Patent Application
20080092525
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself however, as well as a preferred mode of use, further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
Turning to the Figures where like reference numerals refer to like structures, the present invention relates to a method and apparatus for cleaning ash from a diesel particulate filter 20 which can be used while the diesel particulate filter 20 still attached to the motor vehicle 11 or truck, such as to the chassis, or used after removal of the diesel particulate filter 20 and housing 22. The filter apparatus 10 can be installed on the motor vehicle 11 is any configuration, such as vertically, horizontally or under the cab.
The engine 12 is in fluid communication with the filter apparatus 10 through entrance tubing 14 at the inlet side of the filter apparatus 10. Treated exhaust flows from the filter apparatus 10 through exit tubing 16, which can include a tailpipe, at the outlet side of the filter apparatus 10.
As shown in
The first conduit 24 has a first port 28. An inflatable first bladder 30 is located within the first conduit 24 and is accessible through the first port 28. When inflated by pumping gas or air through the stem 31, the first bladder 30 closes off the housing from the catalytic device 18.
Pressure waves can be generated at the exit tubing 16 or second conduit 26 and transmitted into the housing 22. After inflating the bladder 30, pulses of compressed gas can be directed through the exit tubing 16 or second conduit into the housing 22. The pulses of compressed gas dislodge the ash particles from the diesel particulate filter 20. An ash collecting apparatus 84, such as a shop vacuum, can be inserted into the first port 28 to remove the dislodged ash particles.
A second port 32 can be located between the housing 22 and an exit opening 34 of the exit tubing 16, such as within the second conduit 26. An inflatable second bladder 36 is accessible through the second port 32. When inflated, the second bladder 36 closes off the housing 22 from the outside environment.
Pressure waves are introduced between the exit opening 34 of the exit tubing 16 and the housing 22. The pressure waves are generated from a gas line 38 introduced through the second port 32 after inflating the second bladder 36. The gas line 38 connects to a remote pressure wave generator 86, such as pulses of compressed gas from a tank or air compressor. A controller can control the amount, frequency and pressure of the gas pulsed into the filter apparatus 10. For the pressure wave, the gas should be at a high pressure, for example, about 20 psi to about 150 psi.
Alternatively, additional heat can be added to the housing 22 from a heat source through the first port 28 or second port 32 (not shown). A heat gun, water heater element, or propane flame can add heat through the first port 28 or second port 32. The additional heat augments the heat generated by the running engine.
Alternatively, pressure waves can be introduced by pressure wave generator 40 located between the housing 22 and the exit opening 34 of the exit tubing 16. As shown in
The vessel 42 can be located within the second conduit 26 after first disconnecting the exit tubing 16. Alternatively, the vessel 42 can be inserted into the second conduit 26 from the exit tubing 16 or used in the exit tubing 16. The vessel 42 is surrounded by a safety device 46, such as a cage, screen or a shield. The vessel 42 should be made from a stiff polymer having a known bursting pressure, such as polyethylene.
A pressure wave is generated by pressurizing the vessel 42 with the gas until the vessel 42 fails and bursts. The pressure wave generated should be about 100 psi to about 300 psi. The safety device 46 should contain any vessel debris. The gas source should be a high pressure air source, such as compressed air, an air compressor or compressed nitrogen. Preferably, the first bladder 30 is inflated within the first conduit 24 to protect the catalytic device 18 from any pressure waves.
The controller 64 can include electronic controls for manual inputs or can be programmed for automatic control. The controller 64 can be in communication with pressure sensors located in the fuel line 56, the gas line 58 and the exit tubing 16 or second conduit 26.
The fuel can be any fuel that ignites such as propane or other aerosols and can be pressurized. The gas is an oxygen source, is preferably compressed and can be air.
A cycle of pressure wave generation starts after the bladder 54 shown in
The controller 64 can control the cycle by controlling the delivery of gas, fuel and ignition. After oxygen reaches a level between the bladder 54 and the housing 22, the controller 64 can stop the flow of gas. The controller 64 can next start the fuel flow and ignite the igniter 66. The controller 64 can switch on the ash collecting apparatus 84 for removing the ash particles after igniting the fuel. Once the pressure drops in the chamber 68 after the explosion, the controller 64 can restart the cycle.
The ports 28, 32 are normally plugged during normal operating conditions. When the diesel particulate filter needs cleaning, the plugs are removed from the ports to allow cleaning and inflation of the bladders.
The diesel particulate filter 20 and its housing 22 can also be removed from the vehicle and cleaned using the pressure waves. As shown in
The method of the invention has a number of advantages. By leaving the diesel particulate filter attached to the chassis, the filter handling requirement for this method is reduced and thus has a lower risk of damage to the filter. Yet if desired, the filter can be removed from the vehicle and cleaned using the method of the invention.
The method is economical. The equipment used to clean the diesel particulate filter is readily available in a service shop.
While the invention is shown in only one of its forms, it is not thus limited but is susceptible to various changes and modifications without departing from the spirit and scope of the invention.
