WO2023037091A1

WO2023037091A1 - An extraction fan system and methods thereof

Info

Publication number: WO2023037091A1
Application number: PCT/GB2022/052123
Authority: WO
Inventors: Timothy CHATTELL
Original assignee: RVT Group Limited
Priority date: 2021-09-09
Filing date: 2022-08-15
Publication date: 2023-03-16

Abstract

An extraction fan system comprising: an air duct defining an air flow path, an air filter disposed in the air flow path, a fan for driving air along the airflow path through the filter, and an airflow monitor having a pressure sensor configured to measure a differential pressure within the air duct, and a controller connected to the pressure sensor and configured to transmit a signal indicative of a status of the filter via a network connection to a remote device for monitoring the status of the filter in real time.

Description

AN EXTRACTION FAN SYSTEM AND METHODS THEREOF

[0001] This invention relates to an extraction fan system and methods thereof.

BACKGROUND

[0002] Fan extraction systems typically use forced air to provide good ventilation within a space. It is important for such systems to be well maintained and for any blockages or faulty fans to be detected and serviced as soon as possible, as extraction systems may be used in sites where good ventilation is critical.

[0003] However, existing fan extraction systems require an operator to manually inspect fans at least once per day in order to determine the status of the fans. This is inconvenient and inefficient, as the operator may have a large number of fans to inspect in a large extraction system, such as those used to ventilate buildings.

[0004] The present invention seeks to address at least some of these issues.

BRIEF SUMMARY OF THE DISCLOSURE

[0005] Viewed from a first aspect, the present disclosure provides an extraction fan system comprising: an air duct defining an air flow path, an air filter disposed in the air flow path, a fan for driving air along the airflow path through the filter, and an airflow monitor having a pressure sensor configured to measure a differential pressure within the air duct, and a controller connected to the pressure sensor and configured to transmit a signal indicative of a status of the filter via a network connection to a remote device for monitoring the status of the filter in real time.

[0006] Thus, the present disclosure provides a device which allows for remote monitoring of air filters by operators in real time without having to physically access the filter or the location of the extraction fan system to assess the status of the filter.

[0007] The air filter may be a dust filter. The controller may be configured to calculate an airflow speed within the air duct based on the measured differential pressure data. The controller may be configured to output an alert to the remote device when the airflow speed falls below a pre-determined threshold.

[0008] The controller may be configured to determine the status of the filter based on the measured differential pressure data. The controller may be configured to transmit the status of the filter to the remote device.

[0009] The controller may be configured to output an alert to the remote device if the measured differential pressure data is outside a pre-determined range. [0010] The extraction fan system may be configured as a dust extraction unit. The dust extraction unit may be portable, for example comprising one or more wheels and/or skids or other ground engaging elements for moving the unit across a surface.

[0011] The fan may be arranged downstream of the filter. The fan may be configured to apply a suction force to drive air through the filter. This is in contrast to driving air by blowing air through the filter using a positive pressure. When the fan is positioned downstream of the filter, this may be considered to be on the “clean” side of the filter.

[0012] There is also provided a method of monitoring a status of a filter disposed in an air flow path defined by an air duct of an extraction fan system, the method comprising: measuring differential pressure data within an air duct of a fan extraction system, transmitting a signal indicative of a status of a filter within the air duct based on the measured differential pressure data via a network connection to a remote device for monitoring the status of the filter in real time, and determining the status of the filter based on the transmitted signal.

[0013] The method may include replacing the filter with a replacement filter when the status of the filter deviates from a pre-determined threshold.

[0014] The method may comprise calculating an airflow speed within the air duct based on the received pressure differential data. The method may comprise comparing the calculated airflow speed to a pre-determined threshold airflow speed. The method may comprise outputting an alert to the remote device if the air flow speed is different to, for example lower than, a pre-determined airflow speed. The alert may be transmitted by a networked connection, such as a mobile telecommunications network. This allows the alert to be transmitted as a short message service (SMS) message or an email.

[0015] The method may comprise outputting the status of the filter in response to an airflow monitor of the fan extraction system receiving a user input.

[0016] The method may comprise determining the status of the filter based on the measured differential pressure data by an airflow monitor of the fan extraction system.

[0017] There is also optionally provided an airflow monitor for use with a ducted fan, the airflow monitor comprising: a pressure sensor configured to measure a differential pressure within an air duct, and a controller connected to the pressure sensor and configured to transmit the measured differential pressure via a network connection to a remote device for monitoring of the air duct by a remote device in real time.

[0018] Thus, the present disclosure provides a device which allows for remote monitoring of air ducts by operators in real time without having to physically access the location of the fan to assess the status of a fan within an extraction system. [0019] The network connection may be a low power wide area network connection. The network connection may be a narrowband Internet of Things (loT) connection.

[0020] The pressure sensor may comprise a high pressure sensor and a low pressure sensor.

[0021] The airflow monitor may comprise a high pressure inlet port arranged to provide a fluid communication channel between the high pressure sensor and the air duct. The airflow monitor may comprise a low pressure inlet port arranged to provide a fluid communication channel between the low pressure sensor and the air duct.

[0022] The pressure sensor may have a measurement range of 1250 Pa.

[0023] The controller may be configured to sample the differential pressure at a predetermined rate. The pre-determined rate may be configurable by a user. The predetermined rate may be configurable by the remote device.

[0024] The controller may be configured to output an alert if the measured differential pressure is outside a pre-determined threshold differential pressure. The controller may be configured to output an alert if the measured differential pressure is above a pre-determined threshold differential pressure. The controller may be configured to output an alert if the measured differential pressure is below a pre-determined threshold differential pressure.

[0025] The controller may be configured to calculate an airflow speed based on the measured differential pressure data.

[0026] The airflow monitor may comprise a housing. The housing may have no local user interface for monitoring the airflow in the air duct on the airflow monitor.

[0027] Viewed from a further independent aspect, there is provided an extraction fan system comprising an airflow monitor according to any of the appended claims.

[0028] Viewed from a further independent aspect, there is provided a method of monitoring airflow within an air duct. The method comprises receiving differential pressure data measured within an air duct via a low power wide area network, calculating an airflow speed within the air duct based on the received differential pressure data, and outputting the calculated airflow speed to a remote device such that an operator of the remote device can monitor the airflow speed in the air duct in real time.

[0029] The method may comprise comparing the calculated airflow speed to a predetermined threshold airflow speed. The method may comprise outputting an alert to the remote device if the air flow speed is different to the pre-determined airflow speed. [0030] The method may comprise outputting a status of the air duct in response to a user input. The method may comprise outputting a pressure drop based on the measured differential pressure.

[0031] Viewed from a further independent aspect, there is provided a computer-readable medium having instructions stored thereon for performing the method according to the appended methods.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which:

Figure 1 is a schematic representation of an exemplary airflow monitor;

Figure 2 is a schematic illustration of an airflow monitor installed in an exemplary extraction fan system;

Figure 3 illustrates a further exemplary extraction fan system;

Figure 4 illustrates an alternative exemplary airflow monitor;

Figures 5A and 5B illustrate a further exemplary extraction fan system with a filter;

Figure 6 illustrates an exemplary dust extraction unit.

DETAILED DESCRIPTION

[0033] Figure 1 is a schematic representation of an exemplary airflow monitor 50. The airflow monitor 50 includes a controller 60 operatively connected to a pressure sensor 65. The pressure sensor 65 includes a high pressure port 70A and a low pressure port 70B, which allows for air to pass from the air duct 5 (see Figure 2) into the airflow monitor 50. This allows the pressure within the air duct 5 to be measured at multiple locations within the air duct 5, and for a differential pressure to be derived from these pressure measurements. While separate high 70A and low 70B pressure ports are shown, it would be apparent that this was merely exemplary and that other pressure sensors would be suitable for measuring a differential pressure in the described manner. Pitot tubes 80 can be connected to the high 70A and low 70B pressure ports to extend the respective high and low pressure channels from the monitor into the air duct 5. Thus, the monitor 50 can be fixed to the outside of the air duct 5 whilst obtaining pressure data from within the air duct 5. By way of example, one or both of the pitot tubes 80 may be 6.25mm (0.25 inch) in diameter. The airflow monitor 50 is provided with holes for securing the housing 55 of the monitor 50 to the ducting 5 using screws. However, it would be apparent other fasteners or adhesives may be used to secure the monitor in position. As the airflow monitor 50 is intended for temporary use on a site with an extraction system 1 , the fasteners are preferably releasable to allow for the airflow monitor 50 to be easily removed after a period of time.

[0034] The monitor 50 also includes a power source for operating the constituent parts of the monitor 50, such as the controller 60, the pressure sensor 65 and any transceivers 75 for communicating data to/from the monitor 50. The power source is preferably a battery, but in some cases the monitor 50 may be mains powered. Where the monitor 50 is battery- powered, this advantageously allows for the monitor 50 to be installed in a greater range of locations compared to a mains powered monitor 50. While a transceiver 75 is preferable, it would be apparent that separate receivers and transmitters may be used to communicate data to/from the monitor 50. Where a Saft LSH20 D Cell battery 3.6 V 14Ah capacity is used, the monitor 50 can operate for up to 5 months on internal battery power.

[0035] As shown in Figure 2, the monitor 50 is typically installed downstream of a fan 10 so that pressure data measured by the monitor 50 is indicative of the status of a designated fan 10. Thus, when the measured pressure data, or any airflow metrics derived from the pressure data (e.g. airflow speed) deviates from a pre-determined threshold, an installer can be alerted (e.g. via a remote device 100) and they can investigate the designated fan 10. The alert could be any of an audible, visual or haptic output. However, it would be apparent that in some cases, the airflow monitor 50 may be installed upstream of the fan 10. This is particularly the case when the fan applies a negative pressure or suction force to drawn air through the ducting 5.

[0036] As the airflow monitor 50 is designed to monitor the airflow in a ducted fan 10 to allow the installer to assess the status of any given fan 10 in real time, the airflow monitor 50 records the differential pressure in real-time and transmits this data to an online reporting platform (e.g. a remote device such as a remote server 100) which calculates the airflow speed in the duct. This allows for continuous monitoring and checking of airflow speeds in the extraction system 1. The controller 60 may sample pressure data every minute, but it would be apparent this was not essential. Furthermore, the data sampling rate may be remotely configurable, for example via the remote server 100 or using a second remote device 110 (e.g. a portable device used by an installer during maintenance tasks) that is connectable to the remote server 100 or the airflow monitor 50. The remote server 100 can alert the installer via their portable device 110 to any faults detected in the extraction system. The installer can also monitor the airflow speed in the air duct 5 in real time using their portable device 110 via the online monitoring platform provided by the remote server 100. Alternatively, the airflow monitor 50 can calculate the airflow speed based on the measured differential pressure data and output the calculated airflow speed to the online monitoring platform for remote monitoring as described above. In one example, the airflow monitor 50 includes the sensor hardware shown in Figure 1 , and a separate board or controller within the airflow monitor 50 configured to convert the pressure data to the airflow speed and pressure drop. This data is then uploaded to the platform for the customer or end-user to see. Any of the remote server 100 or the portable device 110 can download an of the measured or calculated data at a user-defined period, for example 5, 10 or 15 minute intervals. Any of the airflow monitor 50, remote server 100 or the portable device 110 can calculate the airflow speed or pressure drop data over a user-defined period, for example 5, 10 or 15 minute intervals. The airflow monitor 50 can also be configured to output the alert to one or more user-defined addresses, for example telephone numbers and/or email addresses.

[0037] The transceiver 75 communicates to the remote device 100 over a networked connection (preferably a narrowband-internet of Things connection, NB-loT). This provides a reliable, low maintenance monitor which has prolonged battery life due to the low-power wide area network used by the NB-loT connection. This also allows for the data to be uploaded to a online monitoring platform for access by any number of installers at a location remote from the extraction system or even remote from the building containing the extraction system.

[0038] An extraction system 1 can include a number of airflow monitors 50 which monitor designated fans 10. Each fan 10 may extract air from a space within a room or a room within a building as required. The monitor 50 can also be used in outdoor and indoor environments. While it is preferable for the airflow metric to be calculated remotely from the airflow monitor 50 (e.g. in the remote server 100 which provides data to the online monitoring platform), it would be apparent this was not essential, and that in some cases the remote device 110 of the installer or the airflow monitor 50 itself may calculate the airflow metric for uploading to the online monitoring platform. When the airflow speed is outside a threshold value, an installer can be alerted to the monitor 50A and/or the designated fan 10A for inspection of the air duct 5 and/or fan 10A to remove any blockages or to assess of the fan is damaged or faulty, as shown in Figure 3. While it is preferable to have one airflow monitor 50 per fan 10, it would be apparent this was not essential, and an extraction system may have more than one fan 10 monitored by a single airflow monitor 50. It would also be apparent that in some cases, the airflow metric may be the pressure measured by the pressure sensor 65 or the differential pressure calculated from the difference between the high 70A and low 70B pressure ports.

[0039] When the airflow monitor 50 is first installed, the monitor can be powered up (e.g. by pushing a power button 90 on the housing 55, see Figure 4) and the controller 60 will detect whether there is mains or battery power available and use the appropriate power source. A visual indicator 85 (e.g. an LED) is also provided to indicate the controller 60 is searching for a network connection. The device can also be calibrated for its specific location by pressing a “zeroing” button 95 on the housing 55. The fan 10 can then be powered on. Preferably, all commissioning checks, controls and data views are done online through an online monitoring platform. Preferably, the airflow monitor 50 has no local user interface. The online platform also allows installers to set thresholds for outputting alerts in the event the airflow speed deviates from the pre-set threshold values. This is particularly advantageous, being able to remotely monitor the extraction system 1 allows for an installer to monitor a large number of fans 10 without having to physically access the duct 5 or the fan 10.

[0040] Figures 5A and 5B illustrate a further exemplary extraction system. Like elements are denoted by the same reference numeral as the examples shown in Figures 1 to 4. Figure 5A shows an air duct 5 with a filter 3A disposed in the air duct 5. The filter 3A is shown upstream of the airflow monitor 50 relative to an air flow path defined by the duct 5 and indicated by the arrows shown in Figures 5A and 5B. In some cases, the airflow monitor may be mounted to, or in close proximity to, the fan 10. The fan 10 drives air through the ducting 5 along the air flow path and through the filter 3A by applying a suction force to pull air through the ducting 5. The present extraction systems 1 are for extracting dust from the air, as is commonly found on construction sites or building sites. As such, the filter 3A is preferably a dust filter. As dust is filtered from the air passing through the duct 5, the filter 3A will become clogged over time (see filter 3B in Figure 5B) and, if left in situ, will reduce the efficiency of the extraction system 1 (denoted by smaller arrows in Figure 5B compared to Figure 5A). As the fan 10 may apply the same suction force, but with a reduced airflow speed, it is preferable, but not essential to determine the status of the filter 3 using the airflow speed only. It would be apparent in some cases, the differential pressure data may be used additionally or alternatively to the airflow speed to determine the status of the filter 3.

[0041] If the differential pressure or airflow speed deviates from, e.g. drops below, a predetermined threshold, a user can then be alerted as described above. It would be apparent that any of the airflow monitor 50 and the remote device 100 could determine the status of the filter 3 based on the differential pressure and/or the air flow speed within the duct 5. For example, where the extraction system is used for extracting dust, a minimum airflow speed of 15 m/s should be maintained to ensure proper ventilation of the space. As an alternative example, where the extraction system is used for extracting fumes, for example from welding, a minimum airflow speed of 10 m/s is sufficient to ensure proper ventilation of the space. A further use-case for the present extraction system 1 is to monitor airflow in tunnels, so that a minimum airflow speed is maintained within the tunnel to achieve proper ventilation. [0042] Figure 6B illustrates a dust extraction unit 7, which is a specific type of extraction system. The dust extraction unit 7 is shown as a portable device, and can for example include wheels 2, but it would be apparent this was not essential and in some cases the dust extraction unit may be a static device. The dust extraction unit 7 includes a fan 10 for drawing air, and entrained dust, into the duct 5. This is in contrast to Figures 1 to 3 which show the fan 10 blowing air through the duct 5 using a positive pressure. As the filter 3 is upstream of the fan 10, this reduces the amount of dust reaching the fan 10 which can further improve the service life of the unit 7. The duct 5 may be formed of a rigid material, or may be formed of sections of flexible material such that an opening 4 of the duct 5 can be directed towards a dust source as required. Examples of dust sources include machinery or a user processing material in a manner which generates dust, e.g. sanding, drilling, cutting, etc.. By monitoring the status of the filter 3 in real time, a remote user can monitor multiple such dust extraction units 7 that may be distributed around a construction site, which further improves the efficiency with which the dust extraction units can be serviced, as the operator can determine when filters 3 need replacing without the need to physically inspect each dust extraction unit 7.

[0043] Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0044] Features, integers, characteristics, or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

9 CLAIMS

1 . An extraction fan system comprising: an air duct defining an air flow path, an air filter disposed in the air flow path, a fan for driving air along the airflow path through the filter, and an airflow monitor having a pressure sensor configured to measure a differential pressure within the air duct, and a controller connected to the pressure sensor and configured to transmit a signal indicative of a status of the filter via a network connection to a remote device for monitoring the status of the filter in real time.

2. An extraction fan system according to claim 1 , wherein the air filter is a dust filter.

3. An extraction fan system according to claim 1 or 2, wherein the controller is configured to calculate an airflow speed within the air duct based on the measured differential pressure data.

4. An extraction fan system according to claim 3, wherein the controller is configured to output an alert to the remote device when the airflow speed falls below a pre-determined threshold.

5. An extraction fan system according to any preceding claim, wherein the controller is configured to determine the status of the filter based on the measured differential pressure data, and wherein the controller is configured to transmit the status of the filter to the remote device.

6. An extraction fan system according to any preceding claim, wherein the controller is configured to output an alert to the remote device if the measured differential pressure data is outside a pre-determined range.

7. An extraction fan system according to any preceding claim, wherein the network connection is a low power wide area network connection.

8. An extraction fan system according to any preceding claim, wherein the pressure sensor has a measurement range of 1250 Pa.

9. An extraction fan system according to any preceding claim, wherein the controller is configured to sample the differential pressure at a pre-determined rate.

10. An extraction fan system according to any preceding claim configured as a dust extraction unit.

11. An extraction fan system according to any preceding claim, wherein the fan is arranged downstream of the filter and configured to apply a suction force to drive air through the filter.

12. An airflow monitor for use in the extraction fan system of any preceding claim.

13. A method of monitoring a status of a filter disposed in an air flow path defined by an air duct of an extraction fan system, the method comprising: measuring differential pressure data within an air duct of a fan extraction system, transmitting a signal indicative of a status of a filter within the air duct based on the measured differential pressure data via a network connection to a remote device for monitoring the status of the filter in real time, and determining the status of the filter based on the transmitted signal.

14. A method according to claim 13, comprising replacing the filter with a replacement filter when the status of the filter deviates from a pre-determined threshold.

15. A method according to claim 13 or 14, comprising calculating an airflow speed within the air duct based on the received pressure differential data, comparing the calculated airflow speed to a pre-determined threshold airflow speed, and outputting an alert to the remote device if the air flow speed is different to a pre-determined airflow speed.

16. A method according to any of claims 13 to 15, comprising outputting the status of the filter in response to an airflow monitor of the fan extraction system receiving a user input.

17. A method according to any of claims 13 to 16, wherein an airflow monitor of the fan extraction system is configured to determine the status of the filter based on the measured differential pressure data.

18. A processor having a non-volatile memory with instructions stored thereon for performing the method according to any of claims 13 to 17.