Tail gas alkali washing device

Abstract

The utility model relates to the technical field of desulfurization post-treatment equipment, in particular to a tail gas alkali washing device which comprises an alkali liquor supply assembly, a reverse spraying assembly and an alkali washing assembly, sulfur dioxide in the tail gas is absorbed and converted by adopting alkali liquor, so that the tail gas post-treatment effect is improved; the alkali liquor supply assembly is arranged to provide alkali liquor in the alkali washing process, tail gas needing alkali washing aftertreatment enters the reverse spraying cavity of the reverse spraying assembly, the alkali liquor sprayed through multiple sets of reverse spraying pipes and reverse spraying nozzles arranged in the reverse spraying cavity makes reverse contact with the tail gas multiple times, and sulfur dioxide in the tail gas is absorbed through multi-stage absorption; the treatment effect is excellent; the tail gas flowing out of the reverse spraying cavity enters an alkaline washing tower of the alkaline washing assembly, sulfur dioxide contained in the tail gas is absorbed to the maximum extent through alkaline liquor sprayed out of an alkaline liquor sprayer in the alkaline washing tower, the content of sulfur dioxide in the tail gas discharged after the tail gas is treated in the after-treatment alkaline washing process is extremely low, and environmental friendliness is higher.

Description

Technical Field

[0001] The utility model relates to the technical field of desulfurization post-processing equipment, in particular to a tail gas alkali washing device. Background Art

[0002] Acidic gases such as hydrogen sulfide are produced in the production process of petrochemical, coal chemical, natural gas, sulfuric acid plants and other chemical fields. These acidic gases are generally treated by desulfurization process to convert H2S into elemental sulfur as much as possible. Desulfurization equipment is a device used to treat these acidic gases containing harmful sulfur-containing substances. The commonly used desulfurization process is to use oxidation to convert harmful sulfur-containing substances in acidic gases into elemental sulfur. During the acid gas desulfurization process, the SO2 concentration in the tail gas after treatment is a continuous monitoring item and the monitoring concentration requirements are becoming more and more stringent. The treatment effect of the commonly used desulfurization equipment is not ideal. There is a lot of SO2 in the tail gas, and the sulfur dioxide concentration monitoring is unqualified. Therefore, based on the above problems, the existing technology needs to be further improved. Utility Model Content

[0003] The purpose of the utility model is to provide a tail gas alkali washing device, which uses alkali liquid to absorb the tail gas in multiple stages in the reverse spray chamber to eliminate sulfur dioxide in the tail gas, and then absorbs it again through the alkali liquid in the alkali washing tower, that is, the tail gas post-treatment effect is better after multiple absorption. To solve the existing technical problems existing in the above background technology.

[0004] In order to solve the above-mentioned technical problems, the technical solution provided by the utility model is as follows: an exhaust gas alkali washing device is provided, comprising an alkali solution supply component, a reverse spray component and an alkali washing component, wherein the alkali solution supply component provides alkali solution for the reverse spray component and the alkali washing component; the reverse spray component comprises a reverse spray chamber and at least one group of reverse spray pipes, the top of the reverse spray chamber is provided with an exhaust gas inlet, the head end of the reverse spray pipe is connected to the alkali solution supply component, the end is provided in the reverse spray chamber and a reverse nozzle is provided at the end; the alkali washing component comprises an alkali washing tower, the alkali washing tower is connected to the end of the reverse spray chamber, and an alkali solution sprayer is provided on the inner wall of the alkali washing tower.

[0005] On the basis of the above technical scheme, it also includes a wastewater treatment component arranged at the end of the alkali washing component, and the wastewater treatment component includes a wastewater tank, a wastewater buffer tank and a wastewater pump. The wastewater tank is connected to the end of the alkali washing tower through a pipeline, and the end of the wastewater tank is connected to the wastewater buffer tank, and the wastewater buffer tank is connected to the sewage treatment device through the wastewater pump.

[0006] On the basis of the above technical solution, the alkali solution supply assembly includes an alkali solution tank and an alkali solution pump. The alkali solution tank is used to store alkali solution, and the alkali solution tank is connected to the reverse spray assembly through the alkali solution pump.

[0007] Based on the above technical solution, the reverse spray assembly includes a first-level reverse spray pipe and a second-level reverse spray pipe and are arranged in sequence from top to bottom in the reverse spray chamber. The first-level reverse spray pipe and the second-level reverse spray pipe are both provided with a circulation pump, and the first-level reverse spray pipe and the second-level reverse spray pipe are both connected to the alkali solution tank.

[0008] On the basis of the above technical solution, a circulating liquid cooler is further provided on the first-level reverse spray pipe, and the circulating liquid cooler is arranged between the circulating pump and the reverse spray nozzle.

[0009] Based on the above technical solution, the alkali washing component also includes a demister, and the demister is arranged at the inner top of the alkali washing tower and is provided in plurality.

[0010] On the basis of the above technical solution, a cleaning nozzle is further provided on the inner wall of the alkali washing tower and is correspondingly arranged at the bottom end of the demister, and the cleaning nozzle is connected to the desalted water supply tank through a pipeline.

[0011] On the basis of the above technical solution, it also includes a main fan, which is connected to the bottom end of the alkali washing tower through a first pipeline.

[0012] The beneficial effects of the technical solution provided by the utility model are:

[0013] The present application provides a tail gas alkali washing device, which performs alkali washing treatment on the tail gas after the previous process such as the thermal incineration process, and uses alkali liquid to absorb and convert the sulfur dioxide in the tail gas, so as to improve the treatment effect of the tail gas post-treatment; an alkali liquid supply component is provided to provide the alkali liquid in the alkali washing process, and the tail gas that needs alkali washing post-treatment enters the reverse spray chamber of the reverse spray component, and the alkali liquid sprayed by the multiple groups of reverse spray pipes and reverse nozzles arranged in the reverse spray chamber is in reverse contact with the tail gas for multiple times, that is, the sulfur dioxide in the tail gas is absorbed through multi-stage absorption, and the treatment effect is excellent; the tail gas flowing out of the reverse spray chamber then enters the alkali washing tower of the alkali washing component, and the alkali liquid sprayed by the alkali liquid sprayer in the alkali washing tower further absorbs the sulfur dioxide in the tail gas, so as to achieve the maximum absorption of the sulfur dioxide contained in the tail gas, and the exhaust gas discharged after treatment has an extremely low sulfur dioxide content, and is more environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0015] Figure 2 It is a structural schematic diagram of the reverse spray component and the alkali washing component in the utility model;

[0016] Figure 3 It is a structural schematic diagram of the wastewater treatment component in the utility model; DETAILED DESCRIPTION

[0017] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0018] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0019] In the description of the present invention, it should be understood that the terms "left", "right", "front", "back", "top", "bottom", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0020] like Figures 1 to 3 As shown, an exhaust gas alkali washing device includes an alkali solution supply component, a reverse spray component and an alkali washing component, wherein the alkali solution supply component provides alkali solution for the reverse spray component and the alkali washing component; the reverse spray component includes a reverse spray chamber 20 and at least one group of reverse spray pipes, the top of the reverse spray chamber 20 is provided with an exhaust gas inlet 21, the head end of the reverse spray pipe is connected to the alkali solution supply component, the end is arranged in the reverse spray chamber 20 and the end is provided with a reverse nozzle 22; the alkali washing component includes an alkali washing tower 30, the alkali washing tower 30 is connected to the end of the reverse spray chamber 20, and an alkali solution sprayer 31 is provided on the inner wall of the alkali washing tower 30.

[0021] The present application provides a tail gas alkali washing device, which performs alkali washing treatment on the tail gas after the previous process such as the thermal incineration process, and uses alkali liquid to absorb and convert the sulfur dioxide in the tail gas, so as to improve the treatment effect of the tail gas post-treatment; by setting an alkali liquid supply component to provide alkali liquid in the alkali washing process, the tail gas gas that needs alkali washing post-treatment enters the reverse spray chamber 20 of the reverse spray component, and the alkali liquid sprayed by the multiple groups of reverse spray pipes and reverse nozzles 22 arranged in the reverse spray chamber 20 is in reverse contact with the tail gas for multiple times, that is, the sulfur dioxide in the tail gas is absorbed by multi-stage absorption, and the treatment effect is excellent; the tail gas flowing out of the reverse spray chamber 20 enters the alkali washing tower 30 of the alkali washing component again, and the alkali liquid sprayed by the alkali liquid sprayer 31 in the alkali washing tower 30 further absorbs the sulfur dioxide in the tail gas, so as to achieve the maximum absorption of the sulfur dioxide contained in the tail gas, and the exhaust gas discharged after treatment has an extremely low sulfur dioxide content, and is more environmentally friendly.

[0022] Preferably, sodium hydroxide solution is used as the alkaline washing solution, which can react rapidly with SO2 in the tail gas; under the action of excess sodium hydroxide, most of the SO2 in the tail gas is converted into sulfite; the main reactions in the reverse spray chamber and the alkaline washing tower are: 2NaOH+SO2→Na2SO3+H2O+reaction heat; Na2SO3+SO2+H2O→2NaHSO3.

[0023] On the basis of the above technical solution, a wastewater treatment component is also included at the end of the alkali washing component, and the wastewater treatment component includes a wastewater tank 40, a wastewater buffer tank 41 and a wastewater pump 42. The wastewater tank 40 is connected to the end of the alkali washing tower 30 through a pipeline, and the end of the wastewater tank 40 is connected to the wastewater buffer tank 41, and the wastewater buffer tank 41 is connected to the sewage treatment device 43 through the wastewater pump 42.

[0024] By providing a wastewater treatment component at the end of the alkali washing tower 30, the waste liquid after the tail gas alkali washing is collected and treated to avoid environmental pollution; specifically, the waste liquid in the alkali washing tower enters the wastewater tank and is pumped to the sewage treatment device 43 through the wastewater pump 42 for waste liquid and sewage treatment, wherein the wastewater pump 42 provides power for waste liquid discharge, and the wastewater buffer tank 41 can also provide buffer storage for the waste liquid in the wastewater tank 40, to avoid affecting the timely treatment of the waste liquid when there is a lot of waste liquid, and to ensure the smoothness of the post-treatment of the waste liquid.

[0025] On the basis of the above technical solution, the alkali solution supply component includes an alkali solution tank 10 and an alkali solution pump 11 . The alkali solution tank 10 is used to store alkali solution. The alkali solution tank 10 is connected to the reverse spray component through the alkali solution pump 11 .

[0026] The alkali washing tank 10 in this embodiment stores alkali solution, which is pumped into the reverse spray chamber 20 through the pipeline and the alkali washing pump 11 on the pipeline, so as to absorb the sulfur dioxide in the tail gas and realize the alkali washing process.

[0027] Preferably, in this embodiment, the alkali solution is a 30% sodium hydroxide solution and the pH value is maintained at 7-9; more preferably, the pH value of the alkali solution is maintained at 7.2. Specifically, an alkali solution metering pump can be used to replenish 30% of the alkali solution in the alkali washing tower in real time so that the pH value of the alkali solution remains stable during the tail gas treatment process. The pH value of 7.2 is the best value for absorbing the most sulfur dioxide without absorbing a large amount of carbon dioxide. More preferably, the pH is controlled by a pH meter, and the liquid level is controlled by a liquid level meter. The density, pH, and liquid level meter coordinately control the balance of the liquid level, density, and pH in the alkali washing tower to ensure the absorption effect of sulfur dioxide. There may be a large amount of carbon dioxide in the exhaust gas. If the pH value of the solution is too high, it will react with NaOH to generate Na2CO3, which will consume a large amount of sodium hydroxide. If the pH value of the solution is too low, it will not be enough to remove SO2 in the exhaust gas, so the pH value of the alkali solution is controlled within the range of 7 to 9; 2NaOH+CO2→Na2CO3+H2O; different reactions of sulfur dioxide and sodium carbonate under different conditions: 2Na2CO3+SO2+H2O→2NaHCO3+Na2SO3; Na2CO3+SO2→CO2+Na2SO3; Na2CO3+2SO2+H2O→CO2+2NaHSO3.

[0028] Based on the above technical solution, the reverse spray assembly includes a first-level reverse spray pipe 23 and a second-level reverse spray pipe 24 and are arranged in sequence from top to bottom in the reverse spray chamber 20. A circulation pump 25 is provided on the first-level reverse spray pipe 23 and the second-level reverse spray pipe 24. The first-level reverse spray pipe 23 and the second-level reverse spray pipe 24 are both connected to the alkali liquid tank 10.

[0029] On the basis of the above technical solution, a circulating liquid cooler 26 is further provided on the first-level reverse spray pipe 23 , and the circulating liquid cooler 26 is arranged between the circulating pump 25 and the reverse spray nozzle 22 .

[0030] In the present embodiment, a multi-stage reverse spraying pipe is provided in the reverse spraying chamber 20 and a reverse nozzle 22 is provided at the end of each reverse spraying pipe. The circulating alkaline solution flowing therein performs multi-stage absorption on the tail gas, so that the absorption effect of the sulfur-containing substances is better, the post-treatment effect is improved, and serious pollution to the environment is avoided. Specifically, the tail gas generated by the previous treatment section, such as the thermal incineration section, enters the reverse spray chamber, and a circulating liquid cooler 26 is provided at the outlet of the circulating pump on the first-level reverse spray pipe 23 to cool the circulating alkali solution to below 45°C. The cooled alkali solution is used to adiabatically quench the hot flue gas, and the hot flue gas is cooled to 56°C, and is sprayed out through the reverse nozzle on the first-level reverse spray pipe 23 to absorb SO2 in the tail gas; then the alkali solution circulating in the circulating pump on the second-level reverse spray pipe 24 is sprayed out through the reverse nozzle on the second-level reverse spray pipe 24 to further absorb SO2 in the tail gas; then the treated tail gas enters the alkali washing tower 30, and the alkali solution sprayer 31 in the alkali washing tower 30 further absorbs SO2 in the tail gas to complete the overall tail gas alkali washing process. In a preferred embodiment, the alkali solution in the alkali washing sprayer 31 is supplied through one of the branches of the second-level reverse spray pipe 24, and the other branch is supplied to the reverse spray chamber 20 for use in the second-level reverse spray.

[0031] On the basis of the above technical solution, the alkali washing component further includes a demister 32 , and the demister 32 is arranged at the top of the alkali washing tower 30 and is provided in plurality.

[0032] By arranging a plurality of demisters 32 in the alkali washing tower 30, gas-liquid separation is performed before the tail gas after alkali washing is discharged into the air, and the exhaust gas discharge is more environmentally friendly; in this embodiment, the demister 32 is preferably two groups, that is, a two-stage demister is used to separate the sodium sulfite / sodium sulfate droplets entrained in the gas from the gas, and then the tail gas is discharged outdoors through the chimney 34 through the heat exchanger 33.

[0033] On the basis of the above technical solution, a cleaning nozzle 35 is further provided on the inner wall of the alkali washing tower 30 and is correspondingly arranged at the bottom end of the demister 32 . The cleaning nozzle 35 is connected to the desalted water supply tank 36 through a pipeline.

[0034] Preferably, in this embodiment, a cleaning nozzle 35 is provided. During the long-term operation of the alkali washing tower 30, the demister 32 needs to be cleaned in time. Desalted water is used to flush the demister 32 through the cleaning nozzle 35, wherein the desalted water is passed through the desalted water supply tank 36 and the pipeline into the cleaning nozzle 35 to ensure its gas-liquid separation effect. More preferably, the demister 32 is provided with two groups, and the cleaning nozzle 35 is also provided with two groups accordingly.

[0035] On the basis of the above technical solution, a main fan 50 is further included, and the main fan 50 is connected to the bottom end of the alkali washing tower 30 through a first pipeline 51.

[0036] A main blower 50 is provided, which is connected to the inside of the alkali washing tower 30 through a first pipeline 51, and air is introduced from the bottom of the alkali washing tower 30 to generate appropriate bubbles. Oxygen reacts with sodium sulfite and sodium bisulfite in the circulating liquid to generate sodium sulfate. The main reactions involved are: 2NaHSO3+O2→Na2SO4+H2O, 2Na2SO3+O2→2Na2SO4, thereby avoiding environmental pollution. At the same time, the sodium sulfate is discharged after the concentration exceeds the set value.

[0037] It should be noted that the head end and the end end mentioned above are defined according to the flow direction of the medium such as liquid, gas or steam in the pipeline, which is only for the convenience of understanding and description of the technical solution and does not constitute a limitation of the present application.

[0038] The basic principle and main features of the utility model are shown and described above. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments. Therefore, the embodiments should be regarded as exemplary and non-restrictive. The scope of the utility model is limited by the appended claims rather than the above description. Therefore, it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the utility model.

[0039] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A tail gas alkali washing device, characterized in that: The invention comprises an alkali solution supply component, a reverse spray component and an alkali washing component, wherein the alkali solution supply component provides alkali solution for the reverse spray component and the alkali washing component; the reverse spray component comprises a reverse spray chamber (20) and at least one group of reverse spray pipes, the top of the reverse spray chamber (20) is provided with an exhaust gas inlet (21), the head end of the reverse spray pipe is connected to the alkali solution supply component, the end end is arranged in the reverse spray chamber (20) and the end end is provided with a reverse nozzle (22); the alkali washing component comprises an alkali washing tower (30), the alkali washing tower (30) is connected with the end of the reverse spray chamber (20), and an alkali solution sprayer (31) is arranged on the inner side wall of the alkali washing tower (30).

2. The tail gas alkali washing device according to claim 1, characterized in that: The invention also comprises a wastewater treatment component arranged at the end of the alkali washing component, the wastewater treatment component comprising a wastewater tank (40), a wastewater buffer tank (41) and a wastewater pump (42), the wastewater tank (40) being connected to the end of the alkali washing tower (30) through a pipeline, the end of the wastewater tank (40) being communicated with the wastewater buffer tank (41), and the wastewater buffer tank (41) being connected to a sewage treatment device (43) through the wastewater pump (42).

3. The tail gas alkali washing device according to claim 1, characterized in that: The alkali solution supply assembly comprises an alkali solution tank (10) and an alkali solution pump (11); the alkali solution tank (10) is used to store alkali solution; the alkali solution tank (10) is connected to the reverse spray assembly via the alkali solution pump (11).

4. A tail gas alkali washing device according to claim 3, characterized in that: The reverse spray assembly comprises a primary reverse spray pipe (23) and a secondary reverse spray pipe (24) which are sequentially arranged from top to bottom in the reverse spray chamber (20); a circulation pump (25) is arranged on each of the primary reverse spray pipe (23) and the secondary reverse spray pipe (24); and each of the primary reverse spray pipe (23) and the secondary reverse spray pipe (24) is connected to the alkali liquid tank (10).

5. The tail gas alkali washing device according to claim 4, characterized in that: The first-stage reverse spray pipe (23) is also provided with a circulating liquid cooler (26), and the circulating liquid cooler (26) is arranged between the circulating pump (25) and the reverse spray nozzle (22).

6. The tail gas alkali washing device according to claim 1, characterized in that: The alkali washing component further comprises a demister (32), wherein a plurality of demisters (32) are arranged at the top of the interior of the alkali washing tower (30).

7. The tail gas alkali washing device according to claim 6, characterized in that: A cleaning nozzle (35) is also provided on the inner side wall of the alkali washing tower (30) and is correspondingly arranged at the bottom end of the demister (32). The cleaning nozzle (35) is connected to the desalted water supply tank (36) through a pipeline.

8. The tail gas alkali washing device according to claim 2, characterized in that: It also includes a main fan (50), which is connected to the bottom end of the alkali washing tower (30) through a first pipeline (51).

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