System for extracting bromine from brine

Abstract

The application discloses a system for extracting bromine from brine, comprising a contact tower, a brine supply pipeline, a chlorine supply pipeline, a steam supplement pipeline, a brine discharge pipeline, a bromine lead-out pipeline, a gas-liquid separation mechanism, a first heater allowing fluid to pass through is arranged in the internal section of the contact tower between the brine supply inlet and the chlorine supply inlet, and a second heater allowing fluid to pass through is arranged in the internal section of the contact tower between the steam supply inlet and the chlorine supply inlet; the first heater is used for heating the falling brine to a boiling state so that the brine is contacted with chlorine in the boiling state; and the second heater is used for heating the brine after being contacted with chlorine so that part of the brine is vaporized to form steam.

Description

Technical Field

[0001] This invention relates to a system for extracting bromine from brine. Background Technology

[0002] Steam distillation is a classic process for extracting bromine from bromine-containing brine. The core equipment for bromine extraction using steam distillation is a contact tower (or reaction tower). The typical process flow for bromine extraction using steam distillation is as follows: liquid water is heated into steam, which is then supplied to the contact tower from the bottom via a pipeline. Chlorine gas is also supplied to the contact tower from the middle wall via a pipeline. The brine (raw material) is heated to near boiling point, and then supplied to the contact tower from the top via a pipeline. In the contact tower, the falling brine reacts with the chlorine gas to convert bromide ions in the sodium bromide into bromine. The steam is used to extract the bromine from the liquid phase brine (i.e., the gas extraction process). The extracted bromine, mixed with steam and chlorine gas, is led out via a pipeline connected to the top of the contact tower. The extracted bromine is then separated into liquid bromine by a gas-liquid separator.

[0003] The existing processes and related equipment for bromine extraction have the following drawbacks: On the one hand, before the brine is fed into the contact tower, it needs to be heated to a boiling state. Otherwise, it will be difficult for the brine to come into contact with chlorine gas in a boiling or near-boiling state in order to improve the efficiency of steam in removing bromine. However, due to heat loss during the transportation of the brine and during its descent in the contact tower, it is difficult for the brine to come into contact with chlorine gas in a boiling or near-boiling state, thus affecting the efficiency of bromine removal. In addition, a separate heating device is required to heat the brine.

[0004] On the other hand, because the brine is difficult to boil or is close to boiling, and because of the chlorine, a larger amount of steam needs to be provided, thus increasing the consumption of steam.

[0005] To address the aforementioned problems, US Patent Application No. US06622197 provides a patent that solves these problems. The core technology of the patent is to create a negative pressure state inside the contact tower, thereby lowering the boiling point of the brine and causing the brine inside the contact tower to boil or nearly boil.

[0006] However, the technical solutions provided by the aforementioned patents still have the following shortcomings: 1. Although the brine can be brought to a boil or near-boiling state by drawing it into a negative pressure state through the contact tower, this increases the cost of configuring the sealing structure and equipment, as well as the cost of treating the extracted gas.

[0007] 2. Before the brine is supplied to the contact tower, it still needs to be heated and a large amount of external steam needs to be provided, resulting in still a large energy consumption. Summary of the Invention

[0008] To address the aforementioned technical problems in the prior art, the present invention provides a system for extracting bromine from brine.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A system for extracting bromine from brine includes: a contact tower; a brine supply inlet connected to the upper tower wall for supplying brine to the contact tower; a chlorine supply inlet connected to the middle tower wall for supplying chlorine to the contact tower; a steam replenishment inlet connected to the lower tower wall for selectively supplying steam to the contact tower; a brine discharge pipeline extending from the bottom of the contact tower for discharging brine waste; a bromine discharge pipeline extending from the top of the contact tower for discharging a bromine-containing mixed gas; and a gas-liquid separation mechanism for liquefying gaseous bromine into liquid brine, wherein: The internal section of the contact tower between the brine inlet and the chlorine inlet is equipped with a first heater that allows fluid to pass through, and the internal section of the contact tower between the steam inlet and the chlorine inlet is equipped with a second heater that allows fluid to pass through; The first heater is used to heat the falling brine to a boiling state so that the brine comes into contact with chlorine gas in a boiling state. The second heater is used to heat the brine after it has come into contact with chlorine gas so that part of the brine is vaporized to form steam.

[0010] Preferably, the first heater includes multiple layers of screens arranged vertically at intervals, each screen being woven from heating wires.

[0011] Preferably, the second heater is formed by spirally rolling an electric heating metal plate, and the brine passes through the spiral gaps of the electric heating metal plate; wherein: The sidewalls of the metal plates on both sides of the spiral gap are configured with an alternating concave-convex structure to increase the contact area between the brine passing through the spiral gap and the metal plates.

[0012] Preferably, the gas-liquid separation mechanism includes a cooling module and a gas-liquid separation container. The bromine outlet pipeline is connected to the gas-liquid separation container. The cooling module is arranged on the bromine outlet pipeline to cool the bromine-containing mixed gas inside the pipeline. The gas-liquid separation container is used to receive the cooled liquid bromine and the bromine-containing mixed gas. Wherein: A first recovery pipeline extends from the top of the gas-liquid separation vessel and is connected to the internal section of the contact tower where the chlorine inlet is located.

[0013] Preferably, the system further includes a waste storage device, and the brine discharge pipeline is connected to the top of the waste storage device to supply brine waste into the waste storage device; wherein: The waste storage container is equipped with a stirrer for stirring brine waste, and a heating module for heating brine waste is provided outside the waste storage container. A second recovery pipeline is sequentially introduced from the top of the waste storage device, and the second recovery pipeline is connected to the internal section of the contact sleeve where the chlorine supply inlet is located.

[0014] Preferably, a brine supply branch line is led out from the brine supply pipeline and connected to the top of the contact tower to cool the bromine-containing mixed gas by supplying brine to the top of the contact tower; a first check valve is provided on the brine supply branch line, which allows fluid to flow to the top of the contact tower and then shuts it off in the reverse direction.

[0015] Preferably, an electric heater is installed on the brine supply pipeline downstream of the brine supply branch line, and the electric heater is used to preheat the brine in the brine supply pipeline.

[0016] Preferably, the internal section of the contact tower between the first heater and the brine inlet is filled with a first fluid dispersion packing that allows fluid to pass through.

[0017] Preferably, the interior of the top of the contact tower is filled with a second fluid dispersion packing that allows fluid to pass through.

[0018] Preferably, a second check valve is provided on the first recovery pipeline, which allows fluid to flow towards the contact tower and shuts it off in the reverse direction; a third check valve is provided on the second recovery pipeline, which allows fluid to flow towards the contact tower and shuts it off in the reverse direction.

[0019] Compared with existing technologies, the beneficial effects of the system for extracting bromine from brine disclosed in this invention are: 1. By installing a first heater inside the contact tower, the brine that is about to come into contact with chlorine is heated to a boiling state, so that the brine can always be in contact with chlorine at a boiling state, thereby improving the extraction efficiency of bromine and reducing heat loss.

[0020] 2. By installing a second heater inside the contact tower, located below the first heater, a portion of the brine is vaporized into water vapor. This water vapor is then used to extract bromine, while externally supplied water vapor is only used as a supplement when steam is insufficient. Furthermore, the heating effect of the second heater causes the water vapor to flow rapidly, thereby improving the extraction efficiency of the bromine.

[0021] The overview of various implementations or examples of the technology described in this invention is not a complete disclosure of the full scope or all features of the disclosed technology. Attached Figure Description

[0022] In drawings that are not necessarily drawn to scale, the same reference numerals may describe similar parts in different views. The same reference numerals with or without letter suffixes may indicate different instances of similar parts. The drawings generally illustrate various embodiments by way of example rather than limitation and, together with the description and claims, serve to explain embodiments of the invention. Where appropriate, the same reference numerals are used in all drawings to refer to the same or similar parts. Such embodiments are illustrative and not intended to be exhaustive or exclusive embodiments of the apparatus or method.

[0023] Figure 1 This is a schematic diagram illustrating the working principle of the system for extracting bromine from brine provided by the present invention.

[0024] Figure 2 for Figure 1 A magnified view of part A.

[0025] Figure label: 10-Contact tower; 11-Brine inlet; 12-Chlorine inlet; 13-Steam inlet; 21-Brine supply pipeline; 22-Chlorine supply pipeline; 23-Steam replenishment pipeline; 24-Bromine outlet pipeline; 25-Brine discharge pipeline; 26-First recovery pipeline; 27-Second recovery pipeline; 28-Brine supply branch line; 31-Cooling module; 32-Gas-liquid separation container; 41-First heater; 411-Screen; 42-Second heater; 421-Metal plate; 422-Concave-convex; 51-First fluid dispersion packing; 52-Second fluid dispersion packing; 60-Waste temporary storage; 61-Agitator; 62-Heating module; 71-First check valve; 72-Second check valve; 73-Third check valve; 80-Electric heater. Detailed Implementation

[0026] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0027] To keep the following description of the embodiments of the present invention clear and concise, detailed descriptions of known functions and known components are omitted.

[0028] like Figure 1 As shown, the present invention discloses a system for extracting bromine from brine. The system includes: a contact tower 10, a brine supply pipeline 21, a chlorine supply pipeline 22, a steam replenishment pipeline 23, a bromine outlet pipeline 24, a brine discharge pipeline 25, a first recovery pipeline 26, a second recovery pipeline 27, a brine supply branch line 28, a cooling module 31, a gas-liquid separator, a waste storage tank 60, and an electric heater 80.

[0029] The upper wall of the contact tower 10 is equipped with a brine inlet 11. A brine supply pipeline 21 is connected to the brine inlet 11 and is used to supply bromine-containing brine to the interior of the contact tower 10. A brine supply branch line 28 is led out from the brine supply pipeline 21 and is connected to the top of the contact tower 10 to supply unheated room-temperature brine to the interior of the contact tower 10. A first check valve 71 is provided on the brine supply branch line 28, which allows brine to flow into the contact tower 10 and back. Up to the end, an electric heater 80 is installed on the brine supply pipeline 21 downstream of the brine supply branch 28, which is used to preheat the brine; a chlorine inlet 12 is provided on the middle tower wall of the contact tower 10, and a chlorine supply pipeline 22 is connected to the chlorine inlet 12 to supply chlorine to the interior of the contact tower 10; a steam inlet 13 is provided on the lower tower wall of the contact tower 10, and a steam supplement pipeline 23 drawn from the steam source is connected to the steam inlet 13 to supply steam to the interior of the contact tower 10 as needed.

[0030] A bromine outlet line 24 is led out from the top of the contact tower 10, and the far end of the bromine outlet line 24 is connected to the top of the gas-liquid separation vessel 32. A cooling module 31 is arranged on the bromine outlet line 24 to cool the fluid in the bromine outlet line 24. A first recovery line 26 is led out from the top of the gas-liquid separation vessel 32 and communicates with the internal section of the contact tower 10 where the chlorine inlet 12 is located. A second check valve 72 is arranged on the first recovery line 26, which allows the fluid in the first recovery line 26 to flow to the contact tower 10 and is blocked in the reverse direction.

[0031] A brine discharge pipeline 25 is led out from the bottom of the contact tower 10 and connected to the top of the waste storage tank 60. An agitator 61 extends into the waste storage tank 60 to agitate the interior of the waste storage tank 60. A heating module 62 is arranged on the outside of the waste storage tank 60 to heat the interior of the waste storage tank 60. A second recovery pipeline 27 is led out from the top of the waste storage tank 60. A third check valve 73 is installed on the second recovery pipeline 27. The third check valve 73 allows the fluid in the second recovery pipeline 27 to flow towards the contact tower 10 and then shuts it off in the reverse direction.

[0032] The internal structure of the contact tower 10 is as follows: A first heater 41 is installed in the internal section of the contact tower 10 between the brine inlet 11 and the chlorine inlet 12. The first heater 41 has a porous structure that allows fluid to pass through. The first heater 41 is closer in height to the chlorine inlet 12. The brine entering the contact tower 10 and falling through the first heater 41 is heated to a boiling state (i.e., heated to about 100°C). A second heater 42 is installed in the internal section of the contact tower 10 between the brine inlet 11 and the steam inlet 13. The second heater 42 has a porous structure that allows fluid to pass through. The second heater 42 is closer in height to the chlorine inlet 12. After falling through the second heater 42, part of the brine forms steam.

[0033] The internal section of the contact tower 10 between the first heater 41 and the brine inlet 11 is filled with a first fluid dispersion packing 51. The first fluid dispersion packing 51 is used to uniformly disperse the brine on the cross-section of the contact tower 10, so that the brine passes through the first heater 41 evenly. The top section of the contact tower 10 is filled with a second fluid dispersion packing 52. The second fluid dispersion packing is used to disperse the ambient temperature brine from the top of the contact tower 10.

[0034] The working process of the above system is described below.

[0035] Room temperature brine flows along brine supply line 21 to contact tower 10. Before entering the upper section of contact tower 10, the brine is preheated by electric heater 80. The preheating temperature does not need to be too high; for example, it can be 70-80°C. The brine entering the upper section of contact tower 10 falls under the influence of gravity. At the same time, chlorine gas enters the middle section of contact tower 10 along chlorine gas supply line 22, between the first heater 41 and the second heater 42.

[0036] The brine falls through the first fluid dispersion packing 51, which disperses the brine, ensuring that falling brine exists in all areas of the contact tower 10 cross-section after passing through the packing. The brine continues to fall through the first heater 41, which heats it to a boiling state, ensuring that it is essentially boiling after passing through the heater. The boiling brine encounters chlorine gas in the middle section of the contact tower 10, converting bromide ions in the sodium bromide into bromine (bromine gas). After contacting the chlorine gas, the brine continues to fall through the second heater 42, which heats the brine, causing some of the water in the brine to vaporize. Under heating, this vapor rises rapidly, allowing the bromine gas to be released.

[0037] The bromine, water vapor, and some unreacted chlorine flow upwards and are drawn out through the bromine outlet pipeline 24 after passing through the second fluid dispersion packing 52. When passing through the second fluid dispersion packing 52, the brine from the brine supply branch 28 and uniformly dispersed by the second fluid dispersion packing 52 cools and washes the bromine, water vapor, and some unreacted chlorine, thereby washing away most of the water vapor and chlorine. Therefore, the gas drawn out through the bromine outlet pipeline 24 is mostly bromine.

[0038] If the steam generated by the second heater 42 is insufficient (this can be determined by monitoring the pressure and flow rate in the chlorine outlet pipeline), steam can be supplied to the contact tower 10 via the steam supply pipeline 23.

[0039] The bromine-containing mixed gas flowing through the bromine outlet pipeline 24 passes through the cooling module 31, which condenses most of the gaseous bromine into liquid bromine. The condensed fluid flows into the gas-liquid separation container 32 for settling, and the liquid bromine in the gas-liquid separation container 32 is periodically transported to the bromine storage device.

[0040] The unliquefied portion of bromine and most of the chlorine are transported back to the internal section between the first heater 41 and the second heater 42 of the contact tower 10 via the first recovery pipeline 26, and re-participate in the extraction of bromine.

[0041] After passing through the second heater 42, the brine waste flows from the bottom of the contact tower 10 into the waste storage tank 60 via the brine discharge pipeline 25. The agitator 61 in the waste storage tank 60 stirs the brine waste, while the heating module 62 outside the waste storage tank 60 heats the brine waste, causing the chlorine and bromine dissolved in it to precipitate. The second recovery pipeline 27 then transports the precipitated chlorine and bromine back to the internal section between the first heater 41 and the second heater 42 of the contact tower 10, where they are re-extracted for bromine extraction.

[0042] The first heater 41 is preferably configured as follows: like Figure 1 As shown, the first heater 41 consists of multiple layers of screens 411 arranged vertically at intervals. Each layer of screen 411 is woven from heating wires. Brine falls through the mesh of the screens 411, and the heating wires heat the brine as it passes through the screens. The advantages of this structure of the first heater 41 are: on the one hand, it can heat the brine evenly; on the other hand, it increases the contact area between the brine and chlorine gas by further dispersing the brine.

[0043] The second heater 42 is preferably configured as follows: like Figure 1 and combined Figure 2 As shown, the second heater 42 is formed by spirally rolling an electric heating metal plate 421, through which brine passes. The sidewalls of the metal plate 421 on both sides of the spiral gap are configured with alternating concave and convex structures 422. The advantage of this structure for the second heater 42 is that the concave and convex sidewalls have a certain obstruction effect on the brine; in other words, the concave and convex sidewalls are more likely to receive the brine, thereby allowing the sidewalls to quickly heat the brine falling on them, thus enabling that portion of the brine to quickly form steam.

[0044] The advantages of the system for extracting bromine from brine provided by this invention are: 1. By installing a first heater 41 inside the contact tower 10, the brine that is about to come into contact with chlorine gas is heated to a boiling state by the first heater 41, so that the brine can always be in contact with chlorine gas in a boiling state, thereby improving the extraction efficiency of bromine and reducing heat loss.

[0045] 2. By installing a second heater 42 inside the contact tower 10, located below the first heater 41, a portion of the brine is vaporized into water vapor. This water vapor is then used to extract bromine, while externally supplied water vapor is only used as a supplement when steam is insufficient. Furthermore, the heating effect of the second heater 42 causes the water vapor to flow rapidly, thereby improving the extraction effect on bromine.

[0046] Furthermore, although exemplary embodiments have been described in this invention, their scope includes any and all embodiments based on the invention that have equivalent elements, modifications, omissions, combinations (e.g., schemes involving intersections of various embodiments), adaptations, or alterations. Elements in the claims will be interpreted broadly based on the language used in the claims and are not limited to the examples described in this specification or during the implementation of this application, and such examples will be interpreted as non-exclusive. Therefore, this specification and examples are intended to be considered illustrative only, and the true scope and spirit are indicated by the full scope of the following claims and their equivalents.

[0047] The above description is intended to be illustrative and not restrictive. For example, the above examples (or one or more of them) can be used in combination with each other. Other embodiments may be used by those skilled in the art upon reading the above description. Furthermore, in the above detailed description, various features may be grouped together to simplify the invention. This should not be construed as an intention that a disclosed feature, which is not claimed, is necessary for any claim. Rather, the subject matter of the invention may be less than all the features of the particular disclosed embodiment. Thus, the following claims are incorporated herein by reference as examples or embodiments, wherein each claim is independently considered as a separate embodiment, and these embodiments are contemplated as being possible in various combinations or arrangements. The scope of the invention should be determined by reference to the appended claims and the full scope of their equivalents.

[0048] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its spirit and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of the present invention.

Claims

1. A system for extracting bromine from brine, characterized in that, include: The system includes: a contact tower; a brine supply pipeline connected to the upper tower wall for supplying brine to the contact tower; a chlorine supply pipeline connected to the middle tower wall for supplying chlorine to the contact tower; a steam supply pipeline connected to the lower tower wall for supplying steam to the contact tower as needed; a brine discharge pipeline extending from the bottom of the contact tower for discharging brine waste; a bromine discharge pipeline extending from the top of the contact tower for discharging a bromine-containing mixed gas; and a gas-liquid separation mechanism for liquefying gaseous bromine into liquid brine, wherein: The internal section of the contact tower between the brine inlet and the chlorine inlet is equipped with a first heater that allows fluid to pass through, and the internal section of the contact tower between the steam inlet and the chlorine inlet is equipped with a second heater that allows fluid to pass through; The first heater is used to heat the falling brine to a boiling state so that the brine comes into contact with chlorine gas in a boiling state. The second heater is used to heat the brine after it has come into contact with chlorine gas so that part of the brine is vaporized to form steam.

2. The system for extracting bromine from brine according to claim 1, characterized in that, The first heater includes multiple layers of screens arranged vertically at intervals, each screen being woven from heating wires.

3. The system for extracting bromine from brine according to claim 1, characterized in that, The second heater is formed by spirally rolling an electric heating metal plate, through which brine passes; wherein: The sidewalls of the metal plates on both sides of the spiral gap are configured with an alternating concave-convex structure to increase the contact area between the brine passing through the spiral gap and the metal plates.

4. The system for extracting bromine from brine according to claim 1, characterized in that, The gas-liquid separation mechanism includes a cooling module and a gas-liquid separation container. The bromine outlet pipeline is connected to the gas-liquid separation container. The cooling module is arranged on the bromine outlet pipeline to cool the bromine-containing mixed gas inside the pipeline. The gas-liquid separation container is used to receive the cooled liquid bromine and the bromine-containing mixed gas. Wherein: A first recovery pipeline extends from the top of the gas-liquid separation vessel and is connected to the internal section of the contact tower where the chlorine inlet is located.

5. The system for extracting bromine from brine according to claim 4, characterized in that, The system also includes a waste storage tank, and the brine discharge pipeline is connected to the top of the waste storage tank to supply brine waste into the waste storage tank; wherein: A stirrer for stirring brine waste is inserted into the waste storage container, and a heating module for heating the brine waste is provided outside the waste storage container. A second recovery pipeline is sequentially introduced from the top of the waste storage device, and the second recovery pipeline is connected to the internal section of the contact sleeve where the chlorine gas supply inlet is located.

6. The system for extracting bromine from brine according to claim 1, characterized in that, A brine supply branch line is drawn from the brine supply pipeline and connected to the top of the contact tower to cool the bromine-containing mixed gas by supplying brine to the top of the contact tower; a first check valve is provided on the brine supply branch line, which allows fluid to flow to the top of the contact tower and then shuts it off in the reverse direction.

7. The system for extracting bromine from brine according to claim 6, characterized in that, An electric heater is installed on the brine supply pipeline downstream of the brine supply branch line. The electric heater is used to preheat the brine in the brine supply pipeline.

8. The system for extracting bromine from brine according to claim 1, characterized in that, The internal section of the contact tower between the first heater and the brine inlet is filled with a first fluid dispersion packing that allows fluid to pass through.

9. The system for extracting bromine from brine according to claim 6, characterized in that, The interior of the top of the contact tower is filled with a second fluid dispersion packing that allows fluid to pass through.

10. The system for extracting bromine from brine according to claim 5, characterized in that, A second check valve is installed on the first recovery pipeline, which allows fluid to flow towards the contact tower and shuts it off in the reverse direction. A third check valve is installed on the second recovery pipeline, which allows fluid to flow towards the contact tower and shuts it off in the reverse direction.

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