Patent Publication Number: US-2003223922-A1

Title: Structure and method for improving metal honeycomb core body of catalyst converters

Description:
FIELD OF THE INVENTION  
       [0001] The present invention is related to metal honeycomb core body of catalyst converters, more particularly, related to improving the center portion of honeycomb core body of catalyst converters with an easier fabricating method.  
       BACKGROUND OF THE INVENTION  
       [0002] In general, catalyst converters are adapted to use under high temperature environment by a heat-resistant honeycomb structure for purifying exhausting toxic gas. An elongate matrix having a flat sheet and a corrugated sheet are superimposed and rolled up for forming the aforementioned heat-resistant honeycomb structure.  
       [0003] Please referring to FIG. 1A˜ 1 D, the prior art of catalyst converters for purifying the exhausting gas from an engine (such as the general gas engine), which are formed by an elongate matrix  1  having a flat sheet  12  and a corrugated sheet  11 , wherein said elongate matrix  1  is applied with soldering material thereon. A predetermined line A-A is set at the adjacence of said flat sheet  12  and said corrugated sheet  11  for being superimposed and rolled up to form a honeycomb structure  10 . Then, inserting said honeycomb structure  10  into a hollow cylindrical shell  3  to form a catalyst converter (as shown in the FIG. 1D) by heating process, wherein said hollow cylindrical shell  3  is applied with soldering material on the inner wall thereof for fixing said honeycomb structure  10  into said hollow cylindrical shell  3  after heating process. Said honeycomb structure  10  further comprises a plurality of channel  100  for the exhausting gas flowing through. The surface of the honeycomb structure  10  is covered with catalyst, such as the noble metal catalyst: platinum Pt, palladium Pd, and rhodium Rh, to change the noxious emissions, such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOX), into non-toxic gas, such as carbon dioxide (CO 2 ), water (H 2 O), and nitrogen (N 2 ) by the catalytic action for purifying the exhausting toxic gas from an engine. In addition, the catalytic action is an exothermic reaction, so the higher performance of the catalyst converter reacts, the higher thermal will be generated. However, when gas flows through the honeycomb structure  10 , the speed of the gas flowing through the center of the honeycomb structure  10  is the fastest, by contrast, the farther the gas flows through away from the center of the honeycomb structure  10 , the lower the speed of gas flows through therein. Thus, according to the fastest speed of the gas flowing through the center portion, it generates the highest temperature therein, and the temperature in the center portion of the honeycomb structure  10  is the highest. When the gas engine is under high-loaded or unfired status, the incompletely reacted gas flows through the honeycomb structure  10  causes temperature increasing dramatically in its center portion, even over 1,200° C., and furthermore, causes the center portion of the honeycomb structure melted and destroys the whole catalyst converter. In the U.S. Pat. No. 5,302,355, Exhaust Purifying Device and Method of Producing the same, which discloses an exhaust purifying device for an internal combustion engine. Its honeycomb core is constituted by a single webbing that is implemented as foil of stainless steel. The webbing is made up of a flat portion and a corrugated portion adjoining each other in the longitudinal direction of the webbing. The flat portion is held by a core metal forming part of a jig at a particular position that is a predetermined distance remote from a position where the corrugated portion begins. The core metal is rotated about its own axis in such a direction that the flat portion underlies the corrugated portion and forms a small hole therein. However, the diameter of that small hole is usually smaller than 10 mm, therefore, the center portion of the core metal is easy to be melted.  
       [0004] In order to solve the problem of center portion of the honeycomb structure melted by high thermal exothermic reaction, it is important to provide a structure and a method for improving metal honeycomb core body of catalyst converters. Therefore, the present invention is provided to reduce the high temperature in the center of the metal honeycomb core body of catalyst converters, and further to avoid the structure to be destroyed by high thermal reaction. In addition, another object of the present invention is to reduce consumption of an engine horsepower by decreasing the back pressure caused by the exhausted gas resistance.  
       SUMMARY  
       [0005] The present invention provides a structure and a method for improving metal honeycomb core body of catalyst converters, which is composed of an elongate matrix having a flat sheet and a corrugated sheet. Said flat sheet and said corrugated sheet are superimposed and rolled up to form a central heat-resistant structure and a honeycomb structure for improving metal honeycomb core body of catalyst converters; wherein said central heat-resistant structure having a specific diameter substantially larger than 10 mm for forming at least a diffusion channel to increase the exhausting gas flowing through and decrease the temperature therein; and said honeycomb structure surrounding said central heat-resistant structure for catalytic reaction. Due to the catalytic reaction area of said diffusion channel is very small, it reduces the efficiency of reaction in the center portion of the metal honeycomb core body of catalyst converter, and it further reduces temperature increasing by its exothermic reaction. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0006] The present invention will be better understood from the following detailed description of preferred embodiments of the invention, taken in conjunction with the accompanying drawings, in which  
     [0007]FIG. 1A is a perspective view of a single matrix of a traditional honeycomb core;  
     [0008]FIG. 1B is a side elevation of FIG. 1A;  
     [0009]FIG. 1C is a section showing the traditional honeycomb core formed by the procedure of FIG. 1B;  
     [0010]FIG. 1D is an exploded perspective view of a traditional catalyst converter;  
     [0011]FIG. 2 is a side elevation of a single matrix for constituting a honeycomb core embodying the present invention;  
     [0012]FIG. 3A is an exploded perspective view of a catalyst converter;  
     [0013]FIG. 3B is an exploded perspective view of a central heat-resistant structure of the honeycomb core in accordance with the present invention; and  
     [0014]FIG. 4 is an exploded perspective view of a catalyst converter embodying the present invention formed by the procedure of FIG. 3A.  
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0015] The following descriptions of the preferred embodiments are provided to understand the features of the present invention.  
     [0016] The present invention provides a structure for improving metal honeycomb core body of catalyst converters, please referring to the FIG. 2, which is composed of an elongate matrix  2  having a flat sheet  22  and a corrugated sheet  21 , in a preferred embodiment, said matrix  2  is applied with soldering material. After setting a predetermined line B-B, the flat sheet  22  and corrugated sheet  21  are superimposed and rolled up from the line B-B. In the preferred embodiment, said elongate matrix  2  is composed of a alloy foil having soldering material applied thereon; wherein said alloy foil is selected from the group consisting of iron, chromium, and aluminum. Furthermore, the predetermined line B-B is located on said flat sheet  22  and remote from the adjacence of said flat sheet  22  and said corrugated sheet  21  (as the A-A line, shown in FIG. 1A), which demonstrates a specific distance S between the adjacency and line B-B. Next, referring to the FIG. 3A, after superimposing and rolling up said flat sheet  22  and said corrugated sheet  21 , a central heat-resistant structure  30  and a honeycomb structure  20  are formed through appropriate heating process; wherein the honeycomb structure  20  is located around the central heat-resistant structure  30 . A hollow cylindrical shell  4  is provided for inserting the honeycomb structure  20  and the central heat-resistant structure  30  into therein, in the preferred embodiment, said hollow cylindrical shell  4  is composed of heat-resistant stainless steel and applied with soldering material on its inner wall for fixing the honeycomb structure  20  and the central heat-resistant structure  30  after the heating process, as shown in the FIG. 4, which is employed for purifying the exhausting gas, for example for the catalyst converter of a gas engine. Particularly, the distance S is based on the specific diameter D of said central heat-resistant structure  30 , and moreover, said diameter D is much longer than the height h (between the peaks of p and v), as shown in the FIG. 2. In the preferred embodiment, said diameter D is substantially larger than 10 mm for forming said diffusion channel  300  to increase the exhausting gas flowing through and decrease the temperature therein.  
     [0017] Please referring to the FIG. 3B, due to the diameter D of the central heat-resistant structure  30  is substantially larger than 10 mm, the diffusion channel  300  has a greater diffusion space for decreasing the back pressure caused by the exhausting gas resistance; and furthermore, due to the area of catalytic action is comparatively small, the thermal increased by the exothermic catalytic reactions is decreasing, and it may avoid the structure of the central portion to be melted and destroyed. Therefore, the consumption of horsepower of the engine (such as the gas engine) may be reduced. The central heat-resistant structure  30  further comprises a supporting portion  31  for supporting said honeycomb structure  20 , and furthermore, for avoiding its structure deformed.  
     [0018] The present invention provides a method for improving metal honeycomb core body of catalyst converters, referring to the FIG. 2˜FIG. 4, first, providing an elongate matrix  2 , wherein said elongate matrix  2  having a flat sheet  22  and a corrugated sheet  21 , and furthermore, a predetermined line B-B being set on said flat sheet  22 . In the preferred embodiment, said elongate matrix  2  is composed of a alloy foil having soldering material applied thereon and selected from the group consisting of iron, chromium, and aluminum. And second, superimposing and rolling up said flat sheet  22  and said corrugated sheet  21  from said determined line B-B. Then, it forms a central heat-resistant structure  30  and a honeycomb structure  20  after heating process, wherein said central heat-resistant structure  30  has a specific diameter D larger than 10 mm, and said honeycomb structure  20  is surrounding said central heat-resistant structure  30 . Next, inserting said central heat-resistant structure  30  and said honeycomb structure  20  into a hollow cylindrical shell  4 , in the preferred embodiment, said hollow cylindrical shell  4  is composed of stainless steel and applied with soldering material on its inner wall. Said central heat-resistant structure  30  and said honeycomb structure  20  will be fixing into said hollow cylindrical shell  4  by vacuum soldering process, as shown in FIG. 4 for the exploded perspective view. A diffusion channel is formed for increasing the exhausting gas flowing through and decreasing the temperature of said metal honeycomb core body of catalyst converters. Furthermore, the predetermined line B-B is located on said flat sheet  22  and remote from the adjacence of said flat sheet  22  and said corrugated sheet  21  (as the A-A line, shown in FIG. 1A), which demonstrates a specific distance S between the adjacency and line B-B. Particularly, the distance S is based on the specific diameter D of said central heat-resistant structure  30 , and moreover, said diameter D is much longer than the height h (between the peaks of p and v), as shown in the FIG. 2. In the preferred embodiment, said diameter D is substantially larger than 10 mm for forming said diffusion channel  300  to increase the exhausting gas flowing through and decrease the temperature therein. Due to the diameter D of the central heat-resistant structure  30  is substantially larger than 10 mm, referring to the FIG. 3B, the diffusion channel  300  has a greater diffusion space for decreasing the back pressure caused by the exhausting gas resistance; and furthermore, due to the area of catalytic action is comparatively small, the thermal increased by the exothermic catalytic reactions is decreasing, and it may avoid the structure of the central portion to be melted and destroyed. Therefore, the consumption of horsepower of the engine (such as the gas engine) may be reduced. The central heat-resistant structure  30  further comprises a supporting portion  31  for supporting said honeycomb structure  20 , and furthermore, for avoiding its structure deformed.  
     [0019] The present invention may be embodied in other specific forms without departing from the spirit of the essential attributes thereof; therefore, the illustrated embodiment should be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.  
     [0020] In summation of the foregoing section, the improved structure for improving metal honeycomb core body of catalyst converters of the invention herein is an invention of reasonable perfection that not only possesses outstanding practicality, but has an unprecedented structural spatial design that is original and innovative and, furthermore, adapting a diffusion channel have a larger space for exhausting gas flowing through and a greater rate of decreasing horsepower of the engine that is manifestly capable of increased catalyst converters performance, is a solution to the height characteristics of inventions based on the conventional technology and, furthermore, is progressive and not a conception based merely on familiarity of utilization; therefore, the invention herein fully complies will all new patent application requirements and is hereby submitted to the patent bureau for review and the granting of the commensurate patent rights.