DESCRIPTION
Title of Invention
LOCAL AIR CLEANING APPARATUS
5 Technical Field
[('ow The present invention relates to a local air cleaning apparatus.
Background Art
r0(W Conventionally, a clean bench is o h used as an apparatus for improving
air cleanliness of a local work space. In a typical clean bench, only a front side of the
10 work bench has an opening for performing work and sides thereof other than the h n t
side form an enclosure in order to maintain cleanliness. In such a clean bench, a clean
air outlet is arranged in the enclom, and a worker puts his or her hands therein from the
front opening for working to perform work.
[0003] However, the opening for working in the clean bench is narrow.
15 Accordingly, for workers performing the assembly of precision instrument or the like,
there is a problem with workability. In addition, as in a production line, when work
involves the transfer of manufactured articles or manufacturing components, procedures
such as mgernent of the entire line in the clean room have been taken. This is,
however, problematic in terms of increasing the size of equipment.
20 [0004] Therefore, a local air cleaning apparatus has been proposed in which air
flow opening faces of a pair of push h d s capable of blowing out a uniform flow of
cleaned air are arranged opposite to each other to cause collision of air flows from the
respective air flow opening faces so as to allow a region between a pair of push hoods to
be a clean air space having higher cleanliness than other regions (Patent Literature 1).
25 Citation List
Patent Literature
[0005] Patent Literature 1 : Unexamined Japanese Patent Application Kokai
Publication No. 2008-275266
Swnmary of Invent ion
Technical Problems
[0006] Meanwhile, depending on the kind of work and the procedures of work, it
5 may be desirable in some cases to work in a little larger clean air space. In addition, it
may be occasionally desirable to work using a bcal air cleaning apparatus having a little
simpler structure. Therefore, there has been a desire for a local air cleaning apparatus
having a simpler structure.
[0007] The present invention has been accomplished in view of the above problems,
10 and it is an objective of the present invention to provide a lo& air cleaning apparatus
having a simple structure.
Solution to Problems
[OOOS] In order to achieve the above objective, a local air cleaning apparatus of the
present invention comprises:
15 a push hood comprising an air flow opening face for blowing out a cleaned
uniform air flow and
a guide provided on a side of the push hood comprising the air flow opening face,
the guide extending from the side thereof comprising the air flow opening hce toward a
downstream side of the uniform air flow to form an opening face at an downstream-side
20 end portion of the guide, wherein
the push hood is m g e d such that the cleaned uniform air flow blown out from
the air flow opening face passes through the inside of the guide and then wllides with an
air collision face on a downstream side of the opening face of the guide;
the opening face of the guide is spaced apart from and oppossd to the air collision
25 face to form an open region between the opening face of the guide and the air collision
face; and
the cleaned uniform air flow blown out h m the air flow opening face wllides
with the air collision f k e to flow out of the open region so as to cause the inside of the
guide and the inside of the open region to have higher cleanliness than other regions.
woo91 Preferably, the opening face of the guide and the air flow opening face of the
push h d are of substantially the same shape.
5 The push hood comprises, for example, a plurality of push hoods connected
together.
Preferably, the cleaned unifonn air flow blown out h m the air flow opening hce
has a flow rate of 0.2 to 0.5 d s .
The opening face of the guide has a width of, for example, 2 m or more and less
10 than 10 m. In this case, preferably, the distance between the opening face of the guide
and the air collision face is a distance over which the uniform air flow blown out from the
opening face collides with the air collision fke within 4 seconds.
The opening face of the guide has a width of, for example, 1 rn or m oan~d l ess
than 2 m. In this case, preferably, the distance between the opening face of the guide
15 and the air collision face is a distance over which the uniform air flow blown out from the
opening face collides with the air collision hce within 3 seconds.
The opening face of the guide has a width of, for example, 0.2 rn or more and less
than 1 m. In this case, preferably, the distance between the opening face of the guide
and the air collision face is a distance over which the uniform air flow blown out from the
20 opening face collides with the air collision face within 2 seconds.
[0010] Preferably, the air coliision face has a bent portion bent toward the guide
side near positions opposing end portions of the opening face of the guide.
In such a local air cleaning apparatus,
the opening face of the guide has a width of, for example, 2 m or more and less
25 than 10 m, and, preferably, the distance between the opening face of the guide and the air
collision face is a distance over which the uniform air flow blown out h m the opening
face collides with the air collision face within 6 seconds.
In addition, the opening face of the guide has a width of, for example, 1 m or more
and less than 2 m, and, preferably, the distance between the opening face of the guide and
the air collision face is a distance over which the uniform air flow blown out from the
opening face collides with the air collision face within 5 seconds.
5 Furthermore, the opening face of the guide has a width of, for example, 0.2 m or
more and less than 1 m, and, preferably, the distance between the opening face of the
guide and the air collision face is a distance over which the uniform air flow blown out
from the opening face collides with the air collision face within 3 seconds.
Advantageous Effects of Invention
10 [001i] The present invention can provide a local air cleaning apparatus having a
simple structure.
Brief Description of Drawings
[0012] FIG. 1 is a view depicting a I d air cleaning apparatus according to an
embodiment of the p m t invention;
15 FIG. 2 is a view depicting the structure of a push hood,
FIG. 3 is a view depicting another example of the local air cleaning appamtus;
FIG. 4 is a view i l l u d n g the stream of a cleaned uniform air flow;
FIG. 5 is a view depicting another example of the local air cleaning apparatus;
FIG. 6 is a view depicting another example of the local air cleaning apparatus;
FIGS. 7 are views illustrating the width of the opening face of the guide;
FIG. 8 is a view depicting a local air cleaning apparatus according to another
embodiment of the invention;
FIG. 9 is a view depicting a local air cleaning apparatus according to another
embodiment of the invention;
25 FIG, 1 0 is a view depicting a local air cleaning apparatus according to another
ernhdiment of the invention;
FIG. 1 1 is a view depicting a local air cleaning apparatus according to another
embodiment of the invention;
FIG. 12 is a view depicting measurement positions of Example 1;
FIG. 13 is a view depicting conditions for Examples 2 to 10;
FIG. 14 is a view depicting measurement positions of Examples 2 to 1 0;
5 FIG. 15 is a view depicting conditions for Examples 1 i to 1 9 and Reference
Examples 1 to 9;
FIG. 16 is a view depicting a local air cleaning apparatus and measurement
positions for Examples 20 and 2 1 and Reference Examples 10 and 1 1 ; and
FIG. 1 7 is a view depicting a local air cleaning apparatus and conditions for
1 0 Examples 20 and 2 1 and Reference Examples 10 and 1 1.
Description of Embodiments
[~131 Hereinafter, a local air cleaning apparatus according to the present invention
will be described with reference to the drawings. FIG. 1 is a view depicting an example
of a local air cleaning apparatus according to an emkliment of the present invention.
15 [0014] As depicted in FIG. 1, a local air cleaning apparatus 1 of the present
invention comprises a push hood 2 arranged so as to be opposed to an air collision face
W such as a wall or a partition screen and a guide 3 provided on the push hood 2.
[ ~ 1 5 1 The push hood 2 can be any push hood as long as the push h d has a
mechanism for blowing out a cleaned uniform air flow. As a structure of the push hood,
20 there can be employsd a structure in which a cleaning filter is incorporated in a basic
stntcture of a push hood conventionally used in push-pull ventilators.
[00 1 61 The terms uniform air flow and uniform flow d herein have the same
meaning as uniform flow described in "Industrid Ventilation" by Taro Hayashi
(published by the Society of Heating, Air-conditioning and Sanitary Engineers of Japan,
25 1982) and refer to a flow having a minute air flow rate, which is uniformly continuous
and causes no large whirling portion. However, the present invention d m not intend to
provide an air blowout apparatus strictly specifying an air flow rate and a velocity
distribution. In the uniform air flow, for example, a variation in a velocity distribution
in a state without obstacles is preferably within f 5P/, and furthermore within SO%,
with respect to the average value.
[OO 1 71 In the push h d 2 of the present embodiment, respective nine (longitudinal
5 three pieces x transversal three pieces) push hods are connected by a connector in such a
manner that the air flow opening fkes of the push hoods are oriented in the same
dbection and short sides and long sides, respectively, of the push h d s are arranged
adjacent to ach other. Herein, structures of the push h d s connected by the connector
are basically the same. Accordingly, a description will be given of the structure of a
10 push hood 2a as one of the push hoods, thereby describing the structure of the push hood
2 of the present embodiment. FIG. 2 depicts the structure of the push hood 2a.
~o(w As depicted in FIG. 2, a housing 21 of the push hood 2a is formed into a
substantially rectangular parallelepiped shape, and an air flow suction face 22 is formed
on one surface of the housing 21. The air flow suction face 22 comprises, for example,
15 a face having a plurality of holes formed entirely on the one surface of the housing 2 1.
Through the holes, the air flow suction face 22 takes in an outside air or a room air, which
is a m u n d ' i g air outside the push hood 2a In addition, on the other surface of the
housing 2 1 opposing the air flow suction face 22 is formed an air blowout hce (an air
flow opening h) 23. The air flow opening face 23 comprises, for example, a face
20 with a plurality of holes formed entirely on the one surface of the housing 21. Throu&h
the holes, the air flow opening face 23 blows out the uniform air flow of a cleaned air
formed in the push hood 2a to the outside of the push hood 2a. The dimensions of the
air flow opening face 23 of the push hood 2a are not particularly limited, for example,
1050 x 850 mm.
25 [0019] The push hood 2 is arranged such that the air flow opening face thereof is
opposed to an air collision face W such as a wall. Herein, the description ''the air flow
opening face is opposed to the air collision f h W' means not only a state in which the
air flow opening face 23 of the push food 2 and the air collision face W are opposed in
parallel to each other, but also, for example, a state in which the air flow opening face 23
of the push food 2 and the air collision face W are slightly inclined from each other, as
depicted in FIG. 3. Regarding the inclination between the air flow opening face 23 of
5 the push hood 2 and the air colf ision face W, an angle formed by the air flow opening
face 23 and the air collision fke W is preferably in a range of about 30 degrees.
[0020] In the housing 21 are arranged an air blowing mechanism 24, a high
performance filter 25, and a rectification mechanism 26.
The air blowing mechanism 24 is arranged on a side where the air flow suction
10 face 22 is located in the housing 21. The air blowing mechanism 24 comprises an air
blowout fan and the like. The air blowing mechanism 24 takes in an outside air or a
room air, which is the smunding air of the push hood 2% h m the air flow suction face
22 and blows out an air flow from the air flow opening face 23. In addition, the air
blowing mechanism 24 is configured to control a blowout force of the fan so as to allow
15 the flow rate of an air flow blown out from the air flow opening f h 23 to be changed.
[m2 1 1 The high performance filter 25 is arranged between the air blowing
mechanism 24 and the rectification mechanism 26. The high performance filter 24
comprises a high performance filter in accordance with a cleaning level, such as a HEPA
filter (High Efficiency Particulate Air Filter) or an ULPA filter (Ultra Low Penetration
20 Air Filter) for filtrating the surrounding air taken in. The high performance filter 25
cleans the surrounding air taken in by the air blowing mechanism 24 into a clean air
having a desirable cleaning level. The clean air cleaned to the desirable cleaning level
by the high performance filter 25 is sent to the rectification mechanism 26 by the air
blowing mechanism 24,
25 [0022] The rectification mechanism 26 is arranged between the high performance
filter 25 and the air flow opening face 23. The rectification mechanism 26 is provided
with a not-shown air resistor, which is formed using a punching plate, a mesh member,
andor the like. The rectification mechanism 26 corrects (rectifies) a blown air sent
from the higher performance filter and having an amount of aeration biased with respect
to the entire part of the air flow opening face 23 into a miformized air flow (a uniform air
flow) having an amount of aeration unbiased with respect to the entire part of the air flow
5 opening face 23. The uniform air flow rectified is blown out by the air blowing
mechanism 24 h m the entire part of the air flow opening face 23 to the outside of the
push hood 2.
[0023] In addition, as depicted in FIG. 2, the push h d 2a is preferably provided
with a pre-filter 27 between the air flow suction face 22 and the air blowing mechanism
10 24 in the housing 2 1 . An example of the pre-filter 27 may be a medium performance
filter. The arrangement of the pre-filter 27 between the air flow suction k e 22 and the
air blowing mechanism 24 allows removal of relatively large dust particles contained in a
surrounding air sucked into the housing 21 through the air flow suction face 22. In this
manner, dust parhcles can be removed in multiple stages in accordance with the size of
15 dust particles contained in the surrounding air. Accordingly, the performance of the
high performance filter 25 easily causing clogging or the l i e can be maintained for a
long period,
Po241 In the push hood 2a thus formed, the mundiig air taken in by the air
blowing mechanism 24 is cleaned into a clean air having a desirable cleaning level by the
20 pre-filter 27 and the high performance filter 25. Then, the clean air obtained by the
cleaning is rectified into a uniform air flow by the rectification mechanism 26, The
uniform air flow thus cleaned is blown out externally from the entire part of the air flow
opening face 23 in a direction substantially vertical to the air flow opening face 23 of the
push h d 2a.
25 [0025] One end of the guide 3 is provided on the side of the push hood 2 having the
air flow opening face 23. In addition, the guide 3 is provided on the air flow opening
face 23 and formed in such a manner as to extend therefrom toward the downstream side
of the uniform air flow blown out from the air flow opening face 23 and cover an outer
peripheral outline portion of the air flow opening face 23. For example, when the air
flow opening face 23 is rectangular, the guide 3 is formed to be extended so as to have a
U-shaped. With an open side of the U-shaped and a floor, the guide 3 including the
5 outer peripheral outfine portion in a blowout direction of the uniform air flow surrounds,
like a tunnel, the periphy of an air flow in parallel to a stream of the uniform air flow
blown out from the air flow opening face 23, Additionally, when there is no floor, the
guide 3 is formed to be extended so as to have, for example, a square cross-sectional
shape, not a U-shaped. The guide 3 is formed so as to have an open region between the
10 other end thereof (the opening face 3 1) and. Herein, the opening face 3 1 of the guide 3
refers to a hollow end face, namely an opening, which is smunded by the peripheral
edge outhe of a downstream-side end portion (a boundary with the open region) of the
guide 3 extending like the tunnel toward the downstream side of the uniform air flow
blown out from the air flow opening face 23. For example, in a case of substituting the
15 floor for a part of the guide 3, when the cross section of the guide 3 is U-shaped, a square
hollow opening fmed by the downstream-side end portion of the guide 3 and the floor
corresponds to the opening face 3 1. When the cross section of the guide 3 is square, a
square hollow opening fonned at the dowtream-side end portion of the guide 3
corresponds to the opening face 3.
20 [0026] The guide 3 can be formed using an arbitrary material as long as an air flow
blown out from the opening face 3 1 can maintain the state of a cleaned uniform air flow
blown out from the air flow opening hce 23. In addition, the guide 3 does not
necessarily have to completely cover the entire periphery of the uniform air flow as long
as the state of the cleaned uniform air flow blown out from the air flow opening face 23
25 can be maintained. For example, a hole may be opened or a slit may be formed in a part
of the guide 3.
[0027] The guide 3 is m g e d such that the opening face 3 1 thereof is opposed to
the air collision face W. By arranging the guide 3 such that the opening face 3 1 is
opposed to the air collision face W, an air flow blown out from the opening face 3 1
collides with the air collision face W. As depicted in FIG. 4, when the opening face 3 1
is opposed in parallel to a wall, the uniform air flow collides with the air collision face W
5 and then exhibits a behavior of changing the direction of the flow substantiaIly vertically .
By flowing in such a manner, the air flow, after having collided with the air collision face
W, flows outside the face with which the air flow collided. As a result, a clean space
can be obtained in a region from the collision face of the air flow to the end portion of the
opening face 3 1,
10 [0028] Herein, the description "the opening face 3 1 is o p p d to the air collision
face W' means not only a state in which the opening face 3 is opposed in parallel to the
air collision face W, but also, for example, a state in which the opening face 3 1 of the
guide 3 and the air collision fax are slightly inclined from each other, as depicted in FIG.
3, This is bemuse even in the state in which the air flow blown out from the opening
15 face 3 1 does not collide h d on with the air collision face W, a clean space can be
formed in a space surrounded by a dotted line in FIG. 3. An angle formed by the
opening face 3 1 of the guide 3 and the air callision face W is preferably in a range of
about 30 degrees.
[a0291 Preferably, the opening face 3 1 is formed so as to have substantially the
20 same shape as the air flow opening face 23. This is because when the opening face 3 1
and the air flow opening face 23 are formed to have substantially the same shape, the
state of a uniform air flow blown out fmm the air flow opening fke 23 can be easily
maintained in the opening face 3 1. However, the shapes of the opening face 3 1 and the
air flow opening face 23 do not necessarily have to k substantially the same. For
25 example, as depicted in FIGS, 5 and 6, the width of the opening face 3 1 may lx increased
or reduced to differentiate the shapes of the opening face 3 1 and the air flow opening face
23 from each other, because even in this case, the state of the uniform air flow can be
maintained. In the increase or reduction of the width of the opening face 3 1, (width of
opening face 3 l)/(width of air flow opening face 23) is preferably 0.6 to 1,4 and more
preferably 0.8 to 1.2. By setting the width ratio in the abve range, the state of the
uniform air flow blown out from the air flow opening face 23 can be maintained in the
5 opening f8ce 31.
[0030] A length b of the guide 3 can be any length as long as an open region can be
fonned between the opening face 3 1 of the guide 3 and the air collision face W when the
opening face 3 1 thereof and the air collision face W are spaced apart from and opposed to
each other. Preferably, the length b of the guide 3 is set to a predetermined length
10 according to a distance X between the air flow opening face 23 of the push hood 2 and
the air collision face W, the flow rate of a unifonn air flow blown out h m the air flow
opening face 23 (the opening face 3 l), and the like.
[a03 1 ] As will be described below, when the length b of the guide 3 is 12 m, a
distance (X - b) between the opening face 3 1 of the guide 3 and the air collision face W
15 is preferably set to be not more than a distance of 4 times a flow rate (a distance over
which a uniform air flow blown out from the opening face 3 1 collides with the air
w11ision face W within 4 seconds) when the width of the opening face 31 is 2 m or more
and less than 10 m. In addition, when the width of the opening face 3 1 is 1 m or more
and less than 2 m, the distance (X - b) therebetween is preferably set to be not more than
20 a distance of 3 times a flow rate (a distance over which the uniform air flow blown out
from the opening face 3 1 collides with the air collision face W within 3 seconds).
Furthermore, when the width of the opening face 3 1 is 0.2 m or more and less than 1 m,
the distance (X - b) therebetween is preferably set to be not more than a distance of 2
times a flow rate (a d h c e over which the unifonn air flow blown out from the opening
25 face 3 1 collides with the air collision face W within 2 seconds). This is because setting
the distance (X - b) to the distances allows the inside of the guide 3 and the open region
between the opening face 3 1 and the air collision face W to have high cleanliness.
~ 3 2 1 Herein, when the opening face 3 1 is a circle, a width (L) of the opening face
3 1 refers to the diameter of the circle, as depicted in FIG. 7A. In addition, when the
opening face 3 1 is a rectangle, the width (L) of the opening fax 3 1 refers to the diameter
of a maximum circle inscribed in the rectangle, namely the length of a short side of the
5 rectangle, as depicted in FIG. 7B. In addition, when the opening face 3 1 is an oval or a
polygon, the width (L) of the opening face 3 1 refers to the diameter of a maximum circle
inscribed in each of the figures, as depict4 in FIGS. 7C to 7G. Furthermore, when the
opening face 3 1 has a shape including concave portions, the width (L) of the opening face
3 1 refers to the diameter of a circle inscribed at a position where the distance between
10 sides king each other is shortest, as depicted in FIG. 7H. Still furthermore, when the
opening face 3 1 has a shape with a concavity, the width (L) of the opening face 3 1 refers
to the diameter of a circle inscribed at a position where the distance between a side
having the concavity and a side facing the side is shortest, as depicted in FIG. 71.
COO331 The guide 3 thus formed is, as depictsd in FIG. 1, provided (attached) from
15 the side of the push hood 2 having the air flow opening face 23 toward the downstream
side of a uniform air flow and arranged such that the opening face 3 1 provided at the end
portion of the dowmlream side is oppossd to the air collision fkce W. In this manner, an
open region is formed between the opening fm 3 and the air collision face W.
~ 3 4 1 In the local air cleaning apparatus 1 thus formed, a surrounding air near the
20 air flow suction face 22 taken in by the air blowing mechanism 24 of the push hood 2 is
cleaned by the prefilter 27 and the high performance filter 25 into a clean air having a
desirable cleaning level. Then, the clean air obtained by the cleaning is rectified into a
uniform air flow by the rectification mechanism 26 and the cleaned uniform air flow is
blown out into the guide 3 h m the entire part of the air flow opening face 23.
25 lo0351 Herein, the cleaned uniform air flow blown out h m the air flow opening
face 23 has s flow rate of preferably 0.3 to 0.5 d s . In order to suppress power
consumption, the air velocity can be reduced to 0.2 to 0.3 mls. When the inside of the
local air cleaning apparatus 1 is contaminated and quick cleaning is desirable, the air
velocity can be reduced to 0.5 to 0.7 d s . Accordingly, the flow rate of the cleaned
uniform air flow can be selected as needed. This is because, by blown out at these flow
rates, the cleaned unifonn air flow blown out from the air flow opening fbx 23 moves
5 through the inside of the guide 3 as if extruded and the state of the unifonn air flow can
be easily maintained in the guide 3. Additionally, slowing the flow rate can reduce the
number of rotation of the fan of the air blowing mechanism, whereby noise level and
power consumption can be suppressed. Due to the reduction, the volume of air blown is
reduced, which can thus reduce the amount of dust accumulated on the pre-filter 27 and
10 the high performance filter 25. On the other hand, in a situation in which contaminants
are generated in a cleaned space of the guide 3, setting the flow rate of the uniform air
flow to about 0.5 mls allows the contaminants in the guide 3 and in the open region
formed between the guide 3 and the air collision fixe W to be removed more quickly than
- at a flow rate of the unifonn air flow of 0.2 d s . Thus, the flow rate of the uniform air
15 flow can be freely set according to the purpose of use. Meanwhile, an excessive
increase in the air velwity of the uniform air flow blown out fi-om the air flow opening
face 23 leads to the murrence of a whirling portion, and when the uniform air flow is
blown out from the opening face 3 1, turbulence can occur and thereby contaminants
outside the open region may be rolled up into the open region formed between the guide
20 3 and the air collision face W. Accordingly, preferably, the air velocity of the d o r m
air flow blown out from the air flow opening face 23 is set to an air velocity that does not
cause any whirling portion.
The cleaned uniform air flow blown out to the guide 3 passes through the
guide 3 while maintaining the state of the uniform air flow and then is blown out from the
25 opening face 3 1. The air flow blown out from the opening fke 3 1 collides with the air
collision face W. The air flow, after having collided, flows outside the open region
formed between the guide 3 and the air collision face W (outside the local air cleaning
apparatus 1). As a result, the region between the air flow opening face 23 and the air
collision face W (the inside of the guide 3 and the open region between the opening face
3 1 and the air collision fk W) can have higher cleanliness than regions outside the local
air cleaning apparatus I .
5 [0037] Herein, a comparison was made between the present invention and the Imal
air cleaning apparatus described in Patent Literature 1. For the comparison, dimensions
of the air flow opening face of the push hood in both apparatuses were set to a width of
1050 mm and a height of 850 mm and nine push hoods ((longitudinal three pieces x
transversal three pieces) each having the air flow opening face were connected together.
10 In addition, the flow rate of a cleaned uniform air flow blown out h m the air flow
opening faces was set to 0.5 mls. In this case, in the I d air cleaning apparatus
described in Patent Literature 1, it was conf~rrnedth at the upper limit of the distance
between the air flow opening faces 23 obtained as a cleaned space was about 5.5 m. In
contrast, in the local air cleaning apparatus 1 of the present invention, it was mnfhned
15 that the distance between the air flow opening face 23 and the air collision face W
o w e d as a cleaned space can be increased up to about 20 m Thus, the local air
cleaning apparatus 1 of the present invention can have a simple structure and can form a
large clean air space.
~ ~ 3 8 1 In addition, cornpard to an open-type air cleaning apparatus using the
technology described in Patent Literature 1, even when the flow rates of uniform air
flows blown out from push hoods having the same area are the same, the present
invention can provide a considerably larger clean air space. Furthermore, since the
apparatus of the invention does not need a push fd on both sides, even when the power
consumption per push hood is the same, the amount of electricity consumed per unit area
in the clean air space can be reduced. Or when cleaning the same clean space, air
velocity can be slower than in Patent Literature I, and therefore the number of rotation of
the fan in the air blowing mechanism can be reduced, enabling the power consumption to
be ~duced. Then, since the air velocity can be slower, noise due to the operation of the
local air cleaning apparatus can dso be reduced. Additionally, since the volume of air
passing through the filters is reduced, the amount of dust accumulated on the filters for
obtaining a clean air is d u d , which can therefore suppress the exhaustion of the filters.
5 Furthermore, when the open-type local air cleaning apparatus of Patent Literatwe 1 was
installed under the above conditions, it was confirmed that power consumption was 7200
W and noise level was 75 dB(A) in the center between the air flow opening faces 23
opposed to each other. In contrast, in the apparatus of the present invention used under
the above installation condition (the distance between the air flow opening face 23 and
10 the air collision face W: 20 m), it was confirmed that power consumption was 3600 W
and noise level was equivalent to that in Patent Literature 1 above in the center between
the air flow opening face 23 and the air collision face W. In other words, in Patent
Literature 1, a space having a volume of about 45 cubic meters was cleaned and the
amount of electricity consumed for cleaning per cubic meter was about 160 W, whereas
15 the apmhu of the present invention was confirmed to have cleaned a space having a
volume of about 160 cubic meters and the amount of electricity consumed for cleaning
per cubic meter was c o h e d to be about 22.5 W. In addition, although the present
invention described above has exemplified the case in which the distance between the air
flow opening face 23 and the air collision face W is 20 m, increasing the distance can
20 lead to W e r reduction in the power wnsumption per unit volume.
[0039] Furthermore, in a typical clean room, the entire room is cleaned and it is
therefore not easy to perform construction work, whereas in the local air cleaning
apparatus I of the present embodiment, the push hood 2 can be easily moved. In
addition, the local air cleanifig apparatus 1 of the embodiment can significantly facilitate
25 layout changes in the work region, such as bending the guide 3 provided on the push
hood 2 depending on the work in a range that does not affect the uniform air flow and
moving an open region formed between the opening faces of the guides to an arbiposition.
1004 01 In addition, in the case of a typical clean room in which a worker himself or
herself enters a clean region to perform work, a work region for the worker is not
changed no matter how much distance between a floor on which the worker woks and a
5 ceiling with a clean air blowing apparatus is increased. However, in the local air
cleaning apparatus 1, a horizontal flow is used. Thus, an increase of a region in the
guide 3 can lead to an increase of a work region (floor area) for the worker himself or
herself entering the clean region to perform work.
[0041] Additionally, in the open region of the present embodiment, there are no
10 doors that allow a worker, a component, and a manufacturing machine to pass through,
necessary in a typical clean room. Thus, cleanliness reduction in the clean air region
caused by opening of the doors does not occur and going in-and-out of a worker and
carrying-in and -out of a component or the like can be always done through the open
1
region. In a typical clean room, when the inside of the clean room is contaminated,
15 contaminated air in the clean room is diluted with a clean air supplied to the clean room
and then exhausted to gradually clean the inside of the clean room. Accordingly, it
takes a couple of hours to clean the inside of a clean room when contaminated,
However, in the present invention, even if the inside of the guide 3 and the inside of the
open region are contaminated, a cleaned uniform air flow blown out from the air flow
20 opening face flows in such a manner as to extrude the contaminated air h m the inside of
the guide to the outside thereof, so that cleaning can be performed in an emmely short
time.
fW21 Additionally, in a typical clean room, the clean air supplied to the clean
room is discharged fiom an exhaust outlet provided in the clean m m or a small gap
25 formed between a wall face and the floor of the clean room. This is because a typical
clean room makes the gap as small as possible to allow the inside of the clean room to be
maintained under positive pressure so as to prevent contaminated air h m entering from
outside. However, d i k e the clean room that discharges clean air from the small gap,
the present invention can form an open region as large as possible and can clean also the
formed space. Accordhgly, the open region can be used as a door as mentioned above
or the like, as a cleaned region.
5 [a)431 As described above, according to the local air cleaning apparatus 1 of the
present emwiment, the push hood 2 provided with the guide 3 is arranged so as to be
opposed to the air collision face W, whereby the inside of the guide 3 and the open region
between the opening face 3 1 and the air collision f a e W can have higher cleanliness than
regions outside the local air cleatling apparatus 1. In this manner, the present invention
1 0 can provide the local air cleaning apparatus 1 having a simple mcture.
[ W j The present invention is, however, not limited to the above embodiment and
various modifications and applications can be made. Herekafbr, a description will be
given of other embodiments applicable to the present invention.
[00451 In the above embodiment, the present invention has been describd by
1 5 exemplifying the case in which the shape of the guide 3 provided on the push hood 2 is
straightly extended from the air flow opening face 23 of the push h a d toward the
opening face 3 1 of the guide. However, for example, as depicted in FIG. 8, the shape of
the guide 3 may be curved in a range that maintains the state of a uniform air flow.
Even in this case, the inside of the guide 3 and the open region W e e n the opening face
20 3 1 and the air collision face W can have higher cleanliness than regions outside the local
air cleaning apparatus 1, and a local air cleaning apparatus 1 having a simple structure
can be provided.
[0046] In the above embodiment, the present invention has been described by
exemplifying the case in which the push hood 2 includes, raptively, the nine
25 (longitudinal three pieces x transversal three pieces) push hoods 2a connected together by
a connector. However, the number of the push hoods 2a forming the push hood 2 may
be 10 or more, or 8 or less. For example, the push hood 2 may include, respectively,
four (longitudinal two pieces x transversal two pieces) push hoods 2a connected together
by a connector. When connecting the push h d s 2a as in these examples, the air flow
opening faces of the push hoods 2a are oriented in the same direction and short sides and
long sides, respectively, ofthe mutual push hoods 2a are arranged adjacent to each other.
5 In this case, preferably, the mutual push h d s 2a are connected together in such a
manner that side faces, upper and lower faces, or both of the side faces and the upper and
lower faces of the adjacent push h d s are in an airtight state, or the mutual push hoods
2a are connected together in an airtight state via a seal material such as a packing
interposed between the side faces, the upper and lower faces, or both thereof of the
10 adjacent push hoods 2a In addition, as depicted in FIG. 9, the push hood 2 may
comprise a single push hood 2a. Even in these cases, the inside of the guide 3 and the
open region between the opening face 3 1 and the air collision face W can have higher
cleanliness than regions outside the local air cleaning apparatus 1. Therefore, the local
air cleaning apparatus 1 having a simpler structure can be provided. Additionally, in the
1 5 local air cleaning apparatus 1, without using a floor as one face of the guide 3, the shape
of the guide 3 may be made square.
[0047] The above embodiment has described the present invention by exemplifying
the case in which, in the open region between the opening face 3 1 and the air collision
face W, the upper face and both side faces are open. However, for example, as depicted
20 in FIG. 10, the end portion of an upper face of the guide 3 may be connected to the air
collision face W to form a region in which only side faces are opem Even in this case,
the region between the air flow opening face 23 and the air collision Edce W can have
higher cleanliness than regions outside the local air cleatling apparatus 1, and a local air
cleaning apparatus 1 having a simple structure can be provided.
25 [OM81 While the abve embodiment has described the pmnt invention by
exemplifying the case in which the air collision face W is flat like a wall or a partition
screen, the air collision face W is not limited thereto. For example, preferably, the air
collision face W has a bent portion W 1 bent toward the side having the guide 3 (the push
hood 2) at end portions of the air collision face W, which are near positions opposing the
end portions of the opening face 3 1 of the guide 3, for example, at side portions of the air
collision face W, as depicted in FIG. 1 1. Alternatively, the air collision face W may
5 have a bent portion W 1 where all of the upper portion, the lower portion, and the side
portions thereof are bent toward the side having the guide 3. In addition, the bent
portion W 1 may have a rounded corner (have roundness on the corner) so as to have a
gently cuwed surface. Forming the bent portion W 1 in the air collision face W as above
facilitates prevention of the inflow of air from the outside of the open region formed
10 between the guide 3 and the air collision face W (outside the local air cleaning apparatus
1). Accordingly, the region between the air flow oping fke 23 and the air collision
face W (the inside of the guide 3 and the open region between the opening face 3 1 and
the air collision face W) can have higher cleanliness than regions outside the local air
cleaning apparatus 1, and there can be provided a local air cleaning apparatus 1 having a
15 simple structure. Furthermore, the distance between the opening fke 3 1 and the air
collision face W and the shortest distance between the end portion of the opening face 3 1
and the bent portion W 1 can be increased, so that a larger clean air space can be formed.
[om91 In addition, the push hood 2 may have a structure with casters on the bottom
thereof, In this case, the push h a d 2 can be easily moved. Additionally, the guide 3
20 may be a unit of a partition with casters, which has a shape flexibly connectable to the
push h d 2, where the unit may be covered with a vinyl sheet. In this case,
construction work can be easy and movement of the unit can also be easy. Furthennore,
the guide 3 may be formed like a vinyl house extensible in a stream direction of an air
flow in a shape of bellows. In this case, the length of the guide 3 can be easily changed,
25 the guide 3 can be easily bent, and the position of the guide 3, namely, a position for
obtaining a clean space can be easily changed.
[0050] For example, when forming a clean zone in a corner of a room, a side wall
face andor the floor may be substituted for a part of the guides 3.
In addition, when a part of a conveyor-like line is arranged in a clean space, the
part of the line intended to be cleaned may be entirely covered to be enclosed as in a
tunnel; then, a push h d 2 may be attached so as to be connected to one end of the
5 enclosed part of the line, whereas the other end thereof may be kept in an open state
(opening face 3 1) to arrange the air collision face W at a position opposing the open end.
In such an example, when the line is arranged along a wall, the wall can be substituted for
a part of the guide 3.
Examples
10 [OOSl] Hereinafter, the present invention will be described in more detail with
reference to specific ExampLes of the invention.
[m521 (Example 1)
Using the local air cleaning appamtw 1 depicted in FIG. 1, c l e d i s s was
measwed at measurement positions 1 to 15 (the inside of the guide 3 and the open region
1 5 between the opening face 3 1 and the air collision f h W) indicated in FIG. 12. FIG. 1 2
is a top view of the local air cl&g apparatus 1. The push hood 2 is formed by
connecting nine push hoods 2a (longitudinal three pieces x transversal three pieces) each
having a width of 1050 mm and a height of 850 mm in slach a manner that air flow
opening hca of the push hoods 2a are oriented in the same direction and short sides and
20 long sides, respectively, of the push hoods 2a are m v e l y arranged adjacent to each
other, The opening hce 3 1 has dimensions of a width of 3 150 rnm and a height of 2550
mm. The measurement height for the measurement positions 1 to 15 was at a position
of ID of the height of the push hood 2. Cleanliness was measured using LASAIR-II
manufactured by PMS Inc., to measure the number of dust particles (piecedCF) having a
25 particle size of 0.3 pm. Regarding cleanliness, cases with 300 piecedCF or less were
evaluated to be high in clanliness. The length b of the guide 3 was 10 m, the distance
X between the air flow opening face 23 of the push h d 2 and the air collision face W
was 12 m, and the flow rate of the cleaned uniform air flow was 0.5 m/s. In addition,
for reference, cleanliness was also similarly measured at measurement positions I6 to 1 8
outside the local air cleaning apparatus 1. Table 1 indicates the results.
[0053] (Example 1)
5 Table 1
~00541 As indicated in Table I , it was able to be coniirmed that arranging the push
hood 2 provided with the guide 3 in such a manner as to oppose the air collision face W
allowed the inside of the guide 3 and the open region between the opening face 3 1 and
the air collision face W to have higher cleanliness than the regions outside the local air
1 0 cleaning apparatus 1 . In this case, it was able to be confirmed that the power
consumption was 3600 W and the noise level was 75 dB(A) in the center between the air
flow opening face 23 and the air collision face W, thereby enabling the provision of a
local air cleaning apparatus 1 having a simple structure.
[OOSS] (Examples 2 to 10)
15 Using the local air cleaning apparatus 1 depicted in FIG. 1, cldiness was
measured for cases of changing the flow rate of a cleaned uniform air flow, the length b
of the guide 3, and the distance X between the air flow opening face 23 of the push hood
2 and the air collision fhce W, as depicted in FIG. 1 3. In Example 1, the inside of the
guide 3 was confirmed to have been cleaned. Thus, in Examples 2 to 1 0, cleanliness
20 was measured at seven points as respective measurement points A to G in the opening
face 3 1, at a position of 1 5 cm apart from the air wllision face W toward the side having
the opening face 3 1, and in the center between the opening face 3 1 and the air collision
face W, respectively, as depicted in FIG. 14. The results are given in Tables 2 to 1 0.
The positions of measurement points A, D, and E were at the positions of 15 crn
5 downward h m the upper edge of the downstream end portion of the guide 3 or the like
and 15 crn inward of an air flow from the side edges of the downstream end portion of the
guide. The positions of measurement points B and F were at an intermediate height
between the upper edge and the lower edge of the downstream end portion of the guide 3
or the like and at the positions of 15 cm inward of the air flow h m the side edges of the
10 downstream end portion of the guide. The positions of measurement points C and G
were at the positions of 15 cm upward in the guide h m the lower edge of the
downstream end portion of the guide 3 or the like and 15 cm inward of air flow from the
side edges of the downstream end portion of the guide. Additionally, the measurement
points A to G on the side having the air collision face W were at the positions of 1 5 crn
15 upstream of the air flow from the air wllision face W.
[0056] @wPI~ 2)
Table 2
[005q (Example 3)
Table 3
Measurement
pint
A
Number of dust particles (piecedCF)
Air collision face
W
0
Center
0
oping face
3 1
1
F)o58] (Example 4)
Table 4
Table 5
--
5 Iooml @mpIe 6)
Table 6
[006 11 (Example 7)
Table 7
[M21 m p l e 8)
Table 8
5 [0063] @ample 9)
Table 9
[ow] (Example 10)
Table 10
I Measurement I Number of dust micles (~iecedCF) I
[0065] As indicated in Tables 2 to 10, it was able to be confirmed that even when
changing the flow rate of the cleaned uniform air flow, the length b of the guide 3, and
the distance X between the air flow opening face 23 of the push hood 2 and the air
collision face W, the inside of the guide 3 and the open region between the opening face
5 3 1 and the air collision face W were able to have higher cleanliness than the regions
outside the local air cleaning apparatus 1. In addition, in this case, it was able to be
confirmed that the power consumption was 1062 to 3600 W and the noise level was 59 to
75 dB(A) in the center between the air flow opening face 23 and the air collision face W.
[0066] (Examples 1 1 to 19 and Reference Examples 1 to 9)
10 Using the local air cleaning apparatus 1 depicted in FIG. 1 (nine push hoods 2a:
longitudinal thm pieces x transversal three pi-, each having a width of 1050 mrn and
a height of 850 mrn), cleanliness was measured for cases in which the length b of the
guide 3 was set to 12 rn and the flow rate of a cleaned uniform air flow and the distance
(X - b) between the opening face 3 1 of the guide 3 and the air collision face W were
1 5 changed, as indicated in FIG. 1 5, (Examples 1 1 to 1 3 and Reference Examples 1 to 3).
In addition, using the local air cleaning apparatus 1 depicted in FIG. 9 (a single push h d
2a having a width of 1050 rnm and a height of 850 rnrn), cleanliness was similarly
measured (Examples 14 to 16 and Reference Examples 4 to 6). Furthemore, using a
local air cleaning apparatus 1 (four push hoods 2a: longitudinal two pieces x transversal
20 two pieces, each having a width of 1050 rnrn and a height of 850 mm), cleanliness was
similarly measured (Examples 1 7 to 19 and Reference Examples 7 to 9). The
measurement of cleanliness was performed by measuring the number of dust particles
(piecedCF) having a particle size of 0.3 pn using LASAIR-I1 manufactured by PMS Inc.,
and cases with 300 p i d C F or less were evaluated to be high in cleanliness (Judgment:
0).
Lo(w As indicated in FIG, 15, it was able to be confirmed that increasing the flow
5 rate of the cleaned uniform air flow and increasing the number of the push hoods 2a to
increase the width (short-side length) of the opening face 3 1 increased the distance
between the opening face 31 and the air collision face W that can be cleaned.
Specifically, it was able to be confirmed that when the number of the push h d s 2a was
nine (the width of the opening face 3 1 : 2650 mm), the inside of the guide 3 and the open
10 region between the opening face 3 1 and the air collision face W were able to have a high
cleanliness of 300 piWCF or less by setting the distance (X - b) between the opening
face 3 1 of the guide 3 and the air collision face W to be not more than a distance of 3 to 4
times the flow rate (a distance over which a uniform air flow blown out from the opening
face 3 1 collides with the air collision face W within 3 to 4 seconds). In addition, the
15 inside of the guide 3 and the open region ktween the opening face 3 1 and the air
collision face W were confmied to be able to have a high cleanliness of 300 pieceKF or
less, when the number of the push hoods 2a was four (the width of the opening face 3 1 :
1700 rnm), by setting the distance (X - b) to be not more than a distance of 2.4 to 3 times
the flow rate (a distance over which the uniform air flow blown out from the opening face
20 3 1 collidm with the air collision face W within 2.4 to 3 seconds), and when the number of
the push hoods 2a was one (the width of the opening face 3 1: 850 rnm), by setting the
distance (X - b) to be not more than a distance of 1.6 to 2 times the flow rate (a distance
over which the uniform air flow blown out from the opening face 3 1 collides with the air
collision face W within 1.6 to 2 seconds).
25 [0068] In the present Examples and Reference Examples, cases of 300 piecedCF or
less were evaluated to be high in cleanliness. However, for example, even a case of
1000 piedCF or less can also be evaluated to be sufficiently high in cleanliness. In
this case, when the width of the opening face is 2 m or more and less than 10 m, the
inside of the guide 3 and the open region between the opening face 3 1 and the air
collision face W can have high cleanliness by setting the distance (X - b) to lx not more
than a distance of 4 times the flow rate (a distance over which a uniform air flow blown
5 out from the opening face 3 1 collides with the air collision face W within 4 seconds). In
addition, the inside of the guide 3 and the open region between the opening face 3 1 and
the air collision face W can have high cleanliness, when the width of the opening face is
set to 1 m or more and less than 2 rn, by setting the distance (X - b) to be not more than a
distance of 3 t i e s the flow rate (a distance over which the uniform air flow blown out
10 from the opening face 3 1 collides with the air collision face W within 3 seconds), and
when the width of the opening face is set to 0.2 rn or more and less than 1 m, by setting
the distance (X - b) to be not more than a distance of 2 times the flow rate (a distance
over which the uniform air flow blown out from the opening face 3 1 collides with the air
collision face W within 2 seconds).
15 [OM91 (Examples 20 and 2 1 and Reference Examples 10 and 1 1)
As depicted in FIG. 16, us* a local air cleaning apparatus 1 (nine push hoods 2a
consisting of longitdid three pieces x transversal three pi-, each having a width of
1050 mm and a height of 850 mm) having a bent portion W1 bent toward the side having
the guide 3 (the push hood 2) at side portions of the air collision face W, cleanliness was
20 m e a s d , as depicted in FIG. 17, for cases in which the length b of the guide 3 was 12 m
and the flow rate of a cleaned uniform air flow was 0.5 mls (Example 20 and Reference
Example 10) and 0.2 mls (Example 2 1 and Reference Example 1 1) and for cases in
which the distance (X - b) between the opening face 31 of the guide 3 and the air
collision face W was changed. The cleanliness was obtained by measwing the number
25 of dust particles (piecedCF) having a particle size of 0.3 pm using LASAIR-II
manufactured by PMS Inc. In addition, as in Examples 2 to 10, the cleanliness was
measured at seven pints as respective measurement points A to G in the opening face 3 1,
at a position of 1 5 cm apart from the air collision face W toward the side having the
opening face 3 1, and in the center between the opening face 3 1 and the air collision face
W, respectively, in FIG. 14. The results are given in Tables 1 1 to 14.
[0070] (Example 20)
5 Table 11
1m711 (Reference Example 10)
Table 12
~ 7 2 1 (Example 2 1 )
Table 13
[0073] (Reference Example 1 1 )
Table 14
1m741 As indicated in Example 1 1, Reference Example 1, Example 20, and
Reference Example 10, it was able to be confmned that by having the bent portion W1
5 bent toward the side having the guide 3 (push hood 2) at the side portions of the air
collision face W, the distance between the opening face 3 1 and the air collision face W
that can be cleaned increased to h m 1.5 to 2 m, as well as the shortest distance c
between the end portion of the opening face 3 1 and the bent portion W 1 increased to 1.93
m. In addition, as depicted in Example i 3, Reference Example 3, Example 2 1, and
10 Reference Example 1 1, it was able to be confirmed that, by having the knt portion W 1
bent toward the side thereof having the guide 3 at the side portions of the air collision
face W, the distance between the opening face 3 1 and the air collision face W that can be
cleaned increased to from 0.8 to 1.2 m, as well as the shortest distance c between the end
portion of the opening face 3 1 and the bent portion W 1 increased to 1.16 m. Thus, it
15 was confmed that, due to the arrangement of the bent portion W 1 bent toward the side
having the guide 3 at the side portions of the air collision face W, there can be provided a
local air cleaning apparatus 1 having a simple structure and a larger clean air space can be
formed.
w751 Accordingly, the local air cleaning apparatus 1 using the air collision hce W
20 having the knt portion W1 (the nine gush h d s 2a (the width of the opening face 3 1 :
2650 mm)) was confumed to be able to have a high cleanliness of 300 piWCF or less
by setting the distance (X - b) between the opening face 3 1 of the guide 3 and the air
collision face W to be not more than a distance of 6 times the flow rate (a distance over
which a uniform air flow blown out from the opening face 3 1 collides with the air
collision face W within 6 seconds).
5 [0076] In addition, it was confumed that, with the local air cleaning apparatus 1
using the air collision face W having the bent portion W 1, a high cleanliness of 300
piecedCF or less can be obtained, when the number of the push hods 2a is four (the
width of the opening face 3 1 : 1700 rnrn), by setting the distance (X - b) to to not more
than a distance of 5 times the flow rate (a distance over which the uniform air flow blown
10 out from the opening face 3 1 collides with the air collision fiw W within 5 seconds), and
when the number of the push hoods 2a is one (the width of the opening face 3 1 : 850 rnm),
by setting the distance (X - b) to be not more than a distance of 3 times the flow rate (a
distance over which the uniform air flow blown out h m the opening face 3 1 collide
with the air collision face W within 3 seconds).
15 [0077] The present application is based on Japanese Patent Application No.
20 1 1 - 1 663 16 filed on July 29,20 1 1, Japanese Patent Application No. 20 1 1 - 1 96726 filed
on September 9,201 1, and Japanese Patent Application No. 201 1 -222785 filed on
October 7,201 1, the entire specifications, claims, and drawings of which are incorporated
herein by refmnce.
20 Industrial Applicability
[0078] The present invention is useful for air cleaning in a local work space.
Reference Signs List
[0079] 1 Local air cleaning apparatus
2 a pushhood
25 3 Guide
21 Housing
22 Air flow suction face
Air blowout face (Air flow opening face)
Air blowing mechanism
Higher performance filter
Rectification mechanism
Pre-filter
Opening face
Width of opening face
Air collision face