Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F3/00—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems
  • F24F3/02—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the pressure or velocity of the primary air
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F1/00—Room units for air-conditioning, e.g. separate or self-contained units or units receiving primary air from a central station
  • F24F1/01—Room units for air-conditioning, e.g. separate or self-contained units or units receiving primary air from a central station in which secondary air is induced by injector action of the primary air

Definitions

• This invention relates to an air conditioning system, particularly, though not exclusively, for use in the heating/cooling and/or ventilating of buildings, particularly warehouses, offices, factories or the like, where air is delivered through a ductwork system to air mixing devices.
• the invention also relates to an air conditioning method, particularly using said air mixing devices.
• An object of the invention is to provide an improved air conditioning system and air conditioning method.
• an air conditioning system comprises an air mixing device having a duct with respective inlet and outlet ends, and a convergent nozzle device disposed outside of the duct and having an outlet end thereof spaced upstream of the duct inlet end, so that, in use, primary air supplied through said nozzle device discharges from the nozzle device outlet end and entrains air therearound, the resultant mixture, forming secondary air, passing along said duct from its inlet end to its outlet end where there is discharge of said secondary air.
• a method of air conditioning comprises supplying primary air to an air mixing device having a convergent nozzle device and a duct, the duct having respective inlet and outlet ends and the nozzle device being disposed outside of the duct with an outlet end thereof spaced upstream of the duct inlet end, said primary air discharging from the outlet end of the nozzle device and entraining air therearound, the resultant mixture, forming secondary air, passing along said duct from its inlet end to its outlet end, where said secondary air is discharged.
• Figure 1 is a perspective view of an air mixing device of an conditioning system of the invention
• FIG. 2 is an enlarged, partly cut-away more detailed view of part of the device of Figure 1, with possible additional features shown,
• Figure 3 is an enlarged, detailed view of a nozzle of the device.
• Figure 4 shows an example of an air mixing device incorporated in an air conditioning system in a building
• FIG. 5 schematically shows an air conditioning system of the invention.
• the air conditioning system of the invention is primarily intended for use in industrial buildings, where primary air is supplied under high pressure along small diameter ducting to a plurality of air mixing devices, each having an outlet nozzle.
• Figure 1 shows a mixing device of an air conditioning system of the invention, the device having an entry section for 'primary' ductwork air, the entry section being formed of a short circular-section duct 10 integral with a transition piece 11, the internal and external cross-section of which changes from circular to rectangular along its length.
• the transition piece 11 is connected to a front face of a rectangular backplate 12a of a nozzle 12 of the mixing device, the backplate having a rectangular aperture therethrough shaped to correspond to the connected rectangular end of the transition piece, but slightly smaller than if so that a seal is formed around it.
• each side plate Fixedly secured to the rear face 13 of the backplate are two vertical side plates 14 which extend normally away from the face 13 slightly outside the shorter sides of the aperture respectively.
• Each side plate has its free end bent outwardly through 90° to form a flange 14a and each flange 14a has vertically aligned upper and lower elongate slots 15, 16 respectively therein.
• a pair of adjustable top and bottom plates 17, 18 respectively are connected by hinges 19 to the rear face 13.
• the hinges are sealed to the rear face 13 and respective rubber edge seals 20 are provided at the side edges of both plates 17, 18 to seal against respective inner surface of the side plates 14.
• the top and bottom plates 17, 18 are turned through 90° away from each other, and the respective outwardly turned flanges 21, 22 so formed have respective pairs of holes at their extended opposite ends for reception of bolts 23.
• the bolts pass through respective soft rubber washers between the flanges 21, 22 and the flanges 14a, and then pass through the slots 15, 16 as shown in Figure 3, to carry respective nuts (not shown).
• the nuts can be loosened to allow the top and bottom plates to be adjusted up or down to vary the size of the nozzle, the nuts then being tightened to provide a rigid assembly.
• primary air from the circular ductwork of a building passes through the entry section and then into the nozzle through its aperture. Variation of the nozzle size alters the volume and velocity of the primary air passing therethrough. This adjustability of the nozzle size is a particularly advantageous feature of the air mixing device.
• the primary air discharging from the nozzle expands, its volume increasing as it diverges and induces/entrains air from the surrounding space, as will be described.
• the backplate of the nozzle is rigidly connected to a elongated, rectangular section of ducting 24 by four corner angles 25, the outlet of the nozzle being spaced some way upstream of the inlet of the ducting 24, as shown in Figure 2.
• the space between the corner angles 25 from the nozzle backplate to the ducting inlet is covered on all four sides by a metallic, open mesh 26 having a high free area.
• the 'mesh' can take any suitable alternative form from that shown and includes within its scope any air permeable 'cover' over and around the nozzle end.
• the ducting 24 has at its outlet end a discharge head 27 which can be adjustable to vary the angle of discharge from the ducting 24, e.g. to distribute air to ground level.
• the discharge head has an outlet grille 28 at its outlet end and it can also have airflow control blades 29 disposed between its ends.
• the blades 29 can be horizontally adjustable.
• the outlet grille can have adjustable horizontal or vertical blades 30.
• insulation material 31 with or without a moisture barrier, can be fitted to the outside of the ducting 24, preferably on all outer faces.
• sound attenuation material 32 can be fitted to the inside of the ducting, preferably on all inner faces.
• FIG. 33 indicates an adjustable damper to control the volume of air supplied.
• the damper can be manually or motor operated.
• Numeral 34 indicates an air filter for filtering the induced airstream and numeral 35 indicates a heating or cooling coil for altering the temperature of the induced air.
• any combination of the treatment devices can be used or only one can be used.
• An opening can be provided in the mesh for fitting the or each device, or the or each device can be fitted with the mesh remaining.
• This treatment facility is another particularly advantageous feature of the air mixing device.
• the mixed or secondary air is limited in its expansion as it discharges into the rectangular section of ducting 24.
• a facility has been incorporated to streamline the air for even airflow over the ducting section.
• the dimensions of the containment ducting 24 and the nozzle size are calculated to provide the required supply air stream for discharge into the building , containing the air conditioning system.
• the secondary air discharges through the discharge head 27 at the required angle by adjustment of the head 27 ' , the width of which will vary with throw and air volume.
• nozzle and/or ducting can be used, to suit the volume of secondary air required to discharge into any particular area of the warehouse, office, factory or the like.
• the induction box with the discharge grille attached would normally be at high level in the building, discharging the air to ground level.
• the assembly could be located in a ceiling or wall or even discharge at low level.
• a circular aperture could be provided in the nozzle backplate.
• Figure 4 schematically shows a primary air distribution duct 47 supplying treated primary air to the nozzle 12 of an air mixing device fitted high in a building 40.
• the nozzle is shown in simple, non-adjustable form, but this would in practice be as in Figures 2 and 3, with mesh around it and with its outlet upstream of the ducting 24 which has a discharge head 27.
• a fresh air intake duct 60 can be located in the roof 62 or a wall of the building, the fresh air preferably passing through an air filter 34, adjustable damper 33 and possibly a heating or cooling coil, such as coil 35.
• the fresh air around the nozzle device outlet end is entrained as with the surrounding space air described.
• the system incorporates an intake duct 62 for induction of mixing air from a low level in the building 40.
• the duct 62 can incorporate any one of air filter 34, coil 35 and damper 33 alone or in combination.
• the duct 62 could replace intake duct 60 together with its damper 33 and filter 34 or could be used with it as shown.
• a supply diffuser 61 can be fitted at the end of the ducting 24, for both heating and cooling applications.
• This diffuser incorporates a device which changes the performance of the diffuser for heating or cooling.
• said device is a fluid which expands or contracts to initiate operation of an actuating rod which raises or lowers the diffuser blades to change the diffuser performance.
• a different temperature sensitive means could be used.
• the airflow from its discharge end requires greater penetration to ground level to overcome the rising effect of heated air, as compared with that required for cooling.
• the fitting of the diffuser with a temperature sensing device which changes the discharge air flow performance,maintains the required comfort conditions for both heating and cooling.
• Figure 5 shows a complete air conditioning system layout for heating or cooling a space, the system having said primary air handling unit 50 which can incorporate one or both different heating or cooling sources 45, 44 respectively.
• To transfer the conditioned primary air from the unit 50 is circular section ductwork 48, this distributing the primary air to the mixing devices of Figures 1 to 3, denoted here by the numeral 49.
• the primary air is mixed with induced secondary air from the space where the devices 49 are fitted, the resultant mixture being discharged into the conditioned space.
• the heating and cooling sources are indirect in nature, so that the medium which conditions the primary air does not mix with it, and heat transfer to or from the primary air occurs by way of it passing across the containment for the heating or cooling medium. Accordingingly any poisonous gases and/or solid particles resulting from combustion to provide the heating source are not discharged into the space, leading to improved air quality therein.
• Various sources for heating or cooling can be used. Examples are: indirect gas or oil fired heating, hot water coils, steam coils, thermal oil coils, chilled water coils, coils containing refrigerant and cross flow air to air heat exchangers 42.
• the primary air handling unit has a mixing box 46 that may or may not be in air flow communication with heat exchanger 42 and/or a fan 41 to extract and/or recycle air from the space or elsewhere.
• the air entering the treatment part of the unit 50 may thus be 100% fresh air or 100% recirculated air or any proportion of fresh and recirculated air.
• From the mixing box 46 the primary air can be filtered at 51 and humidified or de-humidified at 43/44.
• the heated or cooled primary air is distributed along the ductwork 48 by a primary fan or blower 47.
• the spiral wound ductwork 48 may or may not be insulated, this being dependent upon the air condition within the ductwork and the conditioned space.
• the primary air temperature as a result of heating whilst passing through the unit 50, will preferably be in the range of 30°C to 100°C.
• the primary air will preferably be supplied from the unit 50 with a temperature with a temperature in the range of 3°C to 15°C.
• the air conditioning system has a control panel (not shown) to maintain the desired air conditions within the space by way of sensors or thermostats.
• the adjustability of the nozzle of the air mixing device allows its area to be changed relative to the fixed area of the ducting 24.
• the induction effect can be modified by changing the relationship between the two areas, the spacing of the nozzle outlet upstream of the ducting inlet allowing mixing of the primary and secondary air prior to entering the ducting.
• the induction effect can thus be modified by this adjustability of the nozzle, in contrast to the results obtainable from a fixed area nozzle.
• the adjustability allows for improved setting of induction rates within a building for altering airflow conditions to meet design requirements and modifying airflow conditions that may be required by change of building use.
• the air conditioning system When the air conditioning system is used for cooling, it is more efficient to induce cool air from a low level in the building than to induce warmer air at high level therein, for example by use of duct 62. This provides a cooler, lower zone in the building where cooling is required.
• a thermostat can be located at low level in the building, and if high level warm air were to be induced and the mixture discharged to low level, the thermostat would call for additional cooling.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Central Air Conditioning (AREA)
• Air Conditioning Control Device (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10677313

Family Applications (1)

Country Status (5)

Families Citing this family (8)

Family Cites Families (7)

• 1990
  • 1990-06-08 GB GB909012845A patent/GB9012845D0/en active Pending
• 1991
  • 1991-06-05 GB GB9112094A patent/GB2244804B/en not_active Expired - Fee Related
  • 1991-06-05 WO PCT/GB1991/000898 patent/WO1991019135A1/en not_active Application Discontinuation
  • 1991-06-05 AU AU79508/91A patent/AU7950891A/en not_active Abandoned
  • 1991-06-05 CA CA2084753A patent/CA2084753A1/en not_active Abandoned
  • 1991-06-05 EP EP91910550A patent/EP0531412A1/de not_active Withdrawn

Non-Patent Citations (1)

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