LOCAL AIR CLEANER
5 'Technical Field
[OOOl] The present disclosure relates to a local air cleaning apparatus.
Rackgroulld Art
[0002] Conventionally, a clean bench is often used as an apparatus for improving
air cleanliness of a local work space. In a typical clean bench, on only a front side of a
10 working table is provided an opening for work, and sides thereof other than the front side
form an enclosure in order to maintain cleanliness. In such a clean bench, a clean air
blowing outlet is arranged within the enclosure, and a worker puts his or her hands
therein fiom the front opening for work and then perfoms the work.
[0003] However, the opening for work in the clean bench is 11al-1-ow. Accordingly,
15 there is a problem in tenns of workability when workers perfo1.m assembly work of a
precision instrument or the like. I11 addition, as in a production line, when work
involves transfer of mailufactured products or nlanufactured compollellts, procedures
such as arranging the entire line in the clean room have been taken. E-Iowever, this leads
to a problem with large-scale equipment.
20 [0004] 'rllus, a local air cleaning apparatus has been proposed in which air flow
opening faces of a pair of push 1.1oods that can blow out a unifonn flow of cleaned air are
arranged opposite to each other to cause air flows fiom the each air flow opening face to
collide with each other, tl~crebyb eing able to make a region between the pair of push
hoods a clean air space I~avinga higher level of cleailliness than in other regio~ls( Patent
25 Literature 1).
Citation List
Patent Literature
[0005] Patent Literature 1 : Unexamined Japanese Patent Application Kokai
Publication No. 2008-275266
Summary of Invention
Technical Problem
5 [0006] Meanwhile, although a local air cleaning apparatus can make a work space a
clean air space in a sho1-t time, depending on the worker, he or she may desire to maintain
a11 inside of the work space constantly at a high level of cleanliness even during a time
when he or she is off work. I11 such a case, when the worker is not working in the work
space, power consunlption of the local air cleaning apparatus is desired to be reduced as
10 much as possible.
[0007] The present disclosure has been accomplished in view of the above
circumstances. It is an objective of the present disclosure to provide a local air cleaning
apparatus that can reduce power consumption while maintaining a clean air space at a
high level of clea~lliness.
15 Solution to Problem
[0008] In order to achieve the above objective, a local air cleaning apparatus
according to a first aspect of the present disclosure includes:
a push hood including a11 air flow opening face that blows out a cleaned unifonn
air flow; and
20 a guide provided on a side of the push hood having the air Row opening face and
extending li.01~t1h e side thereof having the air flow opening face to a downstream side of
the unifor~na ir ilow to forn~a1 1 opening face at an end poi-tion of the downstream side,
in which the push hood is arranged such that the cleaned uniform air flow blown
out fiom the air llow opening fjcc passes through inside the guide and then collides with
25 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 opposite to the air collision face to form an
open region between the opening face of the guide and the air collisiol~fa ce; and
the cleaned uniform air flow blown out from the air flow opening face collides with the
air collision face to flow outside the open region, so as to cause cleanliness to be higher
inside the guide and inside the open region than other regions, wherein
the local cleaning apparatus includes at least one of a device for measuring
5 pressures inside the guide and inside the push hood, a device for measuring the
cleanli~lessin side the guide or of the open region, and a device for measuring a gap area
between the guide and the air collision face; and
to ensure the cleanliness from a result of the measurement, the local cleaning
apparatus controls such that a flow velocity of the cleaned unifosm air flow blown out
10 from the air flow opening face can be decelerated or accelerated.
[0009] A local air cleaning apparatus according to a second aspect of the present
disclosure includes:
a pair of push hoods each including an air flow opening face that blows out a
cleaned uniform air flow; and
15 a guide provided on a side of each of the pair of push hoods having the air flow
opening face side and extending from the side of each of the pair thereof having the air
flow opening face to a downstream side of the uniform air flow to foirn an opening face
at an end postion of the downstream side,
in which the opening faces of the pair of guides are spaced apart from and opposite
20 to each other to fonn an open region between the opening faces of the each guide; and
the cleaned uniform air flows blown out from the each air flow opening face collide with
each other inside the open region to flow outside the open region, so as to cause
cleanliness to be higher inside the guides and inside the open region than other regioils,
wl~crein
25 the local air cleailing apparatus incl~tdesa t least one of a device for measuring
pressures insidc the guides and the push hoods, a device for measuring thc cleanliness
inside the guides or of the open region, and a device for measuring a gap area between
the opening faces of tlie guides; and
to ensure the cleanliness fiom a result of tlie measurement, the local air cleaning
apparatus controls such that a flow velocity of the cleaned uniform air flows blown out
from the air flow opening faces can be decelerated or accelerated.
5 [OOlO] A local air cleaning apparatus according to a third aspect of the present
disclosure includes:
a pair of push hoods each including an air flow opening face that blows out a
cleaned uniform air flow; and
a guide provided on a side of one of the pair of push hoods having the air flow
10 opening face and extending from the side of one of the pair thereof having the air flow
opening face to a downstream side of the unifornl air flow to fo~man opening face at an
end portion of the downstream side,
in which the opening face of the guide is spaced apai-t fiom and opposite to the air
flow opening face of the push hood not provided with the guide to form an open region
15 between the opening face of the guide and the air flow opening face of the push hood not
provided with the guide; and
the cleaned unifolm air flows blown out from the each air flow opening face
collide with each other inside the open region to flown outside the open region, so as to
cause cleanliness to be higher inside the guide and inside the open region than other
20 regions, wherein
the local air cleaning apparatus includes at least one of a device for measuring
pressures inside the guidc and inside the push hoods, a device for measuring the
cleanliness inside the guide or of the open region, and a device for lneasuring a gap area
between the opening face of the guidc and the pus11 hood not provided with the guide;
25 and
to ensure the cleanliness fioin a result of the measurement, the local air cleaning
apparatus controls such that a flow velocity of the cleaned uniform air flows blown out
from the air flow opening faces can be decelerated or accelerated.
[OOl 11 The guide may include a moving portion capable of changing a guide length.
In this case, a distance between the opening iBce of the guide and the air collision face
may be shortened by moving the moving portion to increase the guide length.
5 Advantageous Effects of Invention
[00 1 21 The present disclosure allows power consumption to be reduced while
maintaining a clean air space at a high level of cleanliness.
Brief Description of Drawings
[00 1 31 FIG. 1 is a diagram depicting a local air cleaning apparatus according to an
10 embodiment of the present disclosure;
FIG. 2 is a diagram depicting a stmcture of a push food;
FIG. 3 is a diagram depicting a structure of a guide;
FIG. 4 is a diagram depicting a structure of a controller;
FIG. 5 is a diagram depicting a relationship between wind velocity of air flow
15 blown out fsom an air flow opening face and gap area;
FIG. 6 is a diagram for illustratillg a flow of air in a normal mode;
FIG. 7 is a diagram for illustrating a flow of air in an energy-saving mode;
FIG. 8 is a diagram depicting another example of the local air cleaning apparatus;
FIG. 9 is a diagram depicting another exalnple of the local air cleaning apparatus;
FIG. 10 is a diagram depicting a local air cleaning apparatus used in an Example;
and
FIG. 11 is a diagram depicting results of energy consumption and cleal~liness
inside the guide in cases where distance a (gap area) and flow velocity have been
changed.
25 Description of Embodiments
[00 141 I-Iereinafter, a description will be given of a local air cleaning apparatus
according to the present disclosure, with reference to the drawings. FIG. 1 is a diagram
depicting an example of a local air cleaning apparatus according to an embodiment of the
present disclosure.
[00 1 51 As depicted in FIG. 1, a local air cleaning apparatus 1 of the present
disclosure includes a push hood 2 arranged so as to face an air collision face W such as a
5 wall or a partition, a guide 3 provided on the push hood 2, and a controller I00 that
controls each section of the apparatus.
[00 161 The push hood 2 can be any push hood as long as the push hood has a
mechanism that blows out a cleaned uniform air flow. For the push hood 2, therc can be
employed a structure in which a cleaning filter is incorporated in a basic push hood
10 stlucture conventionally used in push-pull ventilators.
[00 1 71 The terms uniform air flow and uniform flow used herein have the same
meaning as unifonn flow described in "Industrial Ventilation" by Taro I-Iayashi (1 982,
published by the Society of ~eatingA, ir-Conditioning and Sanitary Engineers of Japan,)
and refer to a flow having a breeze velocity that is uniformly continuous and causes IIO
15 large whirling portion. However, the present disclosure does not intend to provide an
air blowout apparatus whose air flow velocity and velocity distribution is strictly
specified. Regarding the uniform air flow, for example, variation in velocity
distribution in a state where there are no obstacles is preferably within ?50%, and
ful-thermore within ?30%, with respect to an average value of the variation.
20 [0018] The push hood 2 is arranged such that the air flow opening face 23 thereof
opposes the air collisio~fa~c e W such as a wall. Herein, a meaning of the phrase, "the
air flow opening facc 23 thereof opposes the air collision face W" includes not only a
state where the air flow opening face 23 of the push food 2 and the air collision face W
oppose in parallel to each other, but also, for example, a state where the air flow opening
25 face 23 of the push food 2 and the air collision face W are slightly illclined horn each
other. As for the inclination between the air flow opening fjce 23 of the p~is11h ood 2
and tl~eai r collision face W, an angle formed by the air flow opening ijce 23 and the air
collision face W is preferably within a range of about 30 degrees.
[00 1 91 In the push hood 2 of the present embodiment, each of nine (longitudinal
three pieces x transversal thee pieces) push hoods is connected to each other by a
connection tool such that the air flow opening faces thereof are oriented in the same
5 direction and short sides and long sides, respectively, of the push hoods are arranged
adjacent to each other. FIG. 2 depicts a stl-ucture of one pus11 hood 2a. In addition,
structures ofthe other connected push lloods 2 are also basically the same as the structure
thereof.
[0020] As depicted in FIG. 2, a housing 2 1 of the push hood 2a is foimed into a
10 substailtially rectallgular parallelepiped shape, and an air flow suctioi~fa ce 22 is folmed
on one surface of the housing 2 1. The air flow suctioil face 22 comprises, for example,
a face where a plurality of holes are formed on an entire past of the one surface of the
housing 21. The air flow suction face 22 takes in outside air or room air that is ambient
air outside the push hood 2a tlxough the holes. In addition, an air blowout face (an air
15 flow opening face) 23 is fonned on an other surface of the housing 2 1 opposing the air
flow suction face 22. Tlle air flow opening face 23 comprises, for example, a face
where a plurality of holes are folmed on an entire past of the one surface of the housing
21. In the air flow opening face 23, a uniform air flow of clean air formed in the push
hood 2a is blown out of the push hood 2a througl~th e holes. A size of the air flow
20 opening face 23 of the push hood 2a is not pa~-ticularlyli mited, but is, for example, 1050
x 850 Inm.
[002 1 ] 111 the housing 21 are arranged an air blowing mechanisn124, a high
performa~lcef ilter 25, and a rectification n~ecl~anis2m6 .
The air blowing mechanism 24 is arranged on the side of the housing 21 where the
25 air flow suction face 22 is located. The air blowing mechanism 24 col~~prisae sfa n 125
or the like for blowing out air. The air blowing mechanis~n2 4 takes in outside air or
rooin air that is ambient air of the push hood 2a fion~th e air flow suction face 22 and
blows out an air flow f'som the air flow opening face 23. As will be described later, the
fan 125 is connected to the controller 100 to be able to change a flow velocity of the air
flow blown out fi-om the air flow opening face 23.
100221 'I'he high perfoimance filter 25 is arranged between the air blowing
5 mechanism 24 and the rectification mechanism 26. The high performance filter 24
comprises a high perfo~nlancef ilter in accorda~lcew ith the level of cleaning, such as a
I-IEPA filter (High Efficiency Particulate Air Filter) or an ULPA filter (Ultra Low
Penetration Air Filter) for filtrating ambient air taken in. The high performance filter 25
cleans tlle ambient air taken in by the air blowing mechanism 24 to a desired cleanliness
10 level. The clean air cleaned to the desired cleanliness level by the high perfortnance
filter 25 is sent to the rectification mechanism 26 by the air blowing mechanism 24.
100231 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 and formed with a punching plate, a net member, or the like.
15 The rectification mechanism 26 coi-sects (rectifies) blown air sent from the higher
perfolmance filter 25 and having an amount of aeration biased with respect to an entire
part of the air flow opening face 23 into a uniformized air flow (a uniform air flow)
l~avinga n amount of aeration unbiased with respect to the entire part of the air flow
opening face 23. The u~liforna~ir flow obtained by the rectification is blown out by the
20 air blowing mechanism 24 from the entire pai-t of the air flow opening face 23 to the
outside of tlle push hood 2.
100241 In addition. as depicted in FIG. 2, the pus11 hood 2a is preferably provided
with a pre-filter 27 arranged between tl~cai r flow suctioil face 22 and the air blowing
mechanism 24 in the 11ousing 2 1. An example of the pre-filter 27 may be a mediuiu
25 perfortnancc filtcs. The an-angement of tl~epr e-filter 27 between the air flow suction
face 22 and the air blowing n~cchanism2 4 allows removal of relatively large dust
particles contained in the ambient air sucked into the housing 21 through the air flow
suction face 22. In this way, the dust pai-ticles can be removed in multiple stages
according to the size of the dust particles contained in the ambient air. Accordingly, the
high performance filter 25, which tends to cause clogging or the like, can maintain
perfoimance thereof for a long period.
5 [0025] In the push hood 2a thus configured, the ambient air taken in by the air
blowing mechanism 24 is cleaned to a desired cleanliness level by the pre-filter 27 and
the high performa~lcefi lter 25. Then, the clean air subjected to the cleaning is rectified
into a unifonn air flow by the rectification mechanism 26. The uniform air flow thus
cleaned is blown to outside from the entire part of the air flow opening face 23 in a
10 direction substantially perpentdicular to the air flow opening face 23 of the push hood 2a.
[0026] One end of the guide 3 is provided on a 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 to a downstream side of the
uniform air flow blown out from the air flow opening face 23 to cover an outer peripheral
15 outline portion of the air flow opening face 23. For example, when the air flow opening
face 23 has a quadra~lgulars hape, the guide 3 is foimed to be extended in such a manner
as to have a U-letter cross-sectional shape. With an open side of the U-letter shape and
a floor surface, the guide 3 is brought into a state of enclosing the outer peripheral outline
postion in a blowout direction of the uniform air flow and surrounding, like a tunnel, a
20 periphery of an air flow in parallel to a stream of the uniform air flow blown out
therefi-om.
[0027] The guide 3 can be formed using an arbitraiy material as long as an air flow
blown out from the opening face 3 1 thereof can maintain the state of the cleaned uniform
air flow blown out from the air flow opening face 23. In addition, the guide 3 does not
25 necessarily have to completely cover an entire periphery of the uniform air flow as long
as the state of the cleaned uniform air flow blown out from the air flow opcning face 23
can be maintained. For example, the guide 3 may have a hole or a slit formed in a part
thereof.
[OOZS] Preferably, the opening face 3 1 is formed so as to have substantially the
same shape as the air flow opening face 23. The reason for that is that forming the
opening face 3 1 and the air flow opening face 23 in substantially the same shape allows
5 the state of the uniform air flow blown out fi-om the air flow opening face 23 to be easily
maintained on the opening face 3 1.
[0029] A length b of the guide 3 is made to be a length that allows a space having a
desired size to be formed between the air flow opening face 23 and the air collision face
W and allows the opening face 3 1 and the air collision face W to be ai~angeds o as to be
10 able to face each other in a state of being spaced apai-t from each other by a
predetermined distance a. Then, the guide 3 is arranged such that the opening face 3 1
and the air collision face W face each other in the state of being spaced apart fi-om each
other by the predetermined distance a therebetween. Thus, since the opening face 3 1 is
arranged so as to oppose the air collision face W in the state of being spaced apart
15 therefrom, an open region is formed between the opening face 3 1 and the air collision
face W. In this state, the uniform air flow blown out from the air flow opening face 23
of the push hood 2 (the opening face 3 1) collides with the air collision face W to change a
flowing direction thereof. For example, when the opening face 3 1 is opposed in parallel
to a wall, the unifom air flow collides with the air collision face W and then exhibits a
20 behavior of changing the direction of the flow substantially perpendicularly. Then, the
unifoim air flow having collided with the air collision face W and having changed the
flow direction thereof is discharged from the open region between the opening face 3 1
and the air collision face W to outside a space between the air flow opening face 23 and
the air collision face W. As a result, a clean space can be obtained in the region between
25 the air flow opening face 23 and the air collision face W.
[0030] In addition, the local air cleaning apparatus 1 of the present disclosure is
provided with a distance adjustment mechanism that can adjust the distance a between
the opening face 3 1 and the air collision face W. In the present embodiment, as
depicted in FIG. 3, the guide 3 is provided with a moving portion 32 that is foimed so as
to cover a side of the guide 3 having the opening face 3 1 and is capable of changing the
length b of the guide 3. As will be described later, the moving portion 32 is connected
5 to the moving mechanism 127, and the moving mechanism moves the moving poi-tion 32
to change the length b of the guide 3, thereby being able to adjust the distance a between
the opening face 3 1 and the air collision face W.
1003 11 In addition, the local air cleaning apparatus 1 of the present disclosure
includes at least one of a device for measuring pressures inside the guide 3 and inside the
10 push hood 2, a device for measuring cleanliness inside the guide 3 or the open region, and
a device for measuring a gap area between the guide 3 and the air collision face W.
Then, from the measusement result, the local air cleaning apparatus 1 controls in order to
ensure cleanliness such that a flow velocity of the cleaned uniform air flow blown out
from the air flow opening face 23 can be decelerated or accelerated.
15 [0032] Examples of the device for measuring pressures inside the guide 3 and
inside the push hood 2 include a pressure gauge 123, which will be described later.
Examples of the device for measuring the cleanliness of the open region include a particle
counter capable of measuring a number of dust particles. Examples of the device for
measuring the gap area between the guide 3 and the air collision face W iilclude a
20 distance sensor.
[0033] Herein, the gap area refers to any one of the following areas:
(1) An area of three faces open between the opening face 3 1 of the guide 3 and the
air collision face W (an area of four faces if there is no floor);
(2) An area of thee faces open between the opening face 3 1 of the guide 3 and the
25 push hold 2 not provided with the guide 3 (ail area of four faces if there is no floor); and
(3) An area of three faces open between openi~lgfa ces 3 1 of guides 3(an area of
four faces if there is no floor).
Examples of a method for measuring such a gap area includc a method of simply
calculating from the distance sensor and lengths of sides of the guide 3 and a method of
calculating fiom a blown-out air velocity in the gap and a volume of air blown out from
the push hood 2.
5 [0034] The controller 100 controls each device section of the local air cleaning
apparatus 1. FIG. 4 depicts a structure of the controller 100. As depicted in FIG. 4, an
operation panel 12 1, the pressure gauge 123, the fan 125, the moving mechanism 127,
and the like are connected to the controller 100.
[003 51 The operation panel 12 1 includes a display screen and operation buttons to
10 send an operation instiuction of an operator to the controller 100. In addition, the
operation panel 12 1 displays various kinds of information fiom the controller 100 on the
display screen.
[0036] The pressure gauge 123 is incoiyorated, h r example, in the push hood 2,
and one of measurement ports thereof is arranged inside the guide 3 and the other one
15 thereof is ai-sanged inside the push hood 2. The pressure gauge 123 measures an inner
pressure inside the guide 3 and an inner pressure inside the push hood 2 to notify a
pressure difference therebetween to the controller 1 00.
100371 The fan 125 controls a flow velocity of an air flow blown out fiom the air
flow opening face 23 to have an amount instructed by the controller 100.
20 [0038] The moving mechanism 127 is connected to the moving portion 32 to move
the moving portion 32 so as to set the length b of the guide 3 to a length il~structedb y the
controller 100. In addition, the moving mechanism 127 includes a sensor or the like for
measurirlg a position of the moving poi-tion 32 to notify the position of the moving
portion 32 (the length b of the guide 3) to the controller 100.
25 100391 The controller 100 comprises a ROM (read only mcmory) 1 1 1. a RAM
(random access memory) 1 12, an 110 post (input/output po1-t) 1 13, a CI'U (central
processing unit) 1 14, and a bus 1 15 for connecting these elements to each other.
[0040] The ROM 11 1 comprises an EEPROM (electrically erasable programmable
read only memory), a flash memory, a hard disk, or the like, and is a storage medium for
storing an operation program of the CPU 1 14 and the like. The RAM 1 12 hnctions as a
work area of the CPU 1 14 or the like.
5 [0041] The 110 port 1 13 is conncctcd to the operation panel 12 1, the pressure gauge
123, the fall 125, the movii~gm echanism 127, and the like to control inputloutput of data
and signals.
[0042] The CPU 1 14 forms a core of the controller I00 and executes a control
program stored in the ROM 1 1 I to coiltrol operation of the local air cleaning apparatus 1
10 according to an instruction fiom the operation panel 12 1. In other words, the CPU 1 14
causes the pressure gauge 123, the fan 125, and the like to specifL pressure, air volume,
gap air velocity, contaminant concentration, and the like inside the guide 3, and based on
the data, outputs a control signal or the like to the fan 125 and the like to control the
operation of the local air cleaning apparatus 1.
15 [0043] The bus 1 15 collveys il~folmatiobl~et ween the respective sections.
[0044] I11 addition, the controller 100 stores a model indicating a relationship
between air velocity (flow velocity) of blowout fiom the air flow opening face 23 and
gap area, as depicted in FIG. 5. This model is a model that indicates a relatioilship
between gap area and flow velocity of a cleaned uniform air flow blown out from the air
20 flow opening face 23 ill a state where cleanliness is ensured, and which is a model that
allows calculation of a flow velocity of the air flow blown out from the air flow opening
face 23 that call ensure cleanliness when the gap area is changed.
[0045] Next, a description will be given of operation of the local air cleaning
apparatus 1 thus configured. 111 the prescllt embodiment, the operation of the local air
25 cleaning apparatus 1 will be illustrated by describing a change fio~na state where there is
a worker working in a work space (normal mode) to a state where there is no worker
working in the work space (energy-saving mode).
[0046] First will be described a case of starting the local air cleaning appasatus 1 in
the nonnal mode. For example, when a worker operates the operation panel 12 1 to
select stal-t (normal mode start) of the local air cleaning apparatus 1, the CPU 1 14
controls the fan 125 (drives the fan 125 at a predetermined number of rotations) to cause
5 the fa11 125 to suck ambient air near the air flow suction face 22. The ambient air thus
sucked is cleaned by the pre-filter 27 and the high performance filter 25 to obtain clean
air having a desired cleanliness level. Then, the clean air obtained by the cleaning is
rectified into a ulliform air flow by the rectification mechanism 26, and the cleaned
unifoim air flow is blow11 out to the guide 3 from the entire part of the air flow opening
10 face23.
[0047] The cleaned uniform air flow blown out to the guide 3 passes through the
guide 3 to be blown out from the opening face 3 1 while maintaining the state of the
uniform air flow, and collides with the air collision face W. The air flow having
collided flows out from the open region between the opening face 3 1 and the air collision
15 face W to outside the regioil between the air flow opening face 23 and the air collision
face W (outside the local air cleaning apparatus I), as depicted in FIG. 6. 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 face W)
can be made to be a region having a higher level of cleanliness than in a region outside
20 the local air cleaning apparatus 1.
100481 The lengtll b of the guide 3 (the position of the moving portion 32) in the
normal mode (nonnal position) is notified to the CPU 114 by the moving mechanism
127.
[0049] Next will be described a case of switching the local air cleaning apparatus 1
25 fiom the 11or111al mode to the energy-saving mode. For example, when an operator
operates the operation panel 12 1 to select switching of the local air cleaniilg apparatus 1
(switching to the energy-saving mode), the CPU 1 14 controls the moving mechanism 127
to move the position of the moving portion 32 in the direction of the air collision face W
such that the positioil of the moving portion 32 is changed fiom the normal position to a
position thereof in the energy-saving mode (energy-saving position), thereby reducing the
gap area.
5 [0050] Next, the CPU 114 causes the distance sensor to calculate the gap area in the
state where the moving portion 32 is located in the energy-saving position, and using the
model depicted in FIG. 5, calculates a flow velocity of blowout from the air flow opening
face 23 that can ensure cleanliness. Then, the CPU 114 controls the flow velocity of
blowout from the air flow opening face 23 to be a calculated flow velocity. I11 the state
10 where the flow velocity of blowout from the air flow opening face 23 is controlled as
described above, a flow velocity of air discharged from the open region between the
opening face 3 1 and the air collision face W is substantially constant in the normal mode
and the energy-saving mode, as depicted in FIG. 7. Thus, even in the energy-saving
mode, the region between the air flow opening face 23 and the air collision face W can be
15 maintained at a higher level of cleanliness than the region outside the local air cleaning
apparatus 1. Additionally, lengths of arrows of FIGS. 6 and 7 represent a flow velocity
of air. Furthermore, since the flow velocity of the air discharged from the open region
between the opening face 3 1 and the air collision face W is substantially constant in the
normal mode and the energy-saving mode, contaminants such as dust particles hardly
20 enter from the outside into the guide 3. Accordingly, the region between the air flow
opening face 23 and the air collision face W can be maintained at a higher level of
cleanliness than the region outside the local air cleaning apparatus 1.
[OOS 1 ] Examples of means for confirn~ingth at a high level of cleanliiless is being
maintained (which means being equal to the cleanliness of the normal mode) include
25 measurement of a number of dust particles by a particle counter, maintaining the inner
pressure at a constant value, and maintaining the blown-out air velocity fiorn the gap.
For example, when a numerical value of the particle counter indicates a high level value,
the fan 125 is controlled so that the flow velocity fiom the push hood 2 increases. On
the other hand, when the numerical value of the particle counter indicates a low level
value, the fan 125 controls so that the flow velocity fiom the push hood 2 reduces.
Additionally, when the blown-out air velocity from the gap reduces fiom a predetermined
5 value, the fan 125 is controlled so that the flow velocity fiom the push hood 2 increases.
On the other hand, when the blown-out air velocity from the gap increases froin the
predetermined value, the fan 125 is controlled so that the flow velocity from the pus11
hood 2 reduces.
[0052] In this way, when a sufficient level of cleanliness is obtained, energy-saving
10 operation can be performed by reducing the flow velocity. In the energy-saving mode,
the number of rotation of the fan 125 is reduced as compared to the noimal mode to
reduce the flow velocity of the uniform air flow blown out from the air flow opening face
23, thus allowing reduction in power consumption of the local air cleaning apparatus 1.
[0053] Additionally, in the local air cleaning apparatus 1 of the present embodiment,
15 when a hole is foimed in the guide 3 and thereby the pressure inside the guide 3 is
reduced, the number of rotations of the fan 125 is increased to raise the inner pressure of
the guide 3, thereby maintaining cleanliness in the region between the air flow opening
face 23 and the air collision face W. Furthermore, wl~enp ower supply is lowered and
thereby the air velocity of the cleaned uniform air flow blown out fiom the air flow
20 opening face 23 is decelerated, the pressure inside the guide 3 is reduced. Accordingly,
the number of rotations of the fan 125 is increased to raise the inner pressure of the guide
3, thereby maintaining cleanliness in the region between the air flow opening face 23 and
the air collision face W.
COO541 As described I.~ereinabovei,n the local air cleaning apparatus 1 of the present
25 embodiment, the position ofthe moving postion 32 is moved li-om the nornlal position to
the energy-saving positio~tlo thereby reduce the gap area and control the flow velocity of
blowout from the air flow opening face 23 to be a flow velocity that can ensure
cleanliness. Thus, power consumption can be reduced while maintaining the region
between the air flow opening face 23 and the air collision face W at a high level of
cleanliness.
[0055] In addition, the present disclosure is not li~nitedto the above embodiment,
5 and various modifications and applications can be made. Hereinafter, a description will
be given of other embodiments applicable to the present disclosure.
[0056] The above embodiment has described the present disclosure by
exemplifying the case in wllich the gap area is reduced by moving the position of the
moviilg portion 32. However, it is enough for the local air cleaning apparatus 1 of the
10 present disclosure to have a structure capable of changing the gap area. For example,
the gap area may be changed by providing a moving mechanism that allows the push
hood 2 to be advancedlretracted in a direction of the air collision face W at a lower end of
the push hood 2. Alternatively, the gap area may be changed by fonning the guide 3
into an accordion shape. Furthermore, covering with a curtain or the like may be used
15 as an alternative to the air collision face W. Additionally, the gap area may be changed
by adding an air collision face W.
[0057] The above embodiment has described the present disclosure by
exemplifying the case where the gap area is reduced and the flow velocity of blowout
from the air flow opening face 23 is controlled to be a flow velocity that can ensure
20 cleanliness. However, for example, the distance a between the opening face 3 1 and the
air collision face W may bc shortened and the flow velocity of blowout fi-om the air flow
opening kce 23 may be controlled so that the pressure inside the guide 3 becomes
constant, i.e, the flow velocity of blowout from the air flow opening face 23 may be
controlled to be a flow velocity that can ensure cleanliness.
25 [005S] 'The above enlbodirnent has described the pscsent disclosureexemplified by
the case where a worker operates the operation panel 121 to switch the local air cleaning
apparatus 1 to the energy-saving mode. However, for example, the local air cleaning
apparatus 1 may be switched to the energy-saving mode by manually inoving the air
collision face W. In addition, with a timer or the like, the local air cleaning apparatus 1
may be automatically switched to the energy-saving mode at night.
[0059] The above embodiment has described the present disclosure by
5 exemplifying the case where a worker operates the operation panel 12 1 to switch the
local air cleaning apparatus 1 to the energy-saving mode. However, for example,
instead of increasing the flow velocity of the unifor~na ir flow when a count of the
particle counter increases, the air collision face W may be autonlatically moved toward
the guide 3, so as to maintain cleanliness. Furthermore, a pressure gauge can be used
10 instead of the particle counter. 111 this way, cleanliness may be maintained not only by
increasing or reducing the flow velocity of the uniform air flow but also by increasing or
reducing the inner pressure, increasing or reducing the gap area, or increasing or reducing
the flow velocity of air blown out from the gap.
[0060] While the above embodiment has described the present disclosure by
15 exemplifying the case where the air collision face W is flat like a wall or a partition, the
air collision face W is not limited thereto. For example, preferably, the air collision face
W has bent portions W I bent toward the guide 3 (the push hood 2) at end portions thereof
that are close to positions opposing 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. 8. Alternatively,
20 the air collision face W may have bent portions W 1 where all of an upper portion, a lower
portion, and the side portions thereof are bent toward the side of the apparatus 1 having
the guide 3. In addition, the bent portions W 1 may have rounded corners (have
roundness on comers) so as to have a gently curved surface. Providing the bent portions
W 1 at the air collision face W, as described above, facilitates the preventio~lo f inflow of
25 air fiom outside the open region fornled between the guide 3 and the air collision fjce W
(outside the local air cleaning apparatus 1).
[006 11 The above embodiment has described the present disclosure by
exemplieing the case of the local air cleaning apparatus 1 in which the push hood 2 and
the air collision face W are at-sanged to oppose each other. However, for example, as
depicted in FIG. 9, a local air cleaning apparatus 1 may be used in which a pair of push
hoods 2 are arranged to oppose each other and each of the push hoods 2 is provided with
5 a guide 3. Alternatively, a local air cleaning apparatus 1 may be used in which a pair of
push hoods 2 are arranged to oppose each other and one of the push hoods 2 is provided
with a guide 3.
[0062] The above embodimellt has described the present disclosure by
exemplibing the case of the push hood 2 in which each of the nine (longitudinal three
10 pieces x transversal three pieces) push hoods 2a is connected to each other by a
connection tool. However, the number of the push hoods 2a forming the push hood 2
may be not less than 10 or not more than 8. For example, the push hood 2 may be
fo~medby connecting each of four (longitudinal two pieces x transversal two pieces)
push hoods 2a to each other by a connecting tool. When connecting the push hoods 2a
15 as in these examples, the push hoods 2a are arranged such that the air flow opening faces
of the push hoods 2a are oriented in the same direction and short sides of the push hoods
2a and long sides thereof, respectively, are adjacent to each other. Alternatively, the
push hood 2 may comprise a single push hood 2a.
EXAMP1,ES
20 [0063] Hereinafter, specific Examples of the present disclosure will be provided to
firrther describe the present disclosure in detail. t
[0064] Using a local air cleaning apparatus 1 depicted in FIG. 10, power
consun~ptiona nd cleanliness inside the guide 3 were measured in a case where distance a
between the opening face 3 1 and the air collision face W and flow velocity of blowout
25 fiom the push hood 2 were changed in a state where pressure inside the guide 3 was
maintained at 5 Pa. Additionally, the push hood 2 was one comprising four push hoods
2a (longitudinal two pieces x transversal two pieces) each having a width of 1050 mm
and a height of 850 rnrn connected by arranging such that the air flow opening faces of
the push hoods 2a were oriented in the same direction and short sides and long sides,
respectively, of the push hoods 2a were adjacent to each other. The opening face 3 1 has
a width of 21 00 mxn and a height of 1700 mm. Additionally, a case of a distance a of
5 1000 mm (gap area: 55000 cm2) cot~espondsto the case where the local air cleaning
apparatus 1 is in the above-mentioned no~maml ode, and cases of distances a of 9 mm
(gap area: 495 cm2), 1 5 mm (gap area: 825 cm2), and 22 mm (gap area: 1 2 1 0 cm2)
cowespond to the case where the local air cleaning apparatus 1 is in the above-mentioned
energy-saving mode. The measurement of cleanliness was performed by measuring the
10 number of dust particles (pieces1CF) having a particle size of 0.3 pm using LASAIK-I1
mallufactured by PMS Inc., and specifying IS0 Class from results of the measurement.
FIG. 1 1 depicts the results.
[0065] As depicted in FIG. 1 1, it was confirmed that the cleanliness inside the
guide 3 in tlie nonnal mode (gap area: 55000 cm2) was at a high level of cleanliness, IS0
15 Class 1, and even in the energy-saving mode (gap areas: 495 cm2, 825 cm2, and 121 0
cm2), the cleanliness inside the guide 3 was at the high level of cleanliness, IS0 Class 1.
Additionally, in the energy-saving mode, power consumption was confirmed to be able to
be reduced to about 113 of the normal mode. These results showed that power
co~lsumptionc an be reduced while maintaining the clean air space between the air flow
20 opening face 23 and the air collision face W at a high level of cleanliness.
100661 'T'l~efo regoing describes some example embodiments for explanatory
purposes. Although the foregoing discussion has prcsented specific embodimcnts,
persons skilled in the art will rccognize that changes may be made in form and detail
without departing fsom the broader spirit and scope of tlie invention. Accordingly, the
25 specification and drawings are to be regarded in an illustrative rather tlian a restrictive
sense. This detailed description, therefore, is not to be taken in a limiting sense, and tlie
scope of tlie invention is defined only by the included clairns, along wit11 the fill1 range of
cquivaleiits to which such claims are entitled.
[0067] This application is based on Japanese Patent Application No. 2012-268614,
filed on Dec. 7,201 2, the entire contents of which, inclusive of the specification, claims,
and drawings, are hereby incorporated by reference herein.
5 Industrial Applicability
[0068] The present disclosure is useful for cleaning air in local work spaces.
Reference Signs List
[0069]
1 Local air cleaning apparatus
10 2,2a Push hood
3 Guide
21 Housing
22 Air flow suction face
23 Air blowout face (Air flow opening face)
15 24 Air blowing mechanism
25 High performance filter
26 Rectification mechanism
27 Pre-filter
3 1 Opening face
20 32 Moving portion
100 coiltroller
11 1 ROM
112 RAM
113 I10 po1-t
25 114 CI'U
115 Bus
12 1 Operation panel
123 Pressure gauge
125 Fan
127 Moving mechanism
W Air collision face

WE CLAIM:
1. A local air cleaning apparatus comprising:
a push hood including an air flow opening face that blows out a cleaned unifornl
air flow; and
5 a guide provided on a side of the push hood having the air flow opening face and
extending from the side thereof having the air flow opening face to a downstrearn side of
the unifoim air flow to folm an opening face at an end portion of the downstream side,
in which the push hood is arranged such that the cleaned uniform air flow blown
out from the air flow opening face passes through inside the guide and then collides with
10 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 opposite to the air collision 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 from the air flow opening face collides with the
air collision face to flow-outside the open region, so as to cause cleanliness to be higher
15 inside the guide and inside the open region than other regions, wherein
the local air cleaning apparatus comprises at least one of a device for ineasuring
pressures inside the guide and inside the push hood, a device for ineasuring the
cleanliness inside the guide or of the open region, and a device for ineasuring a gap area
between the guide and the air collision face; and
20 to ensure the cleanliness from a result of the measurement, the local air cleaning
apparatus controls such that a flow velocity of the cleaned unifonn air flow blown out
froin the air flow opening face can be decelerated or accelerated.
2. A local air cleaning apparatus comprising:
a pair of push hoods each including an air flow opening face that blows out a
cleaned uniform air flow; and
a guide provided on a side of each of the pair of push hoods having the air llow
opening face side and extending froin the side of each of the pair thereof having the air
flow opening face to a downstream side of the uniforn~a ir flow to form an opening face
at an end portion of the downstream side,
in which the opening faces of the pair of guides are spaced apart fiom and opposite
5 to each other to form an open region between the opening faces of the each guide; and
the cleaned uniform air flows blown out from the each air flow opening face collide with
each other inside the open region to flow outside the open region, so as to cause
cleanliness to be higher inside the guides and inside the open region than other regions,
wherein
10 the local air cleaning apparatus comprises at least one of a device for measuring
pressures inside the guides and the push hoods, a device for measuring the cleallliiless
inside the guides or of the open region, and a device for measuring a gap area between
the opening faces of the guides; and
to ensure the cleanliness fiom a result of the measurement, the local air cleaning
15 apparatus controls such that a flow velocity of the cleaned uniform air flows blown out
from the air flow opening faces can be decelerated or accelerated.
3. A local air cleaning apparatus comprising:
a pair of push hoods each including an air flow opening face that blows out a
20 cleaned uniform air flow; and
a guide provided on a side of one of the pair of push hoods having the air flow
opening face and extcndillg from the side of one of the pair thereofl~avingth e air flow
opening face to a downstream side of the unifolm air flow to form an opening face at an
end portion of the downstream side,
2 5 in which the opening face of the guide is spaccd apart from and opposite to the air
flow opening facc of the push hood not provided with the guidc to form an open region
betweell the opening facc of the guide and the air flow opening face of the push hood not
provided with the guide; and
the cleaned uniform air flows blown out from the each air flow opening face
collide with each other inside the open region to flown outside the open region, so as to
cause cleanliness to be higher inside the guide and inside the open region than other
5 regions, wherein
the local air clealling apparatus comprises at least one of a device for measuring
pressures inside the guide and inside the push hoods, a device for measuring the
cleanliness inside the guide or of the open region, and a device for measuring a gap area
between the opening face of the guide and the push hood not provided with the guide;
10 and
to ellsure the cleanliness fi-om a result of the measureme~ltt,h e local air cleaning
apparatus controls such that a flow velocity of the cleaned uniform air flows blown out
from the air flow opening faces can be decelerated or accelerated.
15 4. The local air cleaning apparatus according to Claim 1, wherein
the guide includes a moving portion capable of changing a guide length, and a distance
between the opening face of the guide and the air collision face is shortened by moving
the moving portion to increase the guide length.