Heat pump belt dryer

Abstract

This utility model relates to the field of drying equipment technology and discloses a heat pump belt dryer, including a drying chamber and a heat pump system. The drying chamber is equipped with: a material conveying device for carrying and conveying the material to be dried; and a hot air circulation device for evenly blowing hot air generated by the heat pump system onto the material, thereby improving drying efficiency. This utility model uses a heat pump system as a heat source, which significantly reduces energy consumption compared to traditional heat sources and improves drying efficiency. The hot air circulation device, first air channel, second air channel, and stainless steel conveyor belt ensure that the heat generated by the heat pump is evenly distributed onto the material.

Description

Technical Field

[0001] This utility model relates to the field of drying equipment technology, and in particular to a heat pump belt dryer. Background Technology

[0002] Traditional belt dryers generally use heat sources such as steam, electric heating elements, or fuel oil combustion. Their technical systems have significant drawbacks: firstly, these heat sources have low heat conversion efficiency (steam boilers typically have a thermal efficiency of less than 85%, and electric heating radiation losses reach 12%-18%), with energy costs accounting for 30%-45% of total production costs; secondly, combustion-based heat sources produce NOx. x The emissions of harmful gases such as SO2 and electric heating devices are problematic due to peak and valley load conflicts with the power grid, making it difficult to meet the green transformation needs of the drying industry under the goal of carbon neutrality.

[0003] Existing heat pump technology has shown significant advantages in the field of cooling / heating. Based on the energy transport mechanism of the reverse Carnot cycle, it can achieve an energy efficiency ratio of 3-4 times the heat output with 1 unit of electrical energy, saving about 60% more energy than traditional electric heating.

[0004] However, when this technology is applied to belt drying, there are two major technical bottlenecks: one is how to ensure that the heat generated by the heat pump is evenly distributed to the material, and the other is how to utilize the hot and humid air discharged during the drying process to achieve energy recovery and reuse. Utility Model Content

[0005] The purpose of this utility model is to solve the problems existing in the prior art by proposing a heat pump belt dryer.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A heat pump belt dryer includes a drying chamber and a heat pump system; The drying chamber is equipped with: Material conveying device, used to carry and transport materials to be dried; The hot air circulation device evenly blows the hot air generated by the heat pump system onto the material, improving drying efficiency; The dehumidification system is used to reduce humidity in a dry room.

[0007] Preferably, the material conveying device is a belt conveyor, and a number of belt conveyors are arranged in parallel at equal intervals in the longitudinal direction inside the drying chamber.

[0008] Preferably, supports are installed on both sides of the drying chamber, the belt conveyor is installed between the two supports, a first air flow channel is provided between the side of the support away from the belt conveyor and the inner wall of the drying chamber, and a second air flow channel is provided between each pair of belt conveyors, the belt conveyor being a stainless steel conveyor belt.

[0009] Preferably, a partition is installed below the two supports to divide the drying chamber into a conveying area for installing a belt conveyor and a circulation chamber for airflow circulation. The hot air circulation device adopts a circulating fan and is installed on one side of the circulation chamber. The circulating fan delivers gas into the first air flow channel. The gas passes through the second air flow channel and the stainless steel conveyor belt from the first air flow channel on the other side of the drying chamber into the circulation chamber, and then enters the input end of the circulating fan.

[0010] Preferably, the heat pump system includes a casing installed in the circulation chamber on the side away from the circulation fan, located directly below the first air flow channel. The casing contains a heat pump unit, which includes an evaporator, a compressor, and a condenser. The evaporator absorbs heat from the outside air or the humid air in the drying room, and after being heated by the compressor, the heat is released in the condenser to heat the dry air. The dry air is then sent into the delivery area by the circulation fan.

[0011] Preferably, the dehumidification system includes a dehumidification fan installed on the top of the drying chamber, and the dehumidification fan is connected to the inner cavity of the drying chamber through a dehumidification pipe.

[0012] Preferably, a rock wool insulation layer with a thickness of 80 mm is provided on the outside of the drying room.

[0013] Preferably, the belt conveyors are staggered, with the upper conveying unit and the lower conveying unit arranged in a stepped stacked manner. One end of the lowest belt conveyor extends to the outside of the drying chamber, and a stainless steel cover is installed at the position corresponding to the outer end of the belt conveyor in the drying chamber. A discharge port is provided on the bottom side of the stainless steel cover away from the drying chamber.

[0014] Preferably, an inclined feeder is provided on the side of the discharge port away from the drying chamber, and the discharge end of the inclined feeder is connected to the feed port of the drying chamber, which is located above the uppermost belt conveyor.

[0015] Preferably, a fresh air inlet is provided on the side of the drying chamber away from the circulating fan, and the fresh air inlet is connected to the first air flow channel and is equipped with a valve. A temperature sensor and a humidity sensor are installed inside the drying chamber.

[0016] Compared with the prior art, the beneficial effects of this utility model are: 1. Energy-saving and efficient: The heat pump system is used as the heat source, which significantly reduces energy consumption compared to traditional heat sources and improves drying efficiency. The heat generated by the heat pump is evenly distributed to the material through the hot air circulation device, the first air channel, the second air channel and the stainless steel conveyor belt.

[0017] 2. Humid air circulates in a closed loop between the drying chamber and the heat pump, reducing heat loss; 3. The heat pump principle is used to recover the latent heat of condensation of water. The heat absorbed by the evaporator during dehumidification is transferred to the condenser to heat the air through the refrigerant, realizing efficient energy reuse and reducing additional energy consumption. 4. Environmentally friendly and pollution-free: The heat pump system does not produce harmful emissions during operation, meeting environmental protection requirements.

[0018] 5. Wide range of applications: Suitable for drying various sheet-like and strip-like materials with good air permeability, such as food, pharmaceuticals, and chemical raw materials. Attached Figure Description

[0019] Figure 1 This is a front view of a heat pump belt dryer proposed in this utility model; Figure 2 This is a schematic diagram of the inlet and outlet of a heat pump belt dryer proposed in this utility model. Figure 3 This is a side sectional view of the drying chamber of a heat pump belt dryer proposed in this utility model; Figure 4 This is a schematic diagram of the casing of a heat pump belt dryer proposed in this utility model; Figure 5 This is a schematic diagram of the heat pump unit principle of a heat pump belt dryer proposed in this utility model.

[0020] In the diagram: 1. Drying chamber; 2. Belt conveyor; 3. Support frame; 4. First air duct; 5. Second air duct; 6. Partition; 7. Conveying area; 8. Circulation chamber; 9. Chassis; 10. Heat pump unit; 11. Circulating fan; 12. Exhaust fan; 13. Exhaust pipe; 14. Stainless steel cover; 15. Fresh air inlet; 16. Feed inlet; 17. Discharge outlet; 18. Inclined feeder. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0022] Reference Figures 1-5 A heat pump belt dryer includes a drying chamber 1 and a heat pump system; The drying chamber 1 is equipped with: Material conveying device, used to carry and transport materials to be dried; The hot air circulation device evenly blows the hot air generated by the heat pump system onto the material, improving drying efficiency; The dehumidification system is used to reduce the humidity in the drying chamber 1.

[0023] In this embodiment, the material conveying device adopts a belt conveyor 2, and the number of belt conveyors 2 is set in a plurality of them, and the plurality of belt conveyors 2 are arranged in parallel at equal intervals in the longitudinal direction inside the drying chamber 1.

[0024] In this embodiment, brackets 3 are installed on both sides of the interior of the drying chamber 1, and the belt conveyor 2 is installed between the two brackets 3. A first air flow channel 4 is provided between the side of the bracket 3 away from the belt conveyor 2 and the inner wall of the drying chamber 1. A second air flow channel 5 is provided between each pair of belt conveyors 2. The belt conveyor 2 is made of stainless steel conveyor belt.

[0025] In this embodiment, a partition 6 is installed below the two supports 3, dividing the drying chamber 1 into a conveying area 7 for installing the belt conveyor 2 and a circulation chamber 8 for airflow circulation. The hot air circulation device adopts a circulating fan 11, which is installed on one side of the circulation chamber 8. The circulating fan 11 delivers gas into the first air channel 4. The gas passes through the second air channel 5 and the stainless steel conveyor belt and enters the circulation chamber 8 from the first air channel 4 on the other side of the drying chamber 1, and then enters the input end of the circulating fan 11. The first air channel 4 (inner wall side of the drying chamber 1) and the second air channel 5 (mesh belt gap) form a layered air distribution structure, which, together with the circulating fan 11, forces convection, so that the wind speed is uniform when the hot air penetrates the material layer.

[0026] In this embodiment, the heat pump system includes a casing 9 installed in the circulation chamber 8 on the side away from the circulating fan 11. The casing 9 has openings on the top and both sides, with the top opening located directly below the first air flow channel 4. A heat pump unit 10 is installed inside the casing 9. The heat pump unit 10 includes an evaporator, a compressor, and a condenser. The condenser is located at the inner opening, and the evaporator is located at the outer opening, separated from the condenser by a baffle. The evaporator is connected to the external space, and the connecting pipes on the heat pump unit 10 pass through the baffle (not shown in the figure). The evaporator absorbs heat from the outside air or the humid air in the drying room, and after being heated by the compressor, it releases heat in the condenser to heat the dry air. The dry air is then sent into the delivery area 7 by the circulating fan 11 (the principle of heat pump is a well-known technology and will not be described in detail here).

[0027] In this embodiment, the dehumidification system includes a dehumidification fan 12 installed on the top of the drying chamber 1, and the dehumidification fan 12 is connected to the inner cavity of the drying chamber 1 through a dehumidification pipe 13.

[0028] In this embodiment, a rock wool insulation layer with a thickness of 80mm is provided on the outside of the drying chamber 1, which can effectively reduce heat loss.

[0029] In this embodiment, several belt conveyors are designed in a staggered manner, with the upper conveying unit and the lower conveying unit arranged in a stepped stacked arrangement. One end of the lowest belt conveyor 2 extends to the outside of the drying chamber 1, and a stainless steel cover 14 is installed at the position corresponding to the outer end of the drying chamber 1 and the belt conveyor 2. The bottom of the stainless steel cover 14 is provided with a discharge port 17 on the side away from the drying chamber 1. The longitudinally parallel multi-layer stainless steel mesh belts are arranged in a stepped stacked arrangement, and the material is automatically dropped to the lower layer by gravity, realizing material turning and extending the drying path. Compared with a single-layer mesh belt, the hot air contact area is increased by more than 50%, and the drying uniformity is significantly improved.

[0030] In this embodiment, an inclined feeder 18 is provided on the side of the discharge port 17 away from the drying chamber 1. The discharge end of the inclined feeder 18 is connected to the feed inlet 16 of the drying chamber 1. The feed inlet 16 is located above the uppermost belt conveyor 2. The inclined feeder 18 and the discharge port 17 are located on the same side of the equipment.

[0031] In this embodiment, a fresh air inlet 15 is provided on the side of the drying chamber 1 away from the circulating fan 11, and the fresh air inlet 15 is connected to the first air flow channel 4. An electric air valve is provided on it. A temperature sensor and a humidity sensor are provided inside the drying chamber 1. When the humidity sensor is triggered, the fresh air inlet 15 accurately introduces external air to avoid condensation due to low humidity in the later stage of drying. When the humidity sensor is triggered, the dehumidification fan 12 starts to discharge the moisture inside the drying chamber 1. The temperature sensor monitors the temperature inside the drying chamber 1. The indoor temperature can be adjusted in conjunction with the fresh air inlet 15. It should be noted that the sensors control the dehumidification fan 12 and the electric air valve through the control processor in the prior art, which will not be elaborated on here.

[0032] Working principle: After the device is started, the heat pump transfers heat through the refrigeration system (evaporator, compressor, condenser, expansion valve). The refrigerant absorbs heat from the outside air or the humid air in the drying room in the evaporator coil. After being heated by the compressor, the heat is released in the heating heat exchange coil (condenser) to heat the dry air. The dry air is then sent into the drying chamber 1 by the circulating fan 11. The Chinese medicinal materials (used for drying Chinese medicinal materials in this embodiment) are evenly arranged on the stainless steel conveyor belt through the feed inlet 16. They move in a meandering and uniform manner within the drying chamber 1 with the conveyor belt and are automatically turned over. By transferring heat to the Chinese medicinal materials, the moisture inside the materials is removed.

[0033] Compared with existing technologies, this device has the following characteristics: 1. Energy-saving and efficient: The heat pump system is used as the heat source, which significantly reduces energy consumption compared to traditional heat sources and improves drying efficiency. The heat generated by the heat pump is evenly distributed to the material through the hot air circulation device, the first air channel 4, the second air channel 5, and the stainless steel conveyor belt.

[0034] 2. Humid air circulates in a closed loop between the dry chamber 1 and the heat pump, reducing heat loss; 3. The heat pump principle is used to recover the latent heat of condensation of water. The heat absorbed by the evaporator during dehumidification is transferred to the condenser to heat the air through the refrigerant, realizing efficient energy reuse and reducing additional energy consumption. 4. Environmentally friendly and pollution-free: The heat pump system does not produce harmful emissions during operation, meeting environmental protection requirements.

[0035] 5. Wide range of applications: Suitable for drying various sheet-like and strip-like materials with good air permeability, such as food, pharmaceuticals, and chemical raw materials.

[0036] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A heat pump belt dryer, characterized in that: Includes belt conveyors, drying chambers, and heat pump systems; The drying chamber is equipped with: Material conveying device, used to carry and transport materials to be dried; The hot air circulation device evenly blows the hot air generated by the heat pump system onto the material, improving drying efficiency; Dehumidification system, used to reduce humidity in dry indoor spaces; The drying chamber is equipped with supports on both sides, and the belt conveyor is installed between the two supports. A first air flow channel is provided between the side of the support away from the belt conveyor and the inner wall of the drying chamber. A second air flow channel is provided between each pair of belt conveyors. The belt conveyor uses a stainless steel conveyor belt. A partition is installed below the two supports, dividing the drying chamber into a conveying area for installing a belt conveyor and a circulation chamber for airflow circulation. The hot air circulation device uses a circulating fan, which is installed on one side of the circulation chamber. The circulating fan delivers gas into the first air flow channel. The gas passes through the second air flow channel and the stainless steel conveyor belt from the first air flow channel on the other side of the drying chamber into the circulation chamber, and then enters the input end of the circulating fan. The heat pump system includes a casing installed in the circulation chamber on the side away from the circulation fan, located directly below the first air flow channel. The casing contains a heat pump unit, which includes an evaporator, a compressor, and a condenser. The evaporator absorbs heat from the outside air or the humid air in the drying room. After being heated by the compressor, the heat is released in the condenser to heat the dry air. The dry air is then sent into the delivery area by the circulation fan. The belt conveyors are designed in a staggered manner, with the upper conveying unit and the lower conveying unit arranged in a stepped stacked manner. One end of the lowest belt conveyor extends to the outside of the drying room, and a stainless steel cover is installed at the position corresponding to the outer end of the drying room and the belt conveyor. The bottom of the stainless steel cover is provided with a discharge port on the side away from the drying room.

2. The heat pump belt dryer according to claim 1, characterized in that: The material conveying device uses belt conveyors, and there are several of them arranged longitudinally and parallel to each other inside the drying chamber.

3. A heat pump belt dryer according to claim 2, characterized in that: The dehumidification system includes a dehumidification fan installed on the top of the drying chamber. The dehumidification fan is connected to the inner cavity of the drying chamber through a dehumidification pipe to extract humid air from the drying chamber and reduce the humidity of the air in the drying chamber.

4. A heat pump belt dryer according to claim 3, characterized in that: The exterior of the drying room is equipped with a rock wool insulation layer with a thickness of 80mm.

5. A heat pump belt dryer according to claim 4, characterized in that: An inclined feeder is installed on the side of the discharge port away from the drying chamber. The discharge end of the inclined feeder is connected to the feed inlet of the drying chamber, which is located above the uppermost belt conveyor.

6. A heat pump belt dryer according to claim 1, characterized in that: A fresh air inlet is provided on the side of the drying chamber away from the circulating fan, and the fresh air inlet is connected to the first air flow channel. A valve is provided on the inlet. Temperature and humidity sensors are provided inside the drying chamber.

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