WO2015034379A2

WO2015034379A2 - An air cleaner and a method of use

Info

Publication number: WO2015034379A2
Application number: PCT/NZ2014/000194
Authority: WO
Inventors: Joshua Gad CARTER; Steve Herbert CARTER
Original assignee: Forest Aire Automotive Airconditioning Ltd
Priority date: 2013-09-09
Filing date: 2014-09-09
Publication date: 2015-03-12
Also published as: WO2015034379A3; AU2014315758A1

Abstract

An air cleaning device and method of use are described. The air cleaner creates a rotating flow of air within a chamber to remove particulates and contaminants therefrom. The device can be used to provide a flow of air to pressurise a confined space.

Description

AN AIR CLEANER AND A METHOD OF USE

TECHNICAL FIELD

The present invention relates to an air cleaner and a method of use. BACKGROUND ART It is often necessary to have a supply of air for use in industrial applications. For instance, clean air is required for use in vehicle engines or the ventilation systems of buildings and vehicles. Often though, the available air contains contaminants in the form of particulate or other debris. Contamination of air sources is a particular problem for vehicles used in applications such as mining, where they are exposed to significant contaminant sources.

Furthermore, the contaminants in mines are often hazardous to human health e.g. asbestos.

Various types of air cleaners are known. The simplest of these is an air filter positioned at or towards an air intake. The filter can be a porous material such as a sponge or fine lattice material. This type of filter provides adequate results for certain applications e.g. domestic vehicles. However they cannot handle significant contaminant material as they become clogged, which reduces their effectiveness. Therefore this type of filter is not well suited for use in applications with high contaminant levels such as mine vehicles.

Complex air cleaning devices are also known. For instance, one type of device utilises centrifugal forces to create a rotating flow of air, that is divided into inner and outer orbits. Creating the rotating flow of air imparts momentum to particulate material in the air. The centrifugal forces associated with the momentum and rotational movement results in a portion of the particulate material being moved to the outer orbits of the rotating air flow. The device then directs the outer orbits containing the particulate material through a discharge port. The inner orbits of the rotating air flow, which are comparatively contaminant free, are directed through an outlet for subsequent use. This type of device is generally referred to as a cyclonic filter as the rotating flow of air resembles a cyclone. A well known manufacturer of cyclonic-type air filters is Sy-Klone Company, Inc of the United States. This company's devices all utilise a fan to draw air into a housing. The fan is an impeller-type, having a central shaft, and rotating blades extending therefrom. The blades are substantially perpendicular to the length of the shaft. However, the blades are inclined so as to create a linear flow of air into the housing e.g. rotation of the blades causes air to be drawn into the housing in a linear direction.

The fan may create some degree of rotational movement to the air flow. However that is insufficient to sufficiently stratify the air into a rotating air flow in which the particles are forced into the outer orbits of the rotating air flow. As a result, Sy-Klone's products use different features and/or configurations to generate rotating air flows which more effectively remove the contaminants.

United States Patent No. 6,338,745 to Sy-Klone Company, Inc describes an example of one of its cyclonic air filters.

The device has a housing that defines a separation chamber. An annulus is positioned at approximately the middle of the chamber's length. The annulus includes a plurality of vanes which are orientated at an angle to the longitudinal axis of the chamber. As rotating air within the housing approaches the vanes it is caused to back up / compress. This forces particulate matter within the rotating outer orbits of the rotating air flow to be ejected through a first discharge port. Air subsequently moves through the vanes and into a rear section of the housing.

The relationship between the housing diameter, annulus, and vanes are adjusted to control the size and amount of solid debris ejected from the device. Therefore the device is claimed to achieve a desired target level of clean air.

However, this device uses an axial fan, which pushes air substantially parallel to the fan's axis of rotation. This is why the device requires vane assemblies within the chamber to create a rotating flow of air. The result the strength of the rotating flow of air is quite weak and therefore significant momentum is not imparted to the particulate material in the rotating flow. The end result is that these devices do not maximise the potential for centrifugal forces to clean air.

The foregoing issues mean that in these devices air must be caused to back up/compress to achieve the necessary ejection of particles. This complicates the design and operation of these devices. However the operation of the device is limited due to the rotational forces which the fan can impart to the air flow. As a result it is necessary to have sequential chambers within the housing in which the air is rotated to remove particles from the air. The arrangement of the annulus and other parameters must be correctly adjusted to achieve target level of air purity. This is complex. Furthermore, the device is limited by the volume of air which the fan can move. That may limit the device's suitability for use in certain situation. Alternatively, a large device may be required to achieve a desired flow of clean air. Such a device would consume more power or occupy a larger space.

United States Patent No. 6,319,304 to Sy-Klone Company, Inc discloses another example of its cyclonic air filtration devices. Again, the device disclosed by this patent includes a housing having a fan rotatably mounted therein. In-use rotation of the fan draws air through an inlet and into the housing.

Again, this device uses an axial type fan, which as noted above produces a weakly rotating flow of air. Therefore, these devices are subject to the inherent limitations of the other devices discussed above.

Devices are known to provide pressurised flows of air for use in applications such as the ventilation of vehicles and buildings. One of these devices is a blower scroll having a housing and a blower wheel therein. Rotation of the blower wheel draws air in through an inlet into the housing. All of the air drawn into the housing is directed into a rotating flow of air. That rotating flow of air in its entirety exits the housing through a discharge port at substantially right angles to the direction of flow through the inlet. These arrangements do not use the blower scroll to remove particulate matter from the air. Rather, the blower scroll is simply a means to create a pressurised flow of air sufficient to meet the desired use.

Filter media may be positioned so that air flowing out of the chamber must pass through the filter media. However, these devices may have a number of problems. For instance, the filter media are required to remove all of contaminant material from the pressurised air flow. That may be a functional solution where the air does not contain significant contaminant material. However the devices are not suitable for use in all applications, especially those where there is significant contamination of the air source.

The prevailing wisdom is that blower scrolls should be used to direct all of the air drawn into a housing into a single air flow so as to create the desired pressure. They direct a lot of air into a single air stream. The contaminants are therefore forced into that single stream of air. Those skilled in the art would not therefore use the devices in other applications where a clean stream of air is to be used.

It would be an advantage to have an improved air cleaner which does not suffer from any or all of the problems of the prior art. Alternatively, it would be an advantage to have an air filter that is better adapted for use in applications where a source of air has significant levels of contaminant such as vehicles used in mining.

In addition, it is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice. All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country. Throughout this specification, the word "comprise", or variations thereof such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps. Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF THE INVENTION

According to one aspect of the present invention there is provided an air cleaner, including a housing, a primary chamber within the housing, an inlet and an outlet to the primary chamber, a discharge port, a centrifugal blower impeller ("CBI") in the primary chamber, wherein the CBI is configured such that rotation of the CBI draws air through the inlet into the primary chamber and to create a rotating flow of air within the primary chamber, and wherein the outlet to the chamber and discharge port are positioned with respect to the rotating flow of air such that a portion of air in the rotating flow of air is directed through the discharge port so as to exit the primary chamber and a portion of air in the rotating flow of air is directed through the outlet. According to another aspect of the present invention, there is provided a method of removing contaminants from air, the method using an air cleaner including a housing, a primary chamber within the housing, an inlet and an outlet to the primary chamber, a discharge port, and a centrifugal blower impeller ("CBI") in the primary chamber, the method including the steps of: (a) rotating the CBI so as to draw air through the inlet and into the chamber and to create a rotating flow of air within the chamber;

(b) directing a portion of air in the rotating flow of air through the discharge port;

(c) directing a portion of air in the rotating flow through the outlet. According to another aspect of the present invention, there is provided a vehicle including an air cleaner as substantially described above.

In embodiments, the CBI creates a rotating flow of air within the primary chamber. At least a portion of that flow of air may be directed out of the primary chamber via the outlet so that it can be used for a purpose. Throughout the present specification reference to the term "air cleaner" should be understood as meaning a device to remove at least a portion of contaminants from a flow of air so as to provide a flow of air that is comparatively cleaner that air flowing into the device.

Throughout the present specification reference may be made to the term "contaminated air". This should be understood as referring to air containing particulate matter or other debris to be removed from the air.

Throughout the present specification reference will be made to the term "comparatively clean flow of air". This should be understood as being a relative reference, meaning air at a specific point or location of the air cleaner, and which contains less contaminants than air upstream of the specific point. Most commonly, the comparatively clean flow of air will be air exiting through the outlet to the primary chamber. This air contains less contaminant material than the contaminated air entering the primary chamber through the inlet.

However, the term "comparatively clean flow of air" could also refer to air exiting from a secondary air filter which is located downstream from the primary chamber. The comparatively clean flow of air can be used in any of various applications. For instance, the comparatively clean flow of air can be directed into an air intake of an engine, or used in a vehicle's ventilation or air conditioning system. It is also envisaged that the comparatively clean flow of air can be used to pressurise a space such as a vehicle's cabin. The inventors have found that the invention may be particularly well suited to use in mining applications. This is due to those environments having significantly contaminated air, with contaminants which are hazardous to human health / well being. This is because the inventions are able to remove a significant amount of the contaminants commonly encountered in mining applications. Accordingly, the foregoing should not be seen as limiting on the scope of the invention and its potential applications.

Throughout the present specification reference to the term "chamber" should be understood as meaning a cavity in the air cleaner.

An air cleaner according to the invention may have multiple chambers. For instance the air cleaner may include a primary chamber in which the CBI is positioned and/or mounted. Additional chambers such as a secondary chamber and potentially a tertiary chamber may also be included downstream of the primary chamber.

In-use, the chamber provides a defined space for a flow of air. The affect of the chamber on the flow of air will depend on the components of the air cleaner within the chamber. For instance, the primary chamber may help to create a rotating flow of air by rotation of the CBI. The primary chamber is therefore important to ensuring that the rotating flow of air can be efficiently created, and to maximise the momentum forces imparted to contaminant material in the rotating flow of air.

Alternatively, the secondary chamber may help to direct a flow of air away from the primary chamber. However, the foregoing should not be seen as limiting on the scope of the invention. It is also envisaged that the air cleaner could include only the primary chamber, or more than four chambers.

In an embodiment, the primary chamber has a spiral cross-sectional area when viewed along its longitudinal axis. This shape is also known as a scroll or a volute.

The inventors have identified that this preferred shape for the cross sectional area of the chamber provides a number of advantages. For instance, the shape may help to direct outer orbits of a rotating flow of air created in the chamber through the discharge port. This in-turn helps to prevent the contaminant material being inadvertently directed through the outlet. It therefore may help to improve the efficiency of operation of the air cleaner.

However, the foregoing should not be seen as limiting on the scope of the present invention and other shapes for the chamber are envisaged.

Throughout the present specification reference to the term "inlet" should be understood as meaning an opening through which contaminated air can flow to enter the primary chamber. Throughout the present specification reference to the term "outlet" should be understood as meaning an opening in the primary chamber through which a comparatively clean flow of air can exit the primary chamber.

The outlet may include one or more connectors configured to engage with complementary connectors on an end use apparatus. For instance, a hose may be connected to the outlet to direct air exiting through the outlet to an engine or vehicle ventilation system.

Alternatively, the outlet may connect the primary chamber to a secondary air cleaner (as are discussed in more detail below). Accordingly, the foregoing should not be seen as limiting on the scope of the present invention.

Throughout the present specification, reference to the term "discharge port" should be understood as meaning an aperture in the housing through which air in the rotating flow of air can be discharged. In embodiments the discharge port may be connected to a pipe directing air flowing through the discharge port away from the air cleaner.

However, the foregoing should not be seen as limiting on the scope of the present invention.

In an exemplary embodiment, the discharge port is in line with the tail end of the spiral of the primary chamber.

In an exemplary embodiment, the outlet is offset from the discharge port, and distal to the inlet. Therefore in use, air flowing through the inlet is caused to form a rotating flow of air in the primary chamber. That rotating flow of air exits the primary chamber via the discharge port. However, a portion of the rotating flow of air is able to be directed through the outlet. The inventors have found that creating a sufficiently strong rotating flow of air within the primary chamber imparts significant momentum to particulates and contaminants in the air. Therefore, those exit the primary chamber via the discharge towards the inlet. However, the remaining air within the rotating flow can be directed through the outlet as it is comparatively clean.

Surprisingly, the arrangement described herein provides sufficient momentum to particulate and contaminant material that air flowing via the outlet is comparatively clean. This may remove the need to create a second rotating flow of air to sufficiently clean the air. This is unusual and prior art devices create sequential rotating flows of air for the purpose of removing contaminants therefrom.

As a result of the foregoing, the invention may be simpler to design, manufacture and/or maintain. It may also provide a more efficient air cleaning.

Throughout the present specification reference to the term "centrifugal blower impeller" should be understood as meaning a device configured to create a flow of air, and which discharges the air in a direction perpendicular to the axis of the device's rotation.

In an embodiment, the "CBI" is a blower scroll. In this embodiment, the blower scroll is formed from the primary chamber which provides the "scroll" component. A blower wheel is mounted within the primary chamber. However, the foregoing should not be seen as limiting on the scope of the present invention. Alternatives for the CBI are envisaged including paddle fans which have blades shaped to direct a substantial portion of air in a direction substantially perpendicular to the fans axis of rotation. The blower wheel is configured to create a rotating flow of air that includes a plurality of orbits comprising inner orbits being those orbits closest to the centre of the cavity, and outer orbits being those which are closest to the outside wall of the primary chamber.

In an embodiment, the blower wheel includes a frame comprising a pair of spaced apart rings. The rings are held in a fixed relationship with respect to each other by frame members and/or the vanes.

The blower wheel includes a plurality of vanes. The vanes are positioned around the circumference of the blower scroll and orientated so as to extend along the longitudinal axis of the blower wheel.

Adjacent vanes around the circumference of the blower wheel are separated by apertures which extend substantially between the pair of rings.

In-use, rotation of the blower wheel by a motor draws air through the inlet and into the chamber. The air subsequently moves through one of the rings and into an internal cavity of the blower wheel defined by the vanes.

Continued rotation of the blower wheel forces air out through the apertures between radially adjacent vanes. The orientation of the vanes forces the air to separate into a rotating flow of air within the chamber.

However, the foregoing should not be seen as limiting on the scope of the present invention. In an embodiment, the invention may include a secondary air cleaner.

The secondary air cleaner removes at least a portion of contaminant material which may be present in the comparatively clean flow of air exiting the primary chamber through the outlet. In an embodiment, the secondary air cleaner is a non-centrifugal type air cleaner. That is, the secondary air cleaner does not utilise creation of a rotating flow of air so as to remove particulate material from a portion of the rotating flow.

In these embodiments, the secondary air cleaner includes one or more filter media through which the comparatively clean flow of air is directed. The filter media can therefore remove contaminant material from the flow of air.

As noted above, the air cleaner may include a secondary chamber and potentially a tertiary chamber. Throughout the present specification reference to the term "secondary chamber" should be understood as referring to a cavity downstream of the primary chamber. Similarly, the term "tertiary chamber" should be understood as referring to a cavity downstream of the secondary chamber.

The secondary and tertiary chambers may be defined by partitions within the housing. Alternatively, the secondary and/or tertiary chambers may be provided in separate housings which are connected or connectable to the primary chamber.

In an embodiment the second and/or tertiary chambers may each include a secondary air filter, such as a filter media.

However, the foregoing should not be seen as limiting on the scope of the present invention. Throughout the present specification reference to the term "filter media" should be understood as meaning a body through which air can be passed to remove contaminants from the air.

It should be understood that the filter media are stationary. Removal of contaminant material from air is achieved by interaction of the filter material with the air as the air passes through the filter media. Preferably the secondary chamber contains a MERV filter while the tertiary chamber contains a HEPA filter.

The terms MERV and HEPA filter are terms of the art and are as should be understood by one skilled in the art. The inventor has surprisingly found that the interaction of the CBI with the MERV and/or HEPA filters provides a number of synergistic advantages. For instance, the blower scroll is able to efficiently remove a significant proportion of contaminant material from the flow of air drawn into the air cleaner. That means that the MERV and subsequently HEPA filters are exposed to lower levels of contaminant material. As a result, the function of the filter media may be improved.

Furthermore, the life span of the filter media may be improved. That is beneficial as it reduces operational costs for the air cleaner by decreasing the use of components associated with the air cleaner's operation, and increases the time between servicing.

The inventors have also found that use of a blower scroll as a CBI is surprisingly able to generate sufficient flows of comparatively clean air to meet the demands of a desired end use. This is unusual given that industry wisdom is that blower scrolls direct the entirety of a flow of air out into a rotating flow, which does not provide any cleaning action for that flow of air.

In contrast, the invention takes a portion of a rotating flow of air and directs that away from the rotating flow. That portion of the air flow directed through the outlet is comparatively cleaner than the remainder of the air within the rotating flow which is directed thorough the discharge port. As a result, the use of the blower scroll as the CBI provides a comparatively clean flow of air that is suitable for an end use.

According to a second aspect of the present invention, there is provided an air cleaner, including a housing, a primary chamber within the housing, an inlet to the primary chamber and an outlet to the primary chamber, a primary flow generator configured to create a flow of air through the inlet and into the primary chamber and create a rotating flow of air in the primary chamber, a secondary chamber connected to the outlet to the primary chamber, a filter media, a secondary flow generator that is configured to in use direct air through the outlet to the primary chamber.

In exemplary embodiments, the second aspect of the present invention may be incorporated into the air cleaner as substantially described above. However, this should not be seen as limiting on the scope of the present invention. It is also envisaged that the second aspect could form the basis of a stand alone air cleaner which does not utilise a CBI within the primary chamber of the housing.

Throughout the present specification "flow generator" should be understood as meaning a component to create a flow of air.

In an embodiment, the primary flow generator and primary chamber may be the CBI such as a blower scroll as is described above. This is beneficial where the second aspect of the present invention is incorporated into the air cleaner described herein.

However, it is also envisaged that the primary flow generator may be any device configured to create a flow of air e.g. a fan and motor arrangement. Therefore the foregoing should not be seen as limiting on the scope of the present invention.

In an embodiment, the secondary flow generator may also be a blower scroll and blower wheel. However, in this embodiment, the secondary flow generator is positioned and configured such that a rotating flow of air created by the blower scroll is directed to an end use. This is in contrast to the use of a blower scroll within the primary chamber, where the rotating flow of air is directed away from the air cleaner device through the discharge port.

The inventors have surprisingly found that the use of a secondary flow generator downstream of the filter media helps to achieve a desired pressure of air flow out of the air cleaner. This is useful as filter media may limit the flow of air exiting the primary chamber. Therefore, the secondary flow generator helps to ensure that there is a sufficient flow of air to meet the requirements of the end-use. This may be particularly beneficial where a minimum flow of air is required for that end-use e.g. the flow of air out of the air cleaner is utilised to pressurise a vehicle cabin in applications such as mining vehicles. In an embodiment, the secondary flow generator is configured to rotate at variable speeds to provide a desired air flow out of the air cleaner.

However, the foregoing should not be seen as limiting on the scope of the present invention. It is also envisaged that the second flow generator may rotate at a fixed rate e.g. may not be configured to rotate at different rates. In these embodiments, the second flow generator may be connected to a control system. In- use, the control system receives information from sensors on parameters corresponding to the end-use. The control system is configured to determine a rate of rotation of the second flow generator necessary to achieve the desired air flow rate.

Therefore, the control system determines whether the second flow generator needs to rotate faster or slower to achieve the desired air flow rate. The control system therefore can communicate with the second flow generator to adjust its rate of rotation to achieve the desired air flow rate.

BRIEF DESCRIPTION OF DRAWINGS

Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which: is an exploded view of components of an air filter according to the present invention; is a side cross-sectional schematic showing components of an air filter according to the present invention and air flow direction there through; is a plan view of an air cleaner according to the present invention; is a view through line B-B shown in Figure 3A; is a view through line A-A shown in Figure 3A; is a close up exploded view showing a blower scroll, primary housing, motor, and motor mounting according to the present invention; is a side perspective view of a primary housing according to the present invention; is a bottom perspective view of a housing according to the present invention; is an end-on cross-sectional view of a primary housing according to the present invention; is an end-on view showing the cross sectional shape of the inner wall of the primary housing of Figure 5C; is a close up exploded view of a supplementary air flow generator, and mounting therefore; is a schematic showing communication and control of the present invention; is a schematic showing connection of an air cleaner according to the present invention to a vehicle; is a first view of a blower wheel according to an embodiment of the invention; is a second view of the blower wheel of Figure 9A. Figure 9C is a third view of the blower wheel of Figures 9A and 9B;

Figure 10 is a view of a vehicle including an air cleaner according to an embodiment of the invention.

BEST MODES FOR CARRYING OUT THE INVENTION Referring first to Figures 1 and 2, there is provided an air cleaner (1).

The air cleaner (1) includes a frame (2) to which the components of the air cleaner (1) may be secured.

The frame (2) includes a base (3). The base (3) provides a rigid support that facilitates the air cleaner (1) being secured in a desired position. The base (3) therefore facilitates connecting the air cleaner (1) to other devices such as vehicles or buildings (neither shown in the Figures). A housing indicated generally as (4) is secured to the frame (2). The housing (4) is best seen in Figure 4.

The housing (4) includes a first end plate (5A) and a second end plate (5B). The end plates (5A, 5B) are secured to a side wall (6). Each of the end plates (5A, 5B) includes an aperture (6A, 6B) respectively. The end walls (5A, 5B) and side wall (6) define a primary chamber (7).

The aperture (6A) provides an inlet to the primary chamber (7), while the outlet (6B) provides an outlet to the primary chamber (7).

The side wall (6) includes an inner surface having a generally spiral cross-sectional shape.

The inner surface has a head (69) and a tail (70). The tail (70) forms a discharge port (71) and is configured to be connected to a conduit (not shown in Figure 1) that directs air flowing through the discharge port (71) away from the air cleaner (1).

A blower wheel, indicated generally by (9) is positioned within the primary chamber (7). The blower wheel (9) is shown in more detail in Figures 9A and 9B. The blower wheel (9) includes a first ring (10A) and a second ring (10B). A plurality of vanes (1 1) are secured between the first and second rings (10A, 10B). A cap (10C) is secured to the ring (10B). There are a plurality of apertures (10D) defined by gaps between the cap (10C) and the vanes (11). The apertures (10D) provide a path through which air can flow when the air cleaner (1) is in use.

The blower wheel (9) is rotatably mounted inside the primary chamber (7) so that the cap (10C) and therefore the apertures (10D) at or towards outlet (6B). The vanes ( 1) hold the first and second rings (10A, 10B) in a fixed, and spaced apart position with respect to each other.

The vanes (11) are spaced apart around the circumference of the rings (10A, 10B). In addition, the vanes (11 ) are orientated such that their length extends along the length of the cavity (7).

The cap (10C) also provides clearance between the inlet (6A) and the outlet (6B). This may assist in ensuring that a significant portion of particulates and contaminants in air flowing in the primary chamber (7) are directed out of the discharge port. For instance, this may be due to the cap providing improved performance for the blower scroll arrangement. Alternatively, the cap may assist in ensuring that air containing particulate and contaminants is directed through the discharge port at or towards an end of the primary chamber (7) nearest the inlet. That means that a supply of comparatively clean air may be available to be directed through the outlet.

Radially adjacent vanes (11) are separated from each other by apertures (12). The apertures (12) are orientated to extend along the length of the primary chamber (7). The orientation of the vanes (1 1) may assist in ensuring that air containing particulate and contaminants is directed through the discharge port at or towards an end of the primary chamber (7) nearest the inlet. The rings (10A, 10B) and vanes (11) define a blower wheel cavity (13).

The blower wheel (9) and the side wall (6) provide generally a blower scroll arrangement. The blower wheel (9) is a single entry blower wheel as should be understood by one skilled in the art. This means that rotation of the blower wheel (9) draws air into the blower scroll cavity (13) via only an aperture defined by ring (10A). A motor (14) is operationally coupled to the blower wheel (9) by axle (15). In-use the motor (14) rotates axle (15). Rotation of axle (15) is transferred to blower wheel (9). A motor mounting plate (16) is attached to second end wall (5B) of the primary housing. This is achieved using bolts ( 7) which extend through apertures (18) in the mounting plate (16) and into threaded apertures (19) in end wall (5B).

The motor (14) is secured to the mounting plate (16) using mounting bolts integral to the motor (14). One of the mounting bolts is shown as (20) in Figure 4.

The mounting bolt (20) extends through corresponding apertures (not shown) in motor mounting plate ( 6). The motor mounting bolts (20) are engaged by complementary threaded bolts (21).

The motor mounting piate (16) includes air flow apertures (22). In use, rotation of the motor (14) causes blower wheel (9) to rotate within the primary chamber (7). This draws air through aperture (6A) and into the primary chamber (7). The air inside the primary chamber (7) is forced through the apertures (10D) to create a flow of rotating air is created in the primary chamber (7). The direction of rotation is about (around) an axis defined by the axle (15). The majority of air in the rotating air flow is directed out of the primary chamber (7) through the discharge port (71). However, some air can flow out of the outlet (6B).

The orientation of outlet (6B) with respect to the rotating flow of air in the primary chamber (7) is such that the air leaving the primary chamber (7) by the outlet (6B) is not rotating. Rather, the air is travelling in at least a substantially linear or turbulent path as it leaves the primary chamber (7). The outlet (6B) is also positioned distal to the inlet (6A), such as at the extreme ends of the primary chamber to each other. This may assist in ensuring that air flowing through the outlet (6B) may contain fewer particulates or contaminants.

The air cleaner (1) of Figures 1 - 8 therefore comprises a single chamber within which the blower wheel (9) rotates. The arrangement of the blower wheel (9) and primary chamber (7) may assist in simplifying its operation in comparison to the prior art cyclonic air filters. In addition, physical devices are not required which split a rotating flow of air into inner and outer orbits.

Furthermore, there may be no requirement to provide a two stage, sequential air filter, where both stages create rotating flows of air. A secondary housing (23) is secured to the frame (2). The secondary housing (23) includes a first end wall (24A), a second end wall (24B), and a side wall (25), which define a secondary chamber, indicated by (27).

The first end wall (24A) includes an aperture (26A) that provides an inlet into the secondary chamber (27). End wall (24B) includes an outlet (not shown) through which comparatively clean air can flow so as to exit the secondary chamber (27).

A filter media (28) in the form of a MERV filter as should be known to one skilled in the art is positioned in the secondary chamber (27) towards the aperture (26A). The MERV filter (28) is orientated so as to be transverse to a linear flow of air travelling through the secondary chamber (27). In addition the MERV filter (28) and secondary chamber have dimensions so that air must flow through the MERV filter to pass from inlet (6A) to the outlet of secondary chamber (not shown).

The air cleaner (1) includes a connecting conduit (29). The connecting conduit (29) connects the outlet in end wall (24B) to an inlet (not shown) in a tertiary chamber that is indicated as (30). The tertiary chamber (30) is defined by walls (not shown in Figure 1) that are secured to the frame (2).

A filter media (31) is secured inside the tertiary chamber (30). The filter media (31) is a HEPA filter as should be known to one skilled in the art. The HEPA filter (31) is positioned so as to be transverse to a linear flow of air moving through the tertiary chamber (30). The air cleaner includes a pressure sensor (74) adapted to determine pressure differences on distal sides of the filter media (31). In the embodiment shown in the Figures, the sensor (74) is a pair of pressure switches on distal sides of the filter media (31). If the sensor (74) does not detect a pressure difference then it sends a signal to a control system (41). Determining the pressure difference across the filter media (31) is useful as that provides an indication as the integrity of the filter media. For instance, if there is no pressure difference then the filter media (31) can be assumed to have ruptured, providing an open path through which air can flow. That means that the filter media (31) is not ensuring that air exiting the air cleaner (1) is at a desired level of cleanliness.

In contrast, if there is a pressure difference across the filter media (31) it can be assumed that the filter media (31) is integral. Therefore, air must pass through the filter media (31) which means that particulate material in the air can be removed.

A secondary air flow generator (32) is secured to frame (2). The secondary air flow generator (32) is positioned downstream of the HEPA filter (31). In addition, the secondary air flow generator (32) is adjacent to an aperture (33) in the frame.

The secondary air flow generator (32) is shown in more detail in Figure 6. The secondary air flow generator (32) includes a blower wheel (33) secured within a housing (34). The blower wheel (33) is a two inlet / intake blower wheel as should be known to one skilled in the art.

A motor (not shown in the Figures) is operatively connected to blower wheel (33) by an axle (not shown in the Figures). In-use rotation of the axle by the motor (neither shown) causes the blower wheel (33) to rotate in the housing (34).

The housing (34) has two air intakes, the location of which are indicated by (35) in the Figures.

The housing (34) includes an outlet (36). The outlet (36) is orientated at substantially right angles to the air intakes (35). The blower scroll (33) operates as a pressuriser so as to take air from the cavity (30) and to create a pressurised (high volume) flow of air out through the aperture (36).

The housing (34) is secured to a mounting plate (37) by screws (39) that extend through complementary apertures in the mounting plate (37) and housing (36).

An outlet plate (38) is secured to mounting plate (37) by screws (40) that extend through complementary apertures in the mounting plate (37) and outlet plate (38).

Both of the outlet plate (38) and mounting plate (37) have apertures (41) and (42) respectively. The apertures (41 , 42) align with aperture (36) in the housing (34). Therefore, the apertures (36, 41 , 42) define an air flow path from the housing (34) and out of aperture (42). This enables the rotating flow of air generated by the blower wheel (33) to be directed out of the aperture (42) and thereby to exit the air cleaner (1).

The secondary air flow generator (32) does not provide an air filtering or cleaning function. Rather, the secondary flow generator (32) creates suction to draw air through outlet (6B) and into the secondary housing (23), and eventually force the air to exit the air cleaner (1).

The aperture (41) is shaped and/or configured to be connected to a conduit (not shown in the Figures). The conduit can take air from the air cleaner (1) to an end use such as a vehicle's engine or air conditioning system. Control System

An air cleaner (1) can be secured to a vehicle (100) as is shown in Figure 10.

Referring now to Figures 2 and 7.

A control system (43) having a computer programming apparatus (44) is connected to the air cleaner (1). The computer programming apparatus (44) is in communication with at least one, and preferably all of, the components of the air cleaner (1). The communication may be facilitated by wireless technology.

In addition, the control system (43) may be able to wirelessly communicate with external computer processes to facilitate control and monitoring of the air cleaner (1) remotely, such as by service technicians. The computer programming apparatus (44) is configured to communicate with a display (45). The display (45) may be positioned inside of the vehicle's cabin (60). The display (45) therefore provides information on operation of the air cleaner (1) to the vehicle operator.

A sensor (49) may be positioned in the vehicle's cabin (60). The sensor (49) monitors the air pressure within the vehicle cabin (60). Readings from the sensor (49) are transmitted to the computer programming apparatus (44). The computer programming apparatus (44) monitors the information from the sensor (49) to determine whether air pressure in the cabin drops below or exceeds predetermined limits.

The computer programming apparatus (44) is also connected to light (69). When the air cleaner (1) is operating the light (69) flashes. This provides a visible signal that the air cleaner (1) is functioning. However, if certain parameters of the operation of air cleaner (1) fall below minimum predetermined standards, for instance, if the air cleaner fails, or air pressure in cabin (60) drops below the minimum, the CPA (44) disengages the light (69).

Connection to Vehicle

Referring now to Figure 2 showing a schematic of how the air cleaner (1) may be connected to a vehicle (100).

The vehicle (100) includes a cabin (60). The vehicle's air conditioning system includes a first intake (61) and a conduit (62) secured thereto. The conduit (62) is configured to be secured to an aperture (63) in a cover plate (64). The cover plate (64) is secured to end plate (5a).

The cover plate (64) has a second aperture (65). The second aperture (65) is configured to be connected to a conduit (not shown in the Figures). The conduit (not shown) is positioned so as to draw air from around the vehicle (100) through the aperture (65) and direct that through inlet (6A).

A conduit (66) is connected to aperture (42). The conduit (66) forms part of the vehicle's ventilation system. The conduit (66) is also attached to an aperture (67) in the vehicle's ventilation system so as to direct air flowing through the aperture (42) into the cabin (60). In- Use

Referring now to Figure 2, operation of the air cleaner (1) will now be described.

Parameters of the air to be produced by the air cleaner (1) are entered into the computer programming apparatus (44). The computer programming apparatus (44) determines an operational programme at which the blower wheel (9) and secondary air flow generator (32) are to operate. This may include determining:

1. Rotation rates for the blower wheels (9, 33);

2. Air flow rate out through aperture (42) required.

The computer programming apparatus (44) sends signals to the motor (not shown) so as to rotate at a rate required to achieve a desired air flow. Rotation of the motors (not shown) causes a corresponding rotation of the blower wheels (9, 33).

Rotation of blower wheel (9) causes air from outside of the air cleaner (1) to flow through inlet (6A) into primary chamber (7) in the direction shown by arrows (46). Air flowing into primary chamber (7) enters blower wheel cavity (13). Continued rotation of the blower wheel (9) causes air within the blower wheel cavity (13) to be directed through the apertures (12) between vanes (11). This creates a rotating flow of air within the primary chamber (7). A portion of air in the rotating flow of air exits the primary chamber through discharge port (71) in the direction shown by arrows (47) in Figure 2.

The inventor has found that operation of the blower wheel (9) is able to impart sufficient momentum to particles within the rotating flow of air that the majority of the particles, including all heavier particles, exit the primary chamber via the discharge port (71) towards first end wall (5a) rather than towards second end wall (5B). Therefore, air forming part of the rotating air flow in the region of the second end plate (5B) is comparatively cleaner than air towards first end plate (5A). A portion of air within the primary chamber (7) towards the second end plate (5B) is directed through the outlet (6C) in the direction of arrows (48). The secondary air flow generator (32) creates suction to direct air from the primary chamber (7) through the outlet (6C) and enters the secondary chamber (27) via inlet (26A). The direction of flow of the air through the secondary apertures (22), through inlet (26A) and inside secondary chamber (27) is linear. That is, the flow of air does not have any substantial rotational motion. The air flowing through secondary chamber (27) passes through the MERV filter (28) in the direction shown by arrows (50). The air exiting the secondary outlet (24) flows through conduit (29) and into tertiary chamber (30) in the direction shown by arrows (51).

Air flowing through chamber (13) passes through HEPA filter (31) in the direction shown by arrows (52). The secondary air flow generator (32) draws air passing through the HEPA filter (31) and in through the apertures (35) in the direction shown by arrows (53). Rotation of the blower wheel (33) directs air out through aperture (42) in the direction shown by arrows (54).

If the pressure in the vehicle's cabin (60) drops below a minimum pressure then the computer programming apparatus (44) sends a signal to secondary flow generator (32) to increase its speed of rotation. This increases the flow of air through the filter media (28, 31). It may also increase the flow of air through the inlet (6A) and into the primary chamber (7).

The air flows through the secondary flow generator (32), and exits the air cleaner (1) via outlet (36). The increased flow of air is therefore able to increase the pressure in the vehicle's cabin (60). In addition, the computer programming apparatus (44) can send a signal to display (45) to display a warning signal that the pressure in the vehicle's cabin (60) has dropped below the minimum air pressure. Therefore the vehicle operator can take appropriate remedial action.

If the pressure in the vehicle's cab (60) exceeds a maximum pressure then the computer programming apparatus (44) sends a signal to secondary flow generator (32) to adjust its speed of rotation to reduce or minimise the air flowing into the vehicle's cab. For instance the secondary flow generator (32) may stop rotating completely or decrease its speed of rotation. This reduces or stops the flow of air through the filter media (28, 31). In addition, the rate of flow of air through secondary flow generator (32) and out of outlet (36) is decreased or stopped. Therefore, the air pressure in the vehicle's cabin (60) is not increased by the flow of air out of the air cleaner (1).

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims.

Claims

WHAT WE CLAIM IS:

1. An air cleaner, including a housing, a primary chamber within the housing, an inlet and an outlet to the primary chamber, a discharge port, a centrifugal blower impeller ("CBI") in the primary chamber, wherein the air cleaner is configured such that operation of the CBI draws air through the inlet into the primary chamber and creates a rotating flow of air within the primary chamber, and wherein the outlet to the chamber and discharge port are positioned with respect to the rotating flow of air such that outer orbits of the rotating flow of air are directed through the discharge port so as to exit the primary chamber and inner orbits of the rotating flow of air are directed through the outlet.

2. The air cleaner as claimed in claim 1 , wherein at least a portion of the primary chamber has a spiral cross-sectional area when viewed along its longitudinal axis

3. The air cleaner as claimed in claim either one of claims 1 or 2, wherein the outlet is configured to be connected to an end-use.

4. The air cleaner as claimed in either one of claims 1 or 2, wherein the outlet is connected to a secondary air cleaner.

5. The air cleaner as claimed in any one of claims 1 to 4, wherein the discharge port is connected to a pipe configured to direct air flowing out of the primary chamber through the discharge port away from the air cleaner.

6. The air cleaner as claimed in claim 5, wherein the discharge port is in line with an end of a tail end of the spiral shaped section of the primary cavity.

7. The air cleaner as claimed in any one of claims 1 to 6, wherein the CBI is a blower scroll.

8. The air cleaner as claimed in claim 7, wherein the blower scroll comprises the primary chamber within the housing and a blower wheel within the primary chamber.

9. The air cleaner as claimed in claim 8, wherein the blower wheel comprises a frame and a plurality of vanes secured to the frame.

10. The air cleaner as claimed in either one of claims 8 or 9 wherein the blower wheel is a single entry blower wheel.

11. The air cleaner as claimed in any one of claims 1 to 10, including a secondary air

cleaner.

12. The air cleaner as claimed in claim 11 , wherein the secondary air cleaner is a non- centrifugal type air cleaner.

13. The air cleaner as claimed in claim 12, wherein the secondary air cleaner is one or more filter media.

14. The air cleaner as claimed in either one of claims 12 or 13, wherein the secondary air filter includes a first filter media and a second filter media arranged sequentially with each other.

15. The air cleaner as claimed in claim 14, wherein the first filter media is a HEPA filter.

16. The air cleaner as claimed in either one of claims 14 or 15, wherein the second filter media is a MERV filter.

17. The air cleaner as claimed in any one of claims 1 to 15, including a frame that

comprises a base that facilitates the air cleaner being secured in position.

18. The air cleaner as claimed in either one of claims 1 to 17, including a secondary CBI downstream of the outlet.

19. The air cleaner as claimed in claim 18, wherein the secondary CBI is a double entry blower wheel.

20 The air cleaner as claimed in either one of claims 18 or 19 wherein the secondary CBI is positioned downstream of at least one secondary filter media.

21. The air cleaner as claimed in any one of claims 1 to 20, including a control system

comprising a computer programming apparatus in communication with at least one component of the air cleaner.

22. The air cleaner as claimed in claim 21 , wherein the control system includes a display.

23. The air cleaner as claimed in any one of claims 1 to 22, including at least one sensor to monitor air pressure within a cabin of a vehicle with which the air cleaner is used.

24. The air cleaner as claimed in any one of claims 21 to 22, or claim 23 when dependent on claims 21 or 22, wherein the computer programming apparatus is connected to a light and configured to cause the light to flash when the air cleaner is operating.

25. The air cleaner as claimed in claim 24, wherein the computer programming apparatus is configured to disengage the light when certain parameters fall below a predetermined standard.

26. The air cleaner as claimed in claim 25, wherein the parameters are air cleaner function or air pressure in a cabin of a vehicle with which the air cleaner is used.

27. The air cleaner as claimed in any one of claims 22 to 26, wherein the computer

programming apparatus is configured to display a warning signal on the display if the sensor determines that air pressure in a cabin of a vehicle with which the air cleaner is used drops below a predetermined minimum.

28. The air cleaner as claimed in any one of claims 21 to 27, wherein the control system is