PH and density detection system for wet desulphurization process

Abstract

The utility model discloses a PH and density detection system for a wet desulphurization process. The PH and density detection system comprises a plurality of sampling branch pipes, a sampling header pipe and a detection tank, the number of the sampling branch pipes corresponds to the number of circulating pumps on the desulfurizing tower, one end of each sampling branch pipe is connected with an outlet of the circulating pump, the other end of each sampling branch pipe is connected with a sampling header pipe, the sampling header pipe is connected with a slurry inlet in the bottom of a detection tank, and the detection tank is provided with a PH meter interface, a differential pressure densimeter interface and an overflow port. The overflow port is connected with the desulfurization tower through a pipeline; according to the utility model, slurry in all directions in the tower can be comprehensively collected in real time in a manner of sampling at the outlet of the circulating pump, so that the accuracy of PH and density detection data is improved; through a positive pressure sampling mode, pipeline blockage caused by a static pressure self-flowing mode can be avoided; through the electric regulating valves at the head ends of the branch pipes, the flow of each branch sampling pipeline can be balanced, the flow speed of sampling slurry is controlled, the flow stability is ensured, and the abrasion of an instrument probe is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of flue gas treatment technology, specifically relating to a pH and density detection system for a wet desulfurization process. Background Technology

[0002] The statements herein provide only background information related to this invention and do not necessarily constitute prior art.

[0003] Currently, wet desulfurization technology stands out due to its unique advantages. Through countercurrent gas-liquid contact, the reaction is fast and complete, and the utilization rate of desulfurization additives is high. For example, when lime is used as a desulfurizing agent, a desulfurization efficiency of over 90% can be achieved when Ca / S = 1. It is suitable for flue gas produced by the combustion of high-sulfur coal. After years of development, its production and operation are safe and reliable, and it has accumulated rich experience in design, manufacturing, installation, operation, and maintenance. It is suitable for power plants and industrial boilers of various sizes, especially large power plants. The by-product gypsum can be used in building materials, cement, and other industries, possessing certain economic value.

[0004] pH and density, as key process parameters, affect the reaction efficiency of gas-liquid two-phase contact within the tower, thus impacting the final waste gas removal effect. Density, as a key indicator of the solid content of the slurry within the tower, determines the selection of the gypsum discharge dewatering time. However, in traditional wet desulfurization systems, both pH and density are located around the perimeter of the tower body. pH is often achieved through gravity flow via external pipes connected to perforated flanges in the wall panels, while density is detected online using static pressure within the tower. This design introduces several problems: First, pH, achieved through full-flow static pressure slurry, will self-block as the liquid density within the tower gradually increases, and the solidification after discharge leads to a significant amount of manual cleaning, also affecting the water balance within the tower. Second, placing the differential pressure density interface around the tower can cause sampling port blockage due to rising liquid density. Simultaneously, the oxidation wind and severe disturbance of the slurry within the tower can cause a large amount of air to accumulate at the pressure gauge diaphragm, isolating the diaphragm from the slurry and hindering normal detection. Third, all operations are manual, making it difficult to detect abnormal conditions promptly, and frequent cleaning operations result in a continuous and substantial workload. Utility Model Content

[0005] The purpose of this invention is to provide a pH and density detection system for wet desulfurization processes. By using positive pressure sampling, it can avoid pipeline blockage caused by static pressure gravity flow. At the same time, in conjunction with a DCS control system, it can realize the automated control of the entire detection system.

[0006] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0007] In a first aspect, embodiments of this utility model provide a pH and density detection system for a wet desulfurization process, comprising multiple sampling branch pipes, a sampling main pipe, and a detection tank; the number of sampling branch pipes corresponds to the number of circulating pumps on the desulfurization tower, one end of each sampling branch pipe is connected to the outlet of the circulating pump, and the other end is connected to the sampling main pipe, the sampling main pipe is connected to the slurry inlet at the bottom of the detection tank, the detection tank is provided with a pH meter interface, a differential pressure density meter interface, and an overflow port, the overflow port being connected to the desulfurization tower via a pipe.

[0008] As a further technical solution, each sampling branch is equipped with an electric regulating valve.

[0009] As a further technical solution, the head end of the sampling manifold is connected to the flushing pipeline via a flushing electric valve, and the tail end of the sampling manifold is connected to the slurry inlet at the bottom of the detection tank.

[0010] As a further technical solution, the pH meter interface is located on the top of the testing tank, and there are two pH meter interfaces, with a pH meter installed in each interface.

[0011] As a further technical solution, the height of the pH meter's detection probe extending into the detection tank is lower than the height of the overflow port.

[0012] As a further technical solution, the differential pressure density meter interface is located on the side of the detection tank, including an upper interface and a lower interface of the differential pressure density meter connected to the differential pressure density meter.

[0013] As a further technical solution, the upper and lower interfaces of the differential pressure density meter are respectively connected to flushing water pipes, and valves are installed on the flushing water pipes.

[0014] As a further technical solution, the bottom of the testing tank is also provided with an emptying port and a flushing port. The emptying port is connected to a drainage ditch through a pipe for discharge, and the flushing port is connected to a flushing water pipe, which is equipped with a valve.

[0015] As a further technical solution, the testing tank is placed at the zero-meter platform on site. During operation, the testing tank is always full of liquid, and the liquid is always in a flowing state.

[0016] As a further technical solution, a DCS automatic control system is also included, which controls the valves on the sampling branch pipe, the sampling main pipe, and the testing tank.

[0017] The beneficial effects of the above-described embodiments of this utility model are as follows:

[0018] This invention uses a circulating pump outlet sampling method to collect slurry samples from all locations within the tower in real time, thereby improving the accuracy of pH and density detection data. The positive pressure sampling method avoids pipe blockage caused by static pressure gravity flow. The electric regulating valve at the branch pipe head can balance the flow rate of each branch sampling pipeline, control the flow rate of the sampled slurry, ensure stable flow, and reduce wear on the instrument probe.

[0019] This invention combines environmental compliance and operational safety through a fully closed-loop slurry reflux and intelligent venting design. Traditional testing systems require external slurry discharge for cleaning, which can easily cause environmental pollution, and manual venting poses a risk of slurry splashing. In this invention, the overflow port of the testing tank is directly connected to the desulfurization tower, and all slurry is returned after testing, maintaining the liquid level balance within the tower and preventing external pollution. The bottom venting interface and flushing pipe design allow for the control of valves to guide residual slurry into a ditch or recycling system during maintenance, avoiding the difficulties of post-solidification treatment.

[0020] This invention utilizes a DCS control interlock system to enable the detection device to automatically open the corresponding regulating valve based on the pump's operating status and collect the corresponding pump outlet slurry value. By monitoring the values ​​through the DCS control system, it can take measures such as flushing and alarms to promptly and automatically handle any abnormal situations that may occur, maintaining the stable operation of the system. The external detection tank avoids pipe blockage caused by solid slurry and density deviations caused by oxidation wind. Attached Figure Description

[0021] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0022] Figure 1 This is a schematic diagram of the pipeline layout for the pH and density detection system in the wet desulfurization process of this utility model.

[0023] Figure 2 This is a schematic diagram of the structure of the testing tank of this utility model.

[0024] The diagram is for illustrative purposes only.

[0025] The components include: 1. Sampling branch pipe; 2. Electric regulating valve; 3. Sampling main pipe; 4. Detection tank; 401. Upper interface of differential pressure density meter; 402. Lower interface of differential pressure density meter; 403. Slurry inlet; 404. Overflow port; 5. Flushing electric valve; 6. pH meter. Detailed Implementation

[0026] It should be noted that the following detailed description is exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0027] Example 1

[0028] In a typical embodiment of this utility model, such as Figure 1 and Figure 2 As shown, a pH and density detection system for a wet desulfurization process is provided, including multiple sampling branch pipes 1, a sampling main pipe 3, and a detection tank 4. The number of sampling branch pipes 1 corresponds to the number of circulating pumps on the desulfurization tower. One end of each sampling branch pipe 1 is connected to the outlet of the circulating pump, and the other end is connected to the sampling main pipe 3. The sampling main pipe 3 is connected to the slurry inlet 403 at the bottom of the detection tank 4. The detection tank 4 is equipped with a pH meter interface, a differential pressure density meter interface, and an overflow port 404. The overflow port 404 is connected to the desulfurization tower through a pipeline.

[0029] The aforementioned system achieves positive pressure sampling by connecting the sampling branch pipe to the outlet of the circulating pump. The high pressure of the slurry at the circulating pump outlet drives the slurry into the sampling branch pipe, completely avoiding pipe blockage caused by poor slurry flowability in static gravity flow methods. Simultaneously, the external detection tank forms a closed-loop reflux through the overflow port, ensuring continuous slurry flow and renewal, avoiding detection errors caused by localized slurry stagnation or uneven distribution within the tower. Furthermore, the design of returning all slurry to the desulfurization tower maintains the liquid level balance within the tower, eliminating the need for external discharge and significantly reducing manual cleaning workload.

[0030] In this embodiment, each sampling branch pipe 1 is equipped with an electric regulating valve 2, specifically, as shown in the example below. Figure 1 As shown, sampling branch pipe 1 has four sections, each equipped with an electric regulating valve. The DCS control system dynamically adjusts the opening of each valve to achieve flow balance across multiple branches. The opening value can be set from 0-100%, taking into account factors such as slurry flowability, flow balance across multiple sampling branch pipes, and instrument probe wear. Generally, a smaller opening (e.g., 10%) is initially selected for testing, set via the DCS control system. The DCS program incorporates interlocking logic between the regulating valve group and pump operation signals. This means the opening of the valve group is linked to the operation of the corresponding pump. Only pumps in operation will automatically open the sampling regulating valve group on their outlet pipe. Simultaneously, the pump shutdown signal will also trigger the regulating valve to close. This ensures that slurry does not flow back into pumps that are stopped, reduces human error, and decreases workload.

[0031] In this embodiment, the head end of the sampling manifold 3 is connected to the flushing pipeline via a flushing electric valve 5, and the tail end of the sampling manifold 3 is connected to the slurry inlet 403 at the bottom of the detection tank 4. Considering the high solids content, poor fluidity, and tendency to settle in the slurry, this system is designed to ensure continuous slurry fluidity and handle potential abnormal situations. Under normal circumstances, the flushing electric valve is closed. If the DCS remote data transmission experiences a prolonged pause (normal operating values ​​will fluctuate slightly), the system determines that a blockage has occurred, issues a command to open the flushing valve assembly to flush and clear the pipeline, and provides an alarm for operators to check. Simultaneously, if the system shuts down, the valve will also briefly open to clean the pipeline.

[0032] With its automatic flushing design, the DCS system automatically activates the flushing electric valve when the system shuts down or detects abnormal data (such as pH / density values ​​remaining unchanged for 5 minutes). This uses high-pressure flushing water to powerfully flush the sampling main and branch pipes, quickly removing deposits and restoring pipeline flow. This design not only reduces manual intervention but also allows maintenance to be performed without shutting down the system, significantly improving its continuous operation capability. Furthermore, the flushing logic is linked to the detection data, enabling intelligent operation and maintenance with "abnormalities addressed immediately," avoiding data delays or invalidation due to blockages and ensuring the reliability of process control.

[0033] In this embodiment, the pH meter interface is located at the top of the testing tank 4, and there are two pH meter interfaces, each equipped with a pH meter 6. Furthermore, the height of the pH meter probe extending into the testing tank 4 is lower than the height of the overflow port. Traditional single pH meter testing is prone to data distortion due to probe failure or uneven pH distribution in the slurry. Using dual pH meters allows for real-time verification of measurement accuracy by comparing the data from the two probes. Simultaneously, the dual probes, positioned at different locations on the tank top, cover the pH values ​​of different areas of the slurry within the tank, eliminating detection deviations caused by slurry stratification or dead zones, ensuring that the data represents the overall operating conditions. By limiting the probe insertion height to below the overflow port, the probe is always immersed in the flowing slurry, avoiding measurement failures caused by air bubble adhesion or liquid level drops. At the same time, the overflow port design creates a stable liquid surface in the tank, with a moderate slurry flow velocity at the probe location, reducing the mechanical impact of turbulence on the probe and avoiding sedimentation interference in static areas, significantly improving the stability and accuracy of pH value detection.

[0034] In this embodiment, the differential pressure density meter interface is located on the side of the testing tank, including an upper interface 401 and a lower interface 402 connected to the differential pressure density meter. By arranging the differential pressure density meter interface on the side of the testing tank, the slurry density is directly calculated using the formula P = ρgh through the upper and lower interfaces with a fixed height difference (e.g., 1 meter). The external testing tank avoids the effects of slurry settling, poor slurry agitation in certain areas of the tower, uneven distribution, or oxidation wind on the testing data, resulting in real-time and accurate data.

[0035] Furthermore, flushing water pipes are connected to the upper interface 401 and lower interface 402 of the differential pressure density meter, respectively. Valves are installed on these flushing water pipes. Since the differential pressure density meter interfaces are in long-term contact with high-solids slurry, diaphragm blockage or damage can easily occur due to gypsum crystallization or particle deposition. By configuring independent flushing water pipes for the upper and lower interfaces, the valves can be opened during intermittent testing or system maintenance to perform high-pressure flushing of the interfaces and diaphragms, removing deposits and restoring testing accuracy. This design is particularly suitable for long-term desulfurization systems, significantly extending the service life of the differential pressure density meter and reducing replacement frequency. Simultaneously, the flushing operation can be remotely controlled via the DCS system, eliminating the need for manual instrument disassembly and reducing maintenance difficulty and costs.

[0036] In this embodiment, the bottom of the testing tank is also equipped with an emptying port and a flushing port. The emptying port is connected to a drainage ditch via a pipe, and the flushing port is connected to a flushing water pipe equipped with a valve. This design is used during long-term system shutdowns or maintenance. The bottom emptying port allows for rapid drainage of the slurry from the tank into the drainage ditch or recovery system, preventing the slurry from solidifying and becoming difficult to handle. The flushing port allows for thorough cleaning of the tank after emptying, preventing scaling. This design simplifies maintenance procedures, reduces downtime, and meets environmental protection requirements. Furthermore, the independent control of the emptying and flushing valves allows for segmented operation, further enhancing flexibility.

[0037] In this embodiment, the testing tank can be made of FRP (fiberglass reinforced plastic). The tank is positioned at a zero-meter platform on-site. During operation, the tank remains fully filled with liquid, and the liquid is constantly flowing. If the tank is placed at a high position, the slurry requires additional pumping, increasing energy consumption; if placed at a low position, insufficient static pressure may cause flow stagnation. By placing the tank at the zero-meter platform, the positive pressure at the outlet of the circulating pump naturally drives the slurry flow, eliminating the need for additional power and achieving energy efficiency. The full-fill design ensures there is no gas-liquid mixing interface within the tank, preventing air bubbles from interfering with pH and density measurements. Continuous, slow overflow replenishes the slurry, preventing the settling of solid particles and ensuring the representativeness and timeliness of the test data.

[0038] This embodiment also includes a DCS (Distributed Control System) automatic control system, which controls the valves on the sampling branch pipes, the sampling main pipe, and the testing tank. The DCS system achieves fully automatic control: it automatically opens and closes the sampling valves based on the circulating pump status, dynamically adjusts the branch flow rate, monitors pH / density data in real time, and triggers flushing or alarms. For example, when the flow rate of a certain branch is abnormal, the DCS can adjust the opening of the corresponding valve individually to avoid a system shutdown. Furthermore, data history recording and trend analysis functions provide a basis for process optimization, helping to maximize desulfurization efficiency. This design minimizes manual intervention, improves the system's intelligence level, and reduces operation and maintenance costs.

[0039] In this embodiment, the pH meter, differential pressure density meter, and DCS automatic control system all adopt existing structures.

[0040] The working principle of the pH and density detection system for the wet desulfurization process provided in this embodiment is as follows:

[0041] The sampling branch pipes are connected to the outlets of each circulating pump. Each branch sampling pipe is connected to the main pipe after passing through a separate electric regulating valve. The head end of the main pipe is equipped with an electric flushing water valve, and the tail end of the main pipe is connected to the newly added detection tank. The top of the detection tank is equipped with a pH meter interface, the side is equipped with a differential pressure density interface, and the bottom is equipped with an venting and flushing interface. After overflow, the slurry returns to the tower through the outlet pipe.

[0042] A branch pipe interface flange is reserved on the side of the circulating pump outlet pipe. The sampling of the pipeline utilizes the positive pressure of the slurry at the outlet of the circulating pump to reduce the risk of gravity flow blockage. An electric regulating valve is installed at the interface between each sampling branch pipe and the outlet pipe to balance the sampling flow of each sampling pipeline. At the same time, in the DCS program design, the valve actuator is interlocked with the start and stop of the corresponding circulating pump. The control system can automatically open the corresponding valve according to the pump operation command. The corresponding sampling regulating valve of the pump not in operation remains closed. The valve opening can be manually adjusted to adjust the flow rate as needed.

[0043] The sampling manifold is equipped with a process water flushing electric valve. After the system is shut down, the DCS automatic control system will issue a command to perform a flushing operation for a certain period of time. At the same time, if the pH or density value remains unchanged for a certain period of time (e.g., 5 minutes) while the system is running, the control system will determine that there is an abnormality and will automatically start flushing for a period of time. If the normal fluctuation is restored, the valve will be closed; otherwise, an alarm will be set up to notify the operator to check.

[0044] The sampling main pipe is connected to a newly added online monitoring tank. The slurry flows from bottom to top, overflowing when the tank is full. A differential pressure gauge installed on the tank wall measures the pressure difference of the slurry at a predetermined height, which is then converted by the DCS system to obtain the density. A pH meter probe on the tank top also measures the corresponding data upon contact with the slurry, and this data is simultaneously uploaded to the DCS system for operators to view. The tank's evacuation and manual flushing functions can be manually operated when the equipment is shut down. The slurry flow rate is limited by the opening of the electric regulating valves in each sampling branch pipe, but the presence of positive pressure at the pump outlet greatly reduces the possibility of system blockage.

[0045] By using a pH and density detection system for wet desulfurization processes, some new and renovation projects have achieved remarkable results. This system ensures the stability and efficiency of the desulfurization system, improves the accuracy and real-time performance of instrument data, reduces manual workload, and lowers the investment costs associated with other modification schemes. It is an extremely economical process measure.

[0046] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A pH and density detection system for a wet desulfurization process, characterized in that, It includes multiple sampling branch pipes, a sampling main pipe, and a testing tank; the number of sampling branch pipes corresponds to the number of circulating pumps on the desulfurization tower. One end of each sampling branch pipe is connected to the outlet of the circulating pump, and the other end is connected to the sampling main pipe. The sampling main pipe is connected to the slurry inlet at the bottom of the testing tank. The testing tank is equipped with a pH meter interface, a differential pressure density meter interface, and an overflow port. The overflow port is connected to the desulfurization tower through a pipe.

2. The pH and density detection system for wet desulfurization process as described in claim 1, characterized in that, Each sampling branch is equipped with an electric regulating valve.

3. The pH and density detection system for wet desulfurization process as described in claim 1, characterized in that, The head end of the sampling manifold is connected to the flushing pipeline via a flushing electric valve, and the tail end of the sampling manifold is connected to the slurry inlet at the bottom of the detection tank.

4. The pH and density detection system for wet desulfurization process as described in claim 1, characterized in that, The pH meter interface is located on the top of the testing tank, and there are two pH meter interfaces, each of which is equipped with a pH meter.

5. The pH and density detection system for wet desulfurization process as described in claim 4, characterized in that, The height of the pH meter's probe inside the testing tank is lower than the height of the overflow port.

6. The pH and density detection system for wet desulfurization process as described in claim 1, characterized in that, The differential pressure density meter interface is located on the side of the detection tank and includes an upper interface and a lower interface of the differential pressure density meter connected to the differential pressure density meter.

7. The pH and density detection system for wet desulfurization process as described in claim 6, characterized in that, The upper and lower interfaces of the differential pressure density meter are respectively connected to flushing water pipes, and valves are installed on the flushing water pipes.

8. The pH and density detection system for wet desulfurization process as described in claim 1, characterized in that, The bottom of the testing tank is also equipped with an emptying port and a flushing port. The emptying port is connected to a drainage ditch via a pipe, and the flushing port is connected to a flushing water pipe, which is equipped with a valve.

9. The pH and density detection system for wet desulfurization process as described in claim 1, characterized in that, The testing tank is located at the zero-meter platform on site. During operation, the testing tank is always full of liquid, and the liquid is always in a flowing state.

10. The pH and density detection system for wet desulfurization process as described in claim 1, characterized in that, It also includes a DCS automatic control system, which controls the valves on the sampling branch pipe, the sampling main pipe, and the testing tank.

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