METHOD AND SYSTEM FOR AUTOMATED CLEANING OF FILTER WALL FOR HVAC SYSTEMS
20240100461 ยท 2024-03-28
Inventors
Cpc classification
F24F13/222
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F11/39
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B01D2273/30
PERFORMING OPERATIONS; TRANSPORTING
B01D46/4263
PERFORMING OPERATIONS; TRANSPORTING
F24F2221/225
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B01D46/69
PERFORMING OPERATIONS; TRANSPORTING
International classification
F24F11/39
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F13/22
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B01D46/69
PERFORMING OPERATIONS; TRANSPORTING
Abstract
Devices, systems, and methods for the automated cleaning of filters and filter walls within heating, ventilation, and air-conditioning (HVAC) systems. Disclosed devices can include self-cleaning filter assemblies configured to receive and surround at least one filter, such as an HVAC filter. In some embodiments, the self-cleaning assemblies receive and surround at least one filter and at least one fan. For example, at least one filter or filter wall comprising multiple filters and fan may be combined together into a single cube, where the cube is then received and surrounded by the self-cleaning casing. In some embodiments, the self-cleaning assemblies or cubes receive and surround at least one filter, at least one fan, and at least one heat transfer coil. The cleaning system can have different cleaning cycles, such as a cleaning cycle that cleans the filter(s) and a different cleaning cycle that cleans the heat transfer coil.
Claims
1. A self-cleaning filter assembly for use in a heating, ventilation, and air-conditioning (HVAC) system, the self-cleaning filter assembly comprising: a casing having a plurality of injection ports positioned along a top edge and a bottom edge of the casing, wherein the injection ports are configured to deliver a cleaning solution to a face of the filter; and a filter housed within the casing and positioned behind the plurality of injection ports such that the face of the filter is behind the plurality of injection ports.
2. The self-cleaning filter assembly of claim 1, further comprising a fan housed within the casing and disposed in front of the filter.
3. The self-cleaning filter assembly of claim 1, further comprising a heat transfer coil housed within the casing.
4. The self-cleaning filter assembly of claim 1, further comprising a plurality of sensors mounted within the casing.
5. The self-cleaning filter assembly of claim 4, wherein at least one of the plurality of sensors is a pressure sensor.
6. The self-cleaning filter assembly of claim 5, wherein the pressure sensor is configured to sense an air pressure or air flow across the filter.
7. The self-cleaning filter assembly of claim 5, wherein the pressure sensor is configured to communicate an air pressure or air flow across the filter to a central controller.
8. The self-cleaning filter assembly of claim 5, wherein the pressure sensor is configured to trigger a cleaning process when air pressure across the filter satisfies a threshold value.
9. The self-cleaning filter assembly of claim 8, wherein the threshold value comprises an approximately 1-5% change in air pressure across the filter compared to an air pressure the filter was designed to withstand.
10. The self-cleaning filter assembly of claim 1, further comprising one or more nozzles for emitting aerosolized enzymes into an air stream on a downstream side of the filter wall for application to heat transfer coils of the HVAC system.
11. An automated cleaning system for cleaning HVAC filters of an HVAC system, the automated system comprising: a self-cleaning filter assembly; a central system comprising a controller, an air handler, and a reservoir tank; and at least one tube connecting the self-cleaning filter assembly to the reservoir tank of the central system.
12. The automated cleaning system for cleaning HVAC filters of claim 11, wherein the self-cleaning filter assembly comprises: a casing having a plurality of injection ports, at least one positioned along a top edge and at least one along a bottom edge of the casing, wherein the injection ports are configured to receive a cleaning solution from the reservoir tank; and a filter housed within the casing and positioned behind the injection ports such that a face of the filter is behind the injection ports and receives the cleaning solution from the injection ports.
13. The automated cleaning system of claim 11, wherein the reservoir tank is connected to a water line.
14. The automated cleaning system of claim 11, wherein the reservoir tank is configured to receive condensed water from cooling coils of the HVAC system.
15. The automated cleaning system of claim 11, wherein the automated system includes a plurality of self-cleaning filter assemblies (i) arranged as a filter wall and (ii) arranged with a tight tolerance such that no gaps are left between each of the plurality of self-cleaning filter assemblies, such that the system eliminates filter bypass.
16. The automated cleaning system of claim 11, further comprising one or more nozzles that emit aerosolized enzymes into an air stream on a downstream side of the filter for application to heat transfer coils of the HVAC system.
17. A method of automatically cleaning an HVAC filter of an HVAC system, the method comprising: providing the self-cleaning filter assembly of claim 1; and flushing a cleaning solution through the self-cleaning filter assembly, whereby flushing the cleaning solution through the self-cleaning filter assembly automatically cleans the HVAC filter of the HVAC system.
18. The method of claim 17, further comprising: providing a water line as a source of water for making the cleaning solution; mixing water with one or more reagents to form the cleaning solution; and delivering the cleaning solution to injection ports.
19. The method of claim 17, further comprising: collecting condensate water from the evaporative coil(s) of the HVAC system; and using the condensate water as an auxiliary or alternate source of water for making the cleaning solution.
20. The method of claim 17, further comprising emitting aerosolized enzymes into an air stream on a downstream side of the filter and applying the enzymes to heat transfer coils of the HVAC system.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Various objects, features, characteristics, and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings and the appended claims, all of which form a part of this specification. In the Drawings, like reference numerals may be utilized to designate corresponding or similar parts in the various Figures, and the various elements depicted are not necessarily drawn to scale, wherein:
[0021]
[0022]
[0023]
[0024]
DETAILED DESCRIPTION
[0025] Disclosed are devices, systems, and methods for automated cleaning of filters and filter walls within HVAC systems. Disclosed devices can include self-cleaning assemblies configured to receive and surround at least one filter, which may be an HVAC filter. The self-cleaning filter assemblies include, at least, one or more self-cleaning casings. In some embodiments, the one or more self-cleaning casings each receive and surround at least one filter and at least one fan. For example, at least one filter and fan may be combined together into a single assembly (e.g., cube), which is then received and surrounded by the self-cleaning casing. The fan is included to cause air to flow through the casing and the self-cleaning filter assembly. In some embodiments, the self-cleaning casings receive and surround at least one filter, at least one fan, and at least one heat transfer coil. The cleaning system can have different cleaning cycles, such as a cleaning cycle that cleans the filter(s) and a different cleaning cycle that cleans the heat transfer coil.
[0026] The filters and filter walls can be used with existing and/or standard HVAC systems. In some embodiments, the filters and filter walls can be used with the new cube HVAC systems disclosed in U.S. application Ser. No. 18/455,433, filed Aug. 24, 2023, and entitled Closed Loop, Modular And Self-Cleaning HVAC system, which is incorporated herein by reference in its entirety.
[0027] In some embodiments, the self-cleaning casings are sized and shaped to receive and surround an HVAC filter. Specifically, the self-cleaning casings can be substantially cuboid or rectangular cuboids, meaning the casings have a top, bottom and sides. The self-cleaning casings include at least two (2) injection ports disposed and positioned along the top edge or surface of the self-cleaning casing. The self-cleaning casings can also include a plurality of injection ports disposed and positioned along opposing side edges or surfaces of the self-cleaning casing. Drainage ports may be included, such as on the bottom edge or surface of the casing surrounding the filter(s). It is also possible for waste water from the filter cleaning cycle can flow out and down the front and/or rear sides of the filter(s) toward a drain or collection basin below the filter(s).
[0028] Disclosed systems can include at least one filter assembly in communication with a central system. The at least one filter assembly includes at least one self-cleaning casing that receives and surrounds at least one filter. In some embodiments, multiple self-cleaning filter assemblies or modules can be joined together to form a single filter wall. The at least one filter assembly can further include at least one fan and/or at least one heat transfer coil. The central system can include, at least, one or more liquid pumps, one or more air compressors, one or more reservoir tanks, and one or more programmable logic control boards.
[0029] Also disclosed are methods of automatically cleaning filters and/or filter walls of an HVAC system. The methods can include, for example, providing a self-cleaning filter assembly and running an automated cleaning process. The automated cleaning process may be governed and/or controlled by a programmable logic controller (PLC) that is part of a central system and in communication with the self-cleaning filter assembly. Running the automated cleaning process may include: (i) providing a water line as a source of water for making a cleaning solution; (ii) optionally collecting condensate water from the evaporative coil(s) of an HVAC system as an auxiliary or alternate source of water for making the cleaning solution; (iii) mixing water with one or more reagents to form the cleaning solution; (iv) delivering the cleaning solution to a plurality of injection ports disposed within the self-cleaning filter assembly; and (v) flushing the cleaning solution through the self-cleaning filter assembly, thereby cleaning the filter of the HVAC system. The wastewater from cleaning the filters or filter wall can be disposed of through a drain or it can be cleaned (e.g., filtered) and reused. The cleaning system can have different cleaning cycles, such as a cleaning cycle that cleans the filter(s) and a different cleaning cycle that cleans the heat transfer coil(s).
[0030] In some embodiments, condensed water from the cooling coils of an HVAC system can be recovered and utilized to clean the filters, such as by using the condensed water to make the cleaning solution. This can reduce installation costs by eliminating installation of water lines. The recovered condensate can be used when there is not a ready supply of available water and/or to augment or supplement water already available to reduce cost and save water. The condensate is distilled water and therefore potentially cleaner than municipal water (e.g., will typically be mineral free and possibly more sterile if the coils are clean).
[0031] In some embodiments, the self-cleaning filter assemblies can be configured with one or more nozzles or other means configured to periodically emit aerosolized enzymes into the air stream on the downstream side of the filter wall. The aerosolized enzymes can be drawn into the heat transfer coils, and this automated process of regularly injecting enzymes into the coils can inhibit microbial fouling of the coils, ensuring that both the filter wall and heat transfer coils are operating at their design delta P's (pressure differential) for peak efficiency.
[0032]
[0033] As illustrated in
[0034] The filter 110 is housed within the casing 115. Typically, the filter 110 will be positioned or installed within the casing 115 so that filter 110 will rest just behind the injection ports 120. The primary purpose of the injection ports 120 is to inject or spray a viscous cleaning foam or non-viscous cleaning solution directly toward the face of the filter 110 (e.g., the air intake side so that the cleaning foam or solution is drawn into and through the filter 110 by air flow, such as by the air handler of the HVAC system). Positioning the filter 110 behind the plurality of injection ports 120 allows the cleaning foam or solution to flow out of the ports 120 and directly onto the front face of the filter 110. The cleaning foam or solution can then flow or fall down the front face of the filter 110, thereby substantially covering the entire front face of the filter 110. When the cleaning solution is subsequently pulled through the filter 110, the filter 110 will be completely cleaned and de-clogged. The dirty water can exit the back face of the filter 110 and flow down toward a drain or collection basin (not shown).
[0035] The cleaning foam or solution can include any combination of air, water, enzymes, chemicals, and surfactants in order to achieve desired cleaning attributes. Examples of foams or other cleaning solutions that may be utilized with the disclosed devices, systems, and methods are described in U.S. Pat. Pub. No. 2023/0280116 and U.S. Pat. Pub. No. 2023/0258421, which are incorporated herein by reference in their entirety.
[0036] In addition, other cleaning agents such as enzymes and other chemicals can be introduced to the cleaning solution formula depending on the operating environment. The utilized cleaning solution can be customized for the particular needs of any given building or facility. For example, in industrial applications such as paint booth operations, it may be advantageous to inject a paint thinning formulation into the cleaning solution to assist in breaking down any fine particles captured from this air stream. In other applications, introduction of varying degreasers may assist in removing hydrocarbon-based particles.
[0037] Injecting a thick cleaning foam or solution onto the face of the filter 110 removes any particulates that have been captured in the filter media (i.e., the fibers of the filter), and migrates these particles out of the filter media. This is accomplished by first injecting the thick cleaning foam or solution into the front face of the filter 110 while air is flowing through the filter casing 115. The air flow will pull the thick cleaning foam or solution through the filter 110 and the interior of the casing 115. As the cleaning foam or solution migrates through the filter 110 and casing 115, any organic and/or inorganic particles will be encapsulated into the thick cleaning foam or solution, gently removing these particles from the fibers of the filter 110. Migrating the cleaning foam or solution through the casing 115 in this way maintains the integrity of the fibers of the filter 110.
[0038] In some embodiments, the filters 110 are constructed with a synthetic polymer filter media, such as fibers of polypropylene, polyethylene, a similar synthetic fiber, and/or combinations thereof. These materials are capable of being wetted without degradation of the filter fibers. As the cleaning foam or solution migrates through the synthetic filter media and removes the captured particulates from within the filter media, the cleaning foam or solution and the encapsulated particulates will then collect into a drain or collection basin (not shown) incorporated into the bottom of the casing 115. The fouling particulates can then simply be flushed down the drain, leaving the filter 110 particulate free. The filter 110 is then ready to filter and clean the air stream flowing through the HVAC system.
[0039] In some embodiments, the cleaning foam or solution can be a thick, shaving cream-like foam. In some embodiments, the cleaning foam or solution can be formulated to deposit a negative charge on the filter media as it moves through the filter 110 and removes inorganic and/or organic particles from the filter media. This introduction of an ionic static charge can further enhance the filtration effect of the filter media by attracting new incoming particles as they pass through the filter 110.
[0040] In addition to a thick cleaning foam or solution, less viscous cleaning solutions can also be used to flush and clean the filters 110 contained within the casing 115. For example, the injection ports 120 can deliver aqueous-based cleaning solutions or plain water. In some embodiments, a thick cleaning foam or solution is first flushed through the casings 115 to collect and migrate out particulates contained within the filter 110. An aqueous-based solution or plain water can then be flushed through the casings 115. Running water through the casing 115 after the thick cleaning foam or solution helps remove any remaining particulates and/or cleaning foam or solution from the filter 110.
[0041] Placing a plurality of injection ports 120 along the top and bottom edges (and optionally along the sides) of the casing 115 allows cleaning solution to flow around and through substantially all portions of the filter 110. Gravity will assist in pulling the injected cleaning solution down the face of the filter 110. Providing more injection ports 120 at various points of the casing 115 means a higher volume of cleaning solution can be applied, resulting in no gaps or spaces on the face of the filter 110 without applied cleaning solution. A higher volume of injected cleaning solution ensures the filter 110 is fully and properly cleaned, removing all particulates present and captured in the filter media.
[0042] In some embodiments, one or more sensors (not shown) can be mounted within the casing 115. The one or more sensors may be mounted or embedded on or around a perimeter of the casing 115 that interfaces with the filter 110. For example, temperature, volume, and/or pressure sensors can be mounted on or within the casing 115. Pressure sensors can be configured to monitor and measure the delta P (or air pressure differential) across the filter 110. When the delta P across the filter satisfies a threshold level (i.e., equals or exceeds a threshold pressure drop across the filter), the pressure sensor can communicate this change to a central system (discussed more below), indicating that the filter 110 needs to be cleaned. The central system can then automatically execute a cleaning process.
[0043] In some embodiments, the threshold delta P can be a change of approximately 1-5% in air pressure flowing across the filter compared to the air pressure or delta P the filter was designed to withstand. In some embodiments, the filters 110 are initially configured for a delta P range of 0.04 inches of water guage (In-Wg) to 1.5 In-Wg (or approximately 0.05 pounds-per-square-inch), such as 0.05 In-Wg, 0.1 In-Wg, 0.3 In-Wg, 0.5 In-Wg, 1.0 In-Wg, or a range defined by any two of the foregoing values. As the filters 110 become clogged with particulates, the delta P range can climb to approximately 2-4 In-Wg, such as 2.5 In-Wg, 3 In-Wg, 3.5 In-Wg, or a range defined by any two of the foregoing values.
[0044]
[0045] In some embodiments, the casing 115 is sized and shaped to house a filter 110. For example, the casing 115 may have a 12?12 (e.g., 12 inches by 12 inches) opening to receive a 12?12 filter 110. Alternatively, the casing 115 can have a 6?6 opening, an 8?8 opening, a 10?10 opening, a 14?14 opening, a 16?16 opening, an 18?18 opening, a 22?22 opening, a 24?24 opening, or an opening defined by any two of the foregoing values, in order to house a correspondingly-sized filter 110. The size of the opening for the casing 115 is influenced by how the cleaning and drainage systems of a building or facility are configured. The casing 115 can have a depth ranging from 3 (inches) to 36 (inches), such as 4, 5, 6, 8, 10, 12, 20, 24, 32, or a range defined by any two of the foregoing values. The casing 115 can also be sized and shaped to form a tight fit with the filter 110. The tight fit eliminates any air gaps between the casing 115 and the filter 110, reducing or eliminating bypass flows that otherwise might be present.
[0046] These various shape and sizing configurations allow self-cleaning assemblies and systems (discussed below) to be incorporated into any existing HVAC system. For example, if a large air handler needs to be retrofitted so that only a self-cleaning filter wall is installed (see
[0047]
[0048] The PLC 210 can include a plurality of sensors and microprocessor units configured to track and control an automated cleaning process. For example, the PLC 210 can include temperature sensors, timers, volume sensors, pressure sensors, and other sensors that are configured to assist in running an automated cleaning process. Examples of PLC and other circuit boards that can be utilized with the disclosed devices, systems, and methods are outlined in U.S. Pat. Pub. No. 2023/028116, already incorporated herein by reference. The PLC 210 can also control a mixture or formula of the cleaning solution, thereby controlling which solution gets delivered to the self-cleaning filter assemblies. For example, including paint thinner (e.g., mineral spirits) in the cleaning solution may be desirable. In this case, the PLC 210 would control the ultimate formula of the cleaning solution, including the paint thinner, that gets mixed and delivered to the self-cleaning filter assemblies. In cases where paint thinner is not desired, the PLC 210 would adjust the formula of the cleaning solution accordingly. Thus, the PLC 210 exhibits a degree of control over customization of the cleaning solution ultimately flushed through the self-cleaning filter assemblies.
[0049] The plurality of sensors and microprocessor units of the PLC 210 can be in communication with the sensors mounted and disposed within the casing of the self-cleaning assemblies of
[0050] As also shown in
[0051] In some embodiments, the self-cleaning assemblies 100 include a heat transfer coil and fan housed within each of the casings (not shown). Arrangement of the self-cleaning assemblies 100 forms a mono-coil wall along with a fan array wall, where the fan array wall is positioned in front of both the filter wall and the mono-coil wall. The fan array wall is often comprised of segmented fans that can individually turn on or off to regulate the total air flow of the system. Additionally, and/or alternatively, the self-cleaning filter wall can be installed with each casing outfitted with a dedicated fan, that can also be 6?6 to 12?12 in size, whereby the filter and the fan are combined into a single cube. During normal operation of the HVAC system, air flow is pulled through the filter and then through the coil wall. In yet another example, the filter, coil, and fan are all contained within one casing, whereby the air flows through the air handler and then through these modular assemblies, all of which are connected together into on singular filter, coil, fan array wall within the air handler.
[0052]
[0053] As shown in
[0054] The method 500 includes delivering a cleaning solution to injection ports within the self-cleaning filter assembly, at step 525. The self-cleaning filter assembly can include a plurality of injection ports disposed along top, bottom, and side edges of a casing of the self-cleaning filter assembly. The method 500 also includes flushing the cleaning solution through the self-cleaning filter assembly, thereby cleaning a filter housed within the self-cleaning filter assembly, at step 530. The cleaning solution may be drawn through the self-cleaning filter assembly by an air compressor or fan.
[0055] In some embodiments, the disclosed methods can additionally include flushing water or another aqueous-based cleaning solution through the self-cleaning filter assembly after the cleaning solution has been flushed through the self-cleaning filter assembly. Flushing water or another aqueous-based cleaning solution through the self-cleaning filter assembly assists in removing any particulates and/or cleaning solution clinging to the fibers of the filter. In some embodiments, the disclosed methods may be computer-implemented methods controlled by a programmable logic controller (PLC), such as PLC 210.
Additional Terms & Definitions
[0056] While certain embodiments of the present disclosure have been described in detail, with reference to specific configurations, parameters, components, elements, etcetera, the descriptions are illustrative and are not to be construed as limiting the scope of the claimed invention.
[0057] Furthermore, it should be understood that for any given element of component of a described embodiment, any of the possible alternatives listed for that element or component may generally be used individually or in combination with one another, unless implicitly or explicitly stated otherwise.
[0058] In addition, unless otherwise indicated, numbers expressing quantities, constituents, distances, or other measurements used in the specification and claims are to be understood as optionally being modified by the term about or its synonyms. When the terms about, approximately, substantially, or the like are used in conjunction with a stated amount, value, or condition, it may be taken to mean an amount, value or condition that deviates by less than 20%, less than 10%, less than 5%, less than 1%, less than 0.1%, or less than 0.01% of the stated amount, value, or condition. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
[0059] Any headings and subheadings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims.
[0060] It will also be noted that, as used in this specification and the appended claims, the singular forms a, an and the do not exclude plural referents unless the context clearly dictates otherwise. Thus, for example, an embodiment referencing a singular referent (e.g., widget) may also include two or more such referents.
[0061] It will also be appreciated that embodiments described herein may also include properties and/or features (e.g., ingredients, components, members, elements, parts, and/or portions) described in one or more separate embodiments and are not necessarily limited strictly to the features expressly described for that particular embodiment. Accordingly, the various features of a given embodiment can be combined with and/or incorporated into other embodiments of the present disclosure. Thus, disclosure of certain features relative to a specific embodiment of the present disclosure should not be construed as limiting application or inclusion of said features to the specific embodiment. Rather, it will be appreciated that other embodiments can also include such features.