JP6138457B2 - Drying room for glove box - Google Patents

Description

A glove box is an experiment where the humidity inside the box is kept extremely low, a hand is inserted through a rubber glove (glove) sealed from the outside of the box, and a dry environment inside the box is used. Is to do. The present invention relates to a glove box that can perform dew point control with high accuracy and can reduce the carbon dioxide concentration of supplied air.

When dehumidifying the air in a specific box, dehumidification by condensation using a refrigerator reduces energy consumption, but it is difficult to reduce the humidity of the air in the box to a negative dew point. It was.

That is, in recent years, development and improvement of lithium ion batteries and lithium ion capacitors have been intensified. Lithium compounds easily adsorb moisture in the air and deteriorate the performance of batteries and capacitors. Therefore, in experiments accompanying these developments, air with extremely low dew point or nitrogen vaporized from liquid nitrogen is used. It is necessary to conduct the experiment in a purged box. In the case of using liquid nitrogen, it is necessary to prepare liquid nitrogen before the experiment. Since the liquid nitrogen is continuously consumed during the experiment, there is a problem that the cost is increased.

In addition, organic EL elements used in organic EL display devices, which are expected as next-generation flat panel displays to replace liquid crystal display devices, are promising for use as solid light-emitting, inexpensive large-area full-color display elements and writing light source arrays. Active research and development is underway. However, organic substances such as organic light-emitting materials used in organic EL elements, electrodes, and the like are weak against moisture and performance and characteristics deteriorate rapidly. Therefore, it is necessary to conduct experiments in a box in which air is purged with air having a very low dew point or nitrogen obtained by vaporizing liquid nitrogen in the experiments accompanying these developments.

Furthermore, in the case of a lithium ion battery, if carbon dioxide is present in the atmosphere, there is a problem that the performance deteriorates as described in Patent Document 1. What is disclosed in this Patent Document 1 is to remove the influence of carbon dioxide in the manufacturing process of an electrode of a lithium ion battery, and air is bubbled into a sodium hydroxide solution as a means for removing carbon dioxide. . However, in the process of completing the lithium ion battery, dry air is required, and bubbling in the solution as a means for removing carbon dioxide causes a problem because the humidity of the air increases.

Moreover, the amine-type thing disclosed by patent document 2 as a carbon dioxide absorber is also what makes a solution absorb a carbon dioxide, and there exists a problem that air is humidified by use.

JP 09-320598 A Japanese Patent Laid-Open No. 06-343858

As described above, those disclosed in Patent Document 1 and Patent Document 2 have a problem that the humidity of the air increases in the process of carbon dioxide adsorption or absorption. It is difficult to employ a device that supplies dry air having a dew point of minus 10 degrees to minus 80 degrees as in the present invention.

The present invention has been made to solve the above-described problems, and an object thereof is to provide a glove box that can remove carbon dioxide contained in dry air, lower the concentration of carbon dioxide, and lower the dew point. And

The present invention divides the dehumidification rotor into an adsorption zone, a purge zone, and a regeneration zone with respect to the rotation direction, and provides a regeneration circulation path through which air passing through the regeneration zone circulates again. The mixture is cooled after being mixed with a carbon dioxide absorption canister filled with a carbon dioxide absorbent composed of an alkali metal hydroxide or an alkaline earth metal hydroxide, and then passed through an adsorption zone for adsorption. The most important feature is that the air that has passed through the zone is supplied to the drying chamber and is put into a cooling device via a return air valve so that the cooled dry air is returned to the adsorption zone 2 again.

The glove box of the present invention circulates the air passing through the regeneration zone of the dehumidification rotor, mixes a part thereof with the outside air, cools it, and passes the air having a higher relative humidity through the carbon dioxide adsorption canister. Therefore, the carbon dioxide adsorption action is strong, and the carbon dioxide concentration in the drying chamber can be lowered.

Further, since the air passing through the regeneration zone of the dehumidifying rotor is circulated, there is little waste of energy. Furthermore, this circulation reduces the amount of exhaust, and thus the glove box of the present invention can be easily installed inside a clean room. Furthermore, this circulation requires less energy to be applied to the regenerative heater and extends the life of the regenerative heater.

Further, the humidity adjustment in the drying chamber is performed by the bypass of the adsorption zone and the bypass of the drying chamber, so that the humidity adjustment is highly responsive and is generally suitable as a humidity adjusting means for a glove box having a small volume.

FIG. 1 is a flowchart showing an embodiment of the glove box of the present invention.

In the present invention, the dehumidification rotor is divided into an adsorption zone, a regeneration zone, and a purge zone with respect to the rotation direction, and after mixing the outside air and a part of the regenerated circulation air, the air is cooled and the relative humidity is increased. The dew point in the glove box is provided by providing a bypass route with a flow control device that allows the carbon dioxide absorption canister filled with the carbon dioxide absorbent to pass through the adsorption zone and the upstream and downstream sides of the adsorption zone. By combining regeneration temperature proportional control and rotor bypass flow rate control using the bypass path, a glove box is provided that allows precise dew point control with low energy consumption and lowers the carbon dioxide concentration in the box. Realized the purpose of doing.

Hereinafter, it demonstrates along FIG. 1 which shows the Example of this invention. Reference numeral 1 denotes a dehumidifying rotor, which carries a moisture adsorbent such as silica gel or zeolite and has a honeycomb rotor shape. The dehumidifying rotor 1 is rotated by a motor (GM), and is divided into zones according to the rotation direction as follows. All temperatures used in the following description are in degrees Celsius.

That is, reference numeral 2 denotes an adsorption zone, where moisture in the air is adsorbed by the dehumidifying rotor 1. 3 is a purge zone, and 4 is a regeneration zone. The adsorbed moisture is desorbed from the dehumidifying rotor 1 by the high-temperature air passing through the regeneration zone 4. An intake valve 5 controls the amount of outside air OA introduced and whether the outside air OA is introduced or not is controlled by opening and closing. A filter 6 removes dust contained in the outside air.

Reference numeral 7 denotes a precooler, which cools the passing air with a refrigerant sent from a refrigeration compressor (not shown). Reference numerals 8 and 9 denote temperature sensors. The temperature sensor 8 detects the temperature of the air before entering the precooler 7, and the temperature sensor 9 detects the temperature of the air that has exited the precooler 7.

A carbon dioxide absorption canister 10 absorbs and removes carbon dioxide from the air cooled by the precooler 7. The carbon dioxide absorption canister 10 is filled with sodium hydroxide pellets and silica gel pellets in a mixed state. That is, sodium hydroxide reacts with carbon dioxide to become sodium hydrogen carbonate. Sodium hydroxide pellets are deliquescent due to moisture in the air, but the deliquescent action is prevented because the silica gel pellets are mixed. Instead of silica gel pellets, activated alumina pellets, activated carbon, sepiolite, zeolite or calcium hydroxide pellets may be mixed. When the phenolphthalein powder is mixed with these pellets, the color of the light purple is initially light, but the color becomes lighter as sodium hydrogen carbonate is produced.

Reference numeral 11 denotes an adsorption blower that sends the air cooled by the first precooler 7 to the adsorption zone 2. Reference numeral 12 denotes a bypass passage that bypasses the front and back of the adsorption zone 2, and the bypass passage 12 is provided with an electric valve 13 that adjusts the amount of bypass.

Reference numeral 14 denotes an after heater, which heats when the temperature of the dry air that has passed through the adsorption zone 2 is too low. Reference numeral 15 denotes a post filter, which purifies the air supplied to the drying chamber 16. Reference numeral 17 denotes a supply valve that adjusts the amount of dry air sent to the drying chamber 16. Reference numeral 18 denotes a return air valve that adjusts the amount of air that has passed through the rear filter 15 to be returned to the suction side of the adsorption blower 11. Reference numeral 19 denotes a return valve that adjusts the amount of return air from the drying chamber 16. The amount of air passing through the drying chamber 16 is adjusted by the supply valve 17 and the return valve 19. Since the drying chamber 16 is not hermetically sealed but has local exhaust, it is necessary to adjust the amount of air passing through the two valves.

20 is a temperature sensor that detects the temperature of the drying chamber 16, and 21 is a humidity sensor that detects the humidity of the drying chamber 16. Reference numeral 22 denotes a second precooler that cools the dry air that has passed through the return air valve 18, and the dry air cooled thereby is sucked into the adsorption blower 11. Reference numeral 23 denotes a temperature sensor that measures the temperature of the air that has exited the second precooler 22.

A purge valve 24 adjusts the amount of air passing through the purge zone 3, and the air that has passed through the purge valve 24 enters the regeneration heater 25. A temperature sensor 26 measures the temperature of the air that has exited the regeneration heater 25, and a temperature sensor 27 measures the temperature of the air that has exited the regeneration zone 4.

Reference numeral 28 denotes a regeneration blower that sucks out air from the regeneration zone 4, and an outlet of the regeneration blower 28 is connected to a regeneration circulation valve 29 and a regeneration return valve 30. The regeneration circulation valve 29 adjusts the circulation amount of the regeneration air that leaves the regeneration zone 4 and returns to the regeneration heater 25. The regeneration return valve 30 adjusts the amount of air that returns the air exiting the regeneration zone 4 to the front of the filter 6, that is, to the front of the first precooler 7. The amount of exhaust (EA) discharged to the outside is determined by the opening degree of the regeneration return valve 30 and the intake valve 5. In addition, it is good also as a structure which eliminates exhaust_gas | exhaustion (EA) and returns before the whole quantity filter 6.

The glove box of this invention consists of said structure, and demonstrates the operation | movement below. First, dust or the like is removed from the outside air (OA) by the filter 6, cooled by the precooler 7, and condensed and dehumidified. The relative humidity of the air leaving the precooler 7 becomes almost 100% and enters the carbon dioxide absorption canister 10. The carbon dioxide absorption canister 10 is filled with sodium hydroxide pellets and silica gel pellets in a mixed state as described above, and the sodium hydroxide reacts with carbon dioxide to become sodium hydrogen carbonate. This removes carbon dioxide.

The air from which carbon dioxide has been removed is pressurized by the adsorption blower 11 and passes through the adsorption zone 2. In the course of this passage, moisture in the air is adsorbed by the dehumidifying rotor 1 and becomes dry air. The dry air is heated by the after heater 14 until it reaches an appropriate temperature, that is, an appropriate temperature as air supplied to the drying chamber 16.

The dry air thus produced is finally removed from the dust by the rear filter 15, the supply amount is adjusted by the supply valve 17, and the dry air is supplied to the drying chamber 16. Here, when the humidity in the drying chamber 16 is lower than the target humidity, the detection signal of the humidity sensor 21 is sent to the electric valve 13, the electric valve 13 is opened, and the adsorption zone 2 of the dehumidifying rotor 1 is bypassed. The amount of dehumidification is reduced, and the humidity becomes appropriate and is supplied to the drying chamber 16.

The air that has left the drying chamber 16 is adjusted in return air amount by the return valve 19, passes through the precooler 22, is cooled, and enters the adsorption blower 11 again. In this way, the air in the drying chamber 16 is dehumidified while circulating. For this reason, even if there is a substance that generates moisture in the drying chamber 16, that is, a humidity load, the humidity in the drying chamber 16 is maintained below a predetermined value.

Here, as a means for adjusting the humidity in the drying chamber 16, an amount of air passing through the bypass passage 12 and a passage bypassing the drying chamber 16 by the return air valve 18 are configured. According to this humidity adjusting means, the response of humidity adjustment to the humidity change in the drying chamber 16 becomes faster. In other words, the glove box is originally provided with a small drying chamber, and an experiment or the like is performed inside the drying chamber 16 through a glove (glove) from the outside. Since the volume of the drying chamber 16 is small, the humidity adjustment means. Responsiveness is questioned.

Part of the air that has exited the adsorption blower 11 passes through the purge zone 3 to cool the dehumidification rotor 1 and recover heat from the dehumidification rotor 1. The amount of air passing through the purge zone 3 is adjusted by the purge valve 24. In addition, the circulation amount of the air passing through the regeneration zone 4 is adjusted by the regeneration circulation valve 29 and returns to the regeneration zone 4 again. This is because when the humidity load in the drying chamber 16 is small, the humidity of the air that has passed through the regeneration zone 4 increases little and can be circulated for use.

The air that has passed through the regeneration zone 4 and entered the precooler 7 has a lower absolute humidity than the outside air OA when not immediately after operation. That is, when the dew point of the drying chamber 16 is minus 80 degrees, the amount of moisture adsorbed on the dehumidifying rotor 1 is small and the moisture desorbed in the regeneration zone 4 is also small. Therefore, the humidity is lower than that of the outside air OA, and the energy consumption is less when it is returned to the adsorption zone 2 and used again. Further, the amount of exhaust EA is reduced, and the glove box of the present invention is easy to install and use in a clean room.

Thus, since the air that has left the drying chamber 16 passes through the regeneration zone 4 and returns to the carbon dioxide absorption canister 10 again, the concentration of carbon dioxide in the drying chamber 16 gradually decreases. Here, since the air returning from the drying chamber 16 to the adsorption blower 11 has low humidity, the carbon dioxide removal effect in the carbon dioxide absorption canister 10 is small. For this reason, this air does not pass through the carbon dioxide absorption canister 10 but directly returns to the adsorption blower 11.

In the above embodiment, a mixed example of sodium hydroxide and silica gel was shown as the absorbent filled in the carbon dioxide absorption canister 10; however, sodium hydroxide may be mixed with other alkali metal hydroxides such as potassium metal and lithium metal. But it ’s okay. Further, instead of silica gel, hydrophilic activated carbon, activated alumina, sepiolite, zeolite, or calcium hydroxide may be used. Alternatively, the same effect can be obtained by impregnating them with an alkali metal hydroxide.

Since the canister 10 is provided after the precooler 7, the air is cooled and the relative humidity is increased. When the relative air humidity at the inlet of the canister 10 is 90% or more, an absorbent with an alkali metal hydroxide may cause a problem. In other words, alkali metal hydroxide deliquesces by moisture absorption, and the amount of moisture absorption increases rapidly at high relative humidity, and when the relative humidity is 90% RH or more, the deliquescent and moisture absorption solution flows out and the carbon dioxide absorption performance decreases or the absorption that flows out. There is a disadvantage that the agent corrodes the peripheral equipment on the downstream side. In such a case, if a layer of pellets such as silica gel, activated carbon, activated alumina, sepiolite, zeolite, calcium hydroxide or the like, which does not contain alkali metal hydroxide, is provided on the downstream side of the canister 10, the outflow of the absorbing solution Can be prevented.

When the relative humidity is high, the same effect can be obtained by using an alkaline earth metal hydroxide such as a calcium hydroxide powder molded product instead of the alkali metal hydroxide as the carbon dioxide absorbent. In this case, calcium hydroxide combines with carbon dioxide to form calcium carbonate, but this reaction also requires moisture. That is, the alkali metal hydroxide easily binds to carbon dioxide in the presence of moisture, so that the performance is improved at a high relative humidity and can be used even at a relative humidity of 90% or more. In this case, there is no deliquescence action and there is no need to put a moisture adsorbent such as silica gel into the canister 10.

Further, when the relative humidity is high, an absorbent containing an alkali metal hydroxide is filled on the air inlet side, and an absorbent or adsorbent layer not containing an alkali metal hydroxide is provided on the outlet side. A carbon dioxide absorbent can be placed in the canister 10. Thus, carbon dioxide can be strongly absorbed by the alkali metal hydroxide on the inlet side. And even if this is deliquescent, the dehydrated alkali metal hydroxide is prevented from flowing out by the layer of the absorbent or adsorbent which does not contain the alkali metal hydroxide on the outlet side. Furthermore, the alkali metal hydroxide deliquescence, which has been prevented from flowing out, combines with carbon dioxide to become a hydrogen carbonate compound, thereby eliminating the deliquescent action. For this reason, the absorbent or adsorbent layer that does not contain alkali metal hydroxide on the outlet side has a thickness that blocks the total amount of solution formed by deliquescence by the absorbent containing alkali metal hydroxide on the inlet side. It does not have to be.

As described above, the present invention can provide a glove box that can keep the carbon dioxide concentration in the drying chamber low.

DESCRIPTION OF SYMBOLS 1 Dehumidification rotor 2 Adsorption zone 3 Purge zone 4 Regeneration zone 5 Intake valve 6 Filter 7 Precooler 8 Temperature sensor 9 Temperature sensor 10 Carbon dioxide absorption canister 11 Adsorption blower 12 Bypass path 13 Electric valve 14 After heater 15 Rear filter 16 Drying chamber 17 Supply Valve 18 Return air valve 19 Return valve 20 Temperature sensor 21 Humidity sensor 22 Precooler 23 Temperature sensor 24 Purge valve 25 Regenerative heater 26 Temperature sensor 27 Temperature sensor 28 Regenerative blower 29 Regenerative circulation valve 30 Regenerative return valve

Claims (2)

It is those obtaining Bei dehumidifying rotor having a moisture adsorbent, dehumidification rotor this is divided into at least adsorption zone purge zone and regeneration zone, a part of the air that has passed through the regeneration zone through regeneration recycle valve Circulate through the regeneration zone, the remaining air is mixed with the outside air through the regeneration return valve, passes through the cooling device, and the air passing through the cooling device passes through the carbon dioxide absorption canister filled with alkali metal hydroxide. Then, the air that has passed through the carbon dioxide absorption canister passes through an adsorption zone provided with a bypass passage having an electric valve of the dehumidifying rotor, and the air that has exited the adsorption zone passes through a supply valve and passes through a drying chamber and a return air. so as to through the valve passes through the bypass passage of the drying chamber, the adsorption zone of the dehumidification rotor return air of this drying chamber or found through return valve Drying room glove box being characterized in that the back. It is those obtaining Bei dehumidifying rotor having a moisture adsorbent, dehumidification rotor this is divided into at least adsorption zone purge zone and regeneration zone, a part of the air that has passed through the regeneration zone through regeneration recycle valve The carbon dioxide absorption canister is circulated through the regeneration zone, the remaining air passes through the regeneration return valve, is mixed with the outside air, passes through the cooling device, and the air passing through the cooling device is filled with an alkaline earth metal hydroxide. The air passing through the carbon dioxide absorption canister passes through an adsorption zone provided with a bypass passage having an electric valve of the dehumidification rotor, and the air exiting the adsorption zone passes through a supply valve to the drying chamber and return air as through the valve passes through the bypass passage of the drying chamber, the suction zone of the dehumidification rotor return air of this drying chamber or found through return valve Drying room glove box, characterized in that it has returned to the emissions.

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