A flue gas desulfurization and denitrification device

Abstract

The present invention discloses a flue gas desulfurization and denitrification device, which includes a desulfurization tower. A smoke exhaust pipe is connected to the bottom side wall of the desulfurization tower, and a first conveying pipe is connected to the top side wall. A temperature sensor is provided on the inner wall of the smoke exhaust pipe. The outlet end of the first conveying pipe is connected to a dust collector, the outlet end of the dust collector is connected to a second conveying pipe, the outlet end of the second conveying pipe is connected to an SCR reactor, the outlet end of the SCR reactor is connected to an exhaust pipe, and a blower is provided on the exhaust pipe. An ammonia tank is also provided outside the desulfurization tower, which is correspondingly connected to the smoke exhaust pipe and the second conveying pipe through a first spray pipe and a second spray pipe. Valves are provided on both the first spray pipe and the second spray pipe, and both the valves and the temperature sensor are connected to a programmable controller. The present invention solves the technical problem of how to reduce the treatment cost and at the same time improve the treatment efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas purification treatment, and particularly relates to a flue gas desulfurization and denitrification device. Background Art

[0002] The flue gas generated by industrial production contains sulfur oxides and nitrogen oxides. If directly discharged into the atmosphere without treatment, it will cause a series of environmental problems such as acid rain, photochemical smog and greenhouse effect. Therefore, it is necessary to carry out desulfurization and denitrification treatment on the flue gas before emission. In order to avoid the blockage of the dust collector caused by the mixing of ammonia gas and flue gas with a temperature less than 320 degrees, the desulfurization and denitrification devices in the prior art all adopt the process of denitrification first and then desulfurization to purify the flue gas. Obviously, this not only makes the mixing time of flue gas and ammonia gas in all temperature ranges relatively short, resulting in low treatment efficiency, but also due to the existence of large particle impurities in the flue gas, the service life of the catalyst in the SCR reactor is short, thus leading to high treatment costs. Summary of the Invention

[0003] In view of the deficiencies in the background art, the present invention provides a flue gas desulfurization and denitrification device, and the technical problem to be solved is how to reduce the treatment cost and improve the treatment efficiency at the same time.

[0004] To solve the above technical problem, the present invention provides a flue gas desulfurization and denitrification device, including a desulfurization tower. A smoke exhaust pipe is connected to the bottom side wall of the desulfurization tower, and a first conveying pipe is connected to the top side wall of the desulfurization tower. A temperature sensor is provided on the inner wall of the smoke exhaust pipe. The outlet end of the first conveying pipe is connected to a dust collector. The outlet end of the dust collector is connected to a second conveying pipe. The outlet end of the second conveying pipe is connected to an SCR reactor. The outlet end of the SCR reactor is connected to an exhaust pipe. A fan is provided on the exhaust pipe. An ammonia tank is also provided outside the desulfurization tower, which is correspondingly connected to the smoke exhaust pipe and the second conveying pipe through a first spray pipe and a second spray pipe. Valves are provided on both the first spray pipe and the second spray pipe. The valves and the temperature sensor are both connected to a programmable controller.

[0005] In a preferred embodiment of the present invention, the valve is a flow control valve.

[0006] In a preferred embodiment of the present invention, the dust collector is a ceramic tube dust collector.

[0007] In a preferred embodiment of the present invention, the fan is a high-pressure centrifugal fan.

[0008] In a preferred embodiment of the present invention, the inner walls of the smoke exhaust pipe, the first conveying pipe and the second output pipe are all coated with a high-temperature corrosion-resistant layer.

[0009] In a preferred embodiment of the present invention, the thickness of the high-temperature corrosion-resistant layer is 175μm - 200μm.

[0010] In a preferred embodiment of the present invention, a heat-insulating layer is provided on the outer wall of the SCR reactor.

[0011] In a preferred embodiment of the present invention, a heat-insulating layer is provided on the outer wall of the exhaust pipe.

[0012] In a preferred embodiment of the present invention, heat-insulating layers are provided on the outer peripheries of the first conveying pipe and the second conveying pipe.

[0013] In a preferred embodiment of the present invention, a blanking level indicator connected to the programmable controller is further provided on the ammonia tank.

[0014] The beneficial effects of the present invention: The flue gas is purified through the process of first desulfurizing and then denitrifying, thereby eliminating the influence of large particulate impurities in the flue gas on the catalyst in the SCR reactor, effectively extending the service life of the catalyst; and by respectively arranging a nitrogen injection point before the desulfurization and dust removal step and after the desulfurization and dust removal step, and arranging a temperature sensor in the exhaust pipe, under the control of the programming controller, the flue gas with a temperature not less than 320 degrees is mixed with ammonia before the desulfurization and dust removal step, and the flue gas with a temperature less than 320 degrees is mixed with ammonia after the desulfurization and dust removal step, thereby improving the treatment efficiency without blocking the dust collector, and thus achieving the technical effects of reducing the treatment cost and simultaneously improving the treatment efficiency. Compared with the prior art, the treatment cost is low, the treatment efficiency is high, and the service life of the catalyst is extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of the present invention;

[0016] Explanation of the reference numerals in the figure: 1. Desulfurization tower, 2. Exhaust pipe, 3. First conveying pipe, 4. Temperature sensor, 5. Dust collector, 6. Second conveying pipe, 7. SCR reactor, 8. Exhaust pipe, 9. Fan, 10. First spray pipe, 11. Second spray pipe, 12. Ammonia tank, 13. Valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The following further describes the present invention in conjunction with the drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the embodiments given are not intended to limit the present invention.

[0018] Refer to Figure 1As shown: A flue gas desulfurization and denitrification device includes a desulfurization tower 1. A smoke exhaust pipe 2 is connected to the bottom side wall of the desulfurization tower 1, and a first conveying pipe 3 is connected to the top side wall. A temperature sensor 4 is provided on the inner wall of the smoke exhaust pipe 2. The outlet end of the first conveying pipe 3 is connected to a dust collector 5. The outlet end of the dust collector 5 is connected to a second conveying pipe 6. The outlet end of the second conveying pipe 6 is connected to an SCR reactor 7. The outlet end of the SCR reactor 7 is connected to an exhaust pipe 8. A fan 9 is provided on the exhaust pipe 8. Outside the desulfurization tower 1, there is also an ammonia tank 12 connected to the smoke exhaust pipe 2 and the second conveying pipe 6 respectively through a first spray pipe 10 and a second spray pipe 11. Valves 13 are provided on both the first spray pipe 10 and the second spray pipe 11. Both the valve 13 and the temperature sensor 4 are connected to a programmable controller. Through this structural setting, on the one hand, the purification process of the flue gas is to desulfurize first and then denitrify, thus eliminating the influence of large particulate impurities in the flue gas on the catalyst in the SCR reactor 7, effectively prolonging the service life of the catalyst, and achieving the technical effect of reducing the treatment cost; on the other hand, during use, the temperature sensor 4 monitors the temperature of the flue gas in real time and sends the monitored data to the programmable controller. The programmable controller compares the data with a preset temperature value. The preset temperature value in the programmable controller is 320 degrees. When the data is not less than the preset temperature value, the programmable controller controls the valve 13 on the first spray pipe 10 to open and the valve 13 on the second spray pipe 11 to close, so that ammonia is mixed with the flue gas before the desulfurization and dust removal steps; otherwise, the programmable controller controls the valve 13 on the first spray pipe 10 to close and the valve 13 on the second spray pipe 11 to open, so that ammonia is mixed with the flue gas after the desulfurization and dust removal steps, thus achieving the technical effect of improving the treatment efficiency without clogging the dust collector 5.

[0019] In a preferred embodiment of the present invention, the valve 13 is a flow control valve, and such a setting makes the amount of ammonia used controllable.

[0020] In a preferred embodiment of the present invention, the dust collector 5 is a ceramic tube dust collector 5, and such a setting effectively prolongs the service life of the dust collector 5.

[0021] In a preferred embodiment of the present invention, the fan 9 is a high-pressure centrifugal fan, and such a setting ensures the stability of the conveying.

[0022] In a preferred embodiment of the present invention, the inner walls of the smoke exhaust pipe 2, the first conveying pipe 3, and the second output pipe are all coated with a high-temperature corrosion-resistant layer, and the thickness of the high-temperature corrosion-resistant layer is 175μm - 200μm. Such a setting not only effectively prolongs the service life of the smoke exhaust pipe 2, the first conveying pipe 3, and the second output pipe, but also reduces the maintenance cost of the device.

[0023] In a preferred embodiment of the present invention, a heat-insulating layer is provided on the outer wall of the SCR reactor 7, a heat-insulating layer is provided on the outer wall of the exhaust pipe 8, and heat-insulating layers are provided on the outer circumferences of the first conveying pipe 3 and the second conveying pipe 6. Such a setting effectively reduces heat loss.

[0024] In a preferred embodiment of the present invention, a blanking level indicator connected to the programmable controller is further provided on the ammonia tank 12. Such a setting improves the convenience of use.

[0025] In summary, the present invention purifies the flue gas through a process of first desulfurizing and then denitrifying, thereby eliminating the influence of large-particle impurities in the flue gas on the catalyst in the SCR reactor 7 and effectively extending the service life of the catalyst; and by respectively arranging a nitrogen injection point before and after the desulfurization and dust removal steps and arranging a temperature sensor 4 in the exhaust pipe 2, under the control of the programmable controller, the flue gas with a temperature not less than 320 degrees is mixed with ammonia before the desulfurization and dust removal step, and the flue gas with a temperature less than 320 degrees is mixed with ammonia after the desulfurization and dust removal step, thereby improving the treatment efficiency without blocking the dust collector 5. Therefore, the present invention can reduce the treatment cost and at the same time improve the treatment efficiency, and has the advantages of low treatment cost, high treatment efficiency and long service life of the catalyst.

[0026] The above embodiments are only preferred embodiments given to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention. The protection scope of the present invention is subject to the claims.

Claims

1. A flue gas desulfurization and denitrification device, characterized in that, It includes a desulfurization tower. A smoke exhaust pipe is connected to the bottom side wall of the desulfurization tower, and a first conveying pipe is connected to the top side wall. A temperature sensor is provided on the inner wall of the smoke exhaust pipe. The outlet end of the first conveying pipe is connected to a dust collector. The outlet end of the dust collector is connected to a second conveying pipe. The outlet end of the second conveying pipe is connected to an SCR reactor. The outlet end of the SCR reactor is connected to an exhaust pipe. A fan is provided on the exhaust pipe. An ammonia tank is also provided outside the desulfurization tower and is correspondingly connected to the smoke exhaust pipe and the second conveying pipe through a first spray pipe and a second spray pipe. Valves are provided on both the first spray pipe and the second spray pipe. Both the valves and the temperature sensor are connected to a programmable controller. The temperature sensor monitors the temperature of the flue gas in real time and sends the monitored data to the programmable controller. The programmable controller compares the data with a preset temperature value. The preset temperature value in the programmable controller is 320 degrees. When the data is not less than the preset temperature value, the programmable controller controls the valve on the first spray pipe to open and the valve on the second spray pipe to close, so that ammonia is mixed with the flue gas before the desulfurization and dust removal steps. Otherwise, the programmable controller controls the valve on the first spray pipe to close and the valve on the second spray pipe to open, so that ammonia is mixed with the flue gas after the desulfurization and dust removal steps.

2. The flue gas desulfurization and denitrification device according to claim 1, wherein The valve is a flow control valve.

3. The flue gas desulfurization and denitrification device according to claim 1, characterized in that, The dust collector is a ceramic tube dust collector.

4. The flue gas desulfurization and denitrification device according to claim 1, characterized in that, The fan is a high-pressure centrifugal fan.

5. The flue gas desulfurization and denitrification device according to claim 1, wherein, Heat-resistant and corrosion-resistant layers are coated on the inner walls of the smoke exhaust pipe, the first conveying pipe, and the second conveying pipe.

6. The flue gas desulfurization and denitration device according to claim 5, wherein The thickness of the heat-resistant and corrosion-resistant layer is 175μm - 200μm.

7. The flue gas desulfurization and denitrification device according to claim 1, characterized in that, A heat preservation layer is laid on the outer wall of the SCR reactor.

8. The flue gas desulfurization and denitrification device according to claim 1, wherein A heat preservation layer is laid on the outer wall of the exhaust pipe.

9. The flue gas desulfurization and denitrification device according to claim 1, wherein Heat preservation layers are laid on the outer perimeters of the first conveying pipe and the second conveying pipe.

10. The flue gas desulfurization and denitrification device according to claim 1, characterized in that, A blanking level indicator connected to the programmable controller is also provided on the ammonia tank.

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