EP2419224A1

EP2419224A1 - Laboratory fume hood

Info

Publication number: EP2419224A1
Application number: EP10719291A
Authority: EP
Inventors: Jürgen Liebsch
Original assignee: Waldner Laboreinrichtungen GmbH and Co; Waldner Laboreinrichtungen GmbH and Co KG
Current assignee: Waldner Laboreinrichtungen GmbH and Co; Waldner Laboreinrichtungen GmbH and Co KG
Priority date: 2009-04-17
Filing date: 2010-04-16
Publication date: 2012-02-22
Anticipated expiration: 2030-04-16
Also published as: DK2419224T3; JP2012523953A; JP5719830B2; EP2419224B1; AU2010238488A1; PT2419224E; CA2757939A1; CN102395433B; US9505043B2; CN102395433A; DE102009002458A1; US20120100789A1; AU2010238488B2; WO2010119135A1; MX354298B; SG175068A1; ES2529556T3; CA2757939C; MX2011010746A

Abstract

The present invention relates to a laboratory fume hood (100) comprising a front slide (30) movably connected to a laboratory housing (60) for opening and closing the interior of the laboratory fume hood, wherein an air passage (70) is provided between the front slide (30) and a side post (10) of the laboratory housing (60) which is designed to create wall jets on the interior of the laboratory fume hood.

Description

The present invention relates to a fume hood.

Fume hoods are an integral part of laboratories. All laboratory work involving the handling of gases, vapors, suspended solids or liquids in hazardous amounts and concentrations must be carried out in laboratory fume cupboards to protect laboratory personnel.

In the past, the characteristic that indicates the safety and effectiveness of fume hoods was the so-called exhaust flow rate. In contrast to this definition, the introduction of DIN 12924 Part 1 in 1991 determined the effectiveness of fume hoods by setting a limit value for the outbreak of test gas. This limit value specifies the so-called breakout resistance of a fume hood. Although the DIN 12924 Part 1 has since been replaced by the European standard DIN EN 14175, numerous innovations in the field of fume hoods concern the optimization of energy efficiency, with which a fume hood can be operated while maintaining the standardized breakout safety. Energy efficiency is largely determined by the minimum exhaust air volume flow. Significant energy savings are thus achieved by reducing the Mindestabluftvoiumenstrorns.

To reduce the Mindestabiuftvoiumenstroms the so-called Stützstrahitechnik has been developed. When Stützstrahitechnik come wing-shaped profiles are used, which are provided on the side posts, the front edge of the trigger table top and the lower edge of the sash. In addition, supply air is passed under pressure through the side pillars designed as hollow profiles and the front edge, which is then blown out of slot-shaped openings in the withdrawal interior when the sash is partially or fully opened. After exiting the slot-shaped openings, the supply air sweeps along the bottom surface and the lateral wall surfaces of the exhaust interior to prevent accumulation of toxic gases, vapors or suspended matter in the area of the wall surfaces and bottom surface. These wall beams ensure a flow velocity in the region of the wall surfaces and floor surface which is not equal to zero, as a result of which wall friction effects are greatly reduced,

By means of these support beams, the minimum amount of exhaust air at which the escape-proof fume hood still complies with the standardized regulations could be lowered significantly when the sash was partially or fully opened. Likewise, they prevent dangerous backflow regions, since there is no stall in the area of the wall surfaces and bottom surface, in particular in the region of contour changes. An example of a fume hood equipped with support jet technology is described in DE 101 46 000 A1.

Even with fume hoods without support beam technology, i. In the case of fume hoods that are not flow-optimized, a reduction of the minimum exhaust air volume flow can be achieved by installing so-called demand-dependent air volume regulators. Since sash valves usually do not close the fume cupboards airtight, the fume hoods with the sash closed only have small openings to the laboratory space, so that only a relatively small amount Minimum exhaust air volume flow required to ensure normalized outbreak safety »These demand-controlled air flow regulators regulate the required minimum exhaust air volume flow depending on the position of the sash, which allows further energy savings even with fume hoods without support jet technology.

Further fume hoods are described in GB 2 331 358 A1, DE 103 38 284 B4, DE 295 00 607 U1 and EP 1 977 837 A1. The in GB 2 331 358 A1 described has louvers provided on its front side, through which room air is drawn into the working space of the fume hood. The side post of the trigger described in DE 103 38 284 B4 has a the side wall of the working space receiving profile element, which is spaced from the front side of the guide mechanism of the sash, room air is through the sucked slot formed by this distance in the working space. Due to the geometry of the slot, the room air exits perpendicular to the side walls in the form of free jets in the working space. In DE 295 00 607 Ul a mobile fume hood is described, which can be viewed on all sides for educational purposes. It has a front and a side slide. In the closed position of the sideshift, room air can enter the working space of the trigger through a gap between the sideshift and the worktop. The trigger described in EP 1 977 837 A1 has a hollow profile on the lower edge of the sash. This HohSprofil is provided with a passage so that room air through the hollow profile! can be sucked into the workspace of the trigger.

It is an object of the present invention to provide a fume hood in which the energy efficiency is further improved. In particular, it is an object of the present invention to provide a fume hood, which can be operated without support beam technology with a reduced minimum exhaust air volume flow while maintaining the normalized escape safety.

This object is achieved by a fume hood, which has the feature combination of claim 1

Preferred embodiments of the invention are the subject of the dependent claims 2 to 9. According to the invention, the fume hood comprises a sash movably connected to a laboratory housing for opening and closing a withdrawal interior. Between the sash and a side post of the laboratory housing, an air passage is provided, which is designed to generate wall jets in the withdrawal interior. The passage of air, even when the sash is closed, directs air into the fume cupboard interior to create wall strays that reduce wall friction effects and remove pollutants to the rear and from the fume cupboard interior. This achieves a reduction of the minimum exhaust volume flow, which has an advantageous effect on the energy balance of the fume hood,

The beneficial effect of the passage of air is not only evident in laboratory fume hoods. Even without projection of support jets into the fume cupboard interior, room air can enter the fume cupboard interior through the air passage and sweep along the walls in the fume cupboard to the wall of the fume hood. «This reduces the minimum tapping volume flow even with a fume hood without support jets.

In addition, there is another effect that affects the safety of the fume hood. Since the sash is naturally not hermetically sealed off with the trigger housing, room air flows with the front fender closed due to the suction effect of the exhaust air in the drawing room at high speed through the often located at the top and bottom of the front fender remaining openings in the deduction interior. A uniform volume flow distribution in the vent interior with closed sash is thus no longer given. The resulting vortices and the total non-directional flow lead to a prolonged refueling time of releasing pollutants in the fume cupboard interior. In the case of smoke or haze, this can lead to limited visibility of the fume cupboard by the laboratory staff. lead πal. Furthermore, pollutants may accumulate in the front area of the deduction interior, ie directly behind the Frontschϊeber in increased concentration with the risk that the pollutants can escape when opening the sash of the deduction interior.

The air gap provided between side posts and sash increases the safety of the trigger in that the inflow is equalized circumferentially at the sash, but especially in the region of the side walls of the withdrawal interior with the result that the formation of undirected and / or turbulent flow in Abzuginπenraum with closed sash is prevented. The accumulation of pollutants directly behind the sash in Abzuginπenraum is thereby prevented. The risk of breakout of pollutants with subsequent opening of the Fronschiebers is thus lowered drastically.

Since the support jet effect is also produced without support beams through the air passage or air gap, the air supply for the support beams can be switched off when the front fascia is closed, which results in a further power saving. In addition, the noise level of the fume hood is lowered by switching off the fans that feed the air to the support jet outlet openings.

Preferably, the air passage is nozzle-shaped, whereby the effect described above is further enhanced.

Further preferably, the air passage is designed such that its width increases in the horizontal direction of Abzugϊnnenraum to the exhaust external space.

According to a preferred embodiment of the invention, the geometry of the air passage is such that a hypothetical, substantially rectilinearly perpendicular to the surface of the sash extending particle or liquid flow can not pass from the deduction interior in the exhaust external space. This geometry ensures that despite the gap existing between Froπtschieber and deduction post, the primary function of the fume hood, namely the splash and splinter protection is maintained. It is important that no particles or liquids can escape from the fume cupboard to the fume hood. Ensuring this function of the trigger should be achieved by this preferred embodiment.

According to a preferred embodiment of the invention, a vertäka aligned! extending, the deduction interior facing outer edge of Rahmenteiis the sash in the horizontal direction perpendicular to the surface of the sash with a vertically extending outer edge of the side post.

Preferably, the outer edge of the Rahmeπteils άes front slide with the outer edge of the side post aligned over the entire length of the frame part. The alignment of these two edges ensures over the entire height of the sash the Sichersteliung the splash and splinter protection.

The outer edge of the center of the east can be provided on a bearing-shaped inflow face of the side pillar.

Further, the side post may be formed as a frame profile with a first chamber and a second chamber, wherein the second chamber has at least one air outlet opening. Between the first chamber and the second chamber, an air flow through the chambers throttling element can be arranged. By means of the element which throttles the air flow, a pressure is built up in the frame profile upstream of the valve element, whereby the pressure distribution at the air outlet opening along the frame profile is reduced. This ensures a uniform discharge of the support or supply air through the air outlet openings, which in turn ensures a uniform volume flow distribution in the entire fume hood, but especially in the area of the wall surfaces in the fume hood. provides space. The first chamber forms a kind of antechamber, in which a Druckpoister formed, which ensures a uniform pressure distribution in the second Ausblaskammer and thus for a uniform Ausblasung »In addition, increases by the Drosseleiement the residence time of the supply air in the cavity of the Rahmenprofiis.

Preferably, the fume hood is equipped with a Stützstrahltechnik device at a front edge in the region of a worktop and a Stützstrahltechnik device in the side post. Due to the gap provided between the sash and the side post, the support air emerging from the side post profile can enter the withdrawal interior even with the sash closed or the horizontal window open, which has an advantageous effect on the energy efficiency of the fume hood.

A preferred embodiment of the invention will now be described with reference to the accompanying drawings. In the figures show;

Fig. 1 is a front perspective view of a equipped with Stützstrahltechnik fume hood;

2 shows a cross section through the fume hood shown in FIG. 1, in which the effect of the invention is indicated by flow arrows when the sash is partially open;

Fig. 3 shows views of a frame profile intended for use as a side post of a fume hood with a support technique; and

4 shows a cross-sectional view of the frame profi shown in FIG. 3 along the line D-D and of a sash, FIG.

The fume hood 100 shown in a perspective view in FIG. 1 has a withdrawal interior, which is provided at the rear by a baffle 40, laterally by side walls 36, at the front by a closable sash 30 and at the ceiling by a cover 48 is limited. The sash 30 is designed in several parts such that a plurality of vertically displaceable window elements when opening and closing the sash 30 extend in the same direction telescopically one behind the other. The in the closed position of the sash 30 at the bottom arranged window element has at its front edge a Tragflächenprofi! 32 on. In addition, the sash 30 has horizontally displaceable window elements which, even in the closed position of the front bumper 30, allow the laboratory personnel access to the withdrawal interior.

At this point, it should also be noted that the sash 30 may also be formed as a two-part sliding window, the two parts can be moved in opposite directions in the vertical direction. In this case, the opposing parts are coupled via ropes or belts and pulleys with the mass of the sash balancing weights,

Between the Praliwand 40 and the rear wall 62 (Rg, 2) of the trigger housing 60 is a channel to a Abluftsammelka- na! 50 leads on the top of the fume hood. The exhaust collection box! 50 is connected to a building side installed exhaust device.

Below the Arbeitsspiatte 34 of the deduction interior furniture 38 is arranged, which serves as a storage space for different laboratory utensils.

The side posts of the fume hood are provided with airfoil profiles 10 on the upstream side. Likewise, the leading edge, which lies in the region of the working slats 34 or is a part thereof, is provided with an airfoil profile 20 on its inflow side. The wing-like Profϊlgeometrie ensures a low-turbulence or turbulence-free inflow of ambient air into the vent interior with partially or fully open sash. Indicates the sash in An area of the wing profit on an air gap, the effect of low-turbulence or turbulence-free inflow of room air in the deduction interior is achieved even when the sash is closed.

The fume hood 100 shown in FIG. 1 can be seen purely by way of example, since the invention can be applied to different types of fume cupboards, for example table fume hoods, low-ceilinged table fume hoods, drawdowns or walk-in fume hoods. Likewise, these deductions fulfill the European standard DIN EN 14175 valid on the filing date. Furthermore, the deductions can also fulfill other standards, for example the ASHRAE 110/1995, which is valid for the USA,

FIG. 2 greatly simplifies the flow pattern of the inflowing room air 300, the support air 200, 400 and the exhaust air inside the extraction interior and in the channel between the baffle 40 and the rear wall 62 for the exhaust collection channel 50.

The baffle 40 is spaced on the bottom side of the work surface 34 of the discharge interior and of the rear wall 62 of the housing, whereby a Abiuftkanal is formed. In addition, the baffle 40 has a multiplicity of elongated openings 42, 44, through which exhaust air can be sucked out of the withdrawal interior. On the ceiling 48 in the drawing room interior further openings 47, 49 are provided, through which in particular light gases and vapors to the exhaust air collecting channel 50 can be performed. Although not shown in Figs. 1 and 2, the baffle 40 may be spaced from the side walls 36 of the trigger housing. By means of a ventilation gap formed in this way, exhaust air can additionally be introduced through the plaster wall into the exhaust air duct.

As shown in FIG. 2, even with the sash partially open, room air 300 can flow into the draw-off interior even above the lower edge of the sash 30 formed as the airfoil profile 32. This is determined by the Slider 30 and side posts 10 formed gap 70, the geometry of which is described with reference to FIG. 4 in detail.

At Praer Praüwand 40 are a variety of tripod holders 46 can be seen in the rods can be releasably clamped, which serve as brackets for experimental setups in Abzuginneπraum.

FIG. 3 shows views of a side frame frame profile 10, in the left-hand side view in a side view and in the middle illustration in a perspective view. The circled area in the middle figure is shown in an enlarged view in the right figure.

In addition to the guidance of the sliding in the vertical direction sash and a stop 16, which defines the fully open position of the sash, the frame profile 10, which forms the sash 30 facing portion of the sidelight, in the bottom-side Endabschnϊtt an opening 19, by the supply air is injected under pressure into the frame section 10. This opening 19 leads to a over the entire length of the frame profile extending first chamber 12 (FIG. 4), which is fluidly connected to a second chamber 13. The second chamber 13 also extends over the entire length of the frame profile 10 and has a plurality of slot-shaped outlet openings 14, through which the incoming air is blown out in the form of support jets 400.

It should be noted at this point that such frame profiles 10 are provided on both sides of the sash 30, and that the shape of the outlet openings does not have to be slot-shaped, but may also be round, oval or polygonal. It is also conceivable that only one outlet opening is provided, which has the shape of a continuous slot.

With reference to FIG. 4, an air passage or gap 70 between the sash 30 and the frame profile 10 is provided. - ii -

This is a part of the siphon of the fume hood housing 60. More specifically, the air passage is between the illustrated in Fig. 4 left, oblique outer edge of the sash and the sash facing portion of the frame profile 10 in which the guide (lower recess) is provided for the sash 30. The geometry of the air passage 70 is selected so as to prevent passage of particles or liquid from the discharge interior in a direction substantially perpendicular to the surface located in Fig. 4 on the upper side of the frame member 31 of the sash 30. For this purpose, the extending in the vertical direction outer edge 3ia is arranged in alignment with the extending in the vertical direction outer edge 15a of the frame profile 10.

In the example shown in FIG. 4, the air passage 70 is nozzle-shaped or funnel-shaped, with its width increasing from the take-off interior to the take-off outer space (from top to bottom in FIG. 4).

This geometry of the air passage 70 makes it possible to reduce wall friction effects in the drawing room by closing the sash 30 and open horizontal window - the horizontal sliding windows are indicated in FIG. 1 by individual window elements - the support jet emerging from the outlet opening 14 of the frame profile 10 (in FIG. 4 with Hiife indicated by a solid arrow) moves in the form of a Wandstrahis deduction interior backwards and transported pollutants to the rear and from the deduction interior, the nozzle-shaped Nachströmöffnung 70 between the frame member 31 of the sash 30 and the Rahmenprofi! 10 of the trigger post also ensures adequate splash and splinter protection. The advantageous effect of the nozzle-shaped air passage 70 is not only evident in laboratory fume hoods equipped with supporting jet technology. Even without blowing out of Stützstrahien by the Rahmenprofii 10 room air (in Fig. 4 indicated by a dashed arrow) due to the suction effect of the exhaust air through the air passage 70 in the deduction interior and along the walls in the drawing room to rubbing along the wall. As a result, even with a fume hood without Stützstrahltechπik the minimum exhaust air volume flow while maintaining the normalized breakout security is reduced, which in turn has an advantageous effect on the energy efficiency of the fume hood.

In addition, there is still another, the safety of the fume hood effect effect, Since the sash is not sealed hermetically sealed or airtight, room air flows with the sash closed due to the suction effect of the exhaust air in the drawing room at high speed through the top and bottom of the sash This residual air flowing in with the sash closed at high speed affects the Volumenstramverteüung in deduction interior. This creates vortices that lead to a total of non-directional flow and to a longer residence time of pollutants released in the exhaust interior. In the case of smoke or haze, this may result in restricted visibility of the withdrawal interior by the laboratory personnel. In addition, pollutants may be present in the front area of the withdrawal interior, i. accumulate directly behind the sash in increased concentration with the risk that the pollutants can escape during the subsequent opening of the sash of the deduction interior.

The air gap 70 provided between the side post and the sash increases the safety of the trigger by the fact that the inflow flow on the sash 30, if the sash 30 is also provided in the area of the airfoil 32 with a longitudinal slit extending over the width of the sash 30 (not shown), and if not especially in the area of the slaughter walls 36 of the discharge interior, this is compensated As a result, the formation of undirected and / or turbulent flow in the drawing-off interior is prevented when the sash 30 is closed. The risk of outbreak of pollutants with subsequent opening of the front slide 30 is thus lowered drastically,

Since the support jet effect is achieved by the air passage or air gap 70 without support beams, for example, with closed sash 30, the air supply for the support beams 200, 400 are turned off, resulting in a further power savings. In addition, the noise level of the fume hood is lowered by switching off the fans, which convey the air to the support jet outlet openings 14.

As can also be seen in the cross-sectional view of FIG. 4, the support beam indicated by the solid arrow moves along a direction away from the frame 10, giving a sharp angle! to the inner surface of the frame profile .10, and thus occupies the Wandfiäche 36 of the deduction interior. This direction corresponds approximately to the tangent on the supporting profile-shaped inflow surface 15 (for the ambient air) at the front inside of the frame profile 10. The support jet can also be blown out of the frame profile 10 along this direction or parallel to the side walls of the working space.

Between the first chamber 12 and the second chamber 13 of the frame profile 10 is an air flow throttling element Ii, for example, a throttle plate or a permeable membrane. Through the throttle element 11 is in the first chamber 12 a Generates pressure sufficient to allow a uniform Luftaustrϊtt from all the air outlet openings 14 which are arranged in the vertical direction along the frame profile 10. The uniform air outlet ensures a uniform volume flow distribution along the wall surfaces 36 of the discharge interior, which in turn has an advantageous effect on the energy efficiency, ie the Mestndestabluftvotumenstrorn. The throttle element 11 may extend over the entire length of the frame profile 10, but at least over that length over which the air outlet openings 14 are arranged distributed.

The frame profile is in the cross-sectional view of Fig. 4 as a one-piece Profϊltei! 10 trained. The arranged on the inside, semicircular bulges 17 serve as a guide for the sash 30. The side of the first chamber 12 located inside portion 18 is used for attachment to the housing of the fume hood, For fastening the throttle element 11 between the first and the second chamber 12th , 13 serve two each directed towards the inside of the frame profile, raised trained webs, in each of which a groove is provided with a width corresponding to the thickness of the throttle element 11, the Drosseielement 11 can thus be pushed during assembly in the end frame 10 in the frame.

The Drosseielement 11 may have openings whose spacing and / or size vary along the frame profile 10. In particular, the distance and / or the size of the openings in the throttling element 11 may increase or decrease with increasing distance from the working plate 34 in order to ensure a uniform discharge of the support jets 400 via all outlet openings 14. In other words, since the supply point of the supply air in the exemplary embodiment of the frame profile 10 shown here is at the lower end, ie in the region of the work surface 34, the arrangement and size of the openings in the throttle element or aimed at changing the Drosselquerscbnitts the pressure distribution between the two chambers 12, 13 and the Geschwindigkeitsverteϊlung the blown out support air 400 along the frame profile 10 changed.

If the supply point of the supply air lies in the upper region of the frame professional 10, the Drosseiquerschnitt of the throttle element 11 entSang the Rahmenprofiis 10 can be reversed accordingly. Likewise, the throttle cross-section of the drain element 21 in the frame profile 20 can be adjusted in the desired manner.

By targeted Wahi the throttle cross section of the arranged within the frame profile 10 throttle element 11 is advantageously influenced the volume flow distribution in the drawing interior, in particular on the wall surfaces 36 and the bottom surface 34. To optimize this volume flow distribution, the suction openings or suction openings 42, 44, 47, 49 provided on the baffle 40 and on the ceiling 48 in the drawing-off interior can be adapted accordingly. For this reason, the wall-side slits 42 provided in the baffle 40 in the region of the worktop are designed to be longer than the slits 44 (see FIG. 1) provided in the center of the baffle 40, due to the increased influx of supporting air 200, 400 in the region of the worktop 34 and in the region of the wall surfaces 36 of the deduction interior 42 more exhaust air and thus pollutants is removed by the enlarged slots. This has an advantageous effect in particular on the removal of heavy gases within the withdrawal interior.

Accordingly, the suction openings 47 provided in the rear area of the ceiling 48 can be made larger than the openings 49 facing the sash 30.

Claims

claims

1. fume hood (100), comprising a with a laboratory housing (60) movably connected sash (30) for opening and closing a deduction interior, in which between the sash (30) and a Seitenpfosteπ (10) of Laborgehäυses (60) an air passage ( 70) is provided, which is designed to generate wall beams in the deduction interior.

2. fume hood (100) according to claim 1, wherein the air passage (70) is nozzle-shaped.

3. fume hood (100) according to claim 1 or 2, wherein the air passage (70) from the withdrawal interior to the AbΣugauraum in the horizontal direction becomes wider.

4. fume hood (100) according to any one of the preceding claims, wherein the geometry of the air passage (70) is such that a hypothetical, substantially rectilinear perpendicular to the surface of the sash (30) extending particle or liquid flow is not from the exhaust interior in äen exhaust external space can pass through.

5. fume hood (100) according to any one of the preceding claims, wherein a vertically extending, the deduction interior facing outer edge (31 a) Rahmenteiis (31) of the sash (30) in the horizontal direction perpendicular to the surface of the sash (30) with a vertically extending Outer edge (15 a) of the side post (10) is aligned.

6. fume hood (100) according to claim 5, wherein the outer edge (31 a) with the outer edge (15 a) over the entire length of the Rahmeπ- part (31) is aligned.

7. fume hood (100) according to claim 5 or 6, wherein the Au f3enkante (15 a) on a wing-shaped inflow surface (15) of the side post (10) is provided.

8. fume hood (100) according to any one of the preceding claims, wherein the Seitenπpfosten (10) as a frame profile with a first chamber (12) and a second chamber (13) is formed, wherein the second chamber (13) at least one air outlet opening (14 ), and in which between the first chamber (12) and the second chamber (13) a Luftdurchfiuss through the chambers (12, 13) throttling element (11) is arranged,

9. fume hood (100) according to any one of the preceding claims, which is equipped with a Stützstrahltechnikseinrichtung (20) at a front edge in the region of a Arbeitsspiatte (34) and a Stützstrahltechnikeinrichtung (10) in the side post.