AU665045B2 - Air flow regulator - Google Patents

Description

0 Patents Act 1990 0RI GINAL COMPLETE SPECIFICATION STANDARD PATENT t the best method of performing it known to me:- This invention relates to an air-flow regulator, that is to say a valve for use in regulating or controlling the flow of air, and it refers particularly to an air regulator for incorporation in, or for use in, air *1 cooling, air heating and/or air conditioning apparatus and/or installations. The invention may be used for other purposes.

It is an object of the invention to provide an air-flow regulator which will provide a substantially laminar flow of air over and past the regulator, a substantially straight-line or linear relationship between S the air flow through the regulator and the degree of opening of the regulator, a low pressure drop as between the air inlet opening and the air outlet opening, and a very low air noise factor in the operation of the regulator.

A subordinate object is to provide means for measuring the air flow through a variable air volume terminal unit whereby sensor means within the airflow regulator unit may be used to adjust and control the opening of the valve. It is believed that this may be achieved by reason of the relatively low turbulence in the air flow.

'Accuordin ob ehc is etonthi providmea: od an air-ig t rfl fw unit hriug air-flow regulator of somewhat n w M*_ch is capable of being

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1 I 4:1 4- 1, 4- 1,r- T 7" i ;i Ii Rb~E=lt t 1l 1A- According to the present invention in one aspect a fluid-flow regulator of aerofoil form capable of varying the volume rate of flow in a duct wherein it is mounted, includes means for expanding or retracting the regulator to vary the effective cross-section of said duct.

Considering all imaginary planes crossing the duct and the regulator therein, the "effective cross section" is the minimum area between the respective outer and inner contours of the regulator and duct. If for example the regulator were an ellipsoid coaxial with the duct, the effective flow cross section would be 0 measured on a plane normal to the axis and intersecting the ellipsoid's centre.

For the purposes of this specification "aerofoil" means a body which although it can offer a substantial barrier to a flow, is faired or "streamlined" so as to reduce turbulence, but does not necessarily experience "lift" From another aspect the invention provides a variable-volume device for i :15 a valve for use in a rectangular duct of an air-conditioning system or the like and comprising: S(a) first and second valve members each being pivotal around an axis which in use is arranged to extend across a duct; each valve member being convex and of continuous plate-like form 20 when viewed at right angles to the pivot axis; each valve member extending from its pivot axis in a downstream direction along the duct; actuating means provided for displacing the respective valve members towards or away from one another so as to move between open and closed positions of the valve; the actuating means being located in a zone generally between the valve members and comprising a rotatable shaft extending across the valve duct and adapted to be rotated when in use; the shaft carrying a pivotal linkage which is pivotally connected to the respective valve members; the valve members being such that in any open position air flow is guided by the valve members down the duct without interaction with the 15/6 SLP7893SPE.1

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~aara~x /3 3 I?-t!jq -1B actuating means; and each valve member having an elongated surface extending across the valve duct for contacting a wail of the duct when the device is in the closed position.

From a further aspect the invention provides a variable volume device for a valve for use in a rectangular duct of an air-conditioning system or the like and comprising: first and second valve members each being pivotal around an axis which in use is arranged to extend across the duct; each valve member being of continuous convex plate-like form when viewed at right angles to the pivot axis; each valve member extending from its pivot axis in a downstream direction along the duct to a free end portion; t ,:15 actuating means provided for displacing the respective valve members S towards or away from one another so as to move between open and closed positions of the valve; vv(e) the actuating means being located in a zone generally between the valve members and comprising a rotatable shaft extending across the valve duct and adapted to be rotated when in use; i the shaft carrying a pivotal linkage which is pivotally connected to the p respective valve members; ig) the free end portion of each valve member being located downstream t°T of the actuating means, whereby in any open position air flow is guided by the Iro valve members down the duct without interaction with the actuating means; and the free end portion of each valve member having an elongated surface for contacting a wall of the duct in the closed position.

The air flow regulator provided by this -1 15/6f95LP7893.SPE_ UL air.

Preferably, the somewhat aerofoil design of air-f regulator has two nose parts of arcuate shape hingedly connect together at their leading edges and two tail parts hingedly con ted together at their trailing edges, each of the tail parts bein ingedly connected to a nose part so that the four said parts are c ected together and may be expanded outwardly to an extended sition or retracted inwardly to a "collapsed" position.

This somewhat ofoil-shaped valve member is herein referred to as an aerofoil- e valve or air-control valve, it being understood that the term erofoil" does not, in this context, imply that the flow of air over 1~c I 4 a C C C

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C4 l l-L.3 invention may be incorporated in a single duct unit for simple operation, or in a dual or twin duct unit of any one of a number of different designs for different purposes, such-as the mixing of cool and room-temperature or normal air, and it may incorporate a pressure sensing means for use in 20. controlling and adjusting the regulator that is to say, to expanded or retract the valve and/or heating means which may be located at the air outlet end of the apparatus.

In order that the invention may be clearly understood and conveniently put into practical effect we shall now describe with reference to the accomcc 25. panying illustrative drawings, a variable air volume unit incorporating the air regulator means provided by this invention, and having a single duct, and then describe other units incorporating the same air regulator means, as well as several modifications. In these drawings: Fig. 1 is a side elevation of the unit having a single duct; Fig. 2 shows that unit in end elevation; Fig. 3 depicts a plan view of the unit of Fig. 1; Fig. 4 is a longitudinal cross-section taken on the line and in the direction of the arrows 4 4 of Fig. 2, showing the air-regulator valve in a retracted position; Fig. 5 shows another longitudinal cross-section taken on the line and in the direqtion of the arrows 5 5 of Fig. 2; Fig. 6 is a transverse cross-section taken on the line and in the direction of the arrows 6 6 of Fig. 1; ig. 7 is a transverse cross-section taken on the line and in the L4 0Z Z\ direction of the arrows 7 7 of Fig. 1;

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tli~PBPllin 3/3 -3- Fig. 8 shows a side elevation of a dual duct unit incorporating airregulator valves according to the invention; Fig. 9 is an end view of the unit shown in Fig. 8; depicts the unit of Fig. 8 in plan view; Fig.11il shows a side elevation of a twin duct overhead unit incorporating air-regulator valves according to the invention; Fig.12 is an end view of the unit shown in Fig. 11; Fig.13 depicts the unit of Fig. 11 in plan view; Fig.14 shows a side elevation of a twin duct underfloor unit incorporating air regulator valves according to the invention; is an end view of the unit shown in Fig. 14; and Fig.16 depicts the unit of Fig. 14 in plan view.

Figs. 4, 5, 6 and 7 are on a scale somewhat larger than that of the other figures of the drawings.

In the following description reference will be made initially to the unit illustrated in and by Figs. 1 to 7, inclusive.

S The single duct variable air volume unit shown in these figures has an outer casing 21 which, as shown, is rectangular in transverse crosssectional shape, and of suitable length and transverse dimensions. At one end of the casing 21 is an end plate 22 with an inlet opening 23 surrounded by a flange or neck 24 which constitutes the air inlet. The opposite or outlet end of the casing 21 is open. The casing is lined on the inside, for a major part of its length, with acoustic insulation 25, and ther is an -3-i inner metallic lining 26 at the front end of the castig 21, Ai rearwardly from the end plate 22. Said lining 26 is inset from the Sacoustic insulation 25 on two of the opposite sides, as shown in Fig. 6.

Two substantially rigid valve seatings 27 of somewhat arcuate shape, each having a foam lining 28 to provide a resilient seating for the valve, are provided at the inner ends of the metallic lining 26, said seatings 27 i being on opposite sides of the interior of the casing 21 and equally spaced from the end plate 22. The foam lining 28 also extends across the other two inner sides of the casing 21.

An air-flow control valve 29 is mounted rearwardly of said valve seatings 27. Said valve 29 has two arcuately shaped nose parts 30 of complementary shape which are hingedly connected together at their leading edges by a hinge pin or rod 31 located on the centre line of the passageway through the unit and having its opposite ends mounted in the opposite inner side walls of the casing 21, the opposite ends of said nose parts 30 being shaped to fit snugly against the linings 28 on the seatings 27 when moved RA4. to expanded position so as to restrict or shut off the flow of air through iiiv The single duct var i air vl ume uni shown n thes figure has a -4the interior of the casing 21.

Hingedly connected to the trailing edges of the nose parts 30 by hinge pins 32 are two tail parts 33 of substantially flat or straight shape which are hingedly connected together at their trailing edges by a hinge pin 34.

Thus, the four parts 30 and 33 aire hingedly connected together at four locations and may be moved from a retracted position as illustrated in Fig. 4 to a fully expanded or closed position, or to any intermediate partly-closed position, by moving the hinge pin 34 towards the hinge pin 31, or retracted again by moving the hinge pin 34 in the reverse direction.

The opposite ends of the hinge pin 34 are mounted slidably in slots provided in the opposite side walls of the casing 21, so as to hold the control valve or regulator 29 in correctly aligned position within the casing 21.

A control rod or drive shaft 36 extends transversely through one of the side walls of the casing 21 and is mounted for turning movement in the opposite side wall. On the rod 36 are fastened two radius arms 37, each connected by a link or crank 38 to the hinge pin 34, so that turning movement of the control rod 36 will effect linear movement of the hinge pin 34 and thereby effect closing or opening movement of the control valve 30, 33.

When the nose parts 30 are expanded fully so as to bear firmly against the rearward surfaces of the foam-lined seatings 27/28 on opposite inner sides of the casing 21 the flow of air through the unit will be limited to a minimum, and when the hinge pin 34 is moved to the limit of its travel away from the nose parts hinge pin 31 the valve will be fully retracted, and opened, and the permitted air flow through the unit will be the maximum.

Intermediate positions of the valve parts will effect a variation in the permitted air flow through the unit. i The control rod 36 may be connected to a suitable motor (not shown) for effecting slow-motion turning of the rod such as a 24 volt motor so as to operate the air-control valve 29.

*i As stated, the two nose parts 30 are of arcuate shape preferably cylindrical quadrants, though other arcuate shapes (such as elliptical) may be found to be suitable. Similarly, the tail parts 33 are preferably straight but it may be found suitable to have them of curved shape, such as slightly convex. The two nose parts 30 and the two tail parts 33 make up a somewhat aerofoil shaped valve member.

Mounted within the casing 21 is a pressure sensor 40 designed to achieve a logarithmic relationship between pressure developed within the unit and actual delivery of air flow. It is believed the stability of the pressure signal is achieved by virtue of the location of the sensor probe within the chamber or space within the valve 30 33, ensuring asubstantially static environment. It is believed the pressure signal provided by the sensor is related to the resultant back pressure created at the discharge end of the unit, which alters as the air flow alters and, consequently, the pressure signal is altered proportionately, such alteration being picked up by a connected control system (not shown) to command the operation of the motor for effecting operation of the control rod 36. The single duct variable air volume terminal unit depicted in these Figs.! to 7, inclusive is adapted to vary air supply to a space to be air-conditioner from a maximum flow to minimum (virtually, nil) flow in response to the temperature in that space so as to maintain a substanially constant predetermined temperature. The air supplied to the inlet opening 23, through the neck 24, will originate from a central plant provided to deliver air 1S. to a number of such units. It is further believed that the air flow will S have a nearly linear relationship with the valve position. Arrows A and t't' B indicate the direction of air flow.

t If desircd the unit shown in these drawings may be provided with suitable t heating meens, such as electrically-operated reheating elements or water -supplied heating coils, which may be mounted at or close to the outlet end of the casing 21.

I It is also believed that the flow of air over and past the aerofoil-type control valve 30 33 will be substantially laminar in any open position of the valve and that, in consequence, there will be a substantial reduction in noise of operation of the unit as noise energy will be chinged from "casing break-out" towards the less critical direction of unit discharge. In addition, such laminar air-flow provides for a more even air distribution across the face area of the duct unit, or across a i' downstream heating unit (if provided) and it is considered such an electric heating unit may be fitted directly at the discharge end of the valve without the risk of overheating, in the element, due to uneven air distribution.

The dual duct shown in Figs. 8, 9 and 10 has a dual casing unit 42 with two inlet necks 44 leading to inlet passageways or opening 43, each of the dual casing units having an aerofoil-type control valve 29 as described above, each said valve having a control shaft 36 and a pressure sensor associated with it. A cold air supply is connected to one of the inlet necks 44 and a hot air supply is connected to the other of said necks. By controlling the operation of the two shafts 36 the two aerofoil-type valves 30 33 may be operated to vary the supply of cold and/or hot air to the iL -6space to be air-conditioned in response to the temperature in that space, the dual unit being capable of mixing the cold and hot air flows, and of controlling and maintaining any desired volume of air flow If desired, the dual duct variable air volume unit may be provided with an inherent air-flow measuring station which can inform a control system just how much air is being delivered at the outlet end of the dual duct so as to thereby maintain predetermined air-flow requirements.

Figs. 11, 12 and 13 illustrate a twin variable air volume terminal unit incorporating aerofoil-type air-control valves provided by this invention, said unit being designed for overhead installation. The unit has a twin casing 46 with two inlet openings, one of which indicated by the arrows C may be connected to a cold-air supply and the other indicated by the arrow D to a filtered room-temperature air supply. Inwardly of each said inlet opening is an aerofoil-type air flow control valve 29 and the 13. associated valve seatings 27/28, each of the valves 29 having a control rod or drive shaft 36 and a pressure sensor 40. There are two outlet openings 47 in this form of the unit and the two pressure sensors 40 are connected to an averaging static pressure sensor station, illustrated S* diagranmatically at 48.

The valve 29 for the room-temperature air supply D may operate in response to an inherent air-flow measuring station which provides a control system S" with information as to how much air is being delivered to the space to be air-conditioned in order to maintain preset or pre-determined maximum and minimum air-flow requirements. i This unit may be used to blend :room-temperature air with cold air so as to be used to control temperature in an air-conditioned space.

The twin duct unit is preferably a modular unit designed to clip on to the main duct system in the ceiling space of a building, so that if airconditioning requirements for a building need to be changed from time to time it is a relatively simply and inexpensive matter to do so.

Figs. 14, 15 and 16 illustrate a modified form of the unit shown in Figs. 11, 12 and 13. This unit is designed for installation beneath a flooring and it has the cold air and air-temperature air ducts 49 and separated that is to say, not in sandwich form and the air outlets are directed upwardly, as indicated by the arrows E. The two pressure sensors are connected to an averaging static pressure sensor station as mentioned with reference to Figs. 11, 12 and 13, indicated diagramnatical at 48.

It is to be understood that the aerofoil-type air-control valve may be used in other forms of unit through which air is to flow and wherein the flow i i -7of air is to be controlled. Also, it is believed the aerofoil-type valve may be found to be useful in controlling the flow of fluids other than air, such as water. However, we have not as yet investigated that matter and it may be that the design of the valve may require to be modified, particularly when used for controlling the flow of fluids which are heavier and/or more densv than gaseous fluids such as air.

It is also to be understood that different means for controlling the operation of the aerofoil-type valve may be provided, and that the design of the unit incorporating the aerofoil-type air-control valve may be modified to suit particular requirements.

All such modifications as come within the broad scope of the appended claims are to be deemed to be included within the ambit of the invention.

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Claims (18)

1. A unit having a fluid-flow regulator of aerofoil-type mountable in a duct and operable to expand leading edge parts of said regulator thereby to restrict fluid flow through the unit, or to retract said parts to permit increase of said flow.

2. A fluid-flow regulator of aerofoil form capable of varying the volume rate of flow in a duct wherein it is mounted, including means for expanding or retracting the regulator to vary the effective cross-section of said duct. 15/6/95LI7893.SP],3 -8- A 1in t h ,aving a fluid -flow regulator of aerofoil-type ;hich ma operated so as to expand the leading edge parts hereby restrict the flow of fluid through the unit perated so as to retract those leading edge parts an ereby permit an increased rate of flow of fluid throu e unit. 2. An air-flow unit ha an air-flow regulator of somewhat aerofoil design w 'may be expanded to restrict the flow of air through t -air-flow unit or retracted to permit an increased rate of flow of air through the umit.

3. A unit as claimed in Claim 1 or 2 and having a pair of n it- valve seatings so positioned and shaped that when the fluid-flow regulator is expanded to its fullest extent the regulator will bear upon the valve seatings substantially to shut off the flow of fluid through the unit.

4. A unit as claimed in Claim 3 wherein the valve seatings are located I on opposite inner side walls of the unit at positions equally *spaced from the inlet end of the unit, and each valve seating is ,lined with foam material to provide a resilient seating for the regulator. A unit as claimed in any one of the preceding claims wherein the S: regulator has two nose parts of arcuate shape which are hingedly connected together at their leading edges by hinge means positioned on an ois o 4Ve dA'-. substantially oe .jw..l li nef a internal

6. A unit as claimed in Claim 5 wherein each nose part is the shape of a cylindrical quadrant.

7. A unit as claimed in Claim 5 wherein each nose part is the shape of an elliptical quadrant.

8. A unit as claimed in any one of Claims 5 to 7 inclusive wherein the regulator has two tail parts which are hingedly connected together at their trailing edges and the leading edge of each tail part is cor a sr><d connected to the trailing edge of aAnose part in such manner that the composite nose and tail parts form a substantially aerofoil arrangement.

9. A unit as claimed in Claim 8 wherein each of the tail parts is substantially flat over the major part of its surface, A unit as claimed in either of Claims 8 or 9 wherein the two tail S/ parts are hingedly connected together at their trailing edges by r.f a hinge pin the opposite ends of which are slidable in slots -9- provided in the opposite inner side walls of the unit.

11. A unit as claimed in any one of Claims 5 to 10 wherein a control rod or drive shaft is mounted transversely within the unit between the two nose parts, with one end extending through one of the side walls of the unit and adapted to be connected to suitable drive means, and said control rod has means for effecting expanding and retracting movements of the nose parts.

12. A unit as claimed in Claim 11 wherein the means for effecting expanding and retracting movements of the nose parts consist of a pair of radius arms fastened to the drive shaft and a pair of links connecting the radius arm to the trailing edges portions of -tj air-flow regulator in such manner that when the drive shaft is turned in one direction the nose parts will be expanded outwardly and when it is turned in the opposite direction they will be retracted inwardly.

13. A unit as claimed in any one of the preceding claims wherein a pressure sensor is mounted within the unit. P 14. A unit as claimed in Claim 13 wherein the pressure sensor is mounted within the space occupied by the regulator. A unit as claimed in Claim 13 or Claim 14 wherein the pressure sensor is operable to provide a message to means for actuating the regulator when the flow of fluid through the unit- alters.

16. A unit as claimed in any one of the preceding claim wherein air- heating means is mounted adjacent to the outlet end of the unit.

17. A unit as claimed in Claim 16 wherein the air-heating means is an electrical heating unit.

18. An air-flow unit substantially as herein described with reference to and as illustrated in Figs. 1 to 7 of the drawings.

19. An air-flow unit substantially as herein described with reference to and as illustrated in Figs. 8 to 10, or Figs. 11 to 13 or Figs. 14 to 16 of the drawings. An aerofoil-type valve for use in controlling the flow of fluid through a passageway, substantially as herein described.

21. In an air-conditioning system, at least one unit,~ having an air- flow regulator, as claimed in any one of the preceding claims. DATD ITD ~jA B A* E HUR 1998 I, C L C 4c C it St tt C CC r I i rtC

22. A variable volume device for a valve for use in a rectangular duct of an air- conditioning system or the like and comprising: first and second valve members each being pivotal around an axis which in use is arranged to extend across a duct; each valve member being convex and of continuous plate-like form when viewed at right angles to the pivot axis; each valve member extending from its pivot axis in a downstream direction along the duct; actuating means provided for displacing the respective valve members towards or away from one another so as to move between open and closed positions of the valve; the actuating means being located in a zone generally between the valve members and comprising a rotatable shaft extending across-the valve duct 15 and adapted to be rotated when in use; the shaft carrying a pivotal linkage which is pivotally connected to the respective valve members; the valve members being such that in any open position air flow is guided by the valve members down the duct without interaction with the 20 actuating means; and each valve member having an elongated surface extending across the valve duct for contacting a wall of the duct when the device is in the closed position.

23. A variable volume device for a valve for use in a rectangular duct of an air- conditioning system or the like and comprising: first and second valve members each being pivotal around an axis which in use is arranged to extend across the duct; each valve member being of continuous convex plate-like form when viewed at right angles to the pivot axis; each valve member extending from its pivot axis in a downstream direction along the duct to a free end portion; actuating means provided for displacing the respective valve members 15/6/95LP7893.SPE,4 -11- towards or away from one another'so as to move between open and closed positions of the valve; the actuating means being located in a zone generally between the valve members and comprising a rotatable shaft extending across the valve duct and adapted to be rotated when in use; the shaft carrying a pivotal linkage which is pivotally connected to the respective valve members; the free end portion of each valve member being located downstream of the actuating means, whereby in any open position air flow is guided by the valve members down the duct without interaction with the actuating means; and the free end portion of. each valve member having an elongated surface for contacting a wall of the duct in the closed position. DATED this 16th day of t CELMEC INTERNATIONAL PTY. LTD. B itsPatent ttorney: c tI 0 it PETER NIC oLLS c 'i t C £C E~t June, 1995. IR An-,' 15/6/95P7893.SPRK ABSTRACT The invention provides a fluid-flow regulator of somewhat aerofoil-type which is so made that the nose-parts or leading-edge portion may be expanded to enlarged form to restrict the flow of fluid through a fluid-flow unit in which the regulator is installed or retracted to restricted or smaller frontal area to permit an increased rate of flow of fluid through the unit. I Ct *S c 'I I