JP5035868B2 - Draft chamber - Google Patents

Description

  The present invention relates to a draft chamber (fume hood, clean bench).

The draft chamber includes a main body having a work space in which an opening is formed, and an exhaust unit that sucks and removes air in the work space. By constantly exhausting air in the work space by the exhaust unit, Toxic gases generated in the work space are prevented from leaking outside .

However, in a configuration in which air is only sucked by the exhaust means, for example, when an opening is partially blocked by an operator standing in front of the opening or placing devices in front of the main body, the blocking is performed. The airflow from the opening is blocked at the separated portion, and air stagnation, vortex flow, and turbulent flow are generated. In some cases, toxic gases may leak to the outside .

Therefore, Patent Document 1 blows off toxic gases to the back of the main body by blowing air from the end (front end) on the side where the opening of the work table is provided toward the back of the main body. The configuration is described. More specifically, the front side of the inner wall surface of the main body (rear), the inhibitory flow wall substantially along the entire surface of the wall is provided, the exhaust passage between the inhibitory flow wall and the inner wall surface, inhibitory flow wall The air is taken into the exhaust passage from the lower end of the gas. The air ejected from the front end portion travels to the back side (rear side) so as to strok along the upper surface of the work table, rises through the exhaust passage, and is exhausted by the exhaust duct disposed above. Is done. In other words, the air ejected from the side where the opening is provided is configured to send toxic gases to the inner part and guide them upward along the wall surface to exhaust them.

In addition, in the patent document 2 or the like, the present applicant arranges a front guide body that blows air toward the back of the main body at the lower end of the opening of the work table, and further above the front guide body. There is disclosed a configuration in which an airfoil is provided at an interval, air is ejected from the airfoil toward the back, and air flows into the opening from above and below the airfoil. Thereby, the residence of toxic gases near the opening is effectively suppressed.
International Publication WO 03/024631 Pamphlet JP 2005-288241 A

  By the way, the draft chamber includes not only a single-sided opening type in which an opening is provided only on the front side, but also a double-sided opening type in which openings are provided on both the front and rear sides. Since the chamber can be used from both the front and back sides, there is an advantage that a limited space such as a laboratory can be used effectively.

  However, in such a double-sided opening type draft chamber, as a matter of course, since another opening is provided on the opposite side of the opening, the front end portion provided with the opening as in Patent Document 1 is provided. It is not possible to employ a configuration in which toxic gas is pushed to the rear side by the air ejected from and guided upward along the wall surface. Therefore, even in a double-sided opening type draft chamber, there has been a demand for a configuration in which toxic gases are reliably exhausted without leakage. In addition, the organic solvent gas heavier than air tends to stay at the bottom of the work space, regardless of whether it is a single-sided opening type or a double-sided opening type, and a method for effectively eliminating this has been desired.

  In order to meet the above-mentioned demand, the present invention is based on the configuration described in Patent Document 2 and is further improved to achieve a draft chamber excellent in discharge and removal of toxic gases. is there.

To achieve the above object, a draft chamber in the invention of claim 1 includes a main body forming an opening in the front surface of the outer peripheral portion sac Chi one surface of a generally rectangular plan view of the working space as a front, and an exhaust means for sucking and removing air in the working space upwards in at least the lower end of the circumference and the front point of the opening and its opposite rear portion of the work space, the Arranged so as to face each other along the bottom surface of the work space, and the air blown backward from the air vent provided at the front of the work space and provided at the rear of the work space It is set so that the air blown forward from the air outlet collides with the front and rear central portions of the work space and flows upward.

According to a second aspect of the present invention, in the draft chamber according to the first aspect, a large number of the front and rear vent holes are provided along the opening direction of the opening.

The invention according to claim 3, in the draft chamber according to claim 1 or 2, together with the opening in the rear surface of the body is al provided, in plan view the central of the upper portion of the body and provided with the exhaust means, further, it said four corners of the main body is provided with a support column extending vertically, wherein the lower end portions of both openings, the main jet ports are provided is the gas nozzle, the strut the auxiliary gas nozzle for ejecting air toward the working space has set vignetting, initial velocity of the air ejected from said main jet ports is 1 initial velocity of the air ejected from the auxiliary jet ports .5 to 2 times .

According to the invention described in claim 1, poisonous gases staying in the work space, and merges are collected at a substantially central portion of the work space rides on the air flow ejected from two directions opposed to the front and rear As it is, it becomes an ascending current and is removed toward the exhaust means. That is, even if there is no wall surface for guiding to the exhaust means as in the prior art, an upward air flow for guiding to the exhaust means is generated in the work space, and the toxic gases are surely put on this air flow. Can be removed.

Further, provided at least a lower end portion of the front and rear of the injection gas port working space, because they constitute along the bottom surface of the working space to flow air, even the specific gravity heavy organic solvents and toxic gases , it is possible to remove out exhaust air together with from no injection gas ports be retained on the bottom of the working space.

  According to the third aspect of the invention, in addition to providing the main jet port at the lower end portion of the opening, the auxiliary jet ports are provided at the four corner columns, so that the air from the auxiliary jet port is supplied from the opening. It is possible to form an air flow that efficiently and surely guides the toxic gases to the exhaust means by assisting the air from the main gas outlet.

  In addition, since the initial velocity of the air ejected from the auxiliary vent is set smaller than the initial velocity of the air ejected from the vent, the air from the auxiliary vent is It is possible to prevent the flow from being disturbed.

  Embodiments of the present invention will be described below with reference to the drawings. 1 is a perspective view of the entire draft chamber, FIG. 2 is a front view, FIG. 3 is a sectional view taken along the line III-III in FIG. 2, FIG. 4 is an enlarged sectional view in the vicinity of the fumarole, and FIG. FIG. 6 is a cross-sectional view taken along line -V, and FIG. 6 is a plan view schematically showing the flow of air.

The main body 1 of the draft chamber is formed with a work space S having a substantially rectangular shape in plan view. Openings 2 are provided on the front surface and the rear surface of the work space S, respectively. The main body 1 includes left and right side plate portions 4 and 5, the lower end of the work space S is defined by a work table 6, and the upper end of the work space S is defined by a ceiling plate 7. At the four corners of the work space S (front and rear ends of the side plate portions 4 and 5), respectively, columns (front frames) 9 are formed. Here, for convenience, the X direction (frontage direction) shown in FIG. 1 will be described as the left-right direction and the Y direction will be described as the front-rear direction.

One side plate portion 4 is configured by fitting a glass plate (translucent plate) 10 in the center of the frame body 4a so that the work space S can be seen from the outside of the side. While the other side plate portion 5 is constituted by having no plate-like member light-transmitting mechanism for raising and lowering the later-described door 14 (not shown) is incorporated. Of course, the side plate portion 4 may also be entirely constituted by a plate-like member having no translucency.

At the center of the ceiling surface 7 that is substantially rectangular in plan view (on the central axis O shown in FIG. 3), as an example of exhaust means, an exhaust pipe 12 is connected to a suction source such as a vacuum pump or a suction fan. A cylinder 11 is arranged. Before and after sandwiching the stack 11 above the ceiling plate 7 is disposed, each lamp 17, a part of the ceiling plate 7, to transmit the light of the lamp 17 downwardly, the transparent plate It is attached.

The upper portion of each opening 2 of the front and rear that put the body 1 are respectively closed by the glass window 13, below the glass window 13 is disposed the door 14 vertically movably. The door 14 has a structure in which a plurality of glass plates (transparent plates) 16 are attached to a rectangular frame 15 in front view in a left-right sliding manner, and can be raised to the near side of the glass window 13. In addition, it is also possible to attach a some door so that raising / lowering is possible.

  The glass window 13 has a structure in which a transparent plate is attached to a rectangular frame, and is usually fixed to the left and right side plate portions 4 and 5. An openable / closable inspection panel 32 is disposed above the glass window 13. The glass window 13, the door 14, and the inspection panel 32 are attached to the columns 9 before and after the side plate portions 4 and 5.

  As shown in FIG. 3, the work table 6 includes a top plate 18 occupying most of the work table 6, and a front guide body 19 is disposed at each of a front end portion and a rear end portion of the top plate 18. Further, the front and rear portions of the top plate 18 are supported by a hollow square stay 20, and a channel-shaped front duct (edge member) 21 is disposed on the lower surface of the front guide body 19. In addition, although the work table 6 of this embodiment is a flat top plate system, it can also be a work table of a sink system or a slat-like system.

  3 and 4 show a state in which the door 14 is lowered to the lower limit. In this state, a certain amount of space is left between the lower end of the door 14 and the top plate 18. Further, an aerofoil 22 as a bar member is disposed between the lower lower limit door 14 and the front guide body 19. The aerofoil 22 is connected (connected) to the support 9.

  The front guide body 19 is an extruded product made of light metal or synthetic resin. The front guide body 19 is hollow and has an upper surface formed in a curved shape with a gentle curvature that gradually increases from the front end toward the rear. This is to allow air to smoothly flow into the work space S from the outside. Further, due to the curved shape, the upper end of the rear surface of the front guide body 19 is slightly higher than the upper surface of the top plate 18, but the rear surface of the front guide body 19 that is higher than the top plate 18 A plurality of main air inlets 25 for injecting the air that has flowed into the front guide body 19 toward the work space S are provided in the left-right direction (the opening direction of the opening) with a space therebetween. That is, the main blow holes 25 are respectively provided at portions facing each other across the work table 6. A flange portion 26 that extends toward the work space S is integrally formed at the upper end of the rear surface of the front guide body 19, and the air ejected from the main air outlet 25 is formed in the work space S by the flange portion 26. It is surely guided to the back side along the bottom surface. You may comprise so that the air ejected from the main vent 25 may be discharged a little upward toward the back side. Moreover, you may provide the main blowing port 25 in the shape of a long slit along the left-right direction (front-end | tip direction of an opening part).

  The front guide body 19 and the front duct 21 are sealed and overlapped. The front guide body 19 has a communication hole 27 that communicates with the front duct 21, while the front duct 21 has a joint 28 interposed therebetween. The hose 24 is connected. The left and right ends of the front duct 21 are closed.

  As shown in FIG. 5, the support column 9 is formed of a light metal extruded product and is formed in a hollow shape, and two front and rear grooves 29 are provided on opposite surfaces across the opening 2. The door 14 moves up and down along the groove 29. Further, the front end portion of the column 9 is a curved surface that curves gently toward the work space S. This takes into account the smooth flow of air from the outside into the working space S to prevent vortex and turbulence. In a portion of the support column 9 on the nearer side than the groove 29 on the near side, auxiliary jet ports 31 are formed at appropriate intervals along the vertical direction in the stepped portion 30 protruding inward (over the entire height of the opening). Can also be provided). Since the support columns 9 are arranged at the front and rear end portions of the side plate portions 4, 5, air is jetted from the auxiliary jet ports 31 at the four corners of the work space S toward the center portion of the work space S.

Wind fan 23 feeding the proper site below the top plate 18 of the main body 1 is arranged, takes in room air the body 1 is installed with the fan 23, the hose 24 and the air , and is configured to air respectively to the front guide body 19 after the front via the front duct 21. Further, the blower fan 23 is configured to also air inside the standoff 9 via a hose (not shown).

  The air sent to the front guide body 19 is jetted from the main jet port 25 toward the center of the work space S at the initial velocity V1 (see arrow A in FIGS. 3, 4 and 6). The initial velocity V1 is set to such a magnitude that the air jetted from the main jetting holes 25 before and after the work table collides with certainty. The air ejected from the front and rear main air outlets 25 collides in the vicinity of the central axis O shown in FIG. 3 and merges, and ascending air current (via the exhaust cylinder 11) by the exhaust means (via the exhaust cylinder 11) B), and is sucked and removed by the exhaust cylinder 11 arranged vertically above the central axis O.

  On the other hand, the air sent to the support column 9 is ejected from the auxiliary jet port 31 toward the center of the work space S at the initial velocity V2 (see arrow C in FIGS. 5 and 6). Since a plurality of auxiliary jet ports 31 are provided along the support column 9 in the vertical direction, the air from the auxiliary jet ports 31 suppresses toxic gases leaking outside from the work space S. It acts and can greatly improve the leakage prevention effect. The direction of the air blown out from the auxiliary blower port 31 is directed toward the central portion of the work space S, but by making it blow out slightly closer to the opening 2 than this, the exposure from the opening 2 described above is performed. The effect to prevent can be heightened.

  According to the experiment conducted by the present applicant, the initial velocity V1 of the air from the main nozzle 25 is set to about 1.5 to 2 times the initial velocity V2 of the air ejected from the auxiliary nozzle 31. It was confirmed that the discharge performance was obtained. By setting the momentum of the air ejected from the auxiliary air outlet 31 to be weaker than that of the air from the main air outlet 25, the air from the auxiliary air outlet 31 is moved toward the exhaust pipe 11 from the main air outlet 25. It is presumed that a good air flow excellent in exhaustability could be generated by compensating for this without disturbing the flow. Moreover, since the auxiliary jet port 31 is provided not only at the lower part but also at the upper part of the support column 9, if the air ejected from the auxiliary jet port 31 is too strong, the upward air flow toward the exhaust means (exhaust cylinder 11) is obstructed. Although there is a possibility, ascending air current can be stably generated by setting to the ratio of the initial speeds V1 and V2 described above.

  The aerofoil 22 provided above the front guide body 19 and spaced apart from the front guide body 19 is a hollow member, but the outer shape of the aerofoil 22 is substantially tearless in a side view as the front end portion is thicker in the vertical direction and becomes thinner toward the back side. It is in the shape of a drop and is inclined so that the front end side is lowered. Moreover, it is rounded as a whole, and the air resistance of the air entering the work space S from the outside is made as small as possible. Thus, similarly to the airfoil described in Patent Document 2, since air flows from the upper and lower sides of the airfoil 22 into the opening 2, the retention of air near the opening 2 is suppressed. The straightness of the air jetted from the jet port 25 is improved. Moreover, you may add the structure which forms an airfoil in hollow shape and injects air also from an airfoil.

  According to the above configuration, the main body 1 has the openings 2 and 2 on the front and rear sides thereof, but air is directed toward the work space S from before and after the work table 6 on the lower side of each opening 2. Since it is configured so that the jetted air and the jetted air collide with each other to generate an updraft, toxic gases, organic solvents, etc. staying around the upper surface of the workbench 6 (bottom surface of the work space S) are removed. Then, they can be gathered and raised near the center (center axis O) of the work table 6 and efficiently guided to the exhaust tube 11 for exhaust removal. In addition, the flow of air from the auxiliary blow holes 31 of the pillars 9 at the four corners of the workbench 6 can confine the work space S in the work space S while suppressing leakage of toxic gases and organic solvents to the outside. Since the air flow from the main fumarole 25 is compensated for, the reliability of exhaust of toxic gases and the like can be improved.

The present invention can be embodied in various ways other than the above embodiment. For example, in the above SL embodiment, had provided the main jet ports 25 in the front guide member 19, the position of the main jet ports 25 a gas nozzle of claim is not limited to this, the working space You may provide in the other member arrange | positioned at the lower end side of S. Furthermore, the position of the opening 2 is provided in the working space S, not limited to the two surfaces of the front and rear shown in the above embodiment, the draft chamber having an open mouth only one side (front surface) of the outer peripheral portion of the work space S it can also be applied to.

It is a perspective view of the whole draft chamber. It is a front view of a draft chamber. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. It is an expanded sectional view near a fumarole. FIG. 5 is a cross-sectional view taken along line VV in FIG. 2. It is a top view which shows the flow of air typically.

DESCRIPTION OF SYMBOLS 1 Main body 2 Opening part 4, 5 Side plate part 6 Work table 9 Support | pillar 11 Exhaust pipe 14 Door 19 Front guide body 23 Blower fan 25 Main jet port 31 Auxiliary jet port

Claims (3)

A body forming the opening peripheral portion sac Chi one surface of a generally rectangular plan view of the working space to the front as a front, and an exhaust means for sucking and removing air in the working space above the Arranged so as to face each other at least at the lower end of the periphery of the work space , and at the front part of the location of the opening part and the rear part on the opposite side thereof, to blow out air along the bottom surface of the work space. The air ejected backward from the air outlet provided in the front part of the work space and the air ejected forward from the air outlet provided in the rear part of the work space are formed at the front and rear central parts of the work space. Set to collide and create an upward flow,
Draft chamber. A large number of the front and rear fumaroles are provided along the frontage direction of the opening,
The draft chamber according to claim 1. An opening portion in a rear surface of the body is al provided, wherein is provided the exhaust means in a planar view substantially center of the upper portion of the body, further, the four corners of the main body provided with a support column extending vertically And
Wherein the lower end portions of both openings, the gas nozzle is a primary gas nozzle is provided on the strut, the auxiliary gas nozzle for ejecting air toward the working space has set vignetting, the main jet The initial speed of the air ejected from the mouth is set to 1.5 to 2 times the initial speed of the air ejected from the auxiliary air outlet ,
Draft chamber described 請 Motomeko 1 or 2.

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