Infrared heat pump drying machine and drying method

Abstract

The invention discloses an infrared heat pump drying machine, which comprises a drying chamber, a plurality of infrared heat pumps, a plurality of infrared heat pumps, a plurality of infrared heat pumps, a plurality of infrared heat pumps, a plurality of infrared heat pumps, a plurality of infrared heat pumps, a plurality of infrared heat pumps and a plurality of infrared heat pumps, and is characterized in that the infrared heat pumps are arranged on the infrared heat pumps; the heat pump drying system comprises a heat pump drying outer box, an evaporator, a compressor and a condenser, the evaporator, the compressor and the condenser are arranged in the heat pump drying outer box, humid air in the drying chamber enters the heat pump drying outer box through an air outlet and an air return pipe, and the humid air is conveyed back to the drying chamber through an air supply pipe and an air supply outlet after being dried, dehydrated and heated by a heat pump; and the infrared drying system comprises a pair of infrared drying racks and a pair of carbon fiber infrared radiant panel groups. The invention further discloses an infrared heat pump drying method. Infrared drying and heat pump drying can be combined for use, the rapid heating characteristic of infrared rays can be utilized, heat can be recycled through a heat pump system, and the dual purposes of energy conservation and high efficiency are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of drying Chinese medicinal materials, and more specifically, to an infrared heat pump drying machine and a drying method. Background Art

[0002] Licorice is an extremely important medicinal material in the field of traditional Chinese medicine. It has many medicinal effects such as clearing away heat and detoxifying, moistening the lungs and relieving cough. However, if licorice is not properly dried after picking, it is very easy to become moldy and deteriorate due to improper storage conditions. This will not only seriously affect the medicinal quality of licorice, seriously threaten human health and life safety, but also cause a large amount of medicinal material waste, thereby increasing the planting cost of licorice. Due to the lack of theoretical research and practical application in the drying process of raw material processing, the productivity of a series of semi-finished products such as licorice slices is insufficient. Its drying and initial processing is an urgent problem to be solved, especially the storage, processing and transportation of dry products have very high requirements on the drying quality of licorice. Therefore, it is particularly important to explore a drying equipment and method that is efficient, environmentally friendly and can guarantee the quality of licorice.

[0003] At present, the traditional method of drying licorice is mainly natural drying. After being harvested from the field, it is spread on a large drying field. It not only occupies a large area and wastes space resources, but also takes a long drying cycle. In case of rainy weather, there will be a large area of ​​mildew. At the same time, the effective ingredients in licorice dried under natural conditions are seriously lost, the sanitary environment cannot be guaranteed, and it is easy to be contaminated by insects and flies. The new drying technology mainly includes infrared drying, heat pump drying, vacuum freeze drying, microwave vacuum drying, etc., all of which have their own advantages. Infrared drying mainly uses infrared radiation to heat licorice to evaporate its internal moisture quickly. Heat pump drying mainly recovers and reuses the heat generated during the drying process through the heat pump system, thereby saving energy. However, in practical applications, we found that these two methods each have some limitations. Although infrared drying has a fast heating speed, it may cause the surface temperature of licorice to be too high, affecting the quality of the medicinal materials. Although heat pump drying is energy-saving, the drying speed is relatively slow. How to overcome the defects of a single drying method, combine the advantages of the two drying methods to complement each other for joint drying, lay the licorice on a multi-layer drying tray for synchronous drying to ensure the quality and drying efficiency of the licorice is the technical problem that this application aims to solve. Summary of the invention

[0004] The invention provides an infrared heat pump dryer and a drying method, which can combine infrared drying with heat pump drying, can utilize the rapid heating characteristics of infrared rays, and can also recover heat through a heat pump system, thereby achieving the dual goals of energy saving and high efficiency.

[0005] In order to achieve these purposes and other advantages according to the present invention, an infrared heat pump dryer is provided, comprising: A drying chamber, wherein a floor scale is provided inside, a drying rack is provided above the floor scale, the drying rack is provided with multiple layers of drying plates for placing materials, and the drying chamber is provided with air supply ports and air exhaust ports; The heat pump drying system comprises a heat pump drying outer box and an evaporator, a compressor and a condenser arranged in the heat pump drying outer box. The humid air in the drying room enters the heat pump drying outer box from the exhaust port through the return air duct, and is transported back to the drying room from the air supply port through the air supply pipe after being dehydrated and heated by the heat pump drying. The low-temperature and low-pressure refrigerant gas is compressed by the compressor into a high-temperature and high-pressure refrigerant gas, which enters the condenser and is condensed into a refrigerant liquid, and then enters the evaporator and evaporates into a refrigerant gas. An infrared drying system comprises a pair of infrared drying racks and a pair of carbon fiber infrared radiation panel groups. The pair of infrared drying racks are mounted on both sides of the drying racks and are located outside the floor scale. One infrared drying rack is equipped with a carbon fiber infrared radiation panel group through a lifting structure. One carbon fiber infrared radiation panel group comprises a plurality of carbon fiber infrared radiation panels. The plurality of carbon fiber infrared radiation panels can rotate synchronously relative to the infrared drying racks. A carbon fiber infrared radiation panel is located below a layer of drying plates. Any pair of carbon fiber infrared radiation panels forms a gap.

[0006] Preferably, an air supply chamber is provided outside the drying chamber, and a wind box of the air supply chamber is connected to the air supply pipe; The air supply outlet comprises a first air supply outlet and a plurality of second air supply outlets, wherein the first air supply outlet is located at the top of the drying chamber and directly above the lifting frame, and the plurality of second air supply outlets are located on a side wall of the drying chamber, and the plurality of second air supply outlets are connected to the air supply pipe through the air box of the air supply chamber, and the first air supply outlet and the second air supply outlet are respectively provided with a first air supply fan and a second air supply fan; The exhaust outlet includes a first exhaust outlet and a second exhaust outlet. The first exhaust outlet and the second exhaust outlet are located at the upper and lower parts of another side wall of the drying chamber and are not on the same side wall as the multiple second air supply outlets. The first exhaust outlet and the second exhaust outlet are respectively provided with an upper dehumidification fan and a lower dehumidification fan.

[0007] Preferably, the wind box of the air supply chamber is connected one by one with the multiple second air supply outlets through multiple air outlet pipe sections with reduced diameters, and a ceramic heating plate is provided inside the wind box on the opposite side of the multiple air outlet pipe sections with reduced diameters.

[0008] Preferably, the infrared drying rack includes an upper rack body and a lower rack body. The upper rack body is a U-shaped rack body. A carbon fiber infrared radiation panel group is arranged between a pair of vertical parts of the upper rack body. A pair of long strip-shaped notches are further arranged at the lower parts of the pair of vertical parts of the upper rack body. The lower rack body is an L-shaped rack body. The horizontal part of the lower rack body is fixed to the ground through anchor bolts. The vertical part of the lower rack body is located outside the upper rack body. A vertical guide groove is arranged on the inner side of the vertical part of the lower rack body. A guide block is arranged on the outside of the upper rack body. The guide groove is matched with the guide block. The lower rack body is provided with a bearing seat. A pair of horizontal rotating shafts are horizontally penetrated through the bearing seat. The two ends of the horizontal rotating shafts extend to the pair of long strip-shaped notches. One of the horizontal rotating shafts rotates under the drive of a first motor; The lifting structure includes two lifting components. One lifting component is arranged in one long strip-shaped notch. The lifting component includes a pair of racks and a pair of gears. The pair of racks are arranged on the opposite side walls of one long strip-shaped notch. The pair of gears are arranged at the same end of the pair of horizontal rotating shafts. The pair of gears are meshed with each other and are respectively meshed with the pair of racks.

[0009] Preferably, the upper rack body is provided with a plurality of horizontal rollers through a plurality of pairs of bearings. A carbon fiber infrared radiation panel is arranged on one horizontal roller. One of the horizontal rollers rotates under the drive of a second motor. The plurality of horizontal rollers are linked through a linkage structure.

[0010] An infrared heat pump drying method, applying the infrared heat pump dryer, includes: Step 1: Move the drying rack above the weighing scale, and move a pair of infrared drying racks to both sides of the drying rack and outside the weighing scale; Step 2: Lay the materials on each layer of drying trays, attach at least one first temperature sensor to the surface of the materials, bury at least one second temperature sensor inside the materials, weigh, and calculate the initial weight of the materials; Step 3: Adjust the height of the pair of carbon fiber infrared radiation panel groups to make them close to the upper drying tray, start the infrared drying system for radiation heating until the difference between the average temperature detected by the first temperature sensor and the average temperature detected by the second temperature sensor is less than the first temperature difference threshold; Step 4: Turn off the infrared drying system, adjust the height of the pair of carbon fiber infrared radiation panel groups to make them in the middle of the upper and lower drying trays, start the second air supply fan of the heat pump drying system for conduction heating, start the upper moisture exhaust fan and the lower moisture exhaust fan of the heat pump drying system until the difference between the average temperature detected by the first temperature sensor and the average temperature detected by the second temperature sensor is less than the second temperature difference threshold, and the second temperature difference threshold is lower than the first temperature difference threshold; Step 5: Start the infrared drying system for radiation heating, and at the same time start the first air supply fan and the second air supply fan of the heat pump drying system for conduction heating, turn off the upper dehumidification fan and the lower dehumidification fan of the heat pump drying system, weigh, and calculate the real-time weight of the material until the moisture content of the material is reduced to the target moisture content threshold.

[0011] Preferably, when the time t taken for the difference between the average temperature detected by the first temperature sensor and the average temperature detected by the second temperature sensor to be less than the second temperature difference threshold is greater than a preset time t0, step four further includes: Adjust the angle of a pair of carbon fiber infrared radiation panels so that one group of carbon fiber infrared radiation panels rotates upward by 40-60 degrees, and the other group of carbon fiber infrared radiation panels rotates downward by 40-60 degrees, switch and start the first air supply fan of the heat pump drying system for conduction heating, continue to start the upper dehumidification fan and the lower dehumidification fan of the heat pump drying system, weigh and calculate the real-time weight of the material until the moisture content of the material is reduced to the first moisture content threshold; Adjust the angle of a pair of carbon fiber infrared radiation panels, rotate one group of carbon fiber infrared radiation panels downward by 40-60 degrees, rotate one group of carbon fiber infrared radiation panels upward by 40-60 degrees, continue to start the first air supply fan of the heat pump drying system for conduction heating, continue to start the upper dehumidification fan and the lower dehumidification fan of the heat pump drying system, weigh and calculate the real-time weight of the material until the moisture content of the material is reduced to a second moisture content threshold value, the second moisture content threshold value is higher than the target moisture content threshold value, and the second moisture content threshold value is lower than the first moisture content threshold value; Adjust the angle of a pair of carbon fiber infrared radiation panels to reset them to horizontal, adjust the height of a pair of carbon fiber infrared radiation panels to make them located between the upper and lower drying plates, and proceed to step five.

[0012] The present invention has at least the following beneficial effects: First, the infrared heat pump drying machine of the present invention combines infrared drying with heat pump drying, which can not only utilize the rapid heating characteristics of infrared rays, but also recover heat through the heat pump system, achieving the dual goals of energy saving and high efficiency. The infrared heat pump drying method of the present invention ensures the quality and drying efficiency of licorice, reduces the loss of effective ingredients, avoids the loss of heat-sensitive ingredients, and solves the problems of poor rehydration of materials, large nutritional losses, unsatisfactory taste, color, and flavor, and reduces the degree of oxidative denaturation of ingredients.

[0013] Second, the drying room of the present invention is the main place for combined drying. A floor scale is set in the drying room to weigh the drying rack and the material, and then the moisture content of the material is calculated to measure the degree of dryness of the material. The drying rack can be a general frame structure, and the installation method of the drying plate is detachable, preferably hanging, rigging, etc. The drying plate is a mesh structure, which is convenient for simultaneous heat transfer from top to bottom and from bottom to top.

[0014] Third, the heat pump drying system of the present invention is used to heat the air entering the drying chamber. Specifically, the compressor compresses the low-temperature and low-pressure refrigerant gas into a high-temperature and high-pressure refrigerant gas, which then enters the condenser. Through a series of heat exchange processes, the heat it carries is transferred to the external environment, and the refrigerant gas itself is gradually cooled and condensed into a refrigerant liquid, which enters the evaporator and evaporates into a refrigerant gas, thereby realizing effective heat transfer. The evaporator absorbs heat in the air and part of the waste heat discharged during the drying process, and the condenser preheats the air entering the drying chamber by releasing a large amount of heat.

[0015] Fourth, the infrared drying system of the present invention is used to heat the material on the drying plate. The number of infrared drying racks is a pair, and the two sides of the drying racks are symmetrically arranged. The weight that does not contact the drying rack is not included in the weighing weight. The infrared drying rack is mainly used to install a carbon fiber infrared radiation panel group. After a pair of carbon fiber infrared radiation panel groups are assembled, each pair of carbon fiber infrared radiation panels is located under each layer of drying plate to achieve heat radiation from bottom to top to the drying plate. The carbon fiber infrared radiation panel group can be raised and lowered to adjust the height relative to the infrared drying rack to adjust the distance from the upper drying plate. The lifting structure can be a power device such as an oil cylinder and a hydraulic lifting frame. The carbon fiber infrared radiation panel group can also be rotated and adjusted relative to the infrared drying rack to adjust the angle with the upper drying plate. A group of carbon fiber infrared radiation panels rotate synchronously and can be driven by belts in pairs, gear meshing transmission and other power devices.

[0016] Fifth, the present invention sets an air supply chamber outside the drying chamber to divert and guide the hot air. The first air supply port and the first air supply fan realize hot air supply from top to bottom, the second air supply port and the second air supply fan realize horizontal hot air supply, and the first exhaust port and the second exhaust port realize convection hot air drying, which reduces energy consumption and reduces nutrient loss. By setting a plurality of reduced diameter air outlet pipe sections on the bellows, the wind speed of the air outlet is increased, and by setting a ceramic heating plate, heat preservation and heating are further realized, hot air circulation is realized, and the drying time is shortened.

[0017] Sixth, the present invention designs the infrared drying rack as an upper frame and a lower frame, and the upper frame and the lower frame are a dynamic frame and a static frame that cooperate with each other. In order to improve the stable lifting of the upper frame and the lower frame, in addition to the lifting structure, an auxiliary support structure, such as an elastic member, a power member, etc., can be set between the upper frame and the lower frame. The upper frame is provided with a long strip notch for forming a connection with the lower frame, that is, the meshing of the rack and the gear to achieve power transmission, so that the upper frame is stably lifted and lowered at a uniform speed compared with the lower frame. The horizontal roller is rotatably installed on the upper frame through the bearing, and the carbon fiber infrared radiation plate is rotated by rotating the horizontal roller. The horizontal rollers can be linked by installing a gear assembly. For example, two adjacent horizontal rollers are respectively installed with roller gears of the same specification. The two roller gears are meshed with the driving gear at the same time, and the driving gear is driven to realize the rotation of a carbon fiber infrared radiation plate group. The horizontal rollers can also be linked by installing a belt assembly. For example, two adjacent horizontal rollers are driven by a belt to drive a horizontal roller to realize the rotation of a carbon fiber infrared radiation plate group.

[0018] Seventh, the drying method of the present invention can solve the problem of slow initial heating rate in heat pump drying, and can also solve the problem of too high surface temperature and difficulty in moisture loss in infrared drying. First, start the infrared drying system for radiation heating, which can use the penetrating power of infrared radiation to make the water molecules in the material tissue form a motion effect to achieve water evaporation, and the temperature difference is quickly reduced. Then turn off the infrared drying system, start the heat pump drying system, use the second air supply fan for conduction heating, and start the upper and lower dehumidification fans at the same time to recover the heat of the wet air, which greatly reduces energy consumption and forms convection hot air drying, and the temperature difference is further reduced.

[0019] Eighth, when the laying thickness is large or the stacking density is large, the heat pump drying system is further started, and the first air supply fan is used for conduction heating. At the same time, the upper dehumidification fan and the lower dehumidification fan are started, and the angle of a pair of carbon fiber infrared radiation panels is adjusted. The angle of a pair of carbon fiber infrared radiation panels is adjusted again to form different tortuous paths. There is a humidity gradient between the moisture content of the material and the surrounding air. The concentration diffusion power is used to achieve uniform drying of the material surface, which improves the efficiency of heat pump drying. Under the premise of reducing energy consumption, the moisture content is promoted to reduce the speed. Finally, the infrared drying system and the heat pump drying system are started at the same time, and the upper dehumidification fan and the lower dehumidification fan are turned off to increase the hot air blowing angle and internal hot air disturbance to further dehumidify and improve the drying effect.

[0020] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1A schematic plan view of an infrared heat pump dryer according to a technical solution of the present invention; Figure 2 A schematic diagram of the structure of an infrared heat pump dryer according to a technical solution of the present invention; Figure 3 A structural schematic diagram of a drying rack according to a technical solution of the present invention; Figure 4 A schematic structural diagram of an infrared drying system according to a technical solution of the present invention; Figure 5 A schematic flow chart of an infrared drying method according to a technical solution of the present invention; Figure 6 This is a photo of a dried licorice sample according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0023] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0024] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials can be obtained from commercial sources unless otherwise specified; in the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "set" should be understood in a broad sense, for example, they can be fixedly connected, set, or detachably connected, set, or connected and set in one piece. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood in specific circumstances. The orientation or position relationship indicated by the terms "lateral", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0025] like Figures 1 to 4 As shown, the present invention provides an infrared heat pump dryer, comprising: A drying chamber 1 is provided with a floor scale 2 inside, a drying rack 3 is provided above the floor scale 2, and a multi-layer drying plate 4 is provided on the drying rack 3 to place materials. The drying chamber 1 is provided with an air supply port and an air exhaust port.

[0026] The drying room 1 is the main place for combined drying. A floor scale 2 is set in the drying room 1 to weigh the drying rack 3 and the material, and then the moisture content of the material is calculated to measure the degree of drying of the material. Specifically, the weight of the drying rack 3 is w0, the initial weight of the material after being placed on the drying rack 3 is w1, and the weight of the material on the drying rack 3 after drying for a period of time is w2. The moisture content U%=(W1-W2) / (W1-W0)×100%. The drying rack 3 can be a general frame structure. The installation method of the drying plate 4 is detachable, preferably hanging, rigging, etc. The drying plate 4 is a mesh structure, which is convenient for simultaneous heat transfer from top to bottom and from bottom to top.

[0027] The heat pump drying system comprises a heat pump drying outer box 9 and an evaporator, a compressor and a condenser arranged in the heat pump drying outer box 9. The humid air in the drying chamber 1 enters the heat pump drying outer box 9 from the exhaust port through the return air duct, and is transported back to the drying chamber 1 from the air supply port through the air supply pipe after being dehydrated and heated by the heat pump drying. The low-temperature and low-pressure refrigerant gas is compressed by the compressor into a high-temperature and high-pressure refrigerant gas, enters the condenser, is condensed into a refrigerant liquid, and then enters the evaporator to evaporate into a refrigerant gas.

[0028] The heat pump drying system is used to heat the air entering the drying chamber 1. Specifically, the compressor compresses the low-temperature and low-pressure refrigerant gas into a high-temperature and high-pressure refrigerant gas. Then, the high-temperature and high-pressure refrigerant gas enters the condenser, and through a series of heat exchange processes, the heat it carries is transferred to the external environment. The refrigerant gas itself is gradually cooled and condensed into a refrigerant liquid, and then enters the evaporator to evaporate into a refrigerant gas, thereby realizing effective heat transfer. The evaporator absorbs heat in the air and part of the waste heat discharged during the drying process, and the condenser preheats the air entering the drying chamber 1 by releasing a large amount of heat.

[0029] An infrared drying system includes a pair of infrared drying racks 10 and a pair of carbon fiber infrared radiation panel groups. The pair of infrared drying racks 10 are set up on both sides of the drying rack 3 and are located outside the floor scale 2, that is, no weight is applied to the floor scale 2. One infrared drying rack 10 is equipped with a carbon fiber infrared radiation panel group through a lifting structure. One carbon fiber infrared radiation panel group includes multiple carbon fiber infrared radiation panels 11. The multiple carbon fiber infrared radiation panels 11 can rotate synchronously relative to the infrared drying rack 10. A carbon fiber infrared radiation panel 11 is located below a layer of drying tray 4. Any pair of carbon fiber infrared radiation panels 11 forms a gap.

[0030] The infrared drying system is used to heat the material on the drying plate 4. The number of infrared drying racks 10 is a pair, which are symmetrically arranged on both sides of the drying rack 3, do not contact the drying rack 3, and are not included in the weighing weight. The infrared drying rack 10 is mainly used to install a carbon fiber infrared radiation panel group. After a pair of carbon fiber infrared radiation panel groups are assembled, each pair of carbon fiber infrared radiation panels 11 is located below each layer of drying plate 4 to achieve heat radiation from bottom to top to the drying plate 4. The carbon fiber infrared radiation panel group can be raised and lowered to adjust the height relative to the infrared drying rack 3 to adjust the distance from the upper drying plate 4. The lifting structure can be a power device such as an oil cylinder and a hydraulic lifting frame. The carbon fiber infrared radiation panel group can also be rotated and adjusted relative to the infrared drying rack 3 to adjust the angle with the upper drying plate 4. A group of carbon fiber infrared radiation panels 11 rotate synchronously, which can be driven by multiple motors one by one, or can be achieved by power devices such as belt transmission in pairs, gear meshing transmission, etc.

[0031] In the above technical solution, the infrared heat pump dryer of the present invention combines infrared drying with heat pump drying, which can not only utilize the rapid heating characteristics of infrared rays, but also recover heat through the heat pump system, thereby achieving the dual goals of energy saving and high efficiency.

[0032] In another technical solution, an air supply chamber 12 is provided outside the drying chamber 1, and a wind box 13 of the air supply chamber 12 is connected to the air supply pipe; The air supply outlet includes a first air supply outlet 5 and a plurality of second air supply outlets 6, wherein the first air supply outlet 5 is located at the top of the drying chamber 1 and directly above the lifting frame, and the plurality of second air supply outlets 6 are located on a side wall of the drying chamber 1, and the plurality of second air supply outlets 6 are connected to the air supply pipe through the wind box 13 of the air supply chamber 12, and the first air supply outlet 5 and the second air supply outlet 6 are respectively provided with a first air supply fan and a second air supply fan; The exhaust outlet includes a first exhaust outlet 7 and a second exhaust outlet 8. The first exhaust outlet 7 and the second exhaust outlet 8 are located at the upper and lower parts of the other side wall of the drying chamber 1, and are not on the same side wall as the plurality of second air supply outlets 6. The first exhaust outlet 7 and the second exhaust outlet 8 are respectively provided with an upper dehumidification fan and a lower dehumidification fan.

[0033] In the above technical scheme, an air supply chamber 12 is set outside the drying chamber 1 to divert and guide the hot air. The first air supply port 5 and the first air supply fan realize hot air supply from top to bottom, the second air supply port 6 and the second air supply fan realize horizontal hot air supply, and the first exhaust port 7 and the second exhaust port 8 realize convection hot air drying, which reduces energy consumption and reduces nutrient loss.

[0034] In another technical solution, the air box 13 of the air supply chamber 12 is in one-to-one communication with a plurality of second air supply ports 6 through a plurality of reduced-diameter air outlet pipe segments, and a ceramic heating plate 14 is provided inside the air box 13 on the side opposite to the plurality of reduced-diameter air outlet pipe segments. By providing a plurality of reduced-diameter air outlet pipe segments in the air box 13, the air outlet speed is increased. By providing the ceramic heating plate 14, heat preservation and heating are further realized, the hot air circulates and flows, and the drying time is shortened.

[0035] In another technical solution, as Figure 2-3 shown (where Figure 3 in order to show the lifting structure, the vertical part of the lower frame body 16 is hidden), the infrared drying machine frame 10 includes an upper frame body 15 and a lower frame body 16. The upper frame body 15 is a U-shaped frame body, that is, a portal frame. A carbon fiber infrared radiation plate group is provided between a pair of vertical parts of the upper frame body 15. A pair of long strip-shaped notches are further provided at the lower parts of a pair of vertical parts of the upper frame body 15. The lower frame body 16 is an L-shaped frame body. The horizontal part of the lower frame body 16 is fixed to the ground through anchor bolts and has a counterweight. The vertical part of the lower frame body 16 is located outside the upper frame body 15. A vertical guide groove is provided inside the vertical part of the lower frame body 16, and a guide block is provided outside the upper frame body 15. The guide groove and the guide block cooperate to ensure the linear lifting movement of the upper frame body 15 relative to the lower frame body 16 under the traction of the lifting assembly. The lower frame body 16 is provided with a bearing seat 17, and the number of bearing seats 17 is one or more. A pair of horizontal rotating shafts 18 are arranged in parallel through the bearing seat 17. The two ends of the horizontal rotating shaft 18 extend to a pair of long strip-shaped notches, and one of the horizontal rotating shafts 18 rotates under the drive of a first motor; The lifting structure includes two lifting assemblies. One lifting assembly is arranged in one long strip-shaped notch. The lifting assembly includes a pair of racks 19 and a pair of gears 20. A pair of racks 19 are arranged on the opposite side walls of one long strip-shaped notch, and a pair of gears 20 are arranged at the same end of a pair of horizontal rotating shafts 18. The pair of gears 20 are meshed with each other and are respectively meshed with a pair of racks 19.

[0036] In the above technical solution, the infrared drying machine frame 10 is designed as an upper frame body 15 and a lower frame body 16. The upper frame body 15 and the lower frame body 16 are a moving frame body and a static frame body that cooperate with each other. In order to improve the stable lifting of the upper frame body 15 and the lower frame body 16, in addition to the lifting structure, an auxiliary support structure, such as an elastic member, a power member, etc., can be provided between the upper frame body 15 and the lower frame body 16. The upper frame body 15 is provided with a long strip-shaped notch for forming a connection with the lower frame body 16, that is, the meshing of the rack 19 and the gear 20, to realize power transmission, so that the upper frame body 15 lifts stably and evenly compared with the lower frame body 16.

[0037] In another technical solution, as Figure 2-3As shown, the upper frame 15 is provided with a plurality of horizontal rollers 21 through a plurality of pairs of bearings, a carbon fiber infrared radiation plate 11 is provided on a horizontal roller 21, one of the horizontal rollers 21 is driven by a second motor to rotate, and the plurality of horizontal rollers 21 are linked by a linkage structure. The horizontal rollers 21 are rotatably mounted on the upper frame 15 through bearings, and the carbon fiber infrared radiation plate 11 is rotated by rotating the horizontal rollers 21. The horizontal rollers 21 can be linked by installing gear components, for example, two adjacent horizontal rollers 21 are respectively installed with roller gears of the same specification, and the two roller gears are meshed with the driving gear at the same time, driving the driving gear to realize the rotation of a carbon fiber infrared radiation plate group, and the horizontal rollers 21 can also be linked by installing belt components, for example, two adjacent horizontal rollers 21 are driven by belts, and one horizontal roller 21 is driven to realize the rotation of a carbon fiber infrared radiation plate group.

[0038] like Figure 5 As shown, the infrared heat pump drying method, using the infrared heat pump dryer, comprises: Step 1: Move the drying rack 3 to above the floor scale 2, the weight of the drying rack 3 is w0, and move a pair of infrared drying racks 10 to both sides of the drying rack 3 and outside the floor scale 2; Step 2: Lay the material on each layer of drying tray 4, attach at least one first temperature sensor to the surface of the material, bury at least one second temperature sensor inside the material, weigh it, the initial weight of the material after being placed on the drying rack 3 is w1, calculate the initial weight of the material w1-w0; Step 3: If Figure 5 As shown in a, the height of a pair of carbon fiber infrared radiation panels is adjusted so that they are close to the drying plate 4 above, and the infrared drying system is started for radiation heating until the difference between the average temperature detected by the first temperature sensor and the average temperature detected by the second temperature sensor is less than the first temperature difference threshold; Step 4: If Figure 5 As shown in b, the infrared drying system is turned off, the height of a pair of carbon fiber infrared radiation panels is adjusted so that they are located between the upper and lower drying plates 4, the second air supply fan of the heat pump drying system is started for conduction heating, and the upper dehumidification fan and the lower dehumidification fan of the heat pump drying system are started until the difference between the average temperature detected by the first temperature sensor and the average temperature detected by the second temperature sensor is less than the second temperature difference threshold, and the second temperature difference threshold is lower than the first temperature difference threshold; Step 5: Start the infrared drying system for radiation heating, and start the first air supply fan and the second air supply fan of the heat pump drying system for conduction heating. Turn off the upper dehumidification fan and the lower dehumidification fan of the heat pump drying system. Weigh the material on the drying rack 3 after drying for a period of time. The weight of the material is w2. Calculate the real-time weight of the material w2-w0, and the moisture content U%=(W1-W2) / (W1-W0)×100%, until the moisture content of the material is reduced to the target threshold.

[0039] In the above technical scheme, the slow initial heating rate existing in heat pump drying can be solved, and the problem of excessive surface temperature and difficulty in moisture loss existing in infrared drying can also be solved. First, the infrared drying system is started for radiation heating, which can utilize the penetrating power of infrared radiation to make the water molecules in the material tissue form a motion effect to achieve moisture evaporation, and the temperature difference is rapidly reduced. Then the infrared drying system is turned off, and the heat pump drying system is started. The second air supply fan is used for conduction heating. At the same time, the upper and lower dehumidification fans are started to recover the heat of the humid air, which greatly reduces energy consumption and forms convection hot air drying. The temperature difference is further reduced. Finally, the infrared drying system and the heat pump drying system are started at the same time, and the upper and lower dehumidification fans are turned off to increase the hot air blowing angle and internal hot air disturbance, further dehumidify, and improve the drying effect.

[0040] In another technical solution, when the time t taken for the difference between the average temperature detected by the first temperature sensor and the average temperature detected by the second temperature sensor to be less than the second temperature difference threshold is greater than the preset time t0, step four further includes: like Figure 5 c, adjust the angle of a pair of carbon fiber infrared radiation panels so that one group of carbon fiber infrared radiation panels 11 rotates upward by 40-60 degrees, and the other group of carbon fiber infrared radiation panels 11 rotates downward by 40-60 degrees, switch and start the first air supply fan of the heat pump drying system for conduction heating, continue to start the upper dehumidification fan and the lower dehumidification fan of the heat pump drying system, weigh, and calculate the real-time weight of the material until the moisture content of the material is reduced to the first moisture content threshold; like Figure 5 d, adjust the angle of a pair of carbon fiber infrared radiation panels, so that one group of carbon fiber infrared radiation panels 11 rotates downward by 40-60 degrees, and another group of carbon fiber infrared radiation panels 11 rotates upward by 40-60 degrees, continue to start the first air supply fan of the heat pump drying system for conduction heating, continue to start the upper dehumidification fan and the lower dehumidification fan of the heat pump drying system, weigh, and calculate the real-time weight of the material until the moisture content of the material is reduced to a second moisture content threshold value, the second moisture content threshold value is higher than the target moisture content threshold value, and the second moisture content threshold value is lower than the first moisture content threshold value; like Figure 5As shown in b, adjust the angle of a pair of carbon fiber infrared radiation panels to reset them to horizontal, adjust the height of a pair of carbon fiber infrared radiation panels to make them located between the upper and lower drying plates 4, and proceed to step five.

[0041] In the above technical scheme, when t>t0, it means that the material drying speed is relatively slow and uneven, which may be due to the large laying thickness or large stacking density. Then the heat pump drying system is further started, and the first air supply fan is used for conduction heating. At the same time, the upper dehumidification fan and the lower dehumidification fan are started, and the angle of a pair of carbon fiber infrared radiation panels is adjusted. The angle of a pair of carbon fiber infrared radiation panels is adjusted again to form different tortuous paths. There is a humidity gradient between the moisture content of the material and the surrounding air. The concentration diffusion power is used to achieve uniform drying of the material surface, thereby improving the efficiency of heat pump drying and promoting the reduction rate of moisture content while reducing energy consumption.

[0042] In an application example, the drying method of the present invention is used to alternately combine infrared drying with heat pump drying. The dried licorice sample is as follows: Figure 6 Phenols and ketones are important nutrients in licorice, but they are easily thermally oxidized or degraded during the drying process, thereby reducing the nutritional quality of licorice. The effect of the drying method of the present invention on total phenols and total ketones of licorice was tested. The results showed that the total phenol content in the fresh licorice sample was 0.2198 mg RE / g dw, which means the content of total phenols per gram of dry weight sample, expressed in milligrams of quercetin equivalents; the total flavonoid content in the fresh licorice sample was 0.2756 mg RE / gdw, which means the content of total flavonoids per gram of dry weight sample, expressed in milligrams of gallic acid equivalents; the total phenol content in the dried licorice sample was 0.2104 mg RE / g dw; the total flavonoid content in the fresh licorice sample was 0.2698 mg RE / g dw. This may be because the drying time of the drying method of the present invention is very short, which ensures the quality and drying efficiency of licorice, reduces the loss of effective ingredients, avoids the loss of heat-sensitive ingredients, and well solves the problems of poor rehydration of the material, large nutritional loss, unsatisfactory taste, color, and flavor, and reduces the degree of oxidative denaturation of the ingredients.

[0043] The drying method of the present invention combines infrared drying and heat pump drying for alternating use, which greatly shortens the drying cycle for making licorice reach a safe moisture content. This is probably because ① the infrared drying system is started, the temperature is set to 45°C, far-infrared radiation with a band of 5-20 μm is generated, and heating is performed for 3 minutes, so that the deep layer and the surface layer of the licorice can form a thermal effect synchronously, ② the horizontal air supply of the heat pump drying system is started, the temperature is set to 45°C, and heating is performed for 3 minutes. The wind speed of the dehumidification fan is set to 5 m / s, so that the activity of water molecules is improved, the binding force between water molecules is weakened, and the internal chemical bonds are destroyed, ③ the vertical zigzag air supply of the heat pump drying system is started, the temperature is set to 45°C, and heating is performed for 4 minutes. The wind speed of the dehumidification fan is set to 3 m / s, so that the bound water in the cell part is converted into free water with better fluidity, the internal diffusion boundary of the material is reduced, and the mass transfer and heat transfer efficiency is enhanced, ④ the infrared drying system is started, the heat pump drying system is started, the temperature is set to 45°C, and far-infrared radiation with a band of 5-20 μm is generated, and heating is performed for 2 minutes. min, turn off the dehumidification fan. After licorice absorbs heat through heat transfer, the heat is transferred from the outside to the inside, and the moisture is transferred from the inside to the outside, gradually reaching the critical moisture content.

[0044] The number of devices and processing scales described here are used to simplify the description of the present invention. Applications, modifications and variations of the present invention will be obvious to those skilled in the art.

[0045] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. Infrared heat pump dryer, characterized in that: Comprising: A drying chamber, inside which there is a weighbridge, above the weighbridge there is a drying rack, and multiple drying trays are provided on the drying rack for placing materials. The drying chamber is provided with an air supply port and an air discharge port; A heat pump drying system, which includes a heat pump drying outer box and an evaporator, a compressor, and a condenser provided in the heat pump drying outer box. The humid air in the drying chamber enters the heat pump drying outer box through the air discharge port and the return air duct, and after being dehydrated and heated by the heat pump, it is conveyed back to the drying chamber through the air supply duct and the air supply port. The refrigerant gas at low temperature and low pressure is compressed by the compressor into a refrigerant gas at high temperature and high pressure and enters the condenser to be condensed into a refrigerant liquid, and then enters the evaporator to evaporate into a refrigerant gas; An infrared drying system, which includes a pair of infrared drying racks and a pair of carbon fiber infrared radiation panel groups. The pair of infrared drying racks are erected on both sides of the drying rack and outside the weighbridge. One infrared drying rack is installed with a carbon fiber infrared radiation panel group through a lifting structure. One carbon fiber infrared radiation panel group includes multiple carbon fiber infrared radiation panels. The multiple carbon fiber infrared radiation panels can rotate synchronously relative to the infrared drying rack. One carbon fiber infrared radiation panel is located below one layer of drying trays, and a gap is formed between any pair of carbon fiber infrared radiation panels.

2. The infrared heat pump dryer according to claim 1, characterized in that: An air supply chamber is provided outside the drying chamber, and the air box of the air supply chamber is communicated with the air supply duct; The air supply port includes a first air supply port and multiple second air supply ports. The first air supply port is located at the top of the drying chamber and directly above the lifting frame. The multiple second air supply ports are located on one side wall of the drying chamber. The multiple second air supply ports are communicated with the air supply duct through the air box of the air supply chamber. The first air supply port and the second air supply ports are respectively provided with a first air supply fan and a second air supply fan; The air discharge port includes a first air discharge port and a second air discharge port. The first air discharge port and the second air discharge port are located at the upper and lower parts of the other side wall of the drying chamber and are not on the same side wall as the multiple second air supply ports. The first air discharge port and the second air discharge port are respectively provided with an upper moisture exhaust fan and a lower moisture exhaust fan.

3. The infrared heat pump dryer according to claim 2, characterized in that: The air box of the air supply chamber is communicated with the multiple second air supply ports one by one through multiple reduced-diameter air outlet pipe sections, and a ceramic heating plate is provided inside the air box on the opposite side of the multiple reduced-diameter air outlet pipe sections.

4. The infrared heat pump dryer according to claim 3, characterized in that: The infrared drying rack includes an upper rack body and a lower rack body. The upper rack body is a U-shaped rack body. A carbon fiber infrared radiation panel group is provided between a pair of vertical parts of the upper rack body. A pair of long strip-shaped notches are also provided at the lower parts of the pair of vertical parts of the upper rack body. The lower rack body is an L-shaped rack body. The horizontal part of the lower rack body is fixed to the ground through anchor bolts. The vertical part of the lower rack body is located outside the upper rack body. A vertical guide groove is provided inside the vertical part of the lower rack body, and a guide block is provided outside the upper rack body. The guide groove and the guide block cooperate. The lower rack body is provided with a bearing seat, and a pair of horizontal rotating shafts are horizontally penetrated through the bearing seat. The two ends of the horizontal rotating shafts extend to a pair of long strip-shaped notches, and one of the horizontal rotating shafts rotates under the drive of a first motor; The lifting structure includes two lifting components, one lifting component is arranged in a long strip notch, and the lifting component includes a pair of racks and a pair of gears. The pair of racks are arranged on opposite side walls of the long strip notch, and the pair of gears are arranged at the same end of a pair of horizontal rotating shafts. The pair of gears are meshed with each other and respectively meshed with the pair of racks.

5. The infrared heat pump dryer according to claim 4, characterized in that: The upper frame is provided with a plurality of horizontal rollers through a plurality of pairs of bearings, one of the horizontal rollers is provided with a carbon fiber infrared radiation plate, one of the horizontal rollers is driven to rotate by a second motor, and the plurality of horizontal rollers are linked by a linkage structure.

6. Infrared heat pump drying method, characterized in that: The infrared heat pump dryer according to claim 5 comprises: Step 1: Move the drying rack above the floor scale, and move a pair of infrared drying racks to both sides of the drying rack and outside the floor scale; Step 2: Lay the material on each layer of drying plates, attach at least one first temperature sensor to the surface of the material, bury at least one second temperature sensor inside the material, weigh it, and calculate the initial weight of the material; Step 3: Adjust the height of a pair of carbon fiber infrared radiation panels so that they are close to the drying plate above, and start the infrared drying system for radiation heating until the difference between the average temperature detected by the first temperature sensor and the average temperature detected by the second temperature sensor is less than the first temperature difference threshold; Step 4: turn off the infrared drying system, adjust the height of a pair of carbon fiber infrared radiation panels so that they are located between the upper and lower drying plates, start the second air supply fan of the heat pump drying system for conduction heating, and start the upper dehumidification fan and the lower dehumidification fan of the heat pump drying system until the difference between the average temperature detected by the first temperature sensor and the average temperature detected by the second temperature sensor is less than the second temperature difference threshold, and the second temperature difference threshold is lower than the first temperature difference threshold; Step 5: Start the infrared drying system for radiation heating, and at the same time start the first air supply fan and the second air supply fan of the heat pump drying system for conduction heating, turn off the upper dehumidification fan and the lower dehumidification fan of the heat pump drying system, weigh, and calculate the real-time weight of the material until the moisture content of the material is reduced to the target moisture content threshold.

7. The infrared heat pump drying method according to claim 6, characterized in that: When the time t taken for the difference between the average temperature detected by the first temperature sensor and the average temperature detected by the second temperature sensor to be less than the second temperature difference threshold is greater than the preset time t0, step four further includes: Adjust the angle of a pair of carbon fiber infrared radiation panels so that one group of carbon fiber infrared radiation panels rotates upward by 40-60 degrees, and the other group of carbon fiber infrared radiation panels rotates downward by 40-60 degrees, switch and start the first air supply fan of the heat pump drying system for conduction heating, continue to start the upper dehumidification fan and the lower dehumidification fan of the heat pump drying system, weigh and calculate the real-time weight of the material until the moisture content of the material is reduced to the first moisture content threshold; Adjust the angle of a pair of carbon fiber infrared radiation panels, rotate one group of carbon fiber infrared radiation panels downward by 40-60 degrees, rotate one group of carbon fiber infrared radiation panels upward by 40-60 degrees, continue to start the first air supply fan of the heat pump drying system for conduction heating, continue to start the upper dehumidification fan and the lower dehumidification fan of the heat pump drying system, weigh and calculate the real-time weight of the material until the moisture content of the material is reduced to a second moisture content threshold value, the second moisture content threshold value is higher than the target moisture content threshold value, and the second moisture content threshold value is lower than the first moisture content threshold value; Adjust the angle of a pair of carbon fiber infrared radiation panels to reset them to horizontal, adjust the height of a pair of carbon fiber infrared radiation panels to make them located between the upper and lower drying plates, and proceed to step five.

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