Bromine extraction system

Abstract

The utility model provides a bromine extraction system. The bromine extraction system comprises a distillation still, a condenser and a separator, the distillation still is provided with a heat exchanger and can contain and heat bromine-containing liquid to form bromine steam. The distillation kettle is connected with the condenser, and bromine steam can be liquefied in the condenser to form bromine. And the condenser is connected with the separator so as to introduce bromine into the separator. A bromine outlet and a bromine water outlet are formed in the separator, and the bromine water outlet is directly or indirectly connected to the distillation kettle, so that the bromine water formed in the separator is introduced into the distillation kettle for cyclic utilization.

Description

Technical Field

[0001] The present application relates to the technical field of bromine-containing wastewater treatment, and in particular to a bromine extraction system. Background Art

[0002] Bromine (liquid bromine and pure bromine) is an important chemical raw material used in the production of a variety of inorganic bromides, bromates, and bromine-containing organic compounds. Therefore, bromine holds special value in economic and technological development. In particular, bromine is crucial in the production of flame retardants, fire extinguishing agents, refrigerants, and photographic materials. It is also widely used in the pharmaceutical, pesticide, and oil and gas industries.

[0003] At present, the extraction technology of bromine generally uses brine as raw material, and the production method mainly adopts steam distillation and air blowing. The use of the above methods to extract bromine will produce a large amount of bromine-containing wastewater during the production process. These bromine-containing wastewaters have the characteristics of low bromine content, large discharge volume, and many impurities in the water. With the increasingly stringent discharge standards and safety requirements for industrial wastewater in the industry, it is urgent to optimize the treatment technology of bromine-containing wastewater. However, the current technology for extracting bromine from bromine-containing industrial wastewater has defects in automation, refinement and standardization, which will result in the extracted bromine of low purity and poor quality, making it difficult to meet the use requirements. At the same time, due to the low degree of automation of the existing production process for extracting bromine from bromine-containing industrial wastewater, manual operations are still required at multiple stages, which also brings production safety risks. Utility Model Content

[0004] This application is made in view of the state of the prior art described above. The purpose of this application is to provide a bromine extraction system capable of extracting bromine from bromine-containing wastewater. Furthermore, the bromine extraction system can reuse the bromine-containing wastewater generated during its production process to improve wastewater utilization.

[0005] The present application provides a bromine extraction system, which includes a distillation kettle, a condenser and a separator.

[0006] The still has a heat exchanger, and the still is capable of receiving and heating the bromine-containing liquid to form bromine vapor.

[0007] The distillation kettle is connected to the condenser, and bromine vapor can be liquefied in the condenser to form bromine.

[0008] The condenser is connected to the separator to pass bromine into the separator,

[0009] The separator is formed with a bromine outlet and a bromine water outlet, and the bromine water outlet is directly or indirectly connected to the distillation kettle so as to pass the bromine water formed in the separator into the distillation kettle for recycling.

[0010] In at least one possible embodiment, the bromine extraction system further includes a bromine storage tank and a bromine water storage tank.

[0011] The bromine storage tank is connected to the bromine outlet of the separator and is used to accommodate bromine.

[0012] The bromine water storage tank is connected to the bromine water outlet of the separator and is used to contain bromine water.

[0013] The bromine water storage tank is also connected to the distillation kettle for passing the bromine water stored in the bromine water storage tank into the distillation kettle for recycling.

[0014] In at least one possible embodiment, the bromine extraction system further comprises a waste gas tower,

[0015] One or more of the distillation kettle, the condenser, the separator, the bromine storage tank, and the bromine water storage tank are connected to the exhaust gas tower via an exhaust gas treatment pipeline to treat the exhaust gas.

[0016] The exhaust gas tower can contain alkaline solution for treating the exhaust gas.

[0017] In at least one possible embodiment, the bromine outlet is formed at the bottom of the separator.

[0018] The bromine water outlet is formed in the middle of the separator.

[0019] In at least one possible embodiment, the bromine extraction system further includes a sulfuric acid feed section and a sodium chlorate feed section.

[0020] The sulfuric acid feed part and the sodium chlorate feed part are connected to the distillation kettle and are used to add concentrated sulfuric acid and sodium chlorate into the distillation kettle respectively.

[0021] In at least one possible embodiment, the bromine extraction system further includes a sodium thiosulfate feeding section.

[0022] The sodium thiosulfate feeding part is connected to the distillation kettle and is used to add sodium thiosulfate into the distillation kettle.

[0023] In at least one possible embodiment, the bromine extraction system further includes a mother liquor tank capable of storing bromine-containing wastewater, and the mother liquor tank is connected to the distillation kettle for adding bromine-containing wastewater into the distillation kettle.

[0024] In at least one possible embodiment, the bromine extraction system further includes a distributed control system comprising a processor and sensors and / or metering instruments.

[0025] In at least one possible embodiment, the separator is provided with a weighing module, which is capable of weighing the liquid in the separator and feeding back the weight information to the processor of the distributed control system for controlling the operation of the bromine extraction system.

[0026] In at least one possible embodiment, the condenser is a shell and tube condenser.

[0027] The bromine extraction system provided in the present application can be used to extract bromine from bromine-containing wastewater. The bromine extraction system can recycle the bromine-containing wastewater generated during the bromine extraction process, thereby improving the utilization rate and production efficiency of the bromine-containing wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The figure is a schematic structural diagram of a bromine extraction system according to one embodiment of the present application.

[0029] Description of Reference Numerals

[0030] 10 Distillation kettle

[0031] 20 Condenser

[0032] 30 separator

[0033] 41 Sulfuric acid feeding section

[0034] 42 Sodium thiosulfate feeding section

[0035] 43 Sodium chlorate feeding section

[0036] 51 Bromine Storage Tank

[0037] 52 Bromine water storage tank

[0038] 60 mother liquor tank DETAILED DESCRIPTION

[0039] The following describes exemplary embodiments of the present application with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, and are not intended to exhaust all possible embodiments of the present application, nor to limit the scope of the present application.

[0040] The embodiment of the present application provides a bromine extraction system for extracting bromine from bromine-containing industrial wastewater. Figure 1 As shown, the bromine extraction system may include a distillation kettle 10, a condenser 20, and a separator 30. The distillation kettle 10, the condenser 20, and the separator 30 may be connected in sequence.

[0041] Specifically, the upper portion of the still kettle 10 can form a feed port and a discharge port. The feed port of the still kettle 10 can be used to pass a bromine-containing liquid. It is understood that the source of the bromine-containing liquid is not limited. In particular, the bromine-containing liquid can be a bromine-containing wastewater, which can include bromine water produced by the bromine extraction system in its previous production cycle and bromine-containing wastewater produced by other sections. The discharge port of the still kettle 10 can be used to pass the bromine vapor (and part of the water vapor) formed in the still kettle 10 into the condenser 20. The still kettle 10 can also include a heat exchanger, which can be used to regulate the internal temperature of the still kettle 10. In particular, the heat exchanger can be a jacketed heat exchanger.

[0042] The heat exchanger of the still can include a steam-condensate pipeline, that is, steam can be introduced into the heat exchanger to heat the material in the still 10, and the condensate formed by the liquefaction of the steam can be discharged through the pipeline.

[0043] The still 10 may also include a stirring device for stirring the material added to the still 10. The still 10 may also include a drain port. This drain port may be located at the bottom of the still 10 to drain the liquid within the still 10, particularly wastewater remaining in the still 10 at the end of a production cycle. The discharged wastewater may then be further pumped by a wastewater transfer pump to a wastewater treatment tank for further treatment.

[0044] Preferably, the distillation kettle 10 can be a reactor made of explosion-proof glass-lined material, which has high acid and alkali resistance and structural strength.

[0045] The bromine extraction system may further include a sulfuric acid feed section 41, a sodium thiosulfate feed section 42, and a sodium chlorate feed section 43 connected to the still 10. The sulfuric acid feed section 41, the sodium thiosulfate feed section 42, and the sodium chlorate feed section 43 may be connected to feed ports, respectively, for introducing concentrated sulfuric acid, sodium thiosulfate, and sodium chlorate, respectively, into the still 10.

[0046] The sulfuric acid feed section 41 may include a sulfuric acid storage tank, which may be provided with a weighing module for measuring the mass of concentrated sulfuric acid introduced into the still. The sodium thiosulfate feed section 42 may include a sodium thiosulfate storage tank, and the sodium thiosulfate feed section 42 (particularly the feed line of the sodium thiosulfate feed section) may be provided with a flow meter for measuring the flow rate of the sodium thiosulfate (solution) introduced into the still. The sodium chlorate feed section 43 may include a sodium chlorate storage tank, and the sodium chlorate feed section 43 (particularly the feed line of the sodium chlorate feed section) may be provided with a flow meter for measuring the flow rate of the sodium chlorate (solution) introduced into the still.

[0047] The bromine extraction system may further include a mother liquor tank 60, which may be used to store bromine-containing wastewater. The mother liquor tank 60 may also be connected to equipment in other sections that may generate bromine-containing wastewater. The mother liquor tank 60 may be connected to the feed port of the still 10 to add bromine-containing wastewater to the still 10.

[0048] Bromine vapor formed in the still 10 can be liquefied into bromine in the condenser 20. The bromine liquefied in the condenser 20 can enter the separator 30. In particular, the condenser 20 can have a discharge port, which can be connected to the separator 30. The bromine (and some water vapor) liquefied in the condenser 20 can enter the separator 30 through the discharge port. The separator 30 can contain bromine and water, and the separator 30 can separate at least a portion of the bromine that enters the separator 30.

[0049] Preferably, condenser 20 can be a shell-and-tube condenser, i.e., a partition-type heat exchanger in which the walls of a tube bundle enclosed within a shell serve as the heat transfer surface. This type of heat exchanger (condenser) offers a simple structure, low cost, easy scale removal, and compatibility with high-temperature and high-pressure conditions. Condenser 20 can utilize circulating cooling water as its cooling medium. Preferably, the circulating cooling water has a temperature of 0 to 7 degrees Celsius.

[0050] Specifically, a bromine water outlet may be formed in the middle of the separator 30 for discharging bromine water (i.e., bromine-containing wastewater generated by the bromine extraction system) above a certain water level. A bromine outlet may be formed at the bottom of the separator 30 for discharging bromine that has settled at the bottom of the separator. It is understood that the density of bromine (liquid bromine, elemental bromine) is approximately 3.1 g / cm 3 (g / cm3), bromine enters the separator 30 containing some water and sinks to the bottom of the separator 30. Bromine is slightly soluble in water, and the upper portion of the liquid in the separator 30 may be bromine water. In addition, some bromine may react with water to produce hydrogen bromide and hypobromous acid.

[0051] The separator 30 may also be provided with a weighing module for weighing the weight of the liquid in the separator 30. It is understood that the approximate ratio of bromine to bromine water in the liquid in the separator 30 and the corresponding weight can be roughly calculated based on the specific gravity (relative density) of bromine and water.

[0052] The bromine extraction system may further include a bromine storage tank 51 and a bromine water storage tank 52. The bromine storage tank 51 may be connected to the bromine outlet at the bottom of the separator 30 for accommodating (temporarily storing) the bromine deposited at the bottom of the separator 30. The bromine water storage tank 52 may be connected to the bromine water outlet at the middle portion of the separator 30 for accommodating (temporarily storing) the bromine water overflowing from the separator 30 (when the liquid in the separator reaches the position of the bromine water outlet, the bromine water in the upper portion of the liquid may overflow from the separator bromine water outlet to the bromine water storage tank). The bromine water storage tank 52 may be connected to the feed port of the still 10 via a bromine water circulation pump to re-enter the bromine water in the bromine water storage tank 52 into the still 10 for recycling.

[0053] It can be understood that the bromine storage tank 51 and the bromine water storage tank 52 can each include a plurality of connected storage tanks, and the specific number and capacity of the storage tanks can be determined according to actual needs.

[0054] The bromine extraction system may also include an exhaust tower. One or more of the still 10, condenser 20, separator 30, bromine storage tank 51, and bromine water storage tank 52 may be connected to the exhaust tower via an exhaust gas treatment pipeline to treat any exhaust gas generated within each device. Alkali (dilute lye) may be introduced into the exhaust tower to treat the exhaust gas, particularly acidic substances present in the exhaust gas. Figure 1 The figure shows the exhaust gas treatment pipelines connecting the condenser 20, bromine storage tank 51, and bromine water storage tank 52 to the exhaust tower. It is understood that some exhaust gas treatment pipelines (such as the exhaust gas treatment pipeline connecting the still 10 to the exhaust tower) do not need to be vented when the bromine extraction system is operating normally. Venting is only required when the relevant equipment is not operating normally (for example, when the pressure in the still 10 exceeds the limit).

[0055] Preferably, the separator 30, the bromine storage tank 51 and the bromine water storage tank 52 can be steel containers, and the inner surfaces thereof can be provided with a polytetrafluoroethylene coating.

[0056] The bromine extraction system may also include a distributed control system (DCS control system), which may be an automated control system. The DCS may include a processor and sensors, measuring instruments, and the like provided on each device. The DCS may perform interlocking control of the bromine extraction system based on the operating parameters of some devices, for example, controlling the operation of downstream devices based on the operating conditions of upstream devices. Preferably, the DCS may be configured to control the opening and closing of the feed valve of the bromine storage tank 51 based on the liquid weight measured by the weighing module of the separator 30. For example, when the weight of the liquid in the separator 30 reaches 110 kg, the DCS may control the opening of the feed valve of the bromine storage tank 51 to begin discharging the bromine in the separator; when the weight of the liquid in the separator 30 is less than 85 kg, the DCS may control the closing of the feed valve of the bromine storage tank 51 to stop discharging the bromine in the separator.

[0057] It will be appreciated that the distributed control system can be used to control various devices, valves, flow controllers, and the like in the bromine extraction system, thereby controlling the entire process of the bromine extraction system. A combination of manual control and auxiliary control by the distributed control system may also be employed in certain steps of the bromine extraction system. This embodiment only illustrates the control method of the distributed control system in certain steps of the bromine extraction system.

[0058] Below, a preferred specific equipment selection of the bromine extraction system of this embodiment is given.

[0059] Table 1: Specific selection of equipment for bromine extraction system.

[0060]

[0061]

[0062] Table 1 shows the preferred main parameter specifications of some major equipment in the bromine extraction system, as well as the preferred main material types.

[0063] An exemplary method of using the bromine extraction system of this embodiment is given below.

[0064] First, bromine-containing wastewater can be added to the distillation kettle 10. The source of the bromine-containing wastewater can include bromine-containing wastewater generated in other sections and bromine-containing wastewater stored in the bromine water storage tank 52 during the previous production cycle of the bromine extraction system. The valve (vent valve) connecting the distillation kettle 10 to the exhaust tower is opened.

[0065] After the addition of the bromine-containing wastewater is complete, the stirring device of the still 10 can be turned on to begin stirring the material in the still 10. Simultaneously, the heat exchanger of the still 10 can be turned on, and a steam valve can be opened to introduce steam into the heat exchanger to increase the internal temperature of the still 10. The cooling circulating water valve of the condenser 20 can be opened to introduce cooling circulating water into the condenser to reduce the temperature within the condenser 20.

[0066] The discharge valve of the sulfuric acid storage tank of the sulfuric acid feed section 41 is opened, and the feed valve of the still 10 is opened. The distributed control system controls the relevant valves, flow regulators, and other structures to slowly add a certain amount of concentrated sulfuric acid into the still 10 and stir it for a certain period of time (for example, 20 minutes) to ensure that the materials in the still 10 are evenly mixed and remain stable.

[0067] Open the discharge valve of still kettle 10 (the discharge valve can be connected to condenser), and close the vent valve of still kettle.Open the discharge valve of the sodium chlorate storage tank of sodium chlorate feed part 43, and open the feed valve of still kettle 10.Check that the cooling water circulation of condenser 20 is normal, guarantee that the temperature of cooling water circulation remains at 0 to 7 degrees Celsius, and the internal pressure of condenser is more than 0.25MPa (megapascal).Open the feed valve of bromine water storage tank 52 and its vent valve that is connected to waste gas tower.

[0068] When the temperature inside still 10 reaches approximately 50°C (the boiling point of bromine is 58.8°C), the distributed control system controls valves and flow regulators to slowly add sodium chlorate (which reacts with the bromine-containing wastewater to form elemental bromine) into still 10. After the sodium chlorate is added, the stirring device in still 10 is stirred for a predetermined period of time (e.g., one hour).

[0069] Bromine vapor generated in the still 10 can be liquefied in the condenser 20 to form bromine (liquid bromine). The bromine can then enter the separator 30 and deposit on the inner bottom of the separator 30. The heat exchanger of the still 10 can be gradually heated (to 100 degrees Celsius). After the heat exchanger reaches a certain temperature, the distributed control system can control the relevant valves to begin the bromine separation operation. Preferably, when the weighing module of the separator 30 monitors that the liquid weight in the separator 30 reaches a certain upper threshold (e.g., 110 kg), the relevant valves can be opened to allow bromine to be introduced into the bromine storage tank 51. When the weighing module of the separator 30 monitors that the liquid weight in the separator 30 reaches a certain lower threshold (e.g., 85 kg), the relevant valves can be closed to stop the introduction of bromine into the bromine storage tank 51. It will be appreciated that the upper and lower thresholds for the liquid weight can be calculated based on the density ratio of bromine to water (bromine water), etc. (a certain amount of bromine can be retained in the separator).

[0070] When the value monitored by the weighing module of separator 30 no longer changes significantly (i.e., bromine is essentially no longer formed in the still), the distributed control system can suspend its control of the relevant valves based on the monitored value of the weighing module. Manual control is then used by staff to control the valve at the bottom of the separator connected to the bromine storage tank 51, draining the liquid in separator 30 to a certain remaining weight (for example, to 60 kg, and then passing the remaining bromine in the separator into the bromine storage tank 51). At this point, the bromine generated by the bromine extraction system has been largely collected in the bromine storage tank 51. The bromine water collected in the bromine water storage tank 52 can be fed into the next production process and passed into the still 10 again for bromine extraction.

[0071] After the bromine extraction process is complete, the still 10 can be cooled to approximately 60°C, and the discharge valve of the sodium thiosulfate storage tank in the sodium thiosulfate feed section 42 and the feed valve of the still 10 can be opened. A predetermined amount of sodium thiosulfate can be rapidly added to the still 10 via the distributed control system. After addition, the still 10 can be stirred (e.g., for one hour). It will be appreciated that the sodium thiosulfate can react (reduction reaction) with at least a portion of the remaining material in the still 10, reducing or eliminating harmful substances in the residual wastewater in the still 10.

[0072] Finally, the remaining wastewater (waste liquid) in the distillation kettle 10 can be transported to the wastewater treatment regulating tank via a wastewater delivery pump for treatment.

[0073] The following briefly describes some of the beneficial effects of the above-mentioned embodiments of the present application.

[0074] The bromine extraction system provided by the embodiment of the present application can recycle the bromine-containing wastewater generated in its production process, thereby improving the utilization rate of bromine-containing wastewater. The bromine extraction system is provided with an exhaust gas tower that can process the exhaust gas generated by each device during the production process, thereby reducing exhaust gas pollution during the bromine extraction process. The bromine extraction system adopts a distributed control system (DCS) as the main control method, which can enable each production equipment to better coordinate operations and improve production efficiency and safety factor. The application of the distributed control system, an automated control method, can effectively improve the purity of the extracted bromine compared to the traditional method of manually monitoring the reaction process and manually controlling it.

[0075] It is understood that in this application, when the number of parts or components is not specifically limited, the number may be one or more, and the term "plurality" herein refers to two or more. Where the number of parts or components is shown in the drawings and / or described in the specification as a specific number, such as two, three, or four, the specific number is generally illustrative and not restrictive, and may be understood as a plurality, i.e., two or more. However, this does not mean that this application excludes the case of one.

[0076] It should be understood that the above embodiments are merely exemplary and are not intended to limit the present application. Those skilled in the art may make various modifications and changes to the above embodiments based on the teachings of the present application without departing from the scope of the present application.

Claims

1. A bromine extraction system, characterized in that, Including still, condenser and separator, The still has a heat exchanger, and the still is capable of receiving and heating the bromine-containing liquid to form bromine vapor. The distillation kettle is connected to the condenser, and bromine vapor can be liquefied in the condenser to form bromine. The condenser is connected to the separator to pass bromine into the separator, The separator is formed with a bromine outlet and a bromine water outlet, and the bromine water outlet is directly or indirectly connected to the distillation kettle so as to pass the bromine water formed in the separator into the distillation kettle for recycling.

2. The bromine extraction system according to claim 1, characterized in that It also includes bromine storage tanks and bromine water storage tanks. The bromine storage tank is connected to the bromine outlet of the separator and is used to accommodate bromine. The bromine water storage tank is connected to the bromine water outlet of the separator and is used to contain bromine water. The bromine water storage tank is also connected to the distillation kettle for passing the bromine water stored in the bromine water storage tank into the distillation kettle for recycling.

3. The bromine extraction system according to claim 2, characterized in that Also includes exhaust tower, One or more of the distillation kettle, the condenser, the separator, the bromine storage tank, and the bromine water storage tank are connected to the exhaust gas tower via an exhaust gas treatment pipeline to treat the exhaust gas. The exhaust gas tower can contain alkaline solution for treating the exhaust gas.

4. The bromine extraction system according to claim 1, characterized in that The bromine outlet is formed at the bottom of the separator, The bromine water outlet is formed in the middle of the separator.

5. The bromine extraction system according to claim 1, characterized in that It also includes a sulfuric acid feeding section and a sodium chlorate feeding section, The sulfuric acid feed part and the sodium chlorate feed part are connected to the distillation kettle and are used to add concentrated sulfuric acid and sodium chlorate into the distillation kettle respectively.

6. The bromine extraction system according to claim 1, characterized in that It also includes a sodium thiosulfate feeding section, The sodium thiosulfate feeding part is connected to the distillation kettle and is used to add sodium thiosulfate into the distillation kettle.

7. The bromine extraction system according to claim 1, characterized in that The invention also comprises a mother liquid tank capable of storing bromine-containing waste water, wherein the mother liquid tank is connected to the distillation kettle for adding bromine-containing waste water into the distillation kettle.

8. The bromine extraction system according to claim 1, characterized in that Also included is a distributed control system comprising a processor and sensors and / or meters.

9. The bromine extraction system according to claim 8, characterized in that The separator is provided with a weighing module, which can weigh the weight of the liquid in the separator and feed back the weight information to the processor of the distributed control system for controlling the operation of the bromine extraction system.

10. The bromine extraction system according to claim 1, characterized in that The condenser is a shell and tube condenser.

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