JPH0454851B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to electrical and electronic equipment, precision equipment, their parts and semi-finished products, elements, chemicals, and various other products that are extremely sensitive to humidity and pollution. It relates to a device for storing (or drying during storage) semi-finished products in a clean dry space.

[Conventional technology]

With the recent development of industrial technology, there has been an increasing demand for clean dry chambers for storing semi-finished products or finished products in a particularly clean environment for a predetermined period during or after the production process. A clean dry chamber that not only provides a clean environment but also protects the product from moisture by maintaining air at a low dew point temperature within the chamber, and in some cases can dry the product during this time. There has been a strong desire to improve the performance of

Conventionally, in order to form such a clean dry chamber, the air supplied to the chamber is purified by passing through a high-performance filter (hereinafter referred to as a HEPA filter), or an inert gas such as nitrogen gas is used to purify the air. Methods such as blowing are adopted, and the state of the airflow is controlled,
Special innovations were made to the shape of the chamber. In addition, to form a clean dry chamber, it is necessary to obtain dry air.
A common method for this purpose was to remove moisture from the air by using chemical hygroscopic agents. That is, it has been common practice to produce dehumidified air using a dehumidifier (dry type or wet type dehumidifier) using a chemical moisture absorbent such as LiCl, and to blow this air into the chamber.

[Problem to be solved by the invention]

The above-mentioned inert gas blowing method has the problem of limited moisture removal and high running costs.Also, when dry air is produced using a chemical moisture absorbent, the chamber is damaged due to carryover of the moisture absorbent. There is a problem in that the quality of the products stored inside may be compromised. The present invention is first aimed at solving these problems inherent in conventional treatments.

Furthermore, there are problems in maintaining indoor cleanliness and humidity due to the effects of contamination from the surroundings and moisture entering when products are taken in and out of storage. If instead of using a moisture absorbent to obtain air with a low dew point temperature, a so-called cooling dehumidification method is used, in which moisture is condensed and removed by cooling the air to a low temperature. There is a problem that frost forms in the cooler, making permanent operation impossible, and a problem that it takes time to start up. Secondly, the present invention attempts to solve this problem.

[Means for solving problems]

As shown in the drawings, the present invention provides a product storage 1
An air blowing nozzle 2 for forming an air curtain is provided at the entrance/exit of the product storage 1, and an air circulation path 4 is provided for recirculating the air in the product storage 1 to the product storage 1 by a blower 3. on the road
A clean dry chamber 6 with a HEPA filter 5 interposed therein; an air dehumidifier 7 for supplying dry air to the clean dry chamber 6; an air dehumidifier 7 connected to the air dehumidifier 7 in a switchable manner, and a dry air discharge pipe 9 of the air dehumidifier 7 is connected to the air blowing nozzle 2 through the air supply pipe 10 via the HEPA filter 5'. The present invention provides an apparatus characterized in that the air dehumidifier 7 has an air supply path structure that allows each of the plurality of air coolers 8 in the air dehumidifier 7 to be switched between a cooling dehumidifying operation and a defrosting operation. , thereby solving the above problem.

The structure and operation of the apparatus of the present invention will be specifically explained below with reference to the drawings.

The clean dry chamber 6 has an entrance/exit door 11
It is a closed space with a closed space, and is kept substantially airtight from the outside atmosphere unless the entrance/exit door 11 is opened.
The inside of this clean dry chamber 6 is further divided into a storage 1 and an air circulation path 4.

The storage 1 is a product storage room provided facing the entrance/exit door 11 of the clean dry chamber 6.
The bottom part has a shelf board 12 through which air freely passes.
Additionally, a HEPA filter 5 is installed on the ceiling. On the ceiling facing the entrance/exit door 11, there is an air blowing nozzle 2 for forming an air curtain.
is provided. Products are stored on the shelf board 12.

The air circulation path 4 is an air path that extends from the floor of the storage 1 (the space below the shelf board 12) to the ceiling of the storage 1 (the space above the HEPA filter 5), and the blower 3 is installed in this path. It has been done. By driving this blower 3, the air in the storage 1 is circulated through the air circulation path 4 into the storage 1, but at this time, it is purified by passing through the HEPA filter 5. be done.

Dry air is supplied from outside the chamber to the clean dry chamber 6 configured to forcibly circulate the air inside the chamber and purify the air at the same time.
The air is supplied from an air blowing nozzle 2 provided above the air curtain 1 for forming an air curtain. The dry air blown from this air blowing nozzle 2 is supplied to the entrance/exit door 11.
While forming an air curtain sufficient to cover the area of , the air enters the air passage 4 and becomes circulating air.

On the other hand, in the apparatus of the present invention, the dry air supplied to the air blowing nozzle 2 is produced by a special air dehumidifier 7 that is configured to perform both a cooling and dehumidifying operation and a dehumidifying operation.

The air dehumidifier 7 has a structure in which a plurality of mutually independent air coolers 8 are connected in a predetermined relationship between an air (outside air) intake port 14 and a dry air discharge pipe 9. FIG. 1 shows a connection relationship between two systems in which an air cooler 8, a refrigerator 15, and a blower 16 are configured based on the same air passage structure. In the drawings, equipment in one system is labeled a, and equipment in the other system is labeled b, but the contents of both are the same. That is, the air cooler 8 is a Finch-Hube heat exchanger through which a refrigerant flows, and the refrigerant is supplied in circulation from the refrigerator 15. This air cooler 8 has the ability to temporarily cool and dehumidify all the outside air over a year to air with a dew point temperature of -50°C.

Each system is connected at a confluence point 17 on the downstream side of the air cooler 8 and communicates with the dry air discharge pipe 9, but each system has the same air supply path structure and can operate independently of each other. To explain this specifically, in each system, a blower 16 and an air cooler 8 are interposed in the main air passage 18 from the air intake port 14 to the confluence point 17. Between the air cooler 8 and the confluence point 17, an exhaust passage 20 leading to the exhaust port 19 is branched off, and from the middle of this exhaust passage 20, a letane passage 20 is connected to the main air supply passage 18 on the suction side of the blower 16.
1 is connected. In addition, a switching damper 22 is installed in the main air supply path 18 near the confluence point 17, an exhaust damper 23 is installed in the exhaust path, a retan damper 24 is installed in the retan path 21, and an intake damper 25 is installed in the air intake port. has been done. The opening degree of each of these dampers can be freely adjusted and the air supply can be completely shut off. By configuring each system in this way and connecting them at the confluence point 17, dehumidifying operation and defrosting operation can be switched alternately, and closed operation for preparatory operation can also be performed. This means that a constant supply of dry air is always available.

This driving operation will be explained next.

First, when one system A opens the switching damper 22a and performs dehumidification operation, the other system B closes the switching damper 22b and stops operation, or performs defrosting operation or preparatory operation. implement.
That is, in system A, the exhaust damper 23a and the retan damper 24a are closed, and dry air dehumidified by the air cooler 8 is supplied to the discharge pipe 9. At that time, in system B, the switching damper 22b is closed, the exhaust damper 23b is opened, and the retan damper 24b is closed to perform defrosting operation, or the switching damper 22b is closed,
The exhaust damper 23b is closed, the retan damper 24b is opened, and the intake damper 25b is closed to perform preparatory operation or to suspend operation. During defrosting operation,
While the flow of refrigerant from the refrigerator 15b to the air cooler 8 is stopped, the blower 16b is driven to circulate hot gas to remove frost deposited on the surface of the air cooler 8, and the exhaust air is It is discharged from the system through the port 18b. This is a preparatory operation to prepare for start-up when switching the system, and is an operation that allows dry air to be supplied immediately at start-up and shortens the start-up time. This is an operation that repeats circulation in a closed circuit. This fills the system with dry air and prepares for system switching.

Next, when frost occurs in the air cooler 8 of system A and its function begins to deteriorate, it is switched to system B, which is in preparatory operation (the switching damper 22a is closed and the switching damper 2b is switched to open). Switching from preparatory operation to dehumidification operation in system B is performed using the retan damper 24.
This is done by closing the damper 25b and opening the intake damper 25b. In the system A, during the dehumidifying operation of the system B, defrosting operation, suspension, and preparatory operation are appropriately carried out in the same way as described above to prepare for the next switching.

By this switching, dry air is continuously and constantly supplied to the clean dry chamber 6.

As described above, according to the device of the present invention, dry air can be produced without using a moisture absorbent, so the problem of product quality deterioration caused by a moisture absorbent is avoided, and the dew point temperature can be reduced to −50% despite the cooling dehumidification method.
This allows continuous supply of dry air at temperatures around ℃. At the time of switching, a preparatory operation is performed in addition to the defrosting operation to prepare for the dehumidifying operation, thereby reducing operating costs and ensuring a constant continuous supply of dry air. In addition, in the clean dry chamber, a clean dry air atmosphere is maintained at all times through the circulation of dry air, and even when products are taken in and out, contamination from the outside atmosphere and moisture due to intrusion of outside air are absorbed by the dry air curtain. This can be effectively prevented by

[Brief explanation of drawings]

FIG. 1 is an equipment layout system diagram showing an embodiment of the apparatus of the present invention. 1...Storage, 2...Air blowing nozzle, 3...
Blower, 4...Air circulation path, 5,5'...HEPA
Filter, 6...Clean dry chamber,
7... Air dehumidifier, 8... Air cooler, 9...
Dry air discharge pipe, 11... Entrance/exit, 12... Shelf board, 14... Air intake port, 15... Refrigerator, 16
...Blower, 17...Confluence point, 19...Exhaust port,
21...Retan duct, 22...Switching damper.

Claims (1)

[Claims] 1. An air blowing nozzle 2 for forming an air curtain is provided at the entrance/exit of the product storage 1, and the air inside the product storage 1 is recirculated to the product storage 1 by a blower 3. A clean dry chamber 6 is provided with an air circulation path 4 and a HEPA filter 5 is interposed in the air circulation path, and an air dehumidifier 7 for supplying dry air to the clean dry chamber 6, an air dehumidifier 7 in which a plurality of air coolers 8 are switchably connected to a dry air discharge pipe 9; and the dry air discharge pipe 9 of the air dehumidifier 7 is connected to the air blowing nozzle. 2 by an air supply pipe 10, and has an air supply path structure that allows each of the plurality of air coolers 8 in the air dehumidifier 7 to be switched between cooling dehumidification operation and defrosting operation. A device for storing products in a clean and dry space.