JP2013024550A - Push-pull type ventilator - Google Patents

Abstract

Provided is a push-pull type ventilator that discharges harmful gas on a work space to the outside without diffusing, and is easy to install and move even if there is an exhaust port on the back side of the pull hood.
An upper push hood 3 for supplying a laminar flow 2 and a lower surface 7a of the upper push hood 3 are used as a work space 4, a suction port 5 is provided on the surface 7a, and an exhaust port 6 is provided on the back side surface 7b. A lower pull hood 7 and a wall surface support 8 interposed between the lower pull hood 7 and the upper push hood 3 to support the upper push hood 3, and the suction port 5 and the back side of the surface 7 a of the lower pull hood 7. A partition body 9 is interposed between the exhaust port 6 of the surface 7 b, a ventilation opening 10 is provided in the partition body 9 at a position suspended from the work space 4, and the peripheral end 4 A of the work space 4 and the periphery of the ventilation opening 10 are provided. The above problem can be achieved by making the shortest distance (L) to the end portion 10A the same, averaging the airflow resistance, and making the suction air speed around the suction port 5 uniform and equal to or higher than the set speed.
[Selection] Figure 2

Description

  The present invention sucks harmful gas generated in the work space where people are present without diffusing to the surroundings and eliminates it to the outside due to the laminar flow supplied and the suction air velocity above the diffusion speed of harmful gas in the vicinity of the suction port. The present invention relates to a push-pull type ventilation device.

If hazardous gas is generated in the work space where people are actually working or monitored, the person must not ventilate or eliminate the harmful gas, and do not aim for human safety. Don't be. The usual practice is to enclose a work space, rotate a ventilator to ventilate harmful gases to the outside, and people extend their fingers into the enclosure to work. However, with this method, a large work space cannot be taken, and the work becomes difficult due to the enclosure. Therefore, what is called a push-pull type ventilator that reduces the enclosure of the work space, enables work in an open state, and allows the person to ventilate outside the work space without inhaling harmful gases. There is.

  As shown in FIG. 11, this push-pull type ventilator has a flat pull hood 50 having a cut-off surface at the center of its surface, a work surface 56 and a suction surface 57 around the work surface 56, and an opposing upper portion. The push hood 51 that blows out the uniform flow arranged is connected via a support member 53 having a fan 52 that is a suction mechanism, and pushes the air drawn from the suction surface 57 arranged on the flat surface of the pull hood 50. The exhaust gas is exhausted outside the apparatus without being circulated through the hood 51, and the front surface portion 54 and both side surface portions 55 are opened, and harmful gas generated from the work on the surface of the pull hood 50 is blown out from the push hood 51. Transported to the pull hood 50 without divergence to the outside by a uniform downward flow of a slight wind speed that does not reflect even if it hits the surface of the pull hood 50 Those which also serves as a work table (e.g., see Patent Document 1).

  Then, as shown in FIG. 12, in order to suck harmful gas on the work surface 56 of the flat pull hood 50 from the suction surface 57 around the work surface 56 without diffusing, a corresponding wind speed is secured. Therefore, the pull hood 50 incorporates an airflow guide 58 for directing the airflow sucked from the suction surface 57 toward the fan 52. The airflow guide 58 is disposed toward the exhaust port 59 of the support member 53, thereby ensuring a corresponding wind speed at the suction surface 57 around the work surface 56 and diffusing harmful gases on the work surface 56. It is made possible to suck in from the suction surface 57 without doing so.

  Japanese Patent No. 4551984

  Since the push-pull type ventilator disclosed in Patent Document 1 has a structure in which the fan 52 is built in the support member 53, the exhaust port 59 of the support member 53 located at the connection portion between the support member 53 and the flat pull hood 50. Since the pull hood 50 incorporates an airflow guide 58 for directing the airflow sucked from the suction surface 57 of the surface to the fan 52, the above-mentioned "corresponding wind speed" is ensured. I can do it. However, in this push-pull type ventilator, when the exhaust port connected to the fan 52 is provided on the back side surface 61 other than the surface of the pull hood 50, the airflow guide 58 directed to the fan 52 as described above can cope with it. It will not be possible.

  Therefore, the present invention has been made in view of the above circumstances, and even when an exhaust port connected to a fan is provided on the back side surface other than the front surface of the pull hood, dust or harmful gas generated during work on the pull hood is provided. It is an object of the present invention to provide a ventilator that can be smoothly drawn in without being diffused and discharged to the outside, and can be easily installed and moved easily.

The present invention has been proposed in order to achieve the above-mentioned problems, and is characterized by having the following configuration.
That is, the invention described in claim 1 is an upper push hood for supplying a laminar flow, a lower side surface of the upper push hood which is located below the upper push hood and has a surface as a working space, and a suction port on the surface. A lower pull hood provided with an exhaust port, and a partition body is interposed between the suction port on the surface of the lower pull hood and the exhaust port on the back side surface, and is suspended from the work space of the lower pull hood. Ventilation openings are provided in the partition at the position, and the shortest distance (L) between the peripheral end of the work space and the peripheral end of the ventilation opening is made equal, and the ventilation resistance is averaged, and the suction of the lower pull hood The push-pull type ventilator is characterized in that the suction wind speed around the mouth is kept uniform and at a set speed or higher.

  Further, the invention according to claim 2 is an upper push hood for supplying laminar flow, a lower side surface of the upper push hood which is located below the upper push hood and has a surface as a working space and a suction port on the surface. A lower pull hood provided with an exhaust port, and a partition body is interposed between the suction port on the surface of the lower pull hood and the exhaust port on the back side surface, and is suspended from the work space of the lower pull hood. The length of the partition where the surface of the partition that corresponds to the position is provided with a ventilation opening and the shortest distance (LO) between the outer peripheral end of the suction port and the peripheral end of the ventilation opening is longer than the same length. An auxiliary ventilation opening is provided in the side of the partition facing the generation site to average the ventilation resistance, and the suction wind speed around the suction port of the lower pull hood is kept uniform and above the set speed. It was adapted to a push-pull type ventilation system according to claim.

  The operation of the first problem solving means is as follows. That is, when laminar flow is dropped from the upper push hood toward the work space of the lower pull hood, and air is exhausted from the exhaust port, harmful gas generated from the work on the work space due to the laminar flow is directly exposed to the surface. It leads to the suction port provided in the hood, and from the suction port, harmful gas is sucked into the lower pull hood together with the laminar flow. At that time, the laminar flow containing the harmful gas once enters the partition interposed between the suction port and the exhaust port on the back side surface, and is provided on the back side surface of the lower pull hood through the ventilation opening of the partition body. The exhaust air is exhausted from the exhaust port, but the shortest distance (L) between the peripheral end of the work space and the peripheral end of the vent opening is the same, and the vent resistance is averaged. The suction air speed at is kept uniform and above the set speed, and no harmful gas is diffused.

  When the laminar flow is dropped from the upper push hood toward the work space of the lower pull hood and the air is exhausted from the exhaust port, the work on the work space is caused by the laminar flow. The harmful gas generated from the gas is introduced into the suction port provided on the surface as it is, and the harmful gas is sucked into the lower pull hood from the suction port together with the laminar flow. At that time, the laminar flow containing the harmful gas once enters the partition interposed between the suction port and the exhaust port on the back side surface, passes through the ventilation opening and the auxiliary ventilation opening of the partition, and passes through the lower pull hood. Even though there is a portion where the shortest distance (LO) between the outer peripheral end of the suction port and the peripheral end of the ventilation opening is longer than the same, the length generation site Because the ventilation resistance is averaged by the auxiliary ventilation opening provided on the face of the partition faced, the suction air speed around the suction port of the lower pull hood is kept uniform and above the set speed to diffuse harmful gases There is no.

As described above in detail, the present invention has the following effects.
The invention according to claim 1 does not diffuse dust or harmful gas generated during work on the lower pull hood even when an exhaust port connected to the fan is provided on the back side other than the surface of the lower pull hood. Can be smoothly sucked into the lower pull hood and discharged to the outside, and can be easily installed and moved easily.

  The invention described in claim 2 can obtain the above-described effect even when there is a portion where the shortest distance (LO) between the outer peripheral end portion of the suction port and the peripheral end portion of the ventilation opening is longer than the same.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view (Example 1) of the push pull type ventilator which shows embodiment of this invention. It is the side view (Example 1) which carried out the cross section of a part of push-pull type ventilation apparatus of this invention. It is a disassembled perspective view (Example 1) of the lower pull hood in the push pull type ventilator of this invention. It is a perspective view (Example 1) of the partition body in the lower pull hood of this invention. It is a top view (Example 1) which shows the shortest distance (L) of the peripheral edge part of the working space of the lower pull hood of this invention, and the peripheral edge part of ventilation opening. It is a top view (Example 2) which shows the shortest distance (LO) of the outer peripheral edge part of the suction inlet of the lower pull hood of this invention, and the peripheral edge part of ventilation opening. It is a perspective view (Example 1) of the other partition body in the lower pull hood of this invention. It is a schematic diagram of the front of the experimental push-pull type ventilator which verifies the predominance of this invention. It is a schematic diagram of the lower pull hood of an experimental push-pull type ventilator. It is a schematic diagram of the side surface of the push-pull type ventilator for experiment. It is a perspective view which shows a prior art example. It is a perspective view which shows a prior art example.

  1 to 4, a push-pull type ventilation device 1 includes an upper push hood 3 that supplies a laminar flow 2, and a surface 7a that is located below the upper push hood 3 and that has a surface 7a as a work space 4 and a surface 7a. The lower pull hood 7 is provided with a suction port 5 and an exhaust port 6 on the back side surface 7b other than the front surface 7a. In this embodiment, the lower pull hood 7 and the upper push hood 3 are interposed. The case where the wall surface support 8 that supports the upper push hood 3 is provided will be described. In this push-pull type ventilation device 1, a partition body 9 is interposed between the suction port 5 on the surface 7 a of the lower pull hood 7 and the exhaust port 6 on the back side surface 7 b, and hangs down from the work space 4 of the lower pull hood 7. A ventilation opening 10 is provided in the partition 9 at the position, and the ventilation resistance is averaged by making the shortest distance (L) between the peripheral end portion 4A of the work space 4 and the peripheral end portion 10A of the ventilation opening 10 equal, and the lower pull hood 7 The suction air speed in the vicinity of the suction port 5 is made uniform and higher than the set speed. As a result, the laminar flow 2 that hangs down from the upper push hood 3 leads the harmful gas drifting on the work space 4 of the lower pull hood 7 to the suction port 5 as it is, and is more uniform than the set speed, that is, the harmful gas diffusion speed. The intake air speed is increased so that the harmful gas is not diffused and is sucked into the lower pull hood 7 from the suction port 5.

  The upper push hood 3 is not particularly limited as long as the laminar flow 2 can be supplied. However, since the upper push hood 3 supplies the laminar flow 2, at least the laminar flow generation mechanism 20 is built in, and in addition, the laminar flow generation mechanism 20 is blown. A blower 21 is required for this purpose. The blower 21 does not necessarily need to be built in the upper push hood 3, and if there is an air source from which the necessary air volume and pressure can be obtained, the inlet 22 may be connected to this air source. The laminar flow generating mechanism 20 includes at least a corrugated punching plate 23 formed by corrugating a punching plate having a predetermined aperture ratio, and a 100 ± 20 mesh net member and a lattice louver disposed downstream thereof.

  In the first embodiment, the upper push hood 3 includes the laminar flow generation mechanism 20, the two blowers 21 disposed on the inlet 22 side of the laminar flow generation mechanism 20, the blowers 21 and the layers. The corrugated punching plate 23 includes an airframe 25 having two inflow ports 22 that house the flow generation mechanism 20 and receive air from the outside, and a blowout port 24 that includes a plurality of small hole groups that send out the generated laminar flow 2. The airflow from the blower 21 is buffered by the corrugated wall of the airflow, and the airflow is roughly uniformed by the resistance generated at a predetermined opening ratio of the corrugated punching plate 23, and the quality is further improved by the mesh material and the lattice louver. The laminar flow 2 is sent out from a large number of small holes in the outlet 24.

  As the corrugated punching plate 23 of the laminar flow generating mechanism 20, a corrugated punching plate having a hole area ratio of 20% to 40% is used. In the corrugated punching plate 23 of this embodiment, the hole diameter of the small holes is 3 mm, and the pitch from the center of the small holes to each small hole is 5 mm (φ3 × p5). The hole area ratio of the plate 23 is 33%. In this embodiment, the corrugated punching plate 23 is also corrugated, and the corrugated punching plate 23 has a sawtooth crest pitch of 20 mm. With this corrugated punching plate 23, the whirling air current drifting by the corrugated wall can be corrected, and the wind speed distribution can be roughly adjusted to be uniform by the resistance when passing through countless small holes in the corrugated wall. It is.

  The mesh material is in the range of 100 ± 20 mesh, and is usually a stainless steel wire mesh, but may be made of other materials. This mesh material realizes a higher quality and uniform air flow. On the other hand, the lattice-like louver imparts a certain direction to the high-quality uniform air flow obtained from the mesh material.

  The airframe 25 has a rectangular parallelepiped shape as a whole, and as described above, there are two inflow ports 22 on the upper surface, two air blowers 21 are built in, and an air outlet 24 that is a group of small holes is provided on the lower surface. Then, the laminar flow 2 generated from now on is sent out.

  As shown in FIG. 3, the lower pull hood 7 is a box having a rectangular parallelepiped shape as a whole. In the first embodiment, the surface 7a is recessed so that the cross-sectional shape is an inverted trapezoid, and the recessed portion 30 is provided with the suction port 5 which is a large number of small hole groups in the inclined portion 31 of the peripheral edge, and the plane portion at the center of the surface 7a is used as the work space 4, and the surface 7a is a box made of a back side surface 7b. 32 so that it can be seated on and off. And the partition body 9 is separated from the back side surface 7b and the exhaust port 6 between the suction port 5 of the surface 7a of the lower pull hood 7 and the exhaust port 6 provided in the back side surface 7b in this embodiment. Intervene.

  The partition body 9 has a tray shape, and is provided with the vent opening 10 substantially similar to the work space 4 at a position hanging from the work space 4 on the surface 7a, and the peripheral end 4A of the work space 4 and Ventilation resistance from the suction port 5 to the vent opening 10 with the shortest distance (L) from the peripheral end 10A of the vent opening 10 being the same, that is, L1 = L2 = L3 = L4 shown in FIG. And the suction air speed around the suction port 5 of the lower pull hood 7 is made uniform. Then, the suction wind speed may be set to be equal to or higher than a predetermined set speed, that is, higher than the diffusion speed of harmful gas. The vent opening 10 is formed of a large number of small hole groups as in the case of the suction port 5.

  Therefore, if the exhaust port 6 provided on the back side surface 7b of the lower pull hood 7 is connected to an exhaust source such as an exhaust fan by a duct and exhausted, the suction port surrounding the peripheral end 4A of the work space 4 is provided. 5, air is sucked in. At that time, since the shortest distance (L) between the peripheral end portion 4 </ b> A of the work space 4 and the peripheral end portion 10 </ b> A of the ventilation opening 10 is the same, the ventilation resistance is also averaged. If the air flow rate of the exhaust source is set so that the suction air speed from the suction port 5 becomes uniform and the suction air speed becomes larger than the diffusion rate of harmful gas, the suction port 5 is caused by the laminar flow 2 from the upper push hood 3. The harmful gas drifting on the work space 4 connected to the air is introduced into the lower pull hood 7 from the suction port 5 without being diffused, and is exhausted to the outside through the duct from the exhaust port 6.

  In the work space 4, it is customary to lay the work plate 33 when actually working. The work space 4 is a flat portion at the center of the hollow portion 30 of the lower pull hood 7 and the periphery thereof is surrounded by the inclined portion 31, so that the work plate 33 is inclined with a deviation from the work space 4 that is the flat portion. Since it is difficult to get on the portion 31 and even if it gets on, it is difficult to work, so the operator can make corrections immediately and the suction port 5 provided in the inclined portion 31 is not blocked by the work plate 33. . Therefore, the workability is further improved by forming the recessed portion 30 by recessing the surface 7a of the lower pull hood 7, making the plane portion the working space 4, and providing the suction port 5 in the inclined portion 31. In addition, the work plate 33 does not block the suction port 5 of the inclined portion 31, so that the harmful gas drifting on the work space 4 can be more stably eliminated.

  The depth of the work space 4 in the center of the recess 30 of the lower pull hood 7 is in the range of 10 mm to 20 mm. And since the thickness of the work board 33 laid on the work space 4 is also in the range of 10 mm to 20 mm, even if the work board 33 is laid on the work space 4, it becomes almost the same height, It is easy to work without lowering the position. Furthermore, the harmful gas can be guided into the suction port 5 of the inclined portion 31 without passing through it and sucked into the lower pull hood 7, and harmful gas can be eliminated more reliably. it can.

  The wall surface support 8 has a grooved steel shape, and as described above, is interposed between the lower pull hood 7 and the upper push hood 3 to support the upper push hood 3. The wall surface support 8 has a non-groove surface 8 a side as a wall surface interposed between the upper push hood 3 and the lower pull hood 7.

  6 and 7 show another embodiment of the partition body of the lower pull hood in the push-pull type ventilator of the present invention, and the difference between this partition body 9A and the partition body 9 shown in FIGS. When a portion where the shortest distance (LO) between the outer peripheral end portion 5A of the suction port 5 and the peripheral end portion 10A of the ventilation opening 10 is longer than the same occurs, for example, when LO1 <LO2 in FIG. For example, a plurality of auxiliary ventilation openings 34 are provided in the side surface portion of the partition body 9A shown in FIG. 7 on the side surface portion of the partition body 9A facing the length generation portion to average the ventilation resistance, and the suction port 5 of the lower pull hood 7 is provided. The suction air speed in the periphery is uniform and higher than the set speed. Thus, even if there is a portion where the shortest distance between the outer peripheral end portion 5A of the suction port 5 and the peripheral end portion 10A of the ventilation opening 10 is longer than the same, the ventilation resistance can be averaged by the auxiliary ventilation opening 34, and the lower pull hood 7 The suction air velocity around the suction port 5 is kept uniform and above the set speed, and no harmful gas is diffused.

Next, since the superiority of the push-pull type ventilator of the present invention was verified, the situation will be described.
8 to 10 are schematic views of an experimental push-pull type ventilator to which the second embodiment of the present invention is applied, and measurement is performed under the following conditions using this experimental device. First, the test chamber is sufficiently ventilated, and the push-pull type ventilator for experiments shown in FIGS. 8 to 10 is installed. A 3.04 wt% acetaldehyde standard gas (manufactured by Sumitomo Seika Co., Ltd., N2 balance) was used as the harmful gas, and the flow rate was 1 L / min. A standard gas was introduced and generated from an acetaldehyde gas cylinder to each experimental point with a silicon hose. As shown in FIGS. 8 and 9, each experimental point is a center A of the work space, A-0 on the work space, A-200 vertically 200 mm above A-0, and A-600 similarly 600 mm above. Furthermore, the upper part of 1200 mm was set to A-1200. Furthermore, B-0 was defined on the boundary between the work space and the suction port.

  At each experimental point described above, acetaldehyde was generated, and after 5 minutes from the generation, that is, from 6 minutes to 15 minutes, the acetaldehyde concentration in the exhaust duct connected to the lower pull hood was measured every minute. . The concentration of acetaldehyde was measured with a photoacoustic gas monitor (INNOVA, 1312-1). In addition, from the result measured at each experimental point, the average value for 8 times excluding the maximum value and the minimum value was taken as the measurement result.

As a control example of the experiment of the present invention according to FIGS. 8 to 10, the partition body is not provided at all in the lower pull hood. Otherwise, the acetaldehyde concentration is measured under the same conditions as those of the experiment example of the present invention according to FIGS. Went. The above measurement results are shown in Table 1.

  From the measurement results of Table 1, it can be said that the present invention was superior to the control example at any experimental point, and it was verified that the diffusion of acetaldehyde, which is a harmful gas, was effectively prevented.

Next, the operation state of the push-pull type ventilator 1 having the above configuration will be described in detail.
First, when the power is turned on, the two blowers 21 of the upper push hood 3 are operated, air enters from the two inlets 23, and the corrugated punching plate 23, the netting material, and the lattice louvers of the laminar flow generating mechanism 20 are aired. In the process of passing, a laminar flow 2 having a uniform and high wind speed is formed. The laminar flow 2 is sent out from the outlet 24, and harmful gas drifting from the work on the work plate 33 laid on the work space 4 is pushed downward by the laminar flow 2 and the suction port 5 The laminar flow 2 containing the harmful gas once enters the partition body 9 interposed between the suction port 5 and the exhaust port 6. Then, the air is exhausted from the exhaust port 6 provided on the back side surface 7 b of the lower pull hood 7 through a duct through the ventilation opening 10 of the partition 9. At that time, the shortest distance (L) between the peripheral end portion 4A of the work space 4 and the peripheral end portion 10A of the ventilation opening 10 is made the same, and the ventilation resistance is averaged, so the suction around the suction port 5 of the lower pull hood 7 Since the wind speed is uniform and above the set speed, that is, above the diffusion speed of the harmful gas, the harmful gas is not diffused.

  As shown in FIG. 6, the push-pull type ventilator 1 has a portion (LO1) where the shortest distance (LO) between the outer peripheral end 5A of the suction port 5 and the peripheral end 10A of the ventilation opening 10 is longer than the same. Even when <LO2) occurs, ventilation resistance can be averaged by the auxiliary ventilation opening 34 provided in the side surface portion of the partition 9A facing the length generation site, and suction around the suction port 5 of the lower pull hood 7 Since the wind speed is kept uniform and above the set speed, no harmful gas is diffused.

  As described above, the first and second embodiments of the present invention have been described. However, the specific configuration is not limited to this, and for example, there is no wall surface support, and it is installed using the ceiling, floor, or wall of a building. It should be understood that modifications and additions within the scope of the present invention and other combinations in the claims can be made as appropriate.

  The push-pull type ventilator of the present invention can smoothly disperse dust or harmful gas generated during work on the lower pull hood even when the lower pull hood is directly provided with an exhaust port connected to the suction mechanism. When it can be sucked into and discharged to the outside, and simple installation and movement are desired, the applicability becomes extremely high.

DESCRIPTION OF SYMBOLS 1 Push-pull type ventilator 2 Laminar flow 3 Upper push hood 4 Work space 4A Perimeter end 5 Suction port 5A Outer end 6, 59 Exhaust port 7 Lower pull hood 7a Surface 7b, 61 Back side 8 Wall support 8a Non-groove surface 9, 9A Partition body 10 Ventilation opening 10A Circumferential end 20 Laminar flow generation mechanism 21 Blower 22 Inlet 23 Corrugated punching plate 24 Outlet 25 Airframe 30 Recessed portion 31 Inclined portion 32 Box 33, 60 Work plate 34 Auxiliary ventilation opening DESCRIPTION OF SYMBOLS 50 Flat-shaped pull hood 51 Push hood 52 Fan 53 Support member 54 Front part 55 Side part 56 Blocking surface 57 Suction surface 58 Airflow guide

Claims (2)

  An upper push hood that supplies laminar flow, a lower pull hood that is located below the upper push hood and that has a surface as a working space, a suction port on the surface, and an exhaust port on the back side other than the surface, The partition body is interposed between the suction port on the surface of the lower pull hood and the exhaust port on the back side surface, and a ventilation opening is formed in the surface portion of the partition body corresponding to a position suspended from the work space of the lower pull hood And equalizing the shortest distance (L) between the peripheral end of the working space and the peripheral end of the vent opening to average the ventilation resistance, and uniform the suction air speed around the inlet of the lower pull hood and A push-pull type ventilator characterized by maintaining at a set speed or higher.   An upper push hood that supplies laminar flow, a lower pull hood that is located below the upper push hood and that has a surface as a working space, a suction port on the surface, and an exhaust port on the back side other than the surface, The partition body is interposed between the suction port on the surface of the lower pull hood and the exhaust port on the back side surface, and a ventilation opening is formed in the surface portion of the partition body corresponding to a position suspended from the work space of the lower pull hood And when the portion where the shortest distance (LO) between the outer peripheral end portion of the suction port and the peripheral end portion of the ventilation opening is longer than the same is generated, the side surface of the partition facing the length generation portion An auxiliary ventilation opening is provided in the part to average the ventilation resistance, and the suction air speed around the suction port of the lower pull hood is kept uniform and above the set speed. That push-pull type ventilation system.

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