Patent Description:
Many industries encounter particulate matter suspended in the atmosphere. In some industries, this particulate matter is a valuable product (for example, starch), and it would be beneficial if the suspended particulate matter could be recovered and reintroduced into the process. For other industries (for example, metal or wood working), it may be desirable to remove the particulate matter from the air to provide a clear working environment.

Particulate matter can also be a concern in air intake streams to engines for motorized vehicles or power generation equipment, gas streams directed to gas turbines, and air streams to various combustion furnaces. In those contexts, the particulate material, should it reach the internal workings of the various mechanisms involved, can cause substantial damage thereto.

A variety of air filter or gas filter arrangements have been developed for particulate removal. In some scenarios, systems for cleaning an air or other gas stream laden with particulate matter include air filter assemblies that have filter elements disposed in a housing. The filter element may be a bag, sock or cartridge including a suitable filter media, e.g., fabric, pleated paper, etc. The gas stream contaminated with particulate matter is typically passed through the housing so that the particulate matter is captured and retained by one or more filter elements.

Document <CIT> discloses devices, systems and methods for obtaining data representative of the condition of an air filter media of an air filter, and for using such data to present an indication of the air filter media condition to a user <CIT>, <CIT>, <CIT> and <CIT> show other relevant documents.

Use of a monitoring device for a filtration system according to the invention is disclosed in any one of claims <NUM> to <NUM>.

An air filtration system according to the invention is disclosed in any one of claims <NUM> to <NUM>.

Aspects may be more completely understood in connection with the following drawings, in which:.

While embodiments are susceptible to various modifications and alternative forms, specifics thereof have been shown by way of example and drawings, and will be described in detail. It should be understood, however, that the scope herein is not limited to the particular embodiments described. On the contrary, the intention is to cover modifications, equivalents, and alternatives falling within the spirit and scope herein.

As described above, there are many scenarios in which filtering particulate matter out of air streams is useful and many different types of air filtration systems to accomplish the same. In one type of an air filtration system, the system has a clean air chamber (or clean/downstream side) and a dirty air chamber (or dirty/upstream side). The two chambers can be separated by a structure that can be referred to as a tube sheet. In many cases, the tube sheet has a number of openings so that air can pass between the clean and dirty air chambers. The filter elements can be positioned over the openings so that particulate-laden air (dirty air) introduced into the dirty air chamber must pass through a filter element to move into the clean air chamber. The particulate matter in the dirty air collects on the filter elements as the air moves through the filter elements. From the clean air chamber, the cleaned air is exhausted into the environment, or recirculated for other uses.

As the filter elements capture particulate matter, flow through the system is inhibited and periodic cleaning of the filter elements can be performed to increase air flow through the system. Cleaning can be accomplished by periodically pulsing a brief jet of air, such as pressurized air into, the interior of the filter element (which could include a filter cartridge, filter bag, or the like) to reverse the air flow through the filter element, causing the collected particulate matter to be driven off the filter element. In some cases, pressurized air can be directed into pulse collectors as described in, e.g. <CIT>), <CIT>), <CIT>), <CIT>, <CIT>), <CIT>), and <CIT>.

Keeping these air filtration systems working optimally can involve periodic maintenance including, but not limited to, replacing/cleaning filter elements, monitoring and replacing pulse valves, and the like. Monitoring aspects of the system can provide indications regarding the optimal time for performing such maintenance activities as well as identifying any other issues that may impact filtration system performance. Being able to remotely monitor such systems can be even more advantageous as information from observations of many different systems can be aggregated and analyzed and then brought to bear to increase the accuracy of determinations such as the proper time to perform system maintenance.

Many filtrations systems are constructed robustly such that their service life can span decades assuming proper maintenance is performed. As a result, however, this means that advanced technology including sensors and processors may be slow to be implemented if only provided as part of the original equipment.

In accordance with various embodiments herein, monitoring devices are included that can be easily installed on existing filtration systems that otherwise lack such monitoring capabilities. In this manner, existing filtration system can be retrofit to include advanced monitoring capabilities.

Referring now to <FIG>, a schematic front perspective view is shown of an air filtration system <NUM> with a monitoring device <NUM> in accordance with various embodiments herein. In this example, the air filtration system <NUM> depicted in <FIG> is generally in the shape of a box and includes an upper wall panel <NUM>, and two pairs of opposite side wall panels <NUM> (one of which is depicted in <FIG>). It will be appreciated, however, that the air filtration system <NUM> can take on many different shapes and configurations.

The air filtration system <NUM> includes a dirty air conduit <NUM> for receiving dirty or contaminated air (i.e., air with particulate matter therein) into the air filtration system <NUM>. A clean air conduit <NUM> (see, e.g., <FIG>) can be provided for venting clean or filtered air from the air filtration system <NUM>. The air filtration system <NUM> includes access openings <NUM> for multiple filter elements (not shown in <FIG>). In use, each of the access openings <NUM> is sealed by a cover (not shown) such that dirty air entering the air filtration system <NUM> does not escape through the access openings <NUM>.

The air filtration system <NUM> may also include a hopper <NUM> to collect particulate matter separated from the dirty air stream as described herein. The hopper <NUM> may include sloped walls to facilitate collection of the particulate matter and may, in some embodiments, include a driven auger or other mechanism for removing the collected particulate matter.

In some embodiments, the air filtration system <NUM> can include a fan <NUM> to provide movement of air through the air filtration system <NUM>. However, in other embodiments, air can be pulled through the system with a fan or other equipment that is not part of the air filtration system <NUM>. The air filtration system <NUM> can include a preexisting control box <NUM>, which can include a preexisting control circuit for the filtration system.

The monitoring device <NUM> can be connected to a first fluid conduit <NUM>, a second fluid conduit <NUM>, and third fluid conduit <NUM>. The fluid conduits can provide fluid communication between various parts of the filtration system (such as the dirty/upstream side, the clean/downstream side, a compressed air supply, etc.) and sensors/transducers that can be within or otherwise associated with the monitoring device <NUM>. The first fluid conduit <NUM> can be connected to an existing fluid conduit <NUM> of the air filtration system that provides fluid communication with an area of fluid flow that is upstream from the filtration element(s). In some embodiments, the first fluid conduit <NUM> can be connected to the existing fluid conduit <NUM> using a junction <NUM> (such as a T-junction, splice junction, or other connecting structure). The second fluid conduit <NUM> can be connected to an existing fluid conduit <NUM> of the air filtration system that provides fluid communication with an area of fluid flow that is upstream from the filtration element(s). In some embodiments, the second fluid conduit <NUM> can be connected to the existing fluid conduit <NUM> using a junction <NUM> (such as a T-junction, splice junction, or other similar connecting structure).

In some embodiments, there is no electrical communication between the preexisting control box <NUM> and/or components therein such as a preexisting control circuit and the monitoring device <NUM>. While not intending to be bound by theory, it is believed that this electronic separation can offer a security advantage as the preexisting control box <NUM> and components therein are responsible for operation of the filtration system <NUM> whereas the monitoring device <NUM> is only responsible for monitoring of the filtration system <NUM>. In this way, the monitoring device <NUM> cannot be used as a means of gaining control over operation of the filtration system <NUM>.

Referring now to <FIG>, a schematic cross-sectional view is shown of some aspects of an air filtration system <NUM> in accordance with various embodiments herein. The interior of the air filtration system <NUM> includes a tube sheet <NUM> that separates the interior of the housing into a clean air chamber <NUM> and a dirty air chamber <NUM>. The air filtration system <NUM> includes a clean air conduit <NUM> through which clean air exits from the clean air chamber <NUM> during operation of the air filtration system <NUM>.

The depicted air filtration system <NUM> includes pulse collectors <NUM> and filter elements <NUM> in the dirty air chamber <NUM> (dirty side or upstream side). The pulse collectors <NUM> are attached to the tube sheet <NUM> over an aperture in the tube sheet <NUM> (not seen in <FIG>) such that a pulse of air from the pulse generators <NUM> passing through the pulse collector <NUM> enters an interior volume of the filter elements <NUM>. Air can be provided to the pulse generators <NUM> from a compressed air manifold <NUM>, which itself can receive compressed air from an air compressor or central source of plant compressed air.

Referring now to <FIG>, a schematic rear perspective view is shown of an air filtration system with a monitoring device in accordance with various embodiments herein. <FIG> shows many of the same elements as shown in <FIG> and <FIG>, but as a rear perspective view.

Referring now to <FIG>, a schematic view is shown of a monitoring device <NUM> in accordance with various embodiments herein. The monitoring device <NUM> can include a first receptacle <NUM> or fitting to receive a tube or other conduit as part of the first fluid conduit <NUM>. The monitoring device <NUM> can also include a second receptacle <NUM> or fitting to receive a tube or other conduit as part of the second fluid conduit <NUM>. Although not shown in this figure, it will be appreciated that the monitoring device <NUM> can also include a third receptacle or fitting to receive a tube or other conduit as part of the third fluid conduit <NUM>. In addition, various embodiments herein can include greater or lesser numbers of receptacle and/or fluid conduits.

In various embodiments, the monitoring device <NUM> can be mounted on a surface of the air filtration system <NUM> such as an external surface thereof. For example, in some embodiments, the monitoring device <NUM> can be mounted on a side wall panel <NUM>. However, the monitoring device <NUM> can also be mounted in other locations including on top or bottom walls as well as inside the filtration system <NUM> and also mounted off the filtration system <NUM> (such as on a separate panel that is physically separated from other components of the system). The monitoring device can be mounted using various hardware including, but not limited to, using fasteners, adhesives, magnets, and the like. In a particular embodiment, an adhesive layer <NUM> is used to mount the housing of the monitoring device <NUM>, which can be, for example, a pressure sensitive adhesive (PSA).

Referring now to <FIG>, a schematic diagram is shown of elements of a monitoring device <NUM> in accordance with various embodiments herein. It will be appreciated that a greater or lesser number of components can be included with various embodiments and that this schematic diagram is merely illustrative. The monitoring device <NUM> can include a housing <NUM> and a control circuit <NUM>.

The control circuit <NUM> can include various electronic components including, but not limited to, a microprocessor, a microcontroller, a FPGA (field programmable gate array) chip, an application specific integrated circuit (ASIC), or the like.

The monitoring device <NUM> includes a first pressure sensor <NUM> (as used herein, reference to a pressure sensor shall include a pressure transducer unless the context dictates otherwise) and a first fluid conduit <NUM> including an internal portion <NUM> and an external portion <NUM>. The first fluid conduit can be in fluid communication with the dirty air chamber <NUM>.

The monitoring device <NUM> includes a second pressure sensor <NUM> and a second fluid conduit <NUM> including an internal portion <NUM> and an external portion <NUM>. The second fluid conduit can be in fluid communication with the clean air chamber <NUM>.

The monitoring device <NUM> includes a third pressure sensor <NUM> and a third fluid conduit <NUM> including an internal portion <NUM> and an external portion <NUM>. The third fluid conduit can be in fluid communication with the compressed air manifold <NUM>. As such, the third fluid conduit is in fluid communication with a compressed gas supply.

Pressure sensors herein can be of various types. Pressure sensors can include, but are not limited to, strain gauge type pressure sensors, capacitive type pressure sensors, piezoelectric type pressure sensors, and the like. In some embodiments, pressure sensors herein can be MEMS-based pressure sensors.

The processing power of the control circuit <NUM> and components thereof can be sufficient to perform various operations including various operations on data from sensors (such as pressure sensors <NUM>, <NUM>, and <NUM>) including, but not limited to averaging, time-averaging, statistical analysis, normalizing, aggregating, sorting, deleting, traversing, transforming, condensing (such as eliminating selected data and/or converting the data to a less granular form), compressing (such as using a compression algorithm), merging, inserting, time-stamping, filtering, discarding outliers, calculating trends and trendlines (linear, logarithmic, polynomial, power, exponential, moving average, etc.), predicting filter element EOL (end of life), identifying an EOL condition, predicting performance, predicting costs associated with replacing filter elements vs. not-replacing filter elements, and the like.

Normalizing operations performed by the control circuit <NUM> can include, but are not limited to, adjusting one or more values based on another value or set of values. As just one example, pressure drop data reflective of pressure drop across a filter element can normalized by accounting for air flow rate or a value that serves as a proxy thereof.

In various embodiments the control circuit can calculate a time for replacement of a filter element and generate a signal regarding the time for replacement. In various embodiments, the control circuit can calculate a time for replacement of a filter element and issue a notification regarding the time for replacement through a user output device. In various embodiments, the control circuit can calculate a time for replacement of a filter element based on signals from the first pressure sensor and the second pressure sensor. In various embodiments, the control circuit can calculate a time for replacement of a filter element based on signals from the first pressure sensor and the second pressure sensor and an external input. The external input can be received from a system user or from a remote location through a data communication network.

In various embodiments, control circuit initiates an alarm if a predetermined alarm condition has been met. The alarm condition can include one or more a maximum value for a signal received from the first pressure sensor, a minimum value for a signal received from the first pressure sensor, a maximum value for a signal received from the second pressure sensor, a minimum value for a signal received from the second pressure sensor, a maximum difference between a value for a signal received from the first pressure sensor and a value for a signal received from the second pressure sensor, and a minimum difference between a value for a signal received from the first pressure sensor and a value for a signal received from the second pressure sensor.

In various embodiments, the control circuit <NUM> can be configured to calculate a value correlated to a fluid flow rate through the filtration system based on a value provided by the first pressure sensor and a value provided by the second pressure sensor. In some embodiments, the control circuit <NUM> can be configured to calculate a value correlated to a fluid flow rate through the filtration system based on a static pressure value, wherein the static pressure value by a signal from at least one of the first pressure sensor and the second pressure sensor. In some embodiments, the control circuit can be configured to calculate a value correlated to a fluid flow rate through the filtration system based on a differential pressure value and a static pressure value, wherein the differential pressure value is determined by a signal from both the first pressure sensor relative and the second pressure sensor and the static pressure value by a signal from one of the first pressure sensor and the second pressure sensor.

The fluid flow rate of the system is determined by the characteristics of the motive source. For fan-based applications, the relationship between the static pressure and fluid flow is generally inverse in nature. As the system resistance increases, measured as static pressure, the fluid flow rate decreases and vice versa due to the operating characteristics of the fan. Since the fluid flow rate of the fan directly affects the fluid flow rate in other parts of the system, a fluid flow rate proxy for the fan and hence the filtration system can be calculated using the static pressure at a fixed location in the system. Generally, the static pressure in a fluid duct is proportional to the square of the fluid flow rate. As one example, the flow rate proxy value can be calculated according to the equation <MAT>, wherein FRP = flow rate proxy value, Ps is a static pressure value, Pi is the system design point static pressure, and Qi is an optional system design point fluid flow rate.

In some embodiments, a fan curve can also be used to calculate a value for a flow rate. The fan curve can be used to relate a static pressure with a flow rate. In various embodiments, the monitoring device <NUM> can store a fan curve in memory (which can be written to memory when the monitoring device <NUM> is manufactured or it can be received/updated based on data received through a network connection while the monitoring device <NUM> is being installed or after it is installed on a filtration system in the field).

In some embodiments, the monitoring device <NUM> can include an additional sensor, such as an accelerometer. For example, the monitoring device <NUM> can include a <NUM>-axis accelerometer <NUM>. The <NUM>-axis accelerometer <NUM> can be used to detect vibrations transmitted from the filtration system to the monitoring device <NUM>. The vibrations can result from various events such as periodically pulsing a brief jet of pressurized air into the interior of the filter element to reverse the air flow through the filter element and/or valve(s) opening or closing to accomplish the same.

In some cases, it can be helpful to mount an accelerometer in the monitoring device <NUM> such that it receives vibrations from the filtration system with minimal diminishment of vibration in terms of frequency range and amplitude. In some embodiments, the accelerometer can be disposed within the housing such that vibrations incident upon a contact surface of the monitoring device housing are attenuated by less than <NUM>% as incident upon the accelerometer. In some embodiments, the accelerometer can be disposed within the housing such that vibrations incident upon a contact surface of the monitoring device housing are attenuated by less than <NUM>% as incident upon the accelerometer.

In various embodiments, the monitoring device <NUM> can include a power supply circuit <NUM>. In some embodiments, the power supply circuit <NUM> can include various components including, but not limited to, a battery <NUM>, a capacitor, a power-receiver such as a wireless power receiver, a transformer, a rectifier, and the like.

In various embodiments the monitoring device <NUM> can include an output device <NUM>. The output device <NUM> can include various components for visual and/or audio output including, but not limited to, lights (such as LED lights), a display screen, a speaker, and the like. In some embodiments, the output device can be used to provide notifications or alerts to a system user such as current system status, an indication of a problem, a required user intervention, a proper time to perform a maintenance action, or the like.

In various embodiments the monitoring device <NUM> can include memory <NUM> and/or a memory controller. The memory can include various types of memory components including dynamic RAM (D-RAM), read only memory (ROM), static RAM (S-RAM), disk storage, flash memory, EEPROM, battery-backed RAM such as S-RAM or D-RAM and any other type of digital data storage component. In some embodiments, the electronic circuit or electronic component includes volatile memory. In some embodiments, the electronic circuit or electronic component includes non-volatile memory. In some embodiments, the electronic circuit or electronic component can include transistors interconnected to provide positive feedback operating as latches or flip flops, providing for circuits that have two or more metastable states, and remain in one of these states until changed by an external input. Data storage can be based on such flip-flop containing circuits. Data storage can also be based on the storage of charge in a capacitor or on other principles. In some embodiments, the non-volatile memory <NUM> can be integrated with the control circuit <NUM>.

In various embodiments the monitoring device <NUM> can include a clock circuit <NUM>. In some embodiments, the clock circuit <NUM> can be integrated with the control circuit <NUM>. While not shown in <FIG>, it will be appreciated that various embodiments herein can include a data/communication bus to provide for the transportation of data between components. In some embodiments, an analog signal interface can be included. In some embodiments, a digital signal interface can be included.

In various embodiment the monitoring device <NUM> can include a communications circuit <NUM>. In various embodiments, the communications circuit can include components such as an antenna <NUM>, amplifiers, filters, digital to analog and/or analog to digital converters, and the like.

In various embodiments, monitoring devices <NUM> herein are designed so that they can operate using only a battery for power and not deplete the battery for a long period of time such as weeks, months, or even years. As such, in various embodiments operations of the monitoring device <NUM> can be optimized to conserve energy consumption.

In some embodiments, the control circuit initiates a transitory change in a data recording parameter based on a signal received from the third pressure sensor. In some embodiments, the transitory change in the data recording parameter comprises increasing the resolution of the recorded data. In some embodiments, the transitory change in the data recording parameter includes changing the resolution of the recorded data. In some embodiments, changing the resolution can include increasing or decreasing the sampling frequency.

In some embodiments, the first pressure sensor and the second pressure generate signals discontinuously. In some embodiments, the first pressure sensor and the second pressure generate signals at predetermined time intervals.

Referring now to <FIG>, a schematic diagram is shown of elements of a monitoring device <NUM> in accordance with various embodiments herein. <FIG> includes various components as shown in <FIG>. As depicted in <FIG>, the monitoring device <NUM> can also be in electrical communication with an DC power source and/or can include a transformer <NUM>. The monitoring device <NUM> can also include an input interface <NUM> and/or user input device.

The monitoring device <NUM> can also include a low-energy local wireless communication component <NUM>. In some embodiments, the low-energy local wireless communication component <NUM> can include a Bluetooth component. In some embodiments, the monitoring device <NUM> can also include a wired I/O interface <NUM> and one or more wire connection ports or plug receptacles <NUM>.

The monitoring device <NUM> can include various other sensors. In some embodiments, the monitoring device <NUM> can also include a temperature sensor <NUM>. The temperature sensor <NUM> can be in fluid communication with at least one of the first fluid conduit, the second fluid conduit, and the third fluid conduit.

In some embodiments, the monitoring device <NUM> can also include a humidity sensor <NUM>. In some embodiments, the monitoring device <NUM> can also include a sound sensor <NUM>, such as a microphone. The sound sensor can <NUM> can be in fluid communication with at least one of the first fluid conduit, the second fluid conduit, and the third fluid conduit.

Referring now to <FIG>, a schematic view is shown of a filtration system data communication environment <NUM> in accordance with various embodiments herein. The communication environment <NUM> can include an air filtration system <NUM>, such as a dust collector. In some embodiments, the filtration system <NUM> can be within a work environment <NUM>. The work environment <NUM> can represent a geographic area in which the air filtration system <NUM> operates. The work environment <NUM> can be, for example, a shipping or distribution center, a manufacturing facility, or the like.

In some embodiments, wireless signals from the filtration system <NUM> can be exchanged with a wireless communication tower <NUM> (or antenna array), which could be a cellular tower or other wireless communication tower. The wireless communication tower <NUM> can be connected to a data network <NUM>, such as the Internet or another type of public or private data network, packet-switched or otherwise.

The data network can provide for one-way or two-way communication with other components that are external to the work environment <NUM>. For example, a server <NUM> or other processing device can receive electronic signals containing data from one or more components such as the filtration system <NUM>. The server <NUM> can interface with a database <NUM> to store data. In some embodiments, the server <NUM> (or a device that is part of the server system) can interface with a user device <NUM>, which can allow a user to query data stored in the database <NUM>. The server <NUM> and/or the database <NUM> can be at a distinct physical location or can be in the cloud.

Referring now to <FIG>, a schematic view is shown of a filtration system data communication environment <NUM> in accordance with various embodiments herein. In some embodiments, a gateway or repeater unit <NUM> can be disposed within the work environment <NUM>. The gateway or repeater unit <NUM> can, in some embodiments, communicate wirelessly with the filtration system <NUM>. In some embodiments, the gateway or repeater unit <NUM> can be connected to an external data network <NUM>, such as the Internet or various private networks. In some embodiments, the data network <NUM> can be a packet-switched network. In some embodiments, the gateway or repeater <NUM> can also include data network router functionality.

In some embodiments, pressure sensors can be located remotely from the monitoring device <NUM>, but in electrical communication with the monitoring device <NUM>, such as in electrical communication with the control circuit <NUM>. For example, referring now to <FIG>, a schematic front perspective view of an air filtration system <NUM> with a monitoring device is shown in accordance with various embodiments herein. In contrast to the system shown in <FIG>, in this example, pressure sensors are disposed at or in a junction <NUM>, <NUM> with existing fluid conduits <NUM>, <NUM> of the air filtration system and signals from the pressure sensors are relayed back to the monitoring device <NUM> via wires <NUM>, <NUM>.

Claim 1:
Use of a monitoring device (<NUM>) for a filtration system (<NUM>) comprising:
a first fluid conduit (<NUM>);
a first pressure sensor (<NUM>), wherein the first pressure sensor (<NUM>) is in fluid communication with the first fluid conduit (<NUM>);
a second fluid conduit (<NUM>);
a second pressure sensor (<NUM>), wherein the second pressure sensor (<NUM>) is in fluid communication with the second fluid conduit (<NUM>); and
a control circuit (<NUM>) in electronic communication with the first pressure sensor (<NUM>) and the second pressure sensor (<NUM>);
a housing (<NUM>), wherein the first pressure sensor (<NUM>), the second pressure sensor (<NUM>) and the control circuit (<NUM>) are all disposed within the housing (<NUM>), characterized by the fact that the monitoring device (<NUM>) further comprises:
a third fluid conduit (<NUM>); and
a third pressure sensor (<NUM>) within the housing (<NUM>) and in fluid communication with the third fluid conduit (<NUM>);
wherein the third fluid conduit (<NUM>) is in fluid communication with a compressed gas supply.