A vertical gas-fired molten salt heater and its exhaust gas treatment device

Abstract

This invention discloses a vertical gas-fired molten salt heater and its exhaust gas treatment device, comprising at least one exhaust gas treatment component. The exhaust gas treatment component includes a flue gas inlet pipe, an exhaust pipe, and a treatment pipe, which are connected and a reversing valve is installed at the connection point. The reversing valve is electrically connected to an electrical control box. A flow rate sensor is detachably installed inside the flue gas inlet pipe and is electrically connected to the electrical control box. The flue gas inlet pipe includes a detector fitted within it. A first heat insulation coating and a second heat insulation coating are sequentially arranged on the detector and the flue gas inlet pipe. A force sensor is installed inside the detector and connected to a detection rod. The detection rod sequentially passes through the detector, the first heat insulation coating, the second heat insulation coating, and the flue gas inlet pipe. A detection block is connected to one end of the detection rod located inside the flue gas inlet pipe. This invention has high heat transfer efficiency and strong practicality.

Description

Technical Field

[0001] This invention relates to the field of heating furnace technology, specifically a vertical gas-fired molten salt heating furnace and its exhaust gas treatment device. Background Technology

[0002] Currently, there are more than 30 key universities and research institutes in China engaged in the development of molten salt applications. Most of the molten salt heating furnaces they use are borrowed industrial boilers or computer simulation experiments, and they lack effective experimental equipment.

[0003] Currently, most universities in my country are located in key environmental protection areas, where safety and environmental protection requirements are extremely stringent. Molten salt heating furnaces operate at high temperatures, typically around 400-550℃; environmental protection requirements in key areas stipulate that dust levels must be ≤10g / m³, and the flue gas generated by the heating furnace must be tested and treated before being discharged.

[0004] Existing density sensors suffer from short lifespans due to the large temperature fluctuations of the flue gas generated by the heating furnace, and overheating during certain periods. Meanwhile, the unit price of density sensors is relatively high.

[0005] Therefore, there is an urgent need for a low-cost and practical vertical gas-fired molten salt furnace and its exhaust gas treatment device. Summary of the Invention

[0006] The purpose of this invention is to provide a vertical gas-fired molten salt heating furnace and its exhaust gas treatment device to solve the problem that existing dust detectors are expensive and impractical.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A vertical gas-fired molten salt heating furnace exhaust gas treatment device includes at least one exhaust gas treatment component. The exhaust gas treatment component includes a flue gas inlet pipe, an exhaust pipe, and a treatment pipe. The flue gas inlet pipe, the exhaust pipe, and the treatment pipe are connected and a reversing valve is provided at the connection point. The reversing valve is electrically connected to an electrical control box. A flow rate sensor is detachably installed in the flue gas inlet pipe and is electrically connected to the electrical control box. The flue gas inlet pipe includes a detector fitted onto the flue gas inlet pipe. A heat insulation coating I and a heat insulation coating II are sequentially arranged between the detector and the flue gas inlet pipe. A force sensor is installed inside the detector. The force sensor is connected to a detection rod. The detection rod sequentially passes through the detector, the heat insulation coating I, the heat insulation coating II, and the flue gas inlet pipe. A detection block is connected to one end of the detection rod located inside the flue gas inlet pipe.

[0008] Compared with the prior art, the beneficial effects of the present invention are as follows: by detecting the relative concentration of flue gas inside the flue gas inlet pipe through the detection block and the force sensor, the dust content in the flue gas can be calculated. By setting the detection rod, the force sensor can detect the dust content outside the flue gas inlet pipe. Furthermore, by using heat insulation coating one and heat insulation coating two for heat insulation, the operating temperature of the force sensor is reduced, and the service life of the force sensor is enhanced.

[0009] Preferably, the detection block includes at least a partial spherical arc surface and a plane that connects with the arc surface. The spherical arc surface of the detection block is provided with a mounting hole for accommodating the detection rod, and structural adhesive is disposed between the mounting hole and the detection rod.

[0010] Preferably, the force sensor is electrically connected to the electrical control box. The force sensor is used to detect the axial force F exerted on the detection block along the flue gas inlet pipe. The projected area of ​​the detection block along the axial direction of the flue gas inlet pipe is S. The flow velocity sensor measures the real-time flow velocity of the flue gas as V. The dust content in the flue gas can then be calculated using the following formula, as follows: F=ρSV 2 ρ=F / (SV 2 ) n=ρ-ρ 空 In the formula, ρ 空 The density of air mixed with SO2 and NO2 is given by n, where n is the dust content. When n is greater than 10g / m 3 When the reversing valve is activated, the flue gas is discharged into the treatment pipeline. When n is less than or equal to 10 g / m 3 At that time, the flue gas is discharged into the exhaust pipe.

[0011] Preferably, the ends of the flue gas inlet pipe and / or the treatment pipe are provided with connecting flanges.

[0012] Another object of the present invention is to provide a vertical molten salt heating furnace for laboratory use, characterized in that the vertical molten salt heating furnace is used to heat and generate flue gas that is introduced into a tail gas treatment device, including a burner, a furnace bottom, a radiant section, a convection section, a flue outlet, an outlet manifold, an inlet manifold, an explosion-proof door, a flue, and a vertical furnace body that provides support, wherein the furnace bottom is connected to the flue, the burner is connected to the furnace bottom, and the flue outlet is connected to the flue gas inlet pipe; The radiant section is equipped with a coil, which is connected to the outlet manifold. The convection section is equipped with a serpentine tube, which is connected to the inlet manifold and the coil. The rear flue of the serpentine tube is connected to the flue outlet.

[0013] Preferably, the rear flue of the serpentine tube is equipped with an explosion-proof door, and the rear flue of the serpentine tube is equipped with a high-temperature air preheater.

[0014] Preferably, the rear flue of the serpentine tube is equipped with an explosion-proof door, and the rear flue of the serpentine tube is equipped with a high-temperature air preheater.

[0015] Preferably, the inlet manifold is located at the top of the vertical furnace body, the outlet manifold is located at the bottom of the vertical furnace body, and the flue gas outlet is located at the bottom of the vertical furnace body.

[0016] Preferably, the coil and / or the snake tube are made of heat-resistant steel plate shell.

[0017] Preferably, the burner is a high-temperature, low-NOx gas burner.

[0018] The beneficial effects of the present invention by adopting the above technical solution are as follows: When the boiler is running, the hot flue gas generated by the burner combustion enters the convection section for heat exchange after radiative heat exchange, and then enters the high-temperature air preheater through the flue. After heat exchange, it enters the flue gas inlet pipe through the flue outlet. The high-efficiency low-NOx burner can meet the environmental protection requirements (SO2 / NO2) of key areas, and the system thermal efficiency can be increased by more than 12%. It has a small footprint and is easy to assemble. It has safe and reliable combustion control and explosion-proof measures, and personnel safety is guaranteed. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a vertical gas-fired molten salt heater; Figure 2 This is a schematic diagram of the structure of a vertical gas-fired molten salt heater exhaust gas treatment device; Figure 3 This is a cross-sectional view of the flue gas inlet pipe; Figure 4 This is a schematic diagram of the three-dimensional structure of the detection block.

[0020] In the diagram: 1. Furnace bottom; 2. Coil; 3. Convection section; 4. Inlet manifold; 5. Explosion-proof door; 6. Flue; 7. High-temperature air preheater; 8. Flue outlet; 9. Outlet manifold; 10. Flue gas inlet pipe; 101. Connecting flange; 102. Detection block; 102a. Mounting hole; 103. Detection rod; 11. Detector; 111. Force sensor; 12. Processing pipe; 13. Reversing valve; 14. Exhaust pipe; 15. Heat insulation coating one; 16. Heat insulation coating two; 17. Vertical furnace body. Implementation

[0021] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] In this document, terms such as "upper," "lower," "inner," and "outer" are established based on the positional relationships shown in the accompanying drawings. Depending on the drawings, the corresponding positional relationships may also change. Therefore, they should not be interpreted as an absolute limitation on the scope of protection. Moreover, relational terms such as "first" and "second" are only used to distinguish one component from another that has the same name, and do not necessarily require or imply any such actual relationship or order between these components.

[0023] Example 1 like Figure 2-4 As shown, a vertical gas-fired molten salt heating furnace exhaust gas treatment device includes at least one exhaust gas treatment component. The exhaust gas treatment component includes a flue gas inlet pipe 10, an exhaust pipe 14, and a treatment pipe 12. The flue gas inlet pipe 10, the exhaust pipe 14, and the treatment pipe 12 are connected, and a reversing valve 13 is provided at the connection point. The reversing valve 13 is electrically connected to an electrical control box. A flow rate sensor is detachably installed in the flue gas inlet pipe 10, and the flow rate sensor is electrically connected to the electrical control box. The flue gas inlet pipe 10 includes a detector 11 fitted into the flue gas inlet pipe 10. The detector 11 and the flue gas inlet pipe 10 are sequentially provided with a heat insulation coating 15 and a heat insulation coating 16. A force sensor 111 is installed inside the detector 11. The force sensor 111 is connected to a detection rod 103. The detection rod 103 passes through the detector 11, the heat insulation coating 15, the heat insulation coating 16, and the flue gas inlet pipe 10 in sequence. One end of the detection rod 103 located inside the flue gas inlet pipe 10 is connected to a detection block 102.

[0024] Specifically, the first heat insulation coating 15 is made of ceramic microbubble material, and the second heat insulation coating 16 is made of foam plastic. This double-layer insulation coating reduces manufacturing costs while ensuring heat insulation performance. One end of the detection rod 103 is located inside the detector 11, and the other end is inside the flue gas inlet pipe 10. It passes sequentially through the outer wall of the detector 11, the first heat insulation coating 15, the second heat insulation coating 16, and the outer wall of the flue gas inlet pipe 10. Gaps exist between the detector 11 and its outer wall, the first heat insulation coating 15, the second heat insulation coating 16, and the flue gas inlet pipe 10. The relative concentration of flue gas inside the flue gas inlet pipe 10 is detected by the detection block 102 and the force sensor 111, thereby calculating the dust content in the flue gas. The detection rod 103 allows the force sensor 111 to detect the dust content from outside the flue gas inlet pipe 10. Furthermore, the heat insulation coatings 15 and 16 reduce the operating temperature of the force sensor 111, extending its service life.

[0025] Furthermore, the detection block 102 includes at least a partial spherical arc surface and a flat surface connected to the arc surface. The spherical arc surface of the detection block 102 is provided with a mounting hole 102a for accommodating the detection rod 103. Structural adhesive is provided between the mounting hole 102a and the detection rod 103. The spherical arc surface is used to prevent dust from accumulating on the detection block 102 and affecting the detection accuracy.

[0026] Furthermore, the force sensor 111 is electrically connected to the control box. The force sensor 111 is used to detect the force F along the axial direction of the flue gas inlet pipe 10 on the detection block 102. The projected area of ​​the detection block 102 along the axial direction of the flue gas inlet pipe 10 is S. The flow velocity sensor measures the real-time flow velocity of the flue gas as V. The dust content in the flue gas can then be calculated using the following formula, as follows: F=ρSV 2 ρ=F / (SV 2 ) n=ρ-ρ 空 In the formula, ρ 空 The density of air mixed with SO2 and NO2 is given by n, where n is the dust content. When n is greater than 10g / m 3 When the reversing valve is activated, the flue gas is discharged into the treatment pipeline. When n is less than or equal to 10 g / m 3 At that time, the flue gas is discharged into the exhaust pipe.

[0027] In detail, the processing pipe 12 is connected to a processing chamber, and the processing method can be any one of electrostatic dust removal, static dust removal, or water mist dust removal. 空 The calculation formula needs to consider the densities of NO2 and SO2. The density of NO2 is 30 mg / m³. 3 The density of SO2 is 35 mg / m³. 3 The concentrations of NO2 and SO2 are set at maximum concentrations to ensure that the actual dust content is less than the detected content, thus guaranteeing the quality of the exhaust gas. Since the mass fractions of CO2 and O2 are not significantly different, the content of other components in the flue gas besides NO2 and SO2 is considered approximately the same as that of air. The electrical control box serves as the control terminal, receiving data and outputting action signals. It can be a PLC, DCS, or other control terminal capable of processing data. The relative density of the dust-laden flue gas is calculated using the flue gas impulse, and then compared with the density of the dust-free flue gas to calculate the dust concentration. This avoids using a density sensor to calculate the density and allows for detection outside the flue gas inlet pipe 10. Preferably, a temperature sensor is installed inside the flue gas inlet pipe 10 to further revise the calculation results using the thermal expansion coefficient and temperature of the flue gas, further improving detection accuracy.

[0028] Furthermore, the flue gas inlet pipe 10 and / or the treatment pipe 12 are provided with a connecting flange 101 at their ends. The flue gas inlet pipe 10 and / or the treatment pipe 12 are connected to other pipes through the connecting flange 101. Since the flue gas inlet pipe 10 is relatively short, the connection through the connecting flange 101 makes it easy to remove the flow rate sensor and other components during maintenance.

[0029] Example 2 In this embodiment, the parts that are the same as in Embodiment 1 are given the same reference numerals, and the same text descriptions are omitted.

[0030] like Figure 1 As shown, the present invention also discloses a laboratory vertical molten salt heating furnace, which is used to heat and generate flue gas that is introduced into the tail gas treatment device of claims 1-4. The furnace includes a burner, a furnace bottom 1, a radiation section, a convection section 3, a flue gas outlet 8, an outlet manifold 9, an inlet manifold 4, an explosion-proof door 5, a flue 6, and a vertical furnace body 17 that provides support. The furnace bottom 1 is connected to the flue 6, the burner is connected to the furnace bottom 1, and the flue gas outlet 8 is connected to the flue gas inlet pipe 10. The radiant section is equipped with a coil 2, which is connected to the outlet manifold 9. The convection section 3 is equipped with a serpentine tube, which is connected to the inlet manifold 4 and the coil 2. The rear flue of the serpentine tube is connected to the flue outlet 8.

[0031] Furthermore, the rear flue of the serpentine tube is equipped with an explosion-proof door 5, and the rear flue of the serpentine tube is equipped with a high-temperature air preheater 7.

[0032] Furthermore, the explosion-proof door 5 is a gravity-type explosion-proof door 5; the high-temperature air preheater 7 is a tubular high-temperature air preheater, which serves as a component for recovering waste heat at the tail end, thereby improving the system's thermal efficiency.

[0033] Furthermore, the inlet manifold 4 is located at the top of the vertical furnace body 17, the outlet manifold 9 is located at the bottom of the vertical furnace body 17, and the flue gas outlet 8 is located at the bottom of the vertical furnace body 17.

[0034] Furthermore, coil 2 and / or the serpentine coil are made of heat-resistant steel plate shell.

[0035] Furthermore, the burner is a high-temperature, low-NOx gas burner.

[0036] In detail, during the operation of the heating furnace, the hot flue gas generated by the burner combustion undergoes heat exchange in the radiant section, then enters the convection section 3 for further heat exchange, and then enters the high-temperature air preheater through the flue duct 6. After heat exchange, it enters the flue gas inlet pipe 10 through the outlet pipe 8. Molten salt enters the serpentine tube of the convection section 3 through the inlet manifold 4, enters the coil 2 of the radiant section through the intermediate manifold, and finally exits the heating furnace through the outlet manifold 9 to release heat to the heat-using equipment. Molten salt and high-temperature flue gas exchange heat in a counter-current manner throughout the entire process. The air preheater outlet produces 200°C hot air, and the high-efficiency, low-NOx burner can meet the environmental protection requirements of key areas, improving the system thermal efficiency by more than 8%. The air preheater outlet produces 300°C hot air, and the high-efficiency, low-NOx burner can meet the environmental protection requirements of non-key areas, improving the system thermal efficiency by more than 12%.

[0037] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A vertical molten salt heating furnace for laboratory use, characterized in that, It includes a burner, a furnace bottom (1), a radiant section, a convection section (3), a flue gas outlet (8), an outlet manifold (9), an inlet manifold (4), an explosion-proof door (5), a flue (6), and a vertical furnace body (17) that provides support. The furnace bottom (1) is connected to the flue gas outlet (6), the burner is connected to the furnace bottom (1), and the flue gas outlet (8) is connected to the flue gas inlet pipe (10). The radiant section is provided with a coil (2), which is connected to the outlet manifold (9). The convection section (3) is provided with a serpentine tube, which is connected to the inlet manifold (4) and the coil (2). The rear flue of the serpentine tube is connected to the smoke outlet (8). It also includes at least one exhaust gas treatment component, which includes a flue gas inlet pipe (10), an exhaust pipe (14) and a treatment pipe (12). The flue gas inlet pipe (10), the exhaust pipe (14) and the treatment pipe (12) are connected together, and a reversing valve (13) is provided at the connection point. The reversing valve (13) is electrically connected to an electrical control box. A flow rate sensor is detachably installed in the flue gas inlet pipe (10), and the flow rate sensor is electrically connected to the electrical control box. The flue gas inlet pipe (10) includes a detector (11) fitted into the flue gas inlet pipe (10). A heat insulation coating first (15) and a heat insulation coating second (16) are sequentially arranged between the detector (11) and the flue gas inlet pipe (10). A force sensor (111) is installed inside the detector (11). The force sensor (111) is connected to a detection rod (103). The detection rod (103) passes through the detector (11), the heat insulation coating first (15), the heat insulation coating second (16), and the flue gas inlet pipe (10) in sequence. A detection block (102) is connected to one end of the detection rod (103) located inside the flue gas inlet pipe (10). The detection block (102) includes at least a partial spherical arc surface and a plane connected to the arc surface. The spherical arc surface of the detection block (102) is provided with a mounting hole (102a) for accommodating the detection rod (103). Structural adhesive is provided between the mounting hole (102a) and the detection rod (103). The force sensor (111) is electrically connected to the electrical control box. The force sensor (111) is used to detect the axial force F of the detection block (102) along the flue gas inlet pipe (10). The projected area of ​​the detection block (102) along the axial direction of the flue gas inlet pipe (10) is S. The flow velocity sensor measures the real-time flow velocity of the flue gas as V. The dust content in the flue gas can then be calculated using the following formula. The specific calculation method is as follows: F = pSV 2 p = F / (SV 2 ) n = p - p 空 In the formula, ρ 空 The density of air mixed with SO2 and NO2 is given by n, where n is the dust content. When n is greater than 10 g / m 3 the reversing valve (13) activates the discharge of the fumes towards the treatment duct (12), when n is less than or equal to 10 g / m 3 the fumes are discharged towards the exhaust duct (14).

2. A vertical furnace for heating molten salts in a laboratory according to claim 1, characterized in that, The ends of the flue gas inlet pipe (10) and / or the treatment pipe (12) are provided with connecting flanges (101).

3. A vertical furnace for heating molten salts in a laboratory according to claim 1, characterized in that, The rear flue of the serpentine tube is equipped with an explosion-proof door (5) and a high-temperature air preheater (7).

4. A vertical furnace for heating molten salts in a laboratory according to claim 3, characterized in that The explosion-proof door (5) is a gravity-type explosion-proof door (5); the high-temperature air preheater (7) is a tubular high-temperature air preheater, which serves as a component for recovering residual heat at the tail end, thereby improving the thermal efficiency of the system.

5. A vertical furnace for heating molten salts in a laboratory according to claim 1, characterized in that, The inlet manifold (4) is located at the top of the vertical furnace body (17), the outlet manifold (9) is located at the bottom of the vertical furnace body (17), and the flue gas outlet (8) is located at the bottom of the vertical furnace body (17).

6. A vertical furnace for heating molten salts in a laboratory according to claim 1, characterized in that, The coil (2) and / or the snake tube are made of heat-resistant steel plate shell.

7. A vertical furnace for heating molten salts in a laboratory according to claim 1, characterized in that, The burner is a high-temperature, low-NOx gas burner.

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