JP6804734B2 - Push-pull ventilation type local exhaust system - Google Patents

Description

The present invention is a push-pull ventilation type local exhaust that blows out air with a uniform wind speed distribution on the push side and sucks and exhausts the air in the ventilation area on the pull side so as not to diffuse harmful substances in the ventilation area to the surroundings. Regarding the device.

In research facilities and production plants, it is necessary to apply a local exhaust method as a ventilation method to prevent exposure when workers handle organic solvents such as formaldehyde.

A local exhaust device that realizes the above method collects and exhausts harmful substances (dust and gas) generated in a specific place without scattering them to the surroundings by using an air flow. When using such a local exhaust system, it is necessary to partition the contaminated area. For this reason, there are problems that the cost for providing the section is high and the workability is deteriorated. Further, since a large amount of air is sucked and exhausted, there is a problem from the viewpoint of energy saving.

Therefore, in recent years, a push-pull ventilation type local exhaust system has been proposed in order to solve such a problem. With such a device, it is not necessary to partition the contaminated area, and it is possible to work in an open space.

For example, in Patent Document 1 (Japanese Unexamined Patent Publication No. 2005-337562), in a push-pull type ventilator in which a push hood having a uniform air flow blowing mechanism and a pull hood having a suction / exhaust mechanism are combined, the push hood is rectangular. It has an opening and one fan in the center, and a perforated plate with a unit hole area of 100 to 1000 mm ² and an aperture ratio of 15 to 80% is placed only in the center of the front surface of the fan, and then rectified. A push-pull type ventilator characterized by using a push hood with a built-in fan in which members are arranged is disclosed.
Japanese Unexamined Patent Publication No. 2005-337562

However, even in the conventional push-pull ventilation type local exhaust device disclosed in Patent Document 1, the temperature-controlled air in the room is exhausted to the outside, which causes a problem of poor energy efficiency.

The present invention solves the above-mentioned problems, and the push-pull ventilation type local exhaust device according to the present invention includes a uniform flow blowing hood on the push side that blows out a uniform air flow and the uniform flow blowing hood. and local exhaust table is a pull side corresponding to the flow balloon hood, in a push-pull ventilation type local exhaust device made up of, from said uniform flow blowout hood, Callout uniform air flow by the outside air that has not been temperature adjustment treatment The uniform flow blowing hood is composed of a housing, and the inside of the housing has an air diffusion unit that diffuses air and a rectifying unit that rectifies the air diffused by the air diffusion unit. However, the rectifying unit comprises a resistance plate that collides with the supplied air and makes the air have a predetermined wind velocity distribution, and a perforated plate that receives the air having a predetermined wind velocity distribution by the resistance plate. It is characterized by comprising a first honeycomb plate that rectifies the air diffused by the diffusion portion and a second honeycomb plate that receives the airflow rectified by the first honeycomb plate and blows out a uniform air flow .

Further, the push-pull ventilation type local exhaust device according to the present invention includes a uniform flow blowout hood on the push side that blows out a uniform air flow, a local exhaust table on the pull side corresponding to the uniform flow blowout hood, and the like. in the push-pull ventilation type local exhaust device made up of, from said uniform flow blowout hood, and blown uniform air flow by only outside air primary treatment, the uniform flow blowout hood consists housing, the housing is, It has an air diffusion unit that diffuses air and a rectifying unit that rectifies the air diffused by the air diffusion unit, and the air diffusion unit collides with the supplied air to make the air a predetermined wind velocity distribution. The first honeycomb plate is composed of a resistance plate and a perforated plate that receives air having a predetermined wind velocity distribution by the resistance plate, and the rectifying portion rectifies the air diffused by the air diffusion portion. It is characterized by comprising a second honeycomb plate that receives an air flow rectified by one honeycomb plate and blows out a uniform air flow .

Further, the push-pull ventilation type local exhaust device according to the present invention is characterized in that when the primary treated outside air is blown out, the temperature of the primary treated outside air is set so as not to be higher than 1 ° C. with respect to room temperature. To do.

Further, the push-pull ventilation type local exhaust device according to the present invention is characterized in that one side of the first honeycomb plate and one side of the second honeycomb plate are arranged so as to overlap each other.

Further, in the push-pull ventilation type local exhaust device according to the present invention, the surface including each side of the first honeycomb plate and the second honeycomb plate that do not overlap is orthogonal to the first honeycomb plate. It is characterized by that.

Since the push-pull ventilation type local exhaust device 10 of the present invention is configured to blow out a uniform air flow by outside air that has not been subjected to temperature control processing from a uniform flow blowing hood, such a push of the present invention According to the pull-ventilation type local exhaust device 10, the outside air that has not been subjected to the temperature control process is mainly exhausted, so that energy efficiency can be improved and energy saving can be achieved.

Further, since the push-pull ventilation type local exhaust device 10 of the present invention is configured to blow out a uniform air flow only by the primary treated outside air from the uniform flow blowing hood, such a push-pull of the present invention is used. According to the ventilation type local exhaust device 10, the primary treated outside air is mainly exhausted, so that energy efficiency can be improved and energy saving can be achieved.

It is a figure which shows typically the schematic structure of the push-pull ventilation type local exhaust device 10 which concerns on embodiment of this invention. It is the schematic sectional drawing of the uniform flow blowing hood 100 of the push-pull ventilation type local exhaust device 10 which concerns on embodiment of this invention. It is a figure which looked at the uniform flow blowing hood 100 of the push-pull ventilation type local exhaust device 10 which concerns on embodiment of this invention from the bottom. It is a top view of the local exhaust table 200 of the push-pull ventilation type local exhaust device 10 which concerns on embodiment of this invention. It is a front view of the local exhaust table 200 of the push-pull ventilation type local exhaust device 10 which concerns on embodiment of this invention. It is a side view of the local exhaust table 200 of the push-pull ventilation type local exhaust device 10 which concerns on embodiment of this invention. It is a figure which shows the position of the measurement point used for the performance evaluation of the uniform flow blowing hood 100. It is a figure which shows the position of the measurement point used for the performance evaluation of the uniform flow blowing hood 100. It is a figure which shows the performance evaluation result of the uniform flow blowing hood 100. It is a figure which shows the uniform flow blowing hood 100 which changed the connection form of the 1st duct 105. It is a figure which shows the uniform flow blowing hood 100 which changed the connection form of the 1st duct 105. It is a figure which shows the performance evaluation result of the uniform flow blowing hood 100. It is a figure which shows the performance evaluation result of the uniform flow blowing hood 100. It is a figure which shows the position of the measurement point used for the performance evaluation of a local exhaust table 200. It is a figure which shows the position of the measurement point used for the performance evaluation of a local exhaust table 200. It is a figure which shows the performance evaluation result of the local exhaust table 200. It is a figure which shows the performance evaluation result of the local exhaust table 200. It is a figure which shows the relationship between the exhaust air volume and the error rate of the wind speed in a local exhaust table 200. It is a figure which shows the position of the measurement point used for the performance evaluation of the whole push-pull ventilation type local exhaust device 10 which concerns on embodiment of this invention. It is a figure which shows the performance evaluation result of the whole push-pull ventilation type local exhaust device 10 which concerns on embodiment of this invention. It is a figure which shows the performance evaluation result of the whole push-pull ventilation type local exhaust device 10 which concerns on embodiment of this invention. It is a figure which shows the performance evaluation result of the whole push-pull ventilation type local exhaust device 10 which concerns on embodiment of this invention. It is a figure which shows the performance evaluation result of the whole push-pull ventilation type local exhaust device 10 which concerns on embodiment of this invention. It is a photograph which took the state of the visualization experiment of the push-pull ventilation type local exhaust device 10 which concerns on embodiment of this invention. It is a figure explaining the definition of the measurement point used for the measurement of the wind speed by the 3D ultrasonic anemometer in the ventilation area. It is a figure which shows the YY cross-sectional view of the measurement result of the airflow characteristic in the vicinity of a ventilation area. It is a figure which shows the XZ sectional view of the measurement result of the airflow characteristic in the vicinity of a ventilation area. It is a figure which shows the performance evaluation result of the whole push-pull ventilation type local exhaust device 10 which concerns on embodiment of this invention. It is a figure which shows the performance evaluation result of the whole push-pull ventilation type local exhaust device 10 which concerns on embodiment of this invention. It is a figure which shows the relationship between the time from the start of introducing live outside air, and ΔT. This is a photograph of the change in smoke accompanying the change in ΔT. It is a photograph of the state of smoke at ΔT = 3.8. It is a figure which shows the outline of the experiment performed for evaluating the HCHO removal performance, and the measurement point at the time of the experiment. It is a perspective view which shows the measurement point at the time of the experiment performed for evaluating the HCHO removal performance. It is a figure which shows the result of the formaldehyde (HCHO) removal performance experiment. It is a flow chart of the enclosure type hood (Comparative Example 1), the conventional push pull (Comparative Example 2), and the present push pull (the present invention). It is a figure (1) explaining the comparison of the energy saving performance. It is a figure (2) explaining the comparison of energy saving performance.

Hereinafter, preferred embodiments of the push-pull ventilation type local exhaust system 10 according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram schematically showing a schematic configuration of a push-pull ventilation type local exhaust device 10 according to an embodiment of the present invention.

The push-pull ventilation type local exhaust device 10 according to the present invention is a device for performing local ventilation in order to prevent exposure when a worker handles an organic solvent such as formaldehyde in a research facility or a production factory. It consists of a push-side configuration that blows air to a location that handles organic solvents, etc., and a pull-side configuration that sucks air at that location.

In the push-pull ventilation type local exhaust device 10 according to the present invention, the former configuration is a uniform flow blowing hood 100 that blows out the taken-in outside air as a uniform air flow, and the latter configuration allows the operator to perform the work. It is a local exhaust table 200 that also serves as a workbench (table) for performing air and sucks air.

In the push-pull ventilation type local exhaust device 10 according to the present invention, the push-pull ventilation type local exhaust device that contributes to energy saving by minimizing the temperature control of the supply air on the push (uniform flow blowing hood 100) side is provided. Configured. More specifically, the push-pull ventilation type local exhaust device 10 according to the present invention is a ventilation device that introduces the outside air as it is without air conditioning as much as possible to form a push air flow.

The distance from the outlet 135 of the uniform flow outlet hood 100 to the suction port 204 of the local exhaust table 200 is about 1.3 m, and the wind speed is about 0.2 to 0.3 m / s, so the push airflow is 10. It is sucked from the suction port within seconds and has almost no effect on the surrounding room temperature and humidity. In addition, when using raw outside air, it is possible that workability may be affected by the introduction of cold air as a push air flow in winter. In such a case, by supplying the primary processed outside air, energy is consumed more than when the raw outside air is blown out, but energy is saved as compared with the conventional method.

The first blower fan 103 in the push-pull ventilation type local exhaust device 10 according to the present invention sucks outside air from an intake port (not shown) and supplies the outside air to the uniform flow blowing hood 100 through the first duct 105. To do. At this time, the temperature control process of the outside air is basically not performed. In the uniform flow blowing hood 100, the outside air that has not been temperature-controlled is rectified, and a uniform air flow is blown vertically downward from the outlet 135 of the uniform flow blowing hood 100.

Further, a suction port 204 is provided on the upper surface of the local exhaust table 200. The suction port 204 is connected to the second blower fan 237, and when the second blower fan 237 operates, the air sucked from the suction port 204 is exhausted through the second duct 235 and the like (not shown). It is exhausted from the mouth to the outside.

Since the air flow from the outlet 135 of the uniform flow outlet hood 100 to the suction port 204 of the local exhaust table 200 is about 10 seconds, the outside air that has not been temperature-controlled is blown out from the uniform flow outlet hood 100. However, there is almost no effect on indoor temperature and humidity.

In the push-pull ventilation type local exhaust device 10 according to the present invention, the live outside air is blown out from the uniform flow blowing hood 100 with a uniform wind speed distribution, and the local exhaust table is used so as not to diffuse harmful substances in the ventilation area to the surroundings. It is supplemented with 200, and is sucked and exhausted. The push-pull ventilation type local exhaust device 10 according to the present invention satisfies the Organic Solvent Poisoning Prevention Regulations (hereinafter, “Organic Regulations”).

As described above, according to the push-pull ventilation type local exhaust device 10 of the present invention, the outside air that has not been subjected to the temperature control process is mainly exhausted, so that energy efficiency can be improved and energy saving can be achieved.

If there is an effect on the operator, the uniform flow blowing hood 100 can supply the outside air that has undergone only the primary treatment, for example, with the total heat exchanger unit, to generate more energy than when blowing out the raw outside air. Although it consumes, it saves energy compared to the conventional method.

Next, the uniform flow blowing hood 100 of the push-pull ventilation type local exhaust device 10 configured as described above will be described in more detail.

FIG. 2 is a schematic cross-sectional view of the uniform flow blowing hood 100 of the push-pull ventilation type local exhaust device 10 according to the embodiment of the present invention. Further, FIG. 3 is a view of the uniform flow blowing hood 100 of the push-pull ventilation type local exhaust device 10 according to the embodiment of the present invention as viewed from below. The outline of the housing 110 and the outlet 135 and their dimensions are shown in FIGS. 2 and 3. Further, the appearance seen from the 135 side of the outlet is shown in FIG.

The uniform flow blowing hood 100 of the push-pull ventilation type local exhaust device 10 of the present invention has a housing 110 in which an air diffusion unit 120 and a rectifying unit 130 are housed.

The outside air supplied to the air diffusion portion 120 of the uniform flow blowout hood 100 via the first duct 105 collides with the resistance plate 123, is diffused to an appropriate velocity distribution by the perforated plate 125 made of punching metal or the like, and is rectified. It is introduced into the unit 130.

Inside the housing 110 of the rectifying unit 130, the first honeycomb plate 131 tilted so that the ∠PQR connecting the points P, Q, and R in FIG. 2 is 90 ° is rectified in the blowing direction. A second second honeycomb plate 132 for this purpose is provided.

That is, in the rectifying section 130 of the uniform flow blowing hood 100, one side of the first honeycomb plate 131 and one side of the second honeycomb plate 132 are arranged so as to overlap each other. The overlapping sides are the sides that pass through P on the paper surface and are perpendicular to the paper surface.

Further, each of the non-overlapping sides of the first honeycomb plate 131 and the second honeycomb plate 132 (the side that passes through Q on the paper surface and is perpendicular to the paper surface, and the side that passes through R on the paper surface and is perpendicular to the paper surface) is included. The virtual surface and the first honeycomb plate 131 are orthogonal to each other.

The air whose wind direction is changed by the first first honeycomb plate 131 passes through the second second honeycomb plate 132 and is blown out as a uniform flow from the outlet 135 on one side surface of the housing 110. ..

In order to rectify air by a honeycomb plate such as the first honeycomb plate 131 or the second honeycomb plate 132, it is necessary to pay attention to the relationship between the honeycomb cell size and the thickness of the honeycomb plate, and the thickness of the honeycomb plate is 3 mm. The rectifying effect can be achieved by ensuring the thickness of the honeycomb plate to a certain level or more according to the cell size of the honeycomb plate, such as setting the thickness to 15 mm or more, or setting the thickness of the honeycomb plate to 100 mm or more for a cell size of 9 mm. You can expect it.

The role of the resistance plate 123 is to eliminate the difference in the wind speed distribution of the introduced airflow due to the difference in the connection direction of the duct to the housing 110. As a result, in the push-pull ventilation type local exhaust device 10 according to the present invention, the method of connecting the duct to the housing 110 does not affect the formation of a uniform flow. Further, the role of the perforated plate 125 is to change the airflow having a predetermined wind speed distribution by the resistance plate 123 into a uniform airflow to some extent, and to blow the airflow to the honeycomb plate in the subsequent stage.

Next, the local exhaust table 200 of the push-pull ventilation type local exhaust device 10 will be described in more detail. FIG. 4 is a plan view of the local exhaust table 200 of the push-pull ventilation type local exhaust device 10 according to the embodiment of the present invention. Further, FIG. 5 is a front view of the local exhaust table 200 of the push-pull ventilation type local exhaust device 10 according to the embodiment of the present invention. Further, FIG. 6 is a side view of the local exhaust table 200 of the push-pull ventilation type local exhaust device 10 according to the embodiment of the present invention, and shows a state in which an operator is performing work on the local exhaust table 200. The outline of the dimensions of the local exhaust table 200 of the push-pull ventilation type local exhaust device 10 of the present invention is shown in FIGS. 4 and 5.

The top surface of the local exhaust table 200 of the push-pull ventilation type local exhaust device 10 according to the present invention is a work surface 202 on which an operator handles organic solvents and the like. Further, the local exhaust table 200 has a leg portion 206 that supports the work surface 202, and a caster 208 is further provided at the installation side end portion of the leg portion 206.

A suction port 204 is provided on the work surface 202, which is the top surface of the local exhaust table 200. The uniform flow outlet hood 100 and the local exhaust table 200 are arranged so that the projection of the outlet 135 of the uniform flow outlet hood 100 vertically downward overlaps with the suction port 204 of the local exhaust table 200. Will be installed.

The uniform downward flow air blown out from the outlet 135 (400 × 1000 mm) of the uniform flow outlet hood 100 is sucked by the suction port 204 having the same shape on the work surface 202.

In the local exhaust table 200 of the push-pull ventilation type local exhaust device 10 according to the present invention, a perforated plate 210 made of punching metal or the like is sucked into the suction port 204 so as to have a uniform wind speed distribution as in the outlet 135. It is laid at the mouth 204.

The local exhaust table 200 has a chamber 215 having one side surface having a slope shape so that the depth gradually increases with respect to the duct connection direction, and the chamber 215 is connected to the second duct 235. ing. Further, since the chamber 215 has the above-mentioned shape, the operator can store the legs under the local exhaust table 200 when seated as shown in FIG.

The performance of each of the uniform flow blowing hood 100 and the local exhaust table 200 of the push-pull ventilation type local exhaust device 10 according to the present invention configured as described above was examined.

The punching metal used for the push-pull ventilation type local exhaust device 10 has a hole diameter of 4.5 mm, a center pitch of 8.0 mm, an aperture ratio of 28.7%, and a 60 ° zigzag, and both honeycomb plates have a cell size of 3 mm. It is made of hard vinyl chloride with a thickness of 40 mm.

The uniform flow blowout hood of the push-pull ventilation type local exhaust device 10 according to the present invention is described in "Factory Ventilation" published in 1982 (published by Taro Hayashi, Air Conditioning and Sanitary Engineering Society). If the accuracy of the uniformity is increased to within ± 20%, a uniform flow will be obtained and the cross section will be continuous. ”The performance was verified based on the description.

Further, the first honeycomb plate 131 and the second honeycomb plate 132 constituting the uniform flow blowing hood 100 used in the performance evaluation are both having a cell size of 3 mm and a thickness of 40 mm. The dimensions of the outlet of the uniform flow outlet hood 100 used in the performance evaluation are as shown in FIG. The amount of air blown to the uniform flow blowing hood 100 is about 432 m ³ / h, and this amount of air blows a uniform flow from the uniform flow blowing hood 100 at about 0.3 m / sec.
The suction port dimensions of the local exhaust table 200 used in the performance evaluation are as shown in FIG. The displacement from the local exhaust table 200 is about 500 m ³ / h, and due to this displacement, it is about 0.35 m / sec to the local exhaust table 200, which is slightly different from the uniform flow air from the uniform flow outlet hood 100. The surrounding air is taken in and then exhausted from the exhaust port (not shown).

The temperature of the air supplied from the room and the uniform flow blowing hood 100 at the time of measurement is about 25 ° C.

7 and 8 are diagrams showing the positions of measurement points used for the performance evaluation of the uniform flow blowing hood 100. As shown in FIG. 7, all the measurement points are provided at locations 20 mm below the outlet 135 of the uniform flow outlet hood 100. Further, FIG. 8 is a view of the outlet 135 of the uniform flow outlet hood 100 as viewed from below. The outlet 135 is divided into 3 × 9 rectangular sections, and measurement points are arranged in the center of each rectangular section. ing. In order to distinguish each measurement point, the sections on the short side of the outlet 135 are named A to C, and the sections on the long side of the outlet 135 are named 1-9. By defining in this way, a total of 27 measurement points from A1 to C9 are used in the performance evaluation.

In addition, A to C in the rectangular section are referred to as vertical coordinates, and 1 to 9 in the rectangular section are referred to as horizontal coordinates.

Further, a 90 ° elbow duct as the first duct 105 is connected to the uniform flow blowing hood 100 so that air is blown from below as shown in FIG. 7, and blown by the first blower fan 103 to be uniform. The wind speed of the blown air flow formed by the flow blown hood 100 was measured.

Heat ray anemometer (Climomaster anemometer: Nippon Canomax product, resolution 0.01 m / sec, measurement accuracy ± (3% of indicated value + 0.1 m / sec)) at a total of 27 measurement points explained above. Was measured 10 times for 1 sec at each measurement point, and the average was taken as the wind speed at each measurement point.

The results are shown in FIG. The horizontal axis is the abscissa 1 to 9 of the measurement point shown in FIG. 7, the legend is the abscissa A to C, and the vertical first axis is defined by the following equation (1) based on the description of the forest. The error rate α _n of the wind speed at each measurement point, and the vertical second axis is the average wind speed V _n at each measurement point. In the following equation (1), V _Ave. Represents the average of the wind speeds V _{n at} 27 points (see equation (2) below). V _{1 to} V ₂₇ are wind speeds at each of a total of 27 measurement points from A1 to C9. Hereinafter, in the present specification, the same definitions are used for the average wind speed and the error rate.

According to the performance evaluation of the uniform flow blowout hood 100 as described above, the variation is -7.9 to + 8.5%, and the uniform flow (average wind speed 0.30 m / sec) with sufficient accuracy directly under the blowout port 135. Was confirmed to be formed.

Further, assuming practical use, the direction of connection of the elbow duct used as the first duct 105 is, as shown in FIG. 10 or FIG. 11, blowing from the lateral direction or blowing from above, respectively. As described above, the connection was reconnected, and the same measurement was performed again under each connection condition. The performance evaluation results of the uniform flow blowing hood 100 in those cases are shown in FIGS. 12 and 13.

The variation in the wind speed distribution directly below the outlet 135 of the uniform flow outlet hood 100 is −8.3 to + 10.7% in the case of the connection shown in FIG. 10, and −6. In the case of the connection shown in FIG. It was 1 to + 10.1%.

As a result, by changing the connection direction of the duct connected to the uniform flow blowing hood 100, even if the wind speed distribution of the air flowing into the uniform flow blowing hood 100 changes, the uniform flow blowing hood 100 has a uniform flow. It was confirmed that the formation was possible. That is, even if the wind speed distribution at the time of introduction into the chamber changes due to the change in the connection direction of the duct, the inflow air is rectified by passing through the resistance plate, punching metal, and honeycomb plate in the subsequent stage, and the outlet 135 It was confirmed that it was blown out as a uniform flow. Therefore, the uniform flow blowing hood 100 according to the present invention has high versatility for the duct work in the actual design. Based on this result, in the subsequent studies, unless otherwise specified, the duct is connected to the uniform flow blowing hood 100 from below.

Next, the performance of the local exhaust table 200 of the push-pull ventilation type local exhaust device 10 according to the present invention was evaluated. 14 and 15 are diagrams showing the positions of measurement points used for the performance evaluation of the local exhaust table 200.

For the local exhaust table 200, a full-scale model made of SUS was manufactured. The laid punching metal has a hole diameter of 2.3 mm, a center pitch of 4.0 mm, an aperture ratio of 30%, and a 60 ° staggered shape. Exhaust from the local exhaust table 200 with the second blower fan 237 at an air volume of about 490 m ³ / h, and measure the wind speed distribution on a plane 20 mm directly above the suction port 204 surface at the measurement point shown in FIG. 14 by the same method as the outlet 135. did.

As shown in FIG. 15, all the measurement points are provided at locations 20 mm above the suction port 204 of the local exhaust table 200. Further, FIG. 14 is a view of the suction port 204 of the local exhaust table 200 as viewed from above, but the suction port 204 is divided into 3 × 9 rectangular sections as in the case of the outlet 135 of the uniform flow outlet hood 100. However, the measurement points are arranged in the center of each rectangular section. In order to distinguish each measurement point, the sections on the short side of the suction port 204 are named A to C, and the sections on the long side of the suction port 204 are named 1-9. By defining in this way, a total of 27 measurement points from A1 to C9 are used in the performance evaluation.

The definition of the rectangular section as described above is also used when evaluating the performance of the entire push-pull ventilation type local exhaust device 10 according to the present invention.

At the measurement points shown in FIGS. 14 and 15 as described above, the wind speed distribution directly above the suction port 204 of the local exhaust table 200 was measured in the same manner as in the case of the outlet 135.

An example of the result is shown in FIGS. 16 and 17. The definitions of the vertical axis and the horizontal axis in FIG. 17 are the same as in the previous example.

The above-mentioned error rate of the wind speed was −7.2 to + 10.2%, and the same wind speed (average 0.34 m / sec) was confirmed regardless of the position of the measurement point. As shown in FIGS. 16 and 17, the wind speed is about the same regardless of the measurement point, and according to the local exhaust table 200 according to the present invention, the wind speed descends from the uniform flow blowing hood 100 on the upper part of the work surface 202. It is considered that the incoming air can be sucked uniformly.

Further, when the same measurement was performed by increasing the exhaust air volume to 1120 m ³ / h, as shown in FIG. 18, no significant change was observed in the error rate of the suction wind speed, and the suction wind speed was uniform by the local exhaust table 200. It was confirmed that the property does not depend on the exhaust air volume in the measurement range. FIG. 18 is a diagram showing the relationship between the exhaust air volume and the error rate of the wind speed in the local exhaust table 200.

Based on the above, the wind speed of the entire push-pull ventilation type local exhaust device 10 according to the present invention was measured with both the uniform flow blowing hood 100 and the local exhaust table 200 actually operating. The setup at this time is shown in FIG.

The position of the rectangular section of the measurement point is the same as in FIG. In order for the push-pull ventilation type local exhaust device 10 according to the present invention to be approved as a local exhaust device when handling an organic solvent, it is necessary to satisfy the following organic rules.

"(Organic law)
The capture surface is divided into six or more equal-area quadrilaterals with a side of 2 m or less, and the wind speed is measured at the center of the quadrilateral with no work object in the ventilation area. When the measured wind speed meets the following conditions, it is recognized as a push-pull type local exhaust system. The trapping surface refers to a plane that passes through the vapor emission source of the organic solvent at the position farthest from the suction hood and is perpendicular to the direction of the air flow.
(1) The average wind speed is 0.2 m / sec or more.
(2) The wind speed at each measurement point shall be ± 50% (0.5 times or more, less than 1.5 times) of the average wind speed.

(That is, the error rate α _{n of the} wind speed defined by the equation (1) must be within ± 50%.)
(3) All airflow at the boundary between the ventilation area and the external area flows in the suction direction. 』\
The ventilation area of the push-pull ventilation type local exhaust device 10 can be defined as a space between the outlet 135 of the uniform flow outlet hood 100 and the suction port 204 of the local exhaust table 200.

As shown in FIG. 19, a plane of 1000 × 400 mm located at a height of 200 mm from the work surface 202 of the local exhaust table 200 was set as the capture surface defined by the above organic law.

The measuring method and the air volume on the blowing side and the suction side are as described above. The planar position of the measurement point is the same as that in FIG. 14, and the capture surface is divided into 27 quadrilaterals having a size of about 111 × 133 mm, and the measurement is performed at 27 points in the center thereof. The connection direction of the duct was the connection condition from the downward direction and the horizontal direction (horizontal direction).

The connection direction of the duct was the condition shown in FIGS. 7 and 10. The performance evaluation results of the entire push-pull ventilation type local exhaust device 10 are shown in FIGS. 20 and 21 for the duct connection condition of FIG. 7, and in FIGS. 22 and 23 for the duct connection condition of FIG.

The average wind speed at each measurement point is 0.22 m / sec for the duct connection pattern for blowing from below and 0.25 m / sec for the duct connection pattern for blowing from the lateral direction, which is a reference of the organic law. It exceeded the wind speed of 0.2 m / sec.

In addition, the error rate of the wind speed at each measurement point is -37.7 to + 29.0% for the duct connection pattern that blows from below, and the duct connection pattern that blows from the side at 27 measurement points. It is -24.2- + 19.6%, which satisfies the standard of organic law (variation ± 50% at 6 or more measurement points) with a sufficient margin.

Regarding the above (3) of the organic law, in order to actually confirm the state of the airflow in the ventilation area in the push-pull ventilation type local exhaust device 10, the airflow was visualized with smoke of oil mist. FIG. 24 is a photograph of a visualization experiment of the push-pull ventilation type local exhaust device 10 according to the embodiment of the present invention. FIG. 24 (A) shows the case where the oil mist exhaust port is arranged on the uniform flow outlet hood 100 side, and FIG. 24 (B) shows the case where the oil mist exhaust port is arranged on the local exhaust table 200 side. FIG. 24C shows a case where an oil mist exhaust port is arranged substantially in the middle between the uniform flow outlet hood 100 and the local exhaust table 200 at the boundary of the ventilation area.

In the visualization experiment, the air volume on the outlet 135 side of the uniform flow outlet hood 100 and the air volume on the suction port 204 side of the local exhaust table 200 is the same as that at the time of the performance evaluation of the push-pull ventilation type local exhaust device 10. At the time of the experiment, the ventilation of the laboratory itself was stopped.

First, when smoke was generated in the vicinity of the outlet 135, it was confirmed that the smoke moved to the suction port 204 of the local exhaust table 200 without being significantly disturbed (FIG. 24 (A)). Further, when smoke was generated at both ends in the longitudinal direction of the ventilation area, it was visually recognized that the airflow at the boundary between the ventilation area and the outside was flowing in the direction of the suction port 204 (FIG. 24 (C)). From the above, together with the results of the performance evaluation of the push-pull ventilation type local exhaust device 10, it was confirmed that the push-pull ventilation type local exhaust device 10 according to the present invention has a performance sufficiently satisfying the organic law. ..

As described above, the push-pull ventilation type local exhaust device 10 of the present invention is configured to blow out a uniform air flow by outside air that has not been subjected to temperature control processing from the uniform flow blowing hood 100. According to the push-pull ventilation type local exhaust device 10 of the present invention, the outside air that has not been subjected to the temperature control process is mainly exhausted, so that energy efficiency can be improved and energy saving can be achieved.

Further, since the push-pull ventilation type local exhaust device 10 of the present invention is configured to blow out a uniform air flow only by the primary treated outside air from the uniform flow blowing hood 100, such a push of the present invention is made. According to the pull ventilation type local exhaust device 10, the primary treated outside air is mainly exhausted, so that energy efficiency can be improved and energy saving can be achieved.

Next, the measurement result of the wind speed by the three-dimensional ultrasonic anemometer in the ventilation area of the push-pull ventilation type local exhaust device 10 according to the present invention will be described.

In order to grasp the airflow characteristics in the ventilation area in more detail, measurements using a three-dimensional ultrasonic anemometer (WA-590: KAIJO) were also performed. FIG. 25 is a diagram for explaining the definition of the measurement point used for measuring the wind speed by the three-dimensional ultrasonic anemometer in the ventilation area, and FIG. 25 (A) is a top view of the local exhaust table 200, FIG. 25 (A). B) is a side view of the uniform flow blowing hood 100 and the local exhaust table 200.

As shown in FIG. 25, the measurement points were arranged in a grid pattern, and not only the ventilation area but also the turbulence of the surrounding airflow was examined. The conditions such as the air volume at the time of measurement are all the same as those at the time of performance evaluation of the push-pull ventilation type local exhaust device 10. At the time of measurement, the ventilation of the laboratory itself was stopped.

The results are shown in FIG. 26 for a YY cross section and FIG. 27 for an XX cross section. The direction of the arrow represents the wind direction, the length represents the wind speed, and the radius of the circle represents the strength of the three-dimensional turbulence. From this, it was confirmed that according to the push-pull ventilation type local exhaust device 10 according to the present invention, a vertically downward airflow is formed in the ventilation area, turbulence is small, and an intended uniform flow is formed.

Further, the airflow outside the ventilation area does not form a downward flow, the wind speed is small and stable, and the airflow by the push-pull ventilation type local exhaust device 10 according to the present invention does not significantly affect the surrounding airflow. Can also be confirmed (see FIG. 26 (X = 1, 7) and FIG. 27 (Y = 1, 2, 6)). It was also clarified that both the YZ cross section and the XZ cross section are more stable with less turbulence as the airflow near the outlet 135 and at the center.

Next, in the push-pull ventilation type local exhaust device 10 according to the present invention, the airflow behavior in the ventilation area when the push airflow blown out from the uniform flow blowing hood 100 is at a high temperature was examined.

The push-pull ventilation type local exhaust device 10 according to the present invention is premised on using live outside air, but in winter, the low outside air temperature supplied as push airflow adversely affects the workability of the operator. It is necessary to raise the push airflow to an appropriate temperature because of the possibility.

On the other hand, when the outside air becomes hot in summer and the raw outside air is supplied as a push air flow, it is assumed that the room temperature T _I is lower than the air temperature T _S. Under such circumstances, buoyancy due to the temperature difference acts on the push airflow.

Since the push-pull ventilation type local exhaust device 10 according to the present invention blows down the push airflow from the upper outlet 135 to the lower suction port 204, the flow is obstructed by buoyancy at high temperatures, and the wind speed is appropriate in the ventilation area. It is possible that the distribution does not occur. Therefore, the push-pull ventilation type local exhaust device 10 according to the present invention, the temperature T _S and room temperature T _I of the balloon airflow were again performance evaluation under the condition of T _S> T _I. For the sake of simplicity, the evaluation method was visualization by smoke.

Since the buoyancy is determined by the temperature difference between the target air and the surrounding air ΔT = T _{S −} T _I , we focused on ΔT in this measurement and verified its effect. Temperature, experiment room temperature T _I, the outside air temperature T _O
, (20 mm from the outlet 135 side) balloon airflow temperature T _S, (200 mm from the suction port 204 side) capture surface airflow temperature was measured five points suction airflow temperature (20 mm from the suction surface). In this specification, utilizing particular experiment room temperature T _I, the outside air temperature T _O, the value of the balloon airflow temperature T _S to evaluate the performance of the following devices.

First, as a preliminary study, as in the past, the room air was blown to the push side by the first blower fan 103, and the temperature at each point was confirmed. At this time, suction was also performed at the local exhaust table 200. Each air volume is the same as the previous condition. As a result, the temperature of the indoor air that passed through the first blower fan 103 increased, and the result showed that the air was blown out from the push side (uniform flow blowing hood 100) in a state of about 1 ° C. higher. Therefore, it was clarified that all the results so far were the airflow characteristics by the push-pull ventilation type local exhaust device 10 under the condition of ΔT = 1 ° C.

Next, the suction port of the first blower fan 103 was opened to the outside, and the outside air was blown to the uniform flow blowing hood 100 at about 428 m ³ / h, which was almost the same as when the indoor air was introduced. The error rates of the wind speeds directly below the outlet 135 (FIG. 28) and directly above the suction port 204 (FIG. 29) were also measured again, and it was confirmed that they were about the same as the previous examination as shown in FIGS. 28 and 29.

FIG. 30 shows the relationship between ΔT and the time since the suction duct of the first blower fan 103 was opened to the outside air and the raw outside air was introduced. On the day of the experiment, the outside air was about 27.9 ° C.
The room temperature was about 21.9 ° C, and a difference of about 6.0 ° C was observed. From FIG. 30, it was confirmed that the introduction of the outside air into the outlet 135 caused the outlet temperature to rise immediately, and the difference ΔT from the room temperature became a steady state at about 3.8 ° C. 10 minutes after the introduction.

By introducing it into the uniform flow blowing hood 100 as described above, ΔT was changed with time, and the behavior of the air flow in the ventilation area during that period was observed by visualization by smoke. The situation is shown in FIGS. 31 and 32. The time shown in FIG. 31 corresponds to the horizontal axis in FIG.

First of all, it was confirmed again that smoke was inhaled under the above conditions (1.0 ° C difference) as in the result of the visualization experiment shown in FIG. 24. Although the wind speed began to drop around 200 to 400 mm on the desk surface of the local exhaust table 200 due to the difference of 1.5 ° C., it was observed that all the smoke flowed to the suction port 204.

At a difference of 2.0 ° C, smoke began to leak in the lateral direction of the ventilation area (before and after the paper), and it was observed that about half of the smoke leaked to the suction port 204 and the other half leaked to the outside of the ventilation area. At a difference of 2.5 ° C, smoke hardly flowed to the suction port 204, and most of them leaked to the outside. At this time, the lowest reaching position of the smoke was about 300 mm from the desk surface of the local exhaust table 200. With a difference of 3.0 ° C, the lowest reaching position was about 500 mm from the desk surface of the local exhaust table 200, and with a difference of 3.5 ° C, it was about 600 to 700 mm, resulting in no smoke being sucked.

Based on the above, it was judged that the use of the push-pull ventilation type local exhaust device 10 according to the present invention at ΔT> 1 ° C. was not appropriate, and in the subsequent studies, it was decided to blow the indoor air with a fan as before. That is, the result is about ΔT = 1 ° C. Further, from the above examination results, in the push-pull ventilation type local exhaust device 10 according to the present invention, when the primary treated outside air is blown out from the uniform flow blowing hood 100, the temperature of the primary treated outside air is set to room temperature. Set so that the temperature does not rise above 1 ° C.

Next, the removal performance of the organic solvent by the push-pull ventilation type local exhaust device 10 according to the present invention was evaluated. In the following removal performance evaluation, formaldehyde (HCHO) was used as the organic solvent.

In order to examine the HCHO removal performance of the push-pull ventilation type local exhaust device 10 according to the present invention, HCHO gas is actually generated in the ventilation area, the gas concentration near the work area is measured, and the push-pull ventilation type local exhaust device 10 is used. Comparison was made between 10 operating hours and non-operating hours.

The outline of the experiment conducted for evaluating the HCHO removal performance of the push-pull ventilation type local exhaust device 10 will be described below.

The outline of the experiment and the measurement points are shown in FIGS. 33 and 34. FIG. 33 is a diagram showing an outline of an experiment conducted for evaluating HCHO removal performance and measurement points during the experiment. FIG. 33 (A) is a top view of the local exhaust table 200, and FIG. 33 (B) is a side view of the uniform flow blowing hood 100 and the local exhaust table 200. Further, FIG. 34 is a perspective view showing measurement points during an experiment conducted for evaluating the HCHO removal performance. Points (1) to (20) are measurement points.

In order to generate HCHO gas, 300 ml of a 10% formalin solution was placed in a glass petri dish and installed at the center of the suction port 204 of the local exhaust table 200. Since the room temperature at the time of the experiment was as low as 16 to 18 ° C., it was necessary to promote the generation of gas in order to reproduce the actual usage environment. Therefore, a petri dish containing a formalin solution was placed on a hot plate and the experiment was conducted while raising the temperature to 25 ° C. During the experiment, the temperature of the formalin solution in the petri dish was constant at 25 ° C.

Assuming actual work, the measurement points were set to a total of 20 points near the work area in FIGS. 33 and 34. The points (1) to (10) are located on the center line in the longitudinal direction of the suction port 204, and the points (11) to (19) are located on the left end of the suction port 204. In addition, in order to examine the diffusion state of HCHO outside the ventilation area, a point (10) behind the operator and a measurement point (20) around the ventilation device were set and set.

For the measurement, HCHO in the air was collected by DNPH (2,4-dinitrophenylhydrazine) at a flow rate of 1.0 L / min for 30 minutes at each point, and then eluted with an acetonitrile solution to perform a high performance liquid chromatograph (LC System). : Japan spectroscopy) was used to analyze and calculate the concentration.

For comparison, measurements were taken when the device was in operation and when it was not in operation. The air volume of air supply and exhaust is the same as the previous condition. At this time, the ventilation of the laboratory itself was stopped. The room temperature at the time of measurement was about 17.6 ° C. during operation and about 16.9 ° C. during non-operation.
FIG. 35 shows the HCHO concentration measured at each point during operation and non-operation of the push-pull ventilation type local exhaust device 10 according to the present invention, and the HCHO removal rate by operating the main ventilation device. When the push-pull ventilation type local exhaust device 10 according to the present invention was not in operation, a high concentration of HCHO was measured, with a maximum point (8) of 4.30 ppm and an average value of 0.843 ppm. 0.239 ppm was also measured at the point (7) near the respiratory range, which exceeded the control concentration of 0.1 ppm set in the special rule (regulation for prevention of chemical substance disorders). On the other hand, when the push-pull ventilation type local exhaust device 10 according to the present invention is in operation, the maximum point (2) is 0.0332 ppm and the average value is 0.0166 ppm, which are about 2 orders of lower concentration than in operation. The concentration was well below 0.1 ppm.
At the measurement points (10) and (20) around the work area, 0.225 ppm was measured at the point (10) and 0.162 ppm at the point (20) when not in operation, and HCHO emission was confirmed outside the ventilation area. Was done. On the other hand, during operation, the concentration was 0.0214 ppm at the point (10) and 0.0151 ppm at the point (20), confirming that the concentration was one order or more low.
The average HCHO removal rate at each measurement point was 98% or more, confirming high removal performance. As a result of measuring the formaldehyde concentration blank in the laboratory under the condition of room temperature of 19.3 ° C., it was 0.009 ppm, and if this device was not operated, formaldehyde would certainly leak out of the ventilation area, and this device would be operated. It was confirmed that it was removed properly.

From the above, it was confirmed that by operating the push-pull ventilation type local exhaust device 10 according to the present invention, HCHO generated in the ventilation area can be appropriately sucked and exhausted without leaking to the surroundings, and its effectiveness is shown. Was done.

Next, the evaluation of the energy-saving performance of the push-pull ventilation type local exhaust device 10 according to the present invention will be described.

In order to verify the energy-saving performance of the push-pull ventilation type local exhaust device 10 according to the present invention, it is assumed that the enclosed hood (Comparative Example 1), the conventional push-pull (Comparative Example 2), and the present push-pull (the present invention) are used. , The amount of heating and cooling required for air conditioning of the supply outside air required to keep the room pressure at ± 0 was compared and examined. The amount of circulating air required for indoor air conditioning, the amount of outside air required for ventilation, fan power, etc. were excluded from the calculation. FIG. 36 shows a flow chart of three methods compared and examined.

The room where the exhaust system was installed was cooled annually and set at 23 ° C. The outside air was controlled to 18 ° C throughout the year by a circulation air conditioner. Further, the push-pull ventilation type local exhaust device 10 according to the present invention is characterized by using raw outside air as the push side supply air, but when the outside air falls below 15 ° C., an external air conditioner is used in consideration of workability. It was decided to heat to 15 ° C. and blow out. In addition, since the performance expected from the previous study that the difference ΔT between the room temperature and the blowout temperature is larger than 1 ° C is not exhibited, it is considered on the safer side and cooled to 23 ° C when the outside air temperature exceeds the room temperature of 23 ° C. It was assumed that it would blow out.

In addition, the shape of the air supply / exhaust port of each method was the same, and the wind speed was set according to the rules of each method. First, the exhaust / supply air volume in the push-pull (the present invention) is the same as the previous experimental conditions, and the outside air is blown at 432 m ³ / h (face wind speed 0.30 m / sec) with the uniform flow blowout hood 100. Supply, local exhaust table 200 to 490 m ³ / h (face wind speed 0.34 m / sec) was used as exhaust. Therefore, it was decided to air-condition the outside air of 58 m ³ / h at 18 ° C and supply it indoors. In the enclosed hood (Comparative Example 1), since the surface wind speed of the exhaust hood is set to 0.4 m / sec, which is the control wind speed of the organic law, the supply / exhaust amount is 576 m ³ / h. In the conventional push-pull (Comparative Example 2), the air supply / exhaust air volume is set to 490 m ³ / h with the same performance as that of the present invention.

Assuming that one exhaust system for comparison was operated in Tokyo for one year, the operating time was set to 10 hours a day, 240 days a year, and therefore 2400 hours a year. In addition, using the annual meteorological data of Tokyo, the amount of heat required to air-condition 1 m ³ of the outside air to a predetermined temperature was calculated every hour, and the annual calorific value basic unit was created. The amount of heat can be calculated by multiplying this basic unit by the amount of air.

37 and 38 show the setting conditions, the calculated heating / cooling heat quantity, and the heat quantity reducing effect according to the present invention. From this result, the present push-pull (the present invention) is 61% cooler than the enclosed hood (Comparative Example 1), 43% warmer, 55% cooler than the conventional push-pull (Comparative Example 2), and more heated. It was confirmed that the calorific value reduction effect can be expected by 33%.

As described above, the push-pull ventilation type local exhaust device 10 of the present invention is configured to blow out uniform flow air from the outside air that has not been subjected to temperature control processing from the uniform flow blowout hood. According to the push-pull ventilation type local exhaust device 10, the outside air that has not been subjected to the temperature control process is mainly exhausted, so that energy efficiency can be improved and energy saving can be achieved.

Further, since the push-pull ventilation type local exhaust device 10 of the present invention is configured to blow out a uniform air flow only by the primary treated outside air from the uniform flow blowing hood, such a push-pull of the present invention is used. According to the ventilation type local exhaust device 10, the primary treated outside air is mainly exhausted, so that energy efficiency can be improved and energy saving can be achieved.

10 ... Push-pull ventilation type local exhaust device 100 ... Uniform flow blowout hood 103 ... First blower fan 105 ... First duct 110 ... Housing 120 ... Air diffuser 123 ...・ ・ Resistance plate 125 ・ ・ ・ Perforated plate 130 ・ ・ ・ Rectifying part 131 ・ ・ ・ First honeycomb plate 132 ・ ・ ・ Second honeycomb plate 135 ・ ・ ・ Outlet 200 ・ ・ ・ Local exhaust table 202 ・ ・ ・ Work Surface 204 ... Suction port 206 ... Leg 208 ... Caster 210 ... Perforated plate 215 ... Chamber 235 ... Second duct (suction duct)
237 ... 2nd blower fan

Claims (5)

In a push-pull ventilation type local exhaust device including a uniform flow blowing hood on the push side for blowing out a uniform air flow and a local exhaust table on the pull side corresponding to the uniform flow blowing hood.
Wherein the uniform flow blowout hood, and blown uniform air flow by the outside air that has not been temperature adjustment process,
The uniform flow blowing hood is composed of a housing, and the inside of the housing has an air diffusion unit that diffuses air and a rectifying unit that rectifies the air diffused by the air diffusion unit.
The air diffuser
A resistor plate that collides with the supplied air and makes the air have a predetermined wind speed distribution,
It is composed of a perforated plate that receives air having a predetermined wind speed distribution by the resistance plate.
The rectifying unit
It is characterized by comprising a first honeycomb plate that rectifies the air diffused by the air diffusion portion and a second honeycomb plate that receives the airflow rectified by the first honeycomb plate and blows out a uniform air flow. Push-pull ventilation type local exhaust system. In a push-pull ventilation type local exhaust device including a uniform flow blowout hood on the push side for blowing out a uniform air flow and a local exhaust table on the pull side corresponding to the uniform flow blowout hood.
Wherein the uniform flow blowout hood, and blown uniform air flow by only outside air primary treatment,
The uniform flow blowing hood is composed of a housing, and the inside of the housing has an air diffusion unit that diffuses air and a rectifying unit that rectifies the air diffused by the air diffusion unit.
The air diffuser
A resistor plate that collides with the supplied air and makes the air have a predetermined wind speed distribution,
It is composed of a perforated plate that receives air having a predetermined wind speed distribution by the resistance plate.
The rectifying unit
It is characterized by comprising a first honeycomb plate that rectifies the air diffused by the air diffusion portion and a second honeycomb plate that receives the airflow rectified by the first honeycomb plate and blows out a uniform air flow. Push-pull ventilation type local exhaust system. The push-pull ventilation type local exhaust device according to claim 2, wherein when the primary treated outside air is blown out, the temperature of the primary treated outside air is set so as not to be higher than 1 ° C. with respect to room temperature. The push-pull ventilation according to any one of claims 1 to 3 , wherein one side of the first honeycomb plate and one side of the second honeycomb plate are arranged so as to overlap each other. Type local exhaust system. The push-pull ventilation type according to claim 4 , wherein the surface including each of the non-overlapping sides of the first honeycomb plate and the second honeycomb plate is orthogonal to the first honeycomb plate. Local exhaust ventilation.