Low-humidity working apparatus

TECHNICAL FIELD

The present invention relates to an apparatus which implements a working space with low humidity, a dew point in which is −20° C. or less, and with high workability.

BACKGROUND ART

A working space with low humidity is needed for production of a lithium-ion battery, for example. In this low-humidity working space, a caulking operation of a member containing lithium or the like is conducted. Lithium ions are converted into lithium metal by overcharge, which metal is converted into Li

3

N through chemical reaction in the presence of water vapor, so that the working space must be kept at low humidity.

In the case where the worker goes into the low-humidity working space, his (her) eyes get dry, the mucous membrane of his (her) nose and his (her) lips get cracked, and he/she easily gets infected with a common cold virus. Further, due to sweat of the worker, it is difficult to retain low-humidity condition.

A prior art which solves these problems is shown in FIG.

15

. This prior art is called a glove box, wherein a hermetic housing

2

provided with two flexible gloves

1

is equipped with a transparent glass plate

3

for viewing the interior working space and a pass box

4

placed alongside the housing, so as to be capable of opening/closing and hermetic. The glass plate

3

or the pass box

4

is opened, an item to work with is placed in the housing

2

, and thereafter the glass plate

3

or the pass box

4

is hermetically closed. After the air in the housing

2

is forcefully exhausted by a vacuum pump mounted additionally, a dry inert gas such as argon is encapsulated from a pressuring reservoir

5

into the housing up to the normal pressure, which is the atmospheric pressure. The worker can insert his(her) hands and forearms in the gloves

1

, and work with the item placed in the housing

2

under low humidity condition.

New problems in the prior art shown in

FIG. 15

will be described. An inert gas such as argon is encapsulated into the working space in the housing

2

, and the gloves

1

are provided in order to keep the encapsulated gas from dissipated into the atmosphere and outside air from entering the working space. Therefore, the worker needs to work via the gloves

1

, with the result that the workability is lowered.

Further, every time an item is placed in and taken out of the working space of the housing

2

, it is needed to forcefully exhaust the air in the working space and replace the inert gas such as argon, with the result that the workability is lowered.

An object of the invention is to provide a low-humidity working apparatus which has been improved so as to allow an operation in a working space with low humidity at an excellent workability.

DISCLOSURE OF THE INVENTION

The invention provides a low-humidity working apparatus comprising:

(a) a housing

8

which forms a working chamber

9

, the housing having a surrounding wall provided with an operating hole

30

through which a worker is allowed to insert both of his (her) upper limbs into the housing

8

, at least a portion of the housing in a vicinity above or alongside the operating hole

30

transmitting light;

(b) a dehumidifying apparatus

18

for lowering a dew point of air in the working chamber

9

to −20° C. or less, including dehumidifying means

42

for dehumidifying air supplied from the operating chamber, and circulating means for circulating the dehumidified air by returning to the working chamber

9

; and

(c) air supply means for supplying outside air to the dehumidifying means

42

to keep the working chamber

9

at positive pressure.

According to the invention, the housing

8

forms the working chamber

9

serving as a low-humidity working space, the dehumidifying means dehumidifies the air coming from the working chamber

9

, and the air thus dehumidified is circulated by returning to the working space

9

. Thus, the interior of the working chamber

9

is kept to be a low-humidity space at high efficiency. The dew point of the air in the working chamber

9

is lowered to −20° C. or less, and determined in the range of −20° C. to −70° C., for example. Under low-humidity condition with such a low dew point, in the case where the worker goes inside, he/she comes upon a situation as mentioned above such that his (her) eyes get dry, the mucous membrane of his (her) nose and his (her) lips get cracked, and he/she easily gets infected with a common cold virus. The worker can insert both of his(her) upper limbs into the working chamber

9

through the operating hole

30

formed on the surrounding wall, thereby conducting an operation in the working chamber

9

. Therefore, the worker's eyes would not come in contact with the air in the low-humidity working chamber

9

, the mucous membrane of his(her) nose and his (her) lips would not get dry or cracked, and he/she would not get infected with a common cold virus.

Further, in order to keep the working chamber

9

at positive pressure, air is supplied from outside to the dehumidifying means

42

. That is to say, the working chamber

9

is kept at slightly higher pressure, for example, at a pressure of 0.5-10 mmH

2

O higher than the atmospheric pressure. Therefore, it is possible to minimize the amount of air entering the working chamber

9

through the operating hole

30

. Thus, the humidity in the working chamber

9

is kept low at all times.

The operating hole

30

is formed so as to be laterally elongated, for example, and is capable of letting both the upper limbs in. Therefore, the gloves mentioned with reference to the prior art described above are not used in the invention, and hence the workability is excellent. Both the upper limbs may include only the worker's hands, or may include his(her) hands and forearms, or may include his (her) hands, forearms, and upper arms. Since both the upper limbs can be inserted at a time into the working chamber

9

through the inserting hole

30

, the workability is extremely good, and moreover, it is possible to bring an item, jig or the like into the working chamber

9

or take it out of the working chamber

9

through the operating hole

30

, which item, jig or the like should be subjected to various operations such as a caulking operation in the working chamber

9

. Also in consideration of this, the workability is excellent. Furthermore, as mentioned above, the working chamber

9

is kept at the positive pressure by circulating dry air which is circulated, so that it is possible to minimize the amount of the outside air entering the working chamber, at the time of inserting the upper limbs and an item, jig or the like and taking them out via the operating hole

30

.

In order to allow the worker to view working status in the working chamber

9

from outside, at least a portion of the housing in a vicinity above or alongside the operating hole

30

is made to transmit light.

Further, the low-humidity working apparatus of the invention is characterized in that:

the dehumidifying apparatus

18

and the air supply means include cooling means

48

,

58

, respectively, and

the air supplied from the working chamber

9

and the air supplied from outside are sent to the dehumidifying means

42

via the cooling means

48

,

58

, respectively.

According to the invention, the circulated air and the air supplied from outside are cooled by the cooling means

48

,

58

, and thereafter supplied to the dehumidifying means

42

. Thus, relative humidity at the entrance of the dehumidifying means

42

is higher, and dehumidifying efficiency is enhanced. The cooling means

48

,

58

are provided separately for the circulated air and the air supplied from outside, because these airs have different dew points.

Still further, the low-humidity working apparatus of the invention is characterized in that the cooling means is a compression refrigerating machine

41

which has two evaporators

48

,

58

arranged in parallel.

The cooling means according to the invention is preferably, but not limited to, the compression refrigerating machine

41

. In specific, when the working chamber

9

is small in size and troubled by vibration and noise, a Peltier freezer is used. The compression refrigerating machine

41

is relatively small in size and is capable of cooling an object (air) to be cooled at high efficiency. Further, although it is also possible to use two compression refrigerating machines for cooling the circulated air and for cooling the air supplied from outside, it is preferable to arrange two evaporators in parallel and share other components in one unit, which takes up a smaller space. In this case, one evaporator

48

cools the circulated air, and the other evaporator

58

cools the air supplied from outside.

Still further, the low-humidity working apparatus of the invention is characterized in that the operating hole

30

is provided with sealing means.

According to the invention, the working hole

30

is sealed by the sealing means. Although it is preferable that the working hole

30

is not sealed in view of workability, such a structure has a drawback of increasing the amount of outside supply air. In specific, when a dew point is −40° C. or less, it is necessary to reduce the amount of outside air supply, so that it is necessary to seal.

Still further, the low-humidity working apparatus of the invention is characterized in that the sealing means is composed of longitudinally elongated flexible sealing members

37

which are arranged laterally adjacent to each other and drooped from a top of the operating hole

30

, bottom ends of which members are slightly above a bottom end of the operating hole

30

.

According to the invention, the sealing means is formed by laterally arranging a plurality of strip sealing members

37

which are longitudinally elongated thin plates, adjacent to each other, to be suspended and drooped from the top of the operating hole

30

. Therefore, the worker can easily insert his (her) upper limbs through the operating hole

30

and easily take his(her) upper limbs out of the working chamber

9

, and moreover, the outer regions of the upper limbs are closed by the sealing members

37

during operation, whereby it is possible to avoid waste such that the dry air with low humidity in the working chamber leaks outside in large amount.

The sealing member

37

may be elastic as well as flexible, and may be formed of natural rubber, synthetic rubber, or a synthetic resin material such as vinyl chloride, for example.

The bottom end of the sealing member

37

is slightly above the bottom end of the operating hole

30

with a space of approximately 0.5-5 mm. Thus, in the status where the sealing member

37

is vertically drooped due to its own weight, it is possible to keep the low-humidity air in the working chamber

9

from leaking outside in large amount, and it is possible to minimize the amount of the air entering from outside. In the case where the bottom end of the sealing member

37

were below the bottom end of the operating hole

30

, the bottom end of the sealing member

37

in the vicinity of the bottom end of the operating hole

30

would be on the side of the working chamber

9

or outside the housing

8

. Therefore, if, for example, the bottom end of one of two sealing members

37

adjacent to each other were inside the working chamber

9

in the vicinity of the bottom end of the operating hole

30

, and the bottom end of the other were outside the housing

8

, a gap would be produced between these sealing members

37

, with the result that the air in the working chamber

9

easily leaks outside and the outside air easily enters the working chamber. The invention solves this problem.

Still further, the low-humidity working apparatus of the invention is characterized in that:

a laterally elongated window hole

31

with a length more than a lateral length of the operating hole

30

is formed around an upper portion of the surrounding wall of the housing

8

; and

a window plate

32

made of light-transmitting material is hermetically secured to the window hole

31

.

According to the invention, the window hole

31

is formed on the housing

8

. This window hole

31

is formed in a vicinity above or alongside the operating hole

30

of the surrounding wall, having a length L

2

more than a lateral length L

1

of the operating hole

30

and a laterally elongated shape. A vertical height H

3

of the window hole

31

may be set to a value as large as possible in accordance with the dimension and shape of the working chamber

9

.

To this window hole

31

, the window plate

32

composed of a light-transmitting material, for example, a synthetic resin material such as an acrylic resin, or glass, is hermetically secured. Thus, the low-humidity air in the working chamber

9

would not leak outside, the outside air would not enter the working chamber

9

, and in addition, the worker can view operation status from outside via the window plate

32

as he/she inserts his(her) upper limbs into the working chamber

9

through the operating hole

30

. As a result, the workability is enhanced.

Although the housing

8

, whose material is not limited in specific, may be composed of transparent plastics, it is to be hermetically composed of metal or plastic which are used in general. These materials are lightproof, and such a housing is preferable that the window hole

31

is placed above the operating hole

30

.

Still further, the low-humidity working apparatus of the invention is characterized in that:

the housing

8

is mounted on a mounting base

35

,

a vertical height H

1

of the operating hole

30

is approximately 0.15-0.40 m, and a lateral length L

1

of the operating hole is approximately 0.3-2.0 m,

a height H

2

from a floor to a bottom end of the operating hole

30

is approximately 0.5-1.4 m; and

a lateral length L

2

of the window hole

31

of the housing

8

is nearly equal to the lateral length L

1

of the operating hole

30

.

According to the invention, the housing

8

is mounted on the mounting base provided with wheels

34

, or according to another idea of the invention, the wheels may be omitted.

The vertical height H

1

and lateral length L

1

of the operating hole

30

are set to the dimensions mentioned above, whereby the worker can insert his(her) upper limbs into the working chamber through the operating hole

30

while he/she keeps an easy-to-work position in a status of sitting on a chair or standing on the floor.

Furthermore, the height H

2

from the floor to the bottom end of the operating hole

30

is set to the dimension mentioned above, whereby the worker can insert his(her) upper limbs into the working chamber through the operating hole

30

in a natural status while he/she is sitting on a chair or standing on the floor.

The lateral length L

1

of the operating hole is set, as mentioned above, to a value which allows the worker to insert both of his (her) upper limbs at a time into the working chamber

9

through the operating hole

30

and smoothly conduct an operation in the working chamber

9

with both of his(her) hands.

Further, the lateral length L

1

of the operating hole

30

and the lateral length L

2

of the window hole

31

of the housing

8

are nearly equal to each other, and therefore the worker can insert both of his (her) upper limbs into the working chamber

9

through this operating hole

30

and view both of his (her) hands and so on to successfully conduct an operation while viewing an operation status, with the result that the workability is extremely good.

Still further, the low-humidity working apparatus of the invention is characterized in that the housing is provided with a leading hole

11

for leading the dehumidified air supplied from the dehumidifying apparatus

18

to the working chamber

9

, the leading hole being provided with a dustproof filter

29

.

According to the invention, the air dehumidified by the dehumidifying apparatus

18

is led from the leading hole

11

into the working chamber

9

via the dustproof filter

29

. A pressure loss of this dustproof filter

29

enables the dehumidified air with low humidity to be led from the leading hole

11

at a substantially uniform distribution of flow rate. Therefore, it is avoided that the air supplied from the leading hole

11

is flowed into the working chamber

9

in an unbalanced manner. Thus, the dustproof filter

29

not only performs its original function of removing tiny dust, but also causes a pressure loss to ensure a uniform flow rate of the dry air with low humidity supplied from the leading hole

11

.

Still further, the low-humidity working apparatus of the invention is characterized in that:

the leading hole

11

is formed on a top of the working chamber

9

; and

an exhausting hole

14

formed at a bottom of the working chamber

9

takes out the air in the working chamber

9

and leads the air to the dehumidifying apparatus

18

.

According to the invention, the leading hole

11

for leading the dehumidified air into the working chamber

9

is formed on the top of the working chamber

9

, and at the bottom of the working chamber

9

is formed the exhausting hole

14

, by which the air in the working chamber

9

is taken out and led to the dehumidifying apparatus

18

. Therefore, the dry air flows within the working chamber

9

from top to bottom without turbulence. Thus, the air would not stagnate or flow in an unbalanced manner within the working chamber

9

, so that it is possible to keep the entire space inside the working chamber

9

in low-humidity condition. As a result, it is possible to form a high-accuracy and low-humidity working space, and conduct an operation inside in a reliable manner.

Still further, the low-humidity working apparatus of the invention is characterized in that the air supply means includes:

pressure detecting means

83

for detecting air pressure in the working chamber

9

;

a fan

52

for sucking in the outside air; and

means in response to an output of the pressure detecting means, for controlling a flow rate of the air taken in from outside so that air pressure in the working chamber

9

becomes to a predetermined value higher than the atmospheric pressure.

According to the invention, in order to keep the interior of the working chamber

9

at the positive pressure slightly higher than the normal pressure of the atmospheric pressure and thereby avoid sucking in the outside air through the operating hole

30

in a reliable manner, the air pressure in the working chamber

9

is detected by the pressure detecting means, and the flow rate of the air supplied from the air supply means is controlled so that the air pressure in the working chamber

9

becomes a predetermined value. As an example for controlling the flow rate of the air, the rotation speed of the fan for sucking the outside air is changed or a flow control valve

86

is interposed at some midpoint in a flow path of the air from outside, whereby the rotation speed of the fan is increased or an opening of the flow control valve

86

is increased when the air pressure in the working chamber

9

falls short of the predetermined value, and the opposite operation is conducted when the air pressure exceeds the predetermined value. Thus, it is possible to keep the air pressure in the working chamber

9

at the predetermined value at all times by conducting negative feedback control.

Still further, the low-humidity working apparatus of the invention is characterized in that the dehumidifying means

42

includes:

(a) a dehumidifying rotor

61

having a substantially cylindrical shape as a whole,

the dehumidifying rotor

61

being composed of a substrate carrying a dehumidifying agent, and having a lot of gas through holes elongated in the axial direction;

(b) means

63

for driving the dehumidifying rotor

61

to rotate about an axial line thereof;

(c) air guiding means

65

for supplying the circulated air coming from the working chamber

9

and the air coming from the air supply means, to a dehumidifying processing section

54

from one side to the other side in an axial direction of the dehumidifying rotor

61

,

supplying air for regeneration use to a regenerating section

67

from the other side to the one side in the axial direction of the dehumidifying rotor

61

and exhausting the air from the regenerating section

67

to the outside,

supplying part of air to be returned from the dehumidifying rotor

61

to the working chamber

9

, to a purging section

68

from the other side to the one side in the axial direction of the dehumidifying rotor

61

, and

leading the air supplied from the purging section

68

, to the regenerating section

67

as part of the air for regeneration use,

the dehumidifying processing section

54

, regenerating sections

67

and purging sections

68

being formed by partitioning the dehumidifying rotor

61

into the sections in a peripheral direction of the dehumidifying rotor

61

in this order along a a rotational direction at both of axial ends thereof; and

(d) a heater

72

for heating the air for regeneration use to be supplied to the regenerating section

67

.

According to the invention, the dehumidifying means

42

is provided with the dehumidifying rotor

61

whose entire shape is substantially cylindrical, wherein the air guiding means supplies the air to be dehumidified coming from the evaporators

48

,

58

from one side to the other side of the dehumidifying rotor

61

in the axial direction, to the dehumidifying processing section

54

composing part of the dehumidifying rotor

61

in the peripheral direction. The dehumidifying rotor

61

shifts from the dehumidifying processing section

54

to the regenerating section

67

, where the air for regeneration use is heated by the heater

72

, supplies the heated air from the other side to the one side of the dehumidifying rotor

61

in the axial direction, that is, in the opposite direction to the direction of air flow at the dehumidifying processing section

61

, and thereby releases water vapor or water drop caught by the dehumidifying agent of the dehumidifying rotor

61

, with the air for regeneration use. The air for regeneration use which passed through the regenerating section

67

and having high humidity is dissipated outside.

The dehumidifying rotor

61

rotates to shift from the regenerating section

67

to the dehumidifying processing section

54

, between which sections the purging section

68

is formed in the peripheral direction. Part of the air to be returned from the dehumidifying processing section

54

of the dehumidifying rotor

61

to the working chamber

9

is taken out and supplied to this purging section

68

, and in this purging section

68

, the air is supplied from the other side to the one side of the dehumidifying rotor

61

in the direction of the axial line. In other words, the air for purging is supplied in the opposite direction to the direction of air flow at the dehumidifying processing section

54

. Thus, the air for regeneration use remaining in the air having passed through the regenerating section

67

of the dehumidifying rotor

61

is taken out of the dehumidifying rotor

61

together with the air dried at the purging section, and since this air exhibits relatively low humidity, it is again led to the regenerating section

67

as air for regeneration use and used for regeneration of the dehumidifying rotor

61

.

BRIEF DESCRIPTION OF THE DRAWINGS

Other and further objects, features, and advantages of the invention will be more explicit from the following detailed description taken with reference to the drawings wherein:

FIG. 1

is a simplified system view of a low-humidity working apparatus

7

of an embodiment of the invention;

FIG. 2

is a view in perspective of part of the low-humidity working apparatus

7

shown by

FIG. 1

;

FIG. 3

is a perspective view of the overall low-humidity working apparatus

7

;

FIG. 4

is a side view of the low-humidity working apparatus

7

;

FIG. 5

is a simplified section view of a low-humidity working apparatus

7

of another embodiment of the invention;

FIG. 6

is an enlarged front view of an operating hole

30

;

FIG. 7

is a section view taken on section line VII—VII of

FIG. 6

;

FIG. 8

is a simplified view of a configuration of dehumidifying means

42

;

FIG. 9

is a front view of part of a dehumidifying rotor

61

;

FIG. 10

is a simplified front view of the dehumidifying rotor

61

;

FIG. 11

is a block diagram showing an electrical configuration in an embodiment of the invention;

FIG. 12

is a block diagram showing an overall configuration of the dehumidifying means

42

in another embodiment of the invention;

FIG. 13

is a time chart in the another embodiment of the invention;

FIG. 14

is a simplified perspective view of a low-humidity working apparatus

7

a in still another embodiment of the invention; and

FIG. 15

is a perspective view of a prior art.

BEST MODE FOR CARRYING OUT THE INVENTION

Now referring to the drawings, preferred embodiments of the invention are described below.

FIG. 1

is a simplified system view of a low-humidity working apparatus

7

of an embodiment of the invention. Into a working chamber

9

formed in a housing

8

, low-humidity air is led as shown by an arrow

12

from a leading hole

11

of a ceiling

10

which is the top of the working chamber

9

. The air flows from top to bottom in the working chamber

9

, and the air is exhausted as shown by an arrow

15

from an exhausting hole

14

at a bottom

13

of the working chamber

9

, led to a dehumidifying apparatus

18

through a path

17

, and subjected to dehumidification. Thus, in the working chamber

9

, a dew point of air is kept at −20° C. or less. This dew point of the air in the working chamber

9

is kept between −20° C. and −70° C., preferably between −40° C. and −70° C.

FIG. 2

is a view in perspective of part of the low-humidity working apparatus

7

shown by

FIG. 1

,

FIG. 3

is a front view of the overall low-humidity working apparatus

7

, and

FIG. 4

is a side view of the low-humidity working apparatus

7

. Referring to these drawings, the housing

8

is basically made of metal such as steel or stainless steel, and in another embodiment, the overall housing

8

may be made of a light-transmitting synthetic resin material such as acrylic resin or may be made of a lightproof synthetic resin material.

FIG. 5

is a simplified section view of a low-humidity working apparatus

7

of another embodiment of the invention. Components of this embodiment shown in

FIG. 5

which corresponds to those of the embodiment shown in

FIGS. 1

to

4

will be denoted by the same reference numerals. The low-humidity working apparatus

7

shown in

FIG. 5

is relatively small in size, in which the dehumidifying apparatus

18

is placed at the bottom of the working chamber

9

. Comparing the embodiment shown in

FIGS. 1-4

with the embodiment shown in

FIG. 5

, the configurations regarding the working chamber

9

and the dehumidifying apparatus

18

are similar to each other. The working chamber

9

is formed by the ceiling

10

, the bottom

13

, both side walls

19

,

20

, a front plate

21

, and a rear plate

22

. In the configuration shown in

FIG. 2

, the side wall

19

is relatively large in size, to which a lid

23

can be detachably attached in a hermetic manner, and therefore the lid

23

can be opened to put a relatively huge working machine or the like into the working chamber

9

and conduct an operation under a low-humidity condition. Although the front plate

21

is formed by a vertical portion

21

a

which is vertically elongated and a leaning portion

21

b

in which an upper portion is more leaning to the rear side, this front plate

21

may be formed vertically in another embodiment of the invention.

At the bottom

13

of the working chamber

9

, a bottom header

24

is formed facing to an exhausting hole

14

, and low-humidity air is led to the dehumidifying apparatus

18

through a tube path

25

.

The dry air whose humidity is lowered by the dehumidifying apparatus

18

goes up via a path

27

formed between the rear plate

22

and an outer wall

26

, thereby led to a header

28

formed above the ceiling

10

. The low-humidity air in the header

28

, from which dust is removed by a dustproof filter

29

mounted facing to a leading hole

11

, can be led from the leading hole

11

into the working chamber

9

at a uniform distribution of flow rate due to a pressure loss of the filter

29

.

The ceiling

10

, the bottom

13

, both the side walls

19

,

20

, the front plate

21

and the rear plate

22

of the housing

8

forming the working chamber

9

compose a surrounding wall. On the vertical portion

21

a

of the front plate

21

is formed an operating hole

30

which is laterally elongated and substantially rectangular. Into this operating hole

30

, the operator can insert both of his (her) upper limbs at a time. The upper limbs may include only the operator's hands, may include only his (her) hands and forearms, or may include his (her) hands, forearms, and upper arms.

In the vicinity of and above the operating hole

30

, a laterally elongated window hole

31

is formed on the leaning portion

21

b

of the front plate

21

. This window hole

31

is hermetically closed by a light-transmitting window plate

32

. The window plate

32

may be made of a synthetic resin such as an acrylic resin, or may be a glass plate or the like.

In

FIG. 3

showing the operating hole

30

, a vertical height H

1

of the operating hole

30

is approximately 0.15-0.40 m, which facilitates insertion and release of the worker's upper limbs. A lateral length L

1

of the operating hole

30

is approximately 0.3-2.0 m, which allows the worker to insert both of his(her) upper limbs into and release them from the operating hole

30

, and move from side to side with his (her) upper limbs let in the operating hole

30

.

A bottom end

33

of the operating hole

30

is spaced from the floor by a height H

2

, the height H

2

being approximately 0.5-1.4 m. Therefore, the worker can insert his(her) upper limbs into the operating hole

30

while he/she is sitting on a chair, or the worker can easily insert his (her) upper limbs into the operating hole

30

while he/she is standing on the floor. As a result, the workability is enhanced. The housing

8

forming the working chamber

9

is mounted on a mounting base

35

provided with a plurality of wheels

34

, or the wheels

34

may be omitted.

A lateral length L

2

of the window hole

31

is set nearly equal in value to the lateral length L

1

of the operating hole

30

. The operating hole

30

and the window hole

31

are arranged side by side so as to be horizontal and in parallel. Although the window hole

31

is placed in the vicinity of and above the operating hole

30

in the respective embodiments described above, the window hole

31

in another embodiment of the invention may be placed on one side or both sides of the operating hole

30

, close to the operating hole

30

, and made so as to be closed by the window plate

32

as mentioned above.

FIG. 6

is an enlarged front view of the operating hole

30

, and

FIG. 7

is a section view taken on section line VII—VII of FIG.

6

. To close the operating hole

30

, sealing means

36

is provided. This sealing means

36

includes a lot of sealing members

37

which are a lot of thin plates of strips. The sealing members

37

are secured to the top, for example, to a top end

38

of the operating hole

30

, from which they are suspended and drooped down in the vertical direction. These sealing members

37

are arranged laterally adjacent to each other without overlapping each other in the thickness direction and with hardly producing a gap in the lateral direction. A bottom end

37

a

of the sealing member is slightly above the bottom end

33

of the operating hole

30

by a gap Δd. Δd may be, for example, in the range of 0.5-5 mm, whereby it is possible to minimize the amount of low-humidity air in the working chamber

9

which leaks outside, and ensure to close substantially the entire operating hole

30

by the sealing members

37

.

This sealing member

37

has a width W

1

which is 2-20 mm, preferably approximately 10 mm, and a thickness D

1

is 1-3 mm, preferably 1-2 mm. The sealing member

37

is made of natural rubber or synthetic rubber such as silicon rubber, or may be made of a synthetic resin material. Such materials have flexibility, and in addition, have elasticity. Since the sealing member

37

has elasticity, it is possible to ensure to close the operating hole

30

by elasticity of the sealing member

37

and prevent the operating hole

30

from opening due to the positive pressure of the working chamber

9

. Thus, it is avoided that the low-humidity air in the working chamber

9

leaks outside, whereby wastes are cut. In another embodiment of the invention, the sealing member

37

may have only flexibility without elasticity.

The sealing member

37

may not be mounted on the operating hole

30

in the case where a dew point temperature is relatively high −30° C. or more. The sealing means

36

may have another structure instead of a structure with the sealing member

37

.

Referring to

FIG. 1

again, the dehumidifying apparatus

18

basically includes a compression refrigerating machine

41

, dehumidifying means

42

and air take-in means

43

. The compression refrigerating machine

41

includes a compressor

44

for compressing a coolant, a condenser

45

to which the coolant from the compressor

44

is supplied, an expansion valve

47

to which the liquid coolant from the condenser

45

is supplied via a tube path

46

, an evaporator

48

, and a tube path

49

into which the coolant from the evaporator

48

is led, wherein the coolant from the tube path

49

is returned to the compressor

44

and circulated.

The air supplied from the working chamber

9

to be dehumidified passes through the tube path

25

, from which air a hazardous and toxic gas is absorbed and removed by a filter

50

such as activated carbon, and which air is cooled by the evaporator

48

, led to a dehumidifying processing section

54

of the dehumidifying means

42

via a tube path

51

, a fan

52

and a tube path

53

, and subjected to dehumidification.

The air having been dehumidified by the dehumidifying means

42

is led to the header

28

via a tube path

55

, a fan

56

and a tube path

57

.

The compression refrigerating machine

41

is further provided with an evaporator

58

serving as a pre-cooler disposed in relation to the air take-in means

43

for taking in the outside air. An expansion valve

59

is connected to this evaporator

58

after the condenser

45

and the tube path

46

, and a coolant adiabatically expanded at this expansion valve

59

is led to the evaporator

58

. The coolant coming from the evaporator

58

is returned into the tube path

49

. The pre-cooler

58

cools the outside air, which is injected into the air supplied from the working chamber

9

via the fan

52

on the upstream side of the dehumidifying means

42

, whereby the working chamber

9

is kept at the positive pressure as mentioned above.

FIG. 8

is a simplified perspective view of a configuration of the dehumidifying means

42

. This dehumidifying means

42

has a dehumidifying rotor

61

. The dehumidifying rotor

61

, whose overall shape is substantially cylindrical, is driven by a motor

63

to rotate about an axial line

62

thereof in one direction

64

.

FIG. 9

is an enlarged front view of part of the dehumidifying rotor

61

. The dehumidifying rotor

61

, which is made of a base material carrying a dehumidifying agent, has a lot of gas through holes elongated in the direction of the axial line

62

. This dehumidifying rotor

61

may be an activated carbon rotor made by soaking laminated activated carbon sheets with lithium chloride, or may be a silica gel rotor made by bonding silica gel to ceramic fiber paper in chemical synthesis, for example.

An air guiding means

65

has a casing

66

as shown in

FIG. 8

, and at both ends of the dehumidifying rotor

61

in the direction of the axial line

62

(end portions in the vertical direction of FIG.

8

), in the peripheral direction of the dehumidifying rotor

61

, along a rotation direction

64

, the dehumidifying processing section

54

, a regenerating section

67

and a purging section

68

are formed in this order divided by divider boards which are not shown.

FIG. 10

is a simplified front view of the dehumidifying rotor

61

. The area ratio in a plane vertical to the axial line

62

of the dehumidifying rotor

61

, that is, the ratio of air flow rate among the processing section

54

, the regenerating section

67

and the purging section

68

may be approximately 5 to 2 to 1.

To the regenerating section

67

, air for regeneration use from outside is supplied through a tube path

71

via a filter

70

and a regenerating heater

72

such as an electric heater in which the air is heated up to approximately 140° C., for example, and through a tube path

73

in the opposite direction to an air flow direction in the dehumidifying processing section

54

(from top to bottom in FIGS.

1

and

8

), and then flowed down. The air for regeneration use, supplied from the dehumidifying rotor

61

is dissipated outside by a fan

75

through a tube path

74

and a tube path

76

.

As air for purging which is supplied to the purging section

68

, part of the air returned to the working chamber

9

via the fan

56

and the tube path

57

is used. This purging air is branched from the tube path

57

and supplied through a tube path

78

in the opposite direction to the air flow direction in the dehumidifying processing section

54

(from top to bottom in FIGS.

1

and

8

). The purged air supplied from the dehumidifying rotor

61

is led and returned through a tube path

79

into the tube path

71

on the upstream side of the heater

72

.

FIG. 11

is a block diagram showing an electrical configuration in the embodiments of the invention shown by

FIGS. 1

to

10

. Dew point detecting means

81

is placed within the working chamber

9

, to detect a dew point or humidity of the dehumidified air. The dew point detecting means

81

may be placed on the header

28

, which is on the upstream side of the working chamber

9

, or may be placed on the header

24

and the like, which is on the downstream side of the working chamber

9

. A processing circuit

82

implemented by a microcomputer and the like responds to an output of the dew point detecting means

81

, and when the dew point exceeds a predetermined value, the circuit controls to increase a rotation speed of the motor

63

for driving the dehumidifying rotor

61

, or raise a heating temperature of the heater

72

which heats the air for regeneration use. When the detected dew point is lower than the predetermined temperature, the circuit controls to decrease the rotation speed of the motor

63

, or lower the temperature for heating the air for regeneration use by the heater

72

. Both the motor

63

and the heater

72

may be controlled by the processing circuit

82

, depending on the detected dew point.

In the air take-in means

43

, air coming in through the filter

70

is branched to a tube path

84

on the upstream side of a joint between the tube path

71

and the tube path

79

, led to the pre-cooler

58

where the air is cooled, mixed with the circulating air supplied through the tube path

51

, and sucked in by the fan

52

.

In the working chamber

9

, pressure detecting means

85

for detecting the air pressure in the working chamber

9

is mounted. In order that the detected pressure becomes a predetermined value higher than the atmospheric pressure, the processing circuit

82

controls the rotation speed of the fan

52

and controls the flow rate of the air sucked in from outside. For example, when the detected air pressure is below the predetermined value, the fan

52

is controlled so as to increase the rotation speed, and when the detected pressure exceeds the predetermined value, the rotation speed of the fan

52

is decreased due to the performance of the processing circuit

82

.

In another embodiment of the invention, at some midpoint in the tube path

84

, a flow control valve

86

shown in

FIG. 1

may be interposed. This flow control valve

86

is designed to control the flow rate of the air sucked in from outside in accordance with the detected pressure in the same manner as the fan

52

.

FIG. 12

is a block diagram showing an overall configuration of dehumidifying means

42

a

in another embodiment of the invention. Respective components used in this embodiment are similar to the components used in the embodiments shown by

FIGS. 1

to

11

, and those used in this embodiment corresponding to those used in the embodiments shown by

FIGS. 1

to

11

are denoted by the same reference numerals. It should be noted that a plurality of (two, in this embodiment) dehumidifying pipes

91

,

92

are placed in this embodiment. Into these dehumidifying pipes

91

,

92

, a dehumidifying agent such as silica gel is filled. To these dehumidifying pipes

91

,

92

, the air from the working chamber

9

is supplied via open/close valves V

2

, V

4

, and the dehumidified air is returned to the working chamber

9

via open/close valves V

1

, V

3

and the fan

56

, and circulated. To the dehumidifying pipes

91

,

92

, the air for regeneration use, heated by the heater

72

is supplied through the tube path

73

via open/close valves V

5

, V

7

in order to regenerate the dehumidifying agent. The air having been used for regeneration use is passed through open/close valves V

6

, V

8

, sucked in by the fan

75

, and exhausted through the tube path

74

. Into the tube path

25

, the outside air is sucked and mixed through the tube path

84

via the flow control valve

86

, and the pressure in the working chamber

9

is controlled so as to become a predetermined value higher than the atmospheric pressure.

The open/close valves V

1

to V

8

are controlled so as to repeatedly open and close at predetermined periods of time, that is, at a period of time t1-t2 and a period of time t2-t3 as shown in a time chart of FIG.

13

. Thus, while one dehumidifying pipe

91

is dehumidifying the air inside the working chamber

9

, the dehumidifying agent of the other dehumidifying pipe

92

is regenerated. Such an operation is alternately repeated at the periods of time t1-t2 and t2-t3. Other components in the embodiment shown in

FIGS. 12 and 13

are the same as those in the embodiments as shown before.

FIG. 14

is a simplified perspective view of a low-humidity working apparatus

7

a

in still another embodiment of the invention. The housing

8

is formed into a right circular cylinder, inside of which the working chamber

9

is formed. The housing

8

is provided with the arc-shaped elongated operating hole

30

along the outer region thereof. This operating hole

30

is provided with sealing means

36

composed of a lot of sealing members

37

in the same manner as in the embodiments shown above. In the vicinity of and above the operating hole

30

, the window hole

31

for enabling to view the working chamber

9

is formed, and the window hole

31

is closed by the light-transmitting window plate

32

. The window hole

31

is also formed into an arc in the same manner as the operating hole

30

. Other components are the same as in the embodiments shown above. The housing

8

may have a still another shape.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and the range of equivalency of the claims are therefore intended to be embraced therein.

INDUSTRIAL APPLICABILITY

According to the invention of claim

1

, the operating hole

30

which allows the worker to insert both of his (her) upper limbs at a time is formed on the surrounding wall of the housing

8

, and at least a portion of the housing in a vicinity above or alongside the operating hole

30

of the surrounding wall is designed to transmit light, whereby the worker can insert an item, jig or the like to be worked with his(her) upper limbs into the working chamber

9

through the operating hole

30

, and conduct an operation viewing the interior of the working chamber

9

from outside the housing via the light-transmitting portion, and hence the workability is excellent.

Further, water vapor is absorbed from the air inside the working chamber

9

by the dehumidifying agent in the dehumidifying means

42

, the dehumidified air is returned to the working chamber

9

, and the air is thus circulated, so that it is possible to keep the working chamber

9

in low-humidity condition at good efficiency.

Furthermore, on the upstream side of the dehumidifying means

42

, the outside air is sucked in and mixed, whereby the working chamber

9

is kept at positive pressure. Therefore, it is ensured to minimize the amount of high-humidity outside air entering the working chamber

9

, and keep the interior of the working chamber

9

in low-humidity condition at all times in a stable manner.

Thus, the dew point of the air in the working chamber

9

can be kept at −20° C. or less, for example, in the range of −20° C. to −70° C. Under such a condition, in the case where a person goes into, his (her) eyes get dry, the mucous membrane of his (her) nose and his(her) lips get cracked, and he/she easily gets infected with a common cold virus, but in the invention, only both of his(her) upper limbs are inserted into the working chamber, so that the worker's body would not be adversely affected.

Thus, it is possible to conduct an operation in the working chamber at good efficiency and an excellent workability.

According to the invention of claim

2

, the circulated air and the air supplied from outside are cooled by the cooling means

48

,

58

, and thereafter supplied to the dehumidifying means

42

, so that the dehumidification efficiency is more enhanced.

According to the invention of claim

3

, two evaporators

48

,

58

arranged in parallel in the compression refrigerating machine

41

are used as cooling means, so that the circulated air and the air supplied from outside are cooled at good efficiency.

According to the invention of claim

4

, the operating hole

30

is provided with the sealing member, so that it is possible to minimize the amount of low-humidity air released from the operating hole

30

, and it is thereby possible to minimize the amount of air supplied from outside.

According to the invention of claim

5

, the operating hole

30

is closed by a plurality of strip sealing members

37

which are drooped down, so that a portion around the upper limbs inserted through the operating hole

30

is closed by the suspended sealing members

37

. Further, the bottom end of the sealing member

37

is slightly above the bottom end of the operating hole

30

, and therefore the bottom end of the sealing member

37

would not on the inner side of the working chamber

9

or the outer side of the housing

8

than the bottom end of the operation hole

30

, whereby a gap would not be produced between the adjacent sealing members

37

, and the operating hole

30

can be closed with a minimum gap. Thus, the operating hole

30

is sealed without impairing the operability.

According to the invention of claim

6

, the window hole

31

is formed in the vicinity above or alongside the operating hole

30

, to which window hole

31

the window plate

32

made of light-transmitting material is hermetically secured. Therefore, the worker can easily view the interior of the working chamber

9

from outside the housing

8

.

According to the invention of claim

7

, the vertical height H

1

of the operating hole

30

is set to the dimension mentioned above, whereby the operator can insert his (her) upper limbs into the operating hole

30

in a comfortable position, and continue the operation in the working chamber

9

at an excellent workability without necessity of increasing the size of the operating hole

30

. Further, the lateral length L

1

of the operating hole

30

is set to the dimension mentioned above, whereby the worker can insert both of his(her) upper limbs at a time into the working chamber through the operating hole

30

, and conduct an operation with his(her) both hands, and hence the workability is excellent. In addition, since the operating hole

30

is formed laterally elongated as shown above, the worker can easily insert an item, jig or the like held by both of his (her) hands as it is into the working chamber

30

through the operating hole

30

or take it out, and hence the workability is excellent.

Furthermore, the height H

2

from the floor to the bottom end of the operating hole

30

is set to the dimension mentioned above, whereby the worker can raise and insert through the operating hole

30

in the above-described manner while he/she is sitting on a chair or standing on the floor, and conduct an operation in a stable and comfortable position. Further, as mentioned above, the lateral length L

2

of the window hole

31

and the lateral length L

1

of the operating hole

30

are designed to be nearly equal to each other, so that the worker can view the interior of the working chamber

9

from outside the housing

8

through the window hole

31

in the range of moving his (her) upper limbs, and hence the workability is excellent. The worker does not need to move his (her) head and eyes to view an operation status within the working chamber

9

.

According to the invention of claim

8

, it is possible to remove dust from the low-humidity air by the dustproof filter

29

, and due to a pressure loss of the filter

29

, ensure a uniform distribution of flow rate of the low-humidity air supplied into the working chamber

9

through the leading hole

11

. Thus, it is possible to keep a uniform humidity distribution in the working chamber

9

.

According to the invention of claim

9

, the air supplied from the leading hole

11

formed above the ceiling or the like of the working chamber

9

is exhausted from the exhausting hole

14

formed at the bottom of the working chamber

9

, for example, on the floor of the working chamber

9

, whereby dry air can be flowed at a uniform flow rate within the working chamber

9

from top to bottom without turbulence. Thus, it is possible to entirely keep the interior of the working chamber

9

in a low-humidity condition, and minimize variations of humidity.

According to the invention of claim

10

, the air pressure in the working chamber

9

detected by the pressure detecting means

83

is subjected to negative feedback control so as to become the predetermined value higher than the atmospheric pressure, so that it is possible keep the air pressure in the working chamber

9

at the predetermined positive pressure at all times. Therefore, there is no risk of leaking out the low-humidity air in the working chamber

9

in large amount, and the amount of the outside air entering the working chamber

9

can be minimized.

According to the invention of claim

11

, the dehumidifying means

42

includes the dehumidifying rotor

61

, and the respective sections of the dehumidifying rotor

61

form the dehumidifying processing section

54

, the regenerating section

67

and the purging section

68

in this order in accordance with the rotation of the dehumidifying rotor

61

, whereby it is possible to sequentially dehumidify the circulated air in the working chamber

9

.

Since the purging section

68

is provided, the dehumidifying rotor

61

would not shift from the regenerating section

67

directly to the dehumidifying processing section

54

, and hence the air for regeneration use which entered the dehumidifying rotor

61

at the regenerating section

67

is replaced with air of the purging section

68

which is low-humidity air, and thereafter the rotor shifts to the dehumidifying processing section

54

, so that low-humidity air can be supplied from the dehumidifying processing section

54

at all times.

Number	Name	Date
5228313	Okamoto et al.	Jul 1993
5937667	Yoho, Sr.	Aug 1999
5979170	Thorpe	Nov 1999
6094835	Cromer	Aug 2000
6138470	Potnis et al.	Oct 2000

Low-humidity working apparatus

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Abstract

Description

Claims

Priority Claims (1)

PCT Information

US Referenced Citations (5)