JP2019022875A - Absorption liquid circulation system blockage and anticorrosion device of exhaust gas desulfurizer and exhaust gas desulfurizer - Google Patents

Abstract

To provide an absorption liquid circulation system blockage and anticorrosion device of an exhaust gas desulfurizer which prevents blockage and anticorrosion of a spray nozzle and a circulation line and can stably continue operation, and an exhaust gas desulfurizer.SOLUTION: An absorption liquid circulation system blockage and anticorrosion device of an exhaust gas desulfurizer includes: an absorption column 10; a circulation pump 20 which pumps an absorption liquid stored in a liquid storage part 14 of the absorption column 10; a circulation line 30 which circulates the absorption liquid pumped by the circulation pump 20; a spray nozzle 40 which is connected to the circulation line 30 and blows out the absorption liquid in the absorption column 10; and an oxidant feeder 50 which feeds an oxidant to the liquid storage part 14, and includes an air introduction system 60 which guides air to the spray nozzle 40 which prevents the absorption liquid from blowing out.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an absorption liquid circulation system blockage / corrosion prevention device and a flue gas desulfurization device of a flue gas desulfurization device.

In general, sulfur oxides (SO ₂ etc.) contained in the flue gas discharged from a coal fired boiler of a thermal power plant are absorbed and removed by a flue gas desulfurization device.

As the flue gas desulfurization apparatus, a wet type limestone-gypsum method occupies the mainstream, and among these, a spray nozzle method is often employed. The flue gas desulfurization apparatus adopting the spray nozzle system is configured to pump an absorption liquid using calcium carbonate (CaCO ₃ ) as an absorbent from a liquid reservoir of an absorption tower with a circulation pump, and from the spray nozzle to the absorption tower through a circulation line. The absorption liquid is ejected into the interior of the tank, and desulfurization is performed by gas-liquid contact between the flue gas and the absorption liquid.

  For example, Patent Document 1 shows a general technical level related to the flue gas desulfurization apparatus.

Japanese Utility Model Laid-Open No. 4-14127

  By the way, inside the absorption tower of the flue gas desulfurization apparatus as described above, mist containing solids and flue gas containing sulfur are present, but during normal operation of the absorption tower, spray nozzles and circulation lines Absorbent is in circulation. For this reason, it is difficult for the mist and smoke to enter inside the spray nozzle and the circulation line, and there is no fear that the scale is generated to cause clogging or corrosion. However, for example, when the absorbing liquid stops flowing due to a failure of the circulation pump, the mist or smoke enters the spray nozzle or the circulation line, which may cause the spray nozzle or the circulation line to be blocked or corroded.

  When the spray nozzle or the circulation line is blocked or corroded, it is necessary to clean or replace the spray nozzle or the circulation line, and there is a problem that it takes time and labor for the cleaning and replacement work and the cost is increased. .

  Incidentally, in Patent Document 1, a part of the absorption liquid in the liquid reservoir is extracted from the outlet side of the circulation pump, gypsum is separated by a gypsum separation device, and the return liquid from which the gypsum has been separated is placed in the upper part of the overflow pipe. It is described that the overflow pipe is prevented from being blocked by spraying from the attached spray nozzle. However, in the case of the one described in Patent Document 1, it is difficult to introduce the return liquid into the spray nozzle in a situation where the circulation pump is out of order. Moreover, the spray nozzle of patent document 1 is fundamentally different from the spray nozzle connected to the circulation line of the present invention.

  The present invention has been made in view of the above-described conventional problems, and prevents blockage and corrosion of the spray nozzle and the circulation line, and prevents the absorption liquid circulation system from clogging / corrosion of the flue gas desulfurization apparatus that can continue operation stably. The present invention intends to provide an apparatus and a flue gas desulfurization apparatus.

In order to achieve the above-described object, the absorption liquid circulation system blockage / corrosion prevention apparatus of the flue gas desulfurization apparatus of the present invention includes an absorption tower, a circulation pump that pumps up the absorption liquid stored in the liquid reservoir of the absorption tower, A circulation line for circulating the absorption liquid pumped up by the circulation pump, a spray nozzle connected to the circulation line for jetting the absorption liquid into the absorption tower, and an oxidant supply for supplying an oxidant to the liquid reservoir An absorption liquid circulation system blockage / corrosion prevention device of a flue gas desulfurization device,
An air introduction system that guides air to a spray nozzle from which the absorption liquid is not ejected can be provided.

In the absorption liquid circulation system blockage / corrosion prevention device of the flue gas desulfurization device, the oxidant supplier is an oxidant air blower that supplies air as an oxidant to the liquid reservoir.
The air introduction system is
The oxidized air blower;
An air discharge valve provided in an air discharge line branched from the outlet side of the oxidized air blower;
An air introduction line branched from the outlet side of the discharge valve and connected to the circulation line;
A switching valve provided at a branch point of the air introduction line;
And a purge valve provided in the air introduction line downstream from the switching valve.

  The absorption liquid circulation system blockage / corrosion prevention device of the flue gas desulfurization device may include a check valve provided in an air introduction line on the outlet side from the purge valve.

In the absorption liquid circulation system blockage / corrosion prevention apparatus of the flue gas desulfurization apparatus, a sensor for detecting the flow state of the absorption liquid in the circulation line;
And a controller that outputs a control signal to the switching valve and the purge valve based on the flow state of the absorption liquid detected by the sensor.

  In the absorption liquid circulation system blockage / corrosion prevention device of the flue gas desulfurization device, the sensor may be a pressure gauge provided in the circulation line.

  The sensor may be a flow meter provided in the circulation line.

In the absorbent circulation system blockage / corrosion prevention device of the flue gas desulfurization device, the air introduction system is:
An air supply line connectable to a wash water supply line connected to the circulation line;
An air supply blower for supplying air to the air supply line.

  In the absorption liquid circulation system blockage / corrosion prevention apparatus of the flue gas desulfurization apparatus, the spray nozzle may be provided with a reserve in which the absorption liquid is not ejected during normal operation of the absorption tower.

  Furthermore, it can also be set as the flue gas desulfurization apparatus provided with the said absorption liquid circulation system blockage | corrosion prevention apparatus.

  According to the absorption liquid circulation system blockage / corrosion prevention device and the flue gas desulfurization device of the flue gas desulfurization apparatus of the present invention, the excellent effect that the spray nozzle and the circulation line are blocked and corroded and the operation can be continued stably. Can be played.

It is a schematic block diagram which shows the 1st Example of the absorption liquid circulation system obstruction | occlusion and corrosion prevention apparatus of a flue gas desulfurization apparatus of this invention, and a flue gas desulfurization apparatus. It is a schematic block diagram which shows the 2nd Example of the absorption liquid circulation system obstruction | occlusion and corrosion prevention apparatus of a flue gas desulfurization apparatus of this invention, and a flue gas desulfurization apparatus. It is a schematic block diagram which shows the 3rd Example of the absorption liquid circulation system obstruction | occlusion and corrosion prevention apparatus of a flue gas desulfurization apparatus of this invention, and a flue gas desulfurization apparatus.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 shows a first embodiment of an absorption liquid circulation system blockage / corrosion prevention device and a flue gas desulfurization device of the flue gas desulfurization device of the present invention.

  The flue gas desulfurization apparatus shown in FIG. 1 includes an absorption tower 10, a circulation pump 20, a circulation line 30, a spray nozzle 40, and an oxidant supplier 50.

The absorption tower 10 includes a tower main body 11 extending in the vertical direction, and a flue gas inlet 12 is formed at a required height position on a side surface of the tower main body 11. An outlet 13 is formed. An absorption liquid reservoir 14 is formed inside the tower body 11 below the inlet 12. Note that calcium carbonate (CaCO ₃ ) is used as the absorbent of the absorbent.

  The circulation pump 20 is a pump that pumps up the absorbent stored in the liquid reservoir 14 of the absorption tower 10. Although two circulation pumps 20 shown in FIG. 1 are provided, the number of circulation pumps 20 may be singular or may be three or more.

  One end of the circulation line 30 is connected to the bottom of the tower body 11 of the absorption tower 10 so as to communicate with the liquid reservoir 14 and rises upward, and the other end extends through the side surface of the tower body 11 to the inside. It is arranged so that. The circulation pump 20 is provided in the middle of the circulation line 30, and the absorption liquid in the liquid reservoir 14 pumped up by the circulation pump 20 is circulated from the circulation line 30 to the absorption tower 10. The circulation line 30 shown in FIG. 1 has one end connected to the bottom of the tower main body 11 of the absorption tower 10 and is connected to the other two pumping lines 31 and the other end of the two systems. A pumping header 32, a main line 33 that is connected to an intermediate portion of the pumping header 32 and rises upward, and three systems of spray headers 34 that branch from the upper part of the main line 33 and extend into the tower body 11. ing. The pumping line 31 is provided with the circulation pump 20 and the discharge valve 35, and the spray header 34 is provided with a shutoff valve 36.

  The spray nozzle 40 is connected to the circulation line 30 inserted into the tower main body 11 so as to be arranged at a predetermined interval in the longitudinal direction, and the absorbent is supplied to the interior of the absorption tower 10. To come out. The spray nozzle 40 shown in FIG. 1 is provided in the spray header 34 of the circulation line 30, and one of the three spray headers 34 is set as a spare to be used as needed.

  The oxidant supply unit 50 includes an oxidant air blower 51 that supplies air as an oxidant to the liquid reservoir 14. An oxidant supply line 52 that guides air as an oxidant to the liquid reservoir 14 is connected to the outlet side of the oxidizing air blower 51 of the oxidizing agent supplier 50 shown in FIG. An air discharge valve 54 is provided in the atmospheric discharge line 53 branched from the oxidant supply line 52. As the air discharge valve 54 stops due to a failure of the circulation pump 20, the amount of oxidized air to be supplied to the liquid reservoir 14 decreases, and the air sent to the oxidant supply line 52 by the oxidized air blower 51 is reduced. This is a valve that opens when the pressure or flow rate of the oxidant supply line 52 exceeds a set value and releases excess air. A stirrer 55 is provided in the vicinity of the outlet 52 a in the liquid reservoir 14 of the oxidant supply line 52 so that air as an oxidizer is uniformly mixed into the absorbent in the liquid reservoir 14. ing.

  In the case of the first embodiment, an air introduction system 60 that guides air to the spray nozzle 40 from which the absorbing liquid is not ejected is provided.

  The air introduction system 60 shown in FIG. 1 includes the oxidized air blower 51, an air discharge valve 54 provided in the atmospheric discharge line 53, an air introduction line 61, a switching valve 62, and a purge valve 63. ing.

  The air introduction line 61 is branched from the air release line 53 on the exit side of the air discharge valve 54 and connected to the circulation line 30. The upper part of the air introduction line 61 shown in FIG. 1 is branched as three air introduction branch pipes 61 a, and each of the air introduction branch pipes 61 a is connected to the upstream side of the shutoff valve 36 of the spray header 34.

  The switching valve 62 is a three-way valve provided at a branch point of the air introduction line 61. The three-way valve can be switched between an introduction position for introducing air to the air introduction line 61 when the discharge valve 54 is opened and a release position for releasing air to the atmosphere when the discharge valve 54 is opened. It has become.

  The purge valve 63 is provided in the air introduction line 61 on the downstream side of the switching valve 62. The purge valve 63 shown in FIG. 1 is provided in each of the three air introduction branch pipes 61a.

  Further, a check valve 64 is provided in the air introduction line 61 (air introduction branch pipe 61a) on the outlet side from the purge valve 63.

  Next, the operation of the first embodiment will be described.

During normal operation of the absorption tower 10, the circulation pump 20 is driven, and the absorption liquid in the liquid reservoir 14 flows through the circulation line 30 and is ejected from the spray nozzle 40 into the absorption tower 10 and circulates down to the liquid reservoir 14. The flue gas sent to the absorption tower 10 from a coal fired boiler or the like (not shown) is brought into gas-liquid contact with the absorbing liquid ejected from the spray nozzle 40, so that the sulfur oxide is absorbed and removed. Then, it is discharged from the outlet 13 of the absorption tower 10 to the outside. The absorption reaction at this time is
SO ₂ + CaCO ₃ + 1 / 2H ₂ O → CaSO ₃ · 1 / 2H ₂ O + CO ₂
It becomes. In addition, since the check valve 64 is provided in the air introduction line 61 (air introduction branch pipe 61a) on the outlet side from the purge valve 63, the absorption liquid is supplied to the air introduction line 61 during the normal operation of the absorption tower 10. There is no worry of backflow.

At the same time, from the oxidant air blower 51 of the oxidant supply device 50, air as the oxidant is supplied to the liquid reservoir 14 of the absorption tower 10 via the oxidant supply line 52, and the air is absorbed by the stirrer 55. The gypsum is produced as a by-product. The gypsum is extracted from the liquid reservoir 14 together with a part of the absorption liquid through a conduit (not shown) and collected. The oxidation reaction at this time is
CaSO ₃ · 1 / 2H ₂ O + 1 / 2O ₂ + 3 / 2H ₂ O → CaSO ₄ · 2H ₂ O
It becomes.

  During normal operation of the absorption tower 10, the absorbing liquid is circulated through the spray nozzle 40 and the circulation line 30. For this reason, it is difficult for mist and smoke containing solid content to enter the inside of the spray nozzle 40 and the circulation line 30, and there is no fear that scale will be generated and blockage will occur or corrosion will occur.

  On the other hand, if the absorption liquid stops flowing into the circulation line 30 due to a failure of the circulation pump 20, the mist and exhaust gas enter the spray nozzle 40 and the circulation line 30 as they are, and the spray nozzle 40 and There is a possibility that the circulation line 30 may be blocked or corroded. Here, when the circulation pump 20 fails and stops, the amount of oxidized air to be supplied to the liquid reservoir 14 for the oxidation reaction decreases, and the air sent to the oxidant supply line 52 by the oxidized air blower 51. Becomes a surplus, the pressure or flow rate of the oxidant supply line 52 exceeds the set value, the vent valve 54 opens, and the surplus air flows through the atmospheric discharge line 53. In this situation, when the switching valve 62, which is a three-way valve, is switched to the introduction position and the purge valve 63 is opened, excess air is guided from the air introduction line 61 to the spray header 34 of the circulation line 30 and blown out from the spray nozzle 40.

  Thereby, since air flows through the spray nozzle 40 and the circulation line 30, it becomes difficult for the mist and smoke to enter the inside of the spray nozzle 40 and the circulation line 30. It is possible to prevent scale from occurring inside the circulation line 30 and causing clogging or corrosion.

  If the spray nozzle 40 and the circulation line 30 are not blocked or corroded, the spray nozzle 40 and the circulation line 30 need not be cleaned or replaced, and the cleaning and replacement work does not take time and effort, and the cost increases. Can also be avoided.

  In addition, the ability to utilize the air that has been released to the atmosphere when the circulation pump 20 is stopped is effective in eliminating the waste of operation. Incidentally, it is conceivable to supply water or the like instead of air to the spray nozzle 40. However, when water or the like is supplied to the spray nozzle 40, the liquid level of the liquid reservoir 14 and the properties of the absorbing liquid change, and after the restoration, While there is a possibility that the operation may be hindered, if it is air, the liquid level of the liquid reservoir 14 and the properties of the absorption liquid are not affected, and the resumption of the operation can proceed smoothly.

  When the spray header 34 in the lowermost stage is set as a spare, the switching valve 62 that is a three-way valve is switched to the introduction position during normal operation of the absorption tower 10, and the air connected to the spray header 34 set as a spare is connected. Only the purge valve 63 of the introduction branch pipe 61a is opened so that air is supplied to the spare spray nozzle 40 when the vent valve 54 is opened, thereby preventing the spare spray nozzle 40 from being blocked or corroded. It is also possible to do.

  Thus, the spray nozzle 40 and the circulation line 30 are prevented from being blocked and corroded, and the operation can be continued stably.

  FIG. 2 is a second embodiment of the absorption liquid circulation system blockage / corrosion prevention device and the flue gas desulfurization device of the flue gas desulfurization apparatus of the present invention. In the figure, the same reference numerals as those in FIG. Represents.

  A feature of the second embodiment is that a sensor 70 that detects the flow state of the absorbent in the circulation line 30, and the switching valve 62 and the purge valve 63 based on the flow state of the absorbent detected by the sensor 70. And a controller 80 for outputting control signals 81 and 82.

  The sensor 70 is a pressure gauge 71 provided in the circulation line 30, and by detecting the pressure of the circulation line 30 with the pressure gauge 71, it is possible to determine the flow state of the absorbing liquid in the circulation line 30. In this case, the signal 70 a output from the sensor 70 becomes the pressure signal 71 a output from the pressure gauge 71.

  The sensor 70 may be a flow meter 72 provided in the circulation line 30, and the flow rate of the circulation line 30 may be detected by the flow meter 72 to determine the flow state of the absorbent in the circulation line 30. it can. In this case, the signal 70 a output from the sensor 70 becomes the flow signal 72 a output from the flow meter 72.

  Next, the operation of the second embodiment will be described.

  When the sensor 70 is a pressure gauge 71, the pressure of the circulation line 30 is detected by the pressure gauge 71, and a signal 70 a output from the sensor 70 is input to the controller 80 as a pressure signal 71 a output from the pressure gauge 71. Then, the flow state of the absorbent in the circulation line 30 is determined.

  When the sensor 70 is a flow meter 72, the flow rate of the circulation line 30 is detected by the flow meter 72, and the signal 70 a output from the sensor 70 is used as a flow rate signal 72 a output from the flow meter 72. And the flow state of the absorbent in the circulation line 30 is determined.

  When it is determined by the sensor 70 that the absorbing liquid is not flowing in the circulation line 30, the three-way valve is generated by the control signals 81 and 82 output from the controller 80 in a situation where excess air flows through the atmospheric discharge line 53. The switching valve 62 is switched to the introduction position and the purge valve 63 is opened, and excess air is guided from the air introduction line 61 to the spray header 34 of the circulation line 30 and blown out from the spray nozzle 40.

  Thus, in the case of the second embodiment, air is automatically circulated to the spray nozzle 40 and the circulation line 30 by the control signals 81 and 82 from the controller 80. It becomes difficult for mist and flue gas containing minute components to enter, and it is possible to prevent scales from occurring inside the spray nozzle 40 and the circulation line 30 to cause clogging and corrosion.

  When the spray nozzle 40 and the circulation line 30 are not blocked or corroded, the spray nozzle 40 and the circulation line 30 need not be cleaned or replaced in the second embodiment as in the first embodiment. The work does not take time and effort, and the cost can be avoided.

  Further, the fact that surplus air that has been released into the atmosphere when the circulating pump 20 is stopped can be utilized in the second embodiment as well, as in the first embodiment, in order to eliminate waste of operation. Incidentally, it is conceivable to supply water or the like instead of air to the spray nozzle 40. However, when water or the like is supplied to the spray nozzle 40, the liquid level of the liquid reservoir 14 and the properties of the absorbing liquid change, and after the restoration, In the case of air, the second embodiment may affect the liquid level of the liquid reservoir 14 and the properties of the absorbing liquid as well as the first embodiment. There is no need to restart the operation.

  When the spray header 34 in the lowermost stage is set as a spare, during the normal operation of the absorption tower 10, the switching valve 62, which is a three-way valve, is switched to the introduction position by the control signals 81 and 82 from the controller 80. Only the purge valve 63 of the air introduction branch pipe 61a connected to the spray header 34 set as a spare is opened so that air is supplied to the spare spray nozzle 40 when the air discharge valve 54 is opened. It is also possible to prevent the spare spray nozzle 40 from being blocked or corroded.

  Thus, also in the second embodiment, as in the first embodiment, the spray nozzle 40 and the circulation line 30 are prevented from being blocked and corroded, and the operation can be continued stably.

  FIG. 3 shows a third embodiment of the absorption liquid circulation system blockage / corrosion prevention device and the flue gas desulfurization device of the flue gas desulfurization device of the present invention. In the figure, the same reference numerals as those in FIG. Represents.

  A feature of the third embodiment is that, in the absorption tower 10 in which the existing wash water supply line 90 is connected to the circulation line 30, an air supply line 65 that can be connected to the wash water supply line 90, and the air The air introduction system 60 is configured from an air supply blower 66 for supplying air to the supply line 65.

  The cleaning water supply line 90 is provided with an opening / closing valve 91. Further, the air supply line 65 is connected to the cleaning water supply line 90 via the flange 92, but a one-touch type coupler or the like may be used.

  Next, the operation of the third embodiment will be described.

  If the absorption liquid stops flowing into the circulation line 30 due to a failure of the circulation pump 20, the air supply line 65 is connected to the existing wash water supply line 90 in the circulation line 30, and the on-off valve 91 is opened to open the air supply blower. When 66 is driven, air is guided from the air supply blower 66 to the spray header 34 of the circulation line 30 through the air supply line 65 and the washing water supply line 90 and blown out from the spray nozzle 40.

  Thus, in the case of the third embodiment, since air flows through the spray nozzle 40 and the circulation line 30 via the air supply line 65 and the washing water supply line 90, the solid content is present inside the spray nozzle 40 and the circulation line 30. It is difficult for mist and smoke exhausting to enter, and scale is generated inside the spray nozzle 40 and the circulation line 30 to prevent clogging and corrosion.

  When the spray nozzle 40 and the circulation line 30 are not blocked or corroded, the spray nozzle 40 and the circulation line 30 need not be cleaned or replaced in the third embodiment as in the first and second embodiments. In addition, it does not take time and effort for cleaning and replacement work, and the cost is avoided.

  Further, by using the existing cleaning water supply line 90 connected to the circulation line 30, it is not necessary to newly provide a dedicated nozzle or the like in the circulation line 30. The air supply line 65 is added to the cleaning water supply line 90. It is possible to cope with the simple work of just connecting. Incidentally, it is conceivable to supply water or the like instead of air to the spray nozzle 40. However, when water or the like is supplied to the spray nozzle 40, the liquid level of the liquid reservoir 14 and the properties of the absorbing liquid change, and after the restoration, In the case of air, in the case of air, the liquid level of the liquid reservoir 14 and the properties of the absorbing liquid are also the same as in the first and second embodiments. There is no effect, and resumption of operation can proceed smoothly.

  When the spray header 34 in the lowermost stage is set as a spare, air is supplied from the spray header 34 set as a spare to the spare spray nozzle 40 during normal operation of the absorption tower 10, thereby It is also possible to prevent the spare spray nozzle 40 from being blocked or corroded.

  Thus, in the third embodiment, as in the first and second embodiments, the spray nozzle 40 and the circulation line 30 can be prevented from being blocked and corroded, and the operation can be continued stably.

  In the first embodiment and the second embodiment, the oxidizer supplier 50 is an oxidant air blower 51 that supplies air as an oxidizer to the liquid reservoir 14, and the air introduction system 60 is the oxidizer. An air blower 51, an air discharge valve 54 provided in the atmospheric discharge line 53 branched from the outlet side of the oxidized air blower 51, and a branch from the outlet side of the air outlet valve 54 were connected to the circulation line 30. An air introduction line 61, a switching valve 62 provided at a branch point of the air introduction line 61, and a purge valve 63 provided in the air introduction line 61 downstream from the switching valve 62 are provided. If comprised in this way, when the circulation pump 20 stops, the surplus air that has been released into the atmosphere can be utilized, which is effective in eliminating wasteful operation.

  In the first and second embodiments, a check valve 64 provided in the air introduction line 61 on the outlet side from the purge valve 63 is provided. With this configuration, the check valve 64 can prevent the absorption liquid from flowing back to the air introduction line 61 during normal operation of the absorption tower 10.

  In the second embodiment, the sensor 70 for detecting the flowing state of the absorbing liquid in the circulation line 30 and the switching valve 62 and the purge valve 63 are controlled based on the flowing state of the absorbing liquid detected by the sensor 70. And a controller 80 for outputting signals 81 and 82. With this configuration, air can be automatically supplied to the spray nozzle 40 and the circulation line 30 by the control signals 81 and 82 from the controller 80.

  In the second embodiment, the sensor 70 may be a pressure gauge 71 provided in the circulation line 30. If comprised in this way, the circulation state of the absorption liquid in the circulation line 30 can be judged by detecting the pressure of the circulation line 30 with the pressure gauge 71. FIG.

  In the second embodiment, the sensor 70 may be a flow meter 72 provided in the circulation line 30. If comprised in this way, the flow state of the absorption liquid in the circulation line 30 can be judged by detecting the flow volume of the circulation line 30 with the flowmeter 72. FIG.

  In the third embodiment, the air introduction system 60 includes an air supply line 65 that can be connected to a washing water supply line 90 connected to the circulation line 30, and an air supply that supplies air to the air supply line 65. And a blower 66. If comprised in this way, when the existing washing water supply line 90 is connected to the circulation line 30, if this washing water supply line 90 is utilized, without newly providing a dedicated nozzle etc. in the circulation line 30, Air can be supplied from the air supply blower 66 to the spray nozzle 40 by a simple operation of simply connecting the air supply line 65 to the cleaning water supply line 90.

  Further, in the first embodiment, the second embodiment, and the third embodiment, the spray nozzle 40 is provided with a reserve in which the absorbing liquid is not ejected during the normal operation of the absorption tower 10. In this case, if air is supplied to the spare spray nozzle 40 during normal operation of the absorption tower 10, blockage and corrosion of the spare spray nozzle 40 can be prevented.

  In addition, as a flue gas desulfurization device equipped with the absorption liquid circulation system blockage / corrosion prevention device in the first embodiment, the second embodiment and the third embodiment, preventing the spray nozzle 40 and the circulation line 30 from being blocked and corroded, Driving can be continued stably.

  In addition, the absorption liquid circulation system blockage / corrosion prevention device and the flue gas desulfurization device of the flue gas desulfurization device of the present invention are not limited to the above-described embodiments, and various types are possible without departing from the gist of the present invention. Of course, changes can be made.

DESCRIPTION OF SYMBOLS 10 Absorption tower 14 Liquid reservoir 20 Circulation pump 30 Circulation line 40 Spray nozzle 50 Oxidant supply device 51 Oxidation air blower 53 Atmospheric discharge line 54 Air discharge valve 60 Air introduction system 61 Air introduction line 62 Switching valve 63 Purge valve 64 Check valve 65 Air supply line 66 Air supply blower 70 Sensor 71 Pressure gauge 72 Flow meter 80 Controller 81 Control signal 82 Control signal 90 Washing water supply line

Claims (9)

An absorption tower, a circulation pump for pumping up the absorption liquid stored in the liquid reservoir of the absorption tower, a circulation line for circulating the absorption liquid pumped up by the circulation pump, and the absorption liquid connected to the circulation line Absorbing liquid circulation system blockage / corrosion prevention device of flue gas desulfurization device provided with spray nozzle ejected inside absorption tower, and oxidant supplier for supplying oxidant to liquid reservoir,
Absorption liquid circulation system blockage / corrosion prevention device of flue gas desulfurization apparatus provided with air introduction system for guiding air to spray nozzle from which said absorption liquid is not jetted. The oxidant feeder is an oxidant air blower that supplies air as an oxidant to the liquid reservoir.
The air introduction system is
The oxidized air blower;
An air discharge valve provided in an air discharge line branched from the outlet side of the oxidized air blower;
An air introduction line branched from the outlet side of the discharge valve and connected to the circulation line;
A switching valve provided at a branch point of the air introduction line;
The apparatus of claim 1, further comprising: a purge valve provided in an air introduction line downstream of the switching valve.   3. The apparatus for blocking / absorbing an absorption liquid circulation system of a flue gas desulfurization apparatus according to claim 2, further comprising a check valve provided in an air introduction line on the outlet side from the purge valve. A sensor for detecting a flow state of the absorbing liquid in the circulation line;
The controller for outputting a control signal to the switching valve and the purge valve based on the flow state of the absorbent detected by the sensor Prevention device.   The said sensor is a pressure gauge provided in the said circulation line, The absorption liquid circulation system blockage | corrosion prevention apparatus of the flue gas desulfurization apparatus of Claim 4 characterized by the above-mentioned.   The said sensor is a flowmeter provided in the said circulation line, The absorption liquid circulation system obstruction | occlusion and corrosion prevention apparatus of the flue gas desulfurization apparatus of Claim 4. The air introduction system is
An air supply line connectable to a wash water supply line connected to the circulation line;
The apparatus for blocking / corrosion of the absorbing liquid circulation system of the flue gas desulfurization apparatus according to claim 1, further comprising an air supply blower for supplying air to the air supply line.   The said spray nozzle is an absorption liquid circulation system blockage | corrosion prevention apparatus of the flue gas desulfurization apparatus as described in any one of Claims 1-7 provided with the reserve from which an absorption liquid is not ejected at the time of the normal operation of the said absorption tower.   A flue gas desulfurization apparatus comprising the absorbent circulation system blockage / corrosion prevention apparatus according to any one of claims 1 to 8.

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