Waste heat deep recovery type bromine extraction distillation tower system
By introducing high-efficiency low-temperature deep heat recovery device and high-temperature heat pump steam production device in the seawater bromine extraction process, the problems of easy corrosion and waste heat of traditional heat exchangers are solved, efficient recovery of waste heat and reduced steam demand are achieved, and the service life and production efficiency of the equipment are improved.
Patent Information
- Application Number
- CN202422460470.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-11
- Publication Date
- 2025-07-04
- Estimated Expiration
- 2034-10-11
AI Technical Summary
There is energy waste in the existing seawater bromine extraction process, especially the waste heat of the distilled bromine recovery liquid discharged from the bromine extraction and distillation tower cannot be effectively recovered, resulting in high steam demand and large energy consumption, and traditional heat exchangers are prone to corrosion and damage, and the equipment life is short.
The steam production device of high-efficiency low-temperature deep heat recovery device is adopted, combined with high-efficiency graphene plastic tube heat exchanger and silicon carbide heat exchanger, reduce the temperature of waste liquid and recover waste heat, and steam is produced through high-temperature heat pump to reduce steam demand.
It significantly increases the waste heat recovery, reduces steam consumption and operating costs, extends the equipment life, and realizes a seawater bromine extraction process that saves energy and consumes.
Smart Images
Figure CN223060749U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a bromine extraction distillation column system for deep waste heat recovery, belonging to the technical fields of salt chemical industry and waste heat recovery. Background Art
[0002] Salt chemical plants based on seawater salt production can extract substances such as bromine and lithium from seawater or concentrated bitter brine after salt production. The basic principle of the commonly used "air blowing method for bromine production by chlorine oxidation" is as follows.
[0003] Under acidic conditions, using chlorine as an oxidant, bromide ions (Br-) are oxidized to bromine molecules (Br2), and the ionic reaction formula is as follows.
[0004] 2Br- + Cl2 = Br2 + 2Cl-.
[0005] The free bromine is blown out by air, so it is called the air blowing method.
[0006] For acidic bromine production, sulfur dioxide is used as an absorbent, and fresh water spray is used to assist in absorbing the mixture of air and bromine. The absorption completion liquid is called primary acid, and the chemical reaction formula is as follows.
[0007] Br2 + SO2 + 2H2O = 2HBr + H2SO4.
[0008] The primary acid is introduced into chlorine for oxidation to re-free bromine and generate hydrochloric acid. The chemical reaction formula is as follows.
[0009] 2HBr + Cl2 = 2HCl + Br2.
[0010] Finally, bromine is distilled out with steam, and after condensation and separation, the finished bromine is obtained.
[0011] The process flow is described as follows.
[0012] Seawater (brine) is pumped to the blowing tower. Dilute acid and chlorine are added to the outlet pipeline of the pump. The mixed acidified and chlorinated brine sprays down from the upper part of the blowing tower. The blower blows air into the tower from the bottom. When the brine contacts the air, the free bromine in the brine is desorbed and blown out. The blowing waste liquid is discharged from the bottom of the blowing tower and enters the salt field for salt drying. The mixed gas discharged from the top of the blowing tower is sent to the absorption tower and is mixed and absorbed by sulfur dioxide and water mist. The formed completion liquid is called primary acid and is collected in the acid storage tank. The air purified by the demister is blown by the blower and enters the bottom of the blowing tower for recycling in the system. The primary acid is added from the top of the distillation tower, and steam and chlorine are introduced from the bottom of the tower. When the primary acid flows down along the packing from top to bottom, it contacts the chlorine and steam flowing from bottom to top, and is continuously oxidized and distilled. The mixture of bromine vapor and steam is discharged from the top of the tower, and after condensation and separation, liquid bromine is produced, and the crude bromine water returns to the absorption tower for continuous circulation.
[0013] Among them, chlorine gas is usually produced by vaporizing liquid chlorine through a water bath tank. The process method is as follows: Feed the liquid chlorine into the water bath bottle, and its upper nozzle is tightly connected to the chlorine gas clamp. Fill the chlorine gas water bath tank with water and use steam to heat the water in the tank. Control the temperature at 75°C - 83°C through a solenoid valve. This temperature range can achieve the vaporization of liquid chlorine and avoid the generation of nitrogen trichloride explosives. The vaporized chlorine gas is supplied out.
[0014] The preparation process of SO2 gas is as follows: Sulfur enters the sulfur combustion furnace through a distributor and burns with oxygen in the blown-in air at high temperature to generate sulfur dioxide gas. After air cooling and cooling by circulating water washing, the temperature is controlled below 70°C, and then it enters the blowing and suction tower for reduction absorption to produce the completed liquid for bromine production.
[0015] The bromine extraction and distillation process is as follows: After the completed liquid is preheated by the recycled liquid, it enters the distillation tower and is oxidized by chlorine gas. At the same time, steam distillation is carried out, and bromine is distilled out. The temperature at the top of the tower is controlled at 80 - 90°C. After condensation, crude bromine is obtained. The bromine-distilled recycled liquid is cooled by heat exchange with brine and then enters the collection pool, and then is used for brine acidification.
[0016] There are obvious energy wastes in the above traditional seawater bromine extraction process. For example, although a special heat exchanger is usually set to recover a part of the waste heat from the bromine-distilled recycled liquid discharged from the bromine extraction distillation tower, due to the very poor heat transfer performance and high cost of the original special heat exchanger, the amount of waste heat recovered is relatively small, so that the discharge temperature of the bromine-distilled recycled liquid is usually still as high as above 50 - 60°C, and the waste heat in its low-temperature section is still wasted in vain. At the same time, it leads to relatively more steam added, higher energy consumption and operating costs. In short, due to the strong corrosiveness and small flow rate of the relevant flue gas and discharged process water, a large proportion of various waste heat resources are wasted in vain, and it is necessary to recover and utilize them to achieve energy conservation and consumption reduction. Utility Model Content
[0017] The purpose and task of the present utility model are, in view of the inherent technical limitations existing in the above seawater bromine extraction process, to adopt a highly efficient low-temperature deep heat recovery device with extremely high anti-corrosion performance to greatly increase the temperature of the completed liquid, thereby greatly reducing the steam demand and achieving energy conservation and consumption reduction.
[0018] The specific description of the present utility model is as follows: A waste heat deep recovery type bromine extraction distillation tower system is composed of an original bromine extraction distillation subsystem, a waste heat deep recovery subsystem, and their connecting pipelines and components. The original bromine extraction distillation subsystem and the waste heat deep recovery subsystem include a bromine extraction distillation tower 1, a bromine vapor exhaust pipe 2, a bromine vapor condenser 3, a waste liquid pump 4, an original waste liquid heat recovery device 5, and their connecting pipelines and components. It is characterized in that the waste heat deep recovery subsystem includes a high-efficiency low-temperature deep heat recovery device 6, a high-temperature heat pump steam generation device 7, and their connecting pipelines and components. Among them, the low-temperature side inlet of the high-efficiency low-temperature deep heat recovery device 6 is communicated with the liquid supply pipe of the completed liquid 11, the low-temperature side outlet of the high-efficiency low-temperature deep heat recovery device 6 is connected to the low-temperature side inlet of the original waste liquid heat recovery device 5, the low-temperature side outlet of the original waste liquid heat recovery device 5 is connected to the liquid inlet at the upper part of the bromine extraction distillation tower 1. The lower part of the bromine extraction distillation tower 1 is provided with an inlet for chlorine gas 13 and a steam inlet. The bottom liquid outlet of the bromine extraction distillation tower 1 is connected to the inlet of the waste liquid pump 4, the outlet of the waste liquid pump 4 is connected to the high-temperature side inlet of the original waste liquid heat recovery device 5, the high-temperature side outlet of the original waste liquid heat recovery device 5 is connected to the high-temperature side inlet of the high-efficiency low-temperature deep heat recovery device 6, and the high-temperature side outlet of the high-efficiency low-temperature deep heat recovery device 6 is communicated with the drain pipe of the bromine extraction waste liquid SH; the top of the bromine extraction distillation tower 1 is an aggregation area for a mixture of bromine vapor and steam 14, and the top gas outlet is connected to the inlet at the upper part of the bromine vapor condenser 3 through the bromine vapor exhaust pipe 2. The lower liquid outlet of the bromine vapor condenser 3 is communicated with the drain pipe of liquid bromine 12, the bottom waste liquid outlet of the bromine vapor condenser 3 is communicated with the drain pipe of crude bromine water 15, the cooling water outlet of the bromine vapor condenser 3 is connected to the low-temperature heat source inlet of the high-temperature heat pump steam generation device 7 through the drain pipe of the cooling drain C2, the cooling water inlet of the bromine vapor condenser 3 is connected to the low-temperature heat source outlet of the high-temperature heat pump steam generation device 7 through the water supply pipe of the cooling water supply C1, the heating side inlet of the high-temperature heat pump steam generation device 7 is communicated with the water supply pipe of the heat pump feed water W, and the heating side outlet of the high-temperature heat pump steam generation device 7 is connected to the steam inlet of the bromine extraction distillation tower 1 and the steam inlet pipe of the external steam Q1 through the steam supply pipe of the heat pump generated steam Q2.
[0019] The high-efficiency low-temperature deep heat recovery device 6 adopts a high-efficiency graphene plastic tube heat exchanger; the original waste liquid heat recovery device 5 adopts a silicon carbide heat exchanger, a glass heat exchanger, and / or a fluoroplastic heat exchanger.
[0020] The heat pump host of the high-temperature heat pump steam generation device 7 adopts a single-stage or two-stage voltage compression type high-temperature heat pump type and generates steam.
[0021] The heat pump host of the high-temperature heat pump steam generation device 7 adopts a single-stage voltage compression type high-temperature heat pump type and generates steam in series with an electric heater.
[0022] The beneficial effects of the present utility model are as follows.
[0023] (1)In the bromine extraction distillation process, both the completed liquid and the bromine extraction waste liquid are highly corrosive, which makes it impossible to use common heat exchangers for deep waste heat recovery. Currently, only materials such as silicon carbide heat exchangers and glass heat exchangers are commonly used. Their heat transfer performance is very poor, they are expensive and prone to damage, resulting in limited waste heat recovery. The waste liquid outlet temperature is usually still 50 - 60 °C. This patent uses new high-efficiency heat exchangers such as high-efficiency graphene plastic tube heat exchangers. The temperature difference at the waste liquid outlet end can be reduced to about 5 °C. Therefore, the waste heat recovery amount can be significantly increased, and the long-term safe, reliable and stable operation of the equipment system can be ensured.
[0024] (2)This patent significantly increases the initial temperature of the completed liquid entering the bromine extraction distillation tower, thereby significantly reducing the steam heating demand and greatly reducing the steam consumption and its operating costs.
[0025] (3)Furthermore, this patent uses a high-temperature heat pump to recover the condensation heat release of the bromine vapor and water vapor mixture and produce saturated wet steam at the 0.1 - 0.2 MPa level, which can be used as part of the heating source for the bromine extraction distillation tower, thus further reducing the demand for external steam.
[0026] (4)The adoption of the above waste heat recovery process and special equipment has good anti-corrosion performance, improves the service life of the equipment, significantly reduces the full-cycle operating cost, and lays a solid technical foundation for the bromine extraction process from seawater to realize the process production mainly driven by new energy. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 is a schematic diagram of the system of the present utility model.
[0028] Figure 1 The numbers and names of each component in it are as follows.
[0029] Bromine extraction distillation tower 1, bromine vapor exhaust pipe 2, bromine vapor condenser 3, waste liquid pump 4, original waste liquid heat recovery device 5, high-efficiency low-temperature deep heat recovery device 6, high-temperature heat pump steam production device 7, completed liquid 11, liquid bromine 12, chlorine 13, bromine vapor and water vapor mixture 14, crude bromine water 15, cooling return water C2, cooling incoming water C1, external steam Q1, heat pump generated steam Q2, bromine extraction waste liquid SH, heat pump feed water W. DETAILED DESCRIPTION OF THE INVENTION
[0030] Figure 1 is a schematic diagram of the system of the present utility model and an embodiment.
[0031] The specific embodiment of the present utility model is as follows. Refer to Figure 1As shown in the figure. A bromine extraction distillation column system for deep recovery of waste heat is composed of an original bromine extraction distillation subsystem, a waste heat deep recovery subsystem, and their connecting pipelines and components. The original bromine extraction distillation subsystem and the waste heat deep recovery subsystem include a bromine extraction distillation column 1, a bromine vapor exhaust pipe 2, a bromine vapor condenser 3, a waste liquid pump 4, an original waste liquid heat recovery device 5, and their connecting pipelines and components. It is characterized in that the waste heat deep recovery subsystem includes a high-efficiency low-temperature deep heat recovery device 6, a high-temperature heat pump steam generation device 7, and their connecting pipelines and components. The low-temperature side inlet of the high-efficiency low-temperature deep heat recovery device 6 is communicated with the supply pipe of the completed liquid 11. The low-temperature side outlet of the high-efficiency low-temperature deep heat recovery device 6 is connected to the low-temperature side inlet of the original waste liquid heat recovery device 5. The low-temperature side outlet of the original waste liquid heat recovery device 5 is connected to the feed liquid inlet at the upper part of the bromine extraction distillation column 1. The chlorine 13 inlet and the steam inlet are arranged at the lower part of the bromine extraction distillation column 1. The bottom liquid outlet of the bromine extraction distillation column 1 is connected to the inlet of the waste liquid pump 4. The outlet of the waste liquid pump 4 is connected to the high-temperature side inlet of the original waste liquid heat recovery device 5. The high-temperature side outlet of the original waste liquid heat recovery device 5 is connected to the high-temperature side inlet of the high-efficiency low-temperature deep heat recovery device 6. The high-temperature side outlet of the high-efficiency low-temperature deep heat recovery device 6 is communicated with the drain pipe of the bromine extraction waste liquid SH. The top of the bromine extraction distillation column 1 is the gathering area of the bromine vapor and steam mixture 14. The top air outlet is connected to the inlet at the upper part of the bromine vapor condenser 3 through the bromine vapor exhaust pipe 2. The liquid outlet at the lower part of the bromine vapor condenser 3 is communicated with the drain pipe of the liquid bromine 12. The bottom waste liquid outlet of the bromine vapor condenser 3 is communicated with the drain pipe of the crude bromine water 15. The cooling water outlet of the bromine vapor condenser 3 is connected to the low-temperature heat source inlet of the high-temperature heat pump steam generation device 7 through the drain pipe of the cooling drain C2. The cooling water inlet of the bromine vapor condenser 3 is connected to the low-temperature heat source outlet of the high-temperature heat pump steam generation device 7 through the water supply pipe of the cooling water supply C1. The heating side inlet of the high-temperature heat pump steam generation device 7 is communicated with the water supply pipe of the heat pump water supply W. The heating side outlet of the high-temperature heat pump steam generation device 7 is connected to the steam inlet of the bromine extraction distillation column 1 and the steam inlet pipe of the external steam Q1 through the steam supply pipe of the heat pump steam production Q2.
[0032] The high-efficiency low-temperature deep heat recovery device 6 adopts a high-efficiency graphene plastic tube heat exchanger; the original waste liquid heat recovery device 5 adopts a silicon carbide heat exchanger, a glass heat exchanger, and / or a fluoroplastic heat exchanger.
[0033] The heat pump host of the high-temperature heat pump steam generation device 7 adopts a single-stage or two-stage voltage compression type high-temperature heat pump type and generates steam.
[0034] The heat pump host of the high-temperature heat pump steam generation device 7 adopts a single-stage voltage compression type high-temperature heat pump type and is connected in series with an electric heater to generate steam.
[0035] It should be noted that the present utility model is based on key technologies such as the use of a highly efficient low-temperature deep heat recovery device with extremely high anti-corrosion performance, waste heat recovery such as high-temperature heat pumps for steam production, etc., and proposes a set of new and efficient waste heat recovery type bromine extraction distillation equipment and systems. According to this solution, there can be different specific implementation measures and specific implementation devices with different structures. The above specific implementation manners are only one of the implementation forms. Any other similar simple deformed implementation manners, such as simple increase or decrease, deformation, change of relative position of internal components and interfaces, simple adjustment of relevant materials, simple combination and adjustment of external pipelines and components, etc., all fall within the protection scope of the present utility model.
Claims
1. A deep waste heat recovery type bromine extraction distillation tower system is composed of an original bromine extraction distillation subsystem, a waste heat deep recovery subsystem, and their connecting pipelines and components. The original bromine extraction distillation subsystem and the waste heat deep recovery subsystem include a bromine extraction distillation tower (1), a bromine vapor exhaust pipe (2), a bromine vapor condenser (3), a waste liquid pump (4), an original waste liquid heat recovery device (5), and their connecting pipelines and components, and is characterized in that The described waste heat deep recovery subsystem includes a high-efficiency low-temperature deep heat recovery device (6), a high-temperature heat pump steam generation device (7) and their connecting pipelines and components. Among them, the low-temperature side inlet of the high-efficiency low-temperature deep heat recovery device (6) is communicated with the liquid supply pipe of the finished liquid (11). The low-temperature side outlet of the high-efficiency low-temperature deep heat recovery device (6) is connected to the low-temperature side inlet of the original waste liquid heat recovery device (5). The low-temperature side outlet of the original waste liquid heat recovery device (5) is connected to the feed liquid inlet at the upper part of the bromine extraction distillation column (1). The lower part of the bromine extraction distillation column (1) is provided with an inlet for chlorine gas (13) and a steam inlet. The bottom liquid outlet of the bromine extraction distillation column (1) is connected to the inlet of the waste liquid pump (4). The outlet of the waste liquid pump (4) is connected to the high-temperature side inlet of the original waste liquid heat recovery device (5). The high-temperature side outlet of the original waste liquid heat recovery device (5) is connected to the high-temperature side inlet of the high-efficiency low-temperature deep heat recovery device (6). The high-temperature side outlet of the high-efficiency low-temperature deep heat recovery device (6) is communicated with the drain pipe of the bromine extraction waste liquid (SH). The top of the bromine extraction distillation column (1) is an aggregation area for the bromine vapor and steam mixture (14). The top gas outlet is connected to the inlet at the upper part of the bromine vapor condenser (3) through the bromine vapor exhaust pipe (2). The lower liquid outlet of the bromine vapor condenser (3) is communicated with the drain pipe of the liquid bromine (12). The bottom waste liquid outlet of the bromine vapor condenser (3) is communicated with the drain pipe of the crude bromine water (15). The cooling water outlet of the bromine vapor condenser (3) is connected to the low-temperature heat source inlet of the high-temperature heat pump steam generation device (7) through the drain pipe of the cooling drain water (C2). The cooling water inlet of the bromine vapor condenser (3) is connected to the low-temperature heat source outlet of the high-temperature heat pump steam generation device (7) through the water supply pipe of the cooling incoming water (C1). The heating side inlet of the high-temperature heat pump steam generation device (7) is communicated with the water supply pipe of the heat pump feed water (W). The heating side outlet of the high-temperature heat pump steam generation device (7) is connected to the steam inlet of the bromine extraction distillation column (1) and the steam inlet pipe of the external steam (Q1) through the steam supply pipe of the heat pump generated steam (Q2).
2. The waste heat deep recovery type bromine extraction distillation column system according to claim 1, characterized in that The described high-efficiency low-temperature deep heat recovery device (6) adopts a high-efficiency graphene plastic pipe heat exchanger; the original waste liquid heat recovery device (5) adopts a silicon carbide heat exchanger, a glass heat exchanger and / or a fluoroplastic heat exchanger.
3. The waste heat deep recovery type bromine extraction distillation column system according to claim 1, characterized in that The heat pump host of the described high-temperature heat pump steam generation device (7) adopts a single-stage or two-stage voltage compression type high-temperature heat pump and generates steam.
4. The system of a bromine extraction distillation column for deep recovery of waste heat as claimed in claim 1, wherein The heat pump host of the described high-temperature heat pump steam generation device (7) adopts a single-stage voltage compression type high-temperature heat pump and is connected in series with an electric heater to generate steam.