High test bleaching powder flue gas self-adjusting washing system

Abstract

The utility model relates to a bleaching powder concentrate flue gas self-adjusting washing system which comprises a flue gas washing tower, the flue gas washing tower is vertically arranged, the top of the flue gas washing tower is provided with a tail gas discharge port, the bottom of the flue gas washing tower is provided with a washing water discharge port, and the inside of the flue gas washing tower comprises an alkali washing section positioned at the upper part and a water washing section positioned at the lower part; an online analyzer is arranged at the tail gas discharge port; a washing liquid inlet and an overflow port are formed in the side wall of the alkali washing section; the washing liquid inlet is communicated with the liquid outlet of the washing tower circulating tank through a washing liquid pipeline; a flow meter and a flow regulating valve are arranged on the washing liquid pipeline; the overflow port is communicated with a reflux port of the washing tower circulating tank through an overflow pipeline; a process water inlet and a flue gas inlet are formed in the side wall of the washing section; the process water inlet is communicated with the process water output end through a pipeline; and the flue gas inlet is communicated with the bleaching powder flue gas output end through a pipeline. Therefore, the tail gas can be detected in real time, the washing liquid flow is adjusted in time, and it is ensured that tail gas emission meets the requirement.

Description

Technical Field

[0001] This utility model relates to a chemical apparatus, and more particularly to a bleaching powder flue gas scrubbing system, specifically a bleaching powder flue gas self-regulating scrubbing system. Background Technology

[0002] The bleaching powder unit is equipped with a flue gas scrubbing tower to scrub the mixture of dry tail gas and wet tail gas in the bleaching powder unit. The process flow is as follows: the flue gas enters the flue gas scrubbing tower from the bottom of the tower. The flue gas scrubbing tower is divided into two sections. The lower section is the water scrubbing section. After the flue gas passes through the cyclone plate, it comes into countercurrent contact with the scrubbing liquid and is washed away to remove solid impurities before entering the upper section. The upper section is the alkaline scrubbing section. The dust removal flue gas and the alkaline solution come into full contact in the packing of the upper section and are washed away to remove small amounts of chlorine and hydrogen chloride before being discharged from the top of the tower.

[0003] According to relevant regulations, the HCl content in the treated waste gas should be lower than 10 mg / m³. 3 The Cl2 content should be less than 5 mg / m³. 3 Dust content should be less than 30 mg / m³ 3 Therefore, it is necessary to detect the HCl and Cl2 content in the exhaust gas in order to adjust the flow rate of the alkaline solution. However, currently, exhaust gas is mainly detected by manual sampling, which makes real-time detection impossible, causing lag and uncertainty in the entire process control and adversely affecting production.

[0004] Therefore, improvements are urgently needed to better meet production demands. Utility Model Content

[0005] The purpose of this invention is to address the problems existing in the current bleaching powder inspection process by providing a self-regulating washing system for bleaching powder flue gas. This system can achieve real-time detection of exhaust gas and adjust the flow rate of washing water containing alkaline solution in a timely manner based on the detection results, ensuring that exhaust gas emissions meet the requirements and creating favorable conditions for smooth production.

[0006] The technical solution of this utility model is:

[0007] A self-regulating scrubbing system for bleaching powder flue gas includes a flue gas scrubbing tower.

[0008] The flue gas scrubbing tower is vertically installed, with a tail gas emission port at the top and a scrubbing water discharge port at the bottom. It includes an alkaline scrubbing section at the top and a water scrubbing section at the bottom. An online analyzer is installed at the tail gas emission port.

[0009] The side wall of the alkaline washing section is provided with a washing liquid inlet and an overflow outlet; the washing liquid inlet is connected to the outlet of the washing tower circulation tank through a washing liquid pipeline; the washing liquid pipeline is provided with a flow meter and a flow regulating valve; the overflow outlet is connected to the return outlet of the washing tower circulation tank through an overflow pipeline.

[0010] The side wall of the washing section is provided with a process water inlet and a flue gas inlet; the process water inlet is connected to the process water output end through a pipeline; the flue gas inlet is connected to the bleaching powder flue gas output end through a pipeline.

[0011] The online analyzer, flow meter, and flow regulating valve form a cascade control system through a flow regulating controller. The setpoint of the flow regulating controller can be adjusted by real-time monitoring of the online analyzer, thereby adjusting the flow regulating valve to change the input amount of washing water.

[0012] Furthermore, the washing liquid inlet is located at the top of the alkaline washing section; the overflow outlet is located at the bottom of the alkaline washing section.

[0013] Furthermore, a flue gas scrubbing pump is installed on the washing liquid pipeline.

[0014] Furthermore, the washing tower circulation tank is equipped with an alkali inlet and a process water inlet; the alkali inlet is connected to the alkali outlet through a pipeline; the process water inlet is connected to the process water outlet through a pipeline.

[0015] Furthermore, a pressure balancing port is provided on the side wall of the gas phase section of the flue gas scrubbing tower; the pressure balancing port is connected to the top of the scrubbing tower circulation tank through a balancing pipeline.

[0016] Furthermore, a circulation port is provided on the side wall of the washing section; the circulation port is connected to the washing water outlet through a circulation pipeline; a dust washing pump is provided on the circulation pipeline.

[0017] Furthermore, the circulation port is located above the process water inlet.

[0018] Furthermore, the washing liquid pipeline is equipped with a first cooler, which can cool the washing liquid from the washing tower circulation tank before it is fed into the flue gas scrubbing tower.

[0019] Furthermore, a second cooler is provided on the circulation pipeline, which can cool the washing water flowing out of the flue gas scrubbing tower before it is input into the flue gas scrubbing tower.

[0020] Furthermore, the circulation pipeline is equipped with an external drainage pipeline connected to it, which can discharge the washing water in the circulation pipeline as needed.

[0021] The beneficial effects of this utility model are:

[0022] This utility model is reasonably designed, simple in structure, and easy to use. By installing an online analyzer at the exhaust port and a flow regulating controller, the online analyzer, flow meter, and flow regulating valve are configured into a cascade control system. Thus, the setpoint of the flow regulating controller can be adjusted through real-time monitoring by the online analyzer, thereby adjusting the flow regulating valve to change the input of the washing liquid, ensuring that the exhaust gas emissions meet the requirements, and creating favorable conditions for the smooth operation of production. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of this utility model.

[0024] Among them, 1-Flue gas scrubbing tower; 2-Dust scrubbing pump; 3-Second cooler; 4-Scrubbing tower circulation tank; 5-Flue gas scrubbing pump; 6-First cooler; 7-Flow meter; 8-Flow regulating valve; 9-Online analyzer; 10-Flow regulating controller; 11-Scrubbing liquid pipeline; 12-Overflow pipeline; 13-Balancing pipe; 14-Circulation pipeline; 15-Discharge pipe. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] like Figure 1 As shown.

[0027] A self-regulating scrubbing system for bleaching powder flue gas includes a flue gas scrubbing tower 1.

[0028] The flue gas scrubbing tower 1 can be a packed tower or a plate tower. The flue gas scrubbing tower 1 is vertically arranged, with a tail gas discharge port at the top for discharging the scrubbed tail gas into the atmosphere. A washing water discharge port is located at the bottom of the flue gas scrubbing tower 1 for the washing water to flow out. The interior of the flue gas scrubbing tower 1 includes an upper alkaline washing section and a lower water washing section. The alkaline washing section and the water washing section are connected in the gas phase but not in the liquid phase, allowing for separate alkaline and water washing of the bleaching powder flue gas. An online analyzer 9 is installed at the tail gas discharge port to detect the HCl and Cl2 content in the tail gas in real time.

[0029] The alkaline washing section has a washing liquid inlet and an overflow outlet on its side wall. The washing liquid inlet is located at the top of the alkaline washing section, and the overflow outlet is located at the bottom of the alkaline washing section.

[0030] The washing liquid inlet is connected to the outlet of the washing tower circulation tank 4 via a washing liquid pipeline 11. A flue gas scrubbing pump 5 is installed on the washing liquid pipeline 11 to input the washing liquid from the washing tower circulation tank 4 into the alkaline washing section of the flue gas scrubbing tower 1. Simultaneously, a flow meter 7 and a flow regulating valve 8 are also installed on the washing liquid pipeline 11 to detect the flow rate of the washing liquid in the pipeline 11 via the flow meter 7 and to regulate the flow rate via the flow regulating valve 8. Preferably, the flow meter 7 and the flow regulating valve 8 are located near the washing liquid inlet for easy installation and commissioning.

[0031] The overflow port is connected to the return port of the scrubbing tower circulation tank 4 via the overflow pipe 12, so that the scrubbing liquid in the flue gas scrubbing tower 1 can flow back to the scrubbing tower circulation tank 4 for recycling. At the same time, the scrubbing liquid pipe 11 is equipped with a first cooler 6, which can cool the scrubbing liquid from the scrubbing tower circulation tank 4 before it is input into the flue gas scrubbing tower 1 to meet the usage requirements.

[0032] The scrubbing tower circulation tank 4 is equipped with an alkali inlet and a process water inlet, which are respectively connected to the alkali outlet and the process water outlet via pipelines. This allows for the initial input of external alkali and process water into the circulation tank, where they mix to form the scrubbing liquid. After normal operation, alkali and process water are added as needed. Simultaneously, the top of the scrubbing tower circulation tank 4 is connected to the pressure balance port on the flue gas scrubbing tower 1 via a balance pipe 13. This pressure balance port can be located in any gas phase section of the flue gas scrubbing tower 1, ensuring that the pressure inside the scrubbing tower circulation tank 4 matches that inside the flue gas scrubbing tower 1, thus guaranteeing the normal operation of the scrubbing tower circulation tank 4.

[0033] The side wall of the water washing section of the flue gas scrubbing tower 1 is provided with a process water inlet, a circulation port, and a flue gas inlet. Furthermore, the circulation port is located above the process water inlet.

[0034] The process water inlet is connected to the process water outlet via a pipeline, so that external process water can be controlled to be input into the water washing section of the flue gas scrubbing tower 1 to wash the bleaching powder flue gas.

[0035] The flue gas inlet is connected to the flue gas outlet of the bleaching powder unit via a pipeline, so that the flue gas formed by the mixture of dry tail gas and wet tail gas generated in the bleaching powder unit is input into the flue gas scrubbing tower, and then discharged after scrubbing.

[0036] The circulation port is connected to the washing water outlet via a circulation pipe 14, and a dust washing pump 2 is installed on the circulation pipe to re-input the washed water into the flue gas scrubbing tower 1 for recycling. Preferably, the circulation pipe 14 is also equipped with a second cooler 3, which can cool the washing water flowing out of the flue gas scrubbing tower before inputting it back into the flue gas scrubbing tower to meet usage requirements.

[0037] Furthermore, the circulation pipeline 14 is equipped with an external discharge pipeline connected to it, which can controllably discharge the washing water with excessive turbidity in a timely manner. Then, the appropriate process water is added to ensure that the washing process proceeds normally.

[0038] Both the first cooler 6 and the second cooler 3 are cooled by external circulating cooling water.

[0039] The online analyzer 9, flow meter 7, and flow regulating valve 8 form a cascade control system via flow regulating controller 10. The setpoint of the flow regulating controller 10 can be adjusted by the real-time monitoring of the online analyzer 9, thereby regulating the flow regulating valve 8 and changing the input flow of the washing liquid. The flow regulating controller 10 is a general-purpose type using a PID algorithm. The online analyzer 9 can be an infrared spectrometer, an electrochemical sensor, a mass spectrometer, or a laser absorption spectrometer, etc.

[0040] The operation process of this utility model is as follows:

[0041] The bleaching powder flue gas enters the lower part of the flue gas scrubbing tower 1 through a pipeline. At the same time, the scrubbing water flowing out of the scrubbing water outlet is sent out by the dust scrubbing pump 2, and then cooled by the second cooler 3 before flowing back into the flue gas scrubbing tower 1 through the circulation port. It forms a vortex flow in the lower part of the flue gas scrubbing tower 1, which initially removes solid particulate matter and toxic and harmful substances such as Cl2 and HCl from the flue gas.

[0042] Then, the bleaching powder flue gas enters the upper part of the flue gas scrubbing tower 1. At this time, the scrubbing liquid in the scrubbing tower circulation tank is sent to the first cooler 6 by the flue gas scrubbing pump 5. After cooling, it flows through the flow meter 7 and the flow regulating valve 8 in sequence, and then enters the upper part of the flue gas scrubbing tower 1. In the flue gas scrubbing tower 1, it fully contacts the bleaching powder flue gas and absorbs toxic and harmful substances such as Cl2 and HCl in the exhaust gas. Then, the scrubbing liquid flows back to the scrubbing tower circulation tank 4 through the overflow port.

[0043] After two stages of washing, the bleaching powder flue gas is discharged into the atmosphere through the tail gas outlet at the top of the flue gas scrubbing tower 1. During this process, the tail gas is monitored in real time by an online analyzer 9, and the monitoring results are transmitted to the flow regulation controller. The flow regulation controller adjusts the set value according to the monitoring results, and then regulates the flow rate of the washing liquid by controlling the opening of the regulating valve until the tail gas meets the emission standards.

[0044] A specific operational example of this utility model is as follows:

[0045] 35000Nm from bleaching powder unit 3 Flue gas at 0.003 MPaG / h and 80℃ has the following mass composition: H2O: 4.2%, N2: 73.5%, O2: 22.3%, Cl2: 101.7 mg / Nm³. 3 Particulate matter: 30mg / Nm 3 After entering the flue gas scrubbing tower, the flue gas passes through a water scrubbing section and an alkaline scrubbing section in sequence. The circulating water volume in the water scrubbing section is controlled at 100 m³ / h. 3 The washing liquid circulation rate of the alkaline washing section is set to 100m³ / h. 3 / h. When the online analyzer detects that the concentration of Cl2 or HCl in the exhaust gas exceeds the local environmental protection standard, the flow control controller increases the set value of the washing liquid flow rate and controls the flow control valve to increase the washing liquid flow rate until the exhaust gas indicators meet the standard limit requirements.

[0046] This invention uses real-time monitoring by an online analyzer to adjust the setpoint of the flow control controller, thereby adjusting the flow control valve to change the input of the washing liquid, ensuring that the exhaust gas emissions meet the requirements, and creating favorable conditions for smooth production.

[0047] The parts not covered in this utility model are the same as or can be implemented using existing technologies.

Claims

1. A self-regulating scrubbing system for bleaching powder flue gas, comprising a flue gas scrubbing tower, characterized in that, The flue gas scrubbing tower is vertically arranged, with a tail gas emission port at the top and a scrubbing water discharge port at the bottom. Its interior includes an alkaline scrubbing section at the top and a water scrubbing section at the bottom; the tail gas emission port is equipped with an online analyzer. The side wall of the alkaline washing section is provided with a washing liquid inlet and an overflow outlet; the washing liquid inlet is connected to the outlet of the washing tower circulation tank through a washing liquid pipeline; the washing liquid pipeline is provided with a flow meter and a flow regulating valve; the overflow outlet is connected to the return outlet of the washing tower circulation tank through an overflow pipeline. The side wall of the washing section is provided with a process water inlet and a flue gas inlet; the process water inlet is connected to the process water output end through a pipeline; the flue gas inlet is connected to the bleaching powder flue gas output end through a pipeline. The online analyzer, flow meter, and flow regulating valve form a cascade control system through a flow regulating controller. The setpoint of the flow regulating controller can be adjusted by real-time monitoring of the online analyzer, thereby adjusting the flow regulating valve to change the input of washing water.

2. The self-regulating scrubbing system for bleaching powder flue gas according to claim 1, characterized in that, The washing liquid inlet is located at the top of the alkaline washing section; the overflow outlet is located at the bottom of the alkaline washing section.

3. The self-regulating scrubbing system for bleaching powder flue gas according to claim 1, characterized in that, A flue gas scrubbing pump is installed on the washing liquid pipeline.

4. The self-regulating scrubbing system for bleaching powder flue gas according to claim 1, characterized in that, The washing tower circulation tank is equipped with an alkali inlet and a process water inlet; the alkali inlet is connected to the alkali outlet through a pipeline; the process water inlet is connected to the process water outlet through a pipeline.

5. The self-regulating scrubbing system for bleaching powder flue gas according to claim 1, characterized in that, The gas phase section of the flue gas scrubbing tower is provided with a pressure balancing port on its side wall; the pressure balancing port is connected to the top of the scrubbing tower circulation tank through a balancing pipeline.

6. The self-regulating scrubbing system for bleaching powder flue gas according to claim 1, characterized in that, The side wall of the washing section is provided with a circulation port; the circulation port is connected to the washing water outlet through a circulation pipeline; a dust washing pump is provided on the circulation pipeline.

7. The self-regulating scrubbing system for bleaching powder flue gas according to claim 6, characterized in that, The circulation port is located above the process water inlet.

8. The self-regulating scrubbing system for bleaching powder flue gas according to claim 1, characterized in that, The washing liquid pipeline is equipped with a first cooler, which can cool the washing liquid from the washing tower circulation tank before it is fed into the flue gas scrubbing tower.

9. The self-regulating scrubbing system for bleaching powder flue gas according to claim 6, characterized in that, The circulation pipeline is also equipped with a second cooler, which can cool the washing water flowing out of the flue gas scrubbing tower before it is input into the flue gas scrubbing tower.

10. The self-regulating scrubbing system for bleaching powder flue gas according to claim 6, characterized in that, The circulation pipeline is equipped with an external drainage pipeline connected to it, which can discharge the washing water in the circulation pipeline as needed.

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