JP2001289500A - Uniform air outlet unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a uniform air outlet unit having simple structure in which the area of air outlet and the size of a rotary impeller generating a spiral flow are not required to be adjusted from part to part. SOLUTION: A ventilation resistor 3 comprising a honeycomb plate having a large number of wall bodies intersecting in the spiral direction and passing air in the axial direction or a filter folded in zigzag to form wall bodies is disposed just in front of a rotary impeller 2 generating a spiral flow on the air discharging side and porous plates 4, 5 each having a uniform porosity over the entire surface are disposed further in front thereof on the air discharging side while being spaced apart slightly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for uniformly generating a blown air flow in a dust-generating site such as welding or polishing, or a push-pull type ventilator installed in a workplace using an organic solvent such as painting or cleaning. The present invention relates to an air flow blowing device.

[0002]

2. Description of the Related Art Conventionally, a swirling flow sent from a fan is sent into a box having an outlet through an air supply duct or the like.
First and second perforated plates covering the outlet of the box and a honeycomb-shaped laminar flow plate are provided, and the opening ratio of the first and second perforated plates on the upstream side is determined by comparing the opening ratio of the surface with the first and second perforated plates. Japanese Patent Publication No. 3-79618 discloses a uniform air flow blowing device in which a uniform air flow is blown out from a blowing port by changing each part. This uniform air flow blowing device requires construction work to install air supply ducts in factories, etc., and the distribution of holes in the perforated plate must be adjusted according to the area of the air outlet and the capacity of the fan. Was.

In addition, a centrifugal blower is disposed inside a main body having an air inlet and an air outlet on opposing surfaces, and a blown air flow from the centrifugal blower is provided between the centrifugal blower and the air outlet. Japanese Patent Application Laid-Open No. Hei 10-292925 discloses a blower unit having a blow-off air passage surrounding a centrifugal blower and guided in an axisymmetric flow. This does not require duct work, but its structure is complicated because the swirl flow blown from the centrifugal blower is removed by the stationary blades and diffuser formed in the blown air, and the stationary blades and diffuser are large in size. There is a drawback that it must be molded according to the requirements. Also, this one
Although a resistor is provided at the air outlet and the technology for making the wind speed distribution at the air outlet uniform is provided, this resistor also has a resistance depending on the area of the air outlet, the size of the centrifugal blower, and the like. The distribution must differ from place to place.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a uniform air flow blowing device which has a simple structure and does not require adjustment of components for each area of an air outlet and the size of a rotary impeller. Make it an issue.

[0005]

SUMMARY OF THE INVENTION A uniform air flow blowing device according to the present invention has a large number of walls intersecting in the spiral direction of the rotary impeller on a surface immediately before the exhaust side of the rotary flow generating rotary impeller. At the same time, a ventilation resistor that transmits air in the axial direction is installed, and furthermore, a perforated plate with a uniform porosity is installed over the entire surface, with a slight gap in front of the exhaust side of the ventilation resistor. You. A first embodiment of the ventilation resistor is a honeycomb plate, and a second embodiment is a filter in which a sheet is folded in a zigzag shape to form the wall, for example, a HEPA filter. A large number of holes having a uniform hole diameter and a uniform pitch are formed in the perforated plate over the entire surface. The number of perforated plates may be plural, but if the perforated plate is too large, not only the cost increases but also the thickness of the apparatus increases, so it is appropriate to use one or two perforated plates. Then, the ventilation resistor and the perforated plate are arranged in parallel to each other, and are incorporated together with the spiral flow generating rotary impeller into the inside of the box having open front and rear surfaces.

[0006] The swirling flow sent from the spiral flow generating rotary impeller hits the wall of the ventilation resistor, is blocked, and blows out from the front surface of the ventilation resistor as an axial flow. The airflow blown out from the ventilation resistor is resisted by the perforated plate, reduces the pressure difference between the outer peripheral portion and the central portion, and blows out from the holes of the perforated plate as a uniform airflow having a substantially uniform velocity distribution. Here, the uniform air flow means that in a cross section perpendicular to the flow, the flow velocity is constant such that no practical problem occurs throughout the cross section. (1982, published by the Japan Society of Air Conditioning and Sanitary Engineers, written by Taro Hayashi), it is sufficient that the variation in the speed distribution be within ± 20% of the average value. If a filter is used as the ventilation resistor, the blown airflow can be cleaned without installing a separate dust filter. Further, a honeycomb plate may be installed in parallel with a slight gap in front of the exhaust side of the perforated plate. The blowing direction of the airflow that has passed through the perforated plate is adjusted by the honeycomb plate.

[0007]

FIG. 1 shows a first embodiment of the present invention. The uniform air blowing device has a box 1 with open front and rear surfaces.
The spiral flow generating rotary impeller 2 is installed at the rear of the box 1, and the ventilation resistance of the first honeycomb plate 3 is provided on the surface immediately before the exhaust side of the spiral flow generating rotary impeller 2. The first and second perforated plates 4 and 5 having a uniform porosity over the entire surface are provided on the exhaust side front surface of the first honeycomb plate 3 with the body installed.
And a second honeycomb plate 6 on the front side on the exhaust side.
Is configured.

The first and second honeycomb plates 3 and 6 are made of metal or synthetic resin, and a large number of walls defining cells intersect in the spiral direction of the spiral flow generating rotary impeller 2 to form the cells. The air is transmitted in the axial direction of the spiral flow generating rotary impeller 2 through a number of through holes formed along the axial direction of the spiral flow generating rotary impeller 2 formed therebetween. Since the cells of the honeycomb plate are hexagonal, the walls constituting the cells of the first and second honeycomb plates 3 and 6 include a spiral flow generating rotary impeller 2.
Some of them may be along the spiral direction, but it is sufficient that many other walls intersect with the spiral direction. The first and second perforated plates 4 and 5 are made of a metal plate, a synthetic resin plate, or the like in which a large number of holes having a uniform diameter and pitch are formed. And the first
The honeycomb plate 3, the first and second perforated plates 4 and 5, and the second honeycomb plate 6 are arranged parallel to each other with a slight space therebetween.

(Experiment 1) An experiment was conducted in which air was blown from the uniform air flow blowing device, and the velocity distribution of the air flow obtained by the experiment is shown in Table 1. Opening surface of box 1 610 mm × 610 mm Diameter of spiral flow generating rotary impeller 2 350 mm First and second honeycomb plates 3, 6 Material Aluminum Wall thickness 0.025 mm Cell size 3.2 mm Thickness 20 mm First and FIG. Material of SUS 304 Pore size 1.5 mm Pitch 3 mm Open area ratio 22.8% Thickness 1 mm Between first honeycomb plate 3, first porous plate 4, second porous plate 5 and honeycomb plate 6 The distance is 15 mm.

[0010]

[Table 1] As a result, the velocity of the airflow blown out from the uniform airflow blower is 0.999 m / s on average, while the maximum value is 0.999 m / s.
+ 10.1% at 90 m / s, minimum value is 0.851 m / s
Was -9.3%, indicating that a good uniform air flow was being blown out.

On the other hand, Comparative Example 1 has the same configuration as that of the first embodiment except that the first honeycomb plate 3 is removed.
Table 2 shows the velocity distribution of FIG.

[0012]

[Table 2] In this case, the velocity of the air flow is + 14.4% at the maximum value of 1.096 m / s and -27.1% at 0.698 m / s against the average value of 0.958 m / s, The average value ± 20%, which is a condition of uniform air flow, is not satisfied. From the above, it is possible to confirm the effect of the first honeycomb plate 3 installed on the surface immediately before the exhaust side of the spiral flow generating rotary impeller 2.

FIG. 2 shows a second embodiment of the present invention. In the uniform air blowing device, a ventilation resistor composed of a filter 7 is installed immediately before the exhaust side of the spiral flow generating rotary impeller 2 ′, and the opening ratio is entirely formed on the front side of the filter 7 on the exhaust side. Is provided with one uniform porous plate 4 ', and further, a honeycomb plate 6' is provided on the front side on the exhaust side thereof, and is incorporated in a box 1 'having open front and rear surfaces. The filter 7 is a HEPA filter in which a large number of linear walls formed by folding a sheet made of glass fiber in a zigzag shape many times are arranged in parallel. It is arranged so as to intersect the spiral direction of the generating rotary impeller 2 ′ and transmit air in the axial direction. The configurations of the perforated plate 4 'and the honeycomb plate 6' are the same as those of the perforated plate 4 and the honeycomb plate 6 in the first embodiment.

(Experiment 2) An air blowing experiment was performed from the uniform air blowing device in the second embodiment, and the velocity distribution of the air flow is shown in Table 3. The diameter of the spiral flow generating rotary impeller 2 'was 500mm, the thickness of the filter 7 was 66mm, the distance between the filter 7, the perforated plate 4' and the honeycomb plate 6 'was 15mm. Other conditions were the same as those in Experiment 1.

[0015]

[Table 3] In this experiment, the velocity of the airflow was 0.815 m / average.
s, the maximum value is 0.906 m / s at + 11.1%,
The minimum value was -9.2% at 0.741 m / s, and it was found that a favorable uniform air flow was obtained.

Comparative Example 2 having the same configuration as the second embodiment except that the order of the filter 7 and the perforated plate 4 'was changed.
Table 4 shows the velocity distribution of FIG.

[0017]

[Table 4] In this case, the velocity of the air flow is + 20.2% at 0.946 m / s and -28.0% at 0.566 m / s, while the average value is 0.789 m / s. The average value ± 20%, which is a condition of uniform air flow, is not satisfied. This shows that the order of the filter 7 and the perforated plate 4 'is important.

The thickness and cell size of the honeycomb plate,
The thickness of the filter, the number of perforated plates, the hole diameter, the pitch and the thickness, the distance between the components, and the like can be appropriately changed depending on the installation location of the uniform air flow blowing device, the diameter and the capability of the spiral flow generating rotary impeller, and the like. . Further, as the filter, a filter in which a number of linear walls folded in a zigzag shape are arranged in parallel may be used, and the walls may be arranged so as to intersect the spiral direction. Further, the honeycomb plate installed on the front surface of the perforated plate can be omitted.

[0019]

According to the first aspect of the present invention, the swirling flow sent from the spiral flow generating rotary impeller is blocked by hitting the wall of the ventilation resistor, and the outer peripheral portion and the center are prevented by the resistance of the perforated plate. It is possible to reduce the pressure difference between the airflow section and the airflow, and to convert the airflow into a uniform airflow having a substantially uniform velocity distribution. Further, since the swirling flow is removed first, it is possible to make the velocity distribution uniform with a small number of sheets even if a perforated plate having a uniform opening ratio is used. it can. Furthermore, even if the diameter of the spiral flow generating rotary impeller changes, the same component can be used only by changing the area, so that it is not necessary to adjust the component for each size of the spiral flow generating rotary impeller. .

According to the third aspect of the present invention, since the ventilation resistor has a dust removing function, a clean uniform air flow is supplied.
There is no need to separately provide a dust filter for purifying air, so that an increase in the thickness of the apparatus can be suppressed. According to the fourth aspect of the present invention, the direction of the air flow blown out of the perforated plate can be uniformly adjusted by passing the air flow through the through holes of the honeycomb plate.

[Brief description of the drawings]

FIG. 1 is a sectional view of a uniform air flow blowing device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a uniform air flow blowing device according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a main part of Comparative Example 1.

FIG. 4 is a sectional view of a main part of Comparative Example 2.

[Explanation of symbols]

 Reference Signs List 1 box 2 spiral flow generating rotary impeller 3 first honeycomb plate (ventilation resistor) 4 first porous plate 5 second porous plate 6 second honeycomb plate 1 'box 2' spiral flow generating rotary blade Car 4 'perforated plate 6' honeycomb plate 1 filter

Claims (4)

[Claims] 1. A ventilation resistor that has a large number of walls intersecting in the spiral direction of a rotary impeller and that is permeable to air in an axial direction is provided on a surface immediately before the exhaust side of the spiral flow generating rotary impeller. A uniform air flow blowing device, further comprising a perforated plate having a uniform porosity throughout the entire surface of the ventilation resistor, with a slight gap in front of the exhaust side of the ventilation resistor. 2. The uniform air blowing device according to claim 1, wherein the ventilation resistor is formed of a honeycomb plate. 3. The uniform air blow-off device according to claim 1, wherein the ventilation resistor comprises a filter in which a sheet is folded in a zigzag shape to form the wall. 4. The uniform air flow blowing device according to claim 1, wherein a honeycomb plate is provided at a slight interval in front of the exhaust side of the perforated plate.