Waste gas treatment catalytic material testing device
By designing a catalytic material testing device for exhaust gas treatment, the problem of unknown catalytic material data is solved, and effective testing and data provision of catalytic materials are realized, supporting the improvement of catalytic materials and device design.
Patent Information
- Application Number
- CN202422306999.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-20
- Publication Date
- 2025-08-26
- Estimated Expiration
- 2034-09-20
AI Technical Summary
In the existing RTO waste gas treatment system, the catalytic effect, life and activity data of the catalytic material of the catalytic device are unknown, resulting in the exhaust of flue gas exceeding the standard, and a test device is required to design a test device for data inspection.
A test device for the catalytic material treatment of exhaust gas is designed, including a catalytic chamber, heating mechanism, fan mechanism and testing mechanism, which controls the exhaust gas temperature through heating and tests the effect of the catalytic material, voc maximum concentration treatment capacity and upper and lower limits of catalytic temperature.
Effectively test the catalytic effect, voc maximum concentration processing capacity and catalytic temperature range of the catalytic material, and provide data parameters for the improvement of catalytic material and device design.
Smart Images
Figure CN223272494U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of waste gas treatment, in particular to a waste gas treatment catalytic material testing device. Background Art
[0002] In color coating and laminating production lines and paint bucket cleaning plants, RTO waste gas treatment systems are currently commonly used to incinerate and crack waste gas or unorganized volatile paint. However, due to the treatment efficiency issues of RTO waste gas treatment systems, excessive flue gas is still discharged at the exhaust outlet.
[0003] Existing technology involves connecting a catalytic device in series with the RTO exhaust gas treatment system to treat flue gases exceeding standards. However, users often lack visibility into the effectiveness of the catalytic materials within the device. Therefore, a device is needed to test the catalytic effect, lifespan, and activity of the catalytic materials within the device. This allows for accurate data on the catalytic materials. Furthermore, this device can provide data parameters for new catalytic materials during subsequent development or design, enabling improvements and upgrades. Utility Model Content
[0004] In order to overcome the above technical defects, the purpose of the present invention is to provide an exhaust gas treatment catalytic material testing device for solving the problem of how to test the data parameters of the catalytic material in the background technology.
[0005] In order to achieve the above purpose, the present invention provides the following technical solutions:
[0006] The utility model discloses a test device for exhaust gas treatment catalytic materials, comprising:
[0007] a catalytic compartment having an input end and an output end;
[0008] an exhaust gas inlet pipe, which is connected to the input end of the catalytic chamber and is provided with an exhaust gas inlet port;
[0009] a heating mechanism, which is provided on the exhaust gas inlet pipe and is used to heat the exhaust gas in the exhaust gas inlet pipe;
[0010] an exhaust gas output pipe, which is connected to the output end of the catalytic chamber;
[0011] a fan mechanism, which is provided on the exhaust gas output pipe and is used to generate a wind flow in a direction from the exhaust gas input pipe to the exhaust gas output pipe;
[0012] A testing mechanism is arranged at the exhaust gas output pipe and is used to test the exhaust gas discharged from the exhaust gas output pipe.
[0013] Compared with the prior art, the present application innovatively sets up a test device for exhaust gas treatment catalytic materials, which heats the exhaust gas in the exhaust gas inlet pipe through a heating mechanism, effectively controls the temperature of the exhaust gas, and meets the different temperature requirements of the catalytic material in the catalytic chamber. The testing mechanism tests the exhaust gas discharged from the exhaust gas output pipe, thereby testing the catalytic effect of the catalytic material, the ability to treat the highest concentration of VOC, the upper and lower limits of the catalytic temperature, and the activity of the catalytic material under long-term use.
[0014] In one embodiment, the exhaust gas output pipe is provided with an exhaust gas outlet;
[0015] The testing mechanism includes an anemometer, which is arranged at the exhaust gas outlet.
[0016] In one embodiment, a bypass output branch pipe is provided on the exhaust gas output pipe, and the bypass output branch pipe is arranged close to the exhaust gas outlet;
[0017] The bypass output branch pipe is provided with an exhaust gas total hydrocarbon measuring port and a branch pipe switch valve;
[0018] The testing mechanism includes a smoke detector, which is arranged at the exhaust gas total hydrocarbon measuring port.
[0019] In one embodiment, the exhaust gas treatment catalytic material testing device further includes a bypass pipe and a control valve assembly, wherein the bypass pipe has an air inlet end and an air outlet end, wherein the air inlet end is connected to the exhaust gas input pipe, and the air outlet end is connected to the exhaust gas output pipe;
[0020] Under the selective action of the control valve assembly, the exhaust gas in the exhaust gas inlet pipe flows into the exhaust gas outlet pipe through the bypass pipe, or,
[0021] The exhaust gas in the exhaust gas input pipe flows into the exhaust gas output pipe through the catalytic chamber.
[0022] In one embodiment, the control valve assembly includes a bypass passage control valve and a catalytic passage control valve, the bypass passage control valve is arranged at the intake end, and the catalytic passage control valve is arranged at the input end.
[0023] In one embodiment, the catalytic box includes a box body and a cover body, and the cover body is covered on the box body; a plurality of limiting brackets are provided in the box body, and a catalytic space for placing catalytic materials is formed between the plurality of limiting brackets.
[0024] In one embodiment, the compartment is provided with an input pipe and an output pipe, the input pipe is connected to the input end, and the output pipe is connected to the output end; the input pipe and the output pipe are correspondingly arranged.
[0025] In one embodiment, a pre-catalytic thermocouple and a post-catalytic thermocouple are provided in the catalytic chamber. The pre-catalytic thermocouple is disposed close to the input pipe, and the post-catalytic thermocouple is disposed close to the output pipe.
[0026] In one embodiment, the heating mechanism includes a tubular heater; the exhaust gas inlet is provided with an incoming gas temperature thermocouple.
[0027] In one embodiment, the exhaust gas output pipe includes a serpentine cooling section, and the serpentine cooling section is located between the output end of the catalytic chamber and the fan mechanism. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein:
[0029] Figure 1 A three-dimensional diagram of the exhaust gas treatment catalytic material testing device of the present invention (the catalytic chamber is shown in cross section);
[0030] Figure 2 This is a front view of the exhaust gas treatment catalytic material testing device of the utility model;
[0031] Figure 3 This is a three-dimensional diagram of the catalytic chamber of the exhaust gas treatment catalytic material testing device of the present invention.
[0032] Description of reference numerals:
[0033] 10 catalytic compartment, 101 input end, 1011 catalytic passage control valve, 102 output end, 110 compartment body, 111 limiting bracket, 112 input pipe, 113 output pipe, 120 cover body, 130 thermocouple before catalysis, 140 thermocouple after catalysis, 20 exhaust gas input pipe, 201 exhaust gas inlet, 30 heating mechanism, 310 incoming gas temperature thermocouple, 40 exhaust gas output pipe, 401 exhaust gas outlet, 402 bypass output branch pipe, 403 exhaust gas total hydrocarbon measuring port, 404 branch pipe switching valve, 410 serpentine cooling section, 50 fan mechanism, 61 anemometer, 62 anemometer bracket, 70 bypass pipe, 71 bypass passage control valve, 80 catalytic material. DETAILED DESCRIPTION
[0034] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.
[0035] In order to better illustrate the present invention, the present invention is further described in detail below with reference to the accompanying drawings.
[0036] It should be clear that the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the embodiments of the present application.
[0037] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the embodiments of the present application. The singular forms "a," "the," and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.
[0038] In addition, in this application, unless otherwise specified, "plurality" refers to two or more. "And / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.
[0039] Combine Figures 1 to 3 As shown, the utility model discloses a test device for exhaust gas treatment catalytic material 80, comprising: a catalytic chamber 10, which has an input end 101 and an output end 102; an exhaust gas inlet pipe 20, which is connected to the input end 101 of the catalytic chamber 10, and the exhaust gas inlet pipe 20 is provided with an exhaust gas inlet port 201; a heating mechanism 30, which is arranged on the exhaust gas inlet pipe 20, and is used to heat the exhaust gas in the exhaust gas inlet pipe 20; an exhaust gas output pipe 40, which is connected to the output end 102 of the catalytic chamber 10; a fan mechanism 50, which is arranged on the exhaust gas output pipe 40, and is used to generate an airflow from the exhaust gas inlet pipe 20 to the exhaust gas output pipe 40; and a testing mechanism, which is arranged at the exhaust gas output pipe 40, and is used to test the exhaust gas discharged from the exhaust gas output pipe 40.
[0040] Specifically, the staff first puts the catalytic material 80 to be tested into the catalytic chamber 10; then, the exhaust gas is input into the exhaust gas inlet 201. At the same time, the fan mechanism 50 works to generate wind flow from the exhaust gas input pipe 20 to the exhaust gas output pipe 40, guiding the exhaust gas to pass through the heating mechanism 30 and then enter the interior of the catalytic chamber 10 through the input end 101, and then flow out of the catalytic chamber 10 from the output end 102 and be discharged through the exhaust gas output pipe 40. The testing mechanism tests the exhaust gas discharged from the exhaust gas output pipe 40, thereby obtaining various data of the exhaust gas after being treated by the catalytic material 80, so as to better understand the various performances of the currently tested catalytic material 80 and to carry out subsequent research and development or debugging.
[0041] Among them, when the exhaust gas passes through the heating mechanism 30, the heating mechanism 30 can heat the exhaust gas and effectively control the temperature of the exhaust gas, so that the catalytic material 80 in the subsequent catalytic chamber 10 can catalytically treat the exhaust gas at different temperatures. The catalytic effect curve of the catalytic material 80 within a certain temperature range is also drawn in combination with the testing mechanism, so as to obtain the upper and lower limits of the catalytic temperature of the catalytic material 80, and at what temperature the best catalytic effect can be achieved.
[0042] Compared with the prior art, the present application innovatively sets up a test device for exhaust gas treatment catalytic material 80, which heats the exhaust gas in the exhaust gas inlet pipe 20 through a heating mechanism 30, effectively controls the temperature of the exhaust gas, and meets the different temperature requirements of the catalytic material 80 in the catalytic chamber 10, and the testing mechanism tests the exhaust gas discharged from the exhaust gas output pipe 40, thereby testing the catalytic effect of the catalytic material 80, the processing capacity of the highest concentration of VOC, the upper and lower limits of the catalytic temperature, and the activity of the catalytic material 80 under long-term use.
[0043] Regarding the testing mechanism, in this embodiment, the exhaust gas output pipe 40 is provided with an exhaust gas outlet 401; the testing mechanism includes an anemometer 61, which is disposed at the exhaust gas outlet 401. Specifically, the anemometer 61 measures the wind speed of the exhaust gas discharged from the exhaust gas outlet 401 and adjusts the speed of the fan mechanism 50 to simulate the wind speed of an actual exhaust system. This simulates the catalytic effect and wind resistance, providing a basis for the modification and analysis of the catalytic material 80. It also allows for experimental verification of the total hydrocarbon content that a single cubic catalytic material 80 can process.
[0044] Preferably, the fan mechanism 50 includes a variable frequency fan, so that on the basis of providing air collection, catalytic passage and exhaust power, the wind speed and wind resistance can be adjusted as needed.
[0045] Furthermore, the anemometer 61 is detachably connected via an anemometer bracket 62 , and the anemometer bracket 62 is connected adjacent to the fan mechanism 50 .
[0046] Furthermore, a bypass output branch pipe 402 is provided on the exhaust gas output pipe 40, and the bypass output branch pipe 402 is arranged close to the exhaust gas outlet 401; the bypass output branch pipe 402 is provided with an exhaust gas total hydrocarbon measuring port 403 and a branch pipe switch valve 404; the testing mechanism also includes a flue gas detector, which is arranged at the exhaust gas total hydrocarbon measuring port 403.
[0047] Specifically, when the branch pipe on-off valve 404 is opened, a portion of the exhaust gas from the exhaust gas output pipe 40 flows through the bypass output branch pipe 402 to the exhaust gas total hydrocarbon measurement port 403 as it flows toward the exhaust gas outlet 401, thereby being detected by the flue gas detector. Furthermore, this configuration allows the exhaust gas total hydrocarbon measurement port 403 to be at zero pressure or a slightly positive pressure, allowing the flue gas detector's built-in pump to extract the exhaust gas under zero or minimal pressure, thereby ensuring detection accuracy and protecting the detector's safety.
[0048] Preferably, the smoke detector is a handheld smoke detector.
[0049] In one embodiment, the exhaust gas treatment catalytic material 80 testing device also includes a bypass pipe 70 and a control valve assembly, the bypass pipe 70 has an air inlet end and an air outlet end, the air inlet end is connected to the exhaust gas input pipe 20, and the air outlet end is connected to the exhaust gas output pipe 40; under the selective action of the control valve assembly, the exhaust gas in the exhaust gas input pipe 20 flows into the exhaust gas output pipe 40 through the bypass pipe 70, or the exhaust gas in the exhaust gas input pipe 20 flows into the exhaust gas output pipe 40 through the catalytic chamber 10, so that the VOC concentration comparison value of the catalyzed and uncatalyzed exhaust gases can be measured simultaneously.
[0050] Specifically, when it is necessary to measure the VOC concentration of uncatalyzed exhaust gas, the control valve assembly is selected to cause the exhaust gas in the exhaust gas inlet pipe 20 to flow through the bypass pipe 70 into the exhaust gas outlet pipe 40. That is, the exhaust gas in the exhaust gas inlet pipe 20 flows directly into the exhaust gas outlet pipe 40 via the bypass pipe 70 without undergoing catalytic treatment in the catalyst chamber 10. In this case, the data measured by the testing mechanism is data for the uncatalyzed exhaust gas, including the VOC concentration of the uncatalyzed exhaust gas. However, when it is necessary to measure the VOC concentration of catalyzed exhaust gas, the control valve assembly is selected to cause the exhaust gas in the exhaust gas inlet pipe 20 to flow through the catalyst chamber 10 into the exhaust gas outlet pipe 40. In this case, the data measured by the testing mechanism is data for the catalyzed exhaust gas, including the VOC concentration of the catalyzed exhaust gas.
[0051] Furthermore, the control valve assembly includes a bypass passage control valve 71 and a catalytic passage control valve 1011. The bypass passage control valve 71 is disposed at the intake end, and the catalytic passage control valve 1011 is disposed at the input end 101. When it is necessary to measure the VOC concentration of the uncatalyzed exhaust gas, the bypass passage control valve 71 is opened and the catalytic passage control valve 1011 is closed, and the exhaust gas in the exhaust gas inlet pipe 20 flows into the exhaust gas output pipe 40 through the bypass pipe 70. When it is necessary to measure the VOC concentration of the catalyzed exhaust gas, the bypass passage control valve 71 is closed and the catalytic passage control valve 1011 is opened, and the exhaust gas in the exhaust gas inlet pipe 20 flows into the exhaust gas output pipe 40 through the catalytic compartment 10.
[0052] In other embodiments, the control valve assembly includes a three-way valve, which is switched to connect the exhaust gas inlet pipe 20 to the bypass pipe 70 or to connect the exhaust gas inlet pipe 20 to the catalytic compartment 10 .
[0053] In one embodiment, the catalytic chamber 10 includes a chamber 110 and a cover 120, wherein the cover 120 covers the chamber 110. A plurality of position-limiting brackets 111 are disposed within the chamber 110, and a catalytic space for placing the catalytic material 80 is formed between the position-limiting brackets 111. Specifically, a worker opens the cover 120 to place the catalytic material 80 to be tested into the catalytic space, and the position-limiting brackets 111 secure the catalytic material 80.
[0054] Furthermore, the number of the limiting brackets 111 is four, with two layers of limiting brackets 111 distributed above and below, respectively, so as to limit and fix the catalytic material 80 from the middle and upper parts. Furthermore, the amount of catalytic material 80 being measured can be changed by changing the thickness of the catalytic material 80 in the catalytic space.
[0055] In one embodiment, the housing 110 is provided with an input pipe 112 and an output pipe 113. The input pipe 112 is connected to the input end 101, and the output pipe 113 is connected to the output end 102. The input pipe 112 and the output pipe 113 are arranged correspondingly. It should be noted that the catalytic material 80 has holes. Generally speaking, exhaust gas entering through the input pipe 112 needs to pass through the holes before being discharged through the output pipe 113. This avoids passing through the gap between the edge catalytic material 80 and the catalytic housing 10, thereby ensuring the effectiveness of exhaust gas passing through the catalytic material 80.
[0056] In one embodiment, a pre-catalytic thermocouple 130 and a post-catalytic thermocouple 140 are provided in the catalytic chamber 10. The pre-catalytic thermocouple 130 is arranged close to the input pipe 112, and the post-catalytic thermocouple 140 is arranged close to the output pipe 113. The pre-catalytic thermocouple 130 and the post-catalytic thermocouple 140 are used to detect the temperature of the exhaust gas before and after the catalysis and display it in conjunction with the temperature control meter, so as to change the heating degree of the heating mechanism 30 according to the temperature data to ensure the effect of the catalytic material 80.
[0057] Furthermore, the pre-catalytic thermocouple 130 and the post-catalytic thermocouple 140 are detachably connected to the catalytic compartment 10. Specifically, a mounting hole is provided on the catalytic compartment 10, and the mounting hole matches the pre-catalytic thermocouple 130 and the post-catalytic thermocouple 140 so that the pre-catalytic thermocouple 130 and the post-catalytic thermocouple 140 can be installed on the mounting hole.
[0058] Furthermore, the mounting hole is designed to accommodate an L-shaped anemometer. To facilitate understanding of this technology, the mounting holes are defined as a pre-catalytic mounting hole and a post-catalytic mounting hole. When wind speed testing is required, the L-shaped anemometer is placed in the pre-catalytic mounting hole to measure wind speed data before passing through the catalytic material, while the L-shaped anemometer is placed in the post-catalytic mounting hole to measure wind speed data after passing through the catalytic material. This application provides more data for the development and modification of catalytic materials by measuring wind speed data before and after passing through the catalytic material, combined with the wind speed data measured at the exhaust outlet 401.
[0059] Preferably, the mounting hole is provided on the cover body 120 .
[0060] In one embodiment, the heating mechanism 30 includes a tubular heater; the exhaust gas inlet 201 is provided with an incoming gas temperature thermocouple 310 so as to obtain the heating temperature of the tubular heater in real time.
[0061] In one embodiment, the exhaust gas output pipe 40 includes a serpentine cooling section 410, which is located between the output end 102 of the catalytic chamber 10 and the fan mechanism 50, so that the exhaust gas can be cooled by the serpentine cooling section 410 to prevent high-temperature exhaust gas from affecting the operation of the detection mechanism.
[0062] Regarding the exhaust gas treatment catalytic material 80 test device, in addition to being used in exhaust gas treatment systems in production lines or workshops such as color coating lines, laminating lines and paint bucket cleaning plants, it can also be used in related units engaged in the manufacture or design of exhaust gas treatment systems and catalyst materials.
[0063] Exhaust gas can be collected and catalytically treated in some of the above-mentioned situations to determine the catalytic effect of the catalytic material 80, its ability to treat the highest concentration of VOC, the upper and lower limits of the catalytic temperature, and the activity test of the catalyst under long-term use, so as to test the performance of newly developed catalytic materials and provide reference for future engineering projects in terms of catalytic material type, filling amount, catalytic temperature control and windage control.
[0064] Since the present application uses a fan mechanism 50, it has an independent power mechanism and simple control, is easy to operate, occupies a small area, and is economical and applicable. It is one of the preferred auxiliary equipment for exhaust system modification projects or testing new catalytic materials 80 and collecting design data for designing online catalytic devices.
[0065] Through the above method, the present application can provide relevant data such as the catalytic effect of different catalytic materials 80 at different catalytic temperatures, the pressure drop or wind resistance generated by catalytic materials of different capacities, and the catalytic effect under different catalytic conditions, thereby providing parameters for the development of catalytic materials 80 or the design of new catalytic devices.
[0066] Based on the disclosure and teachings of the above description, those skilled in the art may also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and any modifications and variations of the present invention should also fall within the scope of protection of the claims of the present invention. In addition, although certain specific terms are used in this description, these terms are for convenience of description only and do not constitute any limitation to the present invention.
Claims
1. A test device for exhaust gas treatment catalytic materials, characterized in that: include: a catalytic compartment having an input end and an output end; an exhaust gas inlet pipe, which is connected to the input end of the catalytic chamber and is provided with an exhaust gas inlet port; a heating mechanism, which is provided on the exhaust gas inlet pipe and is used to heat the exhaust gas in the exhaust gas inlet pipe; an exhaust gas output pipe, which is connected to the output end of the catalytic chamber; a fan mechanism, which is provided on the exhaust gas output pipe and is used to generate a wind flow in a direction from the exhaust gas input pipe to the exhaust gas output pipe; A testing mechanism is arranged at the exhaust gas output pipe and is used to test the exhaust gas discharged from the exhaust gas output pipe.
2. The exhaust gas treatment catalytic material testing device according to claim 1, characterized in that: The exhaust gas output pipe is provided with an exhaust gas outlet; The testing mechanism includes an anemometer, which is arranged at the exhaust gas outlet.
3. The exhaust gas treatment catalytic material testing device according to claim 2, characterized in that: The exhaust gas output pipe is provided with a bypass output branch pipe, and the bypass output branch pipe is arranged close to the exhaust gas outlet; The bypass output branch pipe is provided with an exhaust gas total hydrocarbon measuring port and a branch pipe switch valve; The testing mechanism includes a smoke detector, which is arranged at the exhaust gas total hydrocarbon measuring port.
4. The exhaust gas treatment catalytic material testing device according to any one of claims 1 to 3, characterized in that: The exhaust gas treatment catalytic material testing device further includes a bypass pipe and a control valve assembly, wherein the bypass pipe has an air inlet end and an air outlet end, wherein the air inlet end is connected to the exhaust gas input pipe and the air outlet end is connected to the exhaust gas output pipe; Under the selective action of the control valve assembly, the exhaust gas in the exhaust gas inlet pipe flows into the exhaust gas outlet pipe through the bypass pipe, or, The exhaust gas in the exhaust gas input pipe flows into the exhaust gas output pipe through the catalytic chamber.
5. The exhaust gas treatment catalytic material testing device according to claim 4, characterized in that: The control valve assembly includes a bypass passage control valve and a catalytic passage control valve. The bypass passage control valve is arranged at the intake end, and the catalytic passage control valve is arranged at the input end.
6. The exhaust gas treatment catalytic material testing device according to claim 1, characterized in that: The catalytic box includes a box body and a cover body, and the cover body is covered on the box body; a plurality of limiting brackets are arranged in the box body, and a catalytic space for placing catalytic materials is formed between the plurality of limiting brackets.
7. The exhaust gas treatment catalytic material testing device according to claim 6, characterized in that: The compartment body is provided with an input pipe and an output pipe, the input pipe is connected to the input end, and the output pipe is connected to the output end; the input pipe and the output pipe are arranged correspondingly.
8. The exhaust gas treatment catalytic material testing device according to claim 7, characterized in that: A pre-catalytic thermocouple and a post-catalytic thermocouple are provided in the catalytic chamber. The pre-catalytic thermocouple is arranged close to the input pipe, and the post-catalytic thermocouple is arranged close to the output pipe.
9. The exhaust gas treatment catalytic material testing device according to claim 1, characterized in that: The heating mechanism includes a tubular heater; the exhaust gas inlet is provided with an incoming gas temperature thermocouple.
10. The exhaust gas treatment catalytic material testing device according to claim 1, characterized in that: The exhaust gas output pipe includes a serpentine cooling section, and the serpentine cooling section is located between the output end of the catalytic chamber and the fan mechanism.