JP2816225B2 - Air purification system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an air purification system capable of preventing the influence of dust generation during maintenance of a blower in a clean room air conditioning system in the field of semiconductors and the like.

[Conventional technology]

In a conventional clean room, a motor of a blower is present in a flow path of a return airflow of clean air as described in JP-A-58-127033 and JP-A-63-14257. Therefore, during maintenance such as inspection or failure of the blower, the maintenance worker works in the flow path of clean air,
In some cases, the cleanliness of the clean room was reduced by workers.

In a down-flow type clean room as shown in FIG. 9, the blower was present in the return airflow, and the problem of dust generation during maintenance was the same.

[Problems to be solved by the invention]

In the above prior art, no consideration is given to the contamination of the clean room during maintenance of the blower, and when a person enters the flow path during the maintenance, dust from the person and dust accumulated on the primary side of the filter are regenerated. There is a problem that the air is scattered and the cleanliness drops sharply to about the same level as in the general atmosphere. When the operation is restarted after maintenance is completed, dust adhering to the wall material etc. is re-scattered, and a super-clean system that suppresses 0.05μm particles to several or less per cubic foot is required as in a semiconductor (especially 16Mbit or more) manufacturing environment. In some cases, it may take several months to restore the cleanliness level immediately before the stoppage of the clean room operation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a blower motor having a higher maintenance frequency than a filter so that the blower motor can be maintained from the outside of a flow path of clean air, thereby preventing dust generated during maintenance from entering a clean room. It is to provide a cleaning system.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a cleaning room and a maintenance room separately provided above the cleaning room and separated by a ceiling, and air supply from the maintenance room to the cleaning room is provided. A duct, and a blower that is provided inside a portion of the air supply duct located in the maintenance room and blows air to the cleaning work chamber,
Air purifying means for purifying the air blown by the air blowing means and supplying the purified air to the cleaning work chamber; and an annular flow path for circulating the air passing through the clean working chamber from below the working chamber to the suction side of the air blowing means. The inside of the duct is isolated from the maintenance room, and communicates with the circulation channel on the suction side of the ventilation means,
The driving means for driving the blowing means is an air purification system provided in the maintenance room outside the air supply duct, wherein the air supply duct penetrates the ceiling, and the air purification means faces the cleaning work room on the side opposite to the blowing means with respect to the ceiling. The rotating shaft of the blowing means and the rotating shaft of the driving means are provided to face each other and are detachably connected by a joint.

Further, the present invention includes a cleaning work chamber, and a maintenance room separately provided on the ceiling above the cleaning work room and separated by a ceiling, and an air supply duct from the maintenance room to the cleaning work room; and an air supply duct. A ventilation means provided inside the portion located in the maintenance room for blowing air to the cleaning work chamber, an air purification means for purifying the air blown by the ventilation means and supplying the air to the cleaning work chamber, and passing through the cleaning work chamber A return passage for recirculating the air from below the working chamber to the suction side of the blowing means, the inside of the air supply duct is isolated from the maintenance room, and the air supply duct communicates with the return flow path on the suction side of the blowing means. The driving means for driving is an air purification system provided in a maintenance room outside the air supply duct, wherein the air supply duct penetrates the ceiling, and the air purification means is provided on the opposite side of the ceiling from the air blowing means and faces the cleaning work chamber. , Blast The rotating shaft of the step and the rotating shaft of the driving means are disposed to face each other and are detachably connected by a joint. The blowing means and the driving means are held in the maintenance room via the vibration isolating means and the air supply duct. Is characterized in that it is configured to communicate with the outlet of the blowing means via a flexible joint in the maintenance room.

[Action]

The cleaning work chamber includes an air flow path communicating with the cleaning work chamber, a purifying means provided in the air flow path, and a blowing means provided to blow air to the purifying means. Keep below a certain level. The air blowing means is provided inside a portion of the air supply duct located in the maintenance room, and the driving means for driving the air blowing means is provided in the maintenance room outside the air supply duct, and a rotation axis of the air blowing means and a rotation axis of the driving means are provided. Are arranged facing each other and detachably connected by a joint,
Maintenance from the outside of the air flow path of the driving means can be performed, so that maintenance work can be performed without an operator entering the air flow path, and dust generated during maintenance can be prevented from entering the air flow path. Further, the air supply duct penetrates through the ceiling, and the air purifying means is provided facing the ceiling on the opposite side of the air blowing means into the cleaning work chamber, and the air blowing means and the driving means are held in the maintenance room via the vibration isolating means. At the same time, the air supply duct is configured to communicate with the air outlet of the air blowing means via a flexible joint in the maintenance room, so that even if dust is generated due to wear or the like at the vibration isolating means or the joint, it can be blocked by the ceiling. It is possible to prevent contaminants from entering the cleaning work room.

〔Example〕

In the present embodiment, the present invention is applied to a clean room requiring very high cleanliness, for example, a super clean room used in a manufacturing process of a semiconductor having a very high degree of integration. In this type of clean room, the conditioned air supplied to the clean room is already highly purified, and the filter provided in the super clean room hardly clogs, and the filter is substantially maintenance-free. However, blowers are one or two
Maintenance inspections are required.

In the present embodiment, a clean area 30 is provided as a clean room in which a clean room 11 is provided as a clean working room, and a secure area 13 is provided as a separate secure room separated from the clean area 30 by a ceiling 2. A duct 10a as an air supply duct extending from the maintenance area 13 to the clean room 11, a blower 8 provided in the duct 10a as a blower for blowing into the clean room 11, and purifying the air blown by the blower 8 to clean the clean room 11 A HEPA filter 1 is provided as an air purification means for supplying air to the air supply unit, and a recirculation unit 12 is formed outside the clean room 11 in the clean area 30 and recirculates the exhaust air to the suction side of the blower 8. The clean room 11 discharges the air passing through the inside from the lower part to the return part 12, and the duct 10a isolates the inside from the maintenance area 13 and communicates with the return part 12 on the suction side of the blower 8 to drive the blower 8 The motor 3 as a driving means for driving
a is provided in the protection area 13 outside.

On the ceiling of the clean room 11, HEPA filter 1 and HE
A pressure chamber 10 is provided for communicating the PA filter 1 with the blower 8 via a duct 10a. Clean room in conservation area 13
A duct 24 for supplying air conditioned as outside air to 11;
Blower 8 that pressurizes air in duct 24 and supplies it to pressure chamber 10
And a mixing duct 9 that communicates with the suction port 8a of the blower 8 and mixes the air in the duct 24 with the return air from the return section 12. Reference numeral 11c denotes a side wall, and reference numeral 40 denotes a floor formed of a member through which airflow such as grating can flow.

In this embodiment, the return path is composed of the return section 12 and the mixing duct 9.
And a portion that communicates with the clean area 30.

The clean area 30 and the conservation area 13 are separated by the partition wall 2 and the blower 8
A duct 10a for supplying air from the pressure chamber 10 to the pressure chamber 10 and a lower end of the mixing duct 9 are provided through the partition wall 2.
In this embodiment, the air flow path extends from the mixing duct 9 to the pressure chamber.
It is the flow path part reaching to 10. A blower 8 as a blowing means is composed of a motor 3 as a driving means and an impeller 4, and the impeller 4 is stored in a fan case 8c provided in the air flow path, and the motor 3 has a rotating shaft 3a. Are provided through the fan case 8c, and the main body 3b is provided outside the fan case 8c which is a part of the air flow path. The motor 3 is provided in the maintenance area 13 so that an operator approaches for maintenance and can perform a predetermined operation.

The mixing duct 9 has an opening facing the cleaning area 30 and sucking the return air from the cleaning area 30. The connection between the opening and the air supply duct 24 to the clean room is used to shut off the air flow path. Dampers 5 and 6 are provided. In addition, a damper 7 for closing off the air flow path is provided in the air flow path from the fan case 8c to the pressure chamber 10.

A section surrounded by the dampers 5 and 6 of the mixing duct 9 communicates with a suction port 8 a of the blower 8, and the dampers 5 and 6 are located upstream of the suction port 8 a of the blower 8. Also,
The damper 7 is located on the downstream side with respect to the outlet 8 b of the blower 8.

The dampers 5, 6, and 7 are open in a normal operation state, and are set to flow a predetermined air flow at a predetermined opening degree. Further, when the blower 8 is maintained, the dampers 5, 6, and 7 are closed, and the upstream and downstream air flow paths of the blower 8 are closed to prevent the air in the maintenance area from flowing into the air flow path during the maintenance work. To prevent.

In this embodiment, during the clean room operation, the return airflow RA and the supply air flow path SA are pressurized by the blower 8 through the mixing duct 9, filtered by the HEPA filter 1, and supplied to the clean room 11 as clean air. .

The main components for air purification are the blower 8 and the HEPA filter 1. In a super-cleaned clean room, the return air in the recirculation zone 12 is extremely clean. Since the air supplied to the HEPA filter 1 is filtered by a filter (not shown), the air supplied to the HEPA filter 1 is completely free of dust. For this reason, the HEPA filter 1 does not need to be maintained without clogging, and the maintenance of the blower 8 having a rotating portion may be mainly considered.

The blower 8 includes a motor 3 and an impeller 4 connected to a rotating shaft 3a of the motor 3, and is rotatably supported by bearings (not shown). The impeller 4 is made with sufficient strength to continuously operate at the normal operation speed, and is provided in the airflow of the conditioned air, so that the bearings are kept at a low temperature, so that the frequency of failures such as breakage occurs. Is extremely small. On the other hand, when the motor 3 is operated continuously, a defect may occur in the insulating material, bearings, and the like due to the influence of heat, and regular maintenance and inspection are required once or twice a year.

In the present embodiment, the blower motor 3 is provided outside the airflow system of the clean room, and dust generated by an operator during maintenance of the motor is prevented from being mixed into the airflow in the clean room 1 to prevent a decrease in cleanliness. It is intended.

When replacing the blower motor 3, the supply air amount adjustment damper 6, the return air amount adjustment damper 5, and the total air amount adjustment damper 7 are fully closed to shut off the upstream and downstream air passages of the blower 8. Therefore, even if the blower 8 is removed, the clean area 30 and the maintenance area 13 can be isolated. for that reason,
The unpurified air in the protection area 13 can be prevented from entering the clean area 30, and the dust adhering to the primary side of the HEPA filter 1 does not enter the clean room 11 and the return system section 12 of the clean room even if re-scattered. So clean area 30
Does not lower the cleanliness of the product.

According to the present embodiment, compared to the case where the blower 8 is installed in the filter unit for cleaning as in the conventional example,
Since maintenance can be performed in the maintenance area 13 above the clean area without polluting the clean room 11 during inspection, workability is good, the inspection of the blower 8 can be easily performed, and preventive maintenance can be easily performed.

For this reason, the failure of the blower 8 can be prevented, and the occurrence of a serious failure that must stop the clean room can be prevented.

Further, according to the present embodiment, the motor 3 is provided in the protection area 13 and the air in the protection area 13
, The heat load of the motor 3 can be exhausted at the same time, so that the heat load of the clean room 11 can be reduced.
Energy saving effects can be obtained.

In addition, since the pressure around the pressurized chamber 10 and the HEPA filter 1 can be maintained at a lower pressure than that in the clean room 11, the HEPA filter 1 moves due to an earthquake or the like, and there is no possibility of air leak even if a crack occurs in the seal portion. A clean space can be obtained.

If the strength of the ceiling 2 is further increased, the blower 8 can be installed in the maintenance area 13, so that a vibration is hardly transmitted to the clean room 11, and a clean room with low vibration can be obtained. Further, since the blower 8 as a sound source can be installed with the ceiling 2 separated from the clean room 11, noise can be reduced. In order to further reduce noise, a sound absorbing material (not shown) is provided in the pressurized chamber 10. In super clean rooms such as semiconductors, in addition to improving cleanliness, noise reduction,
According to the embodiment, low vibration is required. However, according to the embodiment, it is possible to effectively cope with these three main requirements of improving cleanliness, reducing vibration, and reducing noise.

 A second embodiment of the present invention will be described with reference to FIG.

This embodiment is an example in which the present invention is applied to a clean room apparatus disclosed in Japanese Patent Application Laid-Open No. 58-127033.

In the present embodiment, the inside of the clean room 11 is divided into a work space 11a in which work equipment is installed and a passage space 11b through which workers pass, and the work spaces 11a are provided on both sides of the passage space.

A pressure chamber 10 is provided above the work space 11a.
A HEPA filter 1 for supplying clean air to the work space 11a and a HEPA filter 31 for supplying clean air to the passage space 11b are provided on the lower surface and the side surfaces of 0, respectively. HEPA
The clean air blown out of the filter 31 is supplied to the passage space 11b via the chamber 34 above the passage space 11b. The clean air supplied into the clean room 11 flows out to the recirculation section 12 through the recirculation port 11d below the side wall 11c and the air circulation section 42b on the floor surface 42, and through the opening of the mixing duct 9 on the ceiling surface 2. It returns to the suction port 8a of the blower 8.

Above the pressure chamber 10, a blower 8 isolated by a partition 2a is provided. In this embodiment, as in the first embodiment, the outlet 8b of the blower 8 communicates with the pressure chamber 10, the inlet 8b communicates with the mixing duct 9, and the outlet 8 and the mixing duct 9 communicate.
Are provided with dampers 5, 6, and 7, respectively. Note that the partition wall 2a may be formed by extending the ceiling of the building, or may also be used as the ceiling plate of the clean room apparatus.

In this embodiment, as in the first embodiment, the return air from the recirculation unit 12 and the supply air from the air supply duct 24 are mixed in a mixing duct 9 and pressurized by a blower 8 to form a HEPA filter 1.
And keep the inside of the clean room 11 clean.

In the present embodiment, a duct 15 communicating the mixing duct 9 and the periphery of the pressure chamber 10 is provided, and by maintaining the periphery of the pressure chamber 10 at a pressure lower than that in the clean room 11,
A stable cleanliness can be obtained by eliminating the potential of air leak.

According to the present embodiment, it is possible to realize a super clean room in which the floor height of the room where the clean room is installed is lower than that of the structure of the first embodiment, and the blower motor 3 can be easily maintained.

In the above embodiment, the weight of the motor 3 is the ceiling 2 or the ceiling.
Supported on 2a. When the motor 3 is lightweight, the weight of the motor 3 may be supported by the fan case 8c.

 A third embodiment of the present invention will be described with reference to FIG.

This embodiment is a clean room of the first embodiment,
Is changed to a ceiling suspension type. In this embodiment, a blower 8 is provided above a ceiling 2 of a building.
Suspended from 52 through a vibration-proof spring 18 as a vibration-proof means,
Furthermore, a joint made of a flexible material is used for a connection between the blower 8 and the mixing duct 9 and a connection between the blower 8 and the pressurizing chamber 10.
16 and 17 are used.

In this embodiment, it is possible to cut off the transmission of the vibration generated from the blower 8 to the clean room 11 side. Also,
By supporting the blower via the anti-vibration spring 18, the transmission of vibration to the upper floor can be reduced. The joints 16 and 17 can cut off transmission of vibration by using a flexible joint such as a chamber or a joint made of a flexible material such as a soft bellows.

 A fourth embodiment of the present invention will be described with reference to FIG.

This embodiment is an example in which the blower 8 is housed in a blower case 19. Electrical components 44 such as a thermal relay and a contactor are housed in the blower case 19, and are configured so that maintenance can be performed for each unit in a cassette manner. In this embodiment, as in the third embodiment, the blower 8 is provided with a vibration isolating spring 18.
The air inlet 8a and the air outlet 8b of the blower 8 communicate with the mixing duct 9 and the pressure chamber 10 via flexible joints 17 and 16, respectively.

In this embodiment, the dampers 5, 6, and 7 are electric dampers, and are linked with the output of a sensor (a limit switch, a reed switch, etc.) for detecting that the blower case 19 is at a fixed position. The dampers 5, 6, 7 may be automatically closed by removing from the home position. The openings 20 on the top and side surfaces of the blower case 19 are openings for inspection of the motor 3 and for circulation of cooling air.

In each of the above embodiments, the supply air amount adjusting damper 6, the return air adjusting damper 5, and the total air amount adjusting damper 7 are linked with the operation of the blower 8 as an electric damper, and the damper is automatically closed when the blower is stopped. Further, it is possible to prevent dust accumulated on the upstream side of the HEPA filter 1 from flowing out to the clean area 30 through the return portion 12 when the clean room is stopped or when the fan alone stops abnormally.

 A fifth embodiment of the present invention will be described with reference to FIG.

In this embodiment, at least two pressure chambers 10 communicate with each other in a clean room, and when one of the blowers is abnormally stopped, the duct system dampers 5, 6,
7 shows an example in which 7 is automatically closed. As means for automatically closing the damper, electric dampers are used for the dampers 5, 6, and 7, and abnormal stop detecting means 54 is provided for each motor.
Alternatively, a mechanical damper that is opened and closed by air pressure and dynamic pressure may be used. According to the present embodiment, it is possible to prevent a decrease in cleanliness in a clean room clean area when one unit abnormally stops,
In addition, it is also possible to prevent a decrease in cleanliness during maintenance.

The abnormal stop detecting means 54 includes, as an example, a rotation detecting means such as an encoder connected to the rotating shaft 3a of the motor,
It comprises voltage detecting means such as a photocoupler for detecting the voltage supplied to the motor 3 and mismatch detecting means such as a logic circuit for detecting a mismatch between the output of the rotation detecting means and the output of the voltage detecting means. .

 A sixth embodiment of the present invention will be described with reference to FIG.

In this embodiment, the ceiling 2 is constituted by two ceiling plates 2b and 2c, and an air supply duct 24 is provided between them. In this embodiment, a duct 10a for communicating the pressure chamber 10 with the outlet 8b of the blower 8 and a duct 59c for communicating the return air from the recirculation unit 12 with the mixing duct 59 are ceiling plates 2b and 2c.
A duct 59d that allows the air in the air supply duct 24 to communicate with the mixing duct 59 is provided through the ceiling plate 2b. The blower 8 is fixed together with the motor 3 to a box-shaped mounting frame 60 having an open top. A mixing duct 59 is connected to the suction port 8a of the blower 8, and the mixing duct 59 has a portion 59a communicating with a duct 59c communicating with the through-flow portion and a portion 59b communicating with a duct 59d communicating with the air supply duct 24. ,
Each of the mounting frames 60 has a connection opening on the lower surface thereof so as to be connectable to the ducts 59c and 59, respectively. The outlet 8b of the blower 8 has a mounting frame 6 so that it can be connected to a duct 10a communicating with the pressure chamber 10.
0 has a connection opening on the lower surface. Electrical components 44 such as contactors and thermal relays are also mounted on the mounting frame 60. In this embodiment, the connection between the blower 8 and each duct can be made only by placing the mounting frame 60 on the upper surface of the ceiling 2b so that the respective connection openings are aligned. When inspecting the blower, lift the mounting frame 60 together to release the connection with each duct and move to the inspection location. In order to facilitate the movement to the inspection place, a rail 70 is provided on the ceiling of the work area 13, and a hoist 72 movable along the rail 70 is provided.
May be lifted and moved. Further, in this embodiment, the dampers 5, 6, 7 are used as electric dampers,
These dampers are configured to close in conjunction with the lifting of 60. In the present embodiment, by providing a spare mounting frame, the spare mounting frame can be immediately mounted at the position of the mounting frame removed for maintenance, and the time during which the clean room is stopped for maintenance. Can be shortened.

In the above embodiment, both ends of the shaft of the impeller 4 are rotatably supported by bearings 22 as shown in FIG.
A joint 21 with the shaft 3a of the motor may be provided on the side facing the shaft, and the motor 3 may be configured to be separable from the impeller 4 at this portion.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to this invention, the maintenance of a motor for blowers can be facilitated, and the air purification system which can prevent dust generated at the time of maintenance from entering a clean room can be obtained.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a configuration of an air cleaning system according to a first embodiment of the present invention, FIG. 2 is a front sectional view showing a configuration of an air cleaning system according to a second embodiment of the present invention, and FIG. FIG. 4 is a front sectional view showing a configuration of a main part of an air cleaning system according to a third embodiment of the present invention.
FIG. 5 is a front sectional view showing the structure of the main part of the air cleaning system in the embodiment, FIG. 5 is a front sectional view showing the structure of the main part of the air cleaning system in the fifth embodiment of the present invention, and FIG. FIG. 7 is a front sectional view showing a configuration of a main part of an air cleaning system in a sixth embodiment, and FIG. 7 is a front view of a main part showing a configuration for facilitating attachment and detachment of a motor in each of the above embodiments of the present invention. 1 ... main filter, 2 ... ceiling, 3 ... motor, 4
... impeller, 5 ... damper for adjusting the return air amount, 6 ...
… Supply air amount adjustment damper, 7… Total air amount adjustment damper, 8… Blower, 9 …… Mixing duct, 10 ……
Pressure chamber, 11… Clean room, 12… Reflux section, 13 ……
Working part, 14 ... ventilator, 15 ... duct, 16 ... fitting, 17
…… Fitting, 18 …… Vibration isolation spring, 19 …… Blower case, 20…
... vents, 21 ... joints, 22 ... bearings.

Continuation of the front page (72) Inventor Keiichi Honma 4-3-3 Kanda Surugadai, Chiyoda-ku, Tokyo Within Hitachi Techno Engineering Co., Ltd. (56) References JP-A-1-179840 (JP, A) JP-A-2-29581 ( JP, A) JP-A-58-127033 (JP, A) JP-A-61-178136 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F24F 7/06

Claims (2)

(57) [Claims] An air supply duct extending from the maintenance room to the cleaning operation room, the air supply duct including a cleaning room, and a maintenance room separately provided above the cleaning operation room and separated by a ceiling. Air blowing means provided inside a portion of the air duct located in the maintenance room and blowing air to the cleaning work chamber; air purifying means for purifying air blown by the blowing means and supplying the air to the cleaning work chamber; An air flow passage for circulating the air passing through the clean working chamber from below the working chamber to the suction side of the blowing means, wherein the inside of the air supply duct is isolated from the maintenance chamber and suction of the air blowing means is provided. The driving means for communicating with the annular flow path on the side and driving the blowing means is an air cleaning system provided in the maintenance room outside the air supply duct, wherein the air supply duct penetrates the ceiling and the air The baffling means is provided facing the cleaning work chamber on the side opposite to the blowing means with respect to the ceiling, and the rotation axis of the blowing means and the rotation axis of the driving means are disposed opposite to each other and detachable with a joint. An air purification system characterized by being connected to the air purifier. 2. A cleaning room, and a maintenance room separately provided above the cleaning room and separated by a ceiling, and provided with an air supply duct extending from the maintenance room to the cleaning room; Air blowing means provided inside a portion of the air duct located in the maintenance room and blowing air to the cleaning work chamber; air purifying means for purifying air blown by the blowing means and supplying the air to the cleaning work chamber; An air flow passage for circulating the air passing through the clean working chamber from below the working chamber to the suction side of the blowing means, wherein the inside of the air supply duct is isolated from the maintenance chamber and suction of the air blowing means is provided. The driving means for communicating with the annular flow path on the side and driving the blowing means is an air cleaning system provided in the maintenance room outside the air supply duct, wherein the air supply duct penetrates the ceiling and the air The baffling means is provided facing the cleaning work chamber on the side opposite to the blowing means with respect to the ceiling, and the rotation axis of the blowing means and the rotation axis of the driving means are disposed opposite to each other and detachable with a joint. Connected to
The blowing means and the driving means are held in the security room via vibration isolating means, and the air supply duct is configured to communicate with the outlet of the blowing means via a flexible joint in the security room. An air purification system characterized by the following.