JP2005288243A - Draft chamber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a draft chamber enhancing air scavenging performance while suppressing air conditioning cost. <P>SOLUTION: A body 1 of this draft chamber is provided with an exhaust cylinder for sucking/removing internal air and a fan 25 for jetting air from an opening edge. A suction port 26 is provided on an inner side surface of the body, the whole or a part of air jetted into the body 1 is taken-in from the inside of the body by connecting the suction port 26 and the fan 25 by a conduit 29, and the air is jetted from the front end of the body into the body. Since conditioned air used for jetting can be eliminated or reduced, the air conditioning cost can be suppressed. Then, when the exhaust ability is constant, since an amount of air flowing into the body caused by forcedly jetting it can be prevented or suppressed from being reduced, reduction of flowing-in speed of air at the opening can be prevented or suppressed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

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 a configuration in which the air inside the main body is only sucked by the exhaust means, for example, when an operator stands in front of the opening or places devices in front of the main body and the opening is partially blocked, The intake flow is blocked at the blocked portion, and air stagnation, vortex flow, and turbulence are generated. In some cases, toxic gases may leak into the room.

Therefore, in Patent Documents 1 and 2, it is possible to blow off toxic gases to the back of the main body by blowing air from the opening edge of the main body (for example, the front end of the work table) toward the back of the main body. Has been described.
JP-A-2-273551 International Publication WO 03/024631 A1

  By the way, air conditioning is carried out without exception in a laboratory or the like where a draft chamber is installed, and this air conditioning naturally costs (mainly electricity charges). For this reason, if indoor air is sucked by a fan or the like and blown out into the main body, conditioned air is consumed and air conditioning costs increase.

  In this regard, Patent Document 1 discloses that outside air is guided to a draft chamber by a duct, and this outside air is ejected into the main body. In this case, there is no consumption of conditioned air associated with the inhalation air, so the problem of increased air conditioning costs. However, there is another problem that it is very expensive to install a duct that guides outside air to the draft chamber.

  The present invention has been made in view of such a current situation, and the point of improving the scavenging performance by ejecting air into the main body is a draft that can suppress the air conditioning cost as much as possible while following the concept of Patent Documents 1 and 2 above. It is an object to provide a chamber.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a main body having an opening formed in the front surface to form a work space, an exhaust means for sucking and removing air in the work space, and an opening of the main body. In a draft chamber equipped with air supply means for injecting air from the edge toward the inside, air is exhausted from the main body by air or exhaust means in the main body at the front or part of the air to be injected from the air supply means It is characterized by the use of conditioned air.

  According to a second aspect of the present invention, in the first aspect, the exhaust means is provided at the upper part of the main body, while the air supply means supplies air to the lower part of the inner side surface of the main body and the rear part of the front end edge. A suction port is provided for taking in air.

  According to the present invention, in a draft chamber in which the scavenging performance is improved by using both the suction by the pulling action of the exhaust means and the blowing action by the push action by the air supply means, once inside the main body as all or part of the fuming air that performs the pushing action Since air that has entered is used, it is possible to suppress consumption of clean air in the air-conditioned room, which increases the scavenging performance of the draft chamber, resulting in increased air conditioning costs. It can be prevented or suppressed.

  By the way, when the capacity of the exhaust means is constant, when all of the air fed into the main body is taken in from the room, the amount of air flowing into the main body by the pulling action of the exhaust means is reduced by the amount of the supplied air For this reason, the flow velocity of the air flowing into the main body is lowered by the pulling action.

  On the other hand, in the present invention, for example, if all of the fumarole ejected from the air feeding means is taken in from the main body and circulated, the amount of air flowing into the main body by the pulling action does not change, and therefore the opening of the main body The flow rate of the incoming air at the section does not decrease, and the scavenging performance does not decrease due to the pulling action. When a part of the fumarole is taken in from the inside of the main body, a decrease in the inflow speed of air at the opening can be suppressed accordingly.

  If the suction action from the intake port interferes with the suction action from the exhaust means, not only the scavenging performance is lowered, but also energy is lost. In this respect, the construction as in claim 2 is preferable because there is no interference between the suction by the exhaust means and the suction by the air supply means.

  In the draft chamber, it can be said that the work in the work space is generally performed closer to the central part, and the work on the left and right side parts is rare. For this reason, the configuration as in claim 2 is preferable because it can prevent chemicals from being scattered in the intake port.

  Further, since the air jetted into the main body by the air supply means does not leak out of the main body, there is no problem even if the air inside the main body is used as the blown air, but the inside of the main body is near the inner side surface and Since there is little dirt on the air in the lower part, it can be said that the construction as in claim 2 is beneficial from the viewpoint of ensuring the cleanliness of the blown air as much as possible.

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

(1). Basic Configuration First, the basic configuration 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 (exhaust duct) 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 exhaust pipe 8 may be provided with an air volume adjusting device such as a damper.

  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. It is also possible to attach a plurality of doors so that they can be raised and lowered.

  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 aerofoil 24 as a bar member is arranged between the lower limit door 11 and the front guide body 21. The aerofoil 24 is connected (connected) to the left and right struts 7 of the side plate portion 2.

  And the ventilation fan 25 which comprises a part of the circulation means which takes in the air in a main body is arrange | positioned in appropriate parts, such as the space under the top plate 20, among the main bodies 1, and the lower part of the inner surface of the side plate part 2 and An intake port 26 is provided at a position slightly closer to the opening, the intake port 26 and the suction port of the fan 25 are connected by a conduit 28, and air in which the air in the main body and the air in the room are mixed is mixed with the fan 25 and the hose 29. Is sent to the front guide body 21 and ejected from the front guide body 21 into the work space S. Next, detailed examples of the intake part and the squirt part will be described with reference to FIGS. 4 is a cross-sectional view taken along line IV-IV in FIG. 3, and FIG. 5 is a partial cross-sectional view of the front portion of the main body 1.

(2). Description of Details The intake port (intake part) 26 includes a large number of suction holes 31 formed in the inner plate 2a of the main body 1, and a joint duct 32 surrounding the group of the suction holes 31 from the back side of the inner plate 2a. The pipe line 28 is connected to the joint duct 32.

  In this embodiment, the left and right inner plates 2a are provided with the intake ports 26. However, the intake ports 26 may be provided only on one inner plate 2a, or conversely, a plurality of intake ports 26 are provided on both or one inner plate 2a. It is also possible. Further, as shown by a one-dot chain line in FIG. 4, a protection plate 33 that prevents the liquid from scattering in the suction hole 31 may be provided.

  The arrangement position of the intake port 26 is not particularly limited, but it is not necessary to interfere with the pull action by the exhaust tube 8 and to prevent the inflow of conditioned air from the outside of the main body. It is also necessary to avoid as much as possible the points that do not interfere with the work and the effects of the scattering of liquids. Furthermore, it is important that the piping to the fan does not get in the way.

  In this respect, when the air inlet 26 is provided in the lower part of the inner side surface of the main body and slightly apart from the opening as in the present embodiment and the conduit 29 is passed through the inside of the side plate 2, all of the above requirements are met. It is clear and suitable.

  As shown in FIG. 5, the front guide body 21 is made of an extruded product made of a light alloy or a synthetic resin, and is hollow and has a gentle curvature so that its upper surface gradually increases from the front end toward the rear. It has a curved shape. This is to allow air to flow into the work space S as smoothly as possible.

  Further, the rear end of the front guide body 21 is a flange portion 21 a, and a slight gap is left between the front end of the top plate 20. A fusible hole 34 is formed in the back surface of the front guide body 21 exposed toward the work space. The front guide body 21 and the front duct 23 overlap each other in a sealed state, and a communication hole 35 communicating with the front duct 23 is opened in the front guide body 21, while the hose 29 is connected to the front duct 23 via a joint 36. Is connected. The left and right ends of the front duct 23 are closed.

  The aerofoil 24 is formed in a substantially teardrop-shaped hollow whose front end portion is thick in width and narrows toward the rear end, and is inclined in a forward tilted manner in a side view. It has become. Moreover, in order to make air resistance as small as possible, it is rounded as a whole. A handle 37 is provided on the door 11.

  In the above configuration, the air in the work space S is removed to the outside by a pulling action by sucking from the exhaust tube 8, and the work is performed by a push action (blowing action) by the positive pressure air being ejected from the blow hole 34. It is possible to prevent harmful air from staying around the upper surface of the table 4.

  And since the fumarole which makes a push action is taken in from the inside of the main body 1, the conditioned air in the room is not used for the fumarole, and the air conditioning cost can be suppressed (a part of the fumarole of the main body 1 can be reduced). Needless to say, you can get it from the inside.)

  By the way, the indoor air flows into the inside of the main body 1 from the opening due to the pulling action by the exhaust tube 8. Therefore, when the exhaust amount by the exhaust cylinder 8 is Q0, the amount of air flowing into the main body 1 from the opening is Q1, and the amount of the fumarole ejected into the main body from the fumarole 34 is Q2, If Q0 is constant, Q1 decreases by Q2 and becomes Q1 = (Q0-Q1). As a result, the flow velocity at the opening is reduced compared to the case where no air supply means is provided. To do.

  On the other hand, when the fumarole is taken from the inside of the main body as in the present invention, the state of Q1 = Q0 is maintained, so there is no decrease in the flow velocity at the opening, and therefore the scavenging performance by suction from the exhaust tube 8 is improved. There is no reduction.

  As shown in FIG. 6, in addition to or instead of blowing from the front end portion of the work table 4, side blowing ports 38 may be provided in the left and right support columns 7, and the inside of the main body may be injected from the support columns 7. .

  Further, instead of providing the intake port inside the main body 1, it is also possible to connect the exhaust cylinder 8 (or the exhaust pipe 9) and the fan 25 by a pipe line 39 as shown by a two-dot chain line in FIG. 3. is there.

  There is no limitation on the position of the fumarole. For example, it may be provided on the aerofoil 24 or on the frame 12 or the handle 37 constituting the door 11. The arrangement position and type of the fan 25 are not limited. For example, a small fan such as a cross flow fan may be adopted and incorporated in the stay member 22.

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. 3. It is sectional drawing of the front-end part of a main body. FIG. 6 is a sectional view taken along line VI-VI in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body S Work space 2 Side plate part 4 Work table 7 Support column 8 Exhaust pipe 11 Door 20 Top plate 21 Front guide body 23 Front duct 24 Aerofoil 25 Fan 26 Inlet port 34 Fumarole hole

Claims (2)

A main body having an opening formed on the front surface and forming the inside as a work space, an exhaust means for sucking and removing air in the work space, and an air supply for ejecting air from the opening edge of the main body toward the inside A draft chamber comprising means,
The front part or part of the air ejected from the air feeding means uses air in the main body or air discharged from the main body by the exhaust means,
Draft chamber. While the exhaust means is provided at the upper part of the main body, a suction port for taking in the air supplied by the air supply means is provided at the lower part of the inner side surface of the main body and at the rear part of the front edge. ,
The draft chamber according to claim 1.

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