Patent Application
20050056008
1. Field of the Invention
The present invention relates to a particulate removing apparatus and more particularly to the particulate removing apparatus which is preferable to be adapted to collect particulates contained in exhaust gas from an internal combustion engine such as an diesel engine or a like used for a diesel engine vehicle, an electric generator, an agricultural implement, or like by using a heater and a filter and to burn and remove the collected particulates and to the diesel engine vehicle equipped with the particulate removing apparatus.
The present application claims two priorities of Japanese Patent Application No. 2003-359980 filed on Sep. 10, 2003, and No. 2003-424409 filed on Dec. 22, 2003, which are hereby incorporated by reference.
2. Description of the Related Art
In emission regulations on exhaust gas from vehicles, attention has been directed conventionally to nitrogen oxide (NOx) or a like which mainly contains nitrogen dioxide being considered as a carcinogen. Exhaust gas from a diesel engine vehicle contains a large amount of carbon particulates (so-called black smoke). The carbon particulates, after having been puffed out through an exhaust gas path in the air, remain suspended in the air for a long time and, in the end, settle, in a form of soot or a like, onto a floor surface, road surface, clothes, or a like. In recent years, reports have been successively made that, since carbon making up such the carbon particulates easily adsorbs substances, various chemical substances such as carcinogenesis related substances are adsorbed by the carbon particulates flying in the air and humans inhales the carbon particulates which enter the human body, thus causing cancers or respiratory diseases.
In such a circumstance, particulate materials (PM) exhausted from a diesel engine vehicle, in addition to NOx, present a significant problem in emission regulations. To try to solve this problem, a black smoke removing apparatus is disclosed in, for example, Japanese Model Utility Application Nos. Sho 61-55114 and Sho 61-84851 in which, as an apparatus to protect environmental air from diesel black smoke pollution, a black smoke removing filter made up of a metal fiber, a honeycomb-shaped element or a like is attached to an exhaust gas path of a vehicle-mounted diesel engine. However, such the black smoke removing filter as disclosed above has a shortcoming that its long time use causes clogging of a mesh of the filter due to collected black smoke, which causes a loss of pressure. As a means for solving the problem of clogging of a mesh caused by black smoke, a diesel particulate removing apparatus is disclosed in, for example, Japanese Patent Application Laid-open Nos. Hei 2-173310, Hei 6-212954 and Hei 8-193509 in which a filtering function is regenerated by burning collected diesel particulates. The apparatus of this type is made up of a cylindrical container having an entrance and an exit of exhaust gas, a heater mounted on a side of the entrance of the cylindrical container, a porous foam filter arranged so as to be adjacent to a rear portion of the heater, and a catalyst supporting filter arranged so as to be adjacent to a rear portion of the porous foam filter.
The particulate removing apparatus having such the configurations as above is so configured that exhaust gas introduced from the entrance comes into contact with the heater made of ceramic or metal and already heated, causing ignition and burning of the particulates and the burnt particulates are then collected by the porous foam filter and by the catalyst supporting filter. At this time point, the heat generated by the heater and given off by the exhaust gas is transmitted to the porous foam filter and lets unburned particulates collected by the porous foam filter be ignited and burnt. In the catalyst supporting filter mounted on a lower stream side, since an amount of the heat transmitted from the heater and exhaust gas becomes small, though its temperature becomes low, burning of collected particulates is facilitated by the catalyst supported by the catalyst supporting filter and, therefore, ignition does not occur and most of collected particulates are burnt and removed at a comparatively low temperature, which, as a result, regenerates functions of the clogged filter.
However, such the conventional particulate removing apparatus has a problem. That is, the configuration in which functions of the filter are to be generated by the heater embedded in the apparatus is idealistic, however, it is complex, expensive, and inferior in durability.
On the other hand, even in a filter in which no clogging of a mesh has occurred, if a large amount of exhaust gas containing large amounts of oxygen, together with black smoke, flows rapidly into a diesel particulate removing apparatus, a phenomenon in which unburned particulates burns in an explosive manner, that is, a phenomenon called “oxygen flash” occurs in the diesel particulate removing apparatus which arouses a fear of a damage of the filter or a like. For example, in a long descent or a like, if a driver presses down on an accelerator after having used an exhaust brake adapted to brake a diesel engine by stopping the exhaust, exhaust gas containing oxygen at a high concentration (for example, being four times higher than usual), together with diesel particulates, flows rapidly into the diesel particulate removing apparatus which causes the diesel particulates to burn in an explosive manner and the temperature generated by the burning reaches up to about 1500° C., thus arousing a fear of melting of, for example, a metal filter.
In view of the above, it is an object of the present invention to provide a particulate removing apparatus being capable of regenerating, with ease and at a low cost, a function of a filter in which advanced clogging of its mesh has occurred and a diesel engine vehicle equipped with the diesel particulate removing apparatus. It is another object of the present invention to provide a particulate removing apparatus which is capable of preventing explosive burning of particulates in a gas caused for some reason and of preventing, even if the explosive burning occurs, burning of the diesel particulate removing apparatus itself and a diesel engine vehicle equipped with the diesel particulate removing apparatus.
According to a first aspect of the present invention, there is provided a diesel particulate removing apparatus including:
In the foregoing, a preferable mode is one wherein a safety valve is mounted in the inner cylinder, which is used to let the diesel exhaust gas flow into the emergency bypass flow-path when pressure in the inner cylinder increases rapidly.
Also, a preferable mode is one wherein apertures with lids to attach and detach the two or more filters are mounted on side surfaces of the outer cylinder.
According to a second aspect of the present invention, there is provided a diesel particulate removing apparatus including:
In the foregoing, a preferable mode is one wherein gaskets are inserted between the two or more filters, between one of the two or more filters placed on a most upstream side and the flow-in cylinder, and between one of the two or more filters placed on a most downstream side and the flow-out cylinder, which make up the inner cylinder of a sealed structure.
Also, a preferable mode is one wherein a joint cylinder with the gaskets to connect the two or more filters each other is mounted in the inner cylinder.
Also, a preferable mode is one wherein aperture portions with lids to attach and detach each of the two or more filters are formed on a side surface of the outer cylinder.
Also, a preferable mode is one wherein, to mount the inner cylinder, lid portions of the apertures for attaching and detaching are opened and then each of the filters is inserted from each of the apertures for attaching and detaching and, to disassemble the inner cylinder, an attaching and detaching unit to take out each of the two or more filters from each of the apertures for attaching and detaching is used.
Also, a preferable mode is one wherein the attaching and detaching unit has a single long bolt or two or more long bolts.
Also, a preferable mode is one wherein the attaching and detaching unit has a single long bolt or two or more long bolts and a single double-nut or two or more double-nuts.
Also, a preferable mode is one wherein a flat spring member to fix the outer cylinder and inner cylinder and to absorb thermal expansion is mounted in a clearance in an axial direction between the inner cylinder on a side of flow-out or on a side of flow-in of exhaust gas and the outer cylinder.
Also, a preferable mode is one wherein the long bolt for the attaching and detaching unit is inserted into an end portion on a side of flow-in or on a side of flow-out of exhaust gas in the outer cylinder and the flat spring member to absorb thermal expansion is mounted in a clearance in an axial direction between the inner cylinder on the side of flow-out or on the side of the flow-in of exhaust gas and the outer cylinder wherein, when the long bolt is fastened, the flat spring member is deformed by pressure which causes the inner cylinder to be fixed to the outer cylinder.
Also, a preferable mode is one wherein the flat spring member includes a disc spring in a central portion of which an aperture to let the flow-in cylinder or flow-out cylinder be inserted is formed.
Also, a preferable mode is one wherein a clearance between the inner cylinder and the outer cylinder functions as an emergency bypass flow-path of the diesel exhaust gas when pressure in the inner cylinder increases rapidly.
Also, a preferable mode is one wherein a safety valve is mounted in the inner cylinder, which is used to let the diesel exhaust gas be flown into the emergency bypass flow-path when pressure in the inner cylinder increases rapidly.
Furthermore, a preferable mode is one wherein a clogging alerting sensor to alert an operator to clogging in a mesh of each of the two or more filters.
According to a third aspect of the present invention, there is provided a diesel engine vehicle being equipped with the diesel particulate removing apparatus described above.
With the above configuration, a function of a filter in which advanced clogging of its mesh has occurred can be regenerated with ease and at a low cost. Also, explosive burning of diesel particulates caused for some reason can be prevented and even if the explosive burning occurs, burning of the diesel particulate removing apparatus itself can be prevented
The above and other objects, advantages, and features of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which:
Best modes of carrying out the present invention will be described in further detail using various embodiments with reference to the accompanying drawings. An aim of regenerating, at ease and at a low cost, a function of a filter in which advanced clogging of its mesh has occurred is achieved by constructing an outer cylinder and an inner cylinder made up of filters or a like so that the outer and inner cylinders are of a dual-cylinder structure and by forming lid-mounted aperture portions used to attach and detach the filters serving as components of the inner cylinder in the above outer cylinder. Unburned particulates remaining in the filter detached from the outer cylinder are burnt in a regeneration furnace and the function of the filter can be regenerated.
Inner configurations of the diesel particulate removing apparatus of the embodiment are described by referring to
Furthermore a disc spring 20 and a by-pass valve (safety valve) 15 are attached to the front lid portion 8B including the flow-in cylinder 6 as will be described later.
As shown in
To the rear lid portion 4C is attached the attaching and detaching means 12 to be used freely to attach and detach the inner cylinder 8 and the outer cylinder 4 that houses the inner cylinder 8. As shown in
As shown in
The diesel particulate removing apparatus of the embodiment is so configured that, while a diesel engine is driven, at time of a rapid increase in pressure of the exhaust gas 3 in the inner cylinder 8 caused for some reason, a cross-zonal clearance between an external surrounding surface of the inner cylinder 8 and an internal surrounding surface of the outer cylinder 4 serves as an emergency bypass flow-path K which prevents explosive burning such as oxygen flash or a like (see
In the by-pass valve 15, on a stead basis, a valve bar (not shown) blocks the by-pass valve 15 with a spring force of a compressed coil spring (not shown), otherwise, on a time of emergency, when the exhaust pressure in the inner-cylinder 8 exceeds a specified value the valve bar is backed away and the by-pass valve 15 is opened. As the result through the by-pass valve 15 the exhaust gas in the inner-cylinder 8 is flown into the cross-zonal clearance between the external surrounding surface of the inner cylinder 8 and the internal surrounding surface of the outer cylinder 4 (the emergency bypass flow-path K) and the exhaust gas in the inner-cylinder 8 is exhausted outside of the inner-cylinder 8.
Moreover, in the rear lid portion 4C in the outer cylinder 4 is formed, in addition to a bolt inserting hole, an emergency exhaust exit that serves as an exit for the exhaust gas 3 flown through the emergency bypass flow-path K.
Also, for safety, pressure sensors (clogging alerting sensor) 16 to alert operators to clogging of a mesh of the filter units 5 are attached to a side of an upstream of the exhaust gas 3 and to a side of a downstream of the exhaust gas 3. Moreover, a temperature sensor T is mounted in a central portion of the apparatus. On the side of the upstream of the exhaust gas 3 in the front filter unit 5 is mounted a collision plate 17 adapted to reduce a speed of flow of the diesel exhaust gas 3 flowing out of the flow-in cylinder 6 at a high speed and to disperse the exhaust gas 3 uniformly within the filter unit 5.
Next, a filter portion 5B being a core portion of the filter unit 5 is described by referring to FIGS. 8 to 10. As shown in
Next, operations of the diesel particulate removing apparatus of the embodiment are explained.
Mounting of Filter Units 5
To attach the filter units 5 to the outer cylinder 4, in other words, to insert the inner cylinder 8 into the outer cylinder 4 for assembly, in a state in which the front lid portion 8B (flow-in cylinder 6) and the rear lid portion 8C (flow-out cylinder 7) are mounted in advance in the outer cylinder 4, side lids 10 of the aperture portions 11 for attaching and detaching are opened first and each of the filter units 5, joint cylinder 9 with a gasket, gaskets of another kind (not shown) are inserted from the aperture portions 11 for attaching and detaching. Next, a long bolt 13A serving as an attaching and detaching means 12 is inserted into a bolt inserting hole formed in the rear lid portion 4C of the outer cylinder 4 and, by using a tool, a nut (double nut) 13B is screwed in to press a disc spring 14 into a clearance in an axial direction between the inner cylinder 8 and outer cylinder 4 on a flow-in side (see
Operations of Black Smoke Particulate Removing Apparatus
The black smoke particulate removing apparatus having the configurations as above is used in a diesel engine vehicle, that is, it is embedded into an exhaust gas path of a diesel engine for use. In the black smoke particulate removing apparatus, while a diesel engine is being operated, as shown in
Taking-Out of Filter Units 5 and Regeneration of Functions of Filter Units 5
When clogging of the mesh occurs the filter unit 5 (metal filter 19), the pressure sensors 16 (clogging alerting sensor) alerts an operator to the clogging of the mesh of the filter units 5. After that, the operator disassembles the inner cylinder 8 and takes out the mesh-clogged filter units 5. To take out the mesh-clogged filter units 5, the side lids 10 of the aperture portions 11 for attaching and detaching are opened and, using a tool, a long bolt 13A serving as an attaching and detaching means 12 mounted on the rear lid 4C in the outer cylinder 4 is loosened. Then, the disc spring 14 is released from pressure which causes each components of the inner cylinder 8 (each of filter units 5, joint cylinder 9 with the gasket, front lid portion 8B on the side of the flow-in cylinder 6, and rear lid portion 8C on the side of the flow-out cylinder 7 (see
Re-Mounting of Filter Units 5
To re-mount the filter units 5 in the outer cylinder 4, the side lids 10 of the aperture portions 11 for attaching and detaching are again opened and each of the filter units 5 is inserted from the aperture portions 11. Next, the long bolt 13A serving as the attaching and detaching means 12 is inserted into the bolt inserting hole of the rear lid 4C in the outer cylinder 4 and then the nut (double nut) 13B is screwed in to press the inserted disc spring 14 into the clearance in an axial direction between the inner cylinder 8 and outer cylinder 4 on the side of the flow-in of the exhaust gas 3 (see
Operations of Safety Device
While the diesel engine is being operated, if pressure of the exhaust gas 3 in the inner cylinder 8 increases rapidly for some reason, the bypass valve (safety valve) 15 opens. As a result, the high-pressure exhaust gas 3 is exhausted through the opened bypass valve (safety valve) and then through the emergency bypass flow-path K between the external surrounding surface of the inner cylinder 8 and the inner surrounding surface of the outer cylinder 4 from an emergency exhaust hole formed in the rear lid portion 4C in the outer cylinder 4 (see
It is apparent that the present invention is not limited to the above embodiments but may be changed and modified without departing from the scope and spirit of the invention. For example, in the above embodiment, the attaching and detaching means 12 to connect the inner cylinder 8 and outer cylinder 4 so as to be freely attached or detached is mounted on a flow-out side of the exhaust gas 3. However, the attaching and detaching means 12 may be mounted on the flow-in side of the exhaust gas 3. The attaching and detaching means is not limited to the long bolts 13A, 13A, . . . and the nuts (double nuts) 13B, 13B, . . . . Moreover, in the above embodiment, a flat spring member (disc spring 14) is mounted in a clearance in an axial direction between the front lid section 8B in the inner cylinder 8 and the front lid portion 4B in the outer cylinder 4. However, the flat spring member may be mounted between the rear lid portion 8C in the inner cylinder 8 and the rear lid portion 4C in the outer cylinder 4. The flat spring member is not limited to a disc spring.
Moreover, the particulate removing apparatus of the present invention can be applied not only to a diesel engine vehicle but also to all internal combustion engines, for example any internal combustion engine used for an emergency generator, a personal generator, an agricultural implement, and a like. Furthermore, the particulate removing apparatus of the present invention is not limited to be attached to an exhaust gas path of a diesel exhaust gas and it is valuable to be attached to a flow path of different kinds of gases.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2003-359980 | Sep 2003 | JP | national |
| 2003-424409 | Dec 2003 | JP | national |
