Temperature control heat recovery type flue gas CO removal device

Abstract

The utility model belongs to the technical field of flue gas treatment and environmental protection, and particularly relates to a temperature control heat recovery type flue gas CO removal device which is characterized by comprising a flue gas standby heater, a flue gas pretreatment unit, a catalytic reaction unit, a solid waste recovery unit and a heat recovery temperature control system. A diffused gas induced draft fan is used as a power source, and smoke flows along the device from bottom to top and then is discharged to a chimney; the catalytic reaction unit comprises an upper bed layer and a lower bed layer, a first heat recovery layer is arranged behind the first catalytic bed layer, a second heat recovery layer is arranged behind the second catalytic bed layer, and each catalytic bed layer is filled with a plurality of layers of honeycomb type catalysts. The device has the beneficial effects that multi-layer catalysis, intelligent temperature control and no pollutant generation and leakage are realized, the configuration number and form of the catalytic beds can be flexibly adjusted according to the CO content in the flue gas, meanwhile, the reaction heat in the flue gas is further recycled, and finally, the cooperative treatment of pollution reduction and carbon removal is realized.

Description

Technical Field

[0001] The utility model belongs to the technical field of flue gas treatment and environmental protection, and in particular relates to a temperature-controlled heat recovery type flue gas CO removal device. Background Art

[0002] The dry coke quenching technology is a technology that uses inert gas to extinguish red coke in a closed system, while processing and recovering flue gas dust and waste heat. During the operation of the dry coke quenching device, CO, H2 and SO2 will be continuously produced. The above pollutants will continue to accumulate in the circulating nitrogen and endanger the safe operation of the equipment. Therefore, about 10% of the circulating nitrogen must be released. This part of the gas is called the released flue gas. The released flue gas is discharged continuously, with a CO volume ratio of about 5% and a flue gas temperature of about 165°C. This part of CO is suitable for the technical route of catalytic oxidation. However, the inlet flue gas temperature of the catalytic reaction needs to reach about 180°C, and the reaction temperature rises too quickly, which will affect the catalytic efficiency and catalyst activity.

[0003] The utility model of application No. 202222764302.9 relates to a system for the coordinated treatment of SO2 and CO in low-temperature flue gas, including a heat exchanger, a desulfurization tower, a dust collector, a CO catalytic oxidation device and a fan. The heat exchanger consists of a flue gas heat exchange section and a clean flue gas heat exchange section. The CO catalytic oxidation device consists of two independent first reaction units and a second reaction unit. This scheme realizes the removal of CO and SO2, but there are the following problems: ① The flue gas to be treated is preheated by an air-to-air heat exchanger, which leads to a complex system, high system resistance and high operating cost; ② The system requires a high starting temperature. When the system is just started, heat must be supplemented by a hot air furnace to raise the flue gas temperature to above the catalyst activity temperature, which increases the safety hazards of the system; ③ The catalyst reactor design is difficult to meet the process requirements. The design only adopts a single, single-layer catalyst form, resulting in low system efficiency and life, high catalyst activation temperature, and when the oxidation temperature rises too high, it is easy to cause catalyst sintering damage. ④ This technology does not effectively utilize the flue gas waste heat, and is only used for preheating the flue gas to be treated, resulting in heat waste.

[0004] The Chinese utility model patent with application number 202311221909.5 discloses a method, system and graded catalytic reactor for treating flue gas commonly used in dry coke quenching. The treatment method includes: pretreatment and catalytic oxidation of CO and H2. The graded catalytic reactor includes: an oxygen activation layer, which is used to activate oxygen molecules and water molecules, and the flue gas first passes through the oxygen activation layer; a catalyst layer, the flue gas activated by the oxygen activation layer enters the catalyst layer, which is used for catalytic oxidation of CO and H2; a temperature regulating layer, and the temperature regulating layer is used to recover the heat in the catalytic oxidation reaction and adjust the temperature in the reactor. A part of the high-temperature clean flue gas is used to improve the catalytic reaction efficiency of CO and H2, and the other part is used for waste heat recovery to save energy. The graded catalytic reactor reduces the catalytic reaction temperature of CO and H2, effectively avoiding the problem of catalyst sintering damage caused by excessive catalytic reaction temperature. The scheme adopts a configuration of catalytic temperature from low to high to achieve the utilization of catalytic reaction heat. The disadvantage is that the series structure limits its application, and there is a problem of unstable catalytic efficiency for the changing CO and H2 content in the flue gas. Utility Model Content

[0005] The purpose of the utility model is to provide a temperature-controlled heat recovery flue gas CO removal device, which overcomes the shortcomings of the prior art and can be used in conjunction with a flue gas desulfurization and dust removal device. Each catalytic bed can work independently or in series, and can be flexibly adjusted according to the CO content in the flue gas. At the same time, the reaction heat in the flue gas can be further recovered and utilized, ultimately achieving coordinated pollution reduction and carbon removal.

[0006] To achieve the above purpose, the utility model is implemented through the following technical solutions:

[0007] A temperature-controlled heat recovery flue gas CO removal device, characterized in that it includes a flue gas standby heater, a flue gas pretreatment unit, a catalytic reaction unit, a solid waste recovery unit and a heat recovery temperature control system. The device is arranged after the flue gas desulfurization and dust removal device, and the above-mentioned units are vertically integrated, with a diffused air induced draft fan as a power source, and the flue gas flows from bottom to top along the device and is discharged to the chimney; the catalytic reaction unit is composed of two upper and lower beds, a first heat recovery layer is arranged behind the first catalytic bed layer, and a second heat recovery layer is arranged behind the second catalytic bed layer, and each catalytic bed layer is filled with multiple layers of honeycomb catalysts.

[0008] Furthermore, the flue gas backup heater is an electric heater or a gas hot air heater.

[0009] Furthermore, a multi-layer hollow plate structure is provided inside the flue gas pretreatment unit, adjacent plates are arranged at equal distances, and heat transfer oil flows through the plates.

[0010] Furthermore, the exterior of the catalytic reaction unit is entirely insulated.

[0011] Furthermore, the heat recovery temperature control system includes a thermal oil coil, an oil pump, a filter, an electric valve, a temperature measuring point, a flow measuring point and a pressure measuring point. The thermal oil coil is arranged in each heat recovery layer, and the thermal oil coil is connected to the oil pump through pipelines. Each pipeline is provided with an electric valve, a temperature measuring point and / or a flow measuring point and / or a pressure measuring point.

[0012] Furthermore, the pipeline in the heat recovery temperature control system is also connected to the plate heat exchanger in the flue gas pretreatment unit, and the plate heat exchanger is provided with a pretreatment electric valve and a temperature measuring point.

[0013] Furthermore, a flue gas CO concentration monitoring instrument and an air introduction device are provided at the inlet of the device.

[0014] Furthermore, the solid waste recovery unit is located at the bottom of the device, including a dust collection box or a screw conveyor.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] 1) The utility model provides a feasible solution for the catalytic removal of CO in flue gas, which can be used in conjunction with a flue gas desulfurization and dust removal device. Each catalyst bed can work independently or in series, with multi-layer catalysis and intelligent temperature control, without pollutant generation and leakage. The number and form of the catalyst beds can be flexibly adjusted according to the CO content in the flue gas, while further recycling the reaction heat in the flue gas, ultimately achieving coordinated pollution reduction and carbon removal.

[0017] 2) The utility model has flexible process and high adaptability, and can be widely promoted and applied in other waste gas treatment fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of an embodiment of the utility model.

[0019] In the figure: 1- flue gas standby heater, 2- flue gas pretreatment unit, 3- catalytic reaction unit, 4- solid waste recovery unit, 5- chimney, 6- heat transfer oil coil, 7- oil pump, 8- filter, 9- plate heat exchanger, 31- first catalytic bed, 32- first heat recovery layer, 33- second catalytic bed, 34- second heat recovery layer. DETAILED DESCRIPTION

[0020] The technical solution of the present utility model will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present utility model, rather than all of the embodiments.

[0021] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the specific embodiments required to be used in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the specific embodiments described below are some implementation methods of the utility model. For ordinary technicians in this field, other specific embodiments can be obtained based on these specific embodiments without paying creative work.

[0022] The components of the embodiments of the present invention generally described and shown in the specific embodiments herein can be arranged and designed in countless different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the specific embodiments is not intended to limit the scope of the utility model claimed, but only represents the selected embodiments of the utility model.

[0023] See Figure 1 , is a schematic diagram of the structure of an embodiment of a temperature-controlled heat recovery flue gas CO removal device of the utility model, comprising a flue gas standby heater 1, a flue gas pretreatment unit 2, a catalytic reaction unit 3, a solid waste recovery unit 4 and a heat recovery temperature control system. The device is arranged after the flue gas desulfurization and dust removal device. The above-mentioned units are vertically integrated, with the exhaust air induced draft fan as the power source. The flue gas flows from bottom to top along the device and is discharged to the chimney 5; the catalytic reaction unit 3 is an upper and lower bed layer, a first heat recovery layer 32 is arranged behind the first catalytic bed layer 31, and a second heat recovery layer 34 is arranged behind the second catalytic bed layer 33. Multiple layers of honeycomb catalysts are filled in each catalytic bed layer. The flue gas standby heater 1 can be an electric heater or a gas hot air heater. The exterior of the catalytic reaction unit 3 can be insulated as a whole.

[0024] The heat recovery temperature control system includes a heat transfer oil coil 6, an oil pump 7, a filter 8, and necessary electric valves, temperature measuring points, flow measuring points, and pressure measuring points. The heat transfer oil coil 6 is respectively arranged in the first heat recovery layer 32 and the second heat recovery layer 34. The heat transfer oil coil 6 is connected to the oil pump 7 through pipelines. A first recovery valve V2 is provided on the pipeline leading out of the first heat recovery layer 32, and a second recovery valve V3 is provided on the pipeline leading out of the second heat recovery layer 34.

[0025] The plate heat exchanger is provided with a pretreatment electric valve and a temperature measuring point. A plate heat exchanger 9 with a multi-layer hollow plate structure is provided inside the flue gas pretreatment unit 2. Adjacent plates are arranged at equal distances. Heat transfer oil is passed through the plates. The pipeline in the heat recovery temperature control system is also connected to the plate heat exchanger 9 in the flue gas pretreatment unit 2. The inlet of the temperature-controlled heat recovery flue gas CO removal device of the utility model is provided with a flue gas CO concentration monitoring instrument and an air introduction device.

[0026] The arrangement of instrument measuring points in the heat recovery temperature control system is as follows: Figure 1As shown, the flue gas inlet temperature is set at a measuring point T1, a pressure measuring point P1, a flow measuring point Q1, and a CO concentration measuring point W1. A temperature measuring point T2 is set at the end of the flue gas pretreatment unit. A temperature measuring point T3 is set at the outlet of the first catalytic bed layer 31, a temperature measuring point T4 is set at the outlet of the first heat recovery layer 32, and a temperature measuring point T5 is set at the outlet of the second catalytic bed layer 33. A temperature measuring point T6 is set at the outlet of the second heat recovery layer 34. The flue gas pretreatment unit 2 is also provided with a flow measuring point Q2, a flow measuring point Q3 is set on the branch of the first heat recovery layer 32, and a flow measuring point Q4 is set on the branch of the second heat recovery layer 34.

[0027] In the embodiment, the flue gas emitted by CDQ is about 165°C, and the flue gas temperature after desulfurization and dust removal is about 120°C, which is lower than the catalytic reaction window temperature of 180°C. When debugging the device, the flue gas standby heater 1 is first turned on to treat the flue gas pretreatment unit outlet temperature T2 to 180°C. After the system runs stably, the group flue gas standby heater 1 is turned off.

[0028] The temperature control mechanism of the heat recovery temperature control system is: for the flue gas pretreatment unit 2, if the flue gas inlet temperature T1 is less than 180°C, adjust the pretreatment electric valve V1 until the flue gas pretreatment unit outlet temperature T2 reaches 180°C, and the pretreatment electric valve V1 is used to adjust the heat transfer oil flow Q2 of the plate heat exchanger 9; the required first recovery layer heat transfer oil flow Q3 is calculated by the first catalytic bed outlet temperature T3, the first heat recovery layer temperature T4, and the inlet flue gas flow Q1, and the first recovery valve V2 is adjusted to make the first recovery layer heat transfer oil flow Q3 reach the set value; the required second recovery layer heat transfer oil flow Q4 is calculated by the second catalytic bed outlet temperature T5, the second heat recovery layer temperature T6, and the inlet flue gas flow Q1, and the second recovery valve V3 is adjusted to make the second recovery layer heat transfer oil flow Q4 reach the set value.

[0029] Taking 260000m3 / h flue gas as an example, the total volume of the catalyst is 40m 3 , honeycomb catalyst is filled in each catalytic bed. First, turn on the oil pump 7, fully open the valves V1, V2, and V3 on the heat transfer oil pipeline, and then open the inlet valve V4 to let the flue gas in. The temperature control system collects T2 to adjust V1 to control Q2, ensuring that T2 is around 180°C. The system collects T3 and T4 to adjust V2 to control Q3, ensuring that T4 is around 180°C, and the system collects T5T6 to adjust V3 to control Q4, ensuring that T6 is around 120°C. When the value of W1 is greater than 6%, open valve V4 to mix air in the air pipeline to dilute the flue gas.

[0030] The solid waste recovery unit 4 of the utility model is located at the bottom of the device, and is a dust collecting box or a screw conveyor.

[0031] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A temperature-controlled heat recovery flue gas CO removal device, characterized in that: It includes a flue gas standby heater, a flue gas pretreatment unit, a catalytic reaction unit, a solid waste recovery unit and a heat recovery temperature control system. The device is arranged after the flue gas desulfurization and dust removal device. The above units are vertically integrated and use the exhaust air induced draft fan as the power source. The flue gas flows from bottom to top along the device and is discharged to the chimney. The catalytic reaction unit consists of two upper and lower beds. A first heat recovery layer is arranged behind the first catalytic bed layer, and a second heat recovery layer is arranged behind the second catalytic bed layer. Each catalytic bed layer is filled with multiple layers of honeycomb catalysts.

2. A temperature-controlled heat recovery flue gas CO removal device according to claim 1, characterized in that: The flue gas standby heater is an electric heater or a gas hot air heater.

3. The temperature-controlled heat recovery flue gas CO removal device according to claim 1, characterized in that: The flue gas pretreatment unit is provided with a multi-layer hollow plate structure inside, adjacent plates are arranged at equal distances, and heat transfer oil flows through the plates.

4. A temperature-controlled heat recovery flue gas CO removal device according to claim 1, characterized in that: The exterior of the catalytic reaction unit is entirely heat-insulated.

5. The temperature-controlled heat recovery flue gas CO removal device according to claim 1, characterized in that: The heat recovery temperature control system includes a thermal oil coil, an oil pump, a filter, an electric valve, a temperature measuring point, a flow measuring point and a pressure measuring point. The thermal oil coil is arranged in each heat recovery layer. The thermal oil coil is connected to the oil pump through pipelines. Each pipeline is provided with an electric valve, a temperature measuring point and / or a flow measuring point and / or a pressure measuring point.

6. A temperature-controlled heat recovery flue gas CO removal device according to claim 5, characterized in that: The pipeline in the heat recovery temperature control system is also connected to the plate heat exchanger in the flue gas pretreatment unit, and the plate heat exchanger is provided with a pretreatment electric valve and a temperature measuring point.

7. The temperature-controlled heat recovery flue gas CO removal device according to claim 1, characterized in that: A flue gas CO concentration monitoring instrument and an air introduction device are installed at the inlet of the device.

8. The temperature-controlled heat recovery flue gas CO removal device according to claim 1, characterized in that: The solid waste recovery unit is located at the bottom of the device, with a dust collection box or a screw conveyor.

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