High-efficiency zero-short-circuit organic waste gas catalytic combustion device and treatment process thereof

Abstract

The invention belongs to the field of environmental protection equipment, and particularly relates to a high-efficiency zero-short-circuit organic waste gas catalytic combustion device and a treatment process thereof.The high-efficiency zero-short-circuit organic waste gas catalytic combustion device comprises a shell of a catalytic combustion chamber, the top of the shell is connected with a gas inlet mechanism, and the bottom of the shell is connected with an exhaust pipe; an air inlet grille mechanism, a non-noble metal catalysis mechanism, a first noble metal catalysis mechanism and a second noble metal catalysis mechanism which are used for uniformly conveying waste gas are sequentially arranged in the shell at intervals from top to bottom, and the air inlet grille mechanism is connected with an air inlet mechanism. According to the method, the device is applied, the problems of catalyst bed short circuit and the like of a traditional catalytic combustion device are solved, overall heat energy gradient distribution, temperature field uniform distribution and airflow field uniform distribution are achieved, the catalyst utilization rate is increased, the catalyst poisoning risk is reduced, and finally the purposes of increasing the VOCs purification rate and achieving long-term stable operation are achieved.

Description

Technical Field

[0001] The present invention belongs to the field of environmental protection equipment, and in particular relates to a high-efficiency zero-short-circuit organic waste gas catalytic combustion device and a treatment process thereof. Background Art

[0002] Volatile organic compounds (VOCs) are very harmful to both the human body and the environment. When humans are exposed to VOCs for a long time, they are very likely to develop diseases, which affects human health. The "Comprehensive Control Plan for Volatile Organic Compounds in Key Industries" clearly requires that the waste gas treatment efficiency of industries such as petrochemicals and coatings be ≥90%.

[0003] There are many existing VOC treatment technologies, such as condensation, absorption, direct combustion, adsorption, and catalytic combustion. Catalytic combustion has become the mainstream choice due to its balance between energy consumption and purification efficiency. However, existing catalytic combustion devices still have the following technical defects in the VOC treatment process: (1) Traditional catalytic combustion devices have problems such as uneven airflow distribution between multi-layer catalyst beds, local overheating leading to catalyst sintering, and insufficient catalyst utilization in the edge areas, which leads to short circuits in the catalyst bed and a decrease in VOCs conversion rate (generally <90%). (2) When precious metal catalysts are directly loaded into the catalytic combustion device, certain components in the exhaust gas may poison the catalyst; (3) Currently, the catalytic combustion chamber is equipped with a single-stage bed, and its catalyst is usually thicker. The VOCs concentration at the exhaust gas inlet is high, and the exhaust gas reacts quickly with the catalyst near the top. When entering the bottom catalyst, the exhaust gas concentration is too low, resulting in insufficient reaction driving force, low catalyst utilization and low VOCs conversion rate.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and propose a high-efficiency zero-short-circuit organic waste gas catalytic combustion device and its treatment process, which realizes the stepped distribution of thermal energy, uniform temperature field, and uniform airflow field, improves the catalyst utilization rate, reduces the risk of catalyst poisoning, and ultimately achieves the purpose of improving the VOCs purification rate and long-term stable operation.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: In one aspect, the present invention provides a high-efficiency zero-short-circuit catalytic combustion device for organic waste gas, comprising a housing for a catalytic combustion chamber, wherein the top of the housing is connected to an air intake mechanism, and the bottom is connected to an exhaust pipe. An air intake grille mechanism for uniformly transporting exhaust gas, a non-precious metal catalytic mechanism, a first precious metal catalytic mechanism, and a second precious metal catalytic mechanism are sequentially arranged in sequence from top to bottom within the housing, wherein the air intake grille mechanism is connected to the air intake mechanism; Among them, the air intake grille mechanism includes an air delivery component horizontally arranged inside the shell, and the air delivery component is composed of multiple pipes connected to form a grille structure. The air intake grille mechanism also includes multiple spiral nozzles evenly installed on each pipe. The branch pipe of the air intake mechanism passes through the shell and is connected to multiple pipes for evenly delivering exhaust gas into the shell.

[0007] Furthermore, the air intake mechanism includes a main pipe connected to the outer wall of the shell, and there are multiple branch pipes, all connected to the side of the main pipe.

[0008] Furthermore, the number of the branch pipes is 4, and the gas delivery assembly is composed of 4 pipes connected to form a tic-tac-toe structure, and a single branch pipe is connected to the corresponding intersection position of the tic-tac-toe structure below it.

[0009] Furthermore, a regulating valve is installed on each branch pipe, and any regulating valve is linked to a corresponding thermocouple installed at the lower part of the shell through a control system, and the thermocouple is located below the second precious metal catalyst mechanism.

[0010] Furthermore, the non-precious metal catalytic mechanism is provided with a non-metallic catalyst layer, a first fixed bed support net and a first cyclone plate in sequence from top to bottom, and the first fixed bed support net and the first cyclone plate are both connected to the inner wall of the shell.

[0011] Furthermore, the first swirl plate adopts an axial spiral blade structure.

[0012] Furthermore, the non-metallic catalyst layer includes at least one layer of catalyst modules covered with a first fixed bed support mesh, and the catalyst modules are formed by paving a honeycomb-shaped non-precious metal catalyst.

[0013] Furthermore, the first noble metal catalytic mechanism and the second noble metal catalytic mechanism have the same structure; The first precious metal catalyst mechanism includes a first precious metal catalyst layer, a second fixed bed support net and a second cyclone plate arranged in sequence from top to bottom, and the second fixed bed support net and the second cyclone plate are both connected to the inner wall of the shell.

[0014] Furthermore, a manhole is provided on the outer wall of the shell, and the manholes are all located above the non-precious metal catalytic mechanism, the first precious metal catalytic mechanism and the second precious metal catalytic mechanism.

[0015] On the other hand, the present invention also provides a treatment process for a high-efficiency zero-short-circuit organic waste gas catalytic combustion device, based on the device as described above, comprising the following steps: Step 1: The waste gas to be treated is sent into multiple branch pipes through the main pipe of the air intake mechanism, and then the gas is evenly sent into the shell through the spiral nozzle through the air intake grid mechanism connected to the multiple branch pipes; Step 2: The waste gas to be treated undergoes catalytic combustion reaction through the non-precious metal catalytic mechanism, the first precious metal catalytic mechanism, and the second precious metal catalytic mechanism, and is then discharged through an exhaust pipe; Among them, during the process of step 1 and step 2, the thermocouple monitors the temperature of the area in real time and uploads the temperature to the control system. When the thermocouple detects that the temperature exceeds the set temperature, the control system controls the opening of the regulating valve above the thermocouple to reduce the amount of organic waste gas entering.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1) The present invention provides a high-efficiency, zero-short-circuit catalytic combustion device for organic waste gas. By setting an air intake grille mechanism in the shell, the waste gas is sprayed into the catalytic combustion chamber in multiple areas. In addition, by setting a regulating valve on each branch pipe of the air intake grille mechanism, the air intake is evenly distributed, thus solving the problem of catalyst bed short-circuiting caused by uneven exhaust gas distribution.

[0017] 2) The present invention provides a high-efficiency zero-short-circuit catalytic combustion device for organic waste gas. By providing a non-precious metal catalytic mechanism, a first precious metal catalytic mechanism, and a second precious metal catalytic mechanism, a 1+2 multi-stage mode is adopted. The front end is provided with a first stage of non-precious metal catalyst, and the rear two stages use precious metal catalysts. The hierarchical arrangement can achieve airflow redistribution on the one hand, and disperse the combustion heat on the other hand, to avoid overheating of the catalyst layer in the case of high-concentration organic waste gas. In detail, the problem of catalyst poisoning is solved by setting up a honeycomb non-precious metal catalyst, which preferentially adsorbs sulfide (H2S), halogen (Cl⁻), siloxane and other substances; The precious metal catalyst layer is arranged in two stages, with a temperature balancing zone in the middle (i.e., in the interval area between the two layers of precious metal catalyst, the exhaust gas can be fully mixed in the interval area through the guidance of the swirl plate, thereby achieving the effect of temperature balance). The reaction heat is distributed in multiple stages to control the temperature of each bed layer, avoiding the temperature rise of the single-stage bed layer, and the large amount of heat release leading to local overheating and catalyst sintering; at the same time, it avoids the problem of thick single-stage bed catalyst causing insufficient reaction driving force, low catalyst utilization and low VOCs conversion rate; in addition, it can reduce the airflow resistance of the equipment, reduce airflow scouring loss, prevent the catalyst carrier from breaking, and achieve a triple breakthrough of "high efficiency-low energy consumption-long life".

[0018] 3) This invention provides a high-efficiency, zero-short-circuit catalytic combustion device for organic waste gas. A swirl plate is installed beneath each catalyst bed stage. This creates a tangential velocity component in the airflow, which then diffuses radially through centrifugal force, redistributing the waste gas. This solves the problem of traditional straight-through airflow leading to velocity variations across the bed and insufficient catalyst utilization at the edges. The swirl plate utilizes axial spiral blades, resulting in low pressure drop and easy machining. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, serve to explain the principles of the invention.

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0021] Figure 1 This is a schematic structural diagram of the catalytic combustion device for organic waste gas according to the present invention; Figure 2 This is a top view of the catalytic combustion device for organic waste gas of the present invention; Figure 3 This is a partial structural diagram of the air intake grille mechanism in the organic waste gas catalytic combustion device of the present invention; Figure 4 This is a schematic diagram of the structure of the swirl plate in the organic waste gas catalytic combustion device of the present invention.

[0022] In the figure: 1 is a catalytic combustion chamber; 2 is an air intake mechanism; 3 is an exhaust pipe; 4 is a thermocouple; 5 is a manhole; 6 is a pressure transmitter; 11 is a shell; 12 is an air intake grille mechanism; 13 is a non-precious metal catalytic mechanism; 14 is a first precious metal catalytic mechanism; 15 is a second precious metal catalytic mechanism; 21 is a main pipeline; 22 is a branch pipe; 23 is a regulating valve; 121 is a gas transmission component; 122 is a spiral nozzle; 131 is a non-metallic catalyst layer; 132 is a first fixed bed support net; 133 is a first swirl plate; 141 is a first precious metal catalyst layer; 142 is a second fixed bed support net; 143 is a second swirl plate; 1211 is a pipeline. DETAILED DESCRIPTION

[0023] Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present invention. Rather, they are merely examples of arrangements consistent with certain aspects of the present invention as detailed in the appended claims.

[0024] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. Example

[0025] On the one hand, see Figures 1 to 4 The present invention provides a high-efficiency zero-short-circuit catalytic combustion device for organic waste gas, comprising a shell 11 of a catalytic combustion chamber 1, wherein the top of the shell 11 is connected to an air intake mechanism 2, and the bottom is connected to an exhaust pipe 3. The interior of the shell 11 is sequentially arranged from top to bottom with an air intake grille mechanism 12 for uniformly transporting the exhaust gas, a non-precious metal catalytic mechanism 13, a first precious metal catalytic mechanism 14, and a second precious metal catalytic mechanism 15. The air intake grille mechanism 12 is connected to the air intake mechanism 2; Among them, the air intake grille mechanism 12 includes an air delivery component 121 horizontally connected to the inside of the shell 11, and the air delivery component 121 is composed of multiple pipes 1211 connected to form a grille structure. The air intake grille mechanism 12 also includes multiple spiral nozzles 122 evenly installed on each pipe. The branch pipe 22 of the air intake mechanism 2 passes through the shell 11 and is connected to the multiple pipes 1211 for evenly delivering exhaust gas into the shell 11.

[0026] like Figure 2 As shown, the air intake mechanism 2 includes a main pipe 21 connected to the outer wall of the shell 11, and a plurality of branch pipes 22 are connected to the side of the main pipe 21 and communicated with it.

[0027] like Figure 3 As shown, the number of the branch pipes 22 is 4, and the gas delivery assembly 121 is composed of 4 pipes connected to form a tic-tac-toe structure. A single branch pipe 22 is connected to the corresponding intersection position of the tic-tac-toe structure below it. This position is optimal, and each pipe can be connected to the pipes in the horizontal and vertical directions at the same time; it can also be connected to a certain pipe, which is not limited here.

[0028] Specifically, in this embodiment, the main conduit 21 is welded to the upper portion of the catalytic combustion chamber 1, but serves only as a support channel and is not connected to the interior of the catalytic combustion chamber 1. Exhaust gas to be treated enters through the main conduit 21 and is diverted through four branch conduits 22. These branch conduits 22 pass through the top of the housing 11 and connect to the intersection of the crisscross conduits. The exhaust gas to be treated enters the crisscross conduits through the branch conduits 22 and is ultimately sprayed into the interior of the housing 11 through the spiral nozzle 42 for catalytic combustion.

[0029] like Figure 1 and 2 As shown, a regulating valve 23 is installed on each branch pipe 22 , and any regulating valve 23 is linked to a corresponding thermocouple 4 installed at the lower part of the shell 11 through a control system. The thermocouple 4 is located below the second precious metal catalyst mechanism 15 .

[0030] It should be noted that the control system is a PLC or DCS control system, which is existing technology and will not be described in detail here.

[0031] Specifically, in this embodiment, when a thermocouple 4 below the shell 11 detects that the temperature is too high, the PLC control system obtains the information and sends a control signal to the regulating valve 23 corresponding to the thermocouple 4 to control the opening of the regulating valve 23 (a pneumatic regulating valve may be optionally used), thereby reducing the flow of exhaust gas and avoiding the temperature in the area where the thermocouple 4 is located from being too high.

[0032] Furthermore, the non-precious metal catalytic mechanism 13 is provided with a non-metallic catalyst layer 131, a first fixed bed support mesh 132 and a first swirl plate 133 in sequence from top to bottom, and the first fixed bed support mesh 132 and the first swirl plate 133 are both welded to the inner wall of the shell 11.

[0033] Specifically, in this embodiment, the non-metallic catalyst layer 131 includes at least one layer of catalyst modules covered with a first fixed bed support mesh 132. The catalyst module is paved with a 100mm×100mm×50mm honeycomb non-precious metal catalyst. Each honeycomb non-precious metal catalyst is connected by a high-temperature sealing rope and a high-temperature sealant to ensure the sealing between adjacent catalysts.

[0034] like Figure 4 As shown, the first swirl plate 133 adopts an axial spiral blade structure to disperse the combustion heat and avoid overheating of the catalyst layer in the case of high-concentration organic waste gas.

[0035] Furthermore, the first noble metal catalytic mechanism 14 and the second noble metal catalytic mechanism 15 have the same structure and the same connection method with the housing 11; The first precious metal catalyst mechanism 14 includes a first precious metal catalyst layer 141 , a second fixed bed support mesh 142 , and a second swirl plate 143 arranged in sequence from top to bottom. The second fixed bed support mesh 142 and the second swirl plate 143 are both welded to the inner wall of the shell 11 .

[0036] like Figure 1 As shown, a manhole 5 is provided on the outer wall of the shell 11 , and the manhole 5 is located above the non-precious metal catalytic mechanism 13 , the first precious metal catalytic mechanism 14 and the second precious metal catalytic mechanism 15 .

[0037] Specifically, in this embodiment, the manhole 5 is communicated with the catalytic combustion chamber 1 , and the manhole 5 can be opened and closed for inspection and replacement of the catalyst to meet the requirements of entry and exit of the catalyst module.

[0038] Furthermore, a thermocouple 4 and a pressure transmitter 6 are installed on the outer wall of the shell 11, and the thermocouple 4 and the pressure transmitter 6 are located between the non-precious metal catalytic mechanism 13 and the first precious metal catalytic mechanism 14, and between the first precious metal catalytic mechanism 14 and the second precious metal catalytic mechanism 15.

[0039] Furthermore, the first precious metal catalyst layer 141 and the second precious metal catalyst layer of the second precious metal catalyst mechanism 15 each include at least one layer of catalyst modules, which cover the entire second fixed bed support mesh 142 and are specifically composed of multiple connected sub-catalyst modules. The number of catalyst module layers is determined by actual operating conditions.

[0040] Specifically, in this embodiment, the catalyst is installed in a modular manner, and the sub-catalyst modules included in the catalyst module are arranged in a staggered manner. High-temperature sealing ropes and high-temperature sealants are used to bond the staggered joints to ensure the sealing between the sub-catalyst modules.

[0041] Furthermore, a bursting hole is provided on the top of the shell 11, and a supporting structure is provided on the bottom for fixing or connecting with other equipment.

[0042] On the other hand, the present invention provides a treatment process for a high-efficiency zero-short-circuit organic waste gas catalytic combustion device, based on the above-mentioned device, comprising the following steps: Step 1: The waste gas to be treated is respectively sent into the multiple branch pipes 22 through the main pipe 21 of the air intake mechanism 2, and then the gas is evenly sent into the shell 11 through the spiral nozzle 122 through the air intake grille mechanism 12 connected to the multiple branch pipes 22; Step 2: The waste gas to be treated undergoes catalytic combustion reaction through the non-precious metal catalyst mechanism 13, the first precious metal catalyst mechanism 14, and the second precious metal catalyst mechanism 15, and is then discharged through the exhaust pipe 3; During steps 1 and 2, the thermocouple 4 monitors the temperature of the area in real time and uploads the temperature to the PLC control system. When the thermocouple 4 detects that the temperature exceeds 400°C, the PLC control system controls the opening of the regulating valve 23 above the thermocouple 4 to reduce the amount of organic waste gas entering.

[0043] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0044] It should be understood that the present invention is not limited to the above description and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A high-efficiency zero-short-circuit organic waste gas catalytic combustion device, characterized in that: A shell (11) comprising a catalytic combustion chamber (1), wherein the top of the shell (11) is connected to an air intake mechanism (2), and the bottom is connected to an exhaust pipe (3); an air intake grille mechanism (12) for uniformly transporting exhaust gas, a non-precious metal catalytic mechanism (13), a first precious metal catalytic mechanism (14), and a second precious metal catalytic mechanism (15) are sequentially arranged in sequence from top to bottom inside the shell (11); the air intake grille mechanism (12) is connected to the air intake mechanism (2); The air intake grille mechanism (12) comprises an air delivery assembly (121) horizontally arranged inside the housing (11), the air delivery assembly (121) being composed of a plurality of pipes (1211) connected to form a grille structure, the air intake grille mechanism (12) further comprising a plurality of spiral nozzles (122) uniformly mounted on each pipe, and the branch pipe (22) of the air intake mechanism (2) passes through the housing (11) and is in communication with the plurality of pipes (1211) for uniformly delivering exhaust gas into the housing (11).

2. The high-efficiency zero-short-circuit organic waste gas catalytic combustion device according to claim 1 is characterized in that: The air intake mechanism (2) comprises a main pipe (21), the main pipe (21) being connected to the outer wall of the housing (11), and a plurality of branch pipes (22) being connected to the side of the main pipe (21).

3. The high-efficiency zero-short-circuit organic waste gas catalytic combustion device according to claim 1 is characterized in that: The number of the branch pipes (22) is four, and the gas delivery assembly (121) is formed by four pipes connected to form a tic-tac-toe structure, with a single branch pipe (22) connected to a corresponding cross position of the tic-tac-toe structure below it.

4. The high-efficiency zero-short-circuit organic waste gas catalytic combustion device according to claim 2 is characterized in that: A regulating valve (23) is installed on each branch pipe (22), and any regulating valve (23) is linked to a corresponding thermocouple (4) installed at the lower part of the shell (11) through a control system, and the thermocouple (4) is located below the second precious metal catalyst mechanism (15).

5. The high-efficiency zero-short-circuit organic waste gas catalytic combustion device according to claim 1 is characterized in that: The non-precious metal catalytic mechanism (13) is provided with a non-metallic catalyst layer (131), a first fixed bed support net (132) and a first cyclone plate (133) in sequence from top to bottom, and the first fixed bed support net (132) and the first cyclone plate (133) are both connected to the inner wall of the shell (11).

6. The high-efficiency zero-short-circuit organic waste gas catalytic combustion device according to claim 5 is characterized in that: The first swirl plate (133) adopts an axial spiral blade structure.

7. The high-efficiency zero-short-circuit organic waste gas catalytic combustion device according to claim 5 is characterized in that: The non-metallic catalyst layer (131) comprises at least one layer of catalyst modules covered with a first fixed bed support mesh (132), wherein the catalyst modules are formed by paving a honeycomb-shaped non-precious metal catalyst.

8. The high-efficiency zero-short-circuit organic waste gas catalytic combustion device according to claim 1 is characterized in that: The first noble metal catalytic mechanism (14) and the second noble metal catalytic mechanism (15) have the same structure; The first noble metal catalyst mechanism (14) comprises a first noble metal catalyst layer (141), a second fixed bed support net (142) and a second swirl plate (143) arranged in sequence from top to bottom, and the second fixed bed support net (142) and the second swirl plate (143) are both connected to the inner wall of the shell (11).

9. The high-efficiency zero-short-circuit organic waste gas catalytic combustion device according to claim 1 is characterized in that: A manhole (5) is provided on the outer wall of the shell (11), and the manholes (5) are all located above the non-precious metal catalytic mechanism (13), the first precious metal catalytic mechanism (14), and the second precious metal catalytic mechanism (15).

10. A treatment process for a high-efficiency zero-short-circuit organic waste gas catalytic combustion device, characterized in that: The device according to any one of claims 1 to 9 comprises the following steps: Step 1: The waste gas to be treated is respectively sent into a plurality of branch pipes (22) through the main pipe (21) of the air intake mechanism (2), and then the gas is uniformly sent into the housing (11) through the spiral nozzle (122) through the air intake grid mechanism (12) connected to the plurality of branch pipes (22); Step 2: the waste gas to be treated undergoes a catalytic combustion reaction through the non-precious metal catalytic mechanism (13), the first precious metal catalytic mechanism (14), and the second precious metal catalytic mechanism (15), and is then discharged through the exhaust pipe (3); During step 1 and step 2, the thermocouple (4) monitors the temperature of the area in real time and uploads the temperature to the control system. When the thermocouple (4) detects that the temperature exceeds the set temperature, the control system controls the opening of the regulating valve (23) above the thermocouple (4) to reduce the amount of organic waste gas entering.

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