JP2022070622A - Double-sided desk hood - Google Patents

Abstract

To deal with controlled wind speed requests in a double-sided desk hood which is installed on a laboratory table and used to contain a harmful atmosphere occurring due to experiments etc.SOLUTION: Opening/closing doors are provided on both sides of a desk hood so as to conduct work from both sides of the desk hood. An exhaust port for suctioning and exhausting an atmosphere in the desk hood is provided at a substantially center part of an upper surface of the desk hood. A pair of baffle plates which extends in a vertical direction so as to face opening surfaces on both sides of the desk hood is provided at a substantially center part within the desk hood. An air passage which guides air in a working space within the desk hood to the exhaust port is formed between the pair of baffle plates.SELECTED DRAWING: Figure 1

Description

The present invention relates to a double-sided tabletop hood.

When performing work such as chemical experiments, a local exhaust device is used to prevent harmful atmosphere such as toxic gas and odor generated by the work from diffusing into the surrounding environment. The local exhaust system consists of a hood (enclosure) that internally defines the work space that houses experimental equipment that creates a harmful atmosphere, and an exhaust facility that discharges the atmosphere in the work space to an appropriate place via a duct or the like. It is composed.

Local exhaust devices are roughly classified into "draft chambers" and "desktop hoods". The name may differ slightly depending on the manufacturer / seller.

As used herein, the term "fume hood" generally means one capable of meeting controlled wind speed requirements with the sash (opening and closing door) partially open and having a high degree of containment performance. As used herein, the term fume hood generally means a device that includes a leg (base) portion to a hood portion. In a fume hood, a sash is generally provided only on the front surface. There are also draft chambers with sashes on both the front and rear sides, but such draft chambers generally have a configuration in which two draft chambers are combined, and the front work space and the rear work space are separated. It is virtually permanently separated.

As used herein, the term "countertop hood" means one that is configured to be able to be installed on an existing laboratory table (workbench). In other words, the part of the laboratory table is not a component of the "tabletop hood". Also, general tabletop hoods do not meet the controlled wind speed requirements. In other words, the tabletop hood is designed on the premise that it is sufficient to secure the required containment performance with the sash closed in principle.

An example of a tabletop hood is described in Patent Document 1. The tabletop hood described in Patent Document 1 is provided with sashes (opening / closing doors) on the front surface and the rear surface, respectively, so that a single work space can be accessed from both sides of the tabletop hood, and is a "double-sided tabletop hood". Also called. Since the double-sided tabletop hood can access the work space from both sides of the hood, it is possible to significantly reduce the troublesome movement of the operator when performing experimental work. A sash provided only on the front surface is also called a single-sided tabletop hood.

In recent years, even a tabletop hood that is not originally designed to meet a controlled wind speed requirement may be required to meet a controlled wind speed requirement (that is, performance equivalent to that of a fume hood). In this case, it is possible to satisfy the control wind speed requirement by increasing the rotation speed of the exhaust fan, but there is a concern that the operating cost will increase due to the increase in the electricity cost. In addition, at the planning stage of new facilities, it is required to increase the duct size and fan capacity, so there is a concern that the amount of capital investment will increase.

The above problem becomes more prominent when the tabletop hood is double-sided. This is because the double-sided hood has a larger working space than the single-sided hood, so that the air suction efficiency is poor and the wind speed distribution on the opening surface tends to vary.

JP-A-2019-166433

An object of the present invention is to provide a double-sided tabletop hood compatible with a controlled wind speed having good air volume efficiency (wind speed efficiency).

According to one embodiment of the present invention, it is a double-sided tabletop hood installed on a laboratory table and for containing a harmful atmosphere generated by an experiment or the like, and work can be performed from both sides of the tabletop hood. As described above, opening / closing doors are provided on both sides of the tabletop hood, and an exhaust port for sucking and exhausting the atmosphere inside the tabletop hood is provided at substantially the center of the upper surface of the tabletop hood. A pair of baffle plates extending in the vertical direction are provided substantially in the center so as to face the opening surfaces on both sides of the tabletop hood, and air in the work space inside the tabletop hood is blown between the pair of baffle plates. A tabletop hood is provided in which an air flow path leading to the exhaust port is formed.

According to the present invention, it is possible to obtain a double-sided tabletop hood compatible with a controlled wind speed having good air volume efficiency (wind speed efficiency).

It is a perspective view of the tabletop hood which concerns on one Embodiment. It is a perspective view of the member (baffle plate, channel material) constituting an exhaust flow path. It is a perspective view which shows the method of attaching a baffle plate to a frame via a channel material. It is a perspective view of a channel material. It is a schematic vertical sectional view which shows the air flow formed in a tabletop hood. It is a schematic vertical sectional view which shows the airflow which is formed in a tabletop hood when there is no baffle plate.

Hereinafter, an embodiment of the double-sided tabletop hood 1 (hereinafter, simply referred to as “hood 1” for convenience) will be described with reference to the drawings. The hood 1 is installed on a laboratory table and is used to contain the harmful atmosphere generated by an experiment or the like from an experimental device or the like installed on the upper surface of the laboratory table inside the hood 1.

In each attached drawing, front (F), rear (B), left (L), right (R), top (U), and bottom (D) are displayed to distinguish the orientation. The hood 1 is generally symmetrical in the front-rear direction and is generally symmetrical in the left-right direction. For the sake of brevity, in principle, if the front component and the rear component have the same configuration, only one of them will be described below. The reference code attached to the front component is displayed as "number + F", the reference code attached to the rear component is displayed as "number + B", and if the number parts are the same, both have the same configuration. .. Further, in the following, as a general rule, if the component on the left side and the component on the right side have the same configuration, only one of them will be described. The reference code attached to the left component is displayed as "number + L", the reference code attached to the right component is displayed as "number + R", and if the numbers are the same, both have the same configuration.

It should be noted that in FIG. 1, since many members are displayed, some members that are not transparent (for example, a ceiling panel) may be shown transparently. As shown in FIG. 1, the hood 1 has a box-shaped hood body 10. The hood body 10 has a frame 12 and a plurality of outer panels 14 attached to the frame 12. The frame 12 can be formed by assembling a plurality of pillars and beams made of metal, for example, aluminum, into a substantially rectangular parallelepiped shape as a whole by a known joining technique such as screwing or welding.

The outer panel 14 can be formed from a suitable transparent material selected according to the application, for example, glass. As the transparent material, a transparent resin such as transparent PVC can also be used. The ceiling panel 14C of the outer panel 14 may be formed of an opaque metal material such as aluminum.

By attaching the outer panel 14 to the frame 12 by a known method, a hood body 10 having sufficient airtightness to suit the application is formed. The space inside the hood body 10 can be used as a work space substantially isolated from the space outside the hood body 10. The space inside the hood body 10 is divided into a work space 11F on the front side and a work space 11B on the rear side by the vertical baffle plate 20F on the front side and the vertical baffle plate 20B on the rear side, which will be described later (see particularly FIG. 5). ..

As shown in FIGS. 1 and 5, the plurality of outer panels 14 include a panel 14F arranged on the front surface of the hood body 10 and a panel 14B arranged on the rear surface of the hood body 10. The plurality of outer panels 14 include a ceiling panel 14C arranged on the ceiling surface of the hood body 10, a left panel 14L arranged on the left surface of the hood body 10, and a right panel 14R arranged on the right surface of the hood body 10. And are included.

The ceiling panel 14C, the left panel 14L, and the right panel 14R are always completely closed to the upper surface, the left surface, and the right surface of the hood body 1, respectively.

In particular, as clearly shown in FIG. 5, the front panel 14F closes only the upper part of the front surface of the hood body 10. Specifically, the panel 14F extends from a height position of about 2/3 of the total height of the hood body 10 to the ceiling portion of the hood body 10. That is, on the front surface of the hood body 10, an opening 16F is provided from the lower end of the hood body 10 (the height of the work surface 50 (see FIG. 5)) to a height position of about 2/3 of the total height of the hood body 10. ing. The same applies to the rear panel 14B.

As shown in FIGS. 1 and 5, a front sash (opening / closing door) 18F is attached to the frame 12 so as to be able to move up and down in order to open / close the front opening 16F. The sash 18F is stationary not only at the upper limit position where the opening 16F is completely opened and the lower limit position where the opening 16F is generally closed, but also at an arbitrary vertical position where the opening 16F is partially opened at an arbitrary opening. Can be done. When the sash 18F is in the lower limit position, the area of about 30 mm from the lower end of the opening 16F is opened without being blocked in order to prevent the negative pressure inside the hood body 10 from becoming excessively high even if the exhaust fan is always operated. (See FIG. 5). By raising the sash 18F by an appropriate distance from the lower limit position, the operator can access the work space 11F on the front side. The relationship between the rear sash (opening / closing door) 18B and the rear opening 16B is also the same.

A vertical baffle plate 20F on the front side and a vertical baffle plate 20B on the rear side are provided in parallel with the sash 18F on the front side and the sash 18R on the rear side, respectively, at a position substantially center in the front-rear direction of the hood body 10. The vertical baffle plate 20F and the vertical baffle plate 20B extend in the vertical direction in parallel with each other with a space in the front-rear direction. Each of the vertical baffle plates 20F and 20B may be composed of two plate materials as clearly shown in FIG. 3, or may be composed of a single plate material instead.

A central pillar 12R on the right side and a central pillar 12L on the left side extend in the vertical direction at the center of the right side surface and the left side surface of the hood body 10 in the front-rear direction, respectively. The central pillars 12R and 12L form a part of the pillars constituting the frame 12.

The central pillar 12R is provided with a katakana "U" shape, or in other words, a square bracket (]) -shaped channel material 24R on the right side. The upper end surface of the channel material 24R is closed in the vertical direction by the top plate 246R. The lower end surface of the channel material 24R is open in the vertical direction. The channel material 24R has a base wall 241R that abuts on the central support column 12R, and side walls 242R and 243R that rise from the front end and the rear end of the base wall 241R toward the left. The channel material 24R is screwed to the central pillar 12R by a plurality of screw SCWs that pass through the through hole formed in the base wall 241R and are screwed to the right into the screw hole formed in the central pillar 12R. See FIG. 4 for the single shape of the channel material 24R. The same applies to the relationship between the channel material 24L on the left side and the central column 12L on the left side.

The right end of the vertical baffle plate 20F on the front side passes through a through hole formed in the right end of the vertical baffle plate 20F, and at the same time, a plurality of screws screwed backward into the screw hole formed in the side wall 242R of the channel material 24R on the right side. It is screwed to the side wall 242R by SCW. The left end of the vertical baffle plate 20F has the same configuration as the left end of the vertical baffle plate 20F, and is screwed to the side wall 242L of the left channel material 24L in the same manner as the right end of the vertical baffle plate 20F. There is. The vertical baffle plate 20B on the rear side is attached to the channel material 24R on the right side in the same manner as described above.

When the vertical baffle plates 20F and 20B are fixed in a predetermined position with respect to the frame 12 of the hood body 10 as described above, they are thin surrounded by the vertical baffle plates 20F and 20B and the channel materials 24R and 24L. A rectangular parallelepiped air flow path 41 is formed (see FIG. 5).

Above each of the vertical baffle plates 20F and 20B, the front slant baffle plate 22F and the rear slant baffle plate 22B are inclined toward the ceiling so as to be in contact with the upper ends of the vertical baffle plates 20F and 20B. And are arranged. The slant baffle plates 22F and 22B can be formed by, for example, forming a metal plate such as an aluminum plate by press molding. The slant baffle plate 22F and the slant baffle plate 22B have substantially anteroposterior symmetry (mirror plane symmetry with each other).

As shown in FIG. 2, the slant baffle plates 22F and 22B pass through the through holes formed in the slant baffle plates 22F and 22B, and the beams 12C on the ceiling of the hood body 10 (see FIG. 1 for the beams). It is screwed to the beam 12C by a plurality of screws SCW screwed upward into the screw holes formed in the beam. When the slant baffle plates 22F and 22B are fixed in a predetermined position with respect to the frame 12 of the hood body 10, they are substantially isosceles surrounded by the slant baffle plates 22F and 22B and the ceiling panel (top panel) 14C. An air flow path 42 having a triangular cross section is formed (see FIG. 5). An exhaust port 44 is provided at a substantially central portion of the ceiling panel 14C, and the air flow path 42 communicates with the exhaust port 44.

As shown in FIG. 2, two notches 32F are formed on the trailing edge of the front slant baffle plate 22F. Two notches 32B are formed on the front edge of the rear slant baffle plate 22B. When the two slant baffle plates 22F and 22B are combined, the notch 32F and the notch 32B are combined to form a rectangular hole 34. The air flow path 41 and the air flow path 42 communicate with each other through the hole 34. The air flow path 41 and the air flow path 42 are collectively referred to as an exhaust flow path 40.

An exhaust duct (not shown) provided with an appropriate exhaust device (not shown) such as an exhaust fan is connected to an exhaust port 44 provided on the ceiling of the hood body 10. By operating the exhaust device, the air in the exhaust flow path 40 can be sucked.

The width in the front-rear direction of the rectangular hole 34 described above is larger than the distance between the front surface of the vertical baffle plate 20F and the rear surface of the vertical baffle plate 20B. Therefore, when the slant baffle plates 22F and 22B are combined with the vertical baffle plates 20F and 20B, slit-shaped openings 35F and 35B are formed by the front end portion and the rear end portion of the rectangular hole 34. Air flows into the exhaust flow path 40 (air flow path 42) from the front work space 11F and the rear work space 11B through these slit-shaped openings 35F and 35B, respectively.

Two notches 36F are formed on the front edge of the slant baffle plate 22F on the front side. Two notches 36B are formed on the trailing edge of the rear slant baffle plate 22B. When the front slant baffle plate 22F and the rear slant baffle plate 22B are screwed to the beam 12C of the ceiling portion of the frame 12, slit-shaped openings 38F and 38B are formed between the notches 36F and 36B and the ceiling panel 14C. Will be done. Air flows into the exhaust flow path 40 (air flow path 42) from the work space 11F and the work space 11B through these slit-shaped openings 38F and 38B, respectively.

A plurality of slit-shaped openings 28 extending in the horizontal direction are formed in the lower half of the vertical baffle plate 20F on the front side. The slit-shaped openings 28 are distributed substantially evenly over the entire lower half of the vertical baffle plate 20F. Air flows into the exhaust flow path 40 (air flow path 41) from the work space 11F on the front side through the slit-shaped opening 28. A plurality of slit-shaped openings such as the lower half are not formed in the upper half of the vertical baffle plate 20F. A gap 30F is provided between the lower end edge of the vertical baffle plate 20F and the work surface 50 (upper surface of the workbench). Air flows into the exhaust flow path 40 (air flow path 41) from the work space 11F on the front side through the gap 30F. In the above points, the same applies to the vertical baffle plate 20B on the rear side.

Especially as clearly shown in FIG. A plurality of slit-shaped openings 33 extending in the vertical direction are formed at the front and rear corners where the base wall 24R1 of the channel material 24R on the right side and the side walls 242R and 243R are connected. The slit-shaped opening 33 is provided in the lower half portion of the channel material 24R, and is not provided in the upper half portion. Air flows into the exhaust flow path 40 (air flow path 41) from the work space 11F on the front side through the slit-shaped opening 33 at the front corner portion of the channel material 24R. Air flows into the exhaust flow path 40 (air flow path 41) from the rear work space 11B through the slit-shaped opening 33 at the rear corner of the channel material 24R. The overlapping allowance between the side walls 242R and 243R and the vertical baffle plates 20F and 20B is set so that the slit-shaped openings 33F and 33B are not blocked by the vertical baffle plates 20F and 20B. In the above points, the channel material 24L is similarly configured.

In particular, as shown in FIG. 3, the front vertical baffle plate 20F can be composed of an upper member 20FU constituting the upper half portion of the vertical baffle plate 20F and a lower member 20FD constituting the lower half portion. .. In one configuration example, the upper member 20FU can be formed of a transparent material, specifically, for example, a transparent resin material, and more specifically, for example, a transparent PVC plate. This makes it possible for an operator standing in front of the front surface (rear surface) of the hood 1 to easily see the work space on the rear surface (front surface) side of the hood 1. The lower member 20FD can be formed from a resin decorative plate having a melamine resin as a surface material. The lower member 20FD may be formed of a metal plate, for example, an aluminum plate, which has been appropriately coated, for example, a melamine coating. By forming the surface of the lower member 20FD with a melamine resin, it is possible to provide desired chemical resistance. Forming the surface material from an opaque material such as a melamine resin is also beneficial when blindfolding (making the rear side invisible from the front side) is required. As the surface material, an appropriate one can be selected according to the required performance (heat resistance, chemical resistance, etc.). In the above points, the rear vertical baffle plate 20B can be similarly configured.

Instead of the above, both the upper member 20FU and the lower member 20FD can be formed of a transparent material. The entire vertical baffle plate 20F may be configured as an integral part (single member). In this case, the entire vertical baffle plate 20F can be formed of a single transparent material, specifically, for example, a transparent resin material, and more specifically, for example, a transparent PVC plate. In this case, only the lower half of the vertical baffle plate 20F may be painted. In the above points, the rear vertical baffle plate 20B can be similarly configured.

Next, the airflow in the work space will be described by taking the airflow in the work space 11F on the front side as an example. As shown in FIG. 5, the front sash 18F is raised so that approximately ½ of the lower side of the front opening 16F is opened. The rear opening 16B is generally closed by the rear sash 18B at the lower limit position (with a gap of about 30 mm as described above). Here, when an exhaust fan interposed in an exhaust duct (not shown) is operated, a suction force acts on the exhaust port 44, and the slit-shaped opening 28 and the channel material 24R provided in the lower half of the vertical baffle plate 20F are provided. , Exhaust flow path 40 (air flow) through a slit-shaped opening 33 provided in the front corner of 24L, a gap 30F between the lower end edge of the vertical baffle plate 20F and the work surface 50 (upper surface of the workbench). Air is drawn into the road 41). The openings 28 and 32 and the gap 30F are distributed substantially evenly in the region facing the opening surface 52 (meaning the region of the opening 16F that is not blocked by the sash 18F; the same applies hereinafter). , The air outside the hood body 10 passes through the opening surface at a substantially uniform wind speed (air flow velocity) over the entire area of the opening surface 52, and is drawn into the front work space 11F. The airflow at this time is indicated by an arrow in FIG.

The exhaust flow path 40 (air flow) is also from the slit-shaped opening 38F of the slant baffle plate 22F on the front side and the slit-shaped opening 35F formed between the slant baffle plate 22F on the front side and the vertical baffle plate 20F on the front side. Air is drawn into the road 42). This air flow can prevent air and gas from staying in the upper region of the work space 11F. Further, since the lower surface of the slant baffle plate 22F is inclined so as to become higher toward the front side, it is possible to further prevent air from staying between the openings 38F and the openings 35F.

At this time, air is also drawn into the exhaust flow path 40 from the work space 11B on the rear side, but the flow rate is small because the sash 18B on the rear side blocks the entire opening 16B.

As a comparative example, the air flow in the hood body 10 when the vertical baffle plates 20F and 20B and the slant baffle plates 22F and 22B are removed is shown by arrows in FIG. The configuration shown in FIG. 6 is substantially the same as the configuration of the conventional double-sided tabletop hood. In this case, since the air flows toward the exhaust port 44 immediately after passing through the opening surface 52, the wind speed at the upper part of the opening surface 52 tends to be high and the wind speed at the lower part of the opening surface tends to be low. In the case of FIG. 6, in order to realize a sufficient wind speed even in the lower part of the opening surface 52, it is necessary to increase the rotation speed of the exhaust fan as compared with the case of FIG. It is possible to achieve a sufficient wind speed at the lower part of the opening surface 52 by lowering the position of the sash 18F to some extent, but the workability is reduced.

According to the above embodiment, the wind speed distribution on the opening surface can be made uniform, and the controlled wind speed can be easily supported. Therefore, it is not necessary to unnecessarily increase the rotation speed of the exhaust fan in order to satisfy the control wind speed requirement, and the running cost can be reduced. In addition, deterioration of air conditioning efficiency in the laboratory can be prevented.

Further, according to the above embodiment, since at least the upper half of the front vertical baffle plate 20F and the front vertical baffle plate 20B is transparent, it is easy to open and close the sash from one side to the other side of the hood body 10. Can be grasped. Therefore, it is possible to prevent the tabletop hood 1 from being misused.

The double-sided tabletop hood 1 is operated while being mounted on a laboratory table provided in the center of the laboratory. According to the above embodiment, since at least the upper half of the baffle plates 20F and 20R is transparent (of course, the front, rear, right and left outer panels 14 are also transparent), the tabletop hood 1 is used in the laboratory. By installing it in the laboratory, it does not make the laboratory feel small. That is, the design of the tabletop hood 1 is excellent. If the entire baffle plates 20F and 20R are transparent, the design of the tabletop hood 1 becomes more excellent.

According to the above embodiment, the vertical baffle plate 20F, the vertical baffle plate 20B, the slant baffle plate 22F and the slant baffle plate 22B are screwed to the frame 12 of the hood body 10 and are easily removed from the frame 12. be able to. Therefore, it can be used as a normal double-sided tabletop hood when a large work space is required when control wind speed support is not required. Further, since the baffle plates 20F, 20R, 22F, 22B can be easily removed, the baffle plates 20F, 20R, 22F, 22B and the inside of the hood body 10 can be easily cleaned. Further, according to the above embodiment, since the exhaust flow path 40 is composed of a plurality of parts, that is, vertical baffle plates 20F, 20B and slant baffle plates 22F, 22B (and channel materials 24R, 24L), the exhaust flow flows. It is easier to put on and take off than when the road 40 is composed of one or two large parts. Further, when each of the vertical baffle plates 20F and 20B is divided into an upper half portion and a lower half portion, handling becomes easier.

Further, since the vertical baffle plates 20F and 20B are attached to the frame 12 of the hood body 10 via the channel materials 24R and 24L, the attachment work can be performed as compared with the case where the vertical baffle plates 20F and 20B are directly attached to the frame 12. It will be easy.

In the above embodiment, the slit-shaped openings 33 are provided at the corners of the channel materials 24R and 24L, and it is more preferable to do so, but the openings 33 can be omitted. Further, the configurations of the slant baffle plates 22F and 22B are not limited to those shown in the drawings, and the shapes may be changed at least partially.

1 Desktop hood 10 Hood body 12 Frame 14 Outer panel 18F, 18B Open / close door (sash)
20F, 20B baffle plate (vertical baffle plate)
Upper half of 20FU baffle plate 20FD Lower half of baffle plate 24R, 24L Mounting member (channel material)
33 Channel material slit 44 Exhaust port

Claims (6)

It is a double-sided tabletop hood that is installed on a laboratory table and is used to contain the harmful atmosphere generated by experiments.
Opening and closing doors are provided on both sides of the tabletop hood so that work can be performed from both sides of the tabletop hood.
An exhaust port for sucking and exhausting the atmosphere inside the tabletop hood is provided at substantially the center of the upper surface of the tabletop hood.
A pair of baffle plates extending in the vertical direction so as to face the opening surfaces on both sides of the tabletop hood are provided at substantially the center of the tabletop hood, and the work inside the tabletop hood is provided between the pair of baffle plates. A tabletop hood characterized in that an air flow path for guiding air in a space to the exhaust port is formed. The tabletop hood according to claim 1, wherein the tabletop hood has a hood body having a frame and an outer panel, and each baffle plate is removable from the hood body. The tabletop hood according to claim 2, wherein each baffle plate is attached to a side portion of the hood body via a mounting member. The tabletop hood according to claim 3, wherein a slit is formed in the mounting member, and air in the work space can flow into the air flow path through the slit. The tabletop hood according to claim 1, wherein each baffle plate has an upper half portion and a lower half portion configured as separate parts. The tabletop hood according to claim 1, wherein each baffle plate is transparent.

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