Tail gas recovery device and refining system

Abstract

The utility model relates to a tail gas recovery device. The tail gas recovery device comprises an absorption tank, a gas chamber, a collection tank and a spraying mechanism, reaction substances for absorbing corresponding components in the tail gas are arranged in the absorption tank; the gas chamber is connected with the absorption tank and is used for collecting gas discharged from the absorption tank; the collecting tank and the spraying mechanism are both connected with the air chamber; when the pressure in the air chamber is greater than or equal to a first preset pressure, the air chamber is communicated with the collecting tank, and when the pressure in the air chamber is greater than or equal to a second preset pressure, the air chamber is communicated with the spraying mechanism; the second preset pressure is greater than the first preset pressure. The absorption tank is connected with the oxidation furnace, reaction substances in the absorption tank absorb selenium dioxide in tail gas, residual gas enters the gas chamber, when the pressure is larger than or equal to the first preset pressure, the gas in the gas chamber enters the collection tank to be collected, oxygen in the gas can be collected, waste of the oxygen is reduced, and cost is reduced. The utility model further relates to a refining system.

Description

Technical Field

[0001] The present application belongs to the technical field of refining equipment, and specifically relates to a tail gas recovery device and a refining system. Background Art

[0002] Selenium dioxide is a white, shiny crystal that is very volatile. Gaseous selenium dioxide condenses into white or light yellow needles. Selenium dioxide has a wide range of applications, including metallurgy: as an additive in the production of electrolytic manganese; agriculture: as a raw material for foliar fertilizer for selenium-containing crops; aquaculture: used in the production of sodium selenite as a feed additive; chemicals and glass: as a raw material for the production of selenium compounds, which are used as decolorants and colorants for glass, and in the synthesis of various selenates in fine chemicals, as organic synthesis oxidants, catalysts, and electroplating surface treatment agents, etc.

[0003] At present, selenium dioxide is usually prepared by refining crude selenium, and the refining methods of crude selenium include oxygen oxidation, nitric acid oxidation or nitric acid and oxygen co-oxidation. In the method of preparing selenium dioxide by refining crude selenium by nitric acid and oxygen co-oxidation, nitric acid and oxygen need to be continuously introduced into the furnace, resulting in a large amount of nitrogen oxides produced during the production of selenium dioxide. The existing solution is to use a spray tower for tail gas treatment, but this results in a large amount of oxygen consumption and high cost. Utility Model Content

[0004] The technical problem to be solved by the present application is that the existing process of refining selenium dioxide from crude selenium consumes a lot of oxygen and is costly, and a tail gas recovery device and a refining system are provided that can reduce oxygen consumption and lower costs.

[0005] The technical solution proposed in this application is:

[0006] A tail gas recovery device, comprising:

[0007] An absorption tank, which is provided with reaction materials for absorbing corresponding components in the tail gas;

[0008] A gas chamber connected to the absorption tank and used to collect the gas discharged from the absorption tank;

[0009] The collecting tank and the spraying mechanism are both connected to the air chamber;

[0010] When the pressure in the air chamber is greater than or equal to a first preset pressure, the air chamber is connected to the collection tank; when the pressure in the air chamber is greater than or equal to a second preset pressure, the air chamber is connected to the spray mechanism; the first preset pressure is lower than the second preset pressure.

[0011] Further, the exhaust gas recovery device comprises a first pneumatic valve and a second pneumatic valve arranged in the air chamber, the first pneumatic valve is connected to the collection tank, and the second pneumatic valve is connected to the spray mechanism;

[0012] When the pressure in the air chamber is less than the first preset pressure, the first pneumatic valve and the second pneumatic valve are both closed; when the pressure in the air chamber is greater than or equal to the first preset pressure, the first pneumatic valve is opened; when the pressure in the air chamber is greater than or equal to the second preset pressure, the second pneumatic valve is opened.

[0013] Further, the exhaust gas recovery device comprises a first pneumatic valve and a second pneumatic valve arranged in the air chamber, the first pneumatic valve is connected to the spray mechanism, and the second pneumatic valve is connected to the collection tank;

[0014] When the pressure in the air chamber is greater than or equal to the second preset pressure, the first pneumatic valve is opened and the second pneumatic valve is closed; when the pressure in the air chamber is greater than or equal to the first preset pressure and less than the second preset pressure, the first pneumatic valve is closed and the second pneumatic valve is opened; when the pressure in the air chamber is less than the first preset pressure, both the first pneumatic valve and the second pneumatic valve are closed.

[0015] Furthermore, the exhaust gas recovery device further comprises an air pump, and the air pump is connected between the air chamber and the collection tank;

[0016] When the pressure in the air chamber is greater than or equal to a third preset pressure, the vacuum pump is started to draw the gas in the air chamber into the collection tank;

[0017] Wherein, the third preset pressure is lower than the second preset pressure.

[0018] Furthermore, the reaction material is an alkaline solution.

[0019] Furthermore, the tail gas recovery device also includes an air inlet pipe, and the air outlet end of the air inlet pipe is located in the absorption tank and extends into the alkaline solution.

[0020] Furthermore, a desiccant is provided in the collection tank.

[0021] Furthermore, the tail gas recovery device further comprises a third pneumatic valve, the third pneumatic valve is arranged in the collection tank, and the third pneumatic valve can be connected to the oxidation furnace;

[0022] When the pressure in the collection tank is greater than or equal to a fourth preset pressure, the third pneumatic valve is opened; when the pressure in the collection tank is less than the fourth preset pressure, the third pneumatic valve is closed.

[0023] Furthermore, the tail gas recovery device also includes a collection cabinet, which is connected to the oxidation furnace and is used to collect tail gas, and the absorption tank is connected to the collection cabinet.

[0024] A refining system comprises an oxidation furnace and the tail gas recovery device as described above, wherein the absorption tank is connected to the oxidation furnace.

[0025] Furthermore, the refining system also includes an oxidation furnace, and the collecting tank is connected to the oxidation furnace.

[0026] The above-mentioned tail gas recovery device is used to connect the absorption tank to the oxidation furnace. The reaction material in the absorption tank absorbs the selenium dioxide in the tail gas, and the remaining gas enters the gas chamber. When the pressure is greater than or equal to the first preset pressure, the gas in the gas chamber enters the collection tank for collection. In this way, the oxygen in the gas can be collected, reducing the waste of oxygen and reducing costs. At the same time, when the pressure is greater than or equal to the second preset pressure, the gas in the gas chamber can enter the spray mechanism and be discharged after being treated. When the pressure in the gas chamber is too high, the pressure can be relieved to ensure the reliability of the operation of the tail gas recovery device. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are used to provide further understanding of the present application and constitute a part of the specification. They are used to explain the present application together with the embodiments of the present application and do not constitute a limitation of the present application.

[0028] Figure 1 A schematic diagram of the principle of a refining system provided in one embodiment of the present application;

[0029] Figure 2 for Figure 1 The connection diagram of some structures in the refining system is shown.

[0030] Description of labels:

[0031] 100. Refining system; 110. Oxidation furnace; 120. Absorption tank; 130. Gas chamber; 140. Collecting tank; 150. Spraying mechanism; 160. Collecting cabinet; 170. Air inlet pipe; 121. Feeding port; 181. First pneumatic valve; 182. Second pneumatic valve; 190. Third pneumatic valve. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0033] In the description of the present 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 indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0034] like Figure 1 and Figure 2 As shown, an embodiment of the present application provides a refining system 100, including an oxidation furnace 110 and a tail gas recovery device, wherein the tail gas recovery device is connected to the oxidation furnace 110, and is used to receive the tail gas generated by the oxidation furnace 110 and process and recover it.

[0035] In one embodiment, the tail gas recovery device includes an absorption tank 120, a gas chamber 130, a collection tank 140 and a spray mechanism 150. The absorption tank 120 is provided with a reaction material for absorbing the corresponding components in the tail gas, the gas chamber 130 is connected to the absorption tank 120, and is used to collect the gas discharged from the absorption tank 120, and the collection tank 140 and the spray mechanism 150 are both connected to the gas chamber 130.

[0036] When the pressure in the air chamber 130 is greater than or equal to the first preset pressure, the air chamber 130 is communicated with the collection tank 140 so that the gas in the air chamber 130 enters the collection tank 140; when the pressure in the air chamber 130 is greater than or equal to the second preset pressure, the air chamber 130 is communicated with the spray mechanism 150 so that the gas in the air chamber 130 enters the spray mechanism 150. The first preset pressure is less than the second preset pressure.

[0037] It should be noted that, in this embodiment, the refining system 100 is used to refine crude selenium to prepare selenium dioxide, and the reaction substance in the corresponding absorption tank 120 is a sodium hydroxide solution, and the pH value of the sodium hydroxide solution is 9-12. After the tail gas passes into the absorption tank 120, it reacts with the sodium hydroxide solution. The main reaction formula is as follows:

[0038] SeO 2 +2OH - →SeO 3 2- +H 2 O

[0039] It can be seen that the sodium hydroxide solution in the absorption tank 120 can absorb the selenium dioxide in the tail gas, thereby preventing a large amount of selenium dioxide from entering the spray mechanism 150, preventing a large amount of selenium dioxide from polluting the pipes and pools in the spray mechanism 150, and there is no need to frequently clean the spray mechanism 150. At the same time, the sodium hydroxide solution can also absorb nitrogen oxides in the tail gas. Of course, in other embodiments, the reaction material can also be other alkaline solutions that can react with selenium dioxide and absorb nitrogen oxides.

[0040] The above-mentioned tail gas recovery device is used to connect the absorption tank 120 with the oxidation furnace 110. The reaction material in the absorption tank 120 absorbs the selenium dioxide in the tail gas, and the remaining gas enters the gas chamber 130. When the pressure is greater than or equal to the first preset pressure, the gas in the gas chamber 130 enters the collection tank 140 for collection. In this way, the oxygen in the gas can be collected, reducing the waste of oxygen and reducing costs. At the same time, when the pressure is greater than or equal to the second preset pressure, the gas in the gas chamber 130 can enter the spray mechanism 150 and be discharged after being treated. When the pressure in the gas chamber 130 is too high, the pressure can be relieved to ensure the reliability of the operation of the tail gas recovery device.

[0041] Furthermore, the collecting tank 140 is also connected to the oxidation furnace 110 to input the collected gas into the oxidation furnace 110, and reuse the oxygen in the recovered gas, thereby reducing oxygen consumption, reducing oxygen waste, and reducing costs.

[0042] In one embodiment, the tail gas recovery device further includes a collection cabinet 160, which is connected to the oxidation furnace 110 and is used to collect the tail gas generated by the oxidation furnace 110, and the absorption tank 120 is connected to the collection cabinet 160 and is used to receive the tail gas collected by the collection cabinet 160. It can be understood that the tail gas directly discharged from the oxidation furnace 110 has a high temperature, and the temperature of the tail gas drops after passing through the collection cabinet 160, and then enters the absorption tank 120 for absorption.

[0043] In one embodiment, the exhaust gas recovery device further includes an air inlet pipe 170, the air inlet end of the air inlet pipe 170 is connected to the collection cabinet 160, and the air outlet end is located in the absorption tank 120 and extends into the sodium hydroxide solution to ensure that the selenium dioxide in the exhaust gas reacts with the sodium hydroxide solution. Optionally, the air inlet pipe 170 is a plastic hose to facilitate installation while preventing the air inlet pipe 170 from reacting with the sodium hydroxide solution or the exhaust gas.

[0044] In one embodiment, the absorption tank 120 includes a feeding port 121 connected to the inside thereof, and the feeding port 121 can be used to add sodium hydroxide solution (or water and sodium hydroxide). Further, a sealing cover is provided at the feeding port 121, and the sealing cover is used to open or close the feeding port 121.

[0045] In one embodiment, the exhaust gas recovery device further includes a first pneumatic valve 181 and a second pneumatic valve 182 , both of which are disposed in the air chamber 130 , and the first pneumatic valve 181 is connected to the collection tank 140 , and the second pneumatic valve 182 is connected to the spray mechanism 150 .

[0046] When the pressure in the air chamber 130 is greater than or equal to the first preset pressure, the first pneumatic valve 181 is opened, so that the air chamber 130 is connected with the collecting tank 140, and the gas in the air chamber 130 enters the collecting tank 140, and then enters the oxidation furnace 110 through the collecting tank 140 to reuse the oxygen in the exhaust gas; when the pressure in the air chamber 130 is greater than or equal to the second preset pressure, the second pneumatic valve 182 is opened, so that the air chamber 130 can be connected with the spray mechanism 150, and the gas in the air chamber 130 enters the spray mechanism 150, and is discharged after being processed by the spray mechanism 150; when the pressure in the air chamber 130 is less than the first preset pressure, the first pneumatic valve 181 and the second pneumatic valve 182 are both closed, that is, the gas in the air chamber 130 enters the collecting tank 140 after reaching a certain amount, and is then transported back to the oxidation furnace 110.

[0047] In one embodiment, the exhaust gas recovery device further includes an air pump connected between the air chamber 130 and the collection tank 140. When the pressure in the air chamber 130 is greater than or equal to the third preset pressure, the air pump is started to pump the gas in the air chamber 130 into the collection tank 140; when the pressure in the air chamber 130 is less than the third preset pressure, the air pump is turned off.

[0048] Among them, the third preset pressure is less than the second preset pressure. It should be explained that the third preset pressure is close to the value of the first preset pressure, so as to ensure that when the pressure of the air chamber 130 meets the requirement for the second pneumatic valve 182 to be opened, the vacuum pump can be started to pump the gas in the air chamber 130 into the collection tank 140, so it is preferred that the third preset pressure is greater than the first preset pressure. At the same time, the setting of the third preset pressure is related to the gas flow rate of the absorption tank 120 input into the air chamber 130, which is used to prevent the gas in the collection tank 140 from flowing back into the air chamber 130 after the vacuum pump is turned off.

[0049] In one embodiment, a desiccant is provided in the collection tank 140 to dry the gas entering the collection tank 140 to remove water vapor in the gas, and then the dry oxygen is transported to the oxidation furnace 110 for reuse.

[0050] In one embodiment, the tail gas recovery device further includes a third pneumatic valve 190 , which is disposed in the collection tank 140 and connected to the oxidation furnace 110 .

[0051] When the pressure in the collection tank 140 is greater than or equal to the fourth preset pressure, the third pneumatic valve 190 opens to input oxygen into the oxidation furnace 110; when the pressure in the collection tank 140 is less than the fourth preset pressure, the third pneumatic valve 190 closes.

[0052] It should be explained that the fourth preset pressure is determined based on the conditions in the air chamber 130 and the oxidation furnace 110. For the air chamber 130, when the first pneumatic valve 181 is opened, the pressure in the collection tank 140 cannot exceed the pressure in the air chamber 130 too much to avoid the gas in the collection tank 140 from flowing back into the air chamber 130; for the oxidation furnace 110, it is necessary to ensure that the pressure in the collection tank 140 is sufficient to input the gas into the oxidation furnace 110.

[0053] In order to facilitate understanding of the technical solution of this application, Figure 1 and Figure 2 The process flow of the refining system 100 in the above embodiment is described as follows:

[0054] The crude selenium is oxidized and refined in the oxidation furnace 110, and nitric acid and oxygen are continuously introduced into the oxidation furnace 110 during the refining process. The tail gas generated by the oxidation furnace 110 enters the collection cabinet 160, and after being cooled to a certain extent, enters the absorption tank 120 through the air inlet pipe 170. The selenium dioxide in the tail gas reacts with the sodium hydroxide solution in the absorption tank 120, and the nitrogen oxides in the tail gas are also absorbed by the sodium hydroxide solution. The gas treated by the absorption tank 120 enters the gas chamber 130.

[0055] When the pressure in the air chamber 130 is greater than or equal to the first preset pressure, the first pneumatic valve 181 is opened, and at the same time, when the pressure in the air chamber 130 is greater than or equal to the third preset pressure, the vacuum pump is started, and the vacuum pump pumps the gas in the air chamber 130 into the collection tank 140. The desiccant in the collection tank 140 dries the gas, and when the pressure in the collection tank 140 is greater than or equal to the fourth preset pressure, the third pneumatic valve 190 is opened, and the gas in the collection tank 140 is input into the oxidation furnace 110 to realize the reuse of oxygen.

[0056] If a large amount of exhaust gas is generated in the oxidation furnace 110, so that the pressure in the air chamber 130 is greater than or equal to the second preset pressure, at this time, the second pneumatic valve 182 is opened, and the gas in the air chamber 130 can be input into the spray mechanism 150 for treatment and then discharged, thereby avoiding excessive pressure in the air chamber 130.

[0057] It should be noted that the spray mechanism 150 is a conventional mechanism and will not be described in detail here.

[0058] Since the collecting cabinet 160, the absorption tank 120 and the air chamber 130 are provided between the oxidation furnace 110 and the spray mechanism 150, the oxidation furnace 110 is prevented from being directly connected to the spray mechanism 150 in a negative pressure state, thereby preventing the negative pressure in the spray mechanism 150 from affecting the pressure in the oxidation furnace 110, and slowing down the rate of oxygen discharge in the oxidation furnace 110, thereby extending the reaction time of crude selenium and oxygen and improving the refining effect.

[0059] In addition, it should be further explained that in order to prevent excessive pressure in the air chamber 130 from affecting the exhaust fan and the collection tank 140, the first pneumatic valve 181 can be closed when the pressure in the air chamber 130 is greater than or equal to the second preset pressure.

[0060] Although the embodiments of the present application have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A tail gas recovery device, characterized in that: include: An absorption tank, which is provided with reaction materials for absorbing corresponding components in the tail gas; A gas chamber connected to the absorption tank and used to collect the gas discharged from the absorption tank; The collecting tank and the spraying mechanism are both connected to the air chamber; When the pressure in the air chamber is greater than or equal to a first preset pressure, the air chamber is connected to the collection tank; when the pressure in the air chamber is greater than or equal to a second preset pressure, the air chamber is connected to the spray mechanism; the first preset pressure is lower than the second preset pressure.

2. The tail gas recovery device according to claim 1, characterized in that: The tail gas recovery device comprises a first pneumatic valve and a second pneumatic valve arranged in the air chamber, the first pneumatic valve is connected to the collection tank, and the second pneumatic valve is connected to the spray mechanism; When the pressure in the air chamber is less than the first preset pressure, the first pneumatic valve and the second pneumatic valve are both closed; when the pressure in the air chamber is greater than or equal to the first preset pressure, the first pneumatic valve is opened; when the pressure in the air chamber is greater than or equal to the second preset pressure, the second pneumatic valve is opened.

3. The tail gas recovery device according to claim 1, characterized in that: The tail gas recovery device further comprises an air pump connected between the air chamber and the collection tank; When the pressure in the air chamber is greater than or equal to a third preset pressure, the vacuum pump is started to draw the gas in the air chamber into the collection tank; Wherein, the third preset pressure is lower than the second preset pressure.

4. The tail gas recovery device according to claim 1, characterized in that: The reaction material is an alkaline solution.

5. The tail gas recovery device according to claim 4, characterized in that: The tail gas recovery device also includes an air inlet pipe, and the air outlet end of the air inlet pipe is located in the absorption tank and extends into the alkaline solution.

6. The tail gas recovery device according to claim 1, characterized in that: A desiccant is arranged in the collecting tank.

7. The tail gas recovery device according to claim 1, characterized in that: The tail gas recovery device further comprises a third pneumatic valve, which is arranged in the collection tank and can be connected to the oxidation furnace; When the pressure in the collection tank is greater than or equal to a fourth preset pressure, the third pneumatic valve is opened; when the pressure in the collection tank is less than the fourth preset pressure, the third pneumatic valve is closed.

8. The tail gas recovery device according to claim 1, characterized in that: The tail gas recovery device also includes a collection cabinet, which is connected to the oxidation furnace and is used to collect tail gas, and the absorption tank is connected to the collection cabinet.

9. A refining system, characterized in that: It comprises an oxidation furnace and a tail gas recovery device as described in any one of claims 1 to 8, wherein the absorption tank is connected to the oxidation furnace.

10. The refining system according to claim 9, characterized in that The refining system further comprises an oxidation furnace, and the collecting tank is connected to the oxidation furnace.

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