Laboratory table with desktop type hood

Abstract

To provide a laboratory table with a desktop type hood that enables experiments involving the handling or generation of harmful substances to be conducted on the laboratory table, offers good working efficiency for an operator, reliably exhausts gases with a high specific gravity to enable preventing deterioration of a working environment in a laboratory, and enables suppressing a reduction in space efficiency due to the installation of a dry type scrubber.SOLUTION: A laboratory table with a desktop type hood comprises: a flat work table 1 on which experiments are conducted; a hood 2 which is positioned above the work table 1; and a base 3 which is positioned below the work table 1. The hood 2 is capable of sealing a work space on the work table 1 and the hood 2 has doors 5a, 5b, 6a, 6b that can be opened / closed. The work table 1 is provided with a suction port 8 that is open toward an interior of the base 3, and the suction port 8 is connected to a suction device 14 via the interior of the base 3.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a laboratory bench with a desktop hood.

Background Art

[0002] Laboratories in fields such as biotechnology, pharmaceuticals, and semiconductors are equipped with laboratories for conducting various chemical experiments and research, and various experiments are carried out on the laboratory benches installed in those laboratories. However, experiments involving handling harmful substances or experiments that generate harmful substances are conducted in a draft chamber provided separately from the laboratory bench within the laboratory. Since the draft chamber strongly sucks in and exhausts the internal gas, harmful gases do not stay inside or diffuse to the outside, ensuring safety. However, conducting experiments in a draft chamber is less workable compared to conducting experiments on a laboratory bench. Therefore, it is common to conduct experiments in a draft chamber only when the substances handled or generated in the experiment are highly dangerous, and to conduct experiments on a laboratory bench when the danger is low. When using the laboratory bench and the draft chamber appropriately according to the danger of substances and the like in this way, the operator needs to move back and forth between the laboratory bench and the draft chamber, resulting in poor work efficiency.

[0003] Therefore, a laboratory bench with a desktop hood attached to the laboratory bench may be used. Experiments are conducted in the space surrounded by the desktop hood on the laboratory bench, and the gas in this space is sucked upward above the hood and exhausted to the outside. The gas exhausted in this way is introduced into a dry scrubber through an exhaust duct from the viewpoints of safety and hygiene, and is made into a harmless gas that has been purified by the dry scrubber and has no impact on the environment or the neighborhood, and then released to the outside. A dry scrubber for such purification treatment is generally installed outside the laboratory.

[0004] The experimental bench described in Patent Document 1 has an exhaust section that forcibly exhausts the gas in the working space composed of a ceiling plate section, left and right side plate sections, a back plate section, and a workbench. The exhaust section includes an exhaust port located below the working space for exhausting the gas in the working space, an exhaust passage that is the flow path of the exhausted gas, an exhaust duct connected to the outside of the experimental bench, and the like. Further, an air supply fan and an air supply box are integrally arranged above the ceiling plate section.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In a general desktop hooded experimental bench, as described above, the gas in the space inside the hood is sucked upward and exhausted. However, if the specific gravity of the gas in the space inside the hood is large, the gas cannot be sufficiently exhausted above the hood, and it spreads and stays inside the hood. The gas thus staying diffuses outside the hood when the power of the fan is turned off and the hood is opened, deteriorating the working environment in the laboratory. In particular, when vapors such as organic solvents (chloroform, etc.) harmful to the human body are used or generated in the experiment, it is dangerous if the vapor diffuses into the laboratory, increasing the risk of health damage to the operator.

[0007] In the experimental bench described in Patent Document 1, the front of the working space is entirely open, and due to the poor airtightness and the high possibility of gas diffusing to the outside, the risk of health damage to the operator is high depending on the type of gas. Further, this experimental bench supplies gas from the air supply fan and the air supply box above the ceiling plate section into the inside of the working space. The gas in the working space is forcibly exhausted from the exhaust port of the workbench below the working space to the exhaust passage, but there is a possibility that the gas with a small specific gravity cannot be sufficiently exhausted downward from the exhaust port.

[0008] In addition, a dry scrubber for purifying exhaust gas requires a relatively large installation space. Therefore, it may compress the space outside the laboratory or on the rooftop, and there may be cases where the dry scrubber cannot be installed due to the inability to secure the installation space.

[0009] Therefore, an object of the present invention is to provide a tabletop hood-equipped experimental bench that can perform experiments involving handling or generating harmful substances on the experimental bench, has good working efficiency for operators, has high reliability in exhausting gases with a large specific gravity, can prevent deterioration of the working environment in the laboratory, and can suppress a decrease in space efficiency due to the installation of a dry scrubber.

Means for Solving the Problems

[0010] The tabletop hood-equipped experimental bench of the present invention includes a flat working table on which experiments are performed, a hood located above the working table, and a base located below the working table. The hood can seal the working space on the working table, the hood has an openable and closable door portion, the working table is provided with a suction port that opens toward the inside of the base, and the suction port is connected to a suction device via the inside of the base. It may further have a pipe attached to the top plate portion of the hood, connected to the suction device, and communicating with the working space. The pipe attached to the top plate portion of the hood preferably incorporates a valve mechanism, and the valve mechanism can adjust the ratio of the flow rate of the gas sucked from the pipe to the flow rate of the gas sucked from the suction port. A dry scrubber may be provided inside the base, located between the suction port and the suction device. The planar shape of the working table is substantially rectangular, and the working table includes a suction plate located at the center in the short side direction and extending in the long side direction, and a plurality of the suction ports may be provided on the suction plate. The suction device has an air volume of 1200 m 3 / h or more and 3000 m3 It may include a fan below / h. The opening ratio of the suction port in the workbench may be 20% - 80%.

Advantages of the Invention

[0011] According to the desktop experimental bench with a hood of the present invention, experiments involving handling or generating harmful substances can also be carried out on the experimental bench. The working efficiency of the operator is good, the reliability of exhausting gases with a large specific gravity is high, the deterioration of the working environment in the laboratory can be prevented, and the reduction of space efficiency due to the installation of a dry scrubber can be suppressed.

Brief Description of the Drawings

[0012]

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Embodiments for Carrying out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a laboratory bench with a tabletop hood according to the first embodiment of the present invention, and FIG. 2 is a partially cut-away front view thereof. This laboratory bench with a tabletop hood has a flat work table 1, a hood 2 located above the work table 1, and a base 3 located below the work table 1. The hood 2 is composed of a top plate portion 4, a front plate portion 5, a rear plate portion 6, and two side plate portions 7, and has a hollow substantially rectangular parallelepiped shape with an opening at the bottom. By placing this hood 2 on the upper surface of the work table 1, the space above the work table 1 can be sealed. However, at least a part of the front plate portion 5, the rear plate portion 6, and the two side plate portions 7 is in the form of a door that can be opened and closed. In the example shown in FIGS. 1 and 2, two door portions 5a and 5b that can be opened and closed by sliding up and down are provided on the front plate portion 5. Similarly, two door portions 6a and 6b that can be opened and closed by sliding up and down are provided on the rear plate portion 6. The front plate portion 5 including the door portions 5a and 5b in the present embodiment is made of a material having light transmissivity such as glass so that the working space inside the hood 2 can be visually recognized.

[0014] In the working table 1 of the desktop experimental table with a hood according to this embodiment, a suction port 8 is provided. Specifically, the working table 1 of this embodiment is in an elongated rectangular shape, and includes a main body portion 1a, a central portion 1b fitted into a long hole portion 1a1 located at the center in the short side direction (direction A in FIG. 1) of the main body portion 1a and extending in the long side direction (direction B in FIG. 1), and a suction plate 1c fitted into a long hole portion 1b1 located at the center in the short side direction A of the central portion 1b and extending in the long side direction B. In the suction plate 1c shown enlarged in FIG. 3, suction ports 8, which are a number of long groove-shaped (slit-shaped) holes extending in the short side direction A, are formed to be parallel to each other. That is, the suction port 8 is provided in the suction plate 1c located at the center in the short side direction A of the working table 1 and extending in the long side direction B. The working space above the working table 1 and the space in the base 3 below communicate with each other through the suction port 8. The opening ratio of the suction port 8 in the working table 1 is preferably 20% to 80%, and more preferably 30% to 50%. When the opening ratio of the suction port 8 is 20% or more, the pressure loss can be kept low, and the generation of wind noise can be suppressed. Also, when the opening ratio of the suction port 8 is 80% or less, it can act as an opening having a gas suction effect, and the risk of accidentally dropping substances can be kept low. The opening shape of the suction port 8 is not limited to the slit shape shown, and may be a punched hole shape or the like. When the opening shape of the suction port 8 is slit-shaped, the interval between the suction ports 8, that is, the width of the rib-shaped portion, is preferably 4 mm or more and 20 mm or less, and more preferably 6 mm or more and 12 mm or less.

[0015] Inside the base 3 below the work table 1 of the desktop experimental table with a hood according to this embodiment, a dry scrubber 9 is arranged. FIG. 4 is an exploded perspective view showing the work table 1 (including the suction plate 1c) of this embodiment and each member of the dry scrubber 9 in the base 3. In the desktop experimental table with a hood according to this embodiment, dry scrubbers 9 are respectively configured on both sides with the center of the longitudinal direction B of the base 3 interposed therebetween. FIG. 2 shows a part of the base 3 cut away so that the dry scrubber 9 on the right side can be seen, and FIG. 4 shows the dry scrubber 9 on the right side and the work table 1 above it. As a specific configuration of the dry scrubber 9 in the base 3, a pair of hollow downstream ducts 10a and 10b connected to each other are arranged at the lower part in the base 3. Further, one end of a hollow elbow 11 that bends upward is connected to the downstream duct 10b, and a hollow round duct 12 extending upward is connected to the other end of the elbow 11. The round duct 12 of the dry scrubber 9 is connected to a suction device 14 via a pipe 13 or the like. As an example, the suction device 14 includes a fan or the like that generates an air volume of 1200 m 3 / h to 3000 m 3 / h.

[0016] Above the downstream ducts 10a and 10b, casings 15a and 15b that open upward and communicate with the downstream ducts 10a and 10b are respectively arranged, and a plurality of parts filters 16 are inserted into each of the casings 15a and 15b. In FIG. 4, some of the parts filters 16 have already been inserted into the casings 15a and 15b, and the remaining parts filters 16 are shown in a state before being inserted into the casings 15a and 15b. The upper openings of the casings 15a and 15b face the elongated hole portions 1a1 of the main body portion 1a of the work table 1 located above the base 3. A communication hole 1a2 that communicates with the round duct 12 is provided in the main body portion 1a. Prefilters 17a and 17b are respectively arranged at positions facing the upper openings of the casings 15a and 15b and below the central portion 1b of the work table 1. Further, above the prefilters 17a and 17b, trays 19a and 19b supported by a receiving plate 18 are respectively arranged. And above the trays 19a and 19b, the suction plate 1c of the above-described work table 1 is arranged. The suction plate 1c is located at a position facing the trays 19a and 19b.

[0017] A description will be given of the case of conducting an experiment using this table-type experimental bench with a hood. Open either one of the door portions 5a and 5b of the front plate portion 5 and the door portions 6a and 6b of the rear plate portion 6, place the substances used in the experiment in the working space on the working table 1 and inside the hood 2, and conduct the experiment by, for example, inserting the hand of the operator. Among the gases present on the working table 1 that are used in the experiment or generated during the experiment, gases with a high specific gravity (for example, vapors of organic solvents such as chloroform) do not rise much toward the top plate portion 4 side (the upper part of the working space), but are drawn downward from the suction ports 8 of the suction plate 1c by the suction action of the suction device 14 against their weight. The gas drawn in from the suction ports 8 is purified through the pre-filters 17a and 17b and the parts filter 16. Even if it is a gas harmful to the human body, it becomes a harmless gas by being purified by the pre-filters 17a and 17b and the parts filter 16. The pre-filters 17a and 17b are filters that collect relatively large dust in the gas. The parts filter 16 has activated carbon built in at least a part thereof and is a filter that can remove harmful substances in the gas. The gas purified by the dry scrubber 9 including these pre-filters 17a and 17b and the parts filter 16 is drawn into the suction device 14 through the downstream ducts 10a and 10b, the elbow 11, the round duct 12, the pipe 13, etc., and is further discharged from the suction device 14 to the outside. Thus, according to this embodiment, since the working space on the working table 1 is sealed by the hood 2 composed of the top plate portion 4, the front plate portion 5, the rear plate portion 6, and the two side plate portions 7, excluding the door portions 5a, 5b, 6a, and 6b, the diffusion of the gas in the working space to the outside is suppressed. Further, the gas with a heavy specific gravity is lowered without being retained in the hood 2, purified by the dry scrubber 9 to be made harmless, and then discharged to the outside. Therefore, even in an experiment that handles or generates harmful gases, it can be conducted on the experimental bench without moving to the draft chamber, eliminating the need for the operator to move back and forth between the experimental bench and the draft chamber, and improving the working efficiency. Also, since the dry scrubber 9 can be configured inside the base 3 below the working table 1, there is no need to secure installation space outside the research institute or on the rooftop, and space saving is possible.There is no problem that the dry scrubber 9 cannot be installed because there is no space for installation. In addition, if accidentally spilled or overflowed liquid chemicals or the like enter the suction port 8, the chemicals that have passed through the suction port 8 are held in the trays 19a and 19b and will not be further contaminated. Therefore, providing the suction port 8 on the work table 1 does not make the experiment difficult or increase the risk.

[0018] Also, in the experimental table with a tabletop hood of the present embodiment, as shown in FIG. 4, since the parts filter 16 is inserted into the casings 15a and 15b that are located above the downstream ducts 10a and 10b and open upward, the parts filter 16 is configured to be pulled out upward from within the casings 15a and 15b. Since the dry scrubber 9 has such a shape and configuration, the parts filter 16 can be installed, removed, and replaced without interfering with the storage space of the experimental table with a tabletop hood, and the workability is good and the space efficiency is good.

[0019] FIG. 5 is a perspective view of an experimental table with a tabletop hood according to a second embodiment of the present invention. The experimental table with a tabletop hood of the present embodiment has a pipe 20 attached to the top plate portion 4 of the hood 2 in addition to the configuration of the experimental table with a tabletop hood of the first embodiment. This pipe 20 is connected to the suction device 14 in the same manner as the pipe 13, communicates with the working space inside the hood 2, and incorporates a valve mechanism (not shown). Since the other configurations and the operational effects are the same as those of the experimental table with a tabletop hood of the first embodiment, the description thereof is omitted.

[0020] According to the tabletop experimental bench with a hood of the present embodiment, similar to the tabletop experimental bench with a hood of the first embodiment, in addition to being able to suck in a gas with a large specific gravity from the suction port 8 provided on the work table 1 and remove it from the work space, a gas with a small specific gravity can be removed from the work space by sucking it from the upper pipe 20. Both the pipe 13 that mainly sucks in a gas with a large specific gravity and the pipe 20 that mainly sucks in a gas with a small specific gravity are connected to the same suction device 14. The pipe 20 of the present embodiment is provided with a valve mechanism (not shown), for example, a throttle mechanism capable of changing the opening degree of the pipe 20. By changing the opening degree of the pipe 20 with this valve mechanism, the ratio between the flow rate of the gas sucked from the pipe 20 and the flow rate of the gas sucked from the suction port 8 via the pipe 13 can be changed. Therefore, according to the danger (harmfulness) of the gas, the removal efficiency of the gas with a large specific gravity and the gas with a small specific gravity can be arbitrarily adjusted.

Example

[0021] Hereinafter, specific examples and comparative examples of the present invention will be described. In each example and each comparative example of the present invention described below, when chloroform, which is an example of a gas with a large specific gravity, is generated in a tabletop experimental bench with a hood, the simulation results of how it diffuses and stays in the work space above the work table 1 and inside the hood 2 are shown. The colored part is above the control concentration, and the darker the color, the higher the concentration. Specifically, a beaker 21 (see FIGS. 6 to 11) with a capacity of 500 ml is placed on the work table 1, and the behavior of the vapor when 100 ml of liquid chloroform is put into the beaker and volatilized is shown by airflow analysis. FIGS. 6 to 11 show the concentration of the gas G in the work space represented by the density of the grid pattern. The planar shape of the work table 1 in each example and each comparative example is a rectangle with a length in the short side direction A of 1500 mm and a length in the long side direction B of 3000 mm. The height from the work table 1 to the top plate portion 4 is about 1700 mm. Therefore, a work space of about 1500 mm × about 3000 mm × about 1700 mm is configured. The suction device 14 has an air volume of 2400 m 3It includes a fan of / h. In Examples 1 to 3 shown below, the opening shape of the suction port 8 is slit-shaped, the interval between the suction ports 8 (the width of the rib-shaped part) is 10 mm, and the opening ratio of the suction port 8 in the work table 1 is about 42%.

[0022] [Example 1] In Example 1 of the present invention, a laboratory bench with a desktop hood similar to the second embodiment shown in FIG. 5 was used, and the door part 5a of the front plate part 5 and the door part 6a of the rear plate part 6 facing the door part 5a were opened. Then, chloroform vapor was generated under the above-described conditions, the valve mechanism (throttle mechanism) of the pipe 20 was closed, and the suction force of the suction device 14 acted entirely on the pipe 13 side so that the gas flowed through the dry scrubber 9 at an SV value (space velocity) of 20,000 to 30,000. As a result, in this example, as shown in FIGS. 6(A) and 6(B), the generated chloroform vapor did not spread widely in the working space and was introduced into the dry scrubber 9 (see FIG. 4) in the base 3. Therefore, deterioration of the environment outside the laboratory bench with a desktop hood could be suppressed.

[0023] [Example 2] In Example 2 of the present invention, a laboratory bench with a desktop hood similar to the second embodiment shown in FIG. 5 was used, and the door parts 5a and 5b of the front plate part 5 were opened. Then, chloroform vapor was generated under the above-described conditions, the valve mechanism (throttle mechanism) of the pipe 20 was closed, and the suction force of the suction device 14 acted entirely on the pipe 13 side so that the gas flowed through the dry scrubber 9 at an SV value (space velocity) of 20,000 to 30,000. As a result, also in this example, as shown in FIGS. 7(A) and 7(B), the generated chloroform vapor did not spread widely in the working space and was introduced into the dry scrubber 9 (see FIG. 4) in the base 3. Therefore, deterioration of the environment outside the laboratory bench with a desktop hood could be suppressed.

[0024] [Example 3] In Example 3 of the present invention, a table-type experimental bench with a desktop hood similar to the second embodiment shown in FIG. 5 was used, and the door portion 5a of the front plate portion 5 and the door portion 6a of the rear plate portion 6 facing the door portion 5a were opened. Then, chloroform vapor was generated under the aforementioned conditions, and the valve mechanism (throttling mechanism) of the pipe 20 was slightly opened so that the suction device 14 acted on both the pipe 13 side and the pipe 20 side. Specifically, the ratio of the suction force acting on the pipe 13 side to the suction force acting on the pipe 20 side was set to 1:9. As a result, also in this example, as shown in FIGS. 8(A) and 8(B), the generated chloroform vapor did not spread widely within the working space and was introduced into the dry scrubber 9 (see FIG. 4) in the base 3. Therefore, deterioration of the environment outside the table-type experimental bench with a desktop hood could be suppressed.

[0025] [Example 4] In Example 4 of the present invention, a table-type experimental bench similar to the second embodiment shown in FIG. 5 was used, and the door portion 5a of the front plate portion 5 and the door portion 6a of the rear plate portion 6 facing the door portion 5a were opened. However, in the table-type experimental bench of this example, the opening ratio of the suction port 8 in the work table 1 was 10%. In this table-type experimental bench with a desktop hood, chloroform vapor was generated under the aforementioned conditions, the valve mechanism (throttling mechanism) of the pipe 20 was closed, and the suction force of the suction device 14 acted entirely on the pipe 13 side so that the gas flowed through the dry scrubber 9 at an SV value (space velocity) of 20,000 to 30,000. As a result, in this example, as shown in FIG. 9, although the generated chloroform vapor spread slightly within the working space, deterioration of the environment outside the table-type experimental bench with a desktop hood was suppressed to some extent. However, the degree of suppression was small. This is presumably because the opening ratio of the suction port 8 in the work table 1 was outside the preferable range (20% to 80%).

[0026] [Comparative Example 1] In Comparative Example 1, a bench-type experimental table with a tabletop hood similar to the second embodiment shown in FIG. 5 was used, and the door portions 5a of the front plate portion 5 and the door portions 6a of the rear plate portion 6 facing the door portion 5a were opened. Then, chloroform vapor was generated under the aforementioned conditions, the valve mechanism (throttle mechanism) of the pipe 20 was opened, and although not shown, the suction port 8 below the work table 1 was blocked so that the suction device 14 acted only on the pipe 20 side. As a result, in this comparative example, as shown in FIGS. 10(A) and 10(B), the generated chloroform vapor widely diffused and remained in the work space. When the door portions 5a, 5b, 6a, and 6b were opened in this state, it was found that the chloroform vapor spread outside the bench-type experimental table with a tabletop hood and deteriorated the environment.

[0027] [Comparative Example 2] In Comparative Example 2, a bench-type experimental table with a tabletop hood similar to the second embodiment shown in FIG. 5 was used, and the door portions 5a and 5b of the front plate portion 5 were opened. Then, chloroform vapor was generated under the aforementioned conditions, the valve mechanism (throttle mechanism) of the pipe 20 was opened, and although not shown, the suction port 8 below the work table 1 was blocked so that the suction device 14 acted only on the pipe 20 side. As a result, also in this comparative example, as shown in FIGS. 11(A) and 11(B), the generated chloroform vapor widely diffused and remained in the work space. When the power of the fan was turned off and the door portions 5a, 5b, 6a, and 6b were opened in this state, it was found that the chloroform vapor spread outside the bench-type experimental table with a tabletop hood and deteriorated the environment.

[0028] [Results] Comparing FIGS. 6 to 9 with FIGS. 10 to 11, it is clear that in Examples 1 to 4 of the present invention, compared with Comparative Examples 1 and 2, it is possible to suppress the wide diffusion and retention of a gas with a large specific gravity (vapor of chloroform) in the working space. In particular, according to Examples 1 to 3, the gas in the hood 2 on the work table 1 can be sucked from the suction port 8 without being diffused and without leaking from the hood 2. Therefore, the risk of environmental degradation caused by the gases used or generated in the experiment can be significantly reduced. As a result, the range of experiments that can be performed on the experimental bench without using a draft chamber is widened and the working efficiency is improved. Further, when the gas above the working space is sucked from the pipe 20 as in Example 3, both the gas with a large specific gravity and the gas with a small specific gravity can be satisfactorily removed from the working space, and the reliability of suppressing environmental degradation is higher. In particular, when a valve mechanism or the like is used and the ratio of the suction of the gas above the working space from the pipe 20 and the suction of the gas below the working space from the pipe 13 can be adjusted, it is possible to easily and appropriately remove according to the amounts of various gases used or generated in the experiment. Furthermore, by providing the suction port 8 on the work table 1, a dry scrubber 9 can be installed inside the base 3 below the work table 1, which was the empty space of the conventional experimental bench, so that space can be saved. These tendencies are generally the same regardless of which of the door portions 5a, 5b, 6a, 6b is open. This experimental bench with a tabletop hood can be preferably adopted in laboratories in various fields such as biotechnology, pharmaceuticals, and semiconductors.

Explanation of Reference Numerals

[0029] 1 Work table 1a Main body 1a1, 1b1 Long hole portions 1a2 Communication hole 1b Central portion 1c Suction plate 2 Hood 3 Base 4 Top plate portion 5 Front plate portion 5a, 5b, 6a, 6b Door portions 6 Rear plate portion 7 Side plate portion 8 Suction port 9 Dry scrubber 10a, 10b Downstream duct 11 Elbow 12 Round duct 13 Pipe 14 Suction device 15a, 15b Casing 16 Parts filter 17a, 17b Prefilter 18 Receiving plate 19a, 19b Receptacle 20 Pipe 21 Beaker A Short side direction B Long side direction G Gas

Claims

1. A flat work table on which experiments are conducted, a hood located above the work table, and a base located below the work table, The hood can seal the working space on the work table, The hood has an openable and closable door, The work table is provided with a suction port that opens toward the inside of the base, The suction port is connected to a suction device via the inside of the base, and a laboratory bench with a desktop hood is characterized in that.

2. The laboratory bench with a desktop hood according to claim 1, further comprising a pipe attached to the top plate portion of the hood, connected to the suction device, and communicating with the working space.

3. The pipe attached to the top plate portion of the hood incorporates a valve mechanism, and the valve mechanism can adjust the ratio of the gas flow rate sucked from the pipe to the gas flow rate sucked from the suction port. The laboratory bench with a desktop hood according to claim 2.

4. A dry scrubber is provided inside the base, positioned between the suction port and the suction device. The laboratory bench with a desktop hood according to any one of claims 1 to 3.

5. The planar shape of the work table is substantially rectangular, and the work table includes a suction plate located at the center in the short side direction and extending in the long side direction, and a plurality of the suction ports are provided on the suction plate. The laboratory bench with a desktop hood according to any one of claims 1 to 3.

6. The suction device has a fan with an air volume of 1200 m 3 / h or more and 3000 m 3 / h or less. The desktop experimental table with a hood according to any one of claims 1 to 3.

7. The opening ratio of the suction port in the work table is 20% to 80%. The laboratory bench with a desktop hood according to any one of claims 1 to 3.

Images