Material drying, moisture increasing and flavoring equipment
By combining an air-source heat pump and a spray device, and utilizing waste gas heat and moisture recovery technology, the problems of high energy consumption and low quality in the rehydration process of leafy agricultural products and Chinese medicinal herbs after drying are solved, achieving efficient and energy-saving rehydration and aroma enhancement effects.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HUANGSHAN XINGNONG ZHONGJU DRYING EQUIP MFG CO LTD
- Filing Date
- 2025-06-26
- Publication Date
- 2026-06-02
AI Technical Summary
Existing methods for rehydrating dried leafy agricultural products and Chinese medicinal herbs are limited by climate conditions and cannot be automatically controlled. Furthermore, traditional water-based rehydration methods are energy-intensive and can reduce product quality and taste.
The system employs an air-source heat pump and a spray device. It recovers heat and moisture from the exhaust gas during the drying process through a heat exchange core and a finned evaporator. The condensate is used for rehumidification, and the spray device sprays fragrance components from the condensate to enhance the aroma of the materials. Combined with a liquid concentration device, the concentration of the condensate is increased, achieving efficient and energy-saving rehumidification.
It achieves a highly efficient and energy-saving rehumidification process, enhances the aroma and quality of materials, solves the problems of high energy consumption and low quality of traditional rehumidification methods, has wider applicability, and produces better product quality.
Smart Images
Figure CN224316612U_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of air-source heat pump drying technology, and more specifically, to a material drying, rehydration, and aroma-enhancing device. Background Technology
[0002] Currently, leafy agricultural products (including bamboo leaves), flowers, tobacco leaves, and traditional Chinese medicinal materials such as ginseng and wolfberry generally have very low moisture content after drying, making them extremely fragile and severely reducing product quality. Therefore, leafy agricultural products and traditional Chinese medicinal materials must undergo rehydration treatment in the later stages of drying to soften the leaves slightly, thereby ensuring the quality of the leafy agricultural products and the uniformity of internal moisture in the traditional Chinese medicinal materials, and preventing them from becoming brittle due to excessive dryness.
[0003] The current method of rehumidification after drying is natural rehumidification, which involves opening the drying chamber after the product has been dried to allow the product to absorb moisture from the outside air, thus achieving the purpose of rehumidification. This method is not limited by the location and is convenient and labor-saving. However, this method is severely limited by local climate conditions, cannot be automatically controlled, and cannot achieve a rapid and uniform rehumidification effect, thereby reducing the quality of the product.
[0004] In the prior art, such as patent ZL201620477518.9, an automatic humidification and rehumidification system for drying mentions adding a spray device and a heating device in the drying chamber to improve the drying quality of tobacco leaves, save drying time, and reduce drying costs.
[0005] However, the above-mentioned patent has obvious shortcomings. Although using tap water and heating devices to provide hot water can quickly rehydrate, it has problems such as high heating energy consumption, reduced or diluted taste of materials and loss of the quality of the rehydrated water source. Summary of the Invention
[0006] In view of the problems existing in the prior art, the purpose of this invention is to solve the problem of waste heat and waste gas in drying rooms and to make comprehensive utilization of them, so as to provide an energy-saving and aroma-enhancing material drying and rehumidification equipment.
[0007] To solve the above problems, the present invention adopts the following technical solution: a material drying, rehydration, and aroma-enhancing device, comprising a dryer and a spraying device. The dryer includes an air-source heat pump main unit and a drying oven detachably installed on one or both sides of the air-source heat pump main unit. The air-source heat pump main unit includes a frame and a heat exchanger, a draft fan, a heat pump, a liquid receiver, an expansion valve, a drying filter, a finned evaporator, and an electric heater mounted on the frame. The finned evaporator is located in an exhaust duct at the top of the dryer. The heat exchanger is located above the electric heater. The draft fan is installed on the lower surface of the heat exchanger with the airflow direction being from top to bottom. Below, the heat exchanger, the exhaust fan, and the electric heater form a heating chamber via a frame and partition. The nozzle of the spray device is located below the electric heater. A heat exchange core is located at the upper part of the oven where it connects to the heating chamber. The heat exchange core is composed of intersecting air ducts spaced apart. The longitudinal air ducts form the air inlet pipe of the dryer and connect to the heating chamber, while the transverse air ducts form the air outlet pipe and connect to the exhaust pipe of the finned evaporator. The air ducts are made of thermally conductive metal material. A liquid collection tank is located below the finned evaporator and the heat exchange core. The liquid collection tank is connected to a water tank via a drain pipe. The water tank is connected to the spray device.
[0008] Furthermore, the water tank is connected to a liquid concentration device, which is connected to the spray device.
[0009] Furthermore, a guide plate is provided at the bottom of the heating host below the electric heater.
[0010] Furthermore, an exhaust fan is installed inside the exhaust duct.
[0011] Furthermore, the water tank is equipped with a stirring device.
[0012] Furthermore, the spray device has multiple micron-sized nozzles arranged in a matrix and extended through pipes at the bottom of the oven.
[0013] Furthermore, the liquid concentration device is a heated evaporator concentrator.
[0014] Compared with the prior art, the present invention has the following advantages:
[0015] (1) During the material drying process, the heat exchange core is designed to use the high-temperature exhaust gas discharged from the oven to heat the outside air entering the heating chamber of the dryer in the first stage, thereby achieving the first stage of heat recovery. Here, the heat exchange core will generate a small amount of high-temperature moisture that condenses upon cooling to form condensate. This part of the condensate is collected in the water tank for later use.
[0016] (2) During the material drying process, the low-temperature finned evaporator of the air energy absorbs heat from the high-temperature and high-humidity exhaust gas discharged from the heat exchange core, and the heat recovered by this part is transferred to the heat exchanger through the air energy system to heat the air entering the heating chamber in the second stage. At the same time, the finned evaporator realizes the second stage of heat recovery. The low-temperature finned evaporator will condense a large amount of condensate, and this part of the condensate is collected in the water tank for later use.
[0017] (3) During the material rehydration process, the mist droplets sprayed by the spraying device are condensate. The condensate contains a large amount of the fragrance components and essence of the material itself. This part of the fragrance and essence is absorbed by the dried material through the mist droplets to achieve the purpose of enhancing fragrance.
[0018] (4) During the material drying process, condensate is continuously collected, and the condensate can be concentrated simultaneously. During the drying process of fresh materials, the high temperature and high humidity exhaust gas is cooled twice through the heat exchange core and finned evaporator, which can achieve more than 95% heat energy recovery and reuse. At the same time, the moisture can also be condensed and recovered at more than 50% during the drying process. Through multiple experiments, the applicant found that the amount of condensate used during the rehydration process accounts for 40-50% of the total condensate. Therefore, by using a concentration device, the total amount of recovered condensate is concentrated to 50% before spray rehydration, which greatly improves the aroma enhancement effect.
[0019] (5) Compared with the previous generation of cascade air-source heat pump ovens of our company, this dryer has the advantage of unlimited heating temperature. The original equipment used an auxiliary heat exchanger to preheat the outside air entering the main heating chamber. Most of the high-temperature and high-humidity exhaust gas in the dryer was recycled into the main heating chamber after passing through the finned evaporator. Although this saved electricity, the upper limit of the condenser temperature of the air-source heat pump heating system itself is about 80°C in high-temperature environments. If the electric heater heats the air to more than 100°C, the air-source heating system will not be able to work normally in this environment, which will limit the drying of certain agricultural products. This invention has made a breakthrough in solving the problem of unusable equipment. Through two stages of heat recovery—the heat exchange core and the finned evaporator—it achieves a heat recovery rate of over 95% and completely discharges all the high-temperature and high-humidity exhaust gas from the oven. The temperature of the air entering the air source heat exchanger after the initial heating by the heat exchange core will not affect the normal operation of the air source system. After the second stage of heating by the air source heat exchanger to below 80°C, it undergoes a third stage of heating by the electric heater below, which can heat the air to 100°C-150°C or even higher, thus improving the practicality and applicability of the dryer.
[0020] (6) Traditional water sources (usually tap water) typically contain mineral salts such as calcium and magnesium (i.e., scale). After being sprayed onto the surface of leaves or Chinese medicinal materials with water mist, calcium salts evaporate and crystallize, which may affect the quality of the product. This invention uses condensate instead of traditional water sources, perfectly solving the above problems. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the invention.
[0022] Figure 2 A schematic diagram of the heat exchange core structure for the invention;
[0023] Figure 3 This is a schematic diagram of the structure of the invention of a double-sided drying oven.
[0024] Explanation of the labels in the diagram:
[0025] 1. Dryer; 2. Spraying device; 4. Heating chamber; 5. Heat exchange core; 6. Water tank; 7. Liquid concentration device; 11. Air source heat pump main unit; 12. Drying oven; 111. Frame; 21. Nozzle; 31. Heat exchanger; 32. Drainage fan; 33. Heat pump; 34. Liquid receiver; 35. Expansion valve; 36. Drying filter; 37. Finned evaporator; 38. Electric heater; 51. Air duct; 511. Air inlet pipe; 512. Air outlet pipe; 61. Stirring device. Detailed Implementation
[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention; Example
[0027] like Figure 1 and 2As shown, the material drying, rehumidification, and aroma-enhancing equipment of this application includes a dryer 1 and a spraying device 2. The dryer includes an air-source heat pump main unit 11 and a drying oven 12 detachably installed on one or both sides of the air-source heat pump main unit 11. The air-source heat pump main unit 11 includes a frame 111 and a heat exchanger 31, a duct fan 32, a heat pump 33, a liquid receiver 34, an expansion valve 35, a drying filter 36, a finned evaporator 37, and an electric heater 38, all mounted on the frame 111. The finned evaporator 37 is located in the exhaust duct 13 at the top of the dryer. The heat exchanger 31 is located above the electric heater 38. The duct fan 32 is installed on the lower surface (or upper surface) of the heat exchanger, with the airflow direction from top to bottom. The heat exchanger 31, the induced draft fan 32, and the electric heater 38 are connected by a frame 111 and a partition to form a heating chamber 4. The nozzle 21 of the spray device 2 is located below the electric heater 38. A heat exchange core 5 is provided at the upper part of the oven 12 where it connects to the heating chamber 4. The heat exchange core 5 is composed of intersecting air ducts 51 arranged at intervals. The longitudinal air ducts form the air inlet pipe 511 of the dryer and are connected to the heating chamber 4. The transverse air ducts form the air outlet pipe 512 and are connected to the exhaust pipe 13 where the finned evaporator 37 is located. The air ducts 51 are made of thermally conductive metal material. A liquid collection tank is provided below the heat exchanger 31 and the heat exchange core 5. The liquid collection tank is connected to a water tank 6 through a drain pipe. The water tank 6 is connected to the spray device 2.
[0028] The air source heating system and other technologies in this equipment can refer to the relevant content of our invention patent "A Cascade Air Source Heating Main Unit and Drying Equipment and Its Application" (Patent No. ZL202211311546.X). Based on that invention patent, the auxiliary heat exchanger is removed, and copper pipes are used to sequentially connect the heat pump 33, heat exchanger 31, dryer filter 36, liquid receiver 34, expansion valve 35, and finned evaporator 37, and then connect them back to the heat pump 33 to form a loop. The heating air duct is also redesigned so that all high-temperature and high-humidity exhaust gas is discharged from the dryer after heat recovery and moisture recovery, and all fresh air from the outside is replenished into the dryer. This overcomes the problem of limited operation of the air source heating system caused by the circulation of high-temperature exhaust gas in the dryer and only the replenishment of a small amount of fresh air in the original patent technology.
[0029] The air duct design of the single-sided drying oven in this application is as follows: fresh air from the outside enters the heating chamber through the air inlet pipe of the heat exchange core via the induced draft fan in the heating chamber and flows from top to bottom through the drying oven. The air duct in the drying oven flows from bottom to top, and then enters the exhaust duct of the dryer through the exhaust duct of the heat exchange core. After passing through the finned evaporator in the exhaust duct, it is discharged from the dryer.
[0030] like Figure 3As shown, the air duct design of the double-sided drying oven in this application refers to the single-sided design described above. Two heat exchange cores, finned evaporators, and exhaust pipes are symmetrically arranged (the two sets of exhaust pipes can be combined into one, and the finned evaporator can be placed in the main exhaust pipe). They are symmetrically arranged above the heating host. The nozzles of the spray device are symmetrically arranged inside the drying oven. The heat pump 33, drying filter 36, liquid receiver 34, expansion valve 35, etc. of the air source heating host can be adjusted and arranged at the rear of the entire dryer, located outside the rear side wall of the heating chamber 4.
[0031] This application includes a liquid concentration device 7 in the water tank 6, which is connected to the spray device 2. The liquid concentration device 7 is a heated evaporator concentrator. Through numerous experiments, the drying equipment of this application achieves a moisture recovery rate of over 50% and a heat recovery rate of up to 95% in the condensate collected after two stages of condensation recovery (heat exchange core and finned evaporator) when drying fresh leaves (fresh materials). The heat recovery rate is high at temperatures below 90℃ and reaches over 76% at temperatures above 100℃. The total amount of recovered condensate typically accounts for about 20% of the amount used in the subsequent rehydration process. Therefore, concentrating the collected condensate to increase the concentration of aromatic substances before rehydrating it back into the leaves helps to significantly enhance the aroma. For example, with reed leaves, the dry-to-wet ratio is approximately 4:10 (10 kg of fresh leaves yields 4 kg of dried leaves). During the drying process, most of the aroma of the reed leaves, except for some that dissipates, remains in the condensate. Concentrating this condensate and allowing it to reabsorb moisture into the leaves enhances their aroma and quality. This, in turn, enhances the aroma of zongzi (sticky rice dumplings) and improves the product's market competitiveness. In experiments, drying 100 kg of reed leaves yielded approximately 30 kg of condensate (60 kg of moisture evaporated during drying). The amount of condensate used for spraying during the rehydration process is typically 10-14 kg. Using a liquid concentration device to concentrate the 30 kg of condensate to 14 kg before spraying significantly increases the aroma enhancement. The concentration device can be either pressure filtration or heating concentration. Since the equipment in this invention operates under power, a smaller heating concentration method and device are used. During concentration, water evaporates while retaining the aromatic and essential substances in the water.
[0032] The bottom of the heating unit below the electric heater 38 is provided with a guide plate 39. The guide plate 39 can straighten the airflow and reduce the turbulence caused by hot air impacting the bottom plate of the heating chamber. Furthermore, baffles can be evenly arranged on the guide plate. After the airflow is straightened by the baffles, it changes direction and enters the oven 12 evenly.
[0033] An exhaust fan 131 is installed inside the exhaust duct 13. The exhaust fan provides power for exhaust, reducing the load on the duct fan.
[0034] The water tank 6 is equipped with a stirring device 61. The stirring device in the water tank continuously stirs the liquid, which can ensure that the fragrance substances or essence in the condensate are fully dissolved in the water, preventing the essence from being separated and floating on the surface of the water and unable to enter the concentration device, thus ensuring that the recovered essence is fully utilized in the subsequent process.
[0035] The spray device 2 has multiple micron-sized nozzles arranged in a matrix at the bottom of the oven via pipes. The matrix arrangement of the micron-sized nozzles at the bottom of the oven allows the micron-sized droplets to flow upwards through the material, effectively re-moistening it.
[0036] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concepts, should be covered within the scope of protection of the present invention.
Claims
1. A material drying, rehydration, and aroma-enhancing device, characterized in that: The system includes a dryer and a spraying device. The dryer comprises an air-source heat pump main unit and a drying oven detachably mounted to one or both sides of the air-source heat pump main unit. The air-source heat pump main unit includes a frame and a heat exchanger, a duct fan, a heat pump, a liquid receiver, an expansion valve, a drying filter, a finned evaporator, and an electric heater mounted on the frame. The finned evaporator is located in an exhaust duct at the top of the dryer. The heat exchanger is located above the electric heater. The duct fan is mounted on the lower surface of the heat exchanger with the airflow direction from top to bottom. The heater forms a heating chamber via a frame and partitions. The nozzle of the spray device is located below the electric heater. A heat exchange core is installed at the upper part of the oven where it connects to the heating chamber. The heat exchange core is composed of intersecting air ducts spaced apart. The longitudinal air ducts form the air inlet pipe of the dryer and connect to the heating chamber, while the transverse air ducts form the air outlet pipe and connect to the exhaust pipe of the finned evaporator. The air ducts are made of thermally conductive metal. A liquid collection tank is located below the finned evaporator and the heat exchange core. The liquid collection tank is connected to a water tank via a drain pipe. The water tank is connected to the spray device.
2. The material drying, rehydration, and aroma-enhancing equipment as described in claim 1, characterized in that: The water tank is connected to a liquid concentration device, which is connected to the spray device.
3. The material drying, rehydration, and aroma-enhancing equipment as described in claim 1, characterized in that: A guide plate is provided at the bottom of the heating unit below the electric heater.
4. The material drying, rehydration, and aroma-enhancing equipment as described in claim 1, characterized in that: An exhaust fan is installed inside the exhaust duct.
5. The material drying, rehydration, and aroma-enhancing equipment as described in claim 1, characterized in that: The water tank is equipped with a stirring device.
6. The material drying, rehydration, and aroma-enhancing equipment as described in claim 1, characterized in that: The spray device consists of multiple micron-sized nozzles arranged in a matrix, which are extended through pipes and positioned at the bottom of the oven.
7. The material drying, rehydration, and aroma-enhancing equipment as described in claim 2, characterized in that: The liquid concentration device is a heated evaporator.