High-purity nitric oxide tail gas absorption device

Abstract

The high-purity nitric oxide tail gas absorption device comprises a gas washing unit and a reaction unit, the gas washing unit comprises a plurality of absorption towers which are connected in series, the absorption towers comprise a water washing tower and an alkaline washing tower, liquid inlet valves are arranged on the upper sides of the water washing tower and the alkaline washing tower, and liquid discharge valves are arranged on the lower sides of the water washing tower and the alkaline washing tower. A circulating spraying system is arranged in the absorption tower; the reaction unit comprises a buffer tank I arranged on the front side of the water washing tower and a buffer tank II arranged on the front side of the alkaline washing tower; the concentration detection system comprises a detection assembly, and the detection assembly is used for detecting the pH value in the absorption tower. The device has the beneficial effects that the absorption efficiency is high, the absorption is thorough, the equipment is simple, and the operation is convenient.

Description

TECHNICAL FIELD

[0001] The utility model relates to high -purity chemical technology field, specifically to a kind of high-purity nitric oxide tail gas absorption device. BACKGROUND

[0002] High-purity nitric oxide is widely used in medicine, scientific research, environmental protection, fine chemical and electronic field as an electronic gas.In the production process of high-purity nitric oxide, production device purge tail gas, analysis tail gas and unqualified product discharge need to be disposed safely.

[0003] Tail gas components mainly include nitric oxide (NO), nitrogen dioxide (NO 2) And nitrous oxide (N2O), these gases have great damage to the environment, they are one of the main substances forming acid rain, and they are important substances forming atmospheric photochemical smog and an important factor consuming ozone (O 3) Therefore, they must be treated.

[0004] The existing nitrogen oxide waste gas treatment methods generally include selective non-catalytic reduction method (SNCR method), selective catalytic reduction method (SCR method), adsorption method and absorption method, etc.SNCR method and SCR method reduce nitrogen oxide to nitrogen and water by reducing agent ammonia or urea at high temperature with or without catalyst, and finally harmless discharge, which is generally applied to nitrogen oxide treatment of thermal power plant;Adsorption method is generally suitable for the case of less nitrogen oxide;Absorption method uses water, alkali and acid for absorption conversion, and generally uses alkali solution for absorption, which has the advantages of wide application range and simple equipment, but due to high content of nitric oxide (generally NO>99%) in the absorption process, it may lead to incomplete absorption, emission to atmosphere and environmental pollution. INVENTION CONTENTS

[0005] To solve the above technical problems, the utility model provides a kind of high-purity nitric oxide tail gas absorption device, absorption rate is high, easy operation, wide application range.

[0006] Specifically, the utility model discloses a kind of high-purity nitric oxide tail gas absorption device, comprising: gas washing unit and reaction unit, the gas washing unit includes several series connection setting absorption tower, including water washing tower and alkali washing tower, water washing tower and the upper side of alkali washing tower is provided with liquid inlet valve, and the lower side is provided with liquid outlet valve, and the absorption tower is provided with circulating spray system;The reaction unit includes buffer tank one set in the front side of water washing tower and buffer tank two set in the front side of the alkali washing tower;Further including concentration detection system, including detection component, the detection component is used to detect the PH value in the absorption tower.

[0007] The beneficial effects of the above technical solution are high absorption efficiency, complete absorption, simple equipment and easy operation.

[0008] Further, the buffer tank one and the buffer tank two are provided with an air inlet and a tail gas inlet, and an air outlet is arranged at the top.

[0009] The beneficial effects of the above technical scheme are that the two buffer tanks make the nitrogen monoxide in the tail gas react with the oxygen in the air to generate nitrogen dioxide, reducing the content of nitrogen monoxide and facilitating the complete removal of nitrogen monoxide in the tail gas.

[0010] Further, a partition is arranged inside the buffer tank one and the buffer tank two, and a plurality of holes are arranged on the partition.

[0011] The beneficial effects of the above technical scheme are that the partition plays a blocking role, and after being fully mixed with the oxygen in the air, the air enters the absorption tower through the holes, and the exhaust gas is absorbed.

[0012] Further, the reaction unit further comprises a plurality of air blowers, the air blowers are connected with the buffer tank one and the buffer tank two through air inlet pipes, the air inlet pipes extend into the buffer tank one and the buffer tank two, and the end portions are bent downward.

[0013] The beneficial effects of the above technical scheme are that the air blowers blow air into the buffer tank one and the buffer tank two, the tail gas is reacted with the air, the content of nitrogen monoxide in the tail gas is reduced, and the subsequent absorption is facilitated.

[0014] Further, a one-way valve is arranged at the tail gas inlet of the buffer tank one.

[0015] The beneficial effects of the above technical scheme are that the one-way valve can control the opening and closing of the pipeline, and when maintenance is needed, the one-way valve is closed to cut off the input of the tail gas.

[0016] Further, the water washing tower comprises a water washing tower one and a water washing tower two, an air inlet is arranged at the bottom of the water washing tower one and connected with the buffer tank one, and an air inlet arranged at the bottom of the water washing tower two is connected with an outlet arranged on the water washing tower one.

[0017] The beneficial effects of the above technical scheme are that two water washing towers are arranged to perform water washing twice, ensuring the water washing quality.

[0018] Further, the circulating spray system comprises a spray head arranged at the top of the absorption tower and a containing tank arranged at the bottom of the absorption tower, the containing tank is connected with the spray head through a connecting pipe, and a circulating pump is arranged on the connecting pipe.

[0019] The beneficial effects of the above technical scheme are that the spray head is arranged to fully mix the liquid in the absorption tower with the entering tail gas, the liquid enters the containing tank, and is driven in circulation by the circulating pump.

[0020] Further, the caustic washing tower comprises a caustic washing tower I and a caustic washing tower II, the caustic washing tower II is connected with the caustic washing tower I, and a chimney is connected with the caustic washing tower II.

[0021] The beneficial effects of the above technical scheme are that the two gap towers are arranged to convert and absorb the nitrogen monoxide and nitrogen dioxide in the tail gas, thereby avoiding environmental pollution. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the embodiments or prior art description will be briefly introduced.

[0023] Fig. 1 is a connection schematic diagram of the high-purity nitrogen monoxide tail gas absorption device

[0024] Fig. 2 is a structure schematic diagram of the buffer tank I

[0025] Fig. 3 is a structure schematic diagram of the absorption tower

[0026] The labels involved in the drawings are as follows:

[0027] Buffer tank I 1; air inlet 11; tail gas inlet 12; gas outlet 13; partition 14; gas inlet pipe 15; one-way valve 16; buffer tank II 2; liquid inlet valve 21; liquid outlet valve 22; detection assembly 3; air blower 4; water washing tower I 5; water washing tower II 6; spray head 7; containing groove 71; connecting pipe 72; circulating pump 73; caustic washing tower I 8; caustic washing tower II 9; chimney 91; fan 92. DETAILED DESCRIPTION

[0028] The present application will be further described in detail below with reference to the drawings.

[0029] As Figs. 1-3 shown, the present application discloses a high-purity nitrogen monoxide tail gas absorption device, comprising: a gas washing unit and a reaction unit, the gas washing unit comprises a plurality of absorption towers arranged in series, comprising a water washing tower and a caustic washing tower, the water washing tower and the caustic washing tower are provided with a liquid inlet valve 21 on the upper side and a liquid outlet valve 22 on the lower side; the liquid inlet valve 21 on the upper side is respectively used for passing water and lye into the water washing tower and the caustic washing tower, and a circulating spray system is arranged in the absorption tower; the reaction unit comprises a buffer tank I 1 arranged on the front side of the water washing tower and a buffer tank II 2 arranged on the front side of the caustic washing tower; further comprising a concentration detection system, comprising a detection assembly 3, the detection assembly 3 is a pH meter, the detection assembly 3 is used for detecting the pH value in the absorption tower, the water washing tower and the caustic washing tower are further provided with a liquid level meter, and the water washing tower and the caustic washing tower are both provided with a filler.

[0030] The beneficial effect of the above technical scheme is high absorption efficiency, complete absorption, simple equipment and convenient operation.

[0031] In some embodiments, the buffer tank one 1 and the buffer tank two 2 are provided with an air inlet 11 and a tail gas inlet 12, and the top is provided with an air outlet 13. The tail gas inlet 12 is arranged at the bottom of the buffer tank one 1 and the buffer tank two 2 to introduce tail gas. The air inlet 11 is connected with the air blower 4 to introduce air. The air blower 4 is connected with the buffer tank one 1 and the buffer tank two 2 through an air inlet pipe 15. The air inlet pipe 15 extends into the inside of the buffer tank one 1 and the buffer tank two 2, and the end is bent downward. The air enters through the air inlet pipe 15, and due to the downward bending of the air inlet end, the entered air moves downward and mixes with the tail gas entering through the bottom, and then enters into the water washing tower and the alkali washing tower through the air outlet 13 on the upper side.

[0032] Further, a partition plate 14 is arranged inside the buffer tank one 1 and the buffer tank two 2. The partition plate 14 is provided with a plurality of holes. The partition plate 14 is installed inside the buffer tank one 1 and the buffer tank two 2, and can be fixed by screws or clamping blocks. The partition plate 14 is located above the air inlet 11. The tail gas and the air mix at the lower side of the buffer tank and then are discharged through the holes. The holes can control the flow rate of the gas, so that the air and the tail gas are fully mixed, and the content of nitrogen monoxide in the tail gas is reduced.

[0033] The beneficial effect of the above technical scheme is that the partition plate 14 plays a blocking role. After fully mixing with the oxygen in the air, the tail gas enters into the absorption tower through the holes.

[0034] In some embodiments, a one-way valve 16 is arranged at the tail gas inlet 12 of the buffer tank one 1.

[0035] The beneficial effect of the above technical scheme is that the one-way valve 16 can control the on-off of the pipeline. When maintenance is needed, the one-way valve 16 is closed to cut off the input of the tail gas.

[0036] In some embodiments, the water washing tower includes a water washing tower one 5 and a water washing tower two 6. The water washing tower one 5 is provided with an air inlet at the bottom and is connected with the buffer tank one 1. The water washing tower two 6 is provided with an air inlet at the bottom and is connected with an outlet arranged on the water washing tower one 5.

[0037] The beneficial effect of the above technical scheme is that two water washing towers are arranged to perform water washing twice, so as to ensure the water washing quality. The water washing tower removes most of the nitrogen dioxide, generates less nitrogen monoxide in the process, and the nitrogen monoxide enters the buffer tank two 2 to react with oxygen to generate nitrogen dioxide. A small amount of nitrogen dioxide enters the alkali washing tower and is finally absorbed.

[0038] Further, the circulating spray system comprises a spray head 7 arranged at the top of the absorption tower and a containing tank 71 arranged at the bottom of the absorption tower, the containing tank 71 is connected with the spray head 7 through a connecting pipe 72, a circulating pump 73 is arranged on the connecting pipe 72, the spray head 7 is arranged to fully mix the liquid in the absorption tower with the entering tail gas, the liquid enters the containing tank 71, and the PH meter is arranged in the containing tank 71 to detect the PH value of the liquid in the containing tank 71 and transmit the value to the control system, and the control system controls the on-off of the liquid inlet valve 21 and the liquid outlet valve 22.

[0039] Further, the alkali washing tower comprises an alkali washing tower one 8 and an alkali washing tower two 9, the alkali washing tower two 9 is connected with the alkali washing tower one 8, the alkali washing tower two 9 is connected with a chimney 91, a fan 92 is arranged between the alkali washing tower two 9 and the chimney 91, the fan 92 sends the remaining oxygen, nitrogen and other gases generated after absorption to the chimney 91 for discharge, and the discharged tail gas does not pollute the environment, and the alkali concentration of the alkali washing tower is between 5% and 20%.

[0040] The beneficial effects of the above technical scheme are that the arrangement of the two gap towers ensures the conversion and absorption of nitrogen monoxide and nitrogen dioxide in the tail gas, thereby avoiding environmental pollution.

[0041] In the whole working process, firstly, the tail gas enters the buffer tank one 1 through a pipeline, and the air blower 4 blows air into the buffer tank one 1, and after full mixing, enters the water washing tower one 5 and the water washing tower two 6 in turn, and then enters the buffer tank two 2, the buffer tank two 2 is also blown by the air blower 4, and then enters the alkali washing tower in turn, and after reaction and absorption, is discharged through the chimney 91 to complete the absorption process, and the water washing tower and the alkali washing tower are provided with a circulating spray system to ensure complete absorption.

[0042] At the same time, when the water washing tower absorbs the acidic gas NO2, nitric acid is generated, and the acidic concentration of the water washing liquid gradually increases, when the acidic concentration reaches 5%, the lower liquid outlet valve 22 of the water washing tower is automatically opened, and the upper water washing liquid inlet valve 21 is opened at the same time, and when the acidic concentration decreases to 0.5%, the liquid outlet valve 22 and the water washing inlet valve are closed (this process ensures that the tower liquid level is greater than 2 / 3).

[0043] When the tail gas is not completely absorbed by the water washing tower, the alkali washing tower will completely absorb the remaining tail gas, and with the absorption process, the alkali concentration will gradually decrease, when the alkali concentration decreases to 5%, the lower liquid outlet valve 22 of the alkali washing tower is automatically opened, and the upper alkali inlet valve is opened at the same time, and when the acidic concentration increases to 20%, the liquid outlet valve 22 and the liquid inlet valve 21 are closed (this process ensures that the tower liquid level is greater than 2 / 3).

[0044] For those skilled in the art, without departing from the creative concept of the present application, a number of modifications and improvements can be made, which all belong to the protection scope of the present application.

Claims

1. A high-purity nitrogen monoxide tail gas absorption device, characterized in that: include: A scrubbing unit and a reaction unit, wherein the scrubbing unit comprises a plurality of absorption towers arranged in series, including a water scrubbing tower and an alkali scrubbing tower, wherein the water scrubbing tower and the alkali scrubbing tower are provided with a liquid inlet valve (21) on their upper sides and a liquid discharge valve (22) on their lower sides, and a circulating spray system is provided in the absorption tower; the reaction unit comprises a buffer tank 1 (1) arranged in front of the water scrubbing tower and a buffer tank 2 (2) arranged in front of the alkali scrubbing tower; and further comprises a concentration detection system, including a detection component (3), wherein the detection component (3) is used to detect the pH value in the absorption tower.

2. The high-purity nitrogen monoxide tail gas absorption device according to claim 1, characterized in that: The buffer tank 1 (1) and the buffer tank 2 (2) are provided with an air inlet (11) and an exhaust gas inlet (12), and an air outlet (13) is provided at the top.

3. The high-purity nitrogen monoxide tail gas absorption device according to claim 2, characterized in that: A partition plate (14) is provided inside the buffer tank 1 (1) and the buffer tank 2 (2), and fine holes are provided on the partition plate (14).

4. The high-purity nitrogen monoxide tail gas absorption device according to claim 1, characterized in that: The reaction unit further comprises a plurality of blowers (4), the blowers (4) being connected to the buffer tank 1 (1) and the buffer tank 2 (2) via an air inlet pipe (15), the air inlet pipe (15) extending into the interior of the buffer tank 1 (1) and the buffer tank 2 (2), with the ends being bent downward.

5. The high-purity nitrogen monoxide tail gas absorption device according to claim 2, characterized in that: A one-way valve (16) is provided at the tail gas inlet (12) of the buffer tank 1 (1).

6. The high-purity nitrogen monoxide tail gas absorption device according to claim 1, characterized in that: The water washing tower comprises a water washing tower 1 (5) and a water washing tower 2 (6). The bottom of the water washing tower 1 (5) is provided with an air inlet connected to the buffer tank 1 (1), and the air inlet provided at the bottom of the water washing tower 2 (6) is connected to the outlet provided on the water washing tower 1 (5).

7. The high-purity nitrogen monoxide tail gas absorption device according to claim 1, characterized in that: The circulating spraying system comprises a nozzle (7) arranged at the top of the absorption tower and a holding tank (71) arranged at the bottom of the absorption tower. The holding tank (71) is connected to the nozzle (7) via a connecting pipe (72). A circulating pump (73) is provided on the connecting pipe (72).

8. The high-purity nitrogen monoxide tail gas absorption device according to claim 1, characterized in that: The alkali washing tower comprises an alkali washing tower 1 (8) and an alkali washing tower 2 (9), wherein the alkali washing tower 2 (9) is connected to the alkali washing tower 1 (8), and the alkali washing tower 2 (9) is connected to a chimney (91).

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