A wet desulfurization system

Abstract

The present invention provides a wet desulfurization system. The wet desulfurization system of the present invention includes an absorption tower and a controller. A slurry discharge pipe is provided at the outlet end of the absorption tower. A gypsum slurry discharge pump is provided on the slurry discharge pipe. A slurry pipe, a detection pipe and a return tower pipe are provided in parallel at the outlet end of the slurry discharge pipe. A slurry discharge valve is provided on the slurry pipe. A slurry inlet valve and a pH meter are provided in sequence on the detection pipe. A return tower valve is provided on the return tower pipe. The outlet end of the slurry pipe is connected to the gypsum cyclone. The outlet ends of the detection pipe and the return tower pipe are connected to the absorption tower. The controller is electrically connected to each valve to control each valve. The wet desulfurization system of the present invention can reduce the scouring damage to the pH meter when the gypsum is shut down, effectively reduces the failure rate of the pH meter, is conducive to the long-term stable operation of the wet desulfurization system, and has a wide range of use value in the wet desulfurization process.

Description

Technical Field

[0001] The present invention relates to the technical field of desulfurization, in particular to a wet desulfurization system. Background Art

[0002] Wet flue gas desulfurization (FGD) is characterized by its desulfurization system being located at the end of the flue, after the dust collector. The reaction temperature during the desulfurization process is below the dew point, and because it is a gas-liquid reaction, the desulfurization reaction is fast and efficient. The gypsum method, by injecting air into the slurry in the absorber, forcibly oxidizes CaSO₃ to CaSO₄, resulting in gypsum as a desulfurization byproduct. The gypsum method offers distinct advantages, including a wide range of applications, high desulfurization efficiency, high absorbent utilization, high equipment availability, high reliability, and a plentiful and inexpensive desulfurizer source. It is currently the most mature FGD process.

[0003] Absorber slurry pH meters are used to measure the pH of slurry in wet flue gas desulfurization (FGD) systems in thermal power plants. They are typically installed on a branch pipe from the gypsum slurry pump outlet, located at the same location as the slurry pipeline that carries the slurry to the gypsum cyclone. However, in actual operation, this setup has been found to be prone to erosion damage to the pH meter, increasing its failure rate and hindering the long-term stable operation of the wet flue gas desulfurization system.

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

[0005] The object of the present invention is to provide a wet desulfurization system, which can reduce the scouring damage to the pH meter when the gypsum is shut down, effectively reduce the failure rate of the pH meter, and is conducive to the long-term stable operation of the wet desulfurization system.

[0006] The present invention provides a wet desulfurization system, comprising an absorption tower and a controller, wherein a slurry discharge pipe is provided at the outlet end of the absorption tower, a gypsum slurry discharge pump is provided on the slurry discharge pipe, a slurry pipe, a detection pipe and a return-tower pipe are provided in parallel at the outlet end of the slurry discharge pipe, a slurry discharge valve is provided on the slurry pipe, a slurry inlet valve and a pH meter are provided in sequence on the detection pipe, a return-tower valve is provided on the return-tower pipe, the outlet end of the slurry pipe is connected to a gypsum cyclone, the outlet ends of the detection pipe and the return-tower pipe are connected to the absorption tower, and the controller is electrically connected to each valve to control each valve.

[0007] Furthermore, a pH meter flushing pipeline is provided at the inlet end of the pH meter, and a pH meter flushing valve is provided on the pH meter flushing pipeline.

[0008] Furthermore, a return tower flushing pipeline is provided at the outlet end of the return tower valve, and a return tower flushing valve is provided on the return tower flushing pipeline.

[0009] Furthermore, a density meter is provided on the detection pipeline, and the density meter is electrically connected to the controller.

[0010] Furthermore, when the density meter detects that the slurry density is less than the preset value, the controller simultaneously controls the slurry discharge valve to close and the return tower valve to open; when the density meter detects that the slurry density is greater than or equal to the preset value, the controller simultaneously controls the slurry discharge valve to open and the return tower valve to close.

[0011] Furthermore, an alkali adding device for adding limestone to the absorption tower is provided on the absorption tower.

[0012] Furthermore, when the pH meter detects that the pH value of the slurry is less than a preset value, the controller controls the alkali adding device to turn on; when the pH meter detects that the pH value of the slurry is greater than or equal to the preset value, the controller controls the alkali adding device to turn off.

[0013] Furthermore, an inlet valve is provided at the inlet end of the gypsum slurry pump, and an outlet valve is provided at the outlet end of the gypsum slurry pump.

[0014] Furthermore, the diameter of the return tower pipeline is the same as that of the slurry pipeline, and the diameter of the detection pipeline is 1 / 3 of the diameter of the slurry pipeline.

[0015] Furthermore, the slurry discharge valve is an electric valve, and the return tower valve is a pneumatic valve.

[0016] The wet flue gas desulfurization system of the present invention is provided with a slurry pipeline, a detection pipeline and a return tower pipeline in parallel at the outlet end of the slurry discharge pipeline. When the slurry discharge valve on the slurry pipeline is closed, the return tower valve of the return tower pipeline is opened, so that the slurry returns to the absorption tower through the return tower pipeline, avoiding damage to the pH meter caused by excessive slurry pressure and flow rate in the detection pipeline, effectively reducing the failure rate of the pH meter, being beneficial to the long-term stable operation of the wet flue gas desulfurization system, and having wide application value in the wet flue gas desulfurization process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a schematic structural diagram of a wet desulfurization system according to one embodiment of the present invention;

[0019] Figure 2 This is a schematic structural diagram of a wet desulfurization system according to another embodiment of the present invention.

[0020] Description of reference numerals:

[0021] 1: Absorption tower; 2: Slurry discharge pipe; 3: Gypsum slurry discharge pump; 4: Inlet valve; 5: Outlet valve; 6: Slurry pipe; 7: Detection pipe; 8: Return tower pipe; 9: Slurry discharge valve; 10: Slurry inlet valve; 11: pH meter; 12: Return tower valve; 13: pH meter flushing pipe; 14: pH meter flushing valve; 15: Return tower flushing pipe; 16: Return tower flushing valve; 17: Density meter. DETAILED DESCRIPTION

[0022] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0023] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular also includes the plural. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0024] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] Example 1

[0026] like Figure 1 As shown, the wet flue gas desulfurization system of this embodiment includes an absorption tower 1 and a controller (not shown in the figure), a slurry discharge pipe 2 is provided at the outlet end of the absorption tower 1, a gypsum slurry discharge pump 3 is provided on the slurry discharge pipe 2, a slurry pipe 6, a detection pipe 7 and a return tower pipe 8 are provided in parallel at the outlet end of the slurry discharge pipe 2, a slurry discharge valve 9 is provided on the slurry pipe 6, a slurry inlet valve 10 and a pH meter 11 are provided in sequence on the detection pipe 7, and a return tower valve 12 is provided on the return tower pipe 8, the outlet end of the slurry pipe 6 is connected to the gypsum cyclone, and the outlet ends of the detection pipe 7 and the return tower pipe 8 are connected to the absorption tower 1, and the controller is electrically connected to each valve to control each valve.

[0027] The wet flue gas desulfurization system of this embodiment is provided with a slurry discharge pipe 2 at the outlet end of the absorption tower 1. The slurry discharge pipe 2 is used to transport the slurry in the absorption tower 1 to the slurry pipe 6, the detection pipe 7 and the return pipe 8 at the outlet end. A gypsum slurry discharge pump 3 is provided on the slurry discharge pipe 2, an inlet valve 4 is provided at the inlet end of the gypsum slurry discharge pump 3, and an outlet valve 5 is provided at the outlet end of the gypsum slurry discharge pump 3.

[0028] A slurry pipeline 6, a detection pipeline 7 and a return tower pipeline 8 are arranged in parallel at the outlet end of the slurry discharge pipeline 2. The slurry pipeline 6 is mainly used to send the slurry to the gypsum cyclone for subsequent treatment. A slurry discharge valve 9 is provided on the slurry pipeline 6, and the outlet end of the slurry pipeline 6 is connected to the gypsum cyclone; the detection pipeline 7 is mainly used to detect the slurry. A slurry inlet valve 10 and a pH meter 11 for detecting the pH value of the slurry are sequentially provided on the detection pipeline 7, and the outlet end of the detection pipeline 7 is connected to the absorption tower 1; the return tower pipeline 8 is mainly used to return the slurry to the absorption tower 1 when the slurry discharge valve 9 is closed, so as to avoid damage to the pH meter 11 due to excessive slurry pressure and flow rate in the detection pipeline 7. A return tower valve 12 is provided on the return tower pipeline 8, and the outlet end of the return tower pipeline 8 is connected to the absorption tower 1.

[0029] Specifically, the return tower pipe 8 and the slurry pipe 6 have the same diameter, for example, DN150. The diameter of the detection pipe 7 is 1 / 3 of the diameter of the slurry pipe 6, for example, DN50. Furthermore, there are no strict restrictions on the type of valves, and they can be reasonably set according to actual needs. For example, the slurry discharge valve 9 can be an electric valve, and the return tower valve 12 can be a pneumatic valve.

[0030] Furthermore, a pH meter flushing pipe 13 is provided at the inlet end of the pH meter 11, and a pH meter flushing valve 14 is provided on the pH meter flushing pipe 13 to flush the pH meter 11. In addition, a return tower flushing pipe 15 is provided at the outlet end of the return tower valve 12, and a return tower flushing valve 16 is provided on the return tower flushing pipe 15 to flush the return tower pipe 8.

[0031] The controller is electrically connected to the gypsum slurry pump 3 and each valve to control the gypsum slurry pump 3 and each valve; specifically, when the gypsum discharge is stopped and the slurry discharge valve 9 is closed, the return tower valve 12 is interlocked to open, thereby returning the excess slurry to the absorption tower 1, thereby avoiding damage to the pH meter 11 caused by excessive slurry pressure and flow rate in the measuring pipeline.

[0032] It is understood that the absorption tower 1 is provided with an alkali adding device (not shown) for adding limestone to the absorption tower 1. When the pH meter 11 detects that the pH value of the slurry is less than a preset value, the controller controls the alkali adding device to turn on; when the pH meter 11 detects that the pH value of the slurry is greater than or equal to the preset value, the controller controls the alkali adding device to turn off, thereby ensuring that the pH value of the slurry in the absorption tower 1 is within an appropriate pH range, for example, pH 5.2-5.8.

[0033] The wet flue gas desulfurization system of this embodiment is provided with a slurry pipeline 6, a detection pipeline 7 and a return tower pipeline 8 in parallel at the outlet end of the slurry discharge pipeline 2. When the slurry discharge valve 9 on the slurry pipeline 6 is closed, the return tower valve 12 of the return tower pipeline 8 is opened, so that the slurry returns to the absorption tower 1 through the return tower pipeline 8, avoiding damage to the pH meter 11 caused by excessive slurry pressure and flow rate in the detection pipeline 7, effectively reducing the failure rate of the pH meter 11, which is beneficial to the long-term stable operation of the wet flue gas desulfurization system and has wide application value in the wet flue gas desulfurization process.

[0034] Example 2

[0035] Combine Figure 1 、 Figure 2 As shown, the wet desulfurization system of this embodiment is based on the wet desulfurization system of Example 1, and a density meter 17 is further provided on the detection pipe 7. The density meter 17 is electrically connected to the controller.

[0036] Specifically, the density meter 17 and the pH meter 11 can be arranged in parallel on the detection pipe 7; the density meter 17 is used to detect the density of the slurry to ensure that the density of the slurry in the absorption tower 1 is within a suitable range, for example, 1110-1130 kg / m 3 .

[0037] The density meter 17 is electrically connected to the controller. When the density meter 17 detects that the slurry density is less than the preset value, the controller simultaneously controls the slurry discharge valve 9 to close and the return tower valve 12 to open; when the density meter 17 detects that the slurry density is greater than or equal to the preset value, the controller simultaneously controls the slurry discharge valve 9 to open and the return tower valve 12 to close.

[0038] The wet flue gas desulfurization system of this embodiment has a simple structure, is easy to implement and requires little investment. By setting a return tower pipe 8 and a return tower valve 12, the return tower valve 12 is immediately interlocked and opened when the slurry discharge valve 9 is closed, so that the slurry returns to the absorption tower 1 through the return tower pipe 8, avoiding damage to the pH meter 11 caused by excessive slurry pressure and flow rate in the detection pipe 7, and ensuring the safe operation of the system. This setting method is simple to operate and flexible to control, and can effectively reduce the scouring and damage to the pH meter 11 when the gypsum is shut down, effectively reducing the failure rate of the pH meter 11, and has high social and economic benefits. In addition, the above setting method is applicable to most wet flue gas desulfurization systems and has a high value of promotion and use.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wet desulfurization system, characterized in that: The invention comprises an absorption tower and a controller, wherein a slurry discharge pipe is provided at the outlet end of the absorption tower, a gypsum slurry discharge pump is provided on the slurry discharge pipe, a slurry pipe, a detection pipe and a return pipe are provided in parallel at the outlet end of the slurry discharge pipe, a slurry discharge valve is provided on the slurry pipe, a slurry inlet valve and a pH meter are provided on the detection pipe in sequence, a return pipe is provided on the return pipe, the outlet end of the slurry pipe is connected to the gypsum cyclone, the outlet end of the detection pipe and the return pipe are connected to the absorption tower, the controller is electrically connected to each valve to control each valve, the return pipe and the slurry pipe have the same diameter, the detection pipe and the return pipe are connected to each other, and the return pipe is connected to each other. The diameter of the pipeline is 1 / 3 of the diameter of the slurry pipeline. When the slurry discharge valve on the slurry pipeline is closed, the return valve of the return tower pipeline is opened to allow the slurry to return to the absorption tower through the return tower pipeline. A density meter is also provided on the detection pipeline. The density meter is electrically connected to the controller. When the density meter detects that the slurry density is less than the preset value, the controller simultaneously controls the slurry discharge valve to close and the return tower valve to open; when the density meter detects that the slurry density is greater than or equal to the preset value, the controller simultaneously controls the slurry discharge valve to open and the return tower valve to close. The preset value of the slurry density is 1110-1130 kg / m 3 .

2. The wet desulfurization system according to claim 1, characterized in that: A pH meter flushing pipeline is provided at the inlet end of the pH meter, and a pH meter flushing valve is provided on the pH meter flushing pipeline.

3. The wet desulfurization system according to claim 1, characterized in that: A return tower flushing pipeline is provided at the outlet end of the return tower valve, and a return tower flushing valve is provided on the return tower flushing pipeline.

4. The wet desulfurization system according to claim 1, characterized in that: The absorption tower is provided with an alkali adding device for adding limestone to the absorption tower.

5. The wet desulfurization system according to claim 4, characterized in that: When the pH meter detects that the pH value of the slurry is less than the preset value, the controller controls the alkali adding device to turn on; when the pH meter detects that the pH value of the slurry is greater than or equal to the preset value, the controller controls the alkali adding device to turn off.

6. The wet desulfurization system according to claim 1, characterized in that: An inlet valve is provided at the inlet end of the gypsum slurry discharge pump, and an outlet valve is provided at the outlet end of the gypsum slurry discharge pump.

7. The wet desulfurization system according to claim 1, characterized in that: The slurry discharge valve is an electric valve and the return tower valve is a pneumatic valve.

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