JP2016002518A - Adsorption type dehumidifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adsorption type dehumidifier capable of quickly coping with a case of moisture content load variation of a supply destination of dry air, by quickly adjusting humidity of supply air by a simple device.SOLUTION: The present invention is provided with a bypass passage 19 for bypassing a part of dry air coming out of an adsorption zone 8, by supplying the dry air of which has become a low dew point indoors by passing outside air through the adsorption zone 8 of a moisture adsorption rotor 7, a humidifier 21 is arranged in the middle of the bypass passage 19, a humidity sensor 23 is provided in a pipeline which mixes air coming out of the humidifier 21 with air coming out of the adsorption zone 8, and a quantity of air flowing to the bypass passage 19 is adjusted by a solenoid valve 22 in response to output of this humidity sensor 23. Thus, humidity of the air of supplying supply air SA is adjusted by the quantity of air flowed to the bypass passage 19.

Description

  The present invention relates to an adsorption dehumidifier that supplies dry air with low dew point.

  A lithium battery manufacturing plant will cause a problem in the quality of the lithium battery unless it is dehumidified. That is, lithium reacts strongly with moisture, and a lithium battery manufacturing plant needs to set the dew point to -40 degrees Celsius or less (hereinafter, all temperatures are set to "Celsius"). In addition to a lithium battery manufacturing plant, a chemical manufacturing plant or the like may be required to control the dew point in a range of minus 10 degrees to minus 70 degrees. There is a problem that it is difficult to control the dew point within a specific range with such a low dew point. That is, when the dew point is a negative environment, the moisture in the air is extremely small, and thus the dew point changes greatly with the supply of a small amount of moisture. For this reason, control of the supply amount of moisture is important.

  When conducting experiments associated with the manufacture and development of lithium batteries and some chemicals, it is necessary to perform them in a dry room supplied with dry air with a negative dew point. In order to create such a low dew point dry room environment, an adsorption type dehumidifying means using an adsorption rotor having a moisture adsorbent such as silica gel or zeolite is used. In order to control the dew point using such a dehumidifying means, there is a method of controlling the temperature of the regenerated air of the dehumidifying rotor as disclosed in Patent Document 1. Alternatively, as disclosed in Japanese Patent Application Laid-Open No. H10-228707, there is a technique in which the dew point is controlled by controlling the regeneration air volume of the dehumidifying rotor. This is because it is difficult to control the dew point by supplying moisture as described above.

  Lithium battery production lines and chemical production lines are subject to various air condition constraints in order to improve performance and quality. However, when an operator enters and leaves the production line, the moisture load fluctuates due to the entry and exit of the room. Further, the moisture load fluctuates due to the moisture of the material itself sent to the production line and the moisture attached to the outer wall of the container containing the material. The humidity in the dry room changes due to this moisture load fluctuation. Then, it becomes necessary to maintain the humidity in the dry room constant, and means for that is required.

  In the technique disclosed in Patent Document 1, the humidity in the dry room is adjusted by adjusting the dehumidifying capacity by controlling the temperature of the regeneration air of the dehumidifying rotor. Moreover, what was disclosed by patent document 2 is adjusting the humidity in a dry room by controlling the reproduction | regeneration air volume of a dehumidification rotor, adjusting a dehumidification capability.

  What is disclosed in Patent Document 1 is characterized in that when the dehumidifying capacity may be small, the temperature of the regeneration air is lowered, so that energy is saved accordingly. However, the amount of moisture desorbed in the regeneration zone changes when the regeneration temperature is changed, which changes the dehumidification capacity, which takes time to control the dehumidification capacity, and thus takes time to adjust the humidity of the dry room. There is.

  What is disclosed in Patent Document 2 is characterized in that when the dehumidifying capacity may be small, the amount of regeneration air of the dehumidifying rotor is reduced, so that the energy is saved accordingly. However, since the amount of moisture desorbed in the regeneration zone is changed by changing the regeneration air volume, and the dehumidification capacity changes accordingly, it takes time to control the dehumidification capacity, and this example also takes time to adjust the humidity of the dry room. There is a problem that it takes.

JP 2006-162131 A JP 2000-237524 A

  The problem to be solved is a simple device that opens and closes when a person enters and exits a dry room, etc., or quickly absorbs moisture load fluctuations due to the loading of materials, and absorbs less humidity. An object of the present invention is to provide a dehumidifying device.

  The present invention has a precooler that cools the outside air, passes air cooled and dehumidified by the precooler through the adsorption zone of the moisture adsorption rotor, and thereby supplies dry air having a low dew point to the room. A bypass path that bypasses a part of the dry air that has exited is provided, a humidifier is placed in the middle of the bypass path, and a humidity sensor is installed in the pipeline that mixes the air exiting the humidifier and the air exiting the adsorption zone. The main feature is that the amount of air flowing through the bypass is adjusted according to the output of the humidity sensor. As a result, the humidity of the air supplied into the dry room is adjusted by the amount of air flowing through the bypass.

  In the adsorption type dehumidifier of the present invention, a humidifier is arranged in the middle of the bypass path, and because the humidifier has high humidity air in the bypass path, the air in the bypass path and the adsorption zone of the adsorption rotor The humidity of the supply air can be adjusted by mixing with the dry air that has passed through.

  And the air of desired humidity can be obtained by adjusting the mixing ratio of dry air and humidified air. Further, the mixing ratio can be easily adjusted by a valve or the like. When the mixing ratio is adjusted, the humidity immediately changes, so that the response speed of humidity adjustment can be increased. In addition, a humidifier that does not require quick response is not necessary, and the degree of freedom in design is high, so that it can be selected from the viewpoint of cost and durability.

FIG. 1 is a flowchart showing Example 1 of an adsorption dehumidifier. FIG. 2 is a graph showing elapsed time and dew point temperature when dew point control is performed by the adsorption type dehumidifier of Example 1.

  The adsorption type dehumidifier of the present invention is configured to supply dry air that has passed through the adsorption zone of the moisture adsorption rotor and has a low dew point into the room, and has a bypass path that bypasses a part of the dry air that has exited the adsorption zone. A humidifier is installed in the middle of the bypass path, and a humidity sensor is installed in the pipeline that mixes the air that has exited the humidifier and the air that has exited the adsorption zone. By adjusting the amount of air to flow, the humidity of the supply air is adjusted. For this reason, it can respond rapidly to the change of the humidity in a dry room.

  First, a description will be given along FIG. The flow rate of the outside air OA is adjusted by the valve 1, and dust is removed by the first air filter 2. The temperature of the outside air is measured by the temperature sensor 3, cooled by the first precooler 4, and dehumidified by condensation. The temperature of the air exiting the first precooler 4 is measured by the temperature sensor 5. This air flow is created by the fan 6.

  Dehumidification rotor 7 is a known rotor in which silica gel or the like is synthesized on a honeycomb rotor or zeolite is supported. The dehumidifying rotor 7 is divided into an adsorption zone 8, a purge zone 9, and a regeneration zone 10. The dehumidifying rotor 7 is driven to rotate by a geared motor 11. The dry air that has passed through the adsorption zone 8 is heated to a desired temperature by an after heater 12. Contamination is removed from the air whose temperature has been raised by the after heater 12 by the second air filter 13. That is, the adsorbent that has fallen off from the surface of the dehumidifying rotor 7 is removed.

  The air that has passed through the second air filter 13 is branched into two paths, an external supply path 14 and a return path 15. A valve 16 is provided in the return path 15, and thereby the return air volume is set. The return path 15 is provided with a second precooler 17 that lowers the temperature of the air to a predetermined temperature and promotes moisture adsorption in the adsorption zone 8. A temperature sensor 18 is provided on the outlet side of the second precooler 17, whereby the outlet temperature of the second precooler 17 is controlled. Air exiting the second precooler 17 is sucked into the fan 6 and sent to the adsorption zone 8. That is, the cooled outside air and the air returned through the return path 15 are mixed and sent to the adsorption zone 8.

  A part of the air passing through the second air filter 13 and sent to the external supply path 14 is branched to the bypass path 19. The bypass passage 19 is provided with an electromagnetic valve 20, a humidifier 21, and a variable valve 22. The bypass path 19 finally merges with the external supply path 14, and a humidity sensor 23 is provided behind the merge point. The opening degree of the variable valve 22 is controlled according to the detection data of the humidity sensor 23. That is, the mixing ratio of humid air is controlled according to the detection data of the humidity sensor 23. The air that has passed through the humidity sensor 23 is sent to an external dry room (not shown) as supply air SA.

  After leaving the purge zone 9, the air passes through the valve 24, is heated by the regeneration heater 25, and is sent to the regeneration zone 10. The temperature of the air before and after passing through the regeneration zone 10 is measured by temperature sensors 26 and 27. If the difference between the measured values of the temperature sensors 26 and 27 is greater than or equal to a predetermined value, it can be seen that the reproduction zone 10 is sufficiently regenerated. The air that has passed through the regeneration zone 10 is discharged to the outside by the fan 28 as exhaust EA.

  The first embodiment of the present invention is configured as described above, and the operation will be described below. First, the valve 1 is opened, and the first precooler 4, the fan 6, the geared motor 11, the second precooler 17, the regenerative heater 25, and the fan 28 are operated. Thus, the outside air OA is sucked by the fan 6, dust is removed by the first air filter 2, the temperature is measured by the temperature sensor 3, and the first precooler 4 is cooled. With this cooling, the dew point decreases to the temperature of the first precooler 4. That is, it is dehumidified by condensation.

  The temperature of the dehumidified and lowered humidity is measured by the temperature sensor 5 and passes through the adsorption zone 8 of the dehumidifying rotor 7 by the fan 6, and the humidity is further reduced by adsorption. At this time, the dehumidifying rotor 7 is rotated by the geared motor 11. Depending on the temperature measured by the temperature sensor 5, the temperature of the air leaving the adsorption zone 8 rises by the after heater 12 if necessary. The air that has passed through the after heater 12 is separated into the external supply path 14 and the return path 15 by removing the adsorbent that has fallen from the dehumidification rotor 7 by the second air filter 13.

  Here, after cooling with the first precooler 4, heating with the after-heater 12 seems to be useless, but the first precooler 4 is not only cooled but also dehumidified by condensation as described above, and is desired. This is because in order to secure the dehumidification amount and to secure the adsorption amount in the adsorption zone 8 by lowering the temperature, it is required to cool below the temperature desired for the externally supplied air.

  The air branched into the return path 15 has its return air amount determined by the valve 16 and cooled by the second precooler 17, and its temperature is measured by the temperature sensor 18 and mixed with the outside air OA passing through the first precooler 4. Then, it passes through the adsorption zone 8 of the dehumidifying rotor 7 again. By this circulation, the dew point of the supply air SA can be lowered to minus 70 degrees. In addition, you may install the return path 15 so that the air immediately after passing the adsorption | suction zone 8 in front of the after heater 12 may circulate.

  The air exiting the fan 6 is branched to the purge zone 9 where heat is recovered and the purge amount is adjusted by the valve 24, heated by the regeneration heater 25, and sent to the regeneration zone 10. Respective temperatures before and after the air sent to the regeneration zone 10 are measured by the temperature sensor 26 and the temperature sensor 27. If this temperature difference is less than or equal to a predetermined value, it can be seen that the amount of regeneration in the regeneration zone 10 is not secured. In this case, the regeneration amount is secured by raising the temperature of the regeneration heater 25. The humid air leaving the regeneration zone 10 is discharged to the outside as exhaust EA.

  The dry air that has passed through the second air filter 13 and branched to the bypass passage 19 passes through the humidifier 21 when the electromagnetic valve 20 is open. Here, the dry air is humidified and mixed with the dry air that has passed through the after heater 12 and the second air filter 13. The humidity of the mixed air is measured by the humidity sensor 23. When the humidity is lower than a predetermined value, the opening degree of the variable valve 22 is controlled to be increased, and the amount of humidified air is increased and supplied. The humidity of the air SA becomes a desired value. Thus, when the humidity of the supply air SA approaches a predetermined value, the opening degree of the variable valve 22 is controlled to be reduced.

  The variable valve 22 can be freely changed in opening degree by an electric motor, and a commercially available one can be used. Many such variable valves 22 that are operated within one second from the maximum opening to the closing are commercially available. If such a valve is employed, humidity adjustment can be performed within one second. In this way, the humidity adjustment is performed by the variable valve 22 that responds to the output of the humidity sensor 23, so that it can be performed accurately in a very short time.

  As described above, since the humidifier 21 is provided in the bypass passage 19 without providing the humidifier directly in the external supply passage 14, the dew point can be accurately controlled even at a low dew point of a dew point temperature of minus 10 degrees or less. . Further, in this embodiment, by using a vaporizing type humidifying means such as a humidifying filter in the humidifier 21, even with a low dew point supply air having a dew point temperature of minus 10 degrees to minus 70 degrees with a small air volume of about 20 m3 / h, Quick dew point control within 2 degrees above and below the dew point temperature can be performed quickly. Here, when a steam type or ultrasonic type humidifier is used, air with a considerably higher humidity than the supply air is generated immediately after the humidifier is operated, so that dew point control takes time and is not stable. Also, in the case of a small air volume, moisture diffuses from the humidifier side to the supply path side, contrary to the flow of the wind, causing a sudden increase in the dew point of the supply air. Therefore, by using a humidifying filter which is a vaporizing type humidifying means, the humidity of the humidified air also increases / decreases in proportion to the increase / decrease in the amount of air passing through the humidifying filter, so that stable dew point control becomes possible.

  FIG. 2 is a graph showing the relationship between the elapsed time and the dew point temperature when the dew point control is performed by the adsorption dehumidifier of the present invention. In the conventional adsorption type dehumidifier, when the dew point control temperature is lowered from minus 30 degrees to minus 60 degrees, it takes about one hour until the dew point becomes stable. However, in the adsorption type dehumidifier of the present invention, the dew point control temperature is minus. Even if the dew point is lowered from 20 degrees to minus 30 degrees, minus 50 degrees, minus 70 degrees, and low dew point supply air, the dew point can be accurately controlled within 2 degrees above and below the dew point temperature in a short time within 10 minutes.

  As described above, the adsorption type dehumidifier of the present invention measures the humidity of the supply air with the humidity sensor 23, mixes the humidified air accordingly, and performs the mixing ratio with the variable valve 22. Air with good responsiveness and high precision can be supplied.

DESCRIPTION OF SYMBOLS 1 Valve 2 1st air filter 3 Temperature sensor 4 1st precooler 5 Temperature sensor 6 Fan 7 Dehumidification rotor 8 Adsorption zone 9 Purge zone 10 Regeneration zone 11 Geared motor 12 After heater 13 Second air filter 14 External supply path 15 Return path 16 Valve 17 Second precooler 18 Temperature sensor 19 Bypass path 20 Electromagnetic valve 21 Humidifier 22 Variable valve 23 Humidity sensor 24 Valve 25 Regenerative heater 26 Temperature sensor 27 Temperature sensor 28 Fan

Claims (3)

  A first precooler that cools and dehumidifies the outside air, a dehumidification rotor that further dehumidifies the air cooled by the first precooler, a return path that circulates a portion of the air dehumidified by the dehumidification rotor, and air that has been dehumidified by the dehumidification rotor A bypass passage that branches a part of the air passage, a humidifier that humidifies the air in the bypass passage, a humidity sensor that measures the humidity of the air after the humidified bypass passage air and the air dehumidified by the dehumidification rotor are mixed, and And a variable valve that adjusts the amount of air flowing through the bypass passage according to the output of the humidity sensor.   The dehumidification rotor is divided into an adsorption zone, a purge zone, and a regeneration zone, a temperature sensor for measuring the temperature before and after the regeneration zone and a regeneration heater are provided, and the temperature difference before and after the regeneration zone is a predetermined value or less. An adsorption dehumidifier configured to control the temperature of the regenerative heater to be raised due to insufficient regeneration.   The adsorption type dehumidifying device according to claim 1, wherein the humidifier is a vaporizing type humidifying means.

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