DRIP-IRRIGATION CATALYTIC REDUCTION EXHAUST PIPE

Abstract

A drip-irrigation catalytic reduction exhaust pipe includes an exhaust pipe having a pipe wall in which a plurality of first apertures is formed and a plurality of direct-through ceramic filters arranged in the exhaust pipe in an axial direction from an exhaust gas inlet opening toward the exhaust gas outlet opening, or alternatively, a wall-flow filter being arranged at a location that is closest to the exhaust gas outlet opening. A flow guide tube is arranged outside the exhaust pipe and is connected to a container and includes a plurality of second apertures. The second apertures respectively correspond to the first apertures. An electromagnetic valve controls passage of urea liquid contained in the container through the second apertures and the first apertures to drip into the exhaust pipe and absorbed by a ceramic fiber material for penetration into pores of the direct-through ceramic filters and the wall-flow filter.

Claims

1. A drip-irrigation catalytic reduction exhaust pipe, comprising: an exhaust pipe, which comprises an exhaust gas inlet opening and an exhaust gas outlet opening respectively formed in two axial ends and in communication with each other, the exhaust pipe having a pipe wall in which a plurality of first apertures is formed; a plurality of direct-through ceramic filters, which has an outer circumference surrounded by a ceramic fiber material and is arranged in the exhaust pipe in such a way of being lined up, in an axial direction of the exhaust pipe, from the exhaust gas inlet opening towards the exhaust gas outlet opening; a wall-flow filter, which is arranged in the exhaust pipe at a location that is closest to the exhaust gas outlet opening; and a flow guide tube, which comprises a plurality of second apertures, the flow guide tube being arranged outside the pipe wall of the exhaust pipe such that the second apertures respectively correspond to the first apertures, the flow guide tube being connected to a container that receives and holds therein urea liquid, the flow guide tube being provided, at a location thereof, with an electromagnetic valve, which controls passages of the urea liquid of the container through the second apertures and the first apertures to be absorbed by the ceramic fiber material and subsequently penetrating into pores of the direct-through ceramic filters and the wall-flow filter.

2. The drip-irrigation catalytic reduction exhaust pipe according to claim 1, wherein the wall-flow filter is alternatively replaced by a direct-through ceramic filters.

3. The drip-irrigation catalytic reduction exhaust pipe according to claim 1, wherein the direct-through ceramic filters and the wall-flow filter are arranged to separate from each other in the exhaust pipe.

4. The drip-irrigation catalytic reduction exhaust pipe according to claim 2, wherein the direct-through ceramic filters are arranged to separate from each other in the exhaust pipe.

5. The drip-irrigation catalytic reduction exhaust pipe according to claim 1, wherein the electromagnetic valve is electrically connected to an electrical power supply of an automobile such that when the electrical power supply of the automobile is activated, the electromagnetic valve is activated simultaneously and when the electrical power supply of the automobile is shut down, the electromagnetic valve is closed simultaneously.

6. The drip-irrigation catalytic reduction exhaust pipe according to claim 2, wherein the electromagnetic valve is electrically connected to an electrical power supply of an automobile such that when the electrical power supply of the automobile is activated, the electromagnetic valve is activated simultaneously and when the electrical power supply of the automobile is shut down, the electromagnetic valve is closed simultaneously.

7. The drip-irrigation catalytic reduction exhaust pipe according to claim 1, wherein the first apertures are arranged along a straight line in the axial direction of the exhaust pipe and the second apertures are arranged along a straight line in an axial direction of the flow guide tube.

8. The drip-irrigation catalytic reduction exhaust pipe according to claim 2, wherein the first apertures are arranged along a straight line in the axial direction of the exhaust pipe and the second apertures are arranged along a straight line in an axial direction of the flow guide tube.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 is a plan view, in a sectioned form, showing a first embodiment of the present invention.

[0016] FIG. 2 is a perspective view showing the first embodiment of the present invention.

[0017] FIG. 3 is a plan view, in a sectioned form, showing a second embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The following descriptions are exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.

Embodiment 1

[0019] As shown in FIGS. 1 and 2, the present invention provides a drip-irrigation catalytic reduction exhaust pipe, which, as a first embodiment, comprises an exhaust pipe 1. The exhaust pipe 1 comprises an exhaust gas inlet opening 11 and an exhaust gas outlet opening 12 respectively formed in two axial ends of the pipe and in communication with each other. The exhaust pipe 1 comprises a circumferential pipe wall in which a plurality of first apertures 10 is formed and extends through the pipe wall. The first apertures 10 are arranged along a straight line in the axial direction of the exhaust pipe 1. The exhaust pipe 1 comprises a plurality of direct-through ceramic filters 2 and a wall-flow filter 3 arranged therein; and, preferably, the direct-through ceramic filters 2 and the wall-flow filter 3 are arranged to be spaced from each other in the exhaust pipe 1. Each of the direct-through ceramic filters 2 and the wall-flow filter 3 has an outer circumference that is surrounded by a liquid-absorbent ceramic fiber material 2A. The direct-through ceramic filters 2 are arranged in the exhaust pipe 1 in such a way of being lined up, in the axial direction of the exhaust pipe 1, from the exhaust gas inlet opening 11 towards the exhaust gas outlet opening 12, while the wall-flow filter 3 is arranged at a location that is closest to the exhaust gas outlet opening 12.

[0020] A flow guide tube 4 is arranged outside and along the pipe wall of the exhaust pipe 1. The flow guide tube 4 has a tubular wall in which a plurality of second apertures 41 is formed such that the second apertures 41 are arranged along a straight line in an axial direction of the flow guide tube 4. The flow guide tube 4 is arranged outside the pipe wall of the exhaust pipe 1 in such a way that the second apertures 41 are respectively in alignment with the first apertures 10 for communication with each other. Preferably, the flow guide tube 4 is mounted, by means of welding, to the outer circumference of the pipe wall of the exhaust pipe 1 and peripheries of the first apertures 10 and the second apertures 41 are properly sealed. The flow guide tube 4 is connected to a container 5 that receives and holds therein urea liquid n the container 5. The container 5 is provided, in a top thereof, with a filling opening 51 for filling and replenishment of urea liquid. The flow guide tube 4 is provided, at a suitable location thereon, with an electromagnetic valve 6 for controlling passage of the urea liquid. In the embodiment of the present invention, the electromagnetic valve 6 is electrically connected to an electrical power supply of an automobile such that when the electrical power supply of the automobile is activated, the electromagnetic valve 6 is activated simultaneously; and when the electrical power supply of the automobile is shut down, the electromagnetic valve 6 is closed simultaneously.

[0021] The direct-through ceramic filter makes use of porosity of Cordierite ceramics to capture particulate contaminants emitting from a diesel engine and each passageway of the filter has an end that is open and an opposite end that is closed such that exhaust gas is forced to pass through a porous ceramic wall. Soot particulates generally have particle sizes that are greater than the pores of the ceramic wall and would be caught and collected in the passageway. When the filter reaches an extreme of loading, the soot may be burnt off (oxidization) to resume the function of the core. This process of oxidizing the soot is referred to as “regeneration”. In order to reduce back pressure for not affecting the power of the engine, it is commonly recommended to use a ceramic filter having a capacity that is at least twice of engine displacement as a general reference.

[0022] The wall-flow filter comprises a metallic particulate trap coated with diesel oxidant catalyst (DOC), and is formed by wrapping multiple shovel-shaped metallic corrugated boards with metal filament screen that is then processed to form a metallic honeycomb filter. Within a proper temperature range, such as 200° C.-450° C., DOC may continuously generate NO.sub.2 that flows into the particulate trap such that NO.sub.2 and carbon particulates deposited on the metallic fibrous board continuously generate oxidization regeneration reaction within the proper temperature range (200° C.-450° C.). This process is referred to as continuous passive regeneration. The particulate trap and DOC work collaboratively to reduce carbon particulates contained in the exhaust gas.

[0023] The operation of the present invention, after being installed in an automobile, is as follows. When the automobile is stared up, the electromagnetic valve 6 is activated simultaneously to introduce a proper amount of urea liquid from the container 5, through the second apertures 41 of the flow guide tube 4 and the first apertures 10 of the exhaust pipe 1, into the ceramic fiber material 2A. The ceramic fiber material 2A, after absorbing the urea liquid, is kept in a wet condition and allows the urea liquid to continuously penetrate into each of the direct-through ceramic filters 2 and the wall-flow filter 3. During the course of movement of exhaust gas of a diesel engine that enters from the exhaust gas inlet opening 11 at one end of the exhaust pipe 1 and leaves from the exhaust gas outlet opening 12 at an opposite end, toxicant gases, such as nitrogen oxide (NOx), when flowing, in sequence, through each of the direct-through ceramic filters 2 and the wall-flow filter 3, will be decomposed and reduced by urea or ammonia into diatomic nitrogen and water so as to reduce pollution to the environment. Embodiment 2

[0024] As shown in FIG. 3, a drip-irrigation catalytic reduction exhaust pipe according to a second embodiment of the present invention comprises a structure that is similar to that of the previous embodiment and a difference resides in that the exhaust pipe 1 comprises only a plurality of direct-through ceramic filters 2 that are axially arranged and no wall-flow filter is included. As such, when an automobile is stared up, the electromagnetic valve 6 is activated simultaneously to introduce a proper amount of urea liquid from the container 5, through the second apertures 41 of the flow guide tube 4 and the first apertures 10 of the exhaust pipe 1, into the ceramic fiber material 2A. The ceramic fiber material 2A, after absorbing the urea liquid, is kept in a wet condition and allows the urea liquid to continuously penetrate into each of the direct-through ceramic filters 2. During the course of movement of exhaust gas of a diesel engine that enters from the exhaust gas inlet opening 11 at one end of the exhaust pipe 1 and leaves from the exhaust gas outlet opening 12 at an opposite end, toxicant gases, such as nitrogen oxide (NOx), when flowing, in sequence, through each of the direct-through ceramic filters 2, will be decomposed and reduced by urea or ammonia into diatomic nitrogen and water so as to reduce pollution to the environment.

[0025] It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.

[0026] While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the claims of the present invention.