A pressure swing gas drying apparatus and method

Abstract

The application discloses a kind of gas pressure swing drying device and method, device includes: drying chamber, gas circulation unit and pressure control unit, drying chamber has drying cavity and the gas inlet and gas outlet that communicate drying cavity;Gas circulation unit communicates drying cavity to drive the circulating flow of air in drying cavity;Pressure control unit communicates drying cavity to control the air pressure in drying cavity.The method comprises the following steps: S1 material is placed into drying cavity, and pressure control unit makes the air pressure in drying cavity rise to preset high pressure value;S2 gas circulation unit drives the circulating flow of air in drying cavity, while pressure control unit makes the air pressure in drying cavity drop to low pressure value.The application changes the air pressure in drying cavity by pressure control unit, first air pressure is promoted to high pressure value, most of the water in material is squeezed out quickly, then air pressure is reduced to low pressure value, promote the evaporation of residual moisture of material, and this drying mode significantly reduces energy consumption, and it is suitable for heat-sensitive material.

Description

Technical Field

[0001] This invention relates to the field of drying technology, specifically to a gas pressure swing drying apparatus and method. Background Technology

[0002] In industrial production and daily life, material drying is a crucial step, directly impacting product quality, production efficiency, and energy consumption. Currently, mainstream drying technologies rely on low-temperature or atmospheric-pressure gases, heating materials to evaporate moisture. The effect of saturated vapor pressure on moisture content is primarily reflected in changes in pressure and temperature. At the same temperature, the saturated vapor pressure of water remains relatively constant. When the total pressure increases, previously saturated water condenses as the partial pressure increases, leading to a decrease in the content of gaseous water. Higher temperatures result in more water vapor in indoor air, while lower temperatures result in less water vapor. This is because higher temperatures lead to higher saturated vapor pressure and thus higher saturated moisture content per unit volume of air; conversely, lower temperatures lead to lower saturated vapor pressure and lower moisture content in the air.

[0003] Specifically, these traditional drying technologies typically utilize heat energy as the driving force, heating the surface of the material to cause the internal moisture to escape as steam, thus achieving the drying purpose. However, this method has several significant limitations. First, it is usually energy-intensive because it requires a large amount of heat energy to drive the evaporation of moisture. Second, for some heat-sensitive materials, such as certain food, pharmaceutical, and chemical raw materials, high-temperature environments may lead to a decline in their quality or even changes in their chemical or physical properties. Although these traditional drying technologies have achieved certain results, their inherent high energy consumption and incompatibility with heat-sensitive materials remain problems that urgently need to be addressed. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a gas pressure swing drying device and method to solve the technical problems of existing technologies that use heating to dry materials, which on the one hand consumes a lot of energy and on the other hand are not suitable for heat-sensitive materials.

[0005] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a gas pressure swing drying apparatus, comprising: a drying chamber having a drying cavity and an air inlet and an air outlet communicating with the drying cavity; a gas circulation unit communicating with the drying cavity to drive air circulation within the drying cavity; and a pressure control unit communicating with the drying cavity to control the gas pressure within the drying cavity.

[0007] In some embodiments, the gas circulation unit includes a circulation pipe and a circulation fan. Both ends of the circulation pipe are connected to the drying chamber, and the circulation fan is disposed on the circulation pipe to drive the air circulation flow.

[0008] In some embodiments, the gas circulation unit further includes a drying module, which is detachably mounted on the circulation pipeline and filled with a desiccant.

[0009] In some embodiments, the pressure control unit includes an intake valve, a pressure relief valve, an intake pump, and a suction pump. The intake valve is located at the intake port, the pressure relief valve is located at the outlet port, the intake pump is connected to the intake port to pump air into the drying chamber, and the suction pump is connected to the outlet port to extract air from the drying chamber.

[0010] In some embodiments, the system further includes a control unit, which includes a controller and is connected to the intake valve, the pressure relief valve, the intake pump, the suction pump, and the circulating fan for signal control.

[0011] In some embodiments, the control unit further includes a pressure sensor, a temperature sensor, and a humidity sensor disposed in the drying chamber, and the pressure sensor, temperature sensor, and humidity sensor are respectively connected to the controller for signal transmission.

[0012] Secondly, the present invention also provides a gas pressure swing drying method applicable to a gas pressure swing drying device, comprising the following steps: S1, placing the material into the drying chamber, and raising the gas pressure in the drying chamber to a preset high pressure value through a pressure control unit; S2, driving the air circulation flow in the drying chamber through a gas circulation unit, and simultaneously lowering the gas pressure in the drying chamber to a low pressure value at a preset rate through a pressure control unit.

[0013] In some embodiments, the high pressure value is 0.6 MPa to 1.0 MPa, and the low pressure value is 0.1 kPa to 0.3 kPa.

[0014] In some embodiments, the volume of the drying chamber is 0.5 m³ to 10 m³, and the air circulation unit drives the air circulation flow at a velocity of 5 m³ / min to 10 m³ / min.

[0015] In some embodiments, the temperature of the drying chamber is 30°C to 80°C throughout the drying process.

[0016] Compared with the prior art, the gas pressure swing drying device provided by the present invention changes the gas pressure in the drying chamber through the pressure control unit. First, the gas pressure is raised to a high pressure value to quickly squeeze out most of the moisture in the material. Then, the gas pressure is reduced to a low pressure value to promote the evaporation of residual moisture in the material and ensure the drying effect. This drying method significantly reduces energy consumption and is suitable for heat-sensitive materials. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the gas pressure swing drying device provided in an embodiment of the present invention;

[0018] Figure 2 This is a flowchart of the gas pressure swing drying method provided in the embodiments of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] To address the technical problems of existing technologies that use heating to dry materials, which have high energy consumption and are not suitable for heat-sensitive materials, this invention provides a gas pressure swing drying device and method that can significantly reduce energy consumption during drying and is also suitable for heat-sensitive materials.

[0021] It should be noted that the gas pressure swing drying device described in this invention is used for, but not limited to, drying batteries. For ease of explanation, this invention will only use the gas pressure swing drying device to dry batteries as an example. The principle of the gas pressure swing drying device to dry other heat-sensitive materials is essentially the same as that of drying batteries, and will not be described in detail here.

[0022] Please see Figure 1 , Figure 1 This is a schematic diagram of a gas pressure swing drying device in one embodiment of the present invention. The gas pressure swing drying device includes a drying chamber 1, a gas circulation unit 2, and a pressure control unit 3.

[0023] The drying chamber 1 has a drying cavity and an air inlet 11 and an air outlet 12 that connect to the drying cavity. It is easy to understand that the drying chamber 1 should also have a door for placing materials. After the material to be dried (such as a battery) is placed in the drying cavity, the door is closed and drying begins.

[0024] Gas circulation unit 2 is connected to the drying chamber to drive the air circulation flow within the drying chamber.

[0025] The pressure control unit 3 is connected to the drying chamber to control the air pressure inside the drying chamber. The pressure control unit 3 can both raise the air in the drying chamber to a predetermined value and lower the air in the drying chamber to a predetermined value.

[0026] In some embodiments, the gas circulation unit 2 includes a circulation pipe 21 and a circulation fan 22. Both ends of the circulation pipe 21 are connected to the drying chamber, and the circulation fan 22 is disposed on the circulation pipe 21 to drive the air circulation flow in the drying chamber.

[0027] In some embodiments, the gas circulation unit 2 further includes a drying module 23, which is detachably mounted on the circulation pipe 21 and filled with a desiccant. The drying module 23 can further improve the drying capacity of the drying device. The drying module 23 can adopt a porous box-like structure, with a corresponding mounting groove or mounting hole provided on the circulation pipe 21, into which the drying module 23 can be installed. Preferably, it can be sealed to the circulation pipe 21, with a sealing ring used to improve the airtightness of the connection. The desiccant in the drying module 23 is generally a solid desiccant, such as quicklime or silica gel.

[0028] In some embodiments, the pressure control unit 3 includes an intake valve 31, a pressure relief valve 32, an intake pump 33, and a suction pump 34. The intake valve 31 is located at the intake port 11, and the pressure relief valve 32 is located at the outlet port 12, respectively controlling the opening and closing of the intake port 11 and the outlet port 12. The intake pump 33 is connected to the intake port 11 to pump air into the drying chamber, increasing the air pressure inside the drying chamber. The suction pump 34 is connected to the outlet port 12 to extract air from the drying chamber, reducing the air pressure inside the drying chamber to below one atmosphere.

[0029] In some embodiments, the gas pressure changing drying device further includes a control unit 4, which includes a controller 41. The controller 41 is connected to the inlet valve 313, the pressure relief valve 2, the inlet pump 33, the suction pump 34, and the circulating fan 22 for signal control, and controls their working status to achieve the purpose of controlling the gas pressure inside the drying chamber.

[0030] In some embodiments, the control unit 4 further includes a pressure sensor 42, a temperature sensor 43, and a humidity sensor 44 disposed in the drying chamber. The pressure sensor 42, the temperature sensor 43, and the humidity sensor 44 are used to monitor the air pressure, temperature, and humidity in the drying chamber, respectively, and are respectively connected to the controller 41 for signal transmission to provide data support for the controller 41 to control various components.

[0031] Please see Figure 2 , Figure 2 This is a flowchart of a gas pressure swing drying method in one embodiment of the present invention.

[0032] The gas pressure swing drying method includes the following steps: S1 The material is placed into the drying chamber, and the pressure control unit 3 raises the gas pressure in the drying chamber to a preset high pressure value, quickly squeezing out most of the moisture in the material.

[0033] The specific operation is as follows: the controller 41 controls the air intake valve 31 to open, the pressure relief valve 32 to close, and the air intake pump 33 to start working, pumping air into the drying chamber to increase the air pressure in the drying chamber until the pressure sensor 42 detects that the air pressure in the drying chamber has reached the preset high pressure value, and then controls the air intake valve 313 and the air intake pump 33 to close.

[0034] S2 gas circulation unit 2 drives the air circulation flow in the drying chamber, while the pressure control unit 3 causes the air pressure in the drying chamber to drop to a low pressure value at a preset rate, promoting the evaporation of residual moisture in the material and ensuring the drying effect.

[0035] Specifically, the controller 41 controls the circulating fan 22 to start working, driving air circulation at a certain rate. Simultaneously, it controls the pressure relief valve 32 to open to a certain extent, causing the air pressure inside the drying chamber to decrease at a preset rate. As the air pressure inside the drying chamber decreases, the exhaust rate from the outlet 12 also decreases. Therefore, the pressure relief valve 32 must be opened accordingly to compensate, keeping the rate of pressure reduction within a preset range. When the air pressure inside the drying chamber approaches one atmosphere, even with the pressure relief valve 32 opened to its maximum, it is still unable to maintain the required pressure reduction rate. At this point, the controller 41 controls the air extraction pump 34 to start working, extracting air from the drying chamber at a preset pressure reduction rate, thus lowering the air pressure inside the drying chamber to a low pressure value.

[0036] In some embodiments, the high pressure value is 0.6 MPa to 1.0 MPa, and the low pressure value is 0.1 kPa to 0.3 kPa.

[0037] In some embodiments, the volume of the drying chamber is 0.5 m³ to 10 m³, and the air circulation unit drives the air circulation flow at a velocity of 5 m³ / min to 10 m³ / min. This is the size of the drying chamber adopted by the applicant when drying batteries, taking into account factors such as the equipment installation environment and the number of batteries to be dried. In other embodiments, those skilled in the art can increase or decrease the volume of the drying chamber according to actual production needs, and correspondingly adjust the air circulation flow velocity.

[0038] In some embodiments, the temperature of the drying chamber is maintained between 30°C and 80°C throughout the drying process to prevent quality degradation of the heat-sensitive material. In step S1, the pressurization of the drying chamber by the air pump 33 is accompanied by an increase in the drying chamber temperature; therefore, the pressurization rate needs to be controlled to prevent the temperature inside the drying chamber from exceeding the upper limit. The temperature inside the drying chamber is maintained stable by utilizing the heat dissipation of the drying chamber itself. In step S2, the depressurization process in the drying chamber is also accompanied by a decrease in the drying chamber temperature; similarly, the depressurization rate is controlled to prevent the temperature inside the drying chamber from becoming too low.

[0039] In one specific embodiment, the volume of the drying chamber is customized to 5 m³ based on the actual batch size of the material to meet specific production scale requirements. In the initial drying stage, the pressure control unit 3 increases the air pressure inside the drying chamber 1 to 0.8 MPa, which quickly squeezes out most of the moisture from the material, laying a good foundation for the subsequent drying process.

[0040] Subsequently, in the later stages of drying, the gas pressure in the drying chamber is gradually reduced to 0.2 kPa. This precise pressure control strategy helps to promote the evaporation of residual moisture in the material and ensures the thoroughness of the drying effect.

[0041] Meanwhile, the gas circulation unit 2 circulates the gas in the drying chamber at a rate of 8 m³ / min, achieving a 92% gas reuse rate. This design significantly improves drying efficiency and reduces energy consumption. Furthermore, throughout the drying process, the temperature of the drying chamber 1 is precisely controlled at around 50°C to ensure that the material is not damaged by excessively high temperatures during the drying process.

[0042] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A gas pressure swing drying method, characterized in that, A gas pressure swing drying device is employed, comprising a drying chamber having a drying cavity and an air inlet and an air outlet communicating with the drying cavity; a gas circulation unit communicating with the drying cavity to drive the air circulation within the drying cavity; a pressure control unit communicating with the drying cavity to control the air pressure within the drying cavity; and a control unit comprising a controller and a temperature sensor disposed within the drying cavity, the temperature sensor being connected to the controller for signal transmission. The gas circulation unit includes a circulation pipe and a circulation fan. Both ends of the circulation pipe are connected to the drying chamber, and the circulation fan is installed on the circulation pipe to drive the air circulation flow. The pressure control unit includes an air inlet valve, a pressure relief valve, an air inlet pump, and an air extraction pump. The air inlet valve is located at the air inlet, the pressure relief valve is located at the air outlet, the air inlet pump is connected to the air inlet to pump air into the drying chamber, and the air extraction pump is connected to the air outlet to extract air from the drying chamber. The controller is connected to the intake valve, the pressure relief valve, the intake pump, the suction pump, and the circulating fan for signal control. The gas pressure swing drying method includes the following steps: S1. Place the material into the drying chamber, and use the pressure control unit to raise the air pressure in the drying chamber to a preset high pressure value. Specifically, the controller controls the air inlet valve to open, the pressure relief valve to close, and the air inlet pump to start working, pumping air into the drying chamber to increase the air pressure in the drying chamber until the pressure sensor detects that the air pressure in the drying chamber has reached the preset high pressure value, and then controls the air inlet valve and the air inlet pump to close. Pressurizing the air intake pump into the drying chamber will cause the temperature of the drying chamber to rise. It is necessary to control the pressurization rate to prevent the temperature inside the drying chamber from exceeding the upper limit. The temperature inside the drying chamber is maintained by utilizing the heat dissipation of the drying chamber itself. S2. The air in the drying chamber is circulated by the gas circulation unit, and the air pressure in the drying chamber is reduced to a low pressure value at a preset rate by the pressure control unit. Specifically, the pressure relief valve is opened to reduce the air pressure in the drying chamber at a preset rate. As the air pressure inside the drying chamber decreases, the exhaust rate from the outlet also decreases. The pressure relief valve is opened accordingly to compensate for this and keep the rate of air pressure reduction within a preset range. When the air pressure in the drying chamber approaches one atmosphere, the pressure relief valve cannot maintain the required rate of pressure reduction even when opened to its maximum. At this time, the controller controls the air pump to start working and extract the air in the drying chamber at a preset rate of pressure reduction to reduce the air pressure in the drying chamber to a low pressure value. The process of depressurizing the drying chamber is accompanied by a decrease in the temperature of the drying chamber. The depressurization rate is controlled to prevent the temperature inside the drying chamber from becoming too low.

2. The gas pressure swing drying method according to claim 1, characterized in that, The gas circulation unit also includes a drying module, which is detachably mounted on the circulation pipeline and is filled with a desiccant.

3. The gas pressure swing drying method according to claim 1, characterized in that, The control unit also includes a pressure sensor and a humidity sensor disposed in the drying chamber, and the pressure sensor and the humidity sensor are respectively connected to the controller for signal transmission.

4. The gas pressure swing drying method according to claim 1, characterized in that, The high pressure value is 0.6 MPa to 1.0 MPa, and the low pressure value is 0.1 kPa to 0.3 kPa.

5. The gas pressure swing drying method according to claim 1, characterized in that, The volume of the drying chamber is 0.5 m³ to 10 m³, and the air circulation unit drives the air circulation flow at a velocity of 5 m³ / min to 10 m³ / min.

6. The gas pressure swing drying method according to claim 1, characterized in that, Throughout the drying process, the temperature of the drying chamber is between 30°C and 80°C.

Images