1. Field of the Invention
The present disclosure generally relates to an air cleaner for removing particles from air. The present disclosure more specifically relates to using a reverse flow combustion purifier for converting the particles to a residue, which may be used to reduce power consumption by the purifier.
2. Description of Related Art
A gas may include suspended particulate matter, which is sometimes referred to as particulates or particles. The size of particulates may vary across a spectrum. Particulates may be representative of tiny or large solids or liquids suspended in a gas. For example, smaller particulates may be representative of individual molecules. More intermediate sized particulates may be representative of material many microns in diameter and may produce a visible haze. Larger particulates may encompass visible objects such as dust and insects.
Particulates may include organic material such as hydrocarbons. Another type of particulate includes elemental carbon, which is also known as black carbon or soot. Black carbon is composed of pure carbon clusters, skeleton balls, and Bucky balls. Organic matter and elemental carbon together constitute the carbonaceous particulate matter. The gas may include ambient air or gas emitted by an industrial process.
Some particulates are suspended in the atmosphere by natural events such as volcanoes, dust storms, forest and grassland fires, sea spray, living vegetation and animals. Some particulates are contributed by activities such as vehicle traffic, burning fossil fuels, and power plant burn off.
Particulates can be damaging to property and harmful to health. Thus, methods have been developed to remove particulates from air. One method of removing particulates from air is to filter the air. While filtering is generally adequate for small volumes of air, such as inside rooms and buildings, it is inadequate for large volumes of air surrounding buildings, towns, and cities. Filtering also requires substantial amounts of energy for moving the air through a resistance presented by the filter. Further, filters must be cleaned or replaced as they become saturated by particulates.
Another method for removing particulates from air is to convert the particulates to a residue. The residue may be non-harmful or more easily removed. One form of conversion is oxidation of particulates. A temperature of the gas may be raised to a combustion temperature of the particulates and oxygen or other oxidizing agent in the gas may combine with the particulates to produce a particulate residue. For example, various forms of carbon particulates including elemental carbon, carbon monoxide, carbohydrates, organic carbon molecules, hydrocarbons may be oxidized to produce a residue including CO2 and H2O. A reduction reaction may also be used to convert particulates to a residue. The temperature of the gas may be raised to a reduction temperature of the particulates and the particulates may be reduced in the presence of a reducing agent or in the absence of an oxidizing agent. For example, oxides of nitrogen (NOx) may be reduced (unburned) in the presence of high energy molecules such as HC and CO. The high energy molecules may receive oxygen from the NOx to produce a residue including N2.molecules. However, there is no method for oxidizing or reducing particulates in large volumes of air.
In an embodiment of the presently claimed invention, a system is provided for converting particles to particle residue. The system includes a compressor configured to compress a gas including the particles. A reverse flow combustion purifier receives the compressed gas and the particles from the compressor and heats the compressed gas and particles to a combustion temperature of the particles. Combustion of the particles converts the heated particles to particle residue. The reverse flow combustion purifier may output the particle residue and heated compressed gas to a turbine. The turbine is configured to receive the heated compressed gas from the reverse flow combustion purifier and use the heated compressed gas for producing power. The turbine is coupled to the compressor and configured to provide the produced power to the compressor for driving the compressor.
In an embodiment of the presently claimed invention, a method is provided for converting particles in a gas to a residue. The method includes compressing the gas in a compressor and heating the particles in the compressed gas to a first temperature. The particles are heated in a reverse flow combustion purifier. The method further includes combusting the heated particles in the reverse flow combustion purifier to convert the heated particles to a particle residue. The heated compressed gas is provided from the reverse flow combustion purifier to a turbine. The heated compressed gas is used for driving the turbine to generate power. The power generated in the turbine is provided to the compressor to use for compressing the gas.
In an embodiment of the presently claimed invention, a system is provided for converting particles to particle residue. The system includes a compressor and a reverse flow combustion purifier. The compressor is configured to compress a gas to a first pressure, the gas including particles. The reverse flow combustion purifier includes an intake chamber, a combustion chamber, and an exit chamber. The intake chamber is configured to receive the compressed gas from the compressor at the first pressure. The combustion chamber is configured to receive the compressed gas from the intake chamber and heat the compressed gas and included particles to a combustion temperature of the particles to generate a particle residue from combustion of the particles. The exit chamber is configured to receive the particle residue and the heated compressed gas from the burner chamber and to expel the particle residue and the heated compressed gas from the combustion purifier. The reverse flow combustion purifier further includes a thermal conductor disposed between the intake chamber and the exit chamber. The thermal conductor is configured to transfer heat from the heated compressed gas and particle residue in the exit chamber to the compressed gas in the intake chamber. The system may further include a turbine coupled to the reverse flow combustion purifier. The turbine may be configured to receive the heated compressed gas from the reverse flow combustion purifier. The heated compressed gas may be used for driving the turbine to generate power. The turbine may be further coupled to the compressor and configured to provide the generated power to the compressor.
The platform 110 of
The combustion purifier 230 of
The turbine 220 receives the heated compressed gas from the combustion purifier 230. The heated compressed gas is used for driving the turbine 220. Exit gas may be output from the turbine 220 via the outlet manifold 124. The outlet manifold 124 is configures to release the exit gas to ambient air via the outlet 114.
The turbine 220 is coupled to the compressor 210 via a coupling 222. Power and/or torque from the turbine 220 may be used for driving the compressor 210. Examples of the coupling 222 include a drive shaft, transmission, pneumatics, electrical motors, and electrical conductors.
One or more valves may be used for controlling volume and flow of gas in the air purifier system 120. Examples include valves 232 and 234. The valve 232 may be implemented to control a volume and/or rate of compressed gas received by the combustion purifier 230 from the compressor 210. The valve 234 may be implemented to control a volume and/or rate of the heated compressed gas received by the turbine 220 from the combustion purifier 230.
The air purifier system 120 may operate in a closed loop mode. An example of a closed loop includes the compressor 210, the turbine 220 and the combustion purifier 230. Energy losses due to inefficiencies such as friction, entropy, turbulence, drag in the turbine, drag in the compressor are inherent in such a closed loop system. Closed loop operation of the air purifier system 120 generally is not self-sustaining without a source of additional energy or ‘make-up’ energy to compensate for such losses. Make-up energy may be added to sustain operation of the air purifier system 120 in a closed loop mode.
Make-up energy may be provided from a number of sources. The energy produced by an exothermic reaction between the particulates and the compressed gas can be a source of make-up energy for the air purifier system 120. For example, oxidation of particulates may provide sufficient heat energy to sustain operation of the air purifier system 120 in the closed loop mode. This may occur when the particulates are highly concentrated in the compressed gas and/or have a high energy content. Examples include heavily polluted air or a swarm of insects.
Typically, the energy content of the particulates is not sufficient to sustain the air purifier system 120 in the closed loop mode. An endothermic reaction in the combustion purifier 230 would also not provide any make-up energy to the system. All or some of the supplemental make-up energy may be supplied by fuel that is injected into the combustion purifier 230 using the fuel injector 238.
The air purifier system 120 may also be operated in an open loop mode. Energy for driving the air purifier system 120 in open loop mode may be provided from an external source. For example, the power source 200 may be an electric motor that receives electrical energy from an external source. In another example, a diesel engine may be coupled to the compressor 210 or the turbine 220. A combination of energy produced by an exothermic reaction of particulates, fuel injected into the combustion purifier 230, and/or an external energy source may be used for operation of the air purifier system 120.
An optional screen 240 is disposed in series with the inlet manifold 122. The screen 240 may be disposed before or after one or more of the inlets 112. The screen 240 is configured to pass the particulates while removing larger objects such as debris, pebbles, rocks, insects, small animals, and birds. An optional filter 242 may be disposed in series with the exit manifold 124. When disposed in series with the manifold 124, the filter 242 is configured to remove the particulate residue. The filter 242 may be disposed before or after one or more of the outlets 114. As illustrated in
Referring to
The controller 250 of
The controller 250 may be configured to control a timing of the valve 232, the fuel injector 238, the valve 234, or a combination thereof based data received from the sensors 212, 214, 216, 218, and/or 236. For example, the controller 250 may be coupled to the valve 232 and/or the valve 234 and configured to control opening and closing of these valves. The controller 250 may be coupled to the fuel injector 238 and configured to control timing of the fuel injector 238.
The controller 250 may be coupled to the compressor 210, the power source 200, the turbine 220, or the combustion purifier 230, or any combination of the forgoing. The controller 250 may control output pressure and RPM of the compressor 210. The controller 250 may control RPM of the power source 200 and/or the turbine 220. The controller 250 may control temperature in the combustion purifier 230. For example, the controller 250 may regulate an amount of fuel introduced into the combustion purifier 230 using the fuel injector 238 to control the temperature in the combustion purifier 230.
The controller 250 may include one or more processors. For example, a first processor in the controller 250 may be configured to control valves and injectors such as one or more of valve 232, valve 234, and fuel injector 238, while a second processor in the controller 250 is configured to control the compressor 210. A third processor may be configured to receive data from sensors such as sensors 212, 214, 216, 218, and 236 and communicate the data to the first and/or second processor. Controller 250 can include a processor used to control or receive data in place of two or more of the above described processors.
The combustion chamber 304 of
The conversion of the particulates to a residue may be accomplished by a reduction reaction. Reduction is a process that is used to “unburn” NOx, by burning NOx with other high energy molecules such as HC and CO. The high energy molecules may receive Oxygen from the NOx. In other words, the NOx may burn the HC/CO/PM leaving a residue including N2. The reduction of particulates may be exothermic or endothermic.
The exit chamber 306 of
A thermal conductor 308 may be disposed between the intake chamber 302 and the exit chamber 306. The thermal conductor 308 may be thermally coupled to the exit chamber 306 and the intake chamber 302. The thermal conductor 308 may function as a reverse flow heat exchanger. As the gas flows in opposite directions in contact with the thermal conductor 308, heat from the heated compressed gas in the exit chamber 306 may be transferred to the compressed gas in the intake chamber 302. Thus, heat energy in the heated compressed gas in the exit chamber 306 may be recovered and used to preheat the compressed gas in the intake chamber 302.
A heat source 310 may be used to heat the compressed gas in the combustion chamber 304. The heat source 310 may be an internal heat source or an external heat source. For example, a radiant heat source may be disposed inside or around the outside of the combustion chamber 304. The heat source 310 may include fuel that is injected into the combustion purifier via the fuel injector 238. The fuel may be burned to provide heat using oxygen in the compressed gas. Heat from the heat source 310 may initiate a reaction between the compressed gas and the particulates to convert the particulates to a residue.
A catalyst 312 may be disposed inside the combustion chamber 304 to reduce the combustion temperature or the particulates. The catalyst 312 may catalyze a reaction between the particulates and the gas to enable the reaction to occur at lower temperatures. Other aspects and examples of a combustion purifier are set forth in further detail in U.S. patent application Ser. Nos. 12/271,777; 12/202,186; 11/787,851; 11/800,110; 11/412,289; and 11/404,424, as well as U.S. Pat. No. 7,500,359. The disclosure of each of the aforementioned applications and patent is incorporated herein by reference in its entirety.
The burner manifold 410 may provide a source of make-up energy for sustaining the air purifier system 120 in a closed loop mode, where the closed loop mode involves the compressor 210, the turbine 220, the combustion purifier 230, and the burner manifold 410. The additional or make-up energy provided by the burner manifold 410 may compensate for losses due to inefficiencies in the air purifier system 120.
The burner manifold 410 may receive a portion of the compressed gas via the valve 412 from the compressor 210. An optional one-way valve 402 may be used for maintaining pressure in the burner manifold 410. A fuel injector 416 may receive fuel from a fuel source (not illustrated) and subsequently inject that fuel into the burner manifold 410 for combustion with the compressed gas in the burner manifold 410. The injected fuel may be in the form of solid, liquid, vapor, and/or gas. The fuel and compressed gas may combine in the burner manifold 410 to form a fuel/gas mixture. When the temperature of the compressed gas is at or above the auto ignition temperature of the fuel, the fuel/gas mixture spontaneously combusts to form the combustion gas. The fuel/gas mixture rapidly forms a combustion gas within the burner manifold 410 in the combustion purifier 230. A typical auto ignition temperature for fuels such as diesel is about 800-1700° F. at about 8-16 times ambient pressure.
Alternatively, the compressor 210 may heat the gas to a temperature below the auto ignition temperature for the fuel. Ignition of the fuel/gas mixture can be initiated using a heat source such as a spark or a glow plug. Internal surface features such as baffling, corners, joints, etc., within burner manifold 410 might create local hot spots as a result of uneven flow or turbulence of the fuel/gas mixture. The local hot spots can exceed the auto ignition temperature of the fuel, and initiate ignition of the fuel/gas mixture.
While
Generally, the combustion purifier 230 receives a larger portion of the compressed gas than the burner manifold 410. For example, the burner manifold 410 may be configured to provide sufficient energy to drive the turbine 220 and the compressor 210 using a negligible portion of the compressed air. The combustion purifier 230 may convert particulates in the rest of the compressed air to residue and provide a negligible portion of the energy. The combustion purifier 230 may also receive fuel via the fuel injector 238 for promoting and/or sustaining combustion of the particulates within the combustion purifier 230.
The sensor 418 may be coupled to the controller 250 via the control coupling 252. The sensor 418 includes one or more components configured to sense parameters relating to the burner manifold 410 such as pressure, temperature, volume, flow, and velocity. The controller 250 may be coupled to the fuel injector 416, the valve 412, and/or the valve 414 via the control coupling 252. The controller 250 may adjust a flow and/or pressure of compressed gas entering the burner manifold 410 using the valve 412. The controller may adjust a flow and/or amount of combustion gas exiting the burner manifold 410 using the valve 414. The controller 250 may adjust a ratio of compressed gas entering the burner manifold 410 to the compressed gas entering the combustion purifier 230. The controller 250 may adjust an amount of fuel entering the burner manifold 410 using the fuel injector 416. The controller 250 may control a temperature in the burner manifold 410. For example, the controller 250 may regulate the amount of fuel introduced into the burner manifold 410 using the fuel injector 416.
The combustion gas formed in the burner manifold 410 is provided to the turbine 220 and used to drive the turbine 220. The turbine 220 in turn is used to drive the compressor 210. Energy stored in the fuel is released by combustion of the fuel in the burner manifold 410. The released energy is used to compensate for energy lost in system components such as the compressor 210, the combustion purifier 230, and the turbine 220. Combustion gas from both the combustion purifier 230 and the burner manifold 410 may be used to drive the turbine 220.
The energy from the fuel may increase the temperature and/or velocity of molecules of the combustion gas. While the pressure of the combustion gas exiting the burner manifold 410 may be lower than the pressure of the compressed gas entering the burner manifold 410, the energy content of the combustion gas, represented by temperature and/or velocity of the combustion gas, is higher than the compressed gas. The increased temperature and/or velocity of the molecules in the combustion gas may be used to drive the turbine 220.
The controller 250 may adjust the fuel injector 416 to meter the fuel injected into the burner manifold 410 for a relatively lean or a relatively rich fuel/gas mixture. A lean mixture generally results in complete combustion of the fuel in the presence of excess oxygen. Combustion of the fuel in the burner manifold 410 may be used to raise the temperature of the combustion gas to the combustion temperature of the particulates while leaving residual oxygen in the combustion gas. The combustion gas, including the residual oxygen, from the burner manifold 410 is then provided to the combustion purifier 230. The residual oxygen is used in the combustion purifier 230 for oxidation of the particulates to a residue.
A rich mixture generally results in complete depletion of the oxygen in the compressed gas upon combustion of the fuel with the gas. The oxygen depleted gas may be provided to the combustion purifier 230 and used for reducing the particulates. A fuel having a combustion temperature that is less than the combustion temperature of the particulates in the gas can be used. The particulates can then be reduced in the combustion purifier 230 at a temperature below the combustion temperature of the particulates.
The heated combustion gas formed in the burner manifold 410 is provided to the combustion purifier 230 for conversion of the particulates to a residue. The combustion purifier 230 may receive fuel via the fuel injector 238 for promoting and/or sustaining combustion of the particulates. Heated combustion gas from the combustion purifier 230 is used for driving the turbine 220 which in turn is coupled to the compressor 210 and used for driving the compressor 210 as discussed elsewhere herein.
The controller 250 may control temperatures in the burner manifold 410. For example, the controller 250 may adjust the fuel injector 416 regulate an amount of fuel and the valve 412 to regulate an compressed air introduced into the burner manifold 410. The regulation of the fuel injector 416 and the valve 412 may be based on the temperature in the combustion purifier 230 sensed using the sensor 236. Similarly, the controller 250 may regulate a temperature in the combustion purifier 230 using the fuel injector 238 and the valve 232 based on a temperature sensed in the burner manifold 410 using the sensor 418.
The controller 250 may adjust the fuel/gas mixture for a rich or lean mixture to control the temperature of the combustion gas. For example, the temperature of the combustion gas generally increases as a rich fuel/gas mixture is leaned, either by adding more gas or less fuel. The temperature of the combustion gas reaches a maximum and then decreases as the mixture is leaned further.
The burner manifold 410 of
The combustion purifier 230 may be disposed, however, between the compressor 210 and the burner manifold 410. The intake chamber 302 of the combustion purifier 230 may be configured to receive compressed gas from the compressor 210, and the exit chamber 306 of the combustion purifier 230 may be configured to provide the compressed gas to the burner manifold 410. In such a configuration, the particulates are converted to residue in the combustion purifier 230 before the compressed gas is provided to the burner manifold 410 for heating. The burner manifold 410 can then further heat the compressed air and residue to a temperature well above an operating temperature range of the catalyst 312 in the combustion purifier 230 without damaging the catalyst 312. The burner manifold 410 in turn provides the heated compressed gas to the turbine 220 for driving the compressor 210 as discussed elsewhere herein.
The reservoir 600 may be insulated to maintain the temperature of the compressed gas in the reservoir 600. A heater (not shown) may be disposed in or around the reservoir to heat the compressed gas to make up for heat lost during storage. The compressed gas in the reservoir 600 may be used for starting the turbine 220 or keeping it running when heated compressed gas is not available from the combustion purifier 230. The compressed gas may be provided from the reservoir 600 to the burner manifold 410 via valves 602 and 412, for example, when the compressor 210 is not running. The valves 602 and/or 604 may be used as one-way valves for maintaining storage of the compressed gas in the reservoir 600.
The reservoir 600 is illustrated in
The controller 250 may adjust the valves 602 and 604 to regulate an amount and/or pressure of compressed gas in the reservoir 600 based on pressure and/or temperature in the reservoir 600 sensed using the sensor 606. The controller 250 may adjust the amount and/or pressure of the compressed gas in the reservoir 600 based on pressure and/or temperature in the burner manifold 410 sensed using the sensor 418. Similarly, the controller 250 may adjust the amount and/or pressure of the compressed gas in the reservoir 600 based on pressure and/or temperature in the combustion purifier 230 sensed using the sensor 236.
The compressor 712 may receive compressed gas at the first pressure from the compressor 210 and further compress the gas to a second pressure. If the second pressure is about 4-5 times the first pressure then the second pressure may be about 12-20 times the ambient pressure of gas at the inlet manifold 122. The valve 402 may control a volume and flow of gas to the compressor 712. The valve 402 may be a one way valve. An optional intercooler (not illustrated) may be disposed between the compressor 210 and the compressor 712 to cool the compressed gas received by the compressor 712. Similar to compressor 210, the compressor 712 may be driven using a power source 200. The screen 240 and the filter 242 have been omitted for clarity.
Alternatively, the compressor 712 may also receive gas at ambient pressure from the inlet manifold 122 (not illustrated) instead of from the compressor 210. The compressor 210 may compress the gas to a first pressure for the combustion purifier 230. The compressor 712 may compress the gas to a second pressure for the burner manifold 410. The first pressure may be independent of the second pressure. Thus, the combustion purifier 230 may receive compressed gas at a first pressure and temperature that is optimized for converting particulates to residue. The burner manifold 410 may receive compressed gas at a second pressure and temperature that is optimized for combustion of fuel to efficiently drive a turbine.
The controller 250 of
The controller 250 may control the first pressure and temperature of the compressed gas independently of the second pressure and temperature of the compressed gas. For example, the controller 250 may control the compressor 210 and the valve 232 to adjust the first pressure and temperature of the compressed gas received by the combustion purifier 230. The controller 250 may independently control the compressor 712, the valve 402, and the valve 412 to adjust the second pressure and temperature of the compressed gas received by the burner manifold 410.
While a two stage compressor system is illustrated in
In step 1010, particles in the compressed gas may be heated to a second temperature in the reverse flow combustion purifier. The compressed gas and particles may be received from the compressor. Alternatively, the compressed gas and particles are received from the burner manifold. The compressed gas and particles may be received from the burner manifold and the compressor. The second temperature may be a combustion temperature of the particles. In step 1012, a particle residue is produced from combustion of the heated particles in the reverse flow combustion purifier 230. In step 1014, the heated compressed gas from the reverse flow combustion purifier is provided to the turbine. In step 1016, power is generated by driving the turbine using the heated compressed gas. In step 1018, the power generated by the turbine is provided to the compressor. The power provided to the compressor is used to compress the gas.
Several embodiments are specifically illustrated and/or described herein. However, it will be appreciated that modifications and variations are covered by the above teachings and within the scope of the appended claims without departing from the spirit and intended scope thereof. For example, swarms of insects may be ingested by the air cleaning system 100 and oxidized to provide make-up energy to run the system. The air cleaning system 100 may be used to remove pollutants from gases emitted by smoke stacks at industrial installations. The air cleaning system 100 may be used to render toxic gases inert. The air cleaning system 100 may be used to convert carbon monoxide to carbon dioxide in tunnels and mines. Various embodiments of the invention include logic stored on computer readable media, the logic configured to perform methods of the invention.
The embodiments discussed herein are illustrative of the present invention. As these embodiments of the present invention are described with reference to illustrations, various modifications or adaptations of the methods and/or specific structures described may become apparent to those skilled in the art. All such modifications, adaptations, or variations that rely upon the teachings of the present invention, and through which these teachings have advanced the art, are considered to be within the spirit and scope of the present invention. Hence, these descriptions and drawings should not be considered in a limiting sense, as it is understood that the present invention is in no way limited to only the embodiments illustrated.
The present application is a continuation in part and claims the priority and benefit of U.S. patent application Ser. No. 12/332,312, filed on Dec. 10, 2008, and entitled “External Compression Two-Stroke Internal Combustion Engine with Burner Manifold,” which is a continuation in part of U.S. patent application Ser. No. 12/252,779, filed on Oct. 16, 2008, and entitled “External Compression Two-Stroke Internal Combustion Engine.” The disclosures of all of the above U.S. patent applications are incorporated by reference herein in their entirety.
Number | Date | Country | |
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Parent | 12332312 | Dec 2008 | US |
Child | 12538761 | US | |
Parent | 12252779 | Oct 2008 | US |
Child | 12332312 | US |