Drying system

Abstract

To provide a drying system capable of raising the temperature of air to a drying temperature without requiring a backup such as an electric heater even in winter.SOLUTION: A drying system 1 comprises a hot air generation device 10 that raises the temperature of air by allowing air to flow through a gas cooler to exchange heat with a cooling medium, an air supply fan 20 that supplies the hot air generation device with air, and an exhaust fan 40 exhausting air outside, which air has been used in a drying chamber 30 where drying is carried out using air whose temperature is raised by the hot air generation device. The air supply fan and the exhaust fan communicate with each other via a damper 50 whose opening is adjustable.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a drying system.

Background Art

[0002] Conventionally, in order to dry wood, marine products, industrial products, etc., it has been known to dry using hot air. Examples of methods for generating warm air include an electric heater and a steam heater. However, when using an electric heater or a steam heater, it takes time to raise the temperature to a predetermined temperature, which is not preferable.

[0003] In relation to this, for example, in Patent Document 1 below, a hot air generating device is disclosed that constitutes a heat pump cycle using CO2 as a refrigerant, and ventilates air through a gas cooler to raise the temperature by heat exchange with the refrigerant to generate hot air.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The above-described hot air generating device is generally designed to be able to raise the temperature of the outside air temperature in summer (for example, 30°C) to the drying temperature (for example, 90°C). For this reason, in winter when the outside air temperature is low (for example, 0°C), the hot air generating device alone does not have sufficient ability to heat up to the drying temperature, and backup such as an electric heater is required.

[0006] The present invention was invented to solve the above problems, and an object thereof is to provide a drying system that does not require backup such as an electric heater even in winter and can raise the temperature to the drying temperature.

Means for Solving the Problems

[0007] The drying system for achieving the above object includes a hot air generator that heats air by heat exchange with a refrigerant by ventilating air through a gas cooler, an air supply blower that supplies the air to the hot air generator, and an exhaust blower that exhausts the air used in a drying chamber where drying is performed by the air heated by the hot air generator to the outside. The control unit, It has. The air supply blower and the exhaust blower communicate with each other via dampers whose openings can be adjusted. The control unit controls the opening degree of the damper based on the temperature of the air supplied from the air supply blower.

Advantages of the Invention

[0008] According to the drying system configured as described above, by adjusting the opening degree of the damper based on the temperature of the air supplied from the air supply blower to the hot air generator in winter, the relatively high-temperature air exhausted from the exhaust blower can be sent to the air supply blower. Then, by mixing the air from the exhaust blower 40 with the outside air, the air supplied to the hot air generator can be heated, and air at approximately the same temperature as in summer can be supplied to the hot air generator. Therefore, it is possible to provide a drying system that does not require backup such as an electric heater even in winter and can raise the temperature to the drying temperature.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0010] Embodiments of the present invention will be described with reference to FIG. 1. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant descriptions are omitted. The dimensional ratios in the drawings are exaggerated for convenience of explanation and may be different from the actual ratios.

[0011] FIG. 1 is a schematic diagram showing a drying system 1 according to the present embodiment. The drying system 1 according to the present embodiment can dry, for example, wood, marine products, industrial products, etc.

[0012] As shown in FIG. 1, the drying system 1 according to the present embodiment includes a hot air generator 10, an air supply blower 20 that supplies air to the hot air generator 10, a drying chamber 30 where drying is performed, an exhaust blower 40 that discharges air to the outside, a damper 50 disposed between the air supply blower 20 and the exhaust blower 40, and a control unit 90 that controls the opening degree of the damper 50.

[0013] The hot air generator 10 constitutes a heat pump cycle using CO2 as a refrigerant, and ventilates air through a gas cooler to raise the temperature of the air by heat exchange with the refrigerant. The hot air generator 10 can raise the temperature of, for example, 30°C air supplied from the air supply blower 20 to 80 - 90°C. As the hot air generator 10, the hot air generator 10 disclosed in JP-A-2010-281553 can be used.

[0014] The air supply blower 20 supplies air to the hot air generator 10. A known air supply blower 20 can be used. A first communication path 21 is disposed between the air supply blower 20 and the hot air generator 10. A thermometer 70 is disposed in the first communication path 21. The thermometer 70 measures the temperature of the air passing through the first communication path 21.

[0015] Drying is performed inside the drying chamber 30. The drying chamber 30 is covered with a heat insulating material. In the drying chamber 30, drying is performed with warm air at, for example, 80 - 90°C. A second communication path 31 is disposed between the drying chamber 30 and the hot air generator 10.

[0016] The exhaust blower 40 discharges the air used in the drying chamber 30 to the outside. Since the exhaust blower 40 discharges the air to the outside in this way, it is possible to prevent the pressure in the drying chamber 30 from rising unintentionally.

[0017] The air supply blower 20 and the exhaust blower 40 are configured as an integrated type as shown in FIG. 1. According to this configuration, the entire device can be simplified. A third communication passage 41 is arranged between the exhaust blower 40 and the drying chamber 30.

[0018] The damper 50 is arranged between the air supply blower 20 and the exhaust blower 40 as shown in FIG. 1. The opening degree of the damper 50 is adjusted by the control unit 90. When the damper 50 opens, the relatively high-temperature air exhausted from the exhaust blower 40 can be sent to the air supply blower 20. Also, by closing the damper 50, the communication between the air supply blower 20 and the exhaust blower 40 can be stopped.

[0019] The control unit 90 controls the opening degree of the damper 50 based on the temperature of the air passing through the first communication passage 21 measured by the thermometer 70. The control unit 90 is, for example, a CPU.

[0020] Next, the operation method of the drying system 1 according to the present embodiment will be described.

[0021] First, the operation method in summer will be described. In summer, since the outside air temperature is high (for example, 30°C), the control unit 90 drives the hot air generator 10 with the damper 50 closed, so that the temperature in the drying chamber 30 can be raised to a predetermined drying temperature (for example, 80 - 90°C).

[0022] In summer, when the outside air of 30°C / 70%RH is supplied to the hot air generator 10, the hot air generator 10 can generate hot air of 80°C / 6.3%RH.

[0023] Next, the operation method in winter will be described. In winter, since the outside air temperature is low (for example, 0°C), the control unit 90 drives the hot air generator 10 with the damper 50 open to raise the temperature in the drying chamber 30 to a predetermined drying temperature (for example, 90°C).

[0024] Specifically, the control unit 90 adjusts the opening degree of the damper 50 based on the temperature of the air passing through the first communication passage 21 measured by the thermometer 70. In winter, when the temperature is relatively high, the control unit 90 reduces the opening degree of the damper 50, and when the temperature is relatively low, the control unit 90 increases the opening degree of the damper 50. As a result, the relatively high-temperature air exhausted from the exhaust blower 40 can be sent to the supply blower 20 as appropriate. Then, by mixing the air from the exhaust blower 40 with the outside air, the air supplied to the hot air generator 10 can be heated, and air at approximately the same temperature as in summer can be supplied to the hot air generator 10. Therefore, the hot air generator 10 only needs to always exhibit the same heating capacity.

[0025] In winter, when air at 60°C / 10%RH is mixed from the exhaust blower 40 with outside air at 0°C / 70%RH, air at 30°C / 29%RH is generated and taken into the hot air generator 10, and hot air at 80°C / 2.6%RH can be generated in the hot air generator 10. Thus, in winter, air drier than in summer can be supplied.

[0026] Here, as shown in FIG. 2, in the case of the drying system 900 where the supply blower 20 and the exhaust blower 40 are not in communication with each other as a proportional example, since the air from the exhaust blower 40 is discharged to the outside, in winter when the outside air temperature is low (for example, 0°C), the hot air generator 10 alone does not have sufficient heating capacity to reach the drying temperature, and backup of the electric heater H is required.

[0027] On the other hand, according to the drying system 1 according to the present embodiment, backup such as an electric heater is not required even in winter, and the temperature can be raised to the drying temperature.

[0028] Here, the exhaust air from the exhaust blower 40 is discharged in a state of high absolute humidity. However, since the outside air temperature and absolute humidity are lower in winter than in summer when mixing the exhaust air from the exhaust blower 40 with the outside air, it is less likely that both the temperature and relative humidity of the mixed air will be higher compared to summer. In addition, in order to surely prevent both the temperature and relative humidity of the mixed air from becoming higher compared to summer, it is preferable that a humidity meter is installed together with the thermometer 70, and the control unit 90 performs control so that the absolute humidity of the mixed air does not exceed the design conditions.

[0029] As described above, the drying system 1 according to the present embodiment includes a hot air generator 10 that heats air by heat exchange with a refrigerant by ventilating air through a gas cooler, an air supply blower 20 that supplies air to the hot air generator 10, and an exhaust blower 40 that discharges to the outside the air used in the drying chamber 30 where drying is performed by the air heated by the hot air generator 10. The air supply blower 20 and the exhaust blower 40 communicate with each other via a damper 50 whose opening degree is adjustable. According to the drying system 1 configured in this way, by adjusting the opening degree of the damper 50 based on the temperature of the air supplied from the air supply blower 20 to the hot air generator 10 in winter, relatively high-temperature air exhausted from the exhaust blower 40 can be sent to the air supply blower 20. Then, by mixing the air from the exhaust blower 40 with the outside air, the air supplied to the hot air generator 10 can be heated, and air at approximately the same temperature as in summer can be supplied to the hot air generator 10. Therefore, it is possible to provide a drying system 1 that does not require backup such as an electric heater even in winter and can raise the temperature to the drying temperature.

[0030] In addition, the air supply blower 20 and the exhaust blower 40 are configured as an integral type. According to the drying system 1 configured in this way, the entire system can be simplified.

[0031] Note that the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims.

[0032] For example, in the above-described embodiment, the supply blower 20 and the exhaust blower 40 were configured as an integrated unit. However, as shown in FIG. 3, in the drying system 2, the supply blower 20 and the exhaust blower 40 may be configured separately. At this time, a communication path 60 is arranged between the supply blower 20 and the exhaust blower 40, and a damper 50 is arranged at a location connecting the communication path 60 and the space on the inlet side of the supply blower 20.

Explanation of Signs

[0033] 1, 2 Drying systems, 10 Hot air generator, 20 Supply blower, 30 Drying chamber, 40 Exhaust blower, 50 Damper, 60 Communication path.

Claims

1. A hot air generating device that ventilates air through a gas cooler and heats up the air by heat exchange with a refrigerant; An air supply blower that supplies the air to the hot air generating device; An exhaust blower that discharges the air used in a drying chamber where drying is performed by the air heated by the hot air generating device to the outside; A control unit; and has The air supply blower and the exhaust blower communicate with each other via dampers whose openings can be adjusted, The control unit controls the opening of the damper based on the temperature of the air supplied from the air supply blower. A drying system.

2. The drying system according to claim 1, wherein the air supply blower and the exhaust blower are configured as an integral type.

3. The air supply blower and the exhaust blower are configured separately, A communication path is arranged so as to connect the spaces where the air supply blower and the exhaust blower are arranged, The drying system according to claim 1, wherein the damper is arranged at a location connecting the communication path and the space where the air supply blower is arranged.

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