Bottom liquid level control mechanism for ship tail gas desulfurization tower

Abstract

The utility model discloses a bottom liquid level control mechanism for a ship tail gas desulfurization tower, which comprises a high liquid level monitor and an ultrahigh liquid level monitor which are arranged on the side wall of a tower body of the desulfurization tower, and the high liquid level monitor is positioned upwards at the bottom of the desulfurization tower and is within the height of the upper edge of a high-temperature flue gas inlet of the desulfurization tower; the ultrahigh liquid level monitor is located at the position 0.15-0.25 m above the high liquid level monitor. A pressure sensor and a proportional control valve are sequentially arranged on the washing water discharge pipeline, and the pressure sensor is positioned above the proportional control valve; and an inlet of the detection branch pipe is connected with a washing water discharge pipeline between the pressure sensor and the proportional control valve. The device is simple to assemble, has two safeties, can ensure that the liquid level at the bottom of the desulfurizing tower is kept stable, and can ensure that water at the bottom of the desulfurizing tower is sealed in the tower without the phenomenon of tower flooding.

Description

Technical Field

[0001] The utility model belongs to the technical field of ship exhaust gas desulfurization towers, in particular to a bottom liquid level control mechanism for ship exhaust gas desulfurization towers. Background Art

[0002] The liquid level control system at the bottom of a ship's exhaust gas desulfurization tower needs to adapt to various harsh environments. The problems to be solved are: 1. When the desulfurization tower is in operation, a large amount of liquid is sprayed down from the top of the tower. After the liquid is collected, it flows to the drain port at the bottom of the desulfurization tower and is discharged along the external discharge pipe. The water flow has a strong impact force and will carry away some gas. The entrained gas will affect the flow rate of the water in the external discharge pipe, resulting in untimely discharge of the washing water. 2. The washing water quality detector uses a water pump to extract washing water for testing. If the solution in the pipe is not full or there is air, the water pump will not be able to pump out the liquid, or bubbles will enter the pumped liquid, causing cavitation and flow interruption in the small sampling pipeline, thereby damaging the water pump, or causing the monitoring data of the water quality detector to show null values, causing the desulfurization system control program to issue a false alarm that the washing water test indicators fail to meet the standards. Therefore, it is necessary to ensure that there is a full pipe of solution at the inlet of the washing water analyzer. 3. Failure to drain the desulfurization tower's bottom promptly will cause the liquid level to rise continuously, blocking the desulfurization tower's air intake pipe, resulting in poor air intake or increased pressure drop, which can lead to poor engine performance or even stalling. 4. As the liquid level at the bottom of the desulfurization tower continues to rise, the weight inside the tower increases, and the desulfurization tower's support legs may be unable to withstand the increased weight, causing them to deform or break. This can also increase the ship's center of gravity and affect its stability. Therefore, stable control of the liquid level at the bottom of the desulfurization tower is particularly important for the normal operation of the ship's exhaust gas desulfurization system and the vessel itself.

[0003] For example, patent document CN116514207A discloses a defoaming device for wash water in a marine exhaust gas wet open-loop desulfurization system. Installed on the detection branch pipe of the desulfurization tower's wash water outlet, the defoaming device prevents bubbles from entering the water quality detector. However, this document addresses the second problem mentioned above but fails to address the other three. Utility Model Content

[0004] The purpose of the utility model is to provide a bottom liquid level control mechanism for a ship exhaust gas desulfurization tower, which stabilizes the liquid level at the bottom of the desulfurization tower, facilitates the extraction of solution for detection by a washing water analyzer, and reduces the risk of flooding the desulfurization tower.

[0005] The purpose of this utility model is achieved through the following technical solutions:

[0006] The utility model discloses a bottom liquid level control mechanism for a ship exhaust gas desulfurization tower, which is characterized by comprising: a high liquid level monitor and an ultra-high liquid level monitor arranged on the side wall of the tower body of the desulfurization tower, the high liquid level monitor being located upward from the bottom of the desulfurization tower to the height of the upper edge of the high-temperature flue gas inlet of the desulfurization tower; the ultra-high liquid level monitor being located 0.15 to 0.25 meters above the high liquid level monitor; a pressure sensor and a proportional control valve being sequentially provided on the washing water discharge pipe, the pressure sensor being located above the proportional control valve; and an inlet of a detection branch pipe being connected to the washing water discharge pipe between the pressure sensor and the proportional control valve.

[0007] The utility model operates as follows: when the liquid level at the bottom of the desulfurization tower rises to the high liquid level monitor, the high liquid level monitor will alarm, reminding the operator to check the liquid level of the desulfurization tower; when the liquid level at the bottom of the desulfurization tower continues to rise to the ultra-high liquid level monitor, the ultra-high liquid level monitor will alarm, and the external control system will shut down the seawater pump connected to the seawater inlet, stopping the supply of seawater into the desulfurization tower. At the same time, the proportional control valve on the wash water discharge pipe will be fully opened to quickly drain excess wash water from the bottom of the desulfurization tower to prevent flooding. When the pressure sensor detects that the liquid level in the wash water discharge pipe exceeds a specified height, an alarm will be issued, and the control system will stop the seawater pump and fully open the proportional control valve to quickly drain excess wash water from the bottom of the desulfurization tower to prevent flooding. This serves as a second line of defense when the high liquid level monitor and the ultra-high liquid level monitor fail to issue a liquid level alarm.

[0008] The utility model has the following beneficial effects:

[0009] The utility model is simple to assemble and has two insurances, which can ensure that the liquid level at the bottom of the desulfurization tower remains stable, and the tower will not be flooded. It can also ensure that the water seal at the bottom of the desulfurization tower exists, and the gas will not be discharged through the external exhaust pipe at the bottom of the desulfurization tower. At the same time, the washing water analyzer can also smoothly draw water samples. It is safe and reliable and can meet the requirements for liquid level control at the bottom of the ship's exhaust gas desulfurization tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a schematic structural diagram of Example 1 of the present utility model;

[0011] Among them: 1-desulfurization tower, 2-high-temperature flue gas inlet, 3-bottom drain outlet, 4-washing water discharge pipe, 5-detection branch pipe inlet, 6-washing water quality detector, 7-pressure sensor, 8-proportional control valve, 9-high liquid level monitor, 10-ultra-high liquid level monitor, 11-seawater inlet, 12-gas discharge outlet, 13-washing water discharge outlet, 14-detection branch pipe outlet. DETAILED DESCRIPTION

[0012] Those skilled in the art should realize that this embodiment is only used to illustrate the present invention, and is not intended to limit the present invention.

[0013] Example 1

[0014] like Figure 1 A bottom liquid level control mechanism for a ship exhaust gas desulfurization tower is characterized by comprising: a high liquid level monitor 9 and an ultra-high liquid level monitor 10, both located on the sidewall of the desulfurization tower. The high liquid level monitor 9 is located upward from the bottom of the desulfurization tower to the upper edge of the high-temperature flue gas inlet 2 of the desulfurization tower; the ultra-high liquid level monitor 10 is located 0.15 to 0.25 meters above the high liquid level monitor 9; a pressure sensor 7 and a proportional control valve 8 are sequentially provided on a wash water discharge pipe 4, with the pressure sensor 7 located above the proportional control valve 8; and a detection branch pipe inlet 5 is connected to the wash water discharge pipe 4 between the pressure sensor 7 and the proportional control valve 8.

[0015] When the liquid level at the bottom of the desulfurization tower 1 rises to the high liquid level monitor 9, the high liquid level monitor 9 alarms, reminding the operator to check the liquid level of the desulfurization tower; when the liquid level at the bottom of the desulfurization tower 1 continues to rise to the ultra-high liquid level monitor 10, the ultra-high liquid level monitor 10 alarms, and the external control system shuts down the seawater pump connected to the seawater inlet 11, stops supplying seawater into the desulfurization tower 1, and at the same time fully opens the proportional control valve 8 on the washing water discharge pipe 4 to quickly discharge the excess washing water at the bottom of the desulfurization tower 1 to prevent the tower from flooding.

[0016] The pressure sensor 7 and proportional control valve 8 on the wash water discharge pipe 4 form a closed-loop control logic, controlling the liquid level above the proportional control valve 8 to approximately 3 meters. This section of the liquid level indicates full pipe filling, meeting the sampling requirements of the wash water quality detector 6. When the pressure sensor 7 detects that the liquid level in the wash water discharge pipe 4 exceeds a specified height, an alarm is triggered, and the control system stops the seawater pump and fully opens the proportional control valve 8, rapidly draining excess wash water from the bottom of the desulfurization tower 1 to prevent tower flooding. This serves as a second line of defense against failure of the high liquid level monitor 9 and the ultra-high liquid level monitor 10 to issue a liquid level alarm.

[0017] Preferably, the high liquid level monitor 9 and the ultra-high liquid level monitor 10 are both tuning fork liquid level switches.

[0018] Preferably, the vertical distance between the proportional control valve 8 on the washing water discharge pipe 4 and the bottom drain port 3 of the desulfurization tower 1 is about 5 to 10 meters; the proportional control valve 8 can accurately control the opening of the valve, and by adjusting the opening size, the height of the liquid level in the pipe above the valve is controlled.

[0019] Preferably, the vertical distance between the pressure sensor 7 on the washing water discharge pipe and the proportional control valve 8 is 0.2 to 1.0 meters; the pressure sensor 7 monitors the pressure of the water in the washing water discharge pipe 4 and converts it into a liquid level height. When the liquid level height exceeds the set value, the control system adjusts the opening of the proportional control valve 8 to become larger to discharge more washing water. When the liquid level height is lower than the set value, the control system adjusts the opening of the proportional control valve 8 to become smaller to reduce the amount of washing water discharged.

[0020] Preferably, the washing water discharge pipe 4 above the pressure sensor 7 has a straight pipe section of 2 to 3 meters, so that the gas entrained by the liquid can be discharged upward smoothly and will not be carried downward out of the desulfurization tower by the liquid.

[0021] Preferably, the detection branch pipe inlet 5 is located at least 0.5 meters above the proportional control valve 8, where the liquid is full in the pipe, which is convenient for sampling; the detection branch pipe outlet 14 is located at least 0.2 meters below the proportional control valve 8, where there is negative pressure, which is convenient for the discharge of liquid after detection.

[0022] Preferably, the detection branch pipe inlet 5 and the pressure inlet of the pressure sensor 7 should be located in the upper middle part of the straight pipe section of the washing water discharge pipe 4, and must not be located at the bottom of the straight pipe section of the washing water discharge pipe 4, so as to prevent the sediment deposited at the bottom of the pipe from entering the pipeline of the washing water quality detector 6 and the pressure inlet pipeline of the pressure sensor 7, thereby causing blockage.

[0023] Preferably, the proportional control valve 8 is a single-acting pneumatic proportional control butterfly valve with a positioner and a handle, which can display the specific valve opening and has a fault opening function. When the valve fails or the gas source or power supply is lost, the valve can be automatically fully opened to ensure that the washing water can be smoothly discharged out of the tower when the desulfurization system fails.

Claims

1. A bottom liquid level control mechanism for a ship exhaust gas desulfurization tower, characterized in that: include: A high liquid level monitor (9) and an ultra-high liquid level monitor (10) are provided on the side wall of the desulfurization tower, wherein the high liquid level monitor (9) is located upward from the bottom of the desulfurization tower to the upper edge height of the high-temperature flue gas inlet (2) of the desulfurization tower; the ultra-high liquid level monitor (10) is located 0.15 to 0.25 meters above the high liquid level monitor (9); a pressure sensor (7) and a proportional control valve (8) are provided in sequence on the washing water discharge pipe (4), wherein the pressure sensor (7) is located above the proportional control valve (8); and the detection branch pipe inlet (5) is connected to the washing water discharge pipe (4) between the pressure sensor (7) and the proportional control valve (8).

2. The bottom liquid level control mechanism according to claim 1, characterized in that: The high liquid level monitor (9) and the ultra-high liquid level monitor (10) are both tuning fork liquid level switches.

3. The bottom liquid level control mechanism according to claim 1, characterized in that: The vertical distance between the proportional control valve (8) on the wash water discharge pipe (4) and the bottom drain port (3) of the desulfurization tower (1) is 5 to 10 meters.

4. The bottom liquid level control mechanism according to claim 1, characterized in that: The vertical distance between the pressure sensor (7) on the washing water discharge pipe and the proportional control valve (8) is 0.2 to 1.0 meters.

5. The bottom liquid level control mechanism according to claim 1, characterized in that: The washing water discharge pipe (4) above the pressure sensor (7) has a straight pipe section of 2 to 3 meters.

6. The bottom liquid level control mechanism according to claim 1, characterized in that: The detection branch pipe inlet (5) is located at least 0.5 meters above the proportional control valve (8); and the detection branch pipe outlet (14) is located at least 0.2 meters below the proportional control valve (8).

7. The bottom liquid level control mechanism according to claim 1, characterized in that: The detection branch pipe inlet (5) and the pressure inlet of the pressure sensor (7) should be located in the upper middle portion of the straight pipe section of the washing water discharge pipe 4 and should not be located at the bottom of the straight pipe section of the washing water discharge pipe 4.

8. The bottom liquid level control mechanism according to claim 1, characterized in that: The proportional control valve (8) is a single-acting pneumatic proportional control butterfly valve.

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