POWER SYSTEM HAVING ADDITIVE INJECTOR

- Caterpillar Inc.

A power system is provided. The power system includes a power source configured to generate a flow of exhaust including particulate matter. The power system also includes a fuel supply line connecting a fuel supply and the power source, and being configured to direct a fuel flow from the fuel supply to the power source. An additive injector is configured to inject an additive into the fuel flow. An ionization device is at least partially disposed within the flow of exhaust, and is configured to apply a charge to the particulate matter and the additive. A particulate filter is configured to remove the particulate matter and the additive from the flow of exhaust.

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Description
TECHNICAL FIELD

The present disclosure relates generally to a power system and, more particularly, to a power system having an additive injector.

BACKGROUND

Internal combustion engines, including diesel engines, exhaust a complex mixture of potential air pollutants. These air pollutants may include solid material known as particulate matter or soot. Due to increased environmental concerns, diesel engine exhaust emission standards have become more stringent. The amount of particulate matter emitted from an engine may be regulated depending on the type of engine, size of engine, and/or class of engine.

One method implemented by engine manufacturers to comply with the regulation of particulate matter exhausted to the environment has been to remove the particulate matter from the exhaust flow of an engine using a particulate matter collection device, for example, a particulate trap or diesel particulate filter (DPF). A DPF is a filter designed to trap particulate matter in a filter substrate, which may include, for example, wire mesh or ceramic honeycomb filtering media. Though effective in reducing relatively larger-sized particulate matter from the exhaust, the filtering media may not be efficient in trapping relatively smaller-sized particulate matter.

Over time, the particulate matter may accumulate on the filtering media, and may block the exhaust passageway, thereby increasing pressure in the exhaust, and reducing engine performance. The DPF can be regenerated by raising the temperature of the exhaust, for example, through controlling the engine combustion or a heating device associated with the DPF, to burn off the particulate matter attached to the filter media. Typically, a DPF regeneration process lasts for a predetermined period of time, for example, 10 minutes. In some cases, when the distribution of the particulate matter on the filtering media is not uniform, some particulate matter may remain unburned by the time the regeneration process is terminated.

Various regeneration techniques may be employed to manage the reduction of the particulate matter in engine exhaust. For example, U.S. Pat. No. 6,488,725 (“the '725 patent”) issued to Vincent et al. on Dec. 3, 2002, describes a method of supplying an iron-containing fuel soluble additive for use in the regeneration of a particulate filter trap. The method includes adding an additive to the fuel prior to or during combustion. In particular, the supply of additive is added to the fuel at any stage in the fuel supply chain, or is added via a dosing device on-board the vehicle to either the fuel, or directly into the combustion chamber or the inlet system. The additive mixes with the fuel, and the mixture is combusted to provide a flow of exhaust containing soot particulates and additives. In operation, the additives reduce the soot particulate ignition temperature.

Although the method described in the '725 patent may suitably regenerate the particulate filter trap, it may be problematic. For example, if the particulate matter is sufficiently fine in size, the diesel particulate filter may not be efficient in trapping the fine particulate matter. Thus, the fine particulate matter may be discharged directly into the environment, causing pollution to the environment. Furthermore, the distribution of the particulate matter and additives on the filter media may not be uniform. This may result in residual particulate matter remaining unburned on the filtering media after the regeneration is terminated, which may adversely affect the exhaust flow and/or the engine performance.

The system of the present disclosure is directed toward improvements in the existing technology.

SUMMARY

One aspect of the present disclosure is directed to a power system. The power system includes a power source configured to generate a flow of exhaust. The power system also includes a fuel supply line connecting a fuel supply and the power source. The fuel supply line is configured to direct a fuel flow from the fuel supply to the power source. An additive injector is configured to inject an additive into the fuel flow. An ionization device is at least partially disposed within the flow of exhaust, and configured to apply a charge to the additive and particulate matter within the flow of exhaust. A particulate filter is configured to remove the particulate matter and the additive from the flow of exhaust.

Another aspect of the present disclosure is directed to a method of removing particulate matter from a flow of exhaust. The method includes directing a flow of fuel into a power source. The method also includes injecting an additive into the flow of fuel upstream of the power source. The method also includes combusting the fuel and the additive to produce a flow of exhaust having particulate matter and additive. The method also includes applying a charge to the additive and particulate matter by directing the flow of exhaust through an ionization device. The method further includes directing the flow of exhaust through a particulate filter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic and diagrammatic illustration of an exemplary machine having an exemplary disclosed power system.

DETAILED DESCRIPTION

FIG. 1 schematically illustrates an exemplary machine 5, in which an exemplary disclosed power system 10 may be employed. Machine 5 may be any type of machine, for example, a mobile machine, such as a passenger vehicle, a vocational vehicle, a farming machine, a mining machine, a construction machine, etc. Alternatively, machine 5 may be a stationary machine such as, for example, a power generation machine.

Power system 10 may include a power source 20 configured to combust fuel and generate a flow of exhaust including particulate matter, and an exhaust after-treatment system 30 configured to treat the flow of exhaust. For the purposes of this disclosure, power source 20 is depicted and described as a four-stroke diesel engine. One skilled in the art will recognize that power source 20 may be any type of internal combustion engine such as, for example, a gasoline engine, a gaseous fuel-powered engine (e.g., a natural gas engine), or any other type of combustion engine known to one skilled in the art. Power source 20 may include an engine block that at least partially defines a plurality of combustion chambers 25. In the illustrated embodiment, power source 20 includes four combustion chambers. It is contemplated that power source 20 may include a greater or lesser number of combustion chambers 25 and that the combustion chambers 25 may be disposed in an “in-line” configuration, or a “V” configuration, or any other suitable configuration.

Power source 20 may draw an air/fuel mixture into each one of combustion chambers 25 to produce combustion and generate power, heat, and exhaust. In particular, power source 20 may include an intake manifold 35 to supply the air/fuel mixture to power source 20. Intake manifold 35 may receive fuel from a fuel system 40 and air from an air supply system (not shown), and may direct a mixture of the air and fuel to each of combustion chambers 25.

Fuel system 40 may be configured to deliver fuel to power source 20 for combustion. Fuel system 40 may include a fuel supply 45, a pump 55, and a fuel supply line 50 configured to direct a fuel flow from fuel supply 45 to power source 20. Fuel supply line 50 may be configured to direct a fuel flow from fuel supply 45 to intake manifold 35 of power source 20. Pump 55 may be disposed within fuel supply line 50, and may be configured to draw an amount of fuel from fuel supply 45, pressurize the fuel, and direct the pressurized fuel to intake manifold 35. Alternatively, it is contemplated that power source 20 may include an injector (not shown) associated with each of combustion chambers 25 and being configured to inject fuel into each of combustion chambers 25.

Power system 10 may further include devices that provide a supply of additive solution to the fuel flow prior to or during combustion. Specifically, power system 10 may include an additive supply 60 configured to store and supply an amount of additive, and an additive injector 70 configured to inject additive into the fuel flow supplied to power source 20. Power system 10 may also include a pump 65 configured to pump the additive from additive supply 60 to additive injector 70. Pump 65 may be any kind of high-precision, metered, low-flow rate pump. Pump 65 may be a diaphragm pump or any other pump known in the art. Additive injector 70 may be disposed at any suitable location within power system 10. For example, additive injector 70 may be disposed at least partially within fuel supply line 50, at least partially within fuel supply 45, adjacent intake manifold 35, or adjacent combustion chambers 25. Additive may be injected by additive injector 70 into the fuel supplied to power source 20. For example, additive may be injected into fuel supply line 50, fuel supply 45, intake manifold 35, combustion chambers 25, or any suitable location within fuel system 40 or power source 20 prior to or during combustion. As illustrated in FIG. 1, additive injector 70 may be located upstream of power source 20, and may inject the additive into intake manifold 35 upstream of power source 20. It is contemplated that additive injector 70 may be mechanically, hydraulically, or electrically actuated.

After-treatment system 30 may be configured to reduce emissions of harmful gases and particulate matter emitted from power source 20 after a combustion process. After-treatment system 30 may include an exhaust manifold 85 having exhaust passageways, each passageway being in fluid communication with one of combustion chambers 25. After-treatment system 30 may include a passageway 90, which may be in fluid communication with exhaust manifold 85. After-treatment system 30 may include various devices within passageway 90 to reduce harmful gases and particulate matter from the exhaust. For example, after-treatment system 30 may include a particulate filter 95 at least partially disposed within passageway 90, and being configured to trap particulate matter as the exhaust passes therethrough. Although not shown, one skilled in the art may recognize that after-treatment system 30 may also include a fuel-fired burner or a heating device associated with particulate filter 95 for increasing the temperature of the exhaust or the particulate matter trapped within particulate filter 95 to oxidize the particulate matter during a regeneration process. In some embodiments, the temperature of the exhaust may be increased through control of the engine combustion. In such embodiments, no fuel-fired burner or heating device may be included in after-treatment system 30. It is contemplated that after-treatment system 30 may include other components known in the art, such as, for example, a selective catalytic reductant device, a NOx trap, a SOx reduction device, etc.

Particulate filter 95 may be any variety of particulate filter, such as, for example, a sintered metal fiber flow-through filter, cordierite or silicon carbide wall-flow filter, or any other particulate filter known in the art. Particulate filter 95 may include a housing 100 and a filter substrate 105 disposed at least partially within housing 100. Filter substrate 105 may include a wire mesh medium, a ceramic honeycomb filtration medium, or any other suitable medium known in the art. As the flow of the exhaust passes through the filtration medium, the particulate matter, for example, unburned hydrocarbons, may impinge against and be blocked by the filtration medium. Over time, the particulate matter may build up on the surfaces of filter substrate 105 and the filtration medium may become saturated. This build-up of the particulate matter may reduce the flow of exhaust through particulate filter 95 and may adversely affect the engine performance.

Power system 10 may include a control system 120 configured to control the operation of power system 10. Control system 120 may include a controller 80, which may be an existing machine control module or a stand-alone controller. Controller 80 may be associated with various systems and devices of power system 10. For example, controller 80 may be associated with at least one of power source 20, after-treatment system 30, and fuel system 40. Controller 80 may control operations of power source 20, exhaust after-treatment, and fuel delivery. For another example, controller 80 may also be associated with at least one of additive supply 60, additive injector 70, and pump 65. Controller 80 may be configured to control the injection of the additive into the fuel supplied to power source 20. Controller 80 may regulate the amount and the timing of the injection of additive through controlling at least one of additive supply 60, additive injector 70, and pump 65.

Control system 120 may include at least one sensor in fluid communication with the flow of exhaust and being configured to measure a parameter of the flow of exhaust. Control system 120 may also include at least one sensor associated with particulate filter 95 and being configured to measure a parameter of particulate filter 95. For example, control system 120 may include a temperature sensor 130. Temperature sensor 130 may be at least partially disposed within passageway 90, for example, upstream or downstream of particulate filter 95, and may be in fluid communication with the flow of exhaust. Temperature sensor 130 may measure a temperature of the flow of exhaust, and may generate a signal indicative of the measured temperature. Temperature sensor 130 may send the signal to controller 80 for analysis. In some embodiments, temperature sensor 130 may also be configured to measure a temperature associated with particulate filter 95 or a temperature of the particulate matter accumulated on the surfaces of filter substrate 105. Temperature sensor 130 may be integral with a part of particulate filter 95, for example, filter substrate 105, or may be disposed adjacent particulate filter 95.

Control system 120 may include a pressure sensor 135 at least partially disposed within passageway 90, and being in fluid communication with the flow of exhaust. Pressure sensor 135 may be configured to measure a pressure of the exhaust within passageway 90. For example, pressure sensor 135 may be disposed upstream of particulate filter 95 to monitor a pressure of the exhaust upstream of particulate filter 95. Pressure sensor 135 may also be disposed downstream of particulate filter 95, if desired. It is contemplated that more than one pressure sensor may be located at various locations within passageway 90.

Control system 120 may also include a particulate filter load sensor 125 configured to measure a load of the particulate matter within particulate filter 95, for example, an amount of the particulate matter accumulated on the surfaces of filter substrate 105. Load sensor 125 may generate a signal indicative of the load of the particulate matter, and may send the signal to controller 80. Load sensor 125 may be integrated with or disposed adjacent particulate filter 95.

Additionally and/or alternatively, at least one of the temperature of the exhaust or particulate filter 95, the pressure of the exhaust within passageway 90, and the load of particulate filter 95, may be estimated by controller 80 rather than be measured by sensors. That is, controller 80 may determine the temperature, pressure, and load associated with the exhaust and/or particulate filter 95 as a function of variables related to one or more operating conditions of power source 20 and/or the machine associated therewith (i.e., virtual sensors). For example, one or more engine performance maps relating a fueling amount, ignition timing, power output, engine speed, boost pressure, engine temperature, an air/fuel ratio, and/or other known parameters may be stored within a memory of controller 80. Each of these maps may be in the form of tables, graphs and/or equations and may include a compilation of data collected from lab and/or field operation of power source 20. Controller 80 may receive data relating to the operation of power system 10 and may reference one or more of these maps in order to estimate a temperature, pressure, and load associated with the exhaust and/or particulate filter 95 for a given operating condition of power source 20. In this manner, controller 80 may measure or estimate temperature data from which decisions about the regeneration of particulate filter 95 and the injection of the additive may be made.

After-treatment system 30 may include an ionization device 140. Ionization device 140 may be at least partially disposed within exhaust passageway 90 upstream of particulate filter 95. Ionization device 140 may be connected with a first charging device 145 configured to supply a voltage of a predetermined polarity, such as a positive voltage, to ionization device 140. As a result, ionization device 140 may become charged, and may in turn apply a first charge, for example, a positive charge, to the particulate matter and the additive particles within the exhaust as the exhaust passes by ionization device 140. Thus, the particulate matter and the additive particles may become electrostatically charged with a like charge, for example, the positive charge.

After-treatment system 30 may also include a second charging device 155 configured to apply a second charge to particulate filter 95. The second charge may have a polarity opposite to that of the first charge applied to the particulate matter and the additive particles. Second charging device 155 may be connected with a suitable portion of particulate filter 95, for example, filter substrate 105 or housing 100. Second charging device 155 may supply a voltage to, for example, filter substrate 105 of particulate filter 95, such that filter substrate 105 of particulate filter 95 may be electrostatically charged with the second charge.

At least one of the first and second charging devices 145 and 155 may be connected with and controlled by controller 80. Controller 80 may control, for example, the magnitude and polarity of voltages supplied to ionization device 140 and particulate filter 95 by controlling first and second charging devices 145 and 155, respectively. In other words, controller 80 may control the amounts and polarity of charges applied to the particulate matter and additive particles, and particulate filter 95. Although shown as separate devices, in some embodiments, at least one of first and second charging devices 145 and 155 may be integral with controller 80.

INDUSTRIAL APPLICABILITY

The disclosed system may be applicable to any power system for reducing the particulate matter generated from combustion and for facilitating regeneration of a particulate filter. For example, the disclosed after-treatment system 30 may be applicable to mobile systems, such as engines that power mobile vehicles, for example, automobiles, semi-trailer trucks, construction equipment, marine vessels, etc. After-treatment system 30 may also be applicable to stationary machines, such as electric power generation sets.

Power source 20 may combust a mixture of air and fuel to generate power and exhaust. Fuel system 40 may supply fuel to power source 20. Pump 55 may draw fuel from fuel supply 45, pressurize the fuel, and direct the pressurized fuel to intake manifold 35. The fuel may be mixed with air received from an air supply system (not shown), and may be directed into combustion chambers 25 for combustion therein. Power source 20 may output, after combustion, a flow of exhaust. The flow of exhaust may be discharged from combustion chambers 25, and directed through exhaust manifold 85 to after-treatment system 30, where the exhaust is treated. The flow of exhaust may contain a complex mixture of air pollutants, which may include particulate matter. The release of particulate matter into the environment may be reduced by passing the flow of exhaust through particulate filter 95.

Additive may be injected into the fuel flow supplied to power source 20 at a suitable location within power system 10 prior to or during combustion. The additive may be configured for the purpose of facilitating the regeneration of particulate filter 95, for the purpose of improving uniform distribution of the particulate matter on the surfaces of filter substrate 105, or for other suitable purposes. The additive may be an iron-based material, for example, Dicyclopentadienyl iron, or any other suitable materials. Additive injector 70 may inject a predetermined amount of additive into the fuel flow supplied to power source 20. Alternatively, additive injector 70 may inject the additive into intake manifold 35 or combustion chambers 25. The additive may be combusted together with the air/fuel mixture within combustion chambers 25.

After combustion, the additive may become particles and may be present within the exhaust together with the particulate matter. As the exhaust passes by ionization device 140, ionization device 140 may apply an electrical charge, such as, for example, a positive electrical charge, to the additive particles and the particulate matter. Controller 80 may control ionization device 140 by controlling the voltage supplied from first charging device 145 to ionization device 140. As a result, the additive particles and the particulate matter may become electrostatically charged with like charges of the same polarity, for example, the positive polarity.

The charged additive particles and the particulate matter may repel one another due to the electrostatic force between two charges with the same polarity. Specifically, the repelling force may exist between any charged additive particles and any charged particles of the particulate matter. As a result of the repelling force, a uniform distribution of the particulate matter and/or the additive particles within the exhaust may be created. Consequently, when the particulate matter and/or the additive particles attach to the surfaces of filter substrate 105, a uniform distribution of the particulate matter and/or the additive particles on the surfaces of filter substrate 105 may be achieved. Uniform distribution of the particulate matter and the additive particles may improve the efficiency of the regeneration of the particulate matter, reducing or eliminating residual particulate matter remaining on filter substrate 105 when a regeneration process is terminated.

Controller 80 may control second charging device 155 to apply a counter voltage to a portion of particulate filter 95, for example, filter substrate 105. In other words, for example, when a positive voltage is supplied to ionization device 140, a negative voltage may be supplied to filter substrate 105. Therefore, when the positively charged particulate matter and the additive particles arrive at filter substrate 105, the positively charged particulate matter and the additive particles may be attracted to the surfaces of negatively charged filter substrate 105 due to the electrostatic attraction force between the opposite electrical charges. In such a way, the particulate matter may be better captured by filter substrate 105. In particular, smaller-sized particulate matter, which may otherwise escape through the meshes of filter substrate 105 when not electrostatically charged, may be captured by filter substrate 105 due to the electrostatic attraction force between the positively charged particulate matter and the negatively charged filter substrate 105.

Controller 80 may control the regeneration of particulate filter 95, and/or the injection of the additive. For example, during the operation of power system 10, controller 80 may monitor the load of particulate matter accumulated on filter substrate 105 by load sensor 125. When load sensor 125 indicates that the particulate matter load of filter substrate 105 exceeds a predetermined load threshold, controller 80 may activate a regeneration process to regenerate particulate filter 95. Alternatively and/or additionally, controller 80 may monitor the pressure of the exhaust flow upstream of particulate filter 95 through pressure sensor 135, which may generate a signal indicative of the pressure of the exhaust flow and send the signal to controller 80. Controller 80 may determine, based on the measured pressure of the exhaust flow, whether a regeneration process is needed to regenerate particulate filter 95. It is contemplated that controller 80 may also determine whether a regeneration is needed to regenerate particulate filter 95 based on the temperature of the exhaust flow and/or the particulate matter captured by filter substrate 105, as measured by temperature sensor 130. Controller 80 may activate a regeneration based on at least one of the load measured by load sensor 125, the pressure measured by pressure sensor 135, and the temperature measured by temperature sensor 130.

Controller 80 may monitor the temperature of the exhaust flow, and/or the temperature associated with particulate filter 95, through temperature sensor 130. Temperature sensor 130 may generate a signal indicative of the measured temperature and send the signal to controller 80. In one embodiment, after determining that a regeneration process is needed to regenerate particulate filter 95, controller 80 may determine, based on at least one of the load measured by load sensor 125, the temperature measured by temperature sensor 130, and the pressure measured by pressure sensor 135, the amount of the additive to be injected by additive injector 70 and the timing to inject the additive.

For example, controller 80 may determine the amount and timing of the injection of the additive based on the load measured by the load sensor 125. After controller 80 receives the signal generated by load sensor 125, and determines that a regeneration is needed, controller 80 may activate additive injector 70 and pump 65 to inject a predetermined amount of additive into the fuel flow supplied to power source 20.

For another example, when controller 80 receives the temperature signal generated by temperature sensor 130, and determines that the temperature of the exhaust or particulate filter 95 has reached a predetermined temperature threshold, controller 80 may activate pump 65 and/or additive injector 70 to inject a predetermine amount of additive into the fuel flow supplied to power source 20.

For another example, when controller 80 receives the signal generated by pressure sensor 135 and determines that the pressure of the exhaust has exceeded a predetermined threshold, controller 80 may activate pump 65 and/or additive injector 70 to inject a predetermined amount of additive into the fuel flow supplied to power source 20. When additive is injected, controller 80 may control additive injector 70 to inject the additive continuously for a predetermined amount of time, or to inject a predetermined amount of additive for a predetermined time interval, for example, 30 seconds. The injection of the additive may be terminated by controller 80 when regeneration is terminated, or at any desired suitable time. For example, controller 80 may determine when to terminate the injection of the additive based on at least one of the pressure measured by pressure sensor 135, temperature measured by temperature sensor 130, and load measured by load sensor 125.

During a regeneration of particulate filter 95, controller 80 may control the combustion within combustion chambers 25 and/or a fuel-fired burner (not shown) or a heating device (not shown) associated with particulate filter 95 to increase the temperature of the exhaust and/or the particulate matter captured by filter substrate 105 in order to oxidize the particulate matter. As the temperature is increased to an oxidization temperature range, for example, 500-600° C., the particulate matter may become oxidized. At filter substrate 105, the additive may undergo a chemical reaction, which may catalyze oxidization of the particulate matter. For example, iron-based additive may lower the ignition or oxidization threshold temperature of the particulate matter, thereby enabling oxidization of the particulate matter at a relatively low temperature, and thus, facilitating the regeneration of particulate filter 95.

In some embodiments, because the additive may lower the temperature required to oxidize or ignite the particulate matter, the effort required to increase the temperature of the exhaust or the temperature associated with particulate filter 95 through intentionally controlling combustion in power source 20, or through operating a fuel-fired burner, or by controlling a heating device may be significantly reduced.

A regeneration process may last for a predetermined period of time, for example, 10 minutes. During the regeneration process, particulate matter accumulated on filter substrate 105 may be burned off from the surfaces of filter substrate 105. Because of the expelling force existing between the charged exhaust including particulate matter and/or additives, the particulate matter may be more uniformly distributed on the surfaces of filter substrate 105. As a result, during the regeneration process, the particulate matter accumulated on the surfaces of filter substrate 105 may be uniformly burned. After the particulate matter is burned, at least some additive particles may be separated from the surfaces of filter substrate 105, and may be stored in housing 100. The additive particles may later be collected for disposal or recycling, for example, during regular maintenance of particulate filter 95.

It will be apparent to those skilled in the art that various modifications and variations can be made to the power system of the present disclosure without departing from the scope of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the system disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.

Claims

1. A power system, comprising:

a power source configured to generate a flow of exhaust including particulate matter;
a fuel supply line connecting a fuel supply and the power source, and being configured to direct a fuel flow from the fuel supply to the power source;
an additive injector configured to inject an additive into the fuel flow;
an ionization device at least partially disposed within the flow of exhaust, and being configured to apply a charge to the particulate matter and the additive; and
a particulate filter configured to remove the particulate matter and the additive from the flow of exhaust.

2. The power system of claim 1, wherein the additive injector is located upstream of the power source.

3. The power system of claim 1, further including:

an additive supply; and
a pump configured to draw the additive from the additive supply and direct the additive to the additive injector.

4. The power system of claim 1, wherein the additive is an iron-based additive.

5. The power system of claim 1, further including a sensor in fluid communication with the flow of exhaust and being configured to measure a parameter of the flow of exhaust.

6. The power system of claim 5, wherein the sensor includes at least one of a temperature sensor or a pressure sensor, and the parameter is at least a temperature of the flow of exhaust or a pressure of the flow of exhaust.

7. The power system of claim 1, further including a load sensor associated with the particulate filter and being configured to measure a load of the particulate matter.

8. The power system of claim 1, further including a first charging device associated with the ionization device and being configured to provide the charge applied to the particulate matter and the additive.

9. The power system of claim 8, wherein the charge applied to the particulate matter and the additive is a first charge, the power system further including a second charging device associated with the particulate filter, and being configured to apply a second charge to the particulate filter.

10. The power system of claim 9, further including a controller associated with the additive injector and being configured to control the injection of the additive into the fuel flow.

11. The power system of claim 10, wherein the controller is further configured to control the first and second charges.

12. A method of removing particulate matter from a flow of exhaust, comprising:

directing a flow of fuel into a power source;
injecting an additive into the flow of fuel;
combusting the fuel to produce the flow of exhaust, wherein the flow of exhaust includes the particulate matter and the additive;
applying a like charge to the particulate matter and the additive; and
directing the flow of exhaust through a particulate filter.

13. The method of claim 12, further including controlling the injection of the additive based on a parameter associated with the flow of exhaust.

14. The method of claim 13, wherein the parameter is indicative of at least one of a temperature of the flow of exhaust and a pressure of the flow of exhaust.

15. The method of claim 12, further including controlling the injection of the additive based on a load of the particulate matter within the particulate filter.

16. The method of claim 12, further including applying a charge to the particulate filter, the charge applied to the particulate filter having a polarity opposite to the polarity of the like charge applied to the particulate matter and the additive.

17. A machine, comprising:

a power source configured to combust fuel and generate a flow of exhaust including particulate matter;
a fuel supply line configured to direct a fuel flow from a fuel supply to the power source;
an additive injector configured to inject an additive into the fuel flow;
an ionization device at least partially disposed within the flow of exhaust, and being configured to apply a first charge having a first polarity to the particulate matter and the additive;
a particulate filter configured to remove the particulate matter and the additive from the flow of exhaust; and
a charging device configured to apply a second charge to the particulate filter, the second charge having a second polarity opposite to the first polarity.

18. The machine of claim 17, wherein the additive injector is located upstream of the power source.

19. The machine of claim 17, wherein the additive is an iron-based additive.

20. The machine of claim 17, further including:

at least one sensor in fluid communication with the flow of exhaust and being configured to measure a parameter of the flow of exhaust;
at least one sensor associated with the particulate filter and being configured to measure a parameter of the particulate filter; and
a controller associated with the additive injector and being configured to control the injection of the additive into the fuel flow based on at least one of the parameter of the flow of exhaust and the parameter of the particulate filter.
Patent History
Publication number: 20110146234
Type: Application
Filed: Dec 23, 2009
Publication Date: Jun 23, 2011
Applicant: Caterpillar Inc. (Peoria, IL)
Inventors: Christopher J. Rynders, JR. (Peoria, IL), Clifford Eugene Cotton, III (Bradford, IL), Brett Bailey (Effingham, SC)
Application Number: 12/645,566
Classifications
Current U.S. Class: Anti-pollution (60/274); By Electrolysis, Electrical Discharge, Electrical Field, Or Vibration Generator (60/275)
International Classification: F01N 3/01 (20060101);