Low-temperature cyclic utilization type efficient energy-saving grain drying machine

Abstract

The invention relates to the technical field of grain drying equipment, in particular to a low-temperature recycling type efficient energy-saving grain drying machine which comprises an air inlet channel, an air outlet channel, a rotational flow filtering mechanism and an adsorption filtering mechanism. The air inlet channel is connected with an air inlet system; the air outlet channel is connected with an exhaust system; the rotational flow filtering mechanism is arranged in the air outlet channel; the adsorption filtering mechanism is connected with the rotational flow filtering mechanism; water and dust particles in high-temperature waste gas are separated and then directly introduced into the evaporator, the evaporator is heated and then introduced into the heat exchanger to be heated, the filtered and heated gas flows through the outer surface of a channel where the waste gas passes, and redundant heat of the filtered and heated gas is transferred to the waste gas; waste heat recovery is achieved, and the temperature of gas entering the drying tower is controlled to be appropriate; the problems that when dust exists in grains, dried damp and hot waste gas carries the dust to be discharged, and the heat exchange efficiency is gradually reduced when the waste gas carrying the dust is recycled are solved.

Description

Technical Field

[0001] The invention relates to the technical field of grain drying equipment, and in particular to a low-temperature recycling type high-efficiency energy-saving grain dryer. Background Art

[0002] Low-temperature circulation grain dryer is a device that uses hot air circulation to dry grains. Low-temperature circulation drying can reduce the damage of high temperature to the nutritional content, taste and appearance of grains, and the temperature and humidity can be adjusted according to different crops to achieve the best drying effect.

[0003] At present, the low-temperature circulating grain dryer is mainly composed of a dryer body and a heat pump system. When wheat and rice, which contain dust and impurities, are circulated and dried, the dust therein will be discharged together with the exhaust gas. When the exhaust gas is recycled, the dust in the exhaust gas will block the gap between the evaporator fins, thereby causing the heat exchange efficiency of the evaporator to decrease. Therefore, when the grains containing a lot of dust and impurities are circulated and dried, the exhaust gas will be directly discharged without recycling the waste heat, resulting in a waste of heat energy. In view of the above problems, the prior art proposes a solution. The patent publication number is CN108489251B, which is a heat pump type low-temperature circulating grain dryer with waste heat recovery. By setting an air heat exchanger, the exhaust gas is used to heat exchange the cold air inhaled from the outside before the exhaust gas is discharged, so that the new air inhaled from the outside can obtain heat. At this time, the new air with increased temperature is introduced into the evaporator position. The evaporator can evaporate the refrigerant inside it quickly under the action of the heat of the new air, which helps the heat pump system to improve the working efficiency, recycle the heat in the exhaust gas, improve energy utilization, and save energy and protect the environment.

[0004] Although the existing technology has solved the problem that the waste heat in the exhaust gas cannot be recycled when the grains with a lot of dust and impurities are cyclically dried, the following problems still exist: when the grains are cyclically dried, the exhaust gas will carry away the moisture in the grains. At this time, the exhausted exhaust gas is high temperature and high humidity and carries dust. After the exhaust gas is passed into the air heat exchanger, the dust carried therein will adhere to the surface of the inner cavity of the air exchanger. Since the humidity of the exhaust gas is high, the dust will be more easily attached to the surface of the inner cavity of the air exchanger. On the one hand, with the deposition of dust, the flow area of ​​the air heat exchange will be reduced, resulting in restricted airflow and equipment blockage, thereby affecting the normal heat exchange process. On the other hand, a layer of dirt will gradually form, which will hinder the transfer of heat, reduce the heat exchange efficiency, and make the waste heat recovery rate low, and it is impossible to effectively save energy.

[0005] In view of the above situation, in order to overcome the above technical problems, the present invention proposes a low-temperature recycling type high-efficiency energy-saving grain dryer. Summary of the invention

[0006] The present invention provides a low-temperature recycling type high-efficiency and energy-saving grain dryer, which solves the problem that when dust exists in the grains, the hot and humid exhaust gas after drying will be discharged with the dust, and the hot and humid exhaust gas carrying dust will cause the heat exchange efficiency to gradually decrease when recycled; the moisture and dust particles in the high-temperature exhaust gas are separated and directly introduced into the evaporator position, and the evaporator is heated before being introduced into the heat exchanger for heating. Since the temperature of the heated gas after the heat exchange is higher than the suitable temperature for grain drying, the filtered and heated gas is guided to the outer surface of the channel through which the exhaust gas passes, and the excess heat is transferred to the exhaust gas, thereby realizing waste heat recovery and controlling the temperature of the gas entering the drying tower to be suitable.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A low-temperature recycling type high-efficiency and energy-saving grain dryer, comprising a drying tower, a feeding system and an air inlet system; also comprising an exhaust system, a heating system and a circulating air duct; the exhaust system is connected to the drying tower; the heating system is connected to the air inlet system through the circulating air duct; the circulating air duct comprises an air inlet channel, an air outlet channel, a cyclone filter mechanism and an adsorption filter mechanism; the air inlet channel is connected to the air inlet system; the air outlet channel is connected to the exhaust system, and the air outlet channel is arranged inside the air inlet channel, and the exhaust gas flows out from the exhaust system and enters the air outlet channel; the cyclone filter mechanism is connected to the air outlet channel; the adsorption filter mechanism is connected to the cyclone filter mechanism, the exhaust gas flows from the air outlet channel through the cyclone filter mechanism and then enters the adsorption filter mechanism, the exhaust gas flowing out from the adsorption filter mechanism will flow into the heating system, and finally the filtered exhaust gas enters the air inlet channel from the heating system and flows through the outer surface of the air outlet channel.

[0009] Preferably, the air outlet channel includes a connecting section, a heating section and an outflow section; the connecting section is connected to the exhaust system; the heating section is arranged inside the air inlet channel; and the outflow section is connected to the heating system.

[0010] In the above scheme, by setting the abandoned air outlet channel inside the air inlet channel, the heat overflowed during the circulation process of the heated gas can be fully utilized before entering the drying tower, and the overflow heat is used to heat the exhaust gas and the fresh gas introduced from the outside, so that the exhaust gas and the fresh gas can reach the heating system at a higher temperature, so that the refrigerant in the evaporator can evaporate quickly, thereby improving the circulation efficiency; and the gas temperature after heat exchange in the heating system is about 50-80 degrees, and the gas temperature needs to be controlled at about 40-50 degrees before entering the drying tower. At this time, the excess heat can be used to heat the newly introduced gas and exhaust gas, so that the heat can be fully recovered and utilized.

[0011] Preferably, the heating system includes a shell, an evaporator, a compressor, a condenser and a heat exchanger; the shell is connected to the outflow section; the evaporator is arranged in the shell, and the outlet position of the outflow section is opposite to the position of the evaporator; the compressor is connected to the evaporator; the condenser is connected to the evaporator; and the heat exchanger is connected between the compressor and the condenser.

[0012] In the above scheme, the gas obtained by mixing the filtered and dehumidified exhaust gas and the heated fresh air is introduced into the evaporator position, thereby helping the refrigerant in the evaporator to evaporate quickly, thereby ensuring the evaporation efficiency even in a cold environment. The filtered exhaust gas is directly used to contact the evaporator instead of exchanging heat with the fresh air introduced from the outside, further avoiding heat loss caused by heat exchange and improving the utilization rate of waste heat.

[0013] Preferably, the exhaust system includes an exhaust gas pipe and an exhaust impeller; the exhaust gas pipe is connected between the drying tower and the connecting section; the exhaust impeller is arranged at the connecting position of the exhaust gas pipe and the connecting section; the cyclone filtering mechanism includes a cyclone chamber, an ash accumulation trough and a riser; the cyclone chamber is connected to the air outlet channel; the ash accumulation trough is arranged below the cyclone chamber; the riser is arranged at the upper part of the center of the cyclone chamber; the connecting section includes a hot channel and a cold channel; the hot channel is tangentially connected to the upper part of the cyclone chamber; the cold channel is tangentially connected to the middle part of the cyclone chamber.

[0014] In the above scheme, the dust, impurities and moisture in the exhaust gas can be preliminarily separated through the structure of the cyclone separator, and compared with the ordinary cyclone separator, the low-temperature air is introduced from the middle of the cyclone chamber, and the high-temperature exhaust gas is introduced from the upper part of the cyclone chamber. On the one hand, a temperature difference is formed between the upper and lower layers of the cyclone chamber. The temperature of the upper layer is high, and the density of moisture separated from the high-temperature exhaust gas at the upper layer decreases. At this time, when the high-temperature exhaust gas rotates downward along the inner wall of the cyclone chamber, it will be easier to drive the water droplets to flow downward, and the water droplets will drive the dust to flow downward together, so that the moisture and dust are accelerated to enter the dust accumulation tank, so that the gas flowing out of the cyclone filter mechanism is drier and does not carry dust. On the other hand, compared with the fresh air entering from the outside, the high-temperature exhaust gas contains more dust and moisture. Entering from the upper layer can extend its cyclone path, making the separation of dust and moisture more thorough.

[0015] Preferably, the upper portion of the riser is connected to the heating section; and the air inlet channel is connected to the upper portion of the swirl chamber.

[0016] In the above scheme, the heat in the air inlet channel is used to further heat the upper part of the swirl chamber, so that heat accumulation can be formed in the upper part of the swirl chamber, thereby ensuring the temperature difference between the upper and lower parts of the swirl chamber, so that the high-temperature exhaust gas can quickly condense when it reaches the lower layer of the swirl chamber and meets the low-temperature air entering from the outside, and then all the moisture in the gas can be thrown out under the action of the swirl, so that the separation effect is further improved.

[0017] Preferably, the adsorption and filtration mechanism comprises an activated carbon layer and a cyclone plate; the activated carbon layer is arranged in the riser; and the cyclone plate is arranged below the activated carbon layer.

[0018] In the above scheme, the moisture in the high-temperature gas is adsorbed by a high-temperature resistant activated carbon layer. Compared with using the condensation method to filter out the moisture in the gas, the use of activated carbon for filtration has less impact on the heat in the gas, which can reduce heat loss and thus improve heat utilization; and under the action of the cyclone separation in the previous step, most of the moisture and dust can be separated out, thereby reducing the adsorption burden of the activated carbon and allowing the activated carbon to work for a long time; the adsorption effect of the activated carbon will be significantly improved when the temperature rises, so the activated carbon layer located at the upper part of the cyclone chamber can improve the adsorption effect, thereby completely absorbing the moisture and dust particles in the exhaust gas and the fresh air, and the rising gas forms a cyclone through the cyclone plate, so that it enters the activated carbon layer more evenly, thereby improving the filtering effect.

[0019] Preferably, the air inlet channel includes a recovery section and an output section; one end of the recovery section is connected to the shell, and the other end is connected to the heat exchanger; one end of the output section is connected to the heat exchanger, and the other end is connected to the air inlet system.

[0020] In the above scheme, since the air outlet channel passes the filtered gas into the position of the evaporator to help the evaporator quickly evaporate the refrigerant, after the gas passes through the evaporator and heats its fins, the gas will enter the heat exchanger from the recovery section, so that the gas will be heated again in the heat exchanger. Since the gas temperature itself is relatively high, the gas residence time in the heat exchanger can be shortened and quickly enter the drying tower. On the one hand, it can save heat energy loss, and on the other hand, it can speed up the gas circulation speed, thereby improving the drying efficiency of grains.

[0021] Preferably, a sealed cavity is provided in the shell; the evaporator is arranged in the sealed cavity; and the two side walls of the sealed cavity are respectively connected to the outflow section and the recovery section.

[0022] In the above scheme, by setting the evaporator in the sealed cavity, the filtered gas enters the sealed cavity. On the one hand, it can avoid the high temperature gas after filtration affecting the normal operation of other equipment. On the other hand, it can reduce the heat transfer of the gas to other components, further avoid heat loss, thereby improving heat utilization and achieving the purpose of saving.

[0023] The beneficial effects of the present invention are as follows:

[0024] 1. Compared with the existing low-temperature circulating grain dryer, the present invention separates the moisture and dust particles in the exhaust gas by passing the exhaust gas and the fresh air into the cyclone chamber. In the separation process, the exhaust gas enters from the upper layer and the fresh air enters from the lower layer. On the one hand, a temperature difference can be formed between the upper and lower layers of the cyclone chamber, thereby improving the moisture separation effect, ensuring that the gas reaching the evaporator and the drying tower is dry, and ensuring the waste heat recovery effect and the grain drying effect. On the other hand, the high-humidity exhaust gas carrying a large amount of dust enters the cyclone chamber from the upper layer, and the cyclone path is longer and the separation time is longer, which can effectively separate the moisture and dust, ensure that the surface of the evaporator will not scale, and improve the evaporation rate of the evaporator. The waste heat can be fully recovered and utilized to achieve the purpose of energy saving.

[0025] 2. The present invention passes the filtered exhaust gas directly into the evaporator to help the evaporator evaporate quickly, and after passing through the evaporator, it will enter the heat exchanger for heating, and then enter the drying tower. Since the moisture and dust content in the filtered exhaust gas is extremely low, the grain drying effect can be further improved, and all the moisture and dust in the grain can be taken away. Moreover, since the temperature of the filtered exhaust gas is still high, the exchange time in the heat exchanger can be shortened. On the one hand, the grain drying cycle speed is effectively improved, and the grain drying efficiency and drying effect are improved. On the other hand, it can reduce heat energy loss, so that the heat generated by the compressor each compression can be supplied for multiple cycles, further improving the energy saving effect.

[0026] 3. The present invention arranges the channel for the flow of gas heated by the heat exchanger outside the channel after the exhaust gas is filtered. Since the filtered gas is a mixture of high-temperature exhaust gas and low-temperature fresh air from the outside, its temperature will be reduced to a certain extent. The temperature of the gas heated by the heat exchanger is usually higher than the temperature that can be directly introduced into the drying tower. At this time, the heated gas needs to be cooled. The excess heat will be transferred to the filtered mixed gas when passing through the outside of the air outlet channel, so that the mixed gas helps the evaporator to evaporate quickly when it reaches the evaporator position, thereby increasing the speed of the drying cycle and thus the drying effect. In addition, all the waste heat generated in the overall drying cycle is recycled to improve the energy-saving effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 It is the overall structure diagram of the present invention;

[0029] Figure 2 It is the internal structure diagram of the cyclone filter mechanism of the present invention;

[0030] Figure 3 It is a schematic diagram of the heating system structure of the present invention;

[0031] Figure 4 It is a positional relationship diagram of the heating section and the output section of the present invention;

[0032] Figure 5 yes Figure 3 A magnified view of the structure at center;

[0033] Figure 6 is a schematic diagram of the exhaust system structure of the present invention;

[0034] Figure 7 yes Figure 3 A magnified view of the structure at B in the middle;

[0035] Figure 8 It is a flow diagram of different gases in the present invention;

[0036] In the figure: 1. drying tower; 2. feeding system; 3. air intake system; 4. exhaust system; 41. exhaust gas duct; 42. exhaust impeller; 5. heating system; 51. shell; 511. sealed chamber; 52. evaporator; 53. compressor; 54. condenser; 55. heat exchanger; 6. circulating air duct; 61. air intake channel; 611. recovery section; 612. output section; 62. air outlet channel; 621. connecting section; 6211. hot channel; 6212. cold channel; 622. heating section; 623. outflow section; 63. cyclone filter mechanism; 631. cyclone chamber; 632. ash accumulation trough; 633. riser; 64. adsorption filter mechanism; 641. activated carbon layer; 642. cyclone plate. DETAILED DESCRIPTION

[0037] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0038] See also Figures 1 to 8The present invention provides a low-temperature recycling type high-efficiency energy-saving grain dryer, and the technical solution is as follows:

[0039] As a specific embodiment of the present invention, refer to Figure 1 and Figure 2 A low-temperature recycling type high-efficiency energy-saving grain dryer, comprising a drying tower 1, a feeding system 2 and an air intake system 3; further comprising an exhaust system 4, a heating system 5 and a circulating air duct 6; the exhaust system 4 is connected to the drying tower 1; the heating system 5 is connected to the air intake system 3 through the circulating air duct 6; the circulating air duct 6 comprises an air intake channel 61, an air outlet channel 62, a cyclone filter mechanism 63 and an adsorption filter mechanism 64; the air intake channel 61 is connected to the air intake system 3; the air outlet channel 62 is connected to the exhaust system 4, and the air outlet channel 62 is arranged inside the air intake channel 61, and the exhaust gas flows out of the exhaust system 4 and enters the air outlet channel 62; the cyclone filter mechanism 63 is connected to the air outlet The exhaust gas flows from the air outlet channel 62 through the cyclone filter mechanism 63 and then enters the adsorption filter mechanism 64. The exhaust gas flowing out from the adsorption filter mechanism 64 will flow into the heating system 5. Finally, the filtered exhaust gas enters the air inlet channel 61 from the heating system 5 and flows through the outer surface of the air outlet channel 62. Since the gas temperature is high after heating, it needs to be cooled to a temperature suitable for grain drying before being introduced into the drying tower 1. At this time, when flowing through the outer surface of the air outlet channel 62, the excess heat can be fully utilized and transferred to the filtered exhaust gas, so that it can help the heating system 5 to increase the speed of the heating cycle.

[0040] As a specific embodiment of the present invention, refer to Figure 2 and Figure 3 , the air outlet channel 62 includes a connecting section 621, a heating section 622 and an outflow section 623; the connecting section 621 is connected to the exhaust system 4; the heating section 622 is arranged inside the air inlet channel 61; the outflow section 623 is connected to the heating system 5. By arranging the abandoned air outlet channel inside the air inlet channel 61, the heat overflowed during the circulation of the heated gas before entering the drying tower 1 can be fully utilized, and the overflowed heat is used to heat the waste gas and the fresh gas introduced from the outside, so that the waste gas and the fresh gas can reach the heating system 5 at a higher temperature, so that the refrigerant in the evaporator 52 can evaporate quickly, and the circulation efficiency is improved; and the gas temperature after heat exchange in the heating system 5 is about 50-80 degrees, and the gas temperature needs to be controlled at about 40-50 degrees before entering the drying tower 1. At this time, the excess heat can be used to heat the newly introduced gas and waste gas, so that the heat can be fully recycled.

[0041] As a specific embodiment of the present invention, refer to Figure 2 , Figure 3 and Figure 4 The heating system 5 includes a housing 51, an evaporator 52, a compressor 53, a condenser 54 and a heat exchanger 55; the housing 51 is connected to the outflow section 623; the evaporator 52 is arranged in the housing 51, and the outlet position of the outflow section 623 is directly opposite to the position of the evaporator 52; the compressor 53 is connected to the evaporator 52; the condenser 54 is connected to the evaporator 52; the heat exchanger 55 is connected between the compressor 53 and the condenser 54. By introducing the mixed gas of the filtered and dehumidified exhaust gas and the heated fresh air into the position of the evaporator 52, the refrigerant in the evaporator 52 is helped to evaporate quickly, and the evaporation efficiency can be guaranteed in a cold environment, and the filtered exhaust gas is directly used to contact the evaporator 52 instead of the fresh air introduced from the outside for heat exchange, so as to further avoid the heat loss caused by the heat exchange and improve the utilization rate of the waste heat.

[0042] As a specific embodiment of the present invention, refer to Figure 3 , Figure 5 , Figure 6 and Figure 8The exhaust system 4 includes an exhaust pipe 41 and an exhaust impeller 42; the exhaust pipe 41 is connected between the drying tower 1 and the connecting section 621; the exhaust impeller 42 is arranged at the connecting position of the exhaust pipe 41 and the connecting section 621, and the exhaust impeller 42 has two sets of impellers on the same axis, which are respectively used to guide the exhaust gas and extract the fresh air from the outside. The two sets of impellers are separated by the connecting section 621, so the exhaust gas and the fresh air enter different channels respectively without affecting each other; the cyclone filtering mechanism 63 includes a cyclone chamber 631, an ash accumulation tank 632 and a riser 633; ​​the cyclone The flow cavity 631 is connected with the air outlet channel 62; the dust accumulation groove 632 is arranged below the cyclone cavity 631; the riser 633 is arranged at the upper part of the center of the cyclone cavity 631; the connecting section 621 includes a hot channel 6211 and a cold channel 6212; the hot channel 6211 is tangentially connected with the upper part of the cyclone cavity 631; the cold channel 6212 is tangentially connected with the middle part of the cyclone cavity 631; under the action of the tangential connection, the exhaust gas and the new air can form a cyclone downward flow trend when entering the cyclone cavity 631, and at this time, the exhaust gas and the new air will be separated from moisture and dust under the action of centrifugal force. The cyclone separator-like structure of the cyclone chamber 631 can initially separate dust, impurities and moisture in the exhaust gas. After the separation is completed, the clean and dry gas will be discharged through the central riser 633. Compared with the ordinary cyclone separator, the low-temperature air is introduced from the middle of the cyclone chamber 631, and the high-temperature exhaust gas is introduced from the upper part of the cyclone chamber 631. On the one hand, a temperature difference is formed between the upper and lower layers of the cyclone chamber 631. The temperature of the upper layer is high, and the density of moisture separated from the high-temperature exhaust gas at the upper position decreases. At this time, the high temperature When the exhaust gas rotates downward along the inner wall of the cyclone chamber 631, it will be easier to drive the water droplets to flow downward, and the water droplets will drive the dust to flow downward together, so that the water and dust are accelerated to enter the dust accumulation groove 632, ensuring that the separated exhaust gas will not carry the water and dust up again, so that the gas flowing out of the cyclone filter mechanism 63 is drier and does not carry dust. On the other hand, compared with the fresh air entering from the outside, the high-temperature exhaust gas contains more dust and water. Entering from the upper layer can extend the cyclone path, making the separation of dust and water more thorough.

[0043] As a specific embodiment of the present invention, refer to Figure 3 and Figure 8, the upper part of the rising pipe 633 is connected to the heating section 622; the air inlet channel 61 is connected to the upper part of the swirl chamber 631. The upper part of the swirl chamber 631 is further heated by the heat in the air inlet channel 61, so that the upper part of the swirl chamber 631 can form heat accumulation, thereby ensuring the temperature difference between the upper and lower parts of the swirl chamber 631, so that the high-temperature exhaust gas can quickly condense when it reaches the lower layer of the swirl chamber 631 and meets the low-temperature air entering from the outside, and then all the moisture in the gas can be thrown out under the action of the swirl, so that the separation effect is further improved. The height of the swirl chamber 631 can be designed according to the different moisture content to be separated. When used for drying grains with high moisture content, the height of the swirl chamber 631 can be increased, thereby extending the separation time and achieving the effect of improving the separation effect.

[0044] As a specific embodiment of the present invention, refer to Figure 3 , Figure 5 and Figure 8 The adsorption and filtering mechanism 64 includes an activated carbon layer 641 and a cyclone plate 642 ; the activated carbon layer 641 is arranged in the riser 633 ; and the cyclone plate 642 is arranged below the activated carbon layer 641 . The high temperature resistant activated carbon layer 641 is used to adsorb moisture in the high temperature gas. Compared with using the condensation method to filter out moisture in the gas, the use of activated carbon for filtration has less impact on the heat in the gas, which can reduce heat loss and thus improve the utilization rate of heat; and most of the moisture and dust can be separated out under the action of the cyclone separation in the previous step, thereby reducing the adsorption burden of the activated carbon and allowing the activated carbon to work for a long time; the adsorption effect of the activated carbon will be significantly improved when the temperature rises, so the activated carbon layer 641 located at the upper position of the cyclone chamber 631 can improve the adsorption effect, thereby completely absorbing the moisture and dust particles in the exhaust gas and the fresh air, and the rising gas is formed into a cyclone through the cyclone plate 642, so that the distribution of the gas when entering the activated carbon layer 641 is more uniform, thereby improving the filtering effect; through the adsorption effect of the activated carbon layer 641 and the cyclone filtering mechanism 63, it can be prevented that part of the moisture in the gas that reaches the bottom of the cyclone chamber 631 and then rises escapes.

[0045] As a specific embodiment of the present invention, refer to Figure 3 , Figure 4 and Figure 7The air inlet channel 61 includes a recovery section 611 and an output section 612; one end of the recovery section 611 is connected to the housing 51, and the other end is connected to the heat exchanger 55; one end of the output section 612 is connected to the heat exchanger 55, and the other end is connected to the air inlet system 3. Since the air outlet channel 62 passes the filtered gas to the location of the evaporator 52 to help the evaporator 52 quickly evaporate the refrigerant, after the gas passes through the evaporator 52 and heats its fins, the gas will enter the heat exchanger 55 from the recovery section 611, so that the gas will be heated again in the heat exchanger 55. Since the gas temperature itself is relatively high, the gas can be kept in the heat exchanger 55 for a shorter time and quickly enter the drying tower 1. On the one hand, it can save heat energy loss, and on the other hand, it can speed up the gas circulation speed, thereby improving the drying efficiency of grains.

[0046] As a specific embodiment of the present invention, refer to Figure 3 , Figure 4 and Figure 7 , a sealed cavity 511 is arranged in the shell 51; the two side walls of the sealed cavity 511 are respectively connected to the outflow section 623 and the recovery section 611; the evaporator 52 is arranged in the sealed cavity 511. By arranging the evaporator 52 in the sealed cavity 511, the filtered gas enters the sealed cavity 511, which, on the one hand, avoids the high temperature gas after filtration from affecting the normal operation of other equipment, and on the other hand, can reduce the heat transfer of the gas to other components, further avoid heat loss, thereby improving heat utilization and achieving the purpose of saving. The inner surface of the sealed cavity 511 can be added with heat preservation material to avoid heat loss, so that the sealed cavity 511 is always kept at a higher temperature, so that the refrigerant in the evaporator 52 can maintain rapid evaporation, improve the circulation speed of the entire drying cycle, and thus improve the drying efficiency and drying effect of the grains.

[0047] Working process: the exhaust gas discharged from the drying tower 1 after drying enters the air outlet channel 62 through the exhaust system 4, and the exhaust gas enters the cyclone chamber 631 from the upper part of the cyclone chamber 631 through the air outlet channel 62. Under the action of the exhaust impeller 42, the new air from the outside enters the cyclone chamber 631 from the middle part of the cyclone chamber 631; in the cyclone chamber 631, the exhaust gas and the new air will separate the moisture and dust therein, and the separated gas will be further filtered by the adsorption filter mechanism 64, and the filtered gas will flow to the evaporator 52 to help the evaporator 52 quickly evaporate the refrigerant, and then enter the heat exchanger 55 for heating, and the heated gas flows through the outer surface of the heating section 622, and transfers the excess heat to the filtered mixed gas, and after transferring the excess heat, it enters the drying tower 1 to complete the cycle.

[0048] Specifically, the exhaust gas discharged from the drying tower 1 after drying enters the exhaust gas pipe 41. Under the action of the exhaust impeller 42, the exhaust gas will enter the connecting section 621. In order to separate the moisture and dust in the exhaust gas and replenish the gas lost in the drying process, the exhaust gas enters the upper part of the cyclone chamber 631 through the hot channel 6211, and the fresh air from the outside enters the middle part of the cyclone chamber 631 through the cold channel 6212. When the exhaust gas and the fresh air enter the cyclone chamber 631, a cyclone downward flow trend is formed. At this time, the exhaust gas and the fresh air will separate the moisture and dust under the action of centrifugal force, and the clean dry gas after separation will flow out of the cyclone chamber 631 from the central riser 633. Since the exhaust gas entering from the upper part is high-temperature gas and the outside air entering from the middle part is low-temperature gas, the cyclone chamber 631 A temperature difference will be formed between the upper and middle parts, which can accelerate the condensation of moisture in the high-temperature exhaust gas and drive the dust separated on the side wall of the cyclone chamber 631 to flow quickly to the dust accumulation groove 632, so as to prevent dust and moisture from escaping from the cyclone chamber 631 with the rising gas, thereby ensuring the separation effect of exhaust gas and fresh gas; in order to prevent the rising gas from carrying a small amount of moisture and dust, the rising gas will pass through the adsorption and filtering mechanism 64, and the gas will form a cyclone under the action of the cyclone plate 642 during the rising process, so as to achieve the purpose of uniform contact with the activated carbon layer 641, so that the activated carbon layer 641 can filter out the remaining dust and moisture in the gas, and because the activated carbon layer 641 is located at the upper part of the cyclone chamber 631 and is at a higher temperature, its adsorption effect will be further improved;

[0049] Since the gas flowing out of the adsorption filter mechanism 64 is a mixture of high-temperature exhaust gas and low-temperature fresh air from the outside, its overall temperature will drop, and the temperature of the gas after heat exchange in the heating system 5 is about 50-80 degrees. It is necessary to control the gas temperature at about 40-50 degrees before passing it into the drying tower 1. In order to recycle the excess heat of the heated gas and ensure that the filtered mixed gas can help the evaporator 52 to quickly evaporate the refrigerant; the gas flowing out of the adsorption filter mechanism 64 will enter the heating section 622, and the air inlet channel 61 through which the heated gas flows is sleeved on the outside of the heating section 622. At this time, the heated gas will flow through the outer surface of the heating section 622, so that the heated gas The excess heat in the body is transferred to the filtered mixed gas, so that all the excess heat in the entire drying cycle is recycled and utilized, thereby improving the energy-saving effect; the temperature of the filtered mixed gas increases after absorbing the excess heat of the heated gas, and after flowing through the heating section 622, the mixed gas enters the sealed cavity 511, so that the refrigerant in the evaporator 52 can evaporate quickly, and the mixed gas will enter the recovery section 611 after flowing through the surface of the evaporator 52, and enter the heat exchanger 55 through the recovery section 611 for heating, and the heated gas enters the output section 612, flows through the outer surface of the heating section 622 to reduce the temperature to a temperature suitable for drying, and then enters the drying tower 1 for a drying cycle.

[0050] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected, and the scope of the present invention to be protected is defined by the attached claims and their equivalents.

Claims

1. A low-temperature recycling type high-efficiency energy-saving grain dryer, comprising a drying tower (1), a feeding system (2) and an air intake system (3); characterized in that: The invention also comprises an exhaust system (4), a heating system (5) and a circulating air duct (6); the exhaust system (4) is connected to the drying tower (1); the heating system (5) is connected to the air inlet system (3) via the circulating air duct (6); the circulating air duct (6) comprises an air inlet channel (61), an air outlet channel (62), a cyclone filter mechanism (63) and an adsorption filter mechanism (64); the air inlet channel (61) is connected to the air inlet system (3); the air outlet channel (62) is connected to the exhaust system (4), and the air outlet channel (62) is arranged through the air inlet channel (61). Inside, the exhaust gas flows out of the exhaust system (4) and enters the air outlet channel (62); the cyclone filter mechanism (63) is connected to the air outlet channel (62); the adsorption filter mechanism (64) is connected to the center of the cyclone filter mechanism (63); the exhaust gas flows from the air outlet channel (62) through the cyclone filter mechanism (63) and then enters the adsorption filter mechanism (64); the exhaust gas flowing out of the adsorption filter mechanism (64) flows into the heating system (5); the filtered exhaust gas enters the air inlet channel (61) from the heating system (5) and flows through the outer surface of the air outlet channel (62).

2. The low-temperature recycling type high-efficiency energy-saving grain dryer according to claim 1 is characterized in that: The air outlet channel (62) comprises a connecting section (621), a heating section (622) and an outflow section (623); the connecting section (621) is connected to the exhaust system (4); the heating section (622) is arranged inside the air inlet channel (61); and the tail of the outflow section (623) is connected to the heating system (5).

3. A low-temperature recycling type high-efficiency energy-saving grain dryer according to claim 2, characterized in that: The heating system (5) comprises a shell (51), an evaporator (52), a compressor (53), a condenser (54) and a heat exchanger (55); the shell (51) is connected to an outflow section (623); the evaporator (52) is arranged in the shell (51), and the outlet position of the outflow section (623) is directly opposite to the position of the evaporator (52); the compressor (53) is connected to the evaporator (52); the condenser (54) is connected to the evaporator (52); and the heat exchanger (55) is connected between the compressor (53) and the condenser (54).

4. A low-temperature recycling type high-efficiency energy-saving grain dryer according to claim 2, characterized in that: The exhaust system (4) comprises an exhaust gas pipeline (41) and an exhaust impeller (42); the exhaust gas pipeline (41) is connected between the drying tower (1) and the connecting section (621); the exhaust impeller (42) is arranged at the connecting position of the exhaust gas pipeline (41) and the connecting section (621); the cyclone filtering mechanism (63) comprises a cyclone chamber (631), an ash accumulation tank (632) and a riser (633); the cyclone chamber (631) and The ash accumulation groove (632) is arranged below the cyclone chamber (631); the riser (633) is arranged at the upper part of the center of the cyclone chamber (631); the connecting section (621) comprises a hot channel (6211) and a cold channel (6212); the hot channel (6211) is tangentially connected to the upper part of the cyclone chamber (631); and the cold channel (6212) is tangentially connected to the middle part of the cyclone chamber (631).

5. A low-temperature recycling type high-efficiency energy-saving grain dryer according to claim 4, characterized in that: The upper portion of the ascending pipe (633) is connected to the heating section (622); and the air inlet channel (61) is connected to the upper portion of the swirl chamber (631).

6. A low-temperature recycling type high-efficiency energy-saving grain dryer according to claim 5, characterized in that: The adsorption and filtering mechanism (64) comprises an activated carbon layer (641) and a cyclone plate (642); the activated carbon layer (641) is arranged in the riser (633); and the cyclone plate (642) is arranged below the activated carbon layer (641).

7. The low-temperature recycling type high-efficiency energy-saving grain dryer according to claim 3 is characterized by: The air inlet channel (61) comprises a recovery section (611) and an output section (612); one end of the recovery section (611) is connected to the housing (51), and the other end is connected to the heat exchanger (55); one end of the output section (612) is connected to the heat exchanger (55), and the other end is connected to the air inlet system (3).

8. The low-temperature recycling type high-efficiency energy-saving grain dryer according to claim 7 is characterized in that: A sealed cavity (511) is provided in the shell (51); two side walls of the sealed cavity (511) are respectively connected to the outflow section (623) and the recovery section (611); and the evaporator (52) is provided in the sealed cavity (511).

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