RU2425304C1 - Method to stabilise heat and moisture characteristics of cereal and oil plant seeds in process of drying and storage - Google Patents

Abstract

FIELD: agriculture. ^ SUBSTANCE: method of stabilisation includes control of drying processes in a shaft dryer and cooling of grain in process of its active ventilation in granaries of silo type with usage of a heat pump plant for preparation of a dried air in a working section of an evaporator and its division into two flows, one of which is supplied for active ventilation of grain into silos, and the other one - for drying of grain with subsequent recirculation in a closed contour with serial transfer into a condenser, a heater, a heat exchanger, a cyclone, a working section of an evaporator, which, alternately with a reserve section, switches from the condensation mode to the regeneration mode as the current value of heat transfer coefficient on the cooling surface of the evaporator reaches the limit permissible value, acting at the capacity of the compressor drive of the heat pump plant in process of dried air moisture and temperature control with correction by fresh air flow in the make-up line. The novelty is the fact that in order to stabilise heat and moisture characteristics of cereal and oil plants seeds, an oscillating mode of drying is used with alternation of grain heating and cooling processes in a multi-section dryer, which consists of heating and cooling sections; to realise the oscillating mode of drying, one part of cold air downstream the evaporator is sent to cool down grain in the cooling section of the multi-section dryer, and the other part - via a condenser of the heat pump plant and heaters - is sent to heat grain in each heating section of the dryer; the saturated steam is used for heating of air in the heater prior to its supply into heating sections of the dryer and for regeneration of the cooling element surface in a reserve section of the heat pump plant evaporator, besides, the saturated steam is produced in a steam generator with electric heating elements and a safety valve, at the same time the condensate of the saturated steam generated in the hearth and the reserve section of the heat pump plant evaporator is drained into a condensate collector, and then in the mode of the closed cycle it is again supplied into the steam generator to make up for water loss; dried grain prior to its laying for storage is treated with an antioxidant, besides, the used air after active ventilation of grain is supplied into the cyclone, in process of grain drying in the oscillating mode grain temperature and moisture are additionally measured in the heating sections, in the cooling sections - grain temperature, air flow, antioxidant consumption, saturated steam flow downstream the steam generator, steam pressure and condensate level in the steam generator are measured, besides, using grain temperature in the heating sections, the steam flow to heaters is established, and using grain moisture in the heating sections and grain temperature in the cooling sections, accordingly flow of hot and cold air is established by acting at the capacity of controlled drives of fans; ratio of dried grain flows and a flow of antioxidant supplied into a mixer, is maintained by variation of the antioxidant flow; the saturated steam pressure in the steam generator is used to establish the specified efficiency of the steam generator by acting at the capacity of electric heating elements, with reduction of condensate level in the steam generator below the specified value, the condensate is supplied from the condensate collector, and when the steam pressure in the steam generator achieves the upper limit value, the steam pressure is discharged via a safety valve. ^ EFFECT: method to stabilise heat and moisture characteristics of cereal and oil plants grain in process of its drying and storage makes it possible to increase quality of cereal and oil plants grain due to realisation of drying in oscillating modes by means of alternation of heating and cooling intervals, to increase time of grain storage as a result of its treatment prior to its laying for storage with an antioxidant in required quantities; to provide for synchronism in operation of a reserve and a working sections of the heat pump plant evaporator, and to increase quality of dried grain; to improve environmental safety of the process of grain heat and moisture characteristics stabilisation in process of drying and storage due to recirculation of used air after active ventilation of grain. ^ 1 dwg

Description

The invention relates to the automation of technological processes and can be used to automate the drying and storage of grain crops, in particular oilseeds, such as rapeseed, flax, amaranth, sunflower, etc.

The closest in technical essence and the achieved effect is a method of stabilizing the thermo-moisture characteristics of grain during its drying and storage [US Pat. Russian Federation No. 2303213, IPC ⁷ F26B 3/14, F26B 21/08, F26B 21/10, No. 2005133720/06; Stated on 02.11.2005; Publ. 07/20/2007; Bull. No. 20], including the control of drying processes in a shaft dryer and grain cooling when it is actively ventilated in silos of type silos using a heat pump unit for preparing dried air in the evaporator working section and dividing it into two streams, one of which is fed to the grain for active ventilation silos, and the other - for drying the grain, followed by recirculation in a closed loop with sequential supply to the condenser, air heater, heat exchanger, cyclone, the working section of the evaporator, which It switches from the condensing mode to the regeneration mode with the backup section when the current value of the heat transfer coefficient on the cooling surface of the evaporator reaches the maximum permissible value with the compressor pump drive power being affected by the heat pump unit while controlling the moisture content and temperature of the dried air with correction for fresh air flow in the make-up line.

However, the known method does not provide for drying oilseeds with a high content of fatty acids in oscillating modes by alternating heating and cooling intervals, ensuring the preservation of their biochemical composition, increasing shelf life for effective use in various industries.

In the known method, the defrosting (defrosting) of the evaporator section of the heat pump unit operating in the regeneration mode is carried out by air, i.e. air-vapor mixture taken from the atmosphere, first heated due to the heat of recovery of the dried grain when it is cooled, and then due to the heat of condensation of the refrigerant in the condenser of the heat pump unit. The melting process of the “snow coat” is much longer than the process of its formation, since the increase in the defrosting time of the evaporator section is significantly affected by diffusion resistance to the vapor flow from the side of non-condensing air [1. Modeling the process of moisture condensation from humid air on the cooling surface of the evaporator of a heat pump unit [Text] / A.A. Shevtsov, I.O. Pavlov, L. I. Lytkina, A. V. Drannikov, O. P. Kolomnikova // Storage and processing of agricultural raw materials. - 2005. - No. 4. - S.24-26. 2. Modeling the process of defrosting a “snow coat” on the surface of the evaporator [Text] / A.A. Shevtsov, I.O. Pavlov, L.I. Lytkina, A.V.Drannikov // Storage and processing of agricultural raw materials. - 2008. - No. 4. - S.26-29].

In this regard, difficulties arise in ensuring the synchronous operation of the working and reserve sections of the evaporator, which can lead to technological failures of the heat pump unit and a violation of the temperature regimes of drying and cooling the grain.

The method does not provide for the treatment of dried grain with an antioxidant to slow the oxidation of unsaturated fatty acids before storing it for storage, which does not allow maintaining the quality of the grain during long-term storage and causes rancidity of the finished product. The environmental safety problem has not been fully resolved, as exhaust air after active ventilation of the grain is released into the atmosphere.

An object of the invention is to improve the quality of grain of cereals and oilseeds, increase its shelf life, improve environmental safety while stabilizing the moisture and moisture characteristics of grain in the drying and storage processes.

To solve the technical problem of the invention, a method is proposed for stabilizing the thermal moisture characteristics of cereal and oilseed grains during its drying and storage, including control of drying processes in a shaft dryer and grain cooling during its active ventilation in silos of type silos using a heat pump unit for preparing a dried pump in the evaporator working section air and dividing it into two streams, one of which is fed to the active ventilation of the grain into silos, and the other to the drying of grain with further recirculation in a closed loop with sequential supply to the condenser, air heater, heat exchanger, cyclone, evaporator working section, which alternately with the backup section switches from the condensing mode to the regeneration mode when the current value of the heat transfer coefficient on the cooling surface of the evaporator reaches its maximum permissible value with an effect on power the compressor drive of the heat pump installation for controlling moisture content and temperature of the dried air with flow correction in the fresh air line feeding, new is the fact that in order to stabilize the characteristics of hydrothermal cereal grain and oilseed drying using an oscillating mode with alternating heating and cooling processes in I.S. grain drier consisting of heating sections and cooling; to implement an oscillatory drying mode, one part of the cold air after the evaporator is fed to the grain for cooling in the cooling section of a multi-section dryer, and the other is sent through the condenser of the heat pump unit and heaters to heat the grain in each of the dryer heating sections; saturated steam is used to heat air in the air heater before it is supplied to the dryer heating section and to regenerate the surface of the cooling element of the backup section of the evaporator of the heat pump installation, and saturated steam is obtained in the steam generator with electric heating elements and a safety valve, and the heat-generating evaporator formed in the heater and reserve section The condensate saturated steam units are diverted to the condensate collector and then again fed to the steam generator in a closed cycle mode for ying loss of water; the dried grain is treated with an antioxidant before it is stored, and the exhaust air after active ventilation of the grain is fed into the cyclone, while drying the grain in an oscillating mode, the grain temperature and humidity are additionally measured in the heating sections, grain temperature, air flow, antioxidant consumption in the cooling sections, saturated steam flow after the steam generator, steam pressure and condensate level in the steam generator, moreover, according to the grain temperature in the heating sections, the steam consumption is set in the heaters, and p grain moisture in the heating sections and the cooling temperature of the grain in the sections respectively set the flow of hot and cold air impact on power controlled fan drive; the ratio of the flow rates of dried grain and antioxidant supplied to the mixer is maintained by changing the consumption of antioxidant; by the pressure of saturated steam in the steam generator, the set steam generator output is set by affecting the power of the electric heating elements, when the condensate level in the steam generator decreases below a predetermined value, condensate is supplied from the condensate collector, and when the steam pressure in the steam generator reaches the upper limit value, the steam pressure is released through the safety valve.

The technical result of the invention is to improve the grain quality of cereals and oilseeds, increase its shelf life, improve environmental safety while stabilizing the moisture and moisture characteristics of grain in the drying and storage processes.

The drawing shows a diagram that implements the proposed method for stabilizing the thermal moisture characteristics of grain cereals and oilseeds during drying and storage.

The scheme contains a shaft grain dryer 1 with alternating sections of heating 2 and cooling grain 3; heat exchanger 4; heaters 5; hot air fans 6 in the heating zone 2; cold air supply fans 7 to cooling zones 3; cyclone 8; noria 9; mixer 10; silos 11; an air supply fan for actively ventilating grain 12 into silos 11; a steam generator 13 with a safety valve 14; pump 15; condensate collector 16; compressor heat pump installation 17; capacitor 18; evaporator with sections 19; thermostatic valve 20; flow distributors 21-24; lines: supply of wet grain 25 to heat exchanger 4, removal of dried grain 26 to mixer 10, input of antioxidant 27 to mixer 10, supply of grain treated with antioxidant 28 to silos 11, supply of dried and cooled drying agent in heating section 29 and cooling 30 grain dryers 1, air supply for active ventilation of grain 31 to silos 11, exhaust air from heating and cooling sections 32 grain dryers 1 to cyclone 8, exhaust air after active ventilation of grain 33 to cyclone 8, refrigerant recirculation Gent 34 in the heat pump installation, supplying saturated steam 35 to the heaters 5 and defrosting the 36 backup section of the evaporator 19 of the heat pump installation, removing condensate of saturated steam 37 from the heaters 5 and from the backup section of the evaporator 19 of the heat pump installation 38 to the condensate collector 16, replenishing fresh air 39 , 40; sensors: TE - temperature; ME - humidity; FE - flow rate; PE - pressure; HE - level; M - drive power; And - actuators; microprocessor 40; ↓ - input control channels; t - output control channels.

A method of stabilizing the thermal moisture characteristics of cereal and oilseeds during drying and storage is as follows.

Wet grain is fed through line 25 first to the heat exchanger 4, where it is heated by the heat of the spent drying agent, then the grain is fed to the heating section 2 of the shaft dryer 1, where it is blown with air, first heated in the condenser 18 of the heat pump unit, and then in the heater 5 As a result, the moisture content of the original grain is reduced. Next, the product enters the grain cooling section 3 of the shaft dryer 1, where it is cooled by air cooled in the working section of the evaporator 19. The subsequent alternation of heating and cooling of the product in zones 2 and 3, respectively, allows for oscillating drying modes, which reduce the rate of internal heat transfer compared to moisture transfer rate. At the same time, the grain temperature does not exceed the range of permissible values, and the decrease in humidity to the final one is achieved due to the thermal effect in the heating zones, the temperature regime in which is regulated by the value of the current grain moisture coming from the previous cooling zone to the subsequent heating zone. Moreover, the modes of heating and cooling will depend on the type of dried culture and its initial characteristics.

The dried grain with the help of elevator 9 is fed through line 26 to the mixer 10, where it is treated with an antioxidant before laying it for storage, which is sent to the mixer through line 27. Then, grain is fed through silo 28 to silos 11. Processing the grain with antioxidant before storing allows to achieve zero activity of the enzymes contained in it and to exclude the possibility of processes leading to a decrease in its quality during storage. This is especially true for grains of oilseeds, rich in unsaturated fatty acids.

The exhaust air after the heating and cooling sections of the grain dryer 1 along line 32, as well as the exhaust air from the silos after active ventilation through line 33, is sent to cyclone 8 to clean the suspended solids. The purified air using a flow distributor 21 is sent for drainage and cooling in the section of the evaporator 19 of the heat pump installation, operating in condensation mode. The dried and cooled drying agent using the distributor 22 is divided into two streams, one of which is fed to the grain for active ventilation in the silos 11 via line 31, and the other is sent to the implementation of oscillating drying modes with fresh air fed to these flows along lines 39 and 40, respectively.

By means of a distributor 23, one part of the cold air after the evaporator is fed through the fans 7 to the grain cooling section 3, and the other through the condenser 18 and heaters 5 using the fans 6 is sent to each of the grain heating sections 2.

To obtain saturated steam, a steam generator 13 is used with electric heating elements and a safety valve 14. By means of a distributor 24, one part of the obtained steam is fed through line 35 to air heaters 5 and the other along line 36 is sent to regenerate the surface of the cooling element of the backup section of the evaporator 19 of the heat pump installation . The use of saturated steam for defrosting (defrosting) makes it possible to ensure the synchronization of the backup and working sections of the evaporator of the heat pump installation due to the fact that the saturated steam has a higher heat transfer coefficient than air.

The condensate formed in the heaters 5 and after defrosting the backup section of the evaporator 19 is discharged along lines 37 and 38 to the condensate collector 16, respectively, and then again in the closed cycle mode, is pump 15 fed to the steam generator 13 to replenish the loss of water.

According to current information about the flow of grain in line 25, its temperature and humidity in the heating sections, obtained respectively from the sensors, the microprocessor 41, in accordance with the algorithm laid down in it, sets the mass and thermal air flow at the inlet to the heating section 2 of the shaft dryer 1 by exposure the power of the adjustable drives of the fans 6 and the flow rate of saturated steam in the heaters 5 by means of actuators. According to the current grain temperature in the cooling sections 3 of the shaft grain dryer 1, the microprocessor 41 sets the flow rate of cold air at the entrance to these sections by affecting the power of the adjustable fan drives 7.

According to the information of the sensors on the flow rate of exhaust air from the shaft dryer 1 and silos 11, its temperature and moisture content, the microprocessor 41 determines the amount of heat entering the working section of the evaporator 19 of the heat pump installation, depending on which it sets the flow of refrigerant in the recirculation line 34 through the actuator of the variable speed drive compressor 17, while providing the necessary cooling capacity of the heat pump installation. The refrigerant compressed by the compressor 17 is condensed in the condenser section 18 and throttled through the thermostatic valve 20 to the pressure at which it enters the working section of the evaporator 19. Evaporation of the refrigerant due to the heat of air allows it to cool below the dew point and drain it due to the loss of it moisture vapor.

The process of condensation of moisture contained in the air is accompanied by the formation of a “snow coat” on the cooling element of the working section of the evaporator 19, which leads to a decrease in the heat transfer coefficient from the refrigerant to the air through the wall of the cooling element when the thickness of the “snow coat” increases along the drying process and, as consequence, reduces the rate of air drainage.

According to the information of temperature and air and refrigerant flow sensors, the microprocessor continuously calculates the current value of the heat transfer coefficient and generates a signal deviating the current value of the heat transfer coefficient from the specified range of values, by which it adjusts the air-refrigerant flow ratio by changing the flow rate of the refrigerant in the recirculation line 34 by influencing the power drive the compressor 17 using the actuator. If the current value of the heat transfer coefficient deviates from the set value in the direction of decreasing, the microprocessor increases the refrigerating capacity of the heat pump installation. If the increase in refrigerating capacity (flow rate of the refrigerant) does not allow to bring the current value of the heat transfer coefficient to a predetermined range of values, then the microprocessor 41 by means of actuators disconnects the working section of the evaporator 19 from the refrigerant recirculation loop for regeneration and connects the backup section of the evaporator 19 to the recirculation loop by actuators condensation. The operation of actuators is synchronized. In this case, the flow distributor 20 by means of an actuator switches the flow of exhaust air supplied for drainage to the working section of the evaporator 19, which switches from the regeneration mode to the condensation mode.

The microprocessor 41 continuously monitors the temperature in various sections of the grain mass along the height of the silos 11. When the current grain temperature at any of the measuring points of the grain mass stored in the silos 11 deviates from the set value, the dried and cooled air after the working section of the evaporator 19 of the heat pump installation is increasing used by line 31 for cooling and actively ventilating the grain. Depending on the amount of grain mass in the silo 11, the microprocessor 41 sets a predetermined flow rate of the mixture of dried and fresh air supplied by the fan 12 to actively ventilate the grain by influencing the power of the adjustable drive using an actuator. In this case, the current value of the flow rate of the mixture is controlled by the corresponding sensor in line 31. From the current values of moisture content and temperature of the mixture of dried and fresh air, measured by the corresponding sensors in line 31, the microprocessor 41 determines the relative humidity of the mixture. Relative humidity is an important factor affecting the grain storage process. At this temperature, both low and high relative humidity can lead to deterioration of grain quality. The relative humidity at which grain spoilage begins depends on temperature. Therefore, according to information about the temperature of the grain at any of the points of measurement of the grain mass stored in the silos 11, the microprocessor 41 corrects the ratio of the flow rates of chilled and fresh air in line 31 using actuators. As soon as the grain temperature reaches equality or falls below a predetermined value, the microprocessor 41 stops the active ventilation of the grain and the entire flow of dried and cooled air through the distributor 22 and the actuator is fed to oscillating drying modes in the grain dryer 1.

During the drying process, the microprocessor 41 continuously monitors the moisture content of the mixture of dried and fresh air in line 29. With active ventilation of the grain, the ratio of the components of this mixture will inevitably change. Therefore, the microprocessor 41 continuously adjusts the drying mode depending on the moisture content of the dried grain, measured by a humidity sensor in line 26, by means of actuators acting on the change in temperature and flow rate of the mixture of dried and fresh air at the entrance to the heating zone 2 by changing the flow rate of saturated steam in the heaters 5 and power of adjustable fan drives 6.

The ratio of the flow rates of dried grain in line 26 and antioxidant in line 27, sent to the mixer 10, the microprocessor 41 supports by changing the flow of antioxidant using the appropriate actuator. In this case, the microprocessor 41 continuously calculates the current total value of the flow of grain and antioxidant in the mixer 10 according to the readings of the corresponding flow sensors. According to the calculated total flow rate, the microprocessor sets the power of the adjustable drive of the mixer 10 necessary to obtain a uniform mixture using the actuator. Moreover, the type of antioxidant and its required amount, sent to the mixer 10, depends on the type of processed grain and its characteristics after drying.

According to the pressure sensor, the microprocessor 41 performs continuous stabilization of the saturated steam pressure in the steam generator 13 by affecting the power of the electric heating elements by means of an actuator. In this case, the set value of the steam generator productivity is achieved, which is necessary for defrosting the evaporator section 19 and heating the air in the heaters 5. Information on the saturated steam flow rate obtained in the steam generator 13 is provided by the corresponding flow sensor.

Information about the current value of the condensate level in the steam generator 13 is transmitted via a sensor to the microprocessor 41. When the condensate level changes, the microprocessor performs on-off control by the drive of the feed pump 15 using an actuator. Moreover, it turns on the feed pump when the condensate level in the steam generator reaches the lower set value and turns it off when the upper set value is reached. In the case of technological and emergency failures in the operation of the steam generator associated with a possible increase in the pressure of saturated water vapor in its working volume, a safety valve 14 is provided.

The method of stabilizing the moisture and moisture characteristics of grain cereals and oilseeds during drying and storage is illustrated by the following example.

Consider the implementation of the proposed method by the example of drying flax seeds in a shaft grain dryer DSP-24 [V. Zhidko, V. A. Rezchikov, B.C. Ukolov. Grain drying and grain dryers. - M.: Kolos, 1982. - 239 p.] Followed by the introduction of an antioxidant and long-term storage in a metal granary with aerial chutes for active ventilation [EM Voblikov. Elevator technology. - Rostov n / a: Publishing center "Mart", 2001. - 192 p.].

The limits for controlling the temperature and air flow rate at the inlet to the heating section are respectively 60 ... 75 ° C and 14000 ... 22000 m ³ / h, and the air flow rate in the cooling section is 10,000 ... 18,000 m / h.

For long-term and reliable storage, providing the necessary aerobic conditions and preventing product spoilage, the method proposes aeration of flax seeds with a mixture of dried and atmospheric air at a flow of 0.1 ... 0.3 m ³ / min per cubic meter of grain mass for any length of aeration period in depending on the temperature of the seeds.

To prepare the dried air for subsequent drying and storage of flax seeds, a heat pump unit with the following technical data is used:

Cooling capacity, kW 30 ... 40 Refrigerant (Freon-12) R12 Compressor type single-stage piston Refrigerant temperature on inlet to the evaporator, ° C 10 ... 0 Cooling surface area evaporator, m ² 68.9 Permissible thickness of a snow coat, mm 16 ± 0.5 Permissible limits of change heat transfer coefficient, kW / (m ² · K) 5.8 ... 8.0

According to current sensors information about flax seed consumption 24 t / h in line 25, its temperature 28 ° C and humidity 18%, measured in heating section 2, microprocessor 41 sets the flow rate and temperature of the air sent to this section, respectively 22000 m ³ / h and 75 ° C. According to the current grain temperature of 55 ° C in the cooling section, the microprocessor sets the flow rate of cold air in this section to 18000 m ³ / h. Further, heating and cooling of flaxseeds alternately alternate. At the same time, the air flow in sections decreases, and the temperature increases in the above ranges, due to a decrease in the moisture of flax seeds and, accordingly, its mass.

The exhaust air from the dryer 1 and after active ventilation from the silos 11, with a temperature of 40 ° C, is sent via line 32 to the cyclone 8, and then to the working section of the evaporator 19 of the heat pump installation, operating in condensation mode. Due to the condensation of moisture from the air into the "snow coat" on the cooling surface of the working section of the evaporator, its moisture content is reduced to 0.001 ... 0.005 kg / kg. The flow of dried and cooled air is fed to line 31 for active ventilation of flax seeds stored in silos 11. If the temperature of flax seeds in the silos deviates from the set value of 20 ° C upwards, the microprocessor sets the ratio of the flow rate of dried and fresh air in line 31, at which the relative humidity of the mixture fed to active ventilation for a given seed storage temperature would provide a slowdown in physiological processes accompanied by heat. The duration of the aeration period is set by the microprocessor depending on the height of the silo and is 30 ... 45 min. If the temperature of the seeds at the measurement points is in the range of the set values corresponding to the relative humidity of the environment, then the active ventilation is stopped and the entire flow of dried and cooled air is supplied to the implementation of oscillating drying modes in the grain dryer 1.

The flax seeds dried in a grain dryer 1 with a moisture content of 9% go through line 26 to the mixer 10, where at the same time line 27 enters the antioxidant endox in the amount of 0.4% of the flow rate of dry flax seeds. The microprocessor 41 supports the indicated flow rate ratio of dried flax seeds and antioxidant using an actuator.

The current flow rate of saturated steam obtained in the steam generator 13 is continuously monitored by the microprocessor 41 according to the indications of the corresponding flow sensor. The microprocessor 41 performs continuous stabilization of the saturated steam pressure, which is 0.2 MPa, by affecting the power of the electric heating elements by means of an actuator.

The advantages of the proposed method follow from the results shown in the table.

Name of quality indicators Way Storage time, months Start one 2 3 four 5 Total seeding, CFU / g Famous 5.510 ³ 6.810 ³ 8.7 · 10 ³ 9.4 · 10 ³ 16.310 ³ 20.2 · 10 ³ Proposed 5.510 ³ 1,610 ³ 1,110 ³ 0.8 · 10 ³ 1.2 · 10 ³ 1.5 · 10 ³ The acid number of oil in mg KOH per 1 g of oil Famous 1.25 1,56 2.87 4,56 6.88 8.02 Proposed 1.25 1.28 1.94 2.07 2.74 3.56

As can be seen from the table, the decrease in total seeding in the proposed method is 4.0 · 10 ³ CFU / g, and a slight increase in the acid number by 2.31 mg KOH per 1 g of oil can increase the storage capacity of flax seeds by about 2 times.

The proposed method for stabilizing the moisture and moisture characteristics of cereal and oilseeds during drying and storage allows:

- to improve the grain quality of cereals and oilseeds due to the implementation of drying in oscillating modes by alternating heating and cooling intervals;

- increase the shelf life of grain due to its processing before laying the antioxidant for storage in the required quantities;

- to ensure synchronization in the operation of the backup and working sections of the evaporator of the heat pump unit, since saturated steam is used to defrost the “snow coat”, and ultimately improve the quality of the dried grain;

- improve the environmental safety of the process of stabilization of the thermo-moisture characteristics of grain during its drying and storage due to the recycling of exhaust air after active ventilation of the grain.

Claims (1)

A method of stabilizing the moisture and moisture characteristics of cereal and oilseeds during drying and storage, including controlling drying processes in a shaft dryer and cooling the grain when it is actively ventilated in silos, using a heat pump to prepare dried air in the evaporator working section and dividing it into two flow, one of which is fed to the active ventilation of the grain into silos, and the other to the drying of the grain, followed by recirculation in a closed circuit after The flow rate to the condenser, air heater, heat exchanger, cyclone, and the working section of the evaporator, which alternately switches from the condensing mode to the regeneration mode when the current section reaches the maximum heat transfer coefficient on the cooling surface of the evaporator and affects the compressor drive power of the heat pump unit during regulation moisture content and temperature of the dried air with a correction for the flow of fresh air in the feed line, characterized in then hydrothermal stabilization characteristics cereal grain and oilseed drying using an oscillating mode with alternating heating and cooling processes in I.S. grain drier consisting of heating sections and cooling; to implement an oscillatory drying mode, one part of the cold air after the evaporator is fed to the grain for cooling in the cooling section of a multi-section dryer, and the other is sent through the condenser of the heat pump unit and heaters to heat the grain in each of the dryer heating sections; saturated steam is used to heat air in the air heater before feeding it into the dryer heating section and to regenerate the surface of the cooling element of the backup section of the evaporator of the heat pump installation, and saturated steam is obtained in the steam generator with electric heating elements and a safety valve, while the heat pump formed in the heater and the backup section of the evaporator the condensate saturated steam is removed to the condensate collector and then again fed to the steam generator in a closed cycle mode for replenishment of loss of water; the dried grain is treated with an antioxidant before it is stored, and the exhaust air after active ventilation of the grain is fed into the cyclone, while drying the grain in an oscillating mode, the grain temperature and humidity are additionally measured in the heating sections, grain temperature, air flow, antioxidant consumption in the cooling sections, saturated steam flow after the steam generator, steam pressure and condensate level in the steam generator, moreover, according to the grain temperature in the heating sections, the steam consumption is set in the heaters, and according to grain moisture in the heating sections and grain temperature in the cooling sections respectively set the flow rate of hot and cold air by affecting the power of the adjustable fan drives; the ratio of the flow rates of dried grain and antioxidant supplied to the mixer is maintained by changing the consumption of antioxidant; by the pressure of saturated steam in the steam generator, the set steam generator output is set by affecting the power of the electric heating elements, when the condensate level in the steam generator decreases below a predetermined value, condensate is supplied from the condensate collector, and when the steam pressure in the steam generator reaches the upper limit value, the steam pressure is released through the safety valve.