Tail gas treatment device and processing system

Abstract

The tail gas treatment device comprises a first gas inlet pipe, a second gas inlet pipe, a buffer tank, a first spray tower, a second spray tower and a third spray tower. The first air inlet pipe and the second air inlet pipe are connected with the buffer tank; the first spray tower is arranged at the downstream of the buffer tank and is connected with the buffer tank; the second spray tower is arranged at the downstream of the first spray tower and is connected with the first spray tower; the third spray tower is arranged at the downstream of the second spray tower and is connected with the second spray tower; spraying liquid in the first spraying tower is water, and spraying liquid in the second spraying tower and the third spraying tower is alkali liquor. The tail gas containing nitrogen oxide is firstly oxidized in the buffer tank and then sequentially subjected to primary water spraying and two-stage alkali liquid spraying, so that the conversion rate of the nitrogen oxide in the tail gas can be effectively improved, NO in the discharged tail gas is removed, and the discharged gas is ensured to be qualified. Meanwhile, compared with catalyst reduction, the cost is lower. The utility model further discloses a machining system.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of waste gas treatment, and particularly relates to a tail gas treatment device and a processing system. BACKGROUND

[0002] At present, in the processes of catalyst manufacturing, noble metal hydrometallurgy, metal surface treatment, semiconductor material cleaning and the like, tail gas containing nitrogen oxides is generated. The existing treatment method for the tail gas containing nitrogen oxides is usually catalytic reduction, that is, a catalyst is used to promote chemical reaction of nitrogen oxides and a reducing agent to convert the nitrogen oxides into nitrogen and water. Although this method has a high conversion rate, it has a high cost, and the catalyst has a risk of deactivation affecting the conversion rate. CONTENT OF THE UTILITY MODEL

[0003] The technical problem to be solved by the application is that the existing catalytic reduction method for treating the tail gas containing nitrogen oxides has a high cost, and the catalyst has a risk of deactivation. In order to solve the above technical problem, the application provides a tail gas treatment device and a processing system, which have a high conversion rate of nitrogen oxides and a low treatment cost.

[0004] The technical scheme provided by the application is as follows:

[0005] A tail gas treatment device comprises:

[0006] a buffer tank;

[0007] a first gas inlet pipe and a second gas inlet pipe, both of which are connected with the buffer tank;

[0008] a first spray tower arranged downstream of the buffer tank and connected with the buffer tank;

[0009] a second spray tower arranged downstream of the first spray tower and connected with the first spray tower;

[0010] a third spray tower arranged downstream of the second spray tower and connected with the second spray tower;

[0011] wherein the spray liquid in the first spray tower is water, and the spray liquid in the second spray tower and the third spray tower is alkali solution.

[0012] Further, the tail gas treatment device further comprises a third gas inlet pipe connected with the third spray tower.

[0013] Further, the third gas inlet pipe is connected with the lower side of the third spray tower.

[0014] Further, the tail gas treatment device further comprises a first fan arranged in the first gas inlet pipe and a second fan arranged in the second gas inlet pipe.

[0015] Further, the first fan is a high-pressure induced draft fan, and the second fan is a Roots blower.

[0016] Further, the tail gas treatment device further comprises a first connecting pipe, a second connecting pipe and a third connecting pipe.

[0017] One end of the first connecting pipe is connected to the top of the buffer tank, and the other end is connected to the lower side of the first spray tower; one end of the second connecting pipe is connected to the top of the first spray tower, and the other end is connected to the lower side of the second spray tower; one end of the third connecting pipe is connected to the top of the second spray tower, and the other end is connected to the lower side of the third spray tower.

[0018] Further, the tail gas treatment device further comprises an air induction assembly connected to the third spray tower.

[0019] Further, the air induction assembly comprises an air induction pipe, an air induction fan and an exhaust pipe, one end of the air induction pipe is connected to the top of the third spray tower, and the other end is connected to the air induction fan, and the exhaust pipe is connected to the outlet end of the air induction fan.

[0020] Further, the tail gas treatment device further comprises a first liquid discharge pipe and a first liquid discharge valve, the first liquid discharge pipe is connected to the bottom of the buffer tank, and the first liquid discharge valve is arranged on the first liquid discharge pipe.

[0021] A processing system comprising the tail gas treatment device as described above.

[0022] By using the tail gas treatment device described above, the tail gas containing nitrogen oxides is first oxidized in the buffer tank, and then sequentially passes through one-stage water spraying and two-stage alkali liquid spraying, which can effectively improve the conversion rate of nitrogen oxides in the tail gas, remove NO in the exhaust gas, and ensure that the exhaust gas is qualified. At the same time, water spraying is used in the first stage, and two-stage alkali liquid spraying is used, which is lower in cost than catalyst reduction.

[0023] In addition, it can be understood that in the first spray tower using water spraying, water reacts with NO2 to generate nitric acid, which can be recycled and reused, thereby further saving raw material costs. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate the present application together with the embodiments thereof, and explain the present application, but do not limit the present application.

[0025] Figure 1 The structure schematic diagram of the tail gas treatment device provided by an embodiment of the present application.

[0026] REFERENCE NUMERALS

[0027] 100. Exhaust gas treatment device; 111. First air inlet pipe; 112. Second air inlet pipe; 120. Buffer tank; 130. First spray tower; 140. Second spray tower; 150. Third spray tower; 113. First fan; 114. Second fan; 121. First drain pipe; 122. First drain valve; 161. First connecting pipe; 162. Second connecting pipe; 163. Third connecting pipe; 115. Third air inlet pipe; 170. Induced draft assembly; 171. Induced draft pipe; 172. Induced draft fan; 173. Exhaust pipe; 174. Second drain pipe; 175. Second drain valve. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0029] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0030] The present application provides a processing system that can be used for the processing and preparation of products. During the processing and preparation process, the processing system generates tail gas containing nitrogen oxides. Therefore, the processing system is also provided with a tail gas treatment device for treating the tail gas containing nitrogen oxides. At the same time, the tail gas treatment device has the advantages of high nitrogen oxide conversion rate and low treatment cost when treating tail gas containing nitrogen oxides. Optionally, the applications of the processing system include, but are not limited to, processes such as catalyst manufacturing, precious metal hydrometallurgy, metal surface treatment, semiconductor material cleaning, nitration reaction, and oxalic acid manufacturing.

[0031] like Figure 1 As shown, the exhaust gas treatment device 100 includes a first air inlet pipe 111 , a second air inlet pipe 112 , a buffer tank 120 , a first spray tower 130 , a second spray tower 140 and a third spray tower 150 .

[0032] The first gas inlet pipe 111 and the second gas inlet pipe 112 are connected with the buffer tank 120, the first gas inlet pipe 111 is used for inputting the tail gas containing nitrogen oxides into the buffer tank 120, and the nitrogen oxides are NO in the embodiment; the second gas inlet pipe 112 is used for inputting air or oxygen into the buffer tank 120 to oxidize the NO to form NO2. It needs to be explained that in the embodiment, the amount of gas input by the second gas inlet pipe 112 is determined according to the amount of gas input by the first gas inlet pipe 111, so as to ensure that all the NO entering the buffer tank 120 is oxidized into NO2.

[0033] The first spray tower 130, the second spray tower 140 and the third spray tower 150 are sequentially arranged downstream of the buffer tank 120, and the first spray tower 130 is connected with the buffer tank 120, the second spray tower 140 is connected with the first spray tower 130, and the third spray tower 150 is connected with the second spray tower 140, so as to sequentially spray and treat the tail gas.

[0034] Among them, the spraying liquid in the first spray tower 130 is water, and the spraying liquid in the second spray tower 140 and the third spray tower 150 is alkali solution.

[0035] It needs to be explained that in the first spray tower 130, water reacts with NO2 to produce nitric acid and NO, and the generated NO is oxidized into NO2 again. The specific reaction equation is: 3NO2+H2O=2HNO3+NO, 2NO+O2=2NO2. Therefore, in the first spray tower 130, a large amount of nitrogen oxides is converted into nitric acid for collection, but part of the nitrogen oxides in the tail gas is transported to the downstream second spray tower 140 and the third spray tower 150. In the second spray tower 140 and the third spray tower 150, alkali solution, such as sodium hydroxide solution or other alkaline solution capable of reacting with nitrogen oxides, is sprayed. Taking the sodium hydroxide solution as an example, it can react with nitrogen oxides to generate nitrate, and the specific reaction equation is: NO+NO2+2NaOH=2NaNO2+H2O, 2NaOH+2NO2=2NaNO3+H2O. At the same time, the setting of the two-stage alkali spray tower can effectively improve the conversion rate of nitrogen oxides, so that the nitrogen oxides in the tail gas can be effectively removed to ensure that the exhaust gas is qualified.

[0036] It needs to be further explained that the collection of nitric acid in the first spray tower 130 can be collected by setting a collection tank, that is, a collection tank is arranged at the bottom of the spray tower. Of course, other collection methods can also be used, which are not limited herein.

[0037] With the tail gas treatment device 100, the tail gas containing nitrogen oxides is first oxidized in the buffer tank 120, and then sequentially passes through the first water spray and the two-stage alkali liquor spray, which can effectively improve the conversion rate of nitrogen oxides in the tail gas, remove NO in the exhaust gas, and ensure that the exhaust gas is qualified. At the same time, the first stage uses water spray, and the two stages use alkali liquor spray, which is lower in cost than catalyst reduction.

[0038] In addition, it can be understood that in the first spray tower 130 using water spray, water reacts with NO2 to generate nitric acid, which can be recycled and reused, thereby further saving raw material costs.

[0039] In one embodiment, the tail gas treatment device 100 further comprises a first fan 113 and a second fan 114. The first fan 113 is arranged on the first gas inlet pipe 111 and used to guide the tail gas into the buffer tank 120. The second fan 114 is arranged on the second gas inlet pipe 112 and used to guide air or oxygen into the buffer tank 120. Preferably, the first fan 113 is a high-pressure induced draft fan 172, and the second fan 114 is a Roots blower, so as to ensure that the air or oxygen entering through the second gas inlet pipe 112 can oxidize all the nitrogen oxides in the tail gas.

[0040] In one embodiment, the tail gas treatment device 100 further comprises a first liquid discharge pipe 121 and a first liquid discharge valve 122. The first liquid discharge pipe 121 is connected to the bottom of the buffer tank 120, and the first liquid discharge valve 122 is arranged on the first liquid discharge pipe 121. The two are used in cooperation to discharge the condensed liquid in the buffer tank 120. It can be understood that after the tail gas and air enter the buffer tank 120, the temperature will change, and the liquid carried in the gas will condense. In order to avoid the accumulation of condensed liquid in the buffer tank 120, the first liquid discharge pipe 121 is arranged. At the same time, in order to avoid the gas from being discharged from the first liquid discharge pipe 121, the first liquid discharge valve 122 is arranged on the first liquid discharge pipe 121.

[0041] In one embodiment, the tail gas treatment device 100 further comprises a first connecting pipe 161, a second connecting pipe 162, and a third connecting pipe 163. One end of the first connecting pipe 161 is connected to the top of the buffer tank 120, and the other end is connected to the lower side of the first spray tower 130. One end of the second connecting pipe 162 is connected to the top of the first spray tower 130, and the other end is connected to the lower side of the second spray tower 140. One end of the third connecting pipe 163 is connected to the top of the second spray tower 140, and the other end is connected to the lower side of the third spray tower 150. In this way, the conveying direction of the tail gas in each spray tower and the spraying direction of the spray liquid are opposite, so that the tail gas and the spray liquid are opposite, the contact probability of the tail gas and the spray liquid is improved, and the conversion rate of nitrogen oxides in the tail gas is improved.

[0042] In one embodiment, the tail gas treatment device 100 further comprises a third air inlet pipe 115 connected to the third spray tower 150 for inputting air or oxygen into the third spray tower 150. It is to be noted that, as mentioned above, some of the tail gas will still remain after passing through the first spray tower 130 and the second spray tower 140, and in order to ensure that all of the NO in the nitrogen oxides is oxidized and removed, the third air inlet pipe 115 is connected to the lower side of the third spray tower 150.

[0043] Specifically, after the NO2 enters the second spray tower 140 and the third spray tower 150, part of the NO2 will react with water to generate NO and nitric acid (as mentioned above, the reaction equation is as follows), and the nitric acid will react with the lye solution to generate nitrate and water, and the reaction equation is as follows: HNO3+ NaOH = NaNO3+ H2O. By inputting air or oxygen into the third spray tower 150, the NO generated by the reaction of NO2 and water will also be quickly oxidized into NO2, thereby avoiding the residual NO in the discharged gas.

[0044] In one embodiment, the tail gas treatment device 100 further comprises an air induction assembly 170 connected to the third spray tower 150 for guiding the gas in the third spray tower 150 after the spray treatment to be discharged. It can be understood that the gas in the third spray tower 150 is guided out through the air induction assembly 170, so the air induction assembly 170 does not need to be provided with a fan to guide the gas into the third spray tower 150. Similarly, in the case of using the air induction assembly 170, the first fan 113 on the first air inlet pipe 111 can also not be provided, and the tail gas is guided into the buffer tank 120 through the air induction assembly 170 and sequentially passes through the first spray tower 130, the second spray tower 140 and the third spray tower 150. Of course, in the case of not providing the first fan 113, it is still preferred to provide the second fan 114 to control the amount of air or oxygen input into the buffer tank 120.

[0045] Further, the air induction assembly 170 comprises an air induction pipe 171, an air induction fan 172 and an exhaust pipe 173. One end of the air induction pipe 171 is connected to the top of the third spray tower 150, the other end is connected to the inlet end of the air induction fan 172, and the exhaust pipe 173 is connected to the outlet end of the air induction fan 172, so that the tail gas in the third spray tower 150 is guided to sequentially pass through the air induction pipe 171 and the exhaust pipe 173 and be discharged through the air induction fan 172.

[0046] In one embodiment, the air induction assembly 170 further comprises a second liquid discharge pipe 174 and a second liquid discharge valve 175, the second liquid discharge pipe 174 is connected to the air induction pipe 171, and the second liquid discharge valve 175 is arranged on the second liquid discharge pipe 174, which are used in cooperation to discharge the condensed liquid in the air induction pipe 171.

[0047] It is to be noted that, Figure 1The structure shown is used for facilitating understanding of the connection relationship between the air duct 171 and the third spray tower 150 and the induced draft fan 172 and the connection relationship between the second liquid discharge pipe 174 and the air duct 171, and does not limit the structure of the air duct 171. In actual application, a U-shaped section can be arranged on the air duct 171, and the bottom of the U-shaped section is used for depositing condensed liquid to avoid liquid flowing into the induced draft fan 172. The second liquid discharge pipe 174 is connected with the bottom of the U-shaped section and is used for discharging condensed liquid to avoid liquid accumulation affecting gas conveying.

[0048] In order to facilitate understanding of the technical solutions of the present application, hereinafter the technical solutions of the present application will be described in detail in combination with Figure 1 The processing flow of the tail gas treatment device 100 in the above embodiment will be described:

[0049] The first fan 113 guides the tail gas containing nitrogen oxides into the buffer tank 120, and at the same time, the second fan 114 also guides air into the buffer tank 120 according to the flow of the tail gas, and all the NO in the tail gas is oxidized into NO2. Subsequently, the gas successively passes through the first spray tower 130, and water and NO2 react to generate nitric acid and NO, the nitric acid is recovered, and the remaining NO2 and NO continue to flow through the second spray tower 140 and the third spray tower 150. In the second spray tower 140 and the third spray tower 150, most of the NO2 and most of the NO directly react with lye to generate nitrate / nitrite, part of the NO2 and water react to generate nitric acid and NO, and in the third spray tower 150, the NO is oxidized into NO2 again. The gas treated in the third spray tower 150 successively passes through the air duct 171 and the exhaust pipe 173 and is discharged.

[0050] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. An exhaust gas treatment device, characterized in that: include: Buffer tank; A first air inlet pipe and a second air inlet pipe are both connected to the buffer tank; a first spray tower, disposed downstream of the buffer tank and connected to the buffer tank; a second spray tower, disposed downstream of the first spray tower and connected to the first spray tower; a third spray tower, disposed downstream of the second spray tower and connected to the second spray tower; The spraying liquid in the first spray tower is water, and the spraying liquids in the second spray tower and the third spray tower are both alkaline solutions.

2. The exhaust gas treatment device according to claim 1, characterized in that: The tail gas treatment device further includes a third air inlet pipe, and the third air inlet pipe is connected to the third spray tower.

3. The exhaust gas treatment device according to claim 2, characterized in that: The third air inlet pipe is connected to the lower side of the third spray tower.

4. The exhaust gas treatment device according to claim 1, characterized in that: The exhaust gas treatment device further includes a first fan and a second fan, wherein the first fan is arranged in the first air intake pipe, and the second fan is arranged in the second air intake pipe.

5. The exhaust gas treatment device according to claim 4, characterized in that: The first fan is a high-pressure induced draft fan, and the second fan is a Roots blower.

6. The exhaust gas treatment device according to claim 1, characterized in that: The exhaust gas treatment device further includes a first connecting pipe, a second connecting pipe and a third connecting pipe; One end of the first connecting pipe is connected to the top of the buffer tank, and the other end is connected to the lower side of the first spray tower; One end of the second connecting pipe is connected to the top of the first spray tower, and the other end is connected to the lower side of the second spray tower; One end of the third connecting pipe is connected to the top of the second spray tower, and the other end is connected to the lower side of the third spray tower.

7. The exhaust gas treatment device according to claim 1, characterized in that: The tail gas treatment device further includes an induced draft component, which is connected to the third spray tower.

8. The exhaust gas treatment device according to claim 7, characterized in that: The induced draft component includes an induced draft pipe, an induced draft fan and an exhaust pipe. One end of the induced draft pipe is connected to the top of the third spray tower, and the other end is connected to the induced draft fan. The exhaust pipe is connected to the outlet end of the induced draft fan.

9. The exhaust gas treatment device according to claim 1, characterized in that: The exhaust gas treatment device further includes a first drain pipe and a first drain valve. The first drain pipe is connected to the bottom of the buffer tank, and the first drain valve is arranged on the first drain pipe.

10. A processing system, characterized in that: The exhaust gas treatment device comprises the exhaust gas treatment device according to any one of claims 1 to 9.

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