Vortex baffle for a ventilated enclosure

Abstract

A ventilated enclosure includes a vortex baffle to harness the turbulence of air in a way that uses less exhaust air while still providing ample protection to the user. The vortex ventilation system uses the total interior shape and proportion of the ventilated enclosure to direct the motion of air flow in a manner that improves efficiency. The vortex ventilation baffle can enhance the way air naturally curls, or rolls, as air flows through the enclosure. The vortex baffle can cause a mono-stable vortex to from in the enclosure. This vortex is resilient to disturbances that cause ventilated enclosures, such as chemical fume hoods, to spill. The stable vortex is above the work surface and less affected by the way apparatus is loaded inside the enclosure. The vortex baffle achieves better containment (improved safety) at lower exhaust flow (improved energy consumption) as compared to conventional ventilated enclosures.

Claims

1. A ventilated enclosure comprising: a vortex baffle mounted inside the ventilated enclosure that is a continuous, unbroken, vaulted structure that is symmetrical as viewed in profile, wherein front and rear edges of the vortex baffle form parallel lines that define a horizontal plane that is parallel to the plane of a work surface of the ventilated enclosure and perpendicular and tangential to a plane of an open face that is the sole means of communicating fluid from an outside to an interior of the ventilated enclosure; and a single exhaust slot disposed between the symmetrical vaulted interior vortex baffle and a rear housing of the ventilated enclosure, the single exhaust slot providing a sole fluid communication between the interior of the ventilated enclosure and an exhaust duct, wherein an interior height of the vortex baffle above the work surface of ventilated enclosure is equal to about 1.6 times a working depth of the ventilated enclosure; the working depth of the ventilated enclosure is equal to a distance from the work surface to a lower edge of the vortex baffle at the single exhaust slot; and a height of an opening, extending vertically from the front edge of the vortex baffle, of the ventilated enclosure is equal to or less than the working depth of the ventilated enclosure wherein the opening provides the only flow of air into the ventilated enclosure during use thereof.

2. The ventilated enclosure of claim 1, wherein the symmetrical vaulted interior vortex baffle is an arc-shaped baffle.

3. The ventilated enclosure of claim 1, wherein the symmetrical vaulted interior vortex baffle is an angled baffle.

4. The ventilated enclosure of claim 3, wherein the angled baffle includes vertical components along a front and a rear of the angled baffle, slanted components extending from tops of the vertical components at a first angle, and a horizontal component interconnecting ends of the slanted components at a second angle.

5. The ventilated enclosure of claim 4, wherein the first angle and the second angle are each about 45 degrees.

6. The ventilated enclosure of claim 1, wherein the symmetrical vaulted interior vortex baffle is an angled baffle comprised of at least five flat panels that are approximately the same size.

7. A ventilated enclosure comprising: a continuous, unbroken and symmetrical semi-circular vaulted interior vortex baffle mounted inside the ventilated enclosure, wherein the vortex baffle is symmetrical as viewed in profile; and a single exhaust slot disposed between a rear edge of the symmetrical vaulted interior vortex baffle and a rear housing of the ventilated enclosure, wherein: the single exhaust slot provides a sole fluid communication between an interior of the ventilated enclosure and an exhaust duct; an interior height of the vortex baffle above a work surface of the ventilated enclosure is equal to about 1.6 times a working depth of the ventilated enclosure; the working depth of the ventilated enclosure is equal to a distance from a work surface to a lower edge of the vortex baffle at the single exhaust slot; and a height of an opening extending vertically from a front edge of the vortex baffle of the ventilated enclosure is equal to or less than the working depth of the ventilated enclosure, wherein the front edge of the vortex baffle is a top edge of an open face of the ventilated enclosure that provides the only flow of air into the ventilated enclosure during use thereof.

8. A ventilated enclosure comprising: a continuous, unbroken and symmetrical vaulted interior vortex baffle mounted inside the ventilated enclosure, wherein the vortex baffle is symmetrical when viewed in profile; a single exhaust slot disposed between a rear edge of the symmetrical vaulted interior vortex baffle and a rear housing of the ventilated enclosure; and a single opening permitting air to enter the ventilated enclosure, wherein a working depth of the ventilated enclosure, a ratio of an interior height of the ventilated enclosure to the working depth, and an opening height are chosen to provide a stable vortex in the ventilated enclosure when air is drawn out through the single exhaust slot, and wherein the symmetrical vaulted interior vortex baffle is an angled baffle comprised of at least five flat panels that are approximately the same size.

9. The ventilated enclosure of claim 8, wherein the first angle and the second angle are each about 45 degrees.

10. The ventilated enclosure of claim 8, wherein the interior height of the vortex baffle above the work surface of the ventilated enclosure is equal to about 1.6 times the working depth of the ventilated enclosure.

11. The ventilated enclosure of claim 8, wherein the opening height of the ventilated enclosure is equal to or less than the working depth of the ventilated enclosure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic cross-sectional view of a ventilated enclosure according to an exemplary embodiment of the present invention; and

(2) FIG. 2 is a schematic cross-sectional view of a ventilated enclosure according to another exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(3) The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.

(4) Broadly, an embodiment of the present invention provides a ventilated enclosure that includes a vortex baffle to harness the turbulence of air in a way that uses less exhaust air while still providing ample protection to the user. The vortex ventilation system uses the total interior shape and proportion of the ventilated enclosure to direct the motion of air flow in a manner that improves efficiency. The vortex ventilation baffle can enhance the way air naturally curls, or rolls, as air flows through the enclosure. The vortex baffle can cause a mono-stable vortex to from in the enclosure. This vortex is resilient to disturbances that cause ventilated enclosures, such as chemical fume hoods, to spill. The stable vortex is above the work surface and less affected by the way apparatus is loaded inside the enclosure. The vortex baffle achieves better containment (improved safety) at lower exhaust flow (improved energy consumption) as compared to conventional ventilated enclosures.

(5) Referring now to FIGS. 1 and 2, a fume hood 10, 28 can include a vortex ventilation baffle 24, 29 disposed as a rigid structure at a top region of the fume hood 10. The ventilation baffle 24 may have an arc shape 26. The ventilation baffle 29 may have a vaulted shape defined vertical components 34 interconnecting with a horizontal component 30 via sloped components 32, as described in greater detail below. The ventilation baffles 24, 29 includes a single exhaust slot 18 in the upper rear of the hood.

(6) Air flow 14 can enter the fume hood 10, 28 through an intake opening O. The height of the intake opening O may be controlled by a sash or may be fixed, depending on the configuration of the ventilation enclosure. The air flow that is not immediately exhausted through the slot, encounters a symmetrical vaulted interior ceiling (such as vortex ventilation baffle 24, 29). Air flows around the vaulted space at the top and rolls down the top interior front of the hood to meet air entering from outside of the hood. This mixing of air from inside and outside the hood induces and enhances the stable vortex that forms in the upper portion of the hood. The motion of the stable vortex can keep air moving through the open face and away from a person using the hood. The vortex effect improves the containment (and, thus, safety) of fumes inside the hood while using a relatively low exhaust air flow.

(7) The exhaust air flow can be taken out through the sole exhaust slot 18, through an exhaust duct 20 to be expelled as exhaust 22. As exhaust 22 is removed, new air flow 14 enters, sustaining the vortex.

(8) The vaulted ventilated top (also referred to as the vortex ventilation baffle 24) can have an arc shape 26, typically a semi-circular arc shape, as shown in FIG. 1. In some embodiments, the vortex ventilation baffle 29 can be formed from flat surfaces with corners angled at 45 degrees. The vortex ventilation baffle 29 is designed as a symmetrical vaulted interior ceiling having the vertical components 34 at the front and back, with slanted components 32 extending from a top edge of the vertical components 34. The slanted components 32 connect with the horizontal component 30. In the dimension shown in FIG. 2, baffle components 30, 32 and 34 should be the same length. Other designs are contemplated within the scope of the present invention, provided that they provide a symmetrical vaulted interior ceiling with a single exhaust slot 18 formed where the rearward vertical component 34 is adjacent to the housing 12 of the hood 28.

(9) In an exemplary embodiment of the present invention, the total interior height H of the enclosure can be configured to be about 1.6 times the working depth D of the enclosure. The single exhaust slot 18 can be located a distance S above a work surface 16. The distance S can be equal to the working depth D of the enclosure. The height of the intake opening O can be equal to or less than the working depth D of the hood.

(10) The vortex ventilation baffle 24, 29 can be made using conventional techniques and can be fabricated from various sheet materials, such as metal, glass, fiberglass, plastic (Lexan, for example), composite resin or the like.

(11) While the above description focuses on chemical fume hoods, the design aspects of the present invention can be applied to various ventilated enclosures in various industries and disciplines.

(12) It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.