A dehumidifying and drying device capable of recycling heat energy

Abstract

The utility model discloses a kind of dehumidification drying devices of recyclable regenerative heat energy, including two groups of identical structure dehumidification tower module, the outlet end of dehumidification tower module is connected to the drying air outlet of drying device and regeneration air reversing valve by outlet reversing valve, regeneration air reversing valve is connected to regeneration exhaust port, the inlet end of dehumidification tower module is respectively connected to connection back air water cooler by inlet reversing valve, back air water cooler other end connects drying fan, another end of drying fan connects back air filter, back air filter other end is connected to the drying back air outlet of drying device, the inlet end of dehumidification tower module is also connected to regeneration fan by inlet reversing valve, a kind of dehumidification drying devices of recyclable regenerative heat energy of the utility model, most of the residual heat energy in dehumidification tower after regeneration can be used for subsequent drying process, appropriately improve the initial temperature of drying air, while reducing the energy consumption of subsequent drying process, drying process also will not have relatively big disturbance.

Description

Technical Field

[0001] This utility model belongs to the field of dryer technology, and in particular relates to a dehumidifying and drying device that can recover and regenerate heat energy. Background Technology

[0002] In the production of plastic products, low-dew-point air is typically required to dry highly hygroscopic engineering plastic raw materials. After a dehumidifying dryer has been producing low-dew-point air for an extended period, hot air is needed to regenerate the adsorbent, removing moisture and allowing the adsorbent to reabsorb moisture.

[0003] Traditional dehumidifiers often employ multiple dehumidification towers during operation. Taking a dual-tower dehumidifier as an example, while dehumidifier tower one is performing adsorption, dehumidifier tower two is regenerating the adsorbent. The regeneration process mainly consists of two steps: heating and drainage, and cooling. After the adsorbent in dehumidifier tower two is regenerated, it enters a standby state. When the airflow generated by dehumidifier tower one is insufficient to meet the drying requirements, the airflow path is switched, dehumidifier tower two begins adsorption, and dehumidifier tower one begins regeneration, thus repeating the cycle.

[0004] During regeneration, a heater is used to heat the gas, and the hot regeneration gas is blown into the dehumidification tower to remove moisture from the adsorbent and then discharged from the dryer. After the moisture is removed, the dehumidification tower is cooled using water or air cooling, and it can only be switched to operation after cooling is complete.

[0005] The energy consumption of a dehumidifying dryer mainly comes from the normal drying air generation and regeneration processes, especially the regeneration process, which consumes a lot of energy.

[0006] After the traditional dehumidifier is regenerated and heated, the heat inside the dehumidifier tower is carried away by the air cooler or water cooler during the cooling process, resulting in low energy utilization.

[0007] Traditional dehumidifiers operate by passing the process air through only one dehumidification tower, resulting in high airflow resistance and energy consumption. Therefore, a solution is needed to address these issues.

[0008] It should be noted that the above content falls within the inventor's technical knowledge and does not necessarily constitute prior art. Utility Model Content

[0009] To address the aforementioned problems, the purpose of this invention is to provide a dehumidifying and drying device that can recover residual heat energy from the regenerated dehumidifying tower for subsequent drying processes, thereby increasing the initial temperature of the drying air and reducing energy consumption in subsequent drying processes.

[0010] To achieve the above objectives, this utility model proposes a dehumidification and drying device capable of recovering and regenerating heat energy, comprising two sets of dehumidification tower modules with identical structures. The outlet end of each dehumidification tower module is connected to the drying air outlet and the regeneration air reversing valve of the drying device via an outlet reversing valve. The regeneration air reversing valve is connected to the regeneration exhaust port. The inlet end of each dehumidification tower module is connected to a return air water cooler via an inlet reversing valve. The other end of the return air water cooler is connected to a drying fan. The other end of the drying fan is connected to a return air filter. The other end of the return air filter is connected to the drying return air outlet of the drying device. The inlet end of each dehumidification tower module is also connected to the regeneration fan via an inlet reversing valve.

[0011] In one example, the dehumidification tower module includes a dehumidification tower, an inlet temperature sensor, an outlet temperature sensor, and a heater. The inlet temperature sensor and the outlet temperature sensor are located at opposite ends of the dehumidification tower. The inlet temperature sensor is located on the side of the dehumidification tower closer to the inlet reversing valve, and the outlet temperature sensor is located on the side of the dehumidification tower closer to the outlet reversing valve. The heater is located between the inlet temperature sensor and the inlet reversing valve.

[0012] In one example, the dehumidification tower is equipped with an adsorbent.

[0013] In one example, a flow-limiting orifice plate is provided between the drying air outlet and the regeneration air reversing valve.

[0014] In one example, the inlet reversing valve, the outlet reversing valve, and the regenerated air reversing valve are all three-way valves.

[0015] In one example, the number of dehumidification tower modules can be greater than or equal to two.

[0016] In one example, the dehumidification tower modules are arranged in parallel.

[0017] The dehumidification and drying device with recyclable heat energy proposed in this utility model can bring the following beneficial effects:

[0018] 1. Most of the residual heat energy in the dehumidification tower after regeneration can be used for the subsequent drying process. The initial temperature of the drying air is appropriately increased, which reduces the energy consumption of the subsequent drying process without causing significant disturbance to the drying process.

[0019] 2. During heat recovery, the two dehumidification towers are connected in parallel, which can reduce the overall resistance of the airflow inside the dryer and reduce the energy consumption of the dryer fan.

[0020] 3. The capacity of the dryer can be expanded by adding a dehumidification tower, heater, inlet reversing valve, outlet reversing valve, inlet temperature sensor, and outlet temperature sensor, thereby realizing the modular expansion design of the dryer's air path and reducing design costs.

[0021] 4. It can reduce the fluctuation of the dew point value of the system dry air when switching the dehumidification tower working mode.

[0022] 5. Because the drying device has a regenerative heat recovery function, the dryer does not need to be equipped with a regenerative water cooler. Attached Figure Description

[0023] The accompanying drawings, which are included to provide a further understanding of the present invention and constitute a part of this invention, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:

[0024] Figure 1 This is a schematic diagram of the airflow principle for the regenerative open-loop heating and open-loop cooling stages of this utility model.

[0025] Figure 2 This is a schematic diagram of the airflow path for the regeneration closed-loop cooling stage and drying stage of this utility model.

[0026] Figure 3 This is a schematic diagram of the extended airflow path of this utility model. Detailed Implementation

[0027] To more clearly illustrate the overall concept of this utility model, a detailed description will be provided below with reference to the accompanying drawings.

[0028] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0031] In this invention, unless otherwise expressly specified and limited, the first feature "on" or "below" the second feature may be in direct contact with the first and second features, or indirect contact through an intermediate medium. In the description of this specification, references to terms such as "a solution," "some solutions," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that solution or example is included in at least one solution or example of this invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same solution or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more solutions or examples.

[0032] like Figures 1-3 As shown in the figure, an embodiment of this utility model proposes a dehumidifying and drying device that can recover regenerated heat energy, including two sets of dehumidifying tower modules 1 with identical structures. The outlet end of the dehumidifying tower module 1 is connected to the drying air outlet 3 and the regenerated air reversing valve 4 of the drying device through the outlet reversing valve 2. The regenerated air reversing valve 4 is connected to the regenerated exhaust port 5. The inlet end of the dehumidifying tower module 1 is connected to the outlet of the heater 15. The inlet of the heater 15 is connected to the inlet reversing valve 10. The inlet reversing valve 10 is connected to the return air water cooler 6. The other end of the return air water cooler 6 is connected to the drying fan 7. The other end of the drying fan 7 is connected to the return air filter 8. The other end of the return air filter 8 is connected to the drying return air port 9 of the drying device. The inlet end of the dehumidifying tower module 1 is also connected to the regenerated fan 11 through the inlet reversing valve 10. The inlet of the regenerated fan 11 is connected to the atmosphere.

[0033] The inlet reversing valve 10 of each dehumidification tower 12 can be independently controlled in direction, thus enabling each dehumidification tower 13 to be individually connected to the regeneration fan 11 or simultaneously connected to the drying fan 7. The outlet reversing valve 2 of the dehumidification tower 12 can be controlled in the opposite direction.

[0034] An independent regeneration fan 11 draws ambient air from the atmosphere for the open-loop heating and cooling stages of regeneration, and the open-loop regeneration air path is isolated from the drying circuit.

[0035] Specifically, the dehumidification tower module 1 includes a dehumidification tower 12, an inlet temperature sensor 13, an outlet temperature sensor 14, and a heater 15. The inlet temperature sensor 13 and the outlet temperature sensor 14 are located at opposite ends of the dehumidification tower 12. The inlet temperature sensor 13 is located on the side of the dehumidification tower 12 closest to the inlet reversing valve 11, and the outlet temperature sensor 14 is located on the side of the dehumidification tower 12 closest to the outlet reversing valve 10. The heater 15 is located between the inlet temperature sensor 13 and the inlet reversing valve 10.

[0036] The outlet temperature sensor 14 of the dehumidification tower 13 is used to detect the temperature at the outlet of the dehumidification tower 13 to determine the regeneration status. Based on this information, the regeneration steps are switched. The outlet temperature determines the end point of the external circulation heating stage; the outlet temperature determines the end point of the open-loop cooling stage; the outlet temperature determines the end point of the closed-loop cooling stage, which is also the end point of the entire regeneration process.

[0037] Specifically, a flow-limiting orifice plate 16 is installed between the drying air outlet 3 and the regeneration air reversing valve 4.

[0038] The regeneration exhaust port 5 can be switched to connect to the atmosphere or to the dry air outlet via the regeneration air reversing valve 4. When connected to the dry air outlet, an appropriate flow-limiting orifice plate 16 controls the ratio of hot air to cold air in the dehumidification tower 13. The temperature rise of the combined dry air should not exceed 5°C to prevent large temperature fluctuations in the subsequent material drying process.

[0039] Specifically, the dehumidification tower 12 is equipped with an adsorbent 17.

[0040] Immediately after the regeneration heating ends, the temperature of the adsorbent 17 inside the dehumidification tower 12 is extremely high, reaching 250°C at the inlet and 200°C at the outlet. At this point, the outlet air temperature of the dehumidification tower 12 has a significant temperature difference compared to the normal dry air temperature. Even with the flow-limiting orifice plate 16 to restrict the airflow ratio, heat recovery is not possible. Therefore, after the regeneration heating and drainage stage, an external circulation cooling stage is required to maintain the valve position and airflow path. First, the heater 15 is cooled by ambient air to protect it. Then, the adsorbent 17 at the bottom of the dehumidification tower 12 is cooled, allowing this portion of the adsorbent 17 to perform moisture adsorption during heat recovery. Only after the overall temperature of the adsorbent 17 inside the dehumidification tower 12 has slightly decreased can the heat recovery process be switched to.

[0041] Regenerative heat recovery is a slow cooling process. Compared with traditional dryers that directly use air coolers or water coolers, the regeneration cooling stage takes much longer. Therefore, there are high requirements for the drying time of each dehumidification tower 12. After each dehumidification tower 12 completes regeneration, the continuous working time until the next regeneration begins needs to be longer than the regeneration time of another dehumidification tower 12.

[0042] Specifically, the inlet reversing valve 10, the outlet reversing valve 2, and the regenerated air reversing valve 4 are all three-way valves.

[0043] Specifically, the number of dehumidification tower modules 1 can be greater than or equal to two. That is, by adding dehumidification towers, heaters, inlet reversing valves, outlet reversing valves, inlet temperature sensors, and outlet temperature sensors, the capacity of the dryer can be expanded, realizing the modular expansion design of the air path of the dryer and reducing design costs.

[0044] Specifically, the various dehumidification tower modules 1 are arranged in parallel, which can reduce the overall resistance of the internal airflow of the dryer and reduce the energy consumption of the drying fan.

[0045] like Figure 2 As shown, the initial state assumes that dehumidifier tower No. 2 is in the drying stage. The inlet reversing valve of dehumidifier tower No. 2 is in the drying direction, and the outlet reversing valve of dehumidifier tower No. 2 is also in the drying direction. The return air from outside the loop passes through the return air filter and the drying fan, and is then cooled by the return air water cooler. After passing through the inlet reversing valve of dehumidifier tower No. 2, it enters dehumidifier tower No. 2. After the air in dehumidifier tower No. 2 has absorbed all the moisture, it leaves the dryer after passing through the outlet reversing valve of dehumidifier tower No. 2 and is used for the subsequent raw material drying process.

[0046] like Figure 1 As shown, when the drying unit is in the regeneration open-loop heating stage, the inlet reversing valve of dehumidifier tower No. 1 switches to the regeneration direction, the outlet reversing valve of dehumidifier tower No. 1 switches to the regeneration direction, the regeneration air reversing valve switches to the exhaust direction, the regeneration fan operates, and the heater of dehumidifier tower No. 1 operates. Normal temperature air passes through the regeneration fan and the inlet reversing valve of dehumidifier tower No. 1, and is heated by the heater. The inlet temperature sensor of the dehumidifier tower after the heater detects the heating temperature and controls the output power of the heater through the control system to ensure a constant inlet temperature of the dehumidifier tower. After the hot air passes through dehumidifier tower No. 1 and the outlet reversing valve of dehumidifier tower No. 1, the exhaust gas is discharged into the atmosphere through the regeneration air reversing valve. The outlet temperature sensor of the dehumidifier tower detects the outlet temperature of the dehumidifier tower, and the timing for ending the open-loop heating stage is determined by the outlet temperature.

[0047] like Figure 1 As shown, after the open-loop heating stage ends, the open-loop cooling stage begins. Heater No. 1 of the dehumidifier tower is shut off, while the remaining valves remain in their original positions. At room temperature air continues to cool the heater and the adsorbent at the bottom of the dehumidifier tower. The outlet temperature sensor of the dehumidifier tower detects the outlet temperature, and the timing for ending the open-loop cooling stage is determined by the outlet temperature.

[0048] like Figure 2As shown, after the open-loop cooling stage ends, the closed-loop cooling stage begins. The inlet reversing valve of dehumidifier tower 1 switches to the drying direction, the outlet reversing valve of dehumidifier tower 1 remains in the regeneration direction, the regeneration air reversing valve switches to the drying direction, and the regeneration fan stops operating. At this time, the return air cooled by the return air water cooler is simultaneously sent into both dehumidifier towers in parallel. Dehumidifier tower 2, which is in the drying stage, remains in its original state, while the heat in dehumidifier tower 1, which is in the regeneration stage, is carried away by the return air. Through the regeneration air reversing valve and the flow limiting orifice plate, it mixes with the dry air coming out of dehumidifier tower 2, increasing the temperature of the dry air. Due to the effect of the flow-limiting orifice plate after the regeneration air reversing valve, the air volume of Dehumidifier Tower No. 1 in the regeneration state is relatively small, which will not cause large fluctuations in the temperature of the mixed dry air. In addition, the adsorbent at the bottom of Dehumidifier Tower No. 1 has been cooled completely in the open-loop cooling stage, so in the closed-loop cooling stage, the adsorbent at the bottom has recovered its moisture adsorption capacity, which is sufficient for adsorption and drying of small air volumes, and will not cause large fluctuations in the dew point of the mixed dry air. The outlet temperature sensor of the dehumidifier tower detects the outlet temperature of the dehumidifier tower and determines the timing of ending the closed-loop cooling stage based on the outlet temperature.

[0049] After the closed-loop cooling phase ends, the valves in the air path do not switch at all, and the two dehumidification towers remain in parallel. At this time, the working state is switched according to the switching conditions of the dehumidification towers. The simultaneous operation of the two dehumidification towers can reduce the fluctuation of the dew point value of the dry air during the switching.

[0050] Working principle: During the normal drying process, the air returns to the dryer from the return air inlet. The air first passes through the return air filter, and the filtered return air enters the drying fan. The outlet of the drying fan is connected to the return air water cooler. The cooled air passes through the inlet reversing valve of the dehumidification tower and is blown into the dehumidification tower. After passing through the dehumidification tower, the moisture is removed by the adsorbent. After passing through the outlet reversing valve of the dehumidification tower, the air is blown out from the dryer outlet.

[0051] When a dehumidifier tower is regenerated, the first stage is heating. The inlet reversing valve of the dehumidifier tower switches to the regeneration fan side. The regeneration fan draws air from the atmosphere and blows it into the system. After passing through the inlet reversing valve of the dehumidifier tower, the air is heated to the regeneration temperature by the heater and then enters the dehumidifier tower. After the adsorbent inside the dehumidifier tower is continuously heated by the hot air, the moisture in the adsorbent slowly precipitates out and is carried away by the air. At this time, the outlet reversing valve of the dehumidifier tower switches to the regeneration direction. After passing through the outlet reversing valve, the moisture is discharged into the atmosphere through the regeneration air reversing valve.

[0052] After regeneration heating is complete, the heater stops heating the air, and all valves remain in their positions. The regeneration fan continues to use ambient air to cool the heater and adsorbent, and the hot air is discharged from the dryer. Once the outlet temperature of the dehumidification tower drops to a certain level, the regeneration fan stops, the inlet reversing valve of the dehumidification tower switches to the drying position, and the regeneration air reversing valve switches to the closed-loop position. At this point, the regenerated dehumidification tower is integrated into the drying loop. The air from the drying fan is simultaneously blown into each dehumidification tower of the drying unit, except that the outlet reversing valve of the regenerated dehumidification tower remains in the regeneration position. After passing through the regeneration air reversing valve, the air passes through a flow-limiting orifice plate that restricts the airflow on the regenerated dehumidification tower side before entering the drying air outlet. Because the air passing through the return air cooler is cold, it passes through one dehumidification tower to produce drying air, and a portion of it also enters the regeneration dehumidification tower to cool the adsorbent inside. The hot air blown out mixes with the normal outlet drying air, increasing the temperature of the drying air.

[0053] During the subsequent material drying process, the drying temperature remains constant. The higher the initial air temperature, the lower the energy consumption of the drying heater.

[0054] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0055] The above description is merely an embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.

Claims

1. A dehumidifying and drying device capable of recovering and regenerating heat energy, characterized in that, The device includes two sets of identical dehumidification tower modules. The outlet end of each dehumidification tower module is connected to the drying air outlet and regeneration air reversing valve of the drying device via an outlet reversing valve. The regeneration air reversing valve is connected to the regeneration exhaust port. The inlet end of each dehumidification tower module is connected to a return air water cooler via an inlet reversing valve. The other end of the return air water cooler is connected to a drying fan. The other end of the drying fan is connected to a return air filter. The other end of the return air filter is connected to the drying return air outlet of the drying device. The inlet end of each dehumidification tower module is also connected to a regeneration fan via an inlet reversing valve.

2. The dehumidifying and drying device with recoverable and regenerable heat energy according to claim 1, characterized in that, The dehumidification tower module includes a dehumidification tower, an inlet temperature sensor, an outlet temperature sensor, and a heater. The inlet temperature sensor and the outlet temperature sensor are located at both ends of the dehumidification tower. The inlet temperature sensor is located on the side of the dehumidification tower closer to the inlet reversing valve, and the outlet temperature sensor is located on the side of the dehumidification tower closer to the outlet reversing valve. The heater is located between the inlet temperature sensor and the inlet reversing valve.

3. The dehumidifying and drying device with recoverable and regenerable heat energy according to claim 2, characterized in that, The dehumidification tower is equipped with an adsorbent.

4. The dehumidifying and drying device with recoverable and regenerable heat energy according to claim 1, characterized in that, A flow-limiting orifice plate is provided between the drying air outlet and the regeneration air reversing valve.

5. The dehumidifying and drying device with recoverable and regenerable heat energy according to claim 1, characterized in that, The inlet reversing valve, the outlet reversing valve, and the regenerated air reversing valve are all three-way valves.

6. The dehumidifying and drying device with recoverable and regenerable heat energy according to claim 1, characterized in that, The number of dehumidification tower modules can be greater than or equal to two.

7. The dehumidifying and drying device with recoverable and regenerable heat energy according to claim 1, characterized in that, The dehumidification tower modules are arranged in parallel.

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