boiling point of water of 5-7°C, used as a refrigerant; supplying a mixture of working and ejected vapors to the ejector nozzle, in the diffuser of which the kinetic energy of the mixture flow is converted into thermal energy of high-potential steam with a temperature of 210-220 ° C, supplied to heat the frying surface of the vat brazier; supply of low-grade steam after the fryer through the steam receiver to the heat exchanger-recuperator, in which the drying agent is heated due to recuperative heat exchange with subsequent supply to the dryer in a closed cycle mode; removal of part of the formed condensate from the heat exchanger-recuperator, first through a thermostatic valve to replenish the loss of water in the evaporator, and the supply of the other part, together with the formed condensate in the cold receiver, first to the condensate collector, and then to replenish the water level in the steam generator; supply of refrigerant from temperatures of 5-7°C to the cooling jacket of the expositor for oil cooling and return of the refrigerant to the cold receiver in the closed cycle mode; the method provides for microprocessor control of technological parameters with continuous measurement of temperature, moisture content and consumption of oilseeds supplied to the dryer; temperature, consumption and moisture content of the drying agent before and after the dryer; consumption, temperature and humidity of crushed seeds after the separating machine; consumption and temperature of high-potential steam for heating the frying surface of a vat brazier; flow rate and temperature of low-grade steam supplied through the steam receiver to the heat exchanger-recuperator; the consumption of pulp obtained as a result of roasting; consumption of vegetable oil after forpress; filtered oil consumption after the drum filter press, oil temperature in the expositor; consumption of wax-free oil after the expositor; pressure and water level in the steam generator; vacuum, temperature and water level in the evaporator; temperature of condensation of water vapor from the spent drying agent in the cold receiver; flow rate and temperature of the refrigerant supplied to the cold receiver and to the cooling jacket of the expositor; at the same time, according to the current values of consumption, temperature and humidity of the initial seeds, the microprocessor sets the temperature and consumption of the drying agent supplied to the dryer; sets the frequency of rotation of the rollers and the distance between them in the roller machine, depending on the moisture content of the dried seeds; by the magnitude of the discrepancy between the current moisture content of the seeds at the outlet of the vat brazier with a given value, it sets the flow rate and temperature of the high-potential steam by influencing the flow rate of the working steam by changing the steam generator steam output; stabilizes the output of oil from the forpress, depending on the oil content of the seeds by affecting the drive power of the forpress auger; controls the pressure of the oil supplied to the drum filter press, the rotational speed of the drum filter press drum and the consumption of compressed air for the oil filtration process; according to the flow rate of filtered oil, sets the flow rate of the refrigerant in the cooling jacket of the expositor; according to the measured values of the moisture content of the drying agent before and after drying and its flow rate at the outlet of the dryer, determines the amount of water vapor in the spent drying agent, according to which it sets the boiling point of the refrigerant in the evaporator by affecting the ejection coefficient of the steam jet heat pump by changing the ratio of the flow rates of the working steam supplied to ejector nozzle, and ejected refrigerant vapors from the evaporator with continuous monitoring of the moisture content of the drying agent after the cold receiver; the change in the steam generator steam capacity is carried out by affecting the power of the electric heating elements, and when the water level in the steam generator drops below the set value, it supplies water from the condensate collector to the steam generator, and when the steam pressure in the steam generator reaches the upper limit value, it releases the steam pressure through the safety valve.

The drawing shows a diagram that implements the proposed method for controlling a vegetable oil production line.

The scheme contains a dryer 1, a roller machine 2, a separating machine 3, a vat brazier 4 with a stirrer and steam heating of the frying surface, a forpress 5; storage tank for oil 6; oil pump 7; drum filter press 8; expositor 9; cyclone 10; fine filters 11; heat exchanger-recuperator 12; steam ejector heat pump (PETH), including ejector 13, evaporator 14, cold receiver 15, recirculation pump 16, expansion valve 17, steam generator 18 with electric heating elements 19 and safety valve 20, condensate collector 21, pump 22, dampers 23, 24, 25; fans 26 and 27 with adjustable drive, air receiver 28; steam receiver 29; intermediate heat exchanger 30, microprocessor 31; lines of material and heat flows: 1.1 - supply of oilseeds to the dryer; 1.2 - removal of dried oilseeds from the dryer for grinding into a roller machine; 1.3 - removal of crushed oilseeds from the roller machine to the separating machine; 1.4 - removal of the separating machine from the sieve for regrinding; 1.5 - removal of crushed seeds to the roaster; 1.6 - removal of the pulp from the fryer to the forpress; 1.7 - draining oil from the forpress into the storage tank first, and then into the drum filter; 1.8 - withdrawal of forpress cake; 1.9 - sediment removal from the drum filter; 1.10 - removal of the filtered oil from the drum filter to the expositor; 1.11 - removal of wax substances from the expositor; 1.12 - removal of purified oil from wax substances; 2.0 - removal of high-potential steam from the steam generator to the ejector; 2.1 - ejected steam from the evaporator; 2.2 - a mixture of high-potential and ejected steam for heating the frying surface of a vat brazier; 2.3 - supply of low-grade steam from the brazier to the recuperative heat exchanger; 2.4 - recirculation of the refrigerant through the cold receiver; 2.5 - condensate drain from the cold receiver to the condensate collector; 2.6 - recirculation of the coolant through the cooling jacket of the expositor; 3.0 - supply of dried drying agent from the cold receiver to the recuperative heat exchanger; 3.1 feeding the heated drying agent into the dryer; 3.2 - removal of the spent drying agent for cleaning, first into a cyclone, and then into a fine filter; 3.3 - supply of purified air to the cold receiver; 4.0 - compressed air supply to the drum filter; 5.0 - removal of solid particles from the cyclone; sensors: TE - temperature, FE - flow, ME - humidity and moisture content, HE - level, PE - pressure, nE - speed, lE - distance between the rolls of the roller machine.

The technological cycle of processing oilseeds into vegetable oil according to the claimed method is carried out as follows.

Pre-washed oilseeds on line 1.1 served in the dryer 1; dried seeds are sent along line 1.2 to the roller machine 2, after which, along line 1.3, the crushed seeds are fed into the separating machine 3, where the descent along line 1.4 is sent for regrinding. The crushed seeds are sent along line 1.5 for roasting to a vat brazier 4 with a stirrer. The pulp obtained as a result of roasting is fed through line 1.6 to forpress 5, oil through line 1.7 from forpress 5 is first sent to storage tank 6, and then under pressure for filtration into drum filter press 8 with oil pump 7. Forpress cake is taken to extraction, the precipitate is removed through line 1.9 for further processing, and the filtered oil is sent through line 1.10 from the drum filter press 8 to the expositor 9 with a cooling jacket for freezing out wax substances, which are removed through line 7.77, and the purified oil is removed through line 7.72.

The process of drying oilseeds in the dryer 1 is carried out with a drying agent with a temperature of 89-90°C, which is heated in a heat exchanger-recuperator 12. The spent drying agent with a temperature of 60-70°C is subjected to cleaning in a cyclone and a fine filter to a pulverized fraction content of not more than 30 mg / m ³ and through line 3.3 is first fed into the air receiver 27, then by a fan 26 into the intermediate heat exchanger 28 and then into the cold receiver 15, where it is cooled to the dew point temperature and dried to a moisture content of 0.005-0.009 kg / kg s subsequent supply to the heat exchanger-recuperator 12.

In the intermediate heat exchanger 30, the drying agent supplied to the heat exchanger-recuperator 12 via line 3.0 is preheated and the spent drying agent is cooled, which is sent for moisture condensation to the cold receiver 16 via line 3.3. This will reduce energy costs by reducing the refrigerant consumption in the recirculation circuit when moisture is condensed from the spent drying agent, providing an increase in its moisture absorption capacity.

The working steam obtained in the steam generator 18 is fed through line 2.0 to the ejector 13; ejected vapors from the evaporator 14 through line 2.1 create a vacuum in it with a boiling point of water of 5-7°C. A mixture of working and ejected vapors is fed into the ejector nozzle, in the diffuser of which the kinetic energy of the mixture flow is converted into thermal energy of high-potential steam supplied through line 2.2 to heat the frying surface of the vat brazier 4 with agitator. Low-grade steam after the vat fryer is removed via line 2.3 through the steam receiver 29 to the heat exchanger-recuperator 12, where, due to recuperative heat exchange, it heats the drying agent to a temperature of 85-90 ° C, from which it is fed into the dryer.

Part of the condensate formed from the heat exchanger 12 is first removed through line 2.4 through the expansion valve 17 to replenish the loss of water in the evaporator 14, and the other part, together with the condensate formed in the cold receiver 15, is first removed through line 2.4 to the condensate collector 21, and then pump 22 to replenishment of the water level in the steam generator 18 with the formation of a closed cycle.

The refrigerant, which is used as water, circulates through line 2.5 with the help of a recirculation pump 16 through the cold receiver 15 and the cooling jacket of the display 9. The process of cooling the oil in the exhibitor 9 with the removal of wax substances through the line 7.77 is carried out by the coolant supplied to the cooling jacket of the exhibitor from the cold receiver 15 through line 2.5 by pump 16 with refrigerant return through line 2.6 to the cold receiver in closed-loop mode. The purified oil is withdrawn from the expositor along line 1.12.

Information about the course of technological operations in the vegetable oil production line is transmitted with the help of sensors to the microprocessor 31, which, according to the program-logical algorithm embedded in it, performs operational control of technological parameters by means of actuators, taking into account the restrictions imposed on them, due to both economic feasibility and maximum high quality biodiesel output.

The microprocess 31 continuously measures the temperature, moisture content and flow rate of the washed oilseeds in line 1.1 fed into the dryer; temperature, consumption and moisture content of the drying agent before and after the dryer, respectively, in lines 3.1 and 3.3; the consumption of seeds crushed to 1 mm in line 1.3, as well as their temperature and humidity after the separating machine in line 1.5; consumption and temperature of high-potential steam supplied to heat the frying surface of the vat brazier in line 2.2; flow rate and temperature of low-potential steam supplied to the heat exchanger-recuperator in line 2.3; consumption and oil content of roasted seeds (pulp) in line 1.6; vegetable oil consumption after forpress in line 7.7; consumption of forpress cake in the line 1.8; filtered oil consumption in the line 1.10; oil temperature in the expositor; consumption of wax-free oil after the expositor in line 7.72; pressure and water level in the steam generator; vacuum, temperature and water level in the evaporator; temperature of the refrigerant in the cold receiver; flow rate and temperature of chilled water supplied to the cold receiver and to the cooling jacket of the expositor through line 2.5.

According to the current values of consumption, temperature and humidity of the washed seeds, the microprocessor:

- sets the flow rate and temperature of the drying agent supplied to the dryer through line 3.1 using a fan 26 with an adjustable drive and the flow rate of low-grade steam from the fryer through the receiver 29 to the recuperative heat exchanger 12 in line 2.3 by changing the position of the damper using the actuator 25;

- depending on the moisture content of the dried seeds, sets the frequency of rotation of the rollers and the distance between them in the roller machine 2;

- according to the moisture consumption and the temperature of the crushed seeds, it sets the consumption of high-potential steam for heating the frying surface of the vat brazier and the rotation frequency of the agitator;

- according to the magnitude of the mismatch of the current seed moisture at the outlet of the roaster with a set value of 1.5-3.0%, it affects the flow rate and temperature of high-potential steam;

- depending on the oil content of the seeds (preliminarily determined in the laboratory) and the consumption of roasted seeds, it sets the drive power of the forepress screw and controls the output of oil in the range of 18-42% (depending on the oilseed) discharged from the forepress into the drum filter press, and when the oil output deviates from the set value, the pressing mode is corrected by influencing the power of the forepress screw drive;

- sets the specified oil pressure of 0.2-0.5 MPa supplied to the drum filter press by the oil pump 7, the rotational speed of the filter drum and the compressed air consumption for the filtration process;

- according to the consumption of filtered oil, it sets the flow rate of the refrigerant in the cooling jacket of the expositor, in which the oil is cooled to a temperature of 8-12°C with the removal of wax substances to 0.03% of the mass of the oil.

According to the measured values of the moisture content of the drying agent before and after drying and its consumption at the outlet of the dryer, the microprocessor determines the amount of water vapor supplied to the cold receiver 15 with the spent drying agent according to the formula:

U \ _u003d (x out - x _in ) ρ _sv V

where x _in , x _out - moisture content of the drying agent at the inlet and outlet of the dryer, kg/kg; ρ _St - the density of the absolutely dry part of the drying agent, kg/m ³ ; V - volumetric flow rate of the drying agent at the inlet to the dryer, m ³ /h.

Depending on the amount of water vapor in the spent drying agent, the microprocessor sets the ejection coefficient of the steam ejector heat pump by influencing the ratio of the flow rates of the working steam supplied to the ejector nozzle through line 2.0 and ejected from the evaporator through line 2.7, by changing the flow rate of working steam by influencing the steam generator steam output; the change in the steam capacity of the steam generator 18 is carried out by affecting the power of the electric heating elements 19, and when the water level in the steam generator drops below the set value, it supplies water from the condensate collector 21 to the steam generator through line 2.4, and when the steam pressure in the steam generator reaches the upper limit value, it releases the steam pressure through safety valve 20.

An example of the implementation of the method.

The method for controlling the vegetable oil production line is implemented on an experimental line with a capacity of 300 l/h for the original oil under the production conditions of Sogal-ECO LLC.

Energy-efficient modes of technological processes in the range of acceptable properties were carried out using a steam jet heat pump with the following parameters:

Cooling capacity, kW 20-25 Boiling temperature: in the evaporator, ° С 5-7 in the steam generator, ° С 110-115 High-potential steam temperature, °С 200-220 Ejection coefficient 4-6 Heat exchange surface area cold receiver, m ² eight Heat exchange surface area heat exchanger-recuperator, m ² 9 refrigerant water

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

High-potential steam was obtained in an electric steam generator "Ural-Power", which is capable of producing saturated and superheated steam up to 400°C and pressure up to 140 kgf/cm ² .

In the recirculation circuit of the steam ejector heat pump, a steam-steam ejector (thermocompressor) of the PKS type was used, which ensures the return of working steam to the system and its multiple use with the required parameters. The scale of energy and resource saving when using PKS is significant, since it made it possible to completely return to the system low-grade steam, which is usually discharged into the atmosphere, and to avoid losses associated with throttling and regulation of steam flows. The use of PCS reduced to a minimum technological emissions into the atmosphere and completely avoided environmental pollution from the discharge of waste coolants.

The rational use of thermal and electrical energy in the cold and heat supply system using a steam jet heat pump was considered from the point of view of reducing the cost of the resulting target and intermediate products. The main principal decision to reduce energy consumption in the proposed method is the optimal choice of the current values of the temperatures of the working steam and cold water. Deviation from these values will inevitably lead to an increase in energy consumption: a decrease in the boiling point of the refrigerant in the evaporator by 1°C will lead to the need to increase the flow of working steam into the ejector, and, consequently, to an excess energy consumption by 5-7%, and an increase in the condensation temperature by 1°C. C will lead to an increase in energy consumption by 7.0-10.0% [Thermal and structural calculations of refrigeration machines / Ε. M. Bambushek, Η. N. Bukharin, E. D. Gerasimov and others; Under the general, ed. I.A. Sakuna. - L .: Mashinostroenie, Leningrad. department, 1987. - 423 p.].

The following is the technical specification of the steam jet heat pump used in vegetable oil production line:

In table. Table 1 shows the limits of regulation by technological parameters of the line for the production of vegetable oil from rapeseed, flax and soybeans. The quality indicators of vegetable refined oil obtained by the proposed method, fully corresponds to the standard values (table. 2).

Thus, the proposed method for controlling a vegetable oil production line makes it possible to ensure the accuracy and reliability of control by reducing the spread of adjustable parameters, to ensure their variation in a given range, which is a significant reserve for intensifying thermal processes while reducing specific energy consumption and increasing the environmental safety of the environment.

Thus, the proposed method for controlling a vegetable oil production line makes it possible to ensure the accuracy and reliability of control by reducing the spread of adjustable parameters, to ensure their variation in a given range, which is a significant reserve for intensifying thermal processes while reducing specific energy consumption and increasing the environmental safety of the environment.

The use of operational information from the control object to control the temperature regimes of moisture condensation from moist air in the PETN cold receiver, its heating in a recuperative heat exchanger within the specified values creates optimal conditions for drying seeds with a drying agent with a high moisture-absorbing capacity. The generation of high-potential energy in the heat pump ejector creates the conditions for highly efficient production of alternative energy sources of different temperature potentials, which makes it possible to ensure high quality vegetable oil in the field of standard technological properties.

Claims (1)

A method for controlling a vegetable oil production line, involving drying seeds with a drying agent at a temperature of 89-90°C to a moisture content of 8%; grinding of dried seeds in a roller mill up to 1 mm, regrinding of a large fraction after a separating machine; roasting the crushed fraction to a moisture content of 1.5-3.0% in a vat brazier with a stirrer and steam heating of the frying surface; mechanical extraction of the resulting pulp in the forpress with the withdrawal of the forpress cake for extraction; filtering the obtained oil in a drum filter press under a pressure of 0.2-0.5 MPa; freezing wax substances from the filtered oil in an expositor at a temperature of 8-12°C to 0.03% by weight of the oil; withdrawal of oil from the exhibitor as a finished product; purification of the spent drying agent with a temperature of 60-70°C and a moisture content of up to 0.030 kg/kg, first in a cyclone, and then in a fine filter to a pulverized fraction content of not more than 30 mg/m; removal of the spent purified drying agent first to the air receiver, then to the intermediate heat exchanger between the flows of the spent drying agent and supplied to the dryer and then for cooling to the dew point temperature and drying to a moisture content of 0.005-0.009 kg/kg in the cold receiver of the steam jet heat pump, including an ejector, an evaporator, a recirculation pump, a thermostatic valve, a steam generator with electric heating elements and a safety valve, a condensate collector; supply of working steam obtained in the steam generator to the ejector; creation by ejected vapors of rarefaction in the evaporator with a boiling point of water of 5-7°C, used as a refrigerant; supplying a mixture of working and ejected vapors to the ejector nozzle, in the diffuser of which the kinetic energy of the mixture flow is converted into thermal energy of high-potential steam with a temperature of 210-220 ° C, supplied to heat the frying surface of the vat brazier; supply of low-grade steam after the fryer through the steam receiver to the heat exchanger-recuperator, in which the drying agent is heated due to recuperative heat exchange with subsequent supply to the dryer in a closed cycle mode; removal of part of the formed condensate from the heat exchanger-recuperator, first through a thermostatic valve to replenish the loss of water in the evaporator, and the supply of the other part, together with the formed condensate in the cold receiver, first to the condensate collector, and then to replenish the water level in the steam generator; supply of refrigerant from temperatures of 5-7°C to the cooling jacket of the expositor for oil cooling and return of water to the cold receiver in the closed cycle mode; and providing for microprocessor control of technological parameters with continuous measurement of temperature, moisture content and consumption of oilseeds supplied to the dryer; temperature, consumption and moisture content of the drying agent before and after the dryer; consumption, temperature and humidity of crushed seeds after the separating machine; consumption and temperature of high-potential steam for heating the frying surface of a vat brazier; flow rate and temperature of low-grade steam supplied through the receiver to the heat exchanger-recuperator; the consumption of pulp obtained as a result of roasting; consumption of vegetable oil after forpress; filtered oil consumption after the drum filter press, oil temperature in the expositor; consumption of wax-free oil after the expositor; pressure and water level in the steam generator; vacuum, temperature and water level in the evaporator; temperature of condensation of water vapor from the spent drying agent in the cold receiver; flow rate and temperature of the refrigerant supplied to the cold receiver and to the cooling jacket of the expositor; at the same time, according to the current values of consumption, temperature and humidity of the initial seeds, the microprocessor sets the temperature and consumption of the drying agent supplied to the dryer; sets the frequency of rotation of the rollers and the distance between them in the roller machine, depending on the moisture content of the dried seeds; by the magnitude of the discrepancy between the current moisture content of the seeds at the outlet of the vat brazier with a given value, it sets the flow rate and temperature of the high-potential steam by influencing the flow rate of the working steam by changing the steam generator steam output; stabilizes the output of oil from the forpress, depending on the oil content of the seeds by affecting the drive power of the forpress auger; controls the pressure of the oil supplied to the drum filter press, the rotational speed of the drum filter press drum and the consumption of compressed air for the oil filtration process; according to the flow rate of filtered oil, sets the flow rate of the refrigerant in the cooling jacket of the expositor; according to the measured values of the moisture content of the drying agent before and after drying and its flow rate at the outlet of the dryer, determines the amount of water vapor in the spent drying agent, according to which it sets the boiling point of the refrigerant in the evaporator by affecting the ejection coefficient of the steam jet heat pump by changing the ratio of the flow rates of the working steam supplied to ejector nozzle, and ejected refrigerant vapor from the evaporator with continuous monitoring of the moisture content of the drying agent after the cold receiver; the change in the steam generator steam capacity is carried out by affecting the power of the electric heating elements, and when the water level in the steam generator drops below the set value, it supplies water from the condensate collector to the steam generator, and when the steam pressure in the steam generator reaches the upper limit value, it releases the steam pressure through the safety valve.

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