JP4367922B2 - 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 an opening formed in the front surface and forming an interior as a work space, and an exhaust means for sucking and removing air from the work space. The exhaust means removes air inside the main body. By exhausting constantly, toxic gases generated in the main body are prevented from leaking into the room.

However, in the configuration in which the air inside the main body is only sucked by the exhaust means, for example, when the operator is standing in front of the opening or placing devices in front of the main body, the opening is partially blocked, At the blocked portion, the intake air flow is interrupted and air stagnation, vortex flow, and turbulence are generated, and in some cases, toxic gases may leak into the room. Therefore, Patent Documents 1 and 2 describe that toxic gases are blown off to the back of the main body by blowing air from the front end of the work table toward the back of the main body.
JP-A-2-273551 International Publication WO 03/024631 A1

  By the way, in the draft chamber, the flow of air inside the main body and the inflow of room air into the main body are closely related, and in order to smoothly discharge harmful air inside the main body (work space), It can be said that it is important to control the wind direction so that the inflow of the indoor air into the air flows smoothly and the inflowing air becomes a flow that contributes to the elimination of harmful air.

  More specifically, in a push-pull type draft chamber equipped with exhaust means and forced air blowing means as disclosed in Patent Document 1, analyzing the mechanism of indoor air flowing into the main body, the inside of the main body is sucked by the exhaust means. There is an inflow due to a pulling action due to negative pressure and an inflow due to air being pulled by a jet stream by a blowing means (this is also a kind of negative pressure action), but by using two mechanisms effectively It can be said that it is important to devise so that the air flows smoothly into the main body and efficiently eliminates harmful air.

Further, not limited to forced air means is always necessary, but obtain Ri mower if sufficient only exhaust means according to activity, also the case, to leave to be able to demonstrate the ability of the exhaust means to the full preferable.

  The present invention was made based on such an idea, and the basic principle of providing forced air blowing means to blow off toxic gases in the main body to the back of the main body follows the idea of Patent Documents 1 and 2, It is an object of the present invention to provide a draft chamber that is improved.

  The inventor of the present application conducts an experiment on the configuration of Patent Documents 1 and 2 in which an air inlet is provided at the front end of the workbench, while focusing on the aerofoil described in, for example, Japanese Patent No. 3326306, completes the present invention. I came to let you.

That is, the invention of claim 1 is a main body that forms an opening on the front surface and forms an interior as a work space, and a door that is arranged to be movable up and down on the front surface to close the opening of the main body, An exhaust means for sucking and removing air in the work space, and a lower end of the work space forms a work table, the main body at the lower end of the opening of the main body The bar member extending in the front opening direction is disposed with a gap through which air passes between the bar member and the lower end of the door in the lowered state and between the bar member and the work table. The bar member is provided with an air outlet that ejects air toward the back of the main body.

The bar member is an airfoil that guides the wind direction so that the air sucked into the work space from the opening by the exhaust means is directed in the depth direction within the main body, and the airfoil has a thick front end and a rear end. It is a substantially teardrop-shaped hollow shape that is thinned as it goes, and is formed so as to have a round shape, and the aerofoil has an opening for the aeration port .

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the left and right opening edges extending vertically in the main body are formed of hollow columns, and air is directed to the left and right columns toward the back of the work space. There is a fumarole that blows out.

  By the way, even when a blow port is provided at the front end of the workbench as in both patent documents, air is drawn from the outside of the main body to the inside due to the air flow ejected from the blow port, in this case, Only the air above the fumarole is drawn. For this reason, it can be estimated that the ratio of the air drawn from the outside of the main body to the inside by the air ejected from the air outlet is small.

On the other hand, in the present invention, there are gaps through which air passes between the bar member provided with the air outlet and the lower end of the door in the lowered state and between the bar member and the work table . For this reason, air flows into the main body from both the upper and lower sides of the bar member due to the air flow ejected from the bar member. For this reason, the external air efficiently flows into the main body using the jet stream effectively. It is possible to improve the straightness of the jet stream.

  As described above, according to the present invention, it is possible to prevent the generation of vortex or turbulent flow near the opening portion by combining the ability to efficiently flow in the external air and the ability to improve the straightness of the jet stream. The performance of the draft chamber can be improved significantly.

  Further, in the configurations of Patent Documents 1 and 2, since the fountain flows toward the back along the upper surface of the workbench, for example, even if small experimental instruments are placed on the workbench, the fountain collides with the instruments. Although there is a strong possibility that the flow changes and in some cases the wind direction is reversed, in the present invention the jet is at a height higher than the front end of the workbench, so even if a small object is placed on the workbench There is also an advantage that it can be prevented or suppressed from being affected.

  Further, when configured as in claim 2, since the aerofoil originally provided with a function of imparting directivity to the inflowing air is used as the squirting means, the flow of the air sucked into the main body is made smoother. In addition, the function of imparting directivity to the wind direction is further enhanced, which is particularly suitable.

  Further, depending on the work contents, there is a case where it is not necessary to eject the jet stream into the main body. Since the flow is controlled so as to go to the inner part of the main body, the exhaust means can be fully used.

  If it comprises like Claim 3, since the harmful air which stayed in the right-and-left inner side part of a main body can be forcedly scavenged, the capability of a draft chamber can be improved further.

  Next, an embodiment of the present invention will be described with reference to the drawings.

(1). First embodiment (FIGS. 1 to 8)
1 to 8 show a first embodiment. First, an outline will be described with reference to FIGS. 1 is a perspective view of the entire draft chamber, FIG. 2 is a front view, and FIG. 3 is a sectional view taken along line III-III in FIG.

  The draft chamber includes a main body 1 having a front surface opened and a work space S formed inside. The main body 1 includes left and right side plate portions 2 and a back plate 3. The lower end of the work space is defined by the work table 4, and the upper end of the work space S is defined by the ceiling plate 5 and the translucent plate 6. The front end of the side plate portion 2 is composed of a column (front frame) 7.

  An exhaust pipe 8 is connected to the ceiling plate 5 as an example of an exhaust means, and an exhaust pipe 9 is connected to the exhaust pipe 8. Needless to say, the exhaust pipe 9 is connected to a suction source such as a vacuum pump or a suction fan.

  The upper part of the opening on the front surface of the main body 1 is closed with a glass window 10, and a door 11 is disposed below the glass window 10 so as to be movable up and down. The door 11 has a structure in which a plurality of glass plates (transparent plates) 13 are attached to a frame body 12 having a quadrangle in a front view, and can be raised to the near side of the glass window 10. In addition, it is also possible to attach a some door so that raising / lowering is possible.

  The glass window 10 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 2. An openable / closable inspection panel 14 is disposed above the glass window 10. The glass window 10, the door 11, and the inspection panel 14 are attached to the left and right columns 7 of the side plate portion 2.

  A back panel 16 extending in parallel with the back plate 3 is disposed in the back of the work space S, and a ventilation space 17 is vacant between the back panel 16 and the back plate 3. In addition, an inclined guide plate 18 that is forwardly inclined in a side view is disposed in the upper portion and the rear portion of the work space S. Although details are omitted, the back panel 16 is divided into a plurality of parts, and is drawn into the ventilation space 17 from between the adjacent back panels 16. A lamp 19 is disposed above the translucent plate 6.

  As shown in FIG. 3, the work table 4 includes a top plate 20 that occupies most of the work table 4, and a front guide body 21 is disposed at the front end of the top plate 20. The front portion of the top plate 20 is supported by a hollow rectangular stay 22, and a channel-shaped front duct (edge member) 23 is disposed on the lower surface of the front guide body 21. In addition, although the work table 4 of this embodiment is a flat top plate method, it is also possible to use a work table of a sink method or a hook-shaped method.

FIG. 3 shows a state in which the door 11 is lowered to the lower limit, and a certain amount of space is left between the door 11 and the top plate 20 in this state. Further, an airfoil 24 as a bar member is disposed between the door 11 lowered to the lower limit and the front guide body 21. The aerofoil 24 is connected (connected) to the left and right struts 7 of the side plate 2.

While the airfoil 24 is formed in a hollow shape, a blower fan 25 is disposed in an appropriate part of the main body 1 such as a space below the top plate 20, and air is supplied from the fan 25 to the airfoil 24 and the front guide body. The air is sent to the work space S. Further, description will be made with reference to FIG.

  4 is a sectional view taken along the line IV-IV in FIG. 2, FIG. 5 is a schematic perspective view showing the relationship of the main members, FIG. 6 is a perspective view showing the air supply system, and FIG. 7 is a sectional view taken along the line VII-VII in FIG. FIG. 8 is a cross-sectional view showing the relationship between the door 11 and the column 7.

  As shown in FIG. 4, the column 7 of the side plate portion 2 is formed into a hollow shape by light metal extrusion, and has two front and rear grooves 26 on opposite surfaces, along the groove 26 on the front side. The door 11 is raised and lowered. Further, the front end portion of the support column 7 has a curved surface that curves gently toward the work space S (for smoothing the inflow of air to prevent vortex and turbulence).

  Further, a step 7a projecting inward is formed in a portion of the support 7 closer to the front side than the groove 26 on the front side, and side blow holes 27 are formed in the step 7a at appropriate intervals in the vertical direction. . The group of the side blast holes 27 is formed in a range that opens in a state where the door 11 is lifted up. The support column 7 is closed with a plug 28 so that air does not leak outside (see FIG. 5).

  As shown in FIG. 5 and FIG. 7, a hose 29 is connected to the air outlet of the fan 25, and the hose 29 is connected to the column 7 through a joint 30 that penetrates the stay 22 and the front duct 23. .

  As shown in FIG. 7, the aerofoil 24 is formed in a substantially teardrop-shaped hollow that is thick at the front end and narrows thinly toward the rear end, and tilted forward in a side view. It has become. Moreover, in order to make air resistance as small as possible, it is rounded as a whole.

  The left and right ends of the aerofoil 24 communicate with the inside of the support column 7 and, as shown in FIGS. 4 and 1, the aerofoil 24 is formed with a large number of front blow holes 31 opened rearward at appropriate intervals on the left and right. ing. The aerofoil 24 is connected to the support column 7 through a sealing material or a joint.

  As shown in FIG. 7, the front guide body 21 is hollow and its upper surface is curved with a gentle curvature so as to increase gradually from the front end toward the rear. This is to allow air to flow smoothly. The rear end of the front guide body 21 has a bowl shape, and a slight gap is left between the front end of the top plate 20. Of course, the gap can be eliminated as shown by a one-dot chain line in FIG.

Incidentally, the front guide member 21 Ri also der providing the front squirting holes rearward opening, in this case, it takes in air from the fan 25 to the inside of the front duct 23, the front guide member 21, the front duct 23 A communicating air hole may be formed (therefore, the joint surface between the front guide body 21 and the front duct 23 needs to be sealed so as not to leak air).

  The horizontal lower frame 12a constituting the frame 12 of the door 11 is hollow and is curved with a gentle curvature so as to go backward as it goes to the lower end. In addition, a hollow handle 32 is provided at the lower end of the door 11, but this handle 32 is substantially teardrop-shaped so that the upper part is thick and narrows toward the lower end, and is tilted forward in a side view. It is in a shape.

  As shown in FIG. 8A, the door 11 includes a guide roller 33 that fits in the groove 26 on the near side formed in the column 7. Further, the frame body 12 of the door 11 is close to the stepped portion 7a of the support column 7. Therefore, the group of the side blast holes 27 is blocked by the frame body 12 at the 13 frame body portions of the door 11, and the opening is opened. In the portion, the jet stream is jetted from the side jet hole 27 toward the work space (a slide seal material may be provided to tightly close the side jet hole 27 without impairing the elevation of the door 11). As shown in FIG. 8 (B), it is also possible to provide a side blow hole 27 in a portion inside the door 11.

  In the above configuration, the air pressure-fed by the fan 25 is introduced into the support column 7 through the hose 29 and is ejected into the work space S from the side injection hole 27 of the support column 7 and the front injection hole 31 of the aerofoil 24. The air ejected from both the fusible holes 27 and 31 is set so as to be directed substantially in the horizontal direction.

  Then, air is drawn from the upper and lower sides of the airfoil 24 into the work space while being drawn by the jet stream from the airfoil 24. Therefore, the straightness of the jet stream can be secured, and the opening portion It is possible to effectively suppress the retention of harmful air in the vicinity. Further, when it is not necessary to drive the fan 25, the pulling action by suction from the exhaust duct 23 can be fully exhibited by the airfoil 24.

  In addition, when the lower frame 12a and the handle 32 of the door 11 are formed hollow as in the present embodiment, it is also possible to provide an air hole in the lower frame 12a and / or the handle 32 (in this case, the lower It is necessary to supply air to the frame 12a or the handle 32 with a flexible hose). It is also possible to use a combination of providing an air hole in the lower frame 12a or the handle 32 of the door 11 and providing an air hole in the aerofoil 24 or the front guide body (or the like) 27.

  As the opening of the door 11 increases, the flow rate of the incoming air decreases, and harmful air tends to stay in the vicinity of the opening. Therefore, it can be said that it is beneficial to provide an air outlet in the lower frame 12a and the handle 32 of the door 11. .

(2). Other embodiments (FIGS. 9 to 10)
By the way, when air is pumped from the fan 25 to the airfoil 24, the longer the length of the pipe (hose), the greater the air flow resistance and the greater the energy loss. Therefore, it is preferable that the air supply means such as a fan is as close as possible to the airfoil 24.

  Therefore, in the second embodiment shown in FIG. 9, a small fan 25 such as a cross flow fan is arranged inside the stay member 22, and in the third embodiment shown in FIG. A fan 25 such as a turbo fan is arranged inside. For this reason, it is possible to efficiently blow air with no loss of air supply.

  Note that such a fan arrangement can also be applied to a type in which fumarole is ejected from the front end of the work table.

(3). Others The present invention can be embodied in various ways other than the above embodiment. For example, compressed air can be used as an air supply source for ejecting air. Further, in addition to the jetting from a bar member such as an airfoil as in the present invention, it is also possible to jet from the front end of the work table.

It is a perspective view of the whole draft chamber. It is a front view of a draft chamber. FIG. 3 is a sectional view taken along line III-III in FIG. 2. FIG. 4 is a sectional view taken along line IV-IV in FIG. 2. It is a schematic perspective view which shows the relationship of a main member. It is a perspective view which shows an air_supply system. FIG. 7 is a sectional view taken along the line VII-VII in FIG. 4. It is sectional drawing which shows the relationship between a door and a support | pillar. It is a figure which shows 2nd Embodiment. It is a figure which shows 3rd Embodiment.

DESCRIPTION OF SYMBOLS 1 Main body S Work space 2 Side plate part 4 Work table 7 Strut 8 Exhaust cylinder 11 Door 20 Top plate 21 Front guide body 22 Stay member 23 Front duct 24 Aerofoil 25 Fan 27 Side air hole 31 Front air hole

Claims (3)

A main body that forms an opening in the front surface and forms an internal work space; a door that is disposed on the front surface of the main body so as to close the opening; and air in the work space is removed by suction. An exhaust means, and a draft chamber that forms a lower end of the work space with a workbench,
At the lower end of the opening of the main body, a bar member extending in the frontage direction of the main body is between the bar member and the lower end of the door in the fully lowered state, and between the bar member and the work table. Each is arranged with a gap through which air passes,
The bar member is provided with an air outlet that ejects air toward the back of the main body.
Draft chamber. The bar member is an airfoil that guides the wind direction so that the air sucked into the work space from the opening by the exhaust means is directed in the depth direction within the main body, and the airfoil has a thick front end and a rear end. It is formed in a substantially teardrop-shaped hollow shape that is thinly narrowed as it goes and has a round shape as a whole, and the aerofoil has an opening of the fumarole,
The draft chamber according to claim 1. The left and right opening edges extending vertically in the main body are configured with hollow struts, and the right and left struts are provided with air vents that eject air toward the back of the work space.
A draft chamber according to claim 1 or 2.

Images