Energy-saving efficient evaporation system for nitrogen trifluoride production sewage

Abstract

The utility model discloses an energy-saving efficient evaporation system for nitrogen trifluoride production sewage. The energy-saving efficient evaporation system comprises a potassium fluoride waste liquid treatment unit, a sodium sulfate waste liquid treatment unit, a calcium chloride waste liquid treatment unit, a salt-rich water waste liquid treatment unit, a crystal evaporation separation unit, a crystal collection unit and a backwashing unit. The system disclosed by the utility model is used for separately treating four kinds of sewage, namely potassium fluoride waste liquid, sodium sulfate waste liquid, calcium chloride waste liquid and salt-rich water waste liquid generated in a nitrogen trifluoride production process to obtain multiple crystal products with single components, so that hazardous wastes and solid wastes are separately recycled, and the quantity of hazardous waste products and the treatment cost are reduced; one set of evaporation system is shared for intermittent treatment, so that the product production cost is reduced, the energy is saved, the consumption is reduced, the equipment production allowance is reasonably used, and the equipment utilization rate is improved.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology for nitrogen trifluoride production, specifically an energy-saving and efficient evaporation system for nitrogen trifluoride production wastewater. Background Technology

[0002] Currently, the wastewater generated in the nitrogen trifluoride production process is diverse. Existing wastewater treatment plants use evaporation systems that mix different solid waste and hazardous waste solutions for comprehensive treatment. This results in the evaporation of mixed crystals containing hazardous waste media. These mixed crystals are classified as hazardous waste and cannot be recycled, leading to an increase in the amount of hazardous waste products, an increased safety hazard factor, increased production costs for enterprises, and an increased environmental impact factor. Secondary treatment of the mixed crystals is required, which in turn leads to a higher overall wastewater treatment cost. Utility Model Content

[0003] This invention addresses the problems mentioned in the background section by providing an energy-efficient and high-performance evaporation system for nitrogen trifluoride production wastewater. This system is used to separately treat different types of wastewater solutions during nitrogen trifluoride production, obtaining single-component crystals that can be directly recycled, thereby reducing the amount of hazardous waste and treatment costs.

[0004] This utility model provides an energy-saving and high-efficiency evaporation system for nitrogen trifluoride production wastewater, comprising:

[0005] A potassium fluoride waste liquid treatment unit includes a potassium fluoride waste liquid tank, a first booster pump, and a first pH adjustment tank connected in sequence by pipelines.

[0006] A sodium sulfate waste liquid treatment unit includes a sodium sulfate waste liquid tank, a second lift pump, and a second pH adjustment tank connected in sequence by pipelines.

[0007] A calcium chloride waste liquid treatment unit includes a calcium chloride waste liquid tank, a third booster pump, and a third pH adjustment tank connected in sequence by pipelines.

[0008] The saline waste liquid treatment unit includes a saline waste liquid tank, a fourth lift pump, and a fourth pH adjustment tank connected in sequence by pipelines.

[0009] The crystallization evaporation separation unit includes a multi-effect evaporator and a centrifuge connected to each other by pipes. The liquid inlet of the multi-effect evaporator is connected to the first pH adjustment tank, the second pH adjustment tank, the third pH adjustment tank and the fourth pH adjustment tank, respectively.

[0010] The crystallization collection unit includes a potassium fluoride crystal collection tank, a sodium sulfate crystal collection tank, a calcium chloride crystal collection tank, and a sodium chloride crystal collection tank. The potassium fluoride crystal collection tank, sodium sulfate crystal collection tank, calcium chloride crystal collection tank, and sodium chloride crystal collection tank are respectively connected to a centrifuge via pipelines.

[0011] Furthermore, a first valve, a second valve, a third valve, and a fourth valve are respectively installed on each pipeline between the first pH adjustment tank, the second pH adjustment tank, the third pH adjustment tank, the fourth pH adjustment tank and the multi-effect evaporator.

[0012] Furthermore, a fifth valve, a sixth valve, a seventh valve, and an eighth valve are respectively installed on each pipeline between the centrifuge and the potassium fluoride crystal collection tank, the sodium sulfate crystal collection tank, the calcium chloride crystal collection tank, and the sodium chloride crystal collection tank.

[0013] Furthermore, the multi-effect evaporator is a triple-effect evaporator.

[0014] Furthermore, it also includes a backwashing unit, which includes a backwash water inlet pipe and a backwash water outlet pipe. The inlet end of the backwash water inlet pipe is connected to a water source, the outlet end of the backwash water inlet pipe is connected to a centrifuge, the inlet end of the backwash water outlet pipe is connected to a multi-effect evaporator, and the outlet end of the backwash water outlet pipe is connected to a potassium fluoride waste liquid tank, a sodium sulfate waste liquid tank, a calcium chloride waste liquid tank, and a rich saline waste liquid tank through four branch pipes respectively. The four branch pipes are respectively equipped with a first backwash water outlet valve, a second backwash water outlet valve, a third backwash water outlet valve, and a fourth backwash water outlet valve.

[0015] Compared with the prior art, the beneficial technical effects of this utility model are as follows:

[0016] This utility model relates to an energy-saving and efficient evaporation system for nitrogen trifluoride production wastewater. This system separately treats four types of wastewater generated during nitrogen trifluoride production: potassium fluoride wastewater, sodium sulfate wastewater, calcium chloride wastewater, and saline wastewater. The resulting wastewater yields multiple crystalline products with single components, thus separating and recycling hazardous and solid waste, reducing the amount of hazardous waste and treatment costs. The system uses a single evaporation system for intermittent processing, reducing production costs, saving energy, utilizing equipment capacity efficiently, and improving equipment utilization. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an energy-saving and high-efficiency evaporation system for nitrogen trifluoride production wastewater according to the present invention;

[0018] In the diagram: 101-Potassium fluoride waste tank, 102-First booster pump, 103-First pH adjustment tank, 104-First valve, 201-Sodium sulfate waste tank, 202-Second booster pump, 203-Second pH adjustment tank, 204-Second valve, 301-Calcium chloride waste tank, 302-Third booster pump, 303-Third pH adjustment tank, 304-Third valve, 401-Rich brine waste tank, 402-Fourth booster pump, 403-Fourth pH adjustment tank, 404-Fourth valve, 5-Multi-effect distillation 6-Centrifuge, 701-Potassium fluoride crystal collection tank, 702-Sodium sulfate crystal collection tank, 703-Calcium chloride crystal collection tank, 704-Sodium chloride crystal collection tank, 705-Fifth valve, 706-Sixth valve, 707-Seventh valve, 708-Eighth valve, 8-Backwash water inlet pipe, 801-Backwash inlet valve, 9-Backwash outlet pipe, 901-First backwash outlet valve, 902-Second backwash outlet valve, 903-Third backwash outlet valve, 904-Fourth backwash outlet valve. Detailed Implementation

[0019] To more clearly illustrate the technical solution and effects of this utility model, the present utility model will be clearly and completely described below with reference to the accompanying drawings and embodiments. It should be understood that the embodiments described herein are merely some embodiments of this utility model, not all embodiments, and the technical features involved in the various embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0020] It should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] It should be noted that, unless otherwise explicitly specified and limited, the terms “installation,” “connection,” “linking,” and “setting” should be interpreted broadly. For example, they can refer to fixed connection or setting, detachable connection or setting, or integral connection or setting; they can refer to direct connection or indirect connection through an intermediate medium; and they can refer to the internal connection of two components.

[0022] Example

[0023] Please see Figure 1This embodiment provides an energy-saving and efficient evaporation system for nitrogen trifluoride production wastewater, including a potassium fluoride wastewater treatment unit, a sodium sulfate wastewater treatment unit, a calcium chloride wastewater treatment unit, a saline wastewater treatment unit, a crystallization evaporation separation unit, a crystallization collection unit, and a backwashing unit.

[0024] Specifically, the potassium fluoride waste liquid treatment unit includes a potassium fluoride waste liquid tank 101, a first booster pump 102, and a first pH adjustment tank 103 connected in sequence via pipelines; the sodium sulfate waste liquid treatment unit includes a sodium sulfate waste liquid tank 201, a second booster pump 202, and a second pH adjustment tank 203 connected in sequence via pipelines; the calcium chloride waste liquid treatment unit includes a calcium chloride waste liquid tank 301, a third booster pump 302, and a third pH adjustment tank 303 connected in sequence via pipelines; the saline waste liquid treatment unit includes a saline waste liquid tank 401, a fourth booster pump 402, and a fourth pH adjustment tank 403 connected in sequence via pipelines; the crystallization evaporation separation unit includes a multi-effect evaporator 5 and a centrifuge 6 connected to each other via pipelines, with the inlet end of the multi-effect evaporator 5 connected to the first pH adjustment tank 103, the second pH adjustment tank 203, the third pH adjustment tank 303, and the fourth pH adjustment tank 403 respectively; the crystallization collection... The collection unit includes a potassium fluoride crystal collection tank 701, a sodium sulfate crystal collection tank 702, a calcium chloride crystal collection tank 703, and a sodium chloride crystal collection tank 704. These tanks are connected to the centrifuge 6 via pipes. The backwashing unit includes a backwash water inlet pipe 8 and a backwash water outlet pipe 9. The inlet end of the backwash water inlet pipe 8... The water source is connected, and the outlet of the backwash water inlet pipe 8 is connected to the centrifuge 6. The inlet of the backwash water outlet pipe 9 is connected to the multi-effect evaporator 5. The outlet of the backwash water outlet pipe 9 is connected to the potassium fluoride waste liquid tank 101, sodium sulfate waste liquid tank 201, calcium chloride waste liquid tank 301, and rich saline waste liquid tank 401 through four branch pipes. The four branch pipes are respectively equipped with a first backwash water outlet valve 901, a second backwash water outlet valve 902, a third backwash water outlet valve 903, and a fourth backwash water outlet valve 904.

[0025] Specifically, a first valve 104, a second valve 204, a third valve 304, and a fourth valve 404 are respectively installed on each pipe between the first pH adjustment tank 103, the second pH adjustment tank 203, the third pH adjustment tank 303, the fourth pH adjustment tank 403 and the multi-effect evaporator 5; a fifth valve 705, a sixth valve 706, a seventh valve 707 and an eighth valve 708 are respectively installed on each pipe between the centrifuge 6 and the potassium fluoride crystal collection tank 701, the sodium sulfate crystal collection tank 702, the calcium chloride crystal collection tank 703 and the sodium chloride crystal collection tank 704.

[0026] In this embodiment, the multi-effect evaporator 5 is a triple-effect evaporator.

[0027] The wastewater generated during the production of nitrogen trifluoride mainly consists of four types: potassium fluoride wastewater, sodium sulfate wastewater, calcium chloride wastewater, and saline wastewater. The energy-saving and efficient evaporation system for nitrogen trifluoride production wastewater in this embodiment can achieve separate treatment of these four types of wastewater.

[0028] The working principle of this invention is as follows: First valve 104 and fifth valve 705 are opened, while the remaining valves are closed. Potassium fluoride waste liquid from potassium fluoride waste liquid tank 101 is injected into first pH adjustment tank 103 via first booster pump 102 for pH adjustment. Then, it enters multi-effect evaporator 5 for multiple distillations. The waste liquid containing crystals is separated into potassium fluoride crystals by centrifuge 6 and sent to potassium fluoride crystal collection tank 701, completing the potassium fluoride wastewater treatment. First valve 104 and fifth valve 705 are closed, and backwash inlet valve 801 and first backwash outlet valve 901 are opened to clean centrifuge 6, multi-effect evaporator 5, and pipelines. The cleaned water is sent to potassium fluoride waste liquid tank 101, completing the equipment and pipeline cleaning. Following the above method, sodium sulfate waste liquid, calcium chloride waste liquid, and salt-rich waste liquid are treated respectively. Through intermittent treatment using a shared evaporation system, single-component potassium fluoride crystals, sodium sulfate crystals, calcium chloride crystals, and sodium chloride crystals are obtained.

[0029] The above description is a preferred embodiment of the present utility model, used to explain the technical solution of the present utility model, and is not intended to limit the present utility model. Those skilled in the art can make conventional modifications, equivalent substitutions and improvements within the spirit and principles of the present utility model, all of which are still included within the protection scope of the present utility model.

Claims

1. An energy-saving and efficient evaporation system for wastewater from nitrogen trifluoride production, characterized in that, include: A potassium fluoride waste liquid treatment unit includes a potassium fluoride waste liquid tank, a first booster pump, and a first pH adjustment tank connected in sequence by pipelines. A sodium sulfate waste liquid treatment unit includes a sodium sulfate waste liquid tank, a second booster pump, and a second pH adjustment tank connected in sequence by pipelines. A calcium chloride waste liquid treatment unit includes a calcium chloride waste liquid tank, a third lift pump, and a third pH adjustment tank connected in sequence by pipelines. The saline waste liquid treatment unit includes a saline waste liquid tank, a fourth lift pump, and a fourth pH adjustment tank connected in sequence by pipelines. The crystallization evaporation separation unit includes a multi-effect evaporator and a centrifuge connected to each other by pipes. The liquid inlet of the multi-effect evaporator is connected to the first pH adjustment tank, the second pH adjustment tank, the third pH adjustment tank and the fourth pH adjustment tank, respectively. The crystallization collection unit includes a potassium fluoride crystal collection tank, a sodium sulfate crystal collection tank, a calcium chloride crystal collection tank, and a sodium chloride crystal collection tank. The potassium fluoride crystal collection tank, sodium sulfate crystal collection tank, calcium chloride crystal collection tank, and sodium chloride crystal collection tank are respectively connected to a centrifuge via pipelines.

2. The energy-saving and high-efficiency evaporation system for nitrogen trifluoride production wastewater according to claim 1, characterized in that: A first valve, a second valve, a third valve, and a fourth valve are respectively installed on each pipeline between the first pH adjustment tank, the second pH adjustment tank, the third pH adjustment tank, the fourth pH adjustment tank and the multi-effect evaporator.

3. The energy-saving and high-efficiency evaporation system for nitrogen trifluoride production wastewater according to claim 1, characterized in that: The centrifuge is connected to the potassium fluoride crystal collection tank, sodium sulfate crystal collection tank, calcium chloride crystal collection tank, and sodium chloride crystal collection tank by a fifth valve, a sixth valve, a seventh valve, and an eighth valve, respectively.

4. The energy-saving and high-efficiency evaporation system for nitrogen trifluoride production wastewater according to claim 1, characterized in that: The multi-effect evaporator is a triple-effect evaporator.

5. The energy-saving and high-efficiency evaporation system for nitrogen trifluoride production wastewater according to claim 1, characterized in that: It also includes a backwashing unit, which includes a backwash water inlet pipe and a backwash water outlet pipe. The inlet end of the backwash water inlet pipe is connected to a water source, the outlet end of the backwash water inlet pipe is connected to a centrifuge, the inlet end of the backwash water outlet pipe is connected to a multi-effect evaporator, and the outlet end of the backwash water outlet pipe is connected to a potassium fluoride waste liquid tank, a sodium sulfate waste liquid tank, a calcium chloride waste liquid tank, and a rich saline waste liquid tank through four branch pipes respectively. The four branch pipes are respectively equipped with a first backwash water outlet valve, a second backwash water outlet valve, a third backwash water outlet valve, and a fourth backwash water outlet valve.

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