AU2010100700B4 - Air conditioning - Google Patents

Description

1 AIR CONDITIONING TECHNICAL FIELD The present invention relates to conditioning of air for clean room 5 applications, such as for electrical switch rooms or equipment installations. BACKGROUND It is often necessary to provide air conditioning to rooms or buildings to ensure that the amount of particulate matter is kept to a minimum or completely 10 removed. Such rooms can be electrical switch rooms or installations where dust in the air can settle on sensitive electrical equipment and cause electrical fires or electrical shorting, or even create a risk of electrical shock if the dust is electrically conductive. Environments like this can be found at or close to iron ore mines or the like. In such cases, the exterior environment can be dust laden much of the 15 time. It is therefore necessary to provide a positive pressure clean room air conditioning system that filters out particulate matter when putting clean air into a room or building whilst also maintaining positive pressure within the room or building so that dust does not enter the when someone gains access/egress to the room or building. 20 With this in mind, it is desirable of the present invention to provide an air conditioning unit with enhanced capability to maintain a clean air environment. SUMMARY OF THE INVENTION With the aforementioned in mind, an aspect of the present invention 25 provides an air conditioning unit including an air inlet, an air outlet disposed, in use, in a room or building, and an air flow path between the inlet and outlet, the air flow path incorporating at least one cyclonic air separator to remove larger particulate solids entrained in the air, at least one filter to remove smaller particulate solids entrained in the air, and at least one fan creating forced airflow 30 through the flowpath, the at least one fan outputting filtered air through the outlet into the room or building, the at least one filter and the at least one fan housed in a cabinet, the at least one filter upstream in the air flow path to the at least one 2 fan, the cabinet internally providing a clean side and a dirty side such that the at least one fan sucks air along the air flow path from the cabinet dirty side, through the at least one filter, to the cabinet clean side prior to outputting the cleaned air to the outlet. 5 The combination of cyclonic separation and physical filtering, along with multiple airflow provides enhanced positive pressure air conditioning for clean room applications. The air conditioning unit may be provided as a self contained unit with the cyclonic separator(s) either within the cabinet or more preferably mounted to the 10 exterior of the cabinet. The unit is therefore provided as a discrete module that can be delivered as a single unit, placed in situ and connected to an electrical supply and the conditioned air outlet connected to an air inlet of the room or building (when the unit is situated outside of the room or building). Maintenance on the unit, such as filter replacement, can therefore be carried out without 15 entering the room or building and otherwise risking dust entering. Multiple cyclonic separators may be employed. The cyclonic separator(s) may be specified for a required capacity to suit the capacity of the rest of the unit and demands for clean conditioned air of the room or building and required positive pressure therein. 20 The cyclonic separator(s) may remove of up to 95% of particles over 40 microns prior to the filter(s) and thereby prolonging filter life. The unit can operate with only one cyclonic separator, especially by using a suitable capacity separator. However, the unit may have a large centrifugal fan or multiple fans and multiple cyclone separators. For example: 1 0001itre per second total fan 25 capacity and 3 cyclonic separators. Multiple fans may be provided in series or in parallel in the flowpath. That is, in series, airflow is through each fan one after the other. Alternatively, with the fans in parallel, airflow is shared between the fans simultaneously. Multiple fans provides for increased airflow over a single fan, provides for 30 failure or redundancy should one fan fail or require replacement. For example, a single fan might output 150 litres of air per second airflow volume, whereas a second fan of the same capacity as the first helps to create around a total of 350 litres of air per second of airflow volume.

3 Furthermore, should one fan fail, the air conditioning unit can provide at least some air conditioning though at either a reduced capacity (less volume of air per minute) or reduced room/building pressure, or the remaining fan(s) must work at increased capacity to account for the failed/removed fan. 5 Positive pressure in the room or building aids in preventing ingress of dirt and other particulates. The air conditioning unit may be provided as a standalone or turnkey unit incorporating the cyclonic separator(s), filter(s) and fan(s) with or into a housing. Only electrical power to drive the fans and provide power to controls is required in 10 situ. This provides the ability to deliver a unitary air conditioning unit in a discrete housing and capable of providing clean room positive air pressure and air filtration deliverable as a unit requiring only an electrical supply and connection of the air inlet to the exterior from inside the room/building or connection of the outlet to the interior of the room/building from the exterior. That is, the unit could be 15 positioned within or outside of the room/building in a standalone arrangement. The arrangement of multiple fans also has cost and performance benefits over a single larger fan because smaller fans are less power hungry, are easier to start up, and are easier to replace. 20 BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows an air conditioning unit according to an embodiment of the present invention. 25 DESCRIPTION OF PREFEERED EMBODIMENTS One or more embodiments of the present invention will hereinafter be described with reference to the accompanying drawings. However, the specificity of the following description and drawings is not to be taken to limit the generality of the present invention. 30 Figure 1 shows an air conditioning unit according to an embodiment of the present invention. A flow path is created between an inlet 8 and an outlet 10. A cabinet 2 is provided that is essentially divided internally into two halves, a dirty air side 4 and a clean air side 6. The dirty air side 4 houses multiple filters 14, 4 whilst the clean air side houses two electrically driven fans 16 arranged sequentially in the airflow path i.e. one after the other. A cyclonic separator 12 is mounted to an upper portion of one part of the cabinet. In this embodiment the cyclonic separator is mounted directly above the dirty air side of the cabinet. An 5 airflow vortex is created through this separator removing heavier or larger particulate matter. The air is therefore partially filtered before passing through the multiple filters 14. These filters 14 can be filter elements preferably disposable type filters made of paper type material, such as used as truck engine air filters. Alternatively, cleanable mesh filters may be used. The multiple fans suck 10 external 'dirty' air through the cyclonic separator and filters and force the conditioned air out through the outlet 10.

Claims (5)

1. A freestanding air conditioning unit including an air inlet, an air outlet disposed, in use, in a room or building, and an air flow path between the inlet and outlet, the air flow path incorporating at least one cyclonic air separator to remove 5 larger particulate solids entrained in the air, at least one filter to remove smaller particulate solids entrained in the air, and at least one fan creating forced airflow through the flowpath, the at least one fan outputting filtered air through the outlet into the room or building, the at least one filter and the at least one fan housed in a cabinet, the at least one filter upstream in the air flow path to the at least one 10 fan, the cabinet internally providing a clean side and a dirty side such that the at least one fan sucks air along the air flow path from the cabinet dirty side, through the at least one filter, to the cabinet clean side prior to outputting the cleaned air to the outlet.

2. A unit according to claim 1, including multiple fans and the fans are 15 arranged in series such that airflow is sequentially through one fan after the other.

3. A unit according to claim 1, including multiple fans and the fans are arranged in parallel and airflow is shared between the fans simultaneously.

4. A unit according to any one of the preceding claims, including multiple cyclonic separators. 20

5. An air conditioning unit substantially as hereinbefore described with reference to the accompanying drawing. WATERMARK PATENT & TRADE MARK ATTORNEYS 25 UIP1242AUOO