JP2010096497A - Constant flow blowoff push hood - Google Patents

Abstract

The present invention provides a pull hood that can stably blow a uniform flow and is suitable for use in a desktop ventilation device for work.
In a push hood that blows out a uniform flow, a flow path adjusting plate for supplying the air flow to the rectifying mechanism by changing the flow direction without directing the air flow from the fan directly to the blowing portion provided with the rectifying mechanism. Push hood characterized by having built-in.
[Selection] Figure 4

Description

  The present invention relates to a ventilator, and more particularly to a uniform blowout push hood.

  Conventionally, as a local ventilation device, a local exhaust device only for suction and a push-pull type ventilation device that forms a ventilation flow by blowing and sucking are known. Both are used as measures to prevent workers from being exposed to harmful substances in areas where harmful substances are generated. An air purifier is also widely used as a simple indoor air purifier.

  Many of the conventional local exhaust devices are provided with a suction hood in the vicinity of a divergence source of harmful substances or the like, that is, in the vicinity of a work point, so that workability is often deteriorated. For example, the draft corresponds to a local exhaust device, but since the work is performed with the hand placed in the draft, the workability is poor, and in particular, when performing precise work, the viewpoint is far from the hand, so it is not practically used.

  In addition, the conventional air cleaner can be placed at a position where workability does not deteriorate, that is, away from the work point. Is difficult.

  In addition, since the conventional push-pull type ventilation device can ventilate a wide range without impairing workability, it is possible to reduce the risk of the operator being exposed to harmful substances. However, since the conventional push-pull type ventilator is a fixed facility, it cannot be easily moved, and every time a production line or layout in a factory or the like is changed, a large-scale work tends to be required. In addition, since it is necessary to provide independent fixing equipment of two systems of push hood and pull hood, that is, a hood that blows out airflow and a hood that sucks in air, the installation cost tends to increase.

  The present inventor is a push hood that can be used for any of the above-mentioned local ventilation devices [Patent Document 1]. A rectifying mechanism and a blow-off portion are arranged from the fan (windward) side to a honeycomb, punching metal, punching metal. A device that generates a uniform flow by adopting a combination structure of honeycomb has been proposed.

JP 2001-289500 A

  An object of the present invention is to provide a uniform flow-out push hood suitable for use in a desktop ventilation device having excellent workability.

  In the push hood that blows out a uniform flow, the air flow from the fan is not directed directly to the blowout part equipped with the rectifying mechanism, but the flow direction is changed and the flow path adjusting plate for supplying the air flow to the rectifying mechanism is incorporated. It is a push hood characterized by being.

  Secondly, in the push hood incorporating the flow path adjusting plate for changing the flow direction of the air flow from the fan, the flow direction of the air flow from the fan is directed to the side wall by the flow path adjusting plate. It is said push hood characterized by changing the flow direction by this.

  Thirdly, the present invention connects the above-described push hood blow-off surface and the pull hood having a suction surface at the opposite position via a support member having a built-in suction mechanism to open the front and both side portions. This is a tabletop ventilation device.

  4thly this invention is said desktop type ventilation apparatus with which the pull hood becomes a structure which has a cutoff surface in the surface center of the suction surface, and has a suction surface in the periphery.

  5thly this invention is said desktop type ventilation apparatus with which the pull hood incorporates the airflow guide which directs the airflow sucked from the surface of the suction surface to a suction mechanism.

  By using the push hood of the present invention, it is possible to stably provide a uniform flow, and it is possible to remarkably improve the workability when performing work involving the divergence of harmful substances on the table.

The perspective view which shows an example of a desktop type ventilator. The schematic side view which shows the state which attached the duct to the apparatus of FIG. Side surface explanatory drawing which shows the state which attached the filter to the apparatus of FIG. Side surface explanatory drawing which shows an example of push hood. It is explanatory drawing which shows another example of push hood, A is a front view, B is a side view. Plane explanatory drawing which shows the pull hood which incorporates an airflow guide. The inside of the pull hood with a built-in airflow guide will be described. Schematic explanatory drawing explaining the flow direction of airflow.

  In the figure, 1 is a pull hood, 2 is a push hood, 3 is a support member, 4 is a frame, 5 is a suction mechanism, 6 is a rectifying mechanism, 7 is an outlet, 8 is a fan, 9 is a dust filter, and 10 is a blocking surface. , 11 is a suction surface, 12 is an exhaust port, 13 is a fluorescent lamp, 14 is an operation switch, 15 is a lighting switch, 16 is a flow control board, 17 is an airflow guide, 18 is a duct, and 19 is a filter.

The present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view showing an example of a desktop ventilation device.
A push hood 2 that blows a uniform flow is disposed on the opposing upper portion of the flat pull hood 1, and both are connected via a support member 3. The support member 3 is usually composed of a housing structure of the main body and a frame 4. A suction mechanism 5 such as a sirocco fan is built in the main body and sucks the airflow sent from the push hood 2 through the pull hood 1. Further, a duct (FIG. 2) and / or a filter (FIG. 3) are usually provided in the main body of the support member 3, and the sucked airflow is exhausted to the outside through the duct or cleaned through the filter. .

  The push hood 2 is a push hood that blows out an airflow in a state close to a laminar flow that flows at a constant flow rate in a certain direction, that is, a uniform hood, and has a blowout port provided with a rectifying mechanism (rectifying unit). A fan, such as an axial flow fan, having a blowout port 7 having a rectifying mechanism 6 and a fan 8 is usually operated to take in indoor air through the dust filter 9 through the push hood 2 and pass it through the rectifying mechanism. After uniforming the distribution and the wind direction, the air is allowed to reach the surface of the pull hood 1 from the air outlet 7 as a downward flow (down flow) with a slight wind speed. At that time, in order to generate a more uniform air flow, the air flow from the fan 8 is not directly directed to the rectifying mechanism 6, but a flow path adjusting plate 16 is provided as shown in FIGS. The flow direction is changed once or more, preferably twice or more to reach the rectifying mechanism. As shown in the figure, the flow path adjusting plate 16 directs the direction of the airflow from the fan toward the side wall and changes the flow direction there.

  Conventionally, pull foods of various sizes and shapes are known, and many of them use a metal mesh, a punched iron plate, a filter or other perforated plate as a suction surface. Naturally, the more uniform the wind speed distribution of the pull hood, the more the required suction air volume can be reduced, thereby making it possible to keep the equipment cost low.

  Since the pull hood 1 also serves as a work table, it is preferably flat and thin as much as possible. The surface structure and material of the suction surface can be appropriately selected from conventional ones. However, it is preferable that the surface of the pull hood 1 is a blocking surface 10 at the center and a suction surface 11 having a suction function around this surface. Incidentally, only a part of the suction surface 11 of FIG. 1 is shown in a porous shape. The size of the blocking surface 10 is preferably 20 to 70%, particularly about 30 to 50% of the surface area of the suction surface 11. The blocking surface 10 is a flat surface having no suction function, and is usually formed of a metal or a plastic plate. The downflow airflow from the push hood 2 mainly reaches the blocking surface, but the downflow airflow is slightly breeze, so it is not reflected and flows in a scattered manner in all directions so as to crawl the surface of the blocking surface 10 Is sucked from the blowing surface 11. This suction is performed by a suction mechanism 5 such as a sirocco fan built in the main body of the support 3. By this suction, indoor air is also sucked simultaneously with the downflow airflow.

  It is preferable to provide an airflow guide at the lower part (back) of the blocking surface 10 of the pull hood 1. The airflow guide is for indicating a mechanism for suppressing the degree of reduction of the suction air speed on the far side of the suction surface 11 of the pull hood 1 as compared with the side closer to the suction mechanism 5, and delimits the inside of the pull hood 1. As long as it shows the upper function, its structure and arrangement are not particularly limited.

  6 and 7 show an example of the airflow guide. When the suction air flow by the suction mechanism 5 is flowing at a substantially uniform speed, the air flows at A1, A2, and A3 in the same manner at a substantially uniform wind speed. Here, the wind speed at each point refers to the wind speed flowing through the suction hood. In order to suck room air from the suction surface, the wind speed is lower than A1 to A3 in B1, B2, and B3, but flows at a substantially uniform wind speed. Further, in C1 and C3, the wind speed is lower than B1 to B3 for the same reason, but in C2, the indoor air is not sucked by the blocking surface 10, and further, the airflow guide 17 does not cause the air to enter and exit from C1 and C3. It flows at a higher wind speed than C3. As a result, the wind speed of D2 flows faster than D1 and D3, which always sucks room air between B and D, and flows at a wind speed almost equal to that of C2. Since this wind speed is proportional to the wind speed at which room air is sucked from the suction surface 11, the wind speed sucked from the suction surface 11 near D2 is faster than that near D1 and D3. Therefore, by combining the blocking surface 10 and the airflow guide 17, it is possible to suppress a decrease in wind speed even at a position far from the suction fan as in D2. Further, in order to suppress the decrease in the wind speed of D1 and D3 as much as possible, it is effective to shorten the length of the two outer air guides among the four air flow guides 17 as shown in the figure. Further, as shown in the drawing, the two inner airflow guides are sucked in and not extended to the tip of the hood, which also has the effect of increasing the wind speed of D1 and D3, and it is desirable to keep it at the tip position of the blocking surface.

Although the room air cannot be sucked directly from the suction surface 11 at the portion where the blocking surface 10 is present, the push-pull ventilation allows the downflow airflow to be removed from the air present on the upper surface of the blocking surface 10. Since it conveys to the suction surface 11 of the outer periphery of the interruption | blocking surface 10, it becomes possible to suction indirectly. The state is shown in FIG.
The dimensions and the like of each member of the tabletop ventilation device can be appropriately determined depending on the work contents and the like, and one specific example is shown below.

After the indoor air (2.9 m ³ / min) sucked from the dust filter 9 (600 mm × 150 mm) by the axial fan 8 built in the push hood 2 is uniformly rectified through the rectifying mechanism 6, the wind speed distribution and the wind direction are rectified. Then, the air is blown out from the air outlet 7 (600 mm × 200 mm) as a downflow with a slight wind speed (1.5 to ⁴ m ³ / min). The downflow airflow reaches the lower blocking surface 10 (500 mm × 325 mm: area corresponding to 44% of the suction surface 11). At this time, since the downflow airflow is a slight wind speed, the downflow airflow is not reflected and flows in a dispersed manner in all directions so as to crawl the surface of the blocking surface 10. On the other hand, from the suction surface 11 (punched iron plate: size = about 768 mm × about 487 mm: hole diameter = φ2 mm: hole pitch = 3.5 mm) located around the blocking surface 10, the sirocco fan 5 causes room air (4 To 10 m ³ / min). At this time, the downflow airflow is also dispersed around the blocking surface 10 and then sucked from the suction surface 11 together. The sucked air passes through the airflow guide 17 (315 mm × 24.8 mm × 5 mm × 2: 235 mm × 24.8 mm × 5 mm × 2), passes through the sirocco fan 5, and is discharged from the exhaust port 12.

  In addition, when the work which handles harmful substances is performed on the blocking surface 10 or when odor is generated on the upper surface of the blocking surface 10, since the air containing these is sucked from the suction surface 11, You may attach the filter which removes an odor, or connect a duct and exhaust to the outdoors. Further, when the push hood 2 reduces the illuminance at hand, it is desirable to attach a lighting fixture such as a fluorescent lamp 13 or the like.

Claims (5)

  In the push hood that blows out a uniform flow, the air flow from the fan is not directed directly to the blowout part equipped with the rectifying mechanism, but the flow direction is changed and the flow path adjusting plate for supplying the air flow to the rectifying mechanism is incorporated. A push hood characterized by   In a push hood incorporating a flow path adjustment plate for changing the flow direction of the airflow from the fan, the flow direction is changed by directing the flow direction of the airflow from the fan toward the side wall by the flow path adjustment plate. The push food according to claim 1 characterized by things.   The table | surface which connects the blow hood of the push hood of Claim 1, and the pull hood which arranged the suction surface in the position which opposes it via the support member which incorporated the suction mechanism, and makes the front part and both side parts open. Type ventilator.   The desktop ventilation apparatus according to claim 3, wherein the pull hood has a blocking surface in the center of the suction surface and a suction surface in the periphery thereof.   The desktop type ventilator according to claim 3 or 4, wherein the pull hood incorporates an airflow guide for directing the airflow sucked from the surface of the suction surface to the suction mechanism.

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