US20100159820A1

US20100159820A1 - Diffuser assembly for non-turbulent air flow

Info

Publication number: US20100159820A1
Application number: US12/317,270
Authority: US
Inventors: H. Henry Hirsch
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-12-22
Filing date: 2008-12-22
Publication date: 2010-06-24

Abstract

The invention is an air flow diffuser that produces an even and non-turbulent flow of air from ventilation or A/C. The diffuser combines a pressure chamber and a discharge chamber to produce a non-turbulent even flow of air perpendicular to the face of the discharge chamber. The pressure and discharge chambers are contiguous with the ducted air flowing first into the pressure chamber and then into the discharge chamber from which chamber the non-turbulent, evenly flowing air flows into the space. Though the diffuser is developed for a downward air flow, the diffuser can be constructed in several shapes, such as triangular, allowing air flow in any direction that is perpendicular to the plane of the discharge plate.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT

Not Applicable

REFERENCE TO SEQUENCE LISTINGS

Not Applicable

BACKGROUND OF THE INVENTION

This invention is in the field of endeavor dealing with ventilation with specific air distribution.
Current air supply diffusers are designed with deflectors or louvers for directional flow so as to direct air flow to specific areas of a space without regard to turbulence and contained air flow. This directed air flow is acceptable for basic heating, cooling, ventilating and/or other similar applications within an enclosed space. However, drafts and other turbulent conditions may be created which may prove to be “unacceptable” for applications in certain environments. Therefore a more controlled and non-turbulent air flow is required for providing a more comfortable or even distribution of air.

BRIEF SUMMARY OF THE INVENTION

The invention resolves the issue of turbulence and dispersion of delivered air. It causes the flow of supplied air to be smooth, evenly distributed, and perpendicular to the face of the diffuser. A specific problem the invention solves is the cross ventilation that occurs when louvered or deflector controlled air flow bounces off walls, beams and other surfaces. For example, this air movement particularly affects an open flame or heated cooking surface where the fumes should rise vertically by convection from the heated area into an exhaust hood directly above the heated surface. Any cross ventilation diverts the smoke, fumes and heat producing convection currents, even with an exhaust fan in the hood, such that the capture of these products by the exhaust hood is disturbed, preventing the exhaust hood from capturing all the elements.
Simply increasing the air flow in the exhaust hood causes increased air turbulence in the space around the exhaust hood and does not significantly increase the amount of emissions collected by the exhaust hood. In addition, increasing the flow in the exhaust hood, requires additional make-up air and a subsequent increase in A/C and/or ventilation capacity, but still does not solve the problem of smoke, heat and fumes migrating into the space around the exhaust hood. Providing a non-turbulent air flow, in proximity of the exhaust hood, eliminates the cross ventilation issues caused by current make-up air supply diffusers.
The invention regulates and directs air flow by pushing air into the space by pressure as opposed to deflecting the space make-up air from the ventilation or A/C supply air source. To accomplish this, a pressure chamber is created in the top of the diffuser for non-turbulent air flow. This pressure chamber allows ventilation or A/C air from the duct to enter the chamber which is compressed with a pressure plate. The pressure plate is installed into the body of the diffuser, has a plurality of perforations and is mounted to the diffuser with a plurality of screws so as to create a pressure chamber larger than the discharge chamber. The pressure chamber forces air into the discharge chamber which is formed by attaching a plate to the bottom of the diffuser with a plurality of perforations, which are larger than those perforations in the pressure plate.
Turbulence is eliminated since the air delivered into the space is not being propelled by a fan nor caused to bounce off deflectors or louvers. The direction is perpendicular to the discharge plate of the diffuser since the air is evenly “pressed” into the space across the entire face of the discharge plate.
The diffuser may be a variety of shapes and sizes depending on the available apace in the ceiling and the needed proximity of the diffuser providing make-up air to the hood requiring the make-up air. Examples of shapes are rectangular, triangular, quarter circular and full cylindrical. Air flow may be vertical or horizontal and the sheet metal of exposed diffusers may be covered to fit the space decor.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE INVENTION

FIG. 1( a) Plan view of the diffuser

FIG. 1( b) Elevation view of the diffuser

FIG. 1( c) Internal view of diffuser at section A-A

FIG. 2( a) Isometric view of rectangular diffuser

FIG. 2( b) Isometric internal view at section A-A of rectangular diffuser

FIG. 3( a) Isometric view of triangular shaped diffuser with vertical air discharge

FIG. 3( b) Isometric internal view at section B-B of triangular diffuser with vertical air discharge

FIG. 4( a) Isometric view of triangular shaped diffuser with horizontal air discharge

FIG. 4( b) Isometric internal view of triangular diffuser with horizontal air discharge at section C-C

DETAILED DESCRIPTION OF THE INVENTION

The diffuser assembly for non-turbulent air flow replaces currently used diffusers in applications where turbulence and uncontrolled dispersion of the air from a ventilation or A/C unit do not meet the requirements of the system. Representative examples include: the use of ventilation or A/C as make-up air for grease exhaust hoods for cooking over open flame or heated grill surfaces; ventilation or A/C make-up air for exhaust hoods in laboratories where the hoods are used to exhaust toxic or noxious fumes; for the ventilation or A/C provided make-up air for spray booths where the over-spray is filtered and exhausted outside the facility; and in meeting rooms, restaurants and auditoriums where less turbulence reduces unwanted drafts and air currents. With the make-up air being provided with current diffusers that employ louvers or deflector plates to direct air flow there is still turbulence that causes unwanted fumes from the heated grill or open flame cooking surfaces, or laboratory tables, or spray booths to migrate into the space outside of the exhaust hood.
Other inventions such as U.S. Pat. No. 5,733,191 (Lam), and, U.S. Pat. No. 4,726,285 (Kelly), disperse air into the space in the general direction described in the patent. Lam uses movable deflection plates in the diffuser to direct the air flow, and Kelly uses dimples to disperse the air laterally. Nothing in either of these inventions or other similar inventions, however, corrects the turbulence created by velocity pressure normal to air propelled by a fan only, nor do they achieve a contained and directed flow of air. In their patent application 20080176506 by Gebke, et al, dated Jul. 24 2008, a different technology is employed to achieve the desired non turbulent flow which involves porous fabric material in lieu of pressure or discharge plates as used in the invention. Use of porous fabric material as opposed to rigid plates present the problems of determining the needed porosity and accounting for dust buildup on the material from air from the ventilation or A/C system duct that could affect the air flow.
To achieve the desired turbulent free, controlled and directed air flow, velocity pressure, which exists in all air ducts, must be converted to static pressure which is then used to move the air from the ventilation or the A/C to the desired space. This conversion is accomplished by directing the ducted air under velocity pressure into a pressure chamber that then presses air into a discharge chamber, and finally into the space. The diffuser with the chambers as described is shown in FIG. 2( b). The resultant air being exited into the space is turbulent free and mono-directional, orthogonal to the plane of the exhaust chamber plate.
The diffuser is a rectangular box constructed of sheet metal with the corners and sides welded, riveted or otherwise attached to each other to form a compartment that will not leak air under pressure. The length and width of the box are determined by the desired size of the diffuser face and the required air volume. The height, length and width of he box are dimensioned such that there is sufficient volume and shape to allow for the two required chambers: pressure and discharge. The top of the box is enclosed except for a hole to allow the introduction of air from the ventilation and/or A/C duct to which the diffuser will be attached. The pressure chamber is formed by attaching a pressure plate that is the same dimensions as the length and width of the box and perforated with a plurality of holes such that the pressure chamber is larger than the lower, discharge chamber. The attachment of the pressure plate to the box may be by a plurality of screws or by rivets or any other means of attachment such that the pressure plate is parallel to the bottom of the box. The discharge chamber is directly below and contiguous to the pressure chamber. The chamber is formed by installing a discharge plate that is the same dimensions as the length and width of the box and perforated with a plurality of holes which are larger than the holes in the pressure plate, on the bottom of the box. Installation may be by brackets and a plurality of screws, rivets or by any other means such that the discharge plate is parallel to the pressure plate and flat with respect to the sides of the box. The construction of the rectangular diffuser is shown in FIGS. 1( a), 1(b) and 1(c).
The basic rectangular diffuser is designed to be ceiling mounted and for the discharge air to move straight down. The length and width dimensions of the box are therefore partially determined by the type of ceiling and the location of ceiling supports. Appropriate mounting hardware including frames, brackets, support wires or other building code requirements can be adapted to the diffuser in the same manner as the mounting hardware is adapted to current air diffusers.
Other configurations of the box are possible including but not limited to: triangular or quarter circular for mounting in corners or between the vertical wall and the ceiling, fully cylindrical for mounting around support columns and below the ceiling allowing the air flow to be horizontal. FIGS. 3( a) and 3(b) show a triangular diffuser with air flow from the bottom for a vertical air flow. FIGS. 4( a) and 4(b) show the triangular diffuser with horizontal air flow. Both of these configurations allows the diffuser to be mounted in the corner of two adjacent walls or below the ceiling abutting the ceiling and the wall.
The construction of the alternative shapes employs the same principle of having a pressure chamber and perforated pressure plate, and a contiguous discharge chamber and perforated discharge plate, where the pressure chamber receives the ducted air from the ventilation or A/C supply air. Where the alternative configurations are mounted in visible areas and in the space, decorative coverings can be installed on the showing sheet metal planes of the diffuser to blend with the space decor.

Claims

1. An air diffuser for non-turbulent air flow comprising: a rectangular sheet metal box, the corners and seams of which are constructed to prevent air leakage under pressure; with the top of the box solid except for a hole to allow for connection to a ducted air supply; with the body of the box divided into contiguous chambers; with the upper or pressure chamber created by attaching a metal pressure plate containing a plurality of perforations parallel to the top of the box greater than half of the height dimension of the box and having dimensions equal to the length and width of the box; with the lower or discharge chamber created by attaching a metal discharge plate containing a plurality of perforations flush with the bottom of the box with the same dimensions as the length and width of the box; with the bottom plate perforations larger than the perforations in the center plate; and with the diffuser assembly including all necessary brackets and mounting parts to enable installation in the ceiling of a building.

2. The diffuser for non-turbulent air flow of claim 1, wherein the length of the box is twice the width.

3. The diffuser for non turbulent air flow of claim 1, wherein the body of the box contains an inside sound and insulation lining.

4. The diffuser for non-turbulent air flow of claim 1, wherein the pressure plate containing a plurality of perforations is attached to the inside of the box with a plurality of screws or rivets to brackets in the box.

5. The diffuser for non-turbulent air flow of claim 1, wherein the pressure plate containing a plurality of perforations is attached to the inside of the box by welding the plate to the sides if the box.

6. The diffuser for non-turbulent air flow of claim 1, wherein the discharge plate containing a plurality of perforations which are larger than the perforations of the center plate is attached to the bottom of the box with a plurality of screws or rivets.

7. The diffuser for non-turbulent air flow of claim 1, wherein the box is triangular such that it will fit in the corner and against the walls of a room or space and at ceiling height.

8. The diffuser for non-turbulent air flow of claim 7, wherein the plate with a plurality of perforations connected to the discharge chamber is the vertical hypotenuse side of the triangular chamber and the bottom of the box is solid, creating air flow parallel to the ceiling.

1. An air diffuser for non-turbulent air flow comprising a pressure chamber connected to receive air from an air source, one wall of said pressure chamber containing a plurality of perforations, a discharge chamber mounted to receive air from said pressure chamber through said perforated wall and having a discharge chamber wall formed with a plurality of perforations larger than those of the pressure chamber

2. The air diffuser of claim 1 wherein: said discharge wall is parallel to the perforated wall of said pressure chamber

3. The air diffuser of claim 1 wherein: said air diffuser is a hollow box having one surface formed with a means for connecting to an air source.

4. The air diffuser of claim 1 wherein: said discharge chamber is contiguous with said pressure chamber.

5. The air diffuser of claim 3 wherein: said one surface is the top of said diffuser.

6. The air diffuser of claim 3 wherein: said one surface is a side wall of said air diffuser.

7. The air diffuser of claim 3 wherein: said perforated wall is parallel to said means.

8. The air diffuser of claim 3 wherein: said perforated wall is perpendicular to said means.

9. The air diffuser of claim 1 wherein: said air diffuser is rectangular.

10. The air diffuser of claim 1 wherein: said air diffuser is triangular

11. The air diffuser of claim 1 wherein: said discharge chamber has greater volume than said pressure chamber.

12. The air diffuser of claim 1 wherein: the length and width of said pressure chamber and said discharge chamber are not equal.

13. The air diffuser of claim 1 wherein: the length and width of said pressure chamber and said discharge chamber are equal.

14. The air diffuser of claim 1 wherein: one wall of said pressure chamber, other than said perforated wall, contains a hole for connection to an air source.

15. The air diffuser of claim 10 wherein: the perforated wall of said pressure chamber is internal t said triangular diffuser and parallel to said perforate wall of said discharge chamber.

16. The air diffuser of claim 10 wherein: one wall of said pressure chamber, other than said perforated wall, has a hole to allow air to enter from an air source.

17. The air diffuser of claim 1 wherein: the two chambers are of different shapes.

18. The air diffuser of claim 1 wherein: the perforated wall of said pressure chamber and the perforated wall of said discharge chamber are parallel.