具体实施方式：
[0045]Embodiments generally relate to a gaming table. In particular, embodiments relate to a gaming table providing an air curtain feature to shield a dealer position from fumes such as Environmental Tobacco Smoke (ETS) emanating from a player side of the table.
[0046]FIGS. 1 to 10 and 11A to 11E show details of a gaming table 100 according to some embodiments. Generally, the gaming table 100 comprises a table structure 101 with a dealer side 105 and a player side 106 that are opposite one another and encompass the playing surface of the table. In other words, a dealer sits or stands on the dealer side 105 and faces the player side 106, while the players sit or stand on the player side 106 and face the dealer side 105. The gaming table 100 may be used to play card games, the outcome of which may be the subject of a wager, for example. In some embodiments, the gaming table 100 is particularly suitable for use in playing the game baccarat, although the gaming table 100 may be used for playing other games instead. However, in other embodiments, the gaming table (or various features or functions thereof relating to air curtains or shielding) may be used for other games that do not involve the use of cards but that nonetheless have a dealer area that can be shielded from a player area.
[0047]The table structure 101 has an upper table surface that defines: a player area 103 on the player side 106, upon which players may place tokens, cards or other game items; and a dealer area 104 on the dealer side 105. The dealer side 105 defines a recessed area to act as a dealer position 110, where the dealer can sit or stand while conducting the play of the game. The dealer position 110 is recessed into the dealer area 104 sufficiently to allow the dealer to reach to his or her left and right into the dealer areas 104 on either side and also reach forward into the player area 103. The player area 103 is defined at least in part by an outer boundary 102, such as a cushion or other form of boundary, on the player side 106 and by the adjacent dealer area 104 on the other side.
[0048]The dealer area 104 and player area 103 together make up all or almost all of the table surface area. However, the surface areas of the dealer area 104 and player area 103 are not necessarily the same. A boundary between the dealer area 104 and player area 103 may be defined by a demarcation line or a surface transition, such as a transition of one material to another (i.e. a felt area transitioning to a wood or vinyl area). Alternatively, the boundary may be notional, rather than physical and may not be visibly defined. In the example shown in FIG. 1, the player area 103 is demarcated and visibly distinguished from the dealer area 104 by a physical or notional straight line that extends laterally across the table 100 upper surface from an area where the outer boundary 102 starts on one lateral side and finishes on the other lateral side. In some embodiments, the boundary may not be straight. For example, the boundary may be curved, as is shown in the embodiment of FIG. 12A. The boundary may be defined such that the area where the cards are laid by the dealer is in the player area, even those cards played by the dealer, while the dealer area 104 corresponds to the dealer's personal proximity (well within the dealer's personal reach without leaning forward) where the card shoe is positioned, the house betting chips are positioned and other dealer-only-access pieces, token or equipment is positioned.
[0049]The gaming table 100 is designed to facilitate the creation of an air curtain in front of the dealer position 110 in order to insulate and protect the dealer from fumes, such as fumes from e-cigarettes or other vapour-producing devices, or ETS emanating from the player side 106, for example due to one or more players smoking tobacco or using non-tobacco fume or vapour-producing products. For this purpose, the gaming table 100 provides various structures and components to generate air flows around the gaming table 100 and in particular around the dealer position 110. These air flows are described in further detail below.
[0050]The gaming table 100 comprises at least two air manifolds positioned on an upper surface of the table and the dealer area 104 to generate air flows above the table surface that are directed generally in front of and away from the dealer position 110 in order to shield the dealer from fumes or ETS emanating from the player side 106. These air manifolds may include a first air manifold 120, a second air manifold 140, and optionally a third air manifold 160. The first and second air manifolds 120, 140 are positioned respectively on opposite sides (to the left and right) of the dealer position 110. Each of the first and second air manifolds 120, 140 defines a series of apertures 121, 141 from which air jets 122, 142 can be projected above the table surface in various directions.
[0051]Some prior air curtain arrangements direct air straight up in a vertical air wall from a long continuous line extending in between the dealer position and the player side, which can be disruptive or uncomfortable to players and/or dealers. This is because the upward air wall on the dealer side tends to make the dealer's hands cold and it can be annoying for the dealer to have to pass her or her hands and/or cards through while conducting the game. Such upward air walls can also have the undesired effect of causing the cards to flip as they are dealt, which can inadvertently reveal cards that are intended to remain secret. Further, air vents extending in a long continuous line tend to have significant pressure variations along the line of the vent, which can lead to the air wall having inconsistent air velocities and being uneven and less effective in directing fumes or ETS away from the dealer position.
[0052]Embodiments disclosed herein direct air in a different way from the mentioned vertical air wall arrangements, without using an air vent that extends in a long continuous line, and instead creating an air barrier in front of the dealer position that is created by air jets 122, 142 directed from each lateral side of the dealer position. The air jets 122, 142 from the two main laterally spaced air manifolds 120, 140 are generally not directed toward the table surface and generally are not projected with enough speed to be disruptive to the placement or handling of cards in the main playing surface between the dealer and the player positions. The air jets projecting from the first and second air manifolds are generally directed at an upward angle away from the table surface and in an arc excluding the direction (and angular range) toward the dealer position 110 from the respective manifold. The jets 122, 142 thereby form a barrier that tends to entrain any fumes or ETS emanating from the player side 106 (and even emanating from areas around the left and right sides of the table) and direct such air with entrained fumes or ETS upwardly and away from the dealer position 110. Combined with low pressure clean air emanating from the table structure 101 under the table surface on the dealer side 105, the effect of the air jets is to shield the dealer position from potentially harmful fumes or ETS from the player side 106 by restricting air from flowing from the player side 106 into the dealer side 105.
[0053]In addition to the air manifolds 120, 140, 160 positioned on or above the table surface to effectively provide upper air flow direction means, the table structure 101 has lower air flow direction structure, for example in the form of walls defining apertures and plenums and including grates, to direct clean air from under the table structure on the dealer side 105 toward where the dealer's head would be when seated or standing at the dealer position 110. The lower air flow direction structure aims to generate a positive air pressure from around the floor level and in the leg recess at the dealer position so that stale air does not accumulate in the lower areas at the rear of the table, thereby continuously flushing out the air from the floor level upwards so that the air can be extracted from ceiling level to filter and clean it. Rather than filtering and cleaning the air extracted from the environment, it may be simply exhausted from the environment without being re-used or recycled. For environments permitting smoking, it is beneficial to have frequent turnover of air through the whole environment in order to limit or minimise adverse health effects on workers working in or passing through that environment. According to some embodiments, the ventilation system for such environments can cause the entire volume of air in the room or area to be replaced with fresh air roughly every 1 to 5 minutes, for example about every 2 minutes or about 25-30 times per hour.
[0054]Referring to FIG. 1, a plan view of a gaming table 100 is shown according to some embodiments. The gaming table 100 comprises a table structure 101 having a dealer side 105 and a player side 106 as described above, and defining a dealer position 110 as described above.
[0055]The gaming table 100 comprises a first manifold 120 positioned on the upper surface 109 of the table 100 to the left of the dealer position 110 and a second manifold 140 positioned on the upper surface of the table 100 to the right of the dealer position 110. The first and second manifolds 120, 140 may be positioned at similar or different distances from the dealer position 110 and similar or different distances from a rearmost edge of the table 100. For example, the first and second manifolds 120, 140 may be positioned slightly forward of the dealer position 110 towards the left and right sides of the table 100 respectively. The gaming table 100 may further comprise a third manifold 160 which may be positioned to extend vertically upward from the upper surface 109 of the table 100 to the left of the dealer position 110.
[0056]Each of the manifolds 120, 140, 160 may be supplied with pressurised air and comprise apertures 121, 141, 161 configured to form air jets 122, 142, 162 having various characteristic velocities and emanating from the apertures 121, 141, 161 above the upper surface 109 of the table 100. The characteristic velocities of the air jets 122, 142, 162 may comprise different magnitudes and directions which are selected such that the air jets 122, 142, 162 form an air curtain or barrier by entraining air from the player side 106 and transporting the entrained air upwards and away from the dealer position 110 by advection. Air from the dealer side 105 may also be entrained by the air jets 122, 142, 162 and transported away from the dealer position 110 in a direction which is generally towards the player side 106 and upwardly away from the upper surface 109 of the table 100.
[0057]An indication of the magnitude and direction of the characteristic velocities as well as the spread of the air jets 122, 142, 162 is given by arrows emanating from the manifolds 120, 140, 160 shown from a top perspective in FIG. 1, from a rear perspective in FIG. 2, and from a side perspective in FIG. 3. Certain jet characteristics may be achieved with careful design of the manifolds 120, 140, 160, particularly the shape, configuration, position and orientation of each of the apertures 121, 141, 161. Exemplary configurations of the manifolds 120, 140, 160 are shown in FIGS. 7 to 11, which have been designed for a particular application and are described in detail below.
[0058]The table 100 may comprise a number of low pressure outlets below table top level to provide fresh clean air to the dealer side 105. The low pressure outlets may comprise a number of panels or grilles 180 with apertures 181 in side walls 116 of the table structure 101 to form relatively low pressure air jets 182 emanating from the side walls 116. That is, air jets 182 may be formed with a relatively low pressure differential and have relatively low characteristic velocities compared with the pressure differentials and characteristic velocities of the above table air jets 122, 142, 162. Some of the low pressure air jets 182a and 182b may be directed into the dealer position 110 from the left and right sides respectively. Other low pressure air jets 182c and 182d may be directed rearwards from the back of the table structure 101 on the left and right sides respectively in a direction away from the player side 106.
[0059]In some embodiments, the pressure differential across the low pressure outlets may not be sufficient to form well defined air jets, and instead, the air may flow out from the outlets at low velocity without forming a clearly defined jet.
[0060]Referring to FIG. 2, a rear elevation of the table 100 is provided showing the table 100 from the dealer side 105. The table 100 is shown installed on a floor 201. The low pressure outlets may comprise a skirting board 210 just above floor level near a bottom of one or more of the side walls 116 and define a plurality of apertures 211 configured to form the low pressure jets 182. For example, a left side skirting board 210a may be configured to form the left side rearward air jets 182c and a right side skirting board 210b may be configured to form the right side rearward air jets 182d. The skirting boards 210 may be approximately 100 mm high, for example. The apertures 211 may comprise vertical slots with a height of approximately 80 mm and a width of approximately 5 mm spaced horizontally at about 50 mm centres, for example. The low pressure air jets 182c, 182d may have characteristic velocities of approximately 0.5 m/s measured at a distance of about 100 mm away from the skirting boards 210a, 210b respectively.
[0061]The low pressure outlets may further comprise one or more grilles 220 disposed in the side walls 116 adjacent the dealer position 110 (see FIGS. 5 and 6). The grilles 220 may include a plurality of apertures 221 configured to form the low pressure air jets 182a and 182b directed to the dealer position 110. The apertures 221 may be located at a range of heights above floor level and each grille 220 may cover a certain area of the side wall 116 on which it is disposed. For example, a left side grille 220a may be configured to form the left side air jets 182a directed towards the dealer position 110, and a right side grille 220b may be configured to form the right side air jets 182b directed towards the dealer position 110. The apertures 221 may comprise vertical slots with a height of approximately 100 mm and a width of approximately 5 mm spaced horizontally at about 15 mm centres and spaced vertically at about 110 mm centres, for example. The grilles 220a, 220b may each cover an area approximately 500 mm high and 350 mm wide. In some embodiments, the grilles 220a, 220b may comprise a perforated plate mounted behind the slots. The perforated plate may be approximately 50% open, for example. The low pressure air jets 182a, 182b may have characteristic velocities of approximately 0.2 m/s measured at a distance of 50 mm away from the grilles 220a, 220b respectively.
[0062]In use, clean fresh air supplied from the low pressure air jets 182 may provide positive pressure in and around the dealer position 110 and subsequently be drawn upwards over and around the dealer position 110, entrained by the high pressure air jets 122, 142, 162 and carried upwards and away from the dealer position 110 in a direction towards the player side 106, thereby restricting air, fumes or ETS from the player side 106 from moving to the dealer position 110 and providing a local environment in the vicinity of the dealer position 110 containing the clean fresh air supplied by the low pressure air jets 182.
[0063]The table 100 may further comprise a cabinet 214 formed in the table structure 101 below table level (i.e., below the table surface) in front of the dealer position 110. The cabinet 214 may comprise one or more hinged doors and an interior storage space.
[0064]Referring to FIG. 4, a plan view of the gaming table 100 is shown according to some embodiments, illustrating part of the lower structure below the level of the table surface 109. The table 100 may comprise a base panel 404 positioned just above floor level to divide the space within the side walls 116 into a first plenum 420 (see FIG. 6) and a second plenum 430. The first plenum 420 may comprise a space formed between the floor 201 and the base panel 404, and the second plenum 430 may comprise a space formed above the base panel 404 and below the upper table surface. Referring to FIG. 6, the first plenum 420 may further comprise a space to the left of the dealer position 110 bounded by a left side inner wall 422 and one or more of the side walls 116. The first plenum 420 may also further comprise a space to the right of the dealer position 110 bounded by a right side inner wall 424 and one or more of the side walls 116. The inner walls 422, 424 may be spaced from the side walls 116 by a distance of approximately 50 mm, for example. Both the first and second plenums 420, 430 may extend around the dealer position 110 within the table structure 101 from the left side to the right side.
[0065]The floor 201 may include one or more air outlets 401 to provide fresh clean air to the first plenum 420. The air outlets 401 may have a diameter of approximately 200 mm, for example. The pressure in the first plenum 420 may be substantially lower than pressure developed in the manifolds 120, 140, 160, but relatively higher than the pressure developed in the second plenum 430. The first plenum 420 may supply air to the low pressure outlets to form the low pressure air jets 182.
[0066]The base panel 404 may define an inlet 410 configured to allow air to flow from the first plenum 420 to the second plenum 430. The inlet 410 may also provide access to run electrical or communications cables from within the table structure 101 to the floor 201. The inlet 410 may have a diameter of approximately 75 mm, for example. The base panel 404 may further comprise a left side aperture 412 and a right side aperture 414 to allow the first plenum 420 to extend above the base panel 404 and include the spaces bounded by the side walls 116 and the inner walls 422, 424 respectively.
[0067]Referring to FIG. 5, a further illustration of the structure of the gaming table 100 below table level shows a high pressure system 501 configured to supply the manifolds 120, 140, 160 with pressurised fresh air (from a source, such as an external source, outside of the gaming environment in which the table 100 is positioned) having a pressure substantially higher than that in the first and second plenums 420, 430.
[0068]The high pressure system 501 comprises a blower 505, which may be in the form of a compressor or fan. The blower 505 may be configured to draw clean fresh air from the second plenum 430 and increase the pressure of the air to supply pressurised air to the manifolds 120, 140, 160 via a network of conduits. The conduits may comprise rigid and/or flexible conduits suitable for supplying pressurised air to the manifolds 120, 140, 160 at the required pressure and flow rate.
[0069]For example, the network of conduits may comprise a rigid conduit network 530 connected to the fan 505 by a connector conduit 532 at connection point 534. The location of the connection point 534 in the rigid conduit network 530 may be selected to balance the pressure required at the different manifolds 120, 140, 160 against the distance between each manifold 120, 140, 160 and the blower 505 to account for any pressure losses in the conduit network to allow a single blower 505 to be used to supply all of the manifolds 120, 140, 160 simultaneously.
[0070]Each air distribution manifold 120, 140, 160 may have an associated high pressure outlet 520, 540, 560 connected to the rigid conduit network 530 by associated lengths of flexible conduit 522, 542, 562 respectively. Each length of flexible conduit 522, 542, 562 may be connected to the rigid conduit network 530 by connectors 536. For example, the rigid conduit network 530 may be formed of PVC pipe with a diameter of around 80 mm, and the lengths of flexible conduit 522, 542, 562 may be formed of flexible plastic ducting with a diameter of around 65 mm. The connectors 536 may comprise adapters to transition between different diameters, and further adapters may be used at the high pressure outlets 520, 540, 560 if further diameter transitions are required.
[0071]Referring to FIG. 6, the gaming table 100 is shown from a rear perspective, illustrating the position of the first and second plenums 420, 430, the low pressure outlets 180, the high pressure system 501, and the high pressure outlet manifolds 120, 140, 160. As discussed previously, the first plenum 420 extends along the floor 201 under the base panel 404, up through the left and right side apertures 412, 414 and alongside the left and right side walls 116 adjacent the dealer position 110 between the side walls 116 and the left and right side inner walls 422, 424. The first plenum 420 receives clean fresh air from an under floor supply through the air outlets 401 (see FIG. 4) at a pressure which is higher than ambient pressure in the room (or the immediate environment of the gaming table 100). The air may be supplied at the air outlets 401 at a pressure of approximately 180 Pa above ambient pressure in the room with a temperature of approximately 22.5° C. and a relative humidity of approximately 45-50% at a flow rate of approximately 30 L/s per square metre of floor area, in one non-limiting example. Air may be supplied at other pressures, temperatures, relative humidities and flow rates, depending on local requirements. Air from the first plenum 420 then flows through the apertures 211, 221 in the skirting boards 210 and grilles 220 to provide fresh clean air to the dealer position 110 and rear of the table 100 on the dealer side 105. The air flow rate through each skirting board 210a, 210b may be approximately 35 L/s and the air flow rate through each of the grilles 220a, 220b either side of the dealer position 110 may be approximately 25 L/s, for example.
[0072]The first plenum 420 also supplies clean fresh air to the second plenum 430 through the inlet 410 in the base panel 404. The average air pressure in the second plenum 430 may be similar to or less than the average air pressure in the first plenum 430 and may be similar to or greater than the ambient pressure in the room. For example, the average air pressure in the second plenum 430 may be in the range of about 0 Pa to 30 Pa above the ambient pressure in the room. The second plenum 430 extends around the dealer position 110 within the side walls 116 above the base panel 404 and below table top level. The clean fresh air in the second plenum 430 is then drawn into the blower 505 and pressurised to supply the manifolds 120, 140, 160 with relatively high pressure clean fresh air via the high pressure system 501. The blower 505 may increase the static pressure of the air by an amount in the range of about 180 Pa to 300 Pa, for example, to provide a static pressure in the high pressure system 501 and the manifolds 120, 140, 160 in the range of about 360 Pa to 480 Pa above ambient room pressure, for example. The flow rate through the blower 505 may be in the range of about 11 L/s to about 15 L/s for example.
[0073]In some embodiments, the blower 505 may be configured to draw clean fresh air over or around heat generating equipment positioned within the second plenum 430 before pressurising the air. The heat generating equipment may be grouped together at a particular location within the second plenum 430 adjacent a flow path of the clean fresh air from the inlet 410 to the blower 505. Such an arrangement may provide the advantages of cooling the equipment and heating the air supplied to the manifolds to a temperature which is more comfortable for the dealer and players than if the air had not been heated. Air may exit the manifolds 120, 140, 160 at a temperature in the range of approximately 16 to 24 degrees C., for example. The temperature of the air exiting the manifolds may be controlled by a computerised control interface 1660 on computing device 1630/1650 issuing commands to an air curtain controller 1610 (FIG. 16). The temperature may be selected or adjusted to be different at different times of year and/or depending on the ambient room conditions or outside air temperature.
[0074]High pressure air jets 122, 142, 162 are then formed by the pressurised air flowing through the manifolds 120, 140, 160 and particularly through the apertures 121, 141, 161 in the manifolds 120, 140, 160. The high pressure air jets 122, 142, 162 are configured to form an air curtain or barrier which restricts air fumes or ETS from the player side 106 from being transported to the dealer position 110. This is achieved by configuring the high pressure air jets 122, 142, 162 to entrain air fumes or ETS from the player side 106 as well as fresh clean air from the dealer side 105 and dealer position 110 and transport the entrained air upwards above the player side 106 and away from the dealer position 110 and/or dealer side 105. This effect may be controlled or enhanced by drawing air out of the environment 1300 through at least one exhaust vent 1310 in the room (see FIG. 13) to draw stale air up and away from the dealer position. Such an exhaust vent 1310, optionally assisted by a fan (not shown) may be positioned on a wall or ceiling of the room/environment 1300 at a location above the player side 106 or beyond the player side 106 in a direction away from the dealer position 110 or dealer side 105. The exhaust vent 1310 may draw air from the environment 1300 at a flow rate equal to the flow rate of air supplied through the air outlets 401 in the floor 201, such as a flow rate of approximately 30 L/s per square metre of floor area, for example.
[0075]The manifolds 120, 140, 160 will now be described in further detail according some embodiments, with reference to FIGS. 7 to 11. It should be noted that numerous manifold configurations may be effective in any given application. However, the manifolds described here illustrate one exemplary configuration designed for a particular application according to some embodiments.
[0076]Referring to FIG. 7, manifold 120 is shown in further detail according to some embodiments. Manifold 120 comprises a dome shaped wall 123 defining an outer surface 124, an inner surface 125 defining a manifold plenum 126, and a plurality of apertures 121 extending between the inner surface 125 and the outer surface 124. The apertures 121 may alternately be referred to as channels, passages or nozzles. In some embodiments, the apertures 121 may comprise circular cylindrical passageways as shown in the drawings. In other embodiments, the apertures 121 may comprise different geometries or structures configured to achieve certain selected jet characteristics, such as a tapered nozzle, for example.
[0077]The outer diameter of the dome shaped wall 123 may be approximately 120 mm. The inner diameter of the wall 123 may be approximately 60 mm. The apex of the outer surface 124 is approximately 45 mm away from the upper surface 109 of the table 100. The thickness of the wall may be approximately 30 mm. The length of the channels or apertures 121 may be approximately 30 mm. In various embodiments, these dimensions may be adjusted to any suitable dimensions or proportions appropriate for a desired jet configuration. In particular, the length of the channels or apertures 121 may be selected to provide a suitable level of air flow stabilisation prior to the air issuing from the apertures 121 and forming the jets 122. Similar considerations apply for all of the manifold apertures 121, 141, 161.
[0078]The dome shaped wall 123 may be formed using additive manufacturing such as 3D printing, or cast or injection moulded to form the wall 123 and then drilled to form the apertures 121, for example. The manifold 120 may be formed of any suitable material with sufficient dimensional stability to maintain the dimensions and geometry required to form jets 122 with appropriate characteristics.
[0079]In use, pressurised air supplied from the high pressure system 501 enters the manifold plenum 126 via the high pressure outlet 520 where the desired level of pressure is developed, thereby forcing the clean fresh air through the apertures 121 to form the jets 122.
[0080]An exemplary configuration of the apertures 121 is shown in FIGS. 8A to 8D with the relevant dimensions listed below in Table 1. There are five apertures 121 shown in FIGS. 8A to 8D marked as 8N1 through to 8N5 and listed in Table 1. The axes shown are oriented such that the positive z-axis is vertical and extends perpendicularly away from the upper surface of the table 100, the positive x-axis extends in a direction from the left side of the table 100 towards the right side of the table 100, and the positive y-axis extends in a direction from the dealer side 105 towards the player side 106. A similar convention is used in relation to FIGS. 9 to 11 as well.
[0081]FIG. 8A shows a right side elevation of manifold 120. The angles provided represent the angle between a central axis of each aperture 121 and the horizontal xy-plane measured in a direction towards the vertical z-axis and are listed in Table 1 as the elevation angles.
[0082]FIG. 8B shows a top plan view of manifold 120. The angles provided represent the angle between a central axis of each aperture 121 and the horizontal positive x-axis measured in a direction towards the horizontal y-axis and are listed in Table 1 as the azimuth angles.
[0083]FIG. 8C shows a right side elevation and FIG. 8D shows a top plan view of the manifold 120 illustrating the diameters of the apertures 121 in millimetres. The manifold 120 may further comprise a directional indicator marking or lug 128 configured to indicate the intended orientation of the manifold 120 and apertures 121 with respect to the gaming table 100. For example, in the exemplary embodiment, the manifold 120 should be oriented with the indicator lug 128 pointing rearward of the table 100 in a direction from the player side 106 towards the dealer side 105.
[0084]The configuration of the apertures 121 may result in the formation of a particular set of air jets 122 having particular selected characteristic velocities and/or other desired characteristics. Each of the apertures 121 varies in elevation and azimuth from other apertures 121 in the same manifold and may have a same or different diameter as another aperture. For example, the air jets 122 may be configured as shown in FIGS. 1 to 3 with air jets 122a, 122b, 122c, 122d and 122e corresponding to apertures 8N1 to 8N5 as shown in Table 1.
TABLE 1ApertureelevationazimuthDiameternumberJet(degrees)(degrees)(mm)8N1122a10226688N2122b769388N3122c428788N4122d2624.58N5122e254510
[0085]Manifold 140 is connected to the high pressure system 501 and comprises a similar dome structure, as described in relation to manifold 120 and FIG. 6, which may comprise materials and be formed as described in relation to manifold 120. In use, pressurised air supplied from the high pressure system 501 enters a manifold plenum 146 of the manifold 140 via the high pressure outlet 540 where the desired level of pressure is developed thereby forcing the clean fresh air through the apertures 142 to form the jets 142.
[0086]An exemplary configuration of the apertures 141 is shown in FIGS. 9A to 9D with the relevant dimensions listed below in Table 2. There are 8 apertures 141 shown in FIGS. 9A to 9D marked as 9N1 through to 9N8 and listed in Table 2. The axes shown are oriented as described with reference to FIGS. 8A to 8D and a similar convention is used to define the elevation angles, azimuth angles and dimensions.
[0087]The configuration of the apertures 141 may result in the formation of a particular set of air jets 142 having particular selected characteristic velocities and/or other desired characteristics. Each of the apertures 141 varies in elevation and azimuth from other apertures 141 in the same manifold and may have a same or different diameter as another aperture. For example, the air jets 122 may be configured as shown in FIGS. 1 to 3 with air jets 142a, 142b, 142c, 142d, 142e, 142f, 142g and 142h corresponding to apertures 9N1 to 9N8 as shown in Table 2.
TABLE 2ApertureelevationazimuthDiameternumberJet(degrees)(degrees)(mm)9N1142h10530489N2142g804489N3142f637389N4142e348169N