Exhaust gas treatment system

Abstract

The utility model discloses a tail gas treatment system, which relates to the technical field of tail gas treatment, including: a plurality of absorption towers distributed at intervals, the plurality of absorption towers are used for multiple water washing of waste gas; an alkali washing tower arranged at the tail of the plurality of absorption towers, the alkali washing tower is used for alkali washing of waste gas after water washing by the absorption tower; a concentrated acid delivery pipeline, the concentrated acid delivery pipeline is used for acid neutralization of alkaline waste water discharged from the plurality of absorption towers; a neutralization liquid discharge pipeline, the neutralization liquid discharge pipeline is used for the transmission of neutralized waste water discharged from the absorption tower and the concentrated acid delivery pipeline. The utility model can perform acid washing and alkali washing on the tail gas generated in the process of recovering DMF from DMF waste water, eliminate water-soluble substances and alkaline substances that react with acid in the tail gas, and at the same time cooperate with the acid in the waste liquid of alkali washing to keep the waste water discharged at last neutral, thereby improving the treatment effect of the tail gas, and at the same time, the automation degree is high, the control is convenient, the manpower cost investment is low, and the use demand is met.

Description

Technical Field

[0001] The utility model relates to the technical field of tail gas treatment, in particular to a tail gas treatment system. Background Art

[0002] In the manufacturing process of microfiber leather, DMF (N,N-dimethylformamide) is used as a solvent to dissolve polyurethane resin. In this process, DMF is washed out by utilizing its water-soluble property, resulting in DMF wastewater in the manufacturing process of microfiber leather. In line with the purpose of economy and environmental protection, the company will recycle DMF in the DMF wastewater.

[0003] In the prior art, waste gas is generated in the process of recovering DMF from DMF wastewater. These waste gases are generally alkaline, and direct discharge will cause environmental pollution. Therefore, a tail gas treatment system is generally added to the DMF wastewater recovery and treatment line. However, the current tail gas treatment system generally adopts a water washing method for the waste gas, which is difficult to eliminate the alkalinity in the waste gas, resulting in low treatment quality of the waste gas. For this reason, a tail gas treatment system is proposed. Utility Model Content

[0004] The purpose of the utility model is to provide an exhaust gas treatment system to solve the problems raised in the above background technology.

[0005] To achieve the above purpose, the utility model provides the following technical solution: an exhaust gas treatment system, comprising:

[0006] A plurality of absorption towers are arranged at intervals, and the plurality of absorption towers are used for multiple water washing of the exhaust gas;

[0007] An alkali washing tower arranged at the tail of the multiple absorption towers, the alkali washing tower is used for alkali washing of the waste gas after water washing in the absorption tower, and an alkali water delivery pipeline is provided at the tail of the alkali washing tower, the alkali water delivery pipeline is used to deliver alkaline liquid into the alkali washing tower;

[0008] A concentrated acid delivery pipeline, wherein the concentrated acid delivery pipeline is used to neutralize the alkaline wastewater discharged from multiple absorption towers;

[0009] A neutralization liquid discharge pipeline is used for transmitting neutralization wastewater discharged from the absorption tower and the concentrated acid delivery pipeline.

[0010] Preferably, a gas delivery pipeline is provided between two adjacent absorption towers, the front end of the gas delivery pipeline is connected to the exhaust port at the top of the absorption tower at the front position, the tail end of the absorption tower is connected to the air inlet at the bottom of the absorption tower at the rear position, and the tail end of the gas delivery pipeline on the absorption tower at the tail position is connected to the air inlet at the bottom of the alkali washing tower.

[0011] Preferably, the discharge ports at the bottom of the plurality of absorption towers and alkali washing towers are all provided with waste liquid discharge pipelines, and the waste liquid discharge pipelines are used for discharging waste liquid in the absorption towers and alkali washing towers.

[0012] Preferably, waste liquid reflux pipelines are provided at the liquid inlets at the tops of the side walls of the multiple absorption towers and the alkali washing tower, the waste liquid reflux pipelines on the multiple absorption towers are respectively connected with the concentrated acid delivery pipelines, the waste liquid reflux pipeline on the alkali washing tower is connected with the alkaline water delivery pipeline, a circulation pump is provided between the waste liquid reflux pipeline on the absorption tower and the concentrated acid delivery pipeline, and an alkaline liquid pump is provided between the waste liquid reflux pipeline on the alkali washing tower and the alkaline water delivery pipeline.

[0013] Preferably, the waste liquid discharge pipeline located on the absorption tower is connected to the concentrated acid delivery pipeline, and the waste liquid discharge pipeline located on the alkali washing tower is connected to the alkali water delivery pipeline.

[0014] Preferably, an online pH meter is provided between the circulation pump and the waste liquid reflux pipeline, and between the alkali liquid pump and the waste liquid reflux pipeline. The online pH meter is used to detect the pH value of the liquid discharged from the circulation pump and the alkali liquid pump. A waste liquid discharge pipeline is provided between the online pH meter and the waste liquid reflux pipeline. The tail end of the waste liquid discharge pipeline is connected to the neutralization liquid discharge pipeline. Solenoid valves are provided at the discharge ports of the waste liquid discharge pipeline, the concentrated acid delivery pipeline and the alkali water delivery pipeline, as well as at the waste liquid reflux pipeline, the circulation pump, the waste liquid discharge pipeline and the feed port of the alkali liquid pump.

[0015] Preferably, an alkali preparation tank is provided at the feed port of the alkali water delivery pipeline, and the alkali preparation tank is used to supplement the alkaline liquid in the alkali water delivery pipeline.

[0016] Technical effects and advantages of the utility model:

[0017] The utility model can perform acid washing and alkali washing on the tail gas generated in the process of recovering DMF from DMF wastewater, eliminate water-soluble substances and alkaline substances that react with acid in the tail gas, and cooperate with alkali washing to neutralize the acid in the waste liquid, so that the waste water finally discharged remains neutral, thereby improving the treatment effect of the tail gas. At the same time, the utility model has a high degree of automation, convenient control, low labor cost investment, and meets the use requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the process structure of the utility model.

[0019] In the figure: 100, absorption tower; 101, gas delivery pipeline; 102, waste liquid discharge pipeline; 103, waste liquid reflux pipeline; 104, circulation pump; 200, concentrated acid delivery pipeline; 201, waste liquid discharge pipeline; 202, online pH meter; 300, neutralization liquid discharge pipeline; 400, alkaline water delivery pipeline; 401, alkali preparation tank; 500, alkali washing tower; 501, alkali liquid pump. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] The utility model provides Figure 1 The tail gas treatment system shown in the figure comprises: a plurality of absorption towers 100 distributed at intervals, the plurality of absorption towers 100 are used for multiple water washing of waste gas; an alkali washing tower 500 arranged at the tail of the plurality of absorption towers 100, the alkali washing tower 500 is used for alkali washing of the waste gas after water washing by the absorption tower 100, the tail of the alkali washing tower 500 is provided with an alkaline water delivery pipeline 400, the alkaline water delivery pipeline 400 is used to deliver alkaline liquid into the alkali washing tower 500, and an alkali preparation device is provided at the feed port of the alkaline water delivery pipeline 400 Tank 401, alkali preparation tank 401 is used to supplement the alkaline liquid in the alkaline water delivery pipeline 400; concentrated acid delivery pipeline 200, concentrated acid delivery pipeline 200 is used to neutralize the alkaline wastewater discharged from multiple absorption towers 100, and the concentrated acid solution in the concentrated acid delivery pipeline 200 comes from the barrel in the DMF recovery system in the DMF wastewater; neutralization liquid discharge pipeline 300, neutralization liquid discharge pipeline 300 is used for the transmission of neutralization wastewater discharged from the absorption tower 100 and the concentrated acid delivery pipeline 200;

[0022] It should be noted that, in the above embodiment, in the processing line for recovering DMF from DMF wastewater, the alkaline tail gas discharged from the vacuum system enters the absorption tower 100 at the head end and rises upward from the bottom of the inner cavity of the absorption tower 100. At this time, the acidic liquid transported by the concentrated acid delivery pipeline 200 enters from the top of the side wall of the absorption tower 100 and is sprayed downward through the internal nozzle of the absorption tower 100, and contacts with the rising alkaline tail gas, thereby achieving the cleaning of the tail gas and acid-base neutralization. The tail gas after cleaning enters the subsequent absorption tower 100 for further cleaning. The tail gas after cleaning by multiple absorption towers 100 enters the alkali washing tower 500 for alkali washing, eliminates the acidity in the cleaned tail gas, and makes the gas neutral before discharge. The neutral waste liquid discharged from the absorption tower 100 and the alkali washing tower 500 is discharged into the sewage treatment system through the neutralizing liquid discharge pipeline 300.

[0023] Among them, a gas delivery pipeline 101 is provided between two adjacent absorption towers 100, the front end of the gas delivery pipeline 101 is connected with the exhaust port on the top of the absorption tower 100 at the front position, the tail end of the absorption tower 100 is connected with the air inlet at the bottom of the absorption tower 100 at the rear position, and the tail end of the gas delivery pipeline 101 on the absorption tower 100 at the tail position is connected with the air inlet at the bottom of the alkali washing tower 500. Through the gas delivery pipeline 101, the exhaust gas cleaned by the absorption tower 100 can enter the next absorption tower 100 in turn for further cleaning, and the exhaust gas discharged from the absorption tower 100 at the very tail position can enter the alkali washing tower 500 for alkali washing processing through the gas delivery pipeline 101, thereby realizing the transmission of gas during multiple treatments.

[0024] Furthermore, the discharge ports at the bottom of the multiple absorption towers 100 and the alkali washing tower 500 are all provided with a waste liquid discharge pipeline 102, and the waste liquid discharge pipeline 102 is used to discharge the waste liquid in the absorption tower 100 and the alkali washing tower 500. The liquid inlets at the tops of the side walls of the multiple absorption towers 100 and the alkali washing tower 500 are all provided with a waste liquid reflux pipeline 103. The waste liquid reflux pipelines 103 located on the multiple absorption towers 100 are respectively connected to the concentrated acid delivery pipeline 200, and the waste liquid reflux pipelines 103 located on the alkali washing tower 500 are respectively connected to the concentrated acid delivery pipeline 200. 03 is connected to the alkaline water delivery pipeline 400, a circulation pump 104 is provided between the waste liquid reflux pipeline 103 located on the absorption tower 100 and the concentrated acid delivery pipeline 200, an alkaline liquid pump 501 is provided between the waste liquid reflux pipeline 103 located on the alkali washing tower 500 and the alkaline water delivery pipeline 400, the waste liquid discharge pipeline 102 located on the absorption tower 100 is connected to the concentrated acid delivery pipeline 200, and the waste liquid discharge pipeline 102 located on the alkali washing tower 500 is connected to the alkaline water delivery pipeline 400;

[0025] In the above embodiment, the cleaning liquid discharged from the absorption tower 100 and the alkali washing tower 500 can flow into the corresponding absorption tower 100 and the alkali washing tower 500 along the waste liquid return pipeline 103 through the circulation pump 104 and the alkali liquid pump 501 respectively, so as to achieve the reuse of the waste liquid.

[0026] Next, an online pH meter 202 is provided between the circulation pump 104 and the waste liquid return line 103 and between the alkali liquid pump 501 and the waste liquid return line 103. The online pH meter 202 is used to detect the pH value of the liquid discharged from the circulation pump 104 and the alkali liquid pump 501. A waste liquid discharge line 201 is provided between the online pH meter 202 and the waste liquid return line 103. The tail end of the waste liquid discharge line 201 is connected to the neutralizing liquid discharge line 300. The online pH meter 202 can be used to detect the pH value of the liquid discharged from the circulation pump 104. If the test result is neutral, the liquid can be discharged along the waste liquid discharge line 201 into the neutralizing liquid discharge line 300. If the test result is acidic, the liquid can be discharged through the waste liquid return line 10 3 continues to reflux to the corresponding absorption tower 100, wherein when the pH value detected in the pipeline of the alkali liquid pump 501 of the alkali washing tower 500 is alkaline, it is refluxed to the alkali washing tower 500 through the waste liquid reflux pipeline 103 for reuse, thereby realizing the reuse of the waste liquid, improving the utilization rate, and avoiding the generation of secondary wastewater. The discharge ports of the waste liquid discharge pipeline 102, the concentrated acid delivery pipeline 200 and the alkali water delivery pipeline 400, as well as the waste liquid reflux pipeline 103, the circulation pump 104, the waste liquid discharge pipeline 201 and the feed port of the alkali liquid pump 501 are all provided with solenoid valves. The setting of the solenoid valve, in conjunction with the externally configured control terminal, can facilitate the automatic regulation of multiple pipelines according to the detection results of the online pH meter 202, thereby improving the working quality of the tail gas treatment system.

[0027] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A tail gas treatment system, characterized in that: include: A plurality of absorption towers (100) distributed at intervals, wherein the plurality of absorption towers (100) are used for multiple water washing of waste gas; An alkali washing tower (500) is arranged at the tail of the plurality of absorption towers (100), the alkali washing tower (500) is used for alkali washing the waste gas after being washed by the absorption tower (100), and an alkali water delivery pipeline (400) is provided at the tail of the alkali washing tower (500), and the alkali water delivery pipeline (400) is used for delivering alkaline liquid into the alkali washing tower (500); A concentrated acid delivery pipeline (200), wherein the concentrated acid delivery pipeline (200) is used to neutralize alkaline wastewater discharged from the plurality of absorption towers (100); A neutralization liquid discharge pipeline (300) is used for transporting neutralization wastewater discharged from the absorption tower (100) and the concentrated acid delivery pipeline (200).

2. The exhaust gas treatment system according to claim 1, characterized in that: A gas delivery pipeline (101) is provided between two adjacent absorption towers (100), the front end of the gas delivery pipeline (101) is connected to the exhaust port at the top of the absorption tower (100) at the front position, the rear end of the absorption tower (100) is connected to the air inlet at the bottom of the absorption tower (100) at the rear position, and the rear end of the gas delivery pipeline (101) on the absorption tower (100) at the rear position is connected to the air inlet at the bottom of the alkali washing tower (500).

3. The exhaust gas treatment system according to claim 2, characterized in that: The liquid discharge ports at the bottom of the plurality of absorption towers (100) and the alkali washing tower (500) are all provided with waste liquid discharge pipelines (102), and the waste liquid discharge pipelines (102) are used for discharging waste liquid in the absorption towers (100) and the alkali washing towers (500).

4. The exhaust gas treatment system according to claim 3, characterized in that: A waste liquid reflux pipeline (103) is provided at the liquid inlet of the top of the side wall of the plurality of absorption towers (100) and the alkali washing tower (500); the waste liquid reflux pipeline (103) located on the plurality of absorption towers (100) is respectively connected to the concentrated acid delivery pipeline (200); the waste liquid reflux pipeline (103) located on the alkali washing tower (500) is connected to the alkaline water delivery pipeline (400); a circulation pump (104) is provided between the waste liquid reflux pipeline (103) located on the absorption tower (100) and the concentrated acid delivery pipeline (200); and an alkaline liquid pump (501) is provided between the waste liquid reflux pipeline (103) located on the alkali washing tower (500) and the alkaline water delivery pipeline (400).

5. The exhaust gas treatment system according to claim 4, characterized in that: The waste liquid discharge pipeline (102) located on the absorption tower (100) is connected to the concentrated acid delivery pipeline (200), and the waste liquid discharge pipeline (102) located on the alkali washing tower (500) is connected to the alkali water delivery pipeline (400).

6. The exhaust gas treatment system according to claim 5, characterized in that: An online pH meter (202) is provided between the circulation pump (104) and the waste liquid reflux pipeline (103), and between the alkali liquid pump (501) and the waste liquid reflux pipeline (103). The online pH meter (202) is used to detect the acidity and alkalinity of the liquid discharged from the circulation pump (104) and the alkali liquid pump (501). A waste liquid discharge pipeline (201) is provided between the online pH meter (202) and the waste liquid reflux pipeline (103). The tail end of the waste liquid discharge pipeline (201) is connected to the neutralization liquid discharge pipeline (300). Electromagnetic valves are provided at the discharge ports of the waste liquid discharge pipeline (102), the concentrated acid delivery pipeline (200) and the alkali water delivery pipeline (400), and at the feed ports of the waste liquid reflux pipeline (103), the circulation pump (104), the waste liquid discharge pipeline (201) and the alkali liquid pump (501).

7. The exhaust gas treatment system according to claim 6, characterized in that: An alkali preparation tank (401) is provided at the feed port of the alkali water delivery pipeline (400), and the alkali preparation tank (401) is used to supplement the alkaline liquid in the alkali water delivery pipeline (400).

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