Boiler wastewater recycling device

Abstract

The utility model discloses a boiler wastewater recycling device which consists of a pretreatment unit, a deep desalting unit, a concentration and concentration unit and a quality-divided crystallization unit which are connected in sequence. Compared with the prior art, the device disclosed by the utility model has the advantages that a plurality of treatment units such as pretreatment, deep desalting, concentration and concentration, quality-divided crystallization and the like are integrated, and are connected through reasonable pipelines, so that the occupied area of equipment is reduced, and the device is convenient to install and maintain.

Description

Technical Field

[0001] This utility model relates to the field of industrial wastewater treatment technology, specifically a boiler wastewater recycling device. Background Technology

[0002] In industrial production, boiler wastewater contains large amounts of suspended solids, salts, and harmful substances. Direct discharge not only wastes water resources but also causes environmental pollution. Existing boiler wastewater treatment devices suffer from problems such as complex treatment processes, low equipment integration, poor salt resource recovery, and high energy consumption. For example, traditional treatment devices have relatively independent treatment units with insufficient compact connections, resulting in a large footprint; during salt recovery, the fractional crystallization effect is poor, the impurity salt rate is high, and the resource utilization rate is low; at the same time, there is a lack of effective linkage control between devices, making it difficult to adjust treatment parameters in real time according to changes in water quality, affecting treatment efficiency and effectiveness. Therefore, there is an urgent need to design a boiler wastewater recycling device that is compact in structure, functionally integrated, has good salt resource recovery effect, and low energy consumption.

[0003] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the above-mentioned technical defects and provide a boiler wastewater recycling device.

[0005] To solve the above problems, the technical solution of this utility model is: a boiler wastewater recycling device, characterized in that: it includes a pretreatment unit, a deep desalination unit, a concentration and enrichment unit and a fractional crystallization unit connected in sequence;

[0006] The pretreatment unit includes a bar screen, a grit chamber, an equalization tank, a cooling tower, an air flotation machine, and a sedimentation tank connected in sequence.

[0007] The deep desalination unit includes a nanofiltration membrane module and an ion exchange column, wherein the nanofiltration membrane module and the ion exchange column are connected in series.

[0008] The concentration and enrichment unit includes a high-pressure RO membrane and an MVR evaporator, with the concentrate outlet of the high-pressure RO membrane connected to the feed inlet of the MVR evaporator.

[0009] The fractional crystallization unit includes a forced circulation evaporator, an OSLO crystallizer, and a frozen crystallization tank. The outlet of the MVR evaporator is connected to the inlet of the forced circulation evaporator, and the outlet of the forced circulation evaporator is connected to both the OSLO crystallizer and the frozen crystallization tank.

[0010] Furthermore, the regulating tank is equipped with a stirrer and a level gauge, the air flotation machine is a dissolved air flotation machine, and the sedimentation tank is an inclined tube sedimentation tank.

[0011] Furthermore, a PLC control system is also provided. The PLC control system is electrically connected to the bar screen, agitator, level gauge, flotation machine, high-pressure pump, steam compressor of MVR evaporator, circulation pump of forced circulation evaporator, and refrigeration unit of frozen crystallizer. The system monitors water quality data in real time through online conductivity, pH, and density sensors, and automatically adjusts the operating parameters of each device according to the data.

[0012] Furthermore, the fractional crystallization unit has a mother liquor circulation pipe at one end of the mother liquor outlet and the other end is connected to the feed inlet of the concentration and enrichment unit.

[0013] Furthermore, the miscellaneous salt outlet of the fractional crystallization unit is equipped with a miscellaneous salt treatment device.

[0014] Furthermore, the nanofiltration membrane module is used for salt separation, achieving the separation of Cl- and SO4. 2 The separation process includes: the ion exchange column for removing calcium and magnesium ions; the high-pressure RO membrane for highly concentrating the concentrated water after deep desalination; the MVR evaporator for evaporating and concentrating the concentrated water from the high-pressure RO membrane using steam circulation; the forced circulation evaporator for evaporating and crystallizing the solution concentrated by the MVR evaporator; the OSLO crystallizer for producing large-particle crystals; and the cryogenic crystallizer for precipitating sodium sulfate at low temperatures.

[0015] The advantages of this invention compared to existing technologies are as follows: This invention integrates multiple treatment units such as pretreatment, deep desalination, concentration and fractional crystallization. The units are connected by reasonable pipelines, which reduces the equipment footprint and facilitates installation and maintenance. By combining multiple technologies such as nanofiltration membrane salt separation, forced circulation evaporation, and freeze crystallization, it achieves efficient separation and crystallization recovery of salts, improving resource utilization. The device can flexibly adjust the operating parameters of each treatment unit according to the different water qualities of boiler wastewater through the PLC system, so as to achieve effective treatment of wastewater with different salt contents and different pollutant compositions. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating the process of this utility model. Figure 1 .

[0017] Figure 2 This is a flowchart illustrating the process of this utility model. Figure 2 .

[0018] As shown in the figure: 1. Pretreatment unit; 101. Bar screen; 102. Grit chamber; 103. Equalization tank; 104. Cooling tower; 105. Air flotation unit; 106. Sedimentation tank; 2. Deep desalination unit; 201. Nanofiltration membrane module; 202. Ion exchange column; 3. Concentration and enrichment unit; 301. High-pressure RO membrane; 302. MVR evaporator; 4. Separate crystallization unit; 401. Forced circulation evaporator; 402. OSLO crystallizer; 403. Freezing crystallizer. Detailed Implementation

[0019] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings. Identical components are indicated by the same reference numerals.

[0020] It should be noted that the terms “front,” “back,” “left,” “right,” “up,” and “down” used in the following description refer to the directions shown in the attached diagram, while the terms “inside” and “outside” refer to the directions toward or away from the geometric center of a specific component, respectively.

[0021] To make the content of this utility model easier to understand, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0022] like Figures 1 to 2 As shown, a boiler wastewater recycling device consists of a pretreatment unit 1, a deep desalination unit 2, a concentration and enrichment unit 3, and a fractional crystallization unit 4 connected in sequence.

[0023] The pretreatment unit 1 includes a screen 101, a grit chamber 102, an equalization tank 103, a cooling tower 104, an air flotation machine 105, and a sedimentation tank 106 connected in sequence. The equalization tank 103 is equipped with a stirrer and a level gauge. The air flotation machine 105 is a dissolved air flotation machine 105. The sedimentation tank 106 is an inclined tube sedimentation tank 106. Boiler wastewater is first transported to the pretreatment unit 1 through pipelines. It passes through the screen 101 to remove large particulate impurities, enters the grit chamber 102 to settle sand particles, and is stirred and balanced in the equalization tank 103 by the stirrer. After the water level is monitored by the level gauge, the wastewater flows into the cooling tower 104 to cool down, then enters the dissolved air flotation machine 105 to remove grease and colloids, and finally the sediment is separated in the inclined tube sedimentation tank 106.

[0024] The deep desalination unit 2 includes a nanofiltration membrane module 201 and an ion exchange column 202 connected in series. Pretreated wastewater enters the deep desalination unit 2, where it first passes through the nanofiltration membrane module 201 for salt separation, achieving the separation of Cl- and SO42-. 2 - Initial separation, then enters ion exchange column 202 to remove calcium and magnesium ions.

[0025] The concentration and enrichment unit 3 includes a high-pressure RO membrane 301 and an MVR evaporator 302. The concentrate outlet of the high-pressure RO membrane 301 is connected to the feed inlet of the MVR evaporator 302. The concentrate after deep desalination enters the concentration and enrichment unit 3 and is highly concentrated through the high-pressure RO membrane 301. The concentrate outlet of the high-pressure RO membrane 301 is connected to the feed inlet of the MVR evaporator 302. The MVR evaporator 302 uses steam circulation to evaporate and concentrate the concentrate.

[0026] The fractional crystallization unit 4 includes a forced circulation evaporator 401, an OSLO crystallizer 402, and a frozen crystallizer 403. The outlet of the MVR evaporator 302 is connected to the inlet of the forced circulation evaporator 401. The outlet of the forced circulation evaporator 401 is connected to both the OSLO crystallizer 402 and the frozen crystallizer 403. A mother liquor circulation pipe is provided at one end of the fractional crystallization unit 4, and the other end is connected to the inlet of the concentration and enrichment unit 3. A miscellaneous salt treatment device is provided at the miscellaneous salt outlet of the fractional crystallization unit 4. A nanofiltration membrane module 201 is used for salt separation to separate Cl- and SO4. 2 The separation process involves ion exchange column 202 for removing calcium and magnesium ions, high-pressure RO membrane 301 for high-concentration of the concentrated water after deep desalination, MVR evaporator 302 for evaporating and concentrating the concentrated water from high-pressure RO membrane 301 using steam circulation, forced circulation evaporator 401 for evaporating and crystallizing the solution concentrated by MVR evaporator 302, OSLO crystallizer 402 for producing large-particle crystals, and cryogenic crystallizer 403 for precipitating sodium sulfate at low temperature. The solution concentrated by MVR evaporator enters fractional crystallization unit 4, first entering forced circulation evaporator 401 for evaporation and crystallization, and then, according to the salt composition and processing requirements, the solution is respectively sent to OSLO crystallizer to produce large-particle crystals or cryogenic crystallizer 403 for low-temperature crystallization to precipitate sodium sulfate.

[0027] It also includes a PLC control system, which is electrically connected to the bar screen 101, agitator, level gauge, flotation machine 105, high-pressure pump, steam compressor of MVR evaporator 302, circulation pump of forced circulation evaporator 401, and refrigeration unit of freezing crystallizer 403. The system monitors water quality data in real time using online conductivity, pH, and density sensors, and automatically adjusts the operating parameters of each device based on the data. Throughout the treatment process, the PLC control system monitors water quality data in real time using online conductivity, pH, and density sensors, and automatically adjusts the bar screen 101 based on the data. The operating parameters of equipment such as agitator, flotation machine 105, high-pressure pump, steam compressor, circulating pump, and refrigeration unit are specified. The mother liquor generated during the crystallization process is returned to the concentration and enrichment unit 3 for recycling through the mother liquor circulation pipeline. The miscellaneous salts are spray-dried or mixed with building material raw materials for co-processing through the miscellaneous salt treatment device. After treatment by the boiler wastewater recycling device of this utility model, the salt recovery rate of the factory's boiler wastewater reaches 88%, the water resource recovery rate is significantly improved, the energy consumption is reduced by 40%, and the amount of miscellaneous salts discharged is reduced, realizing the efficient recycling and resource treatment of boiler wastewater.

[0028] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0029] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

[0030] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A boiler wastewater recycling device, characterized in that: It includes a pretreatment unit (1), a deep desalination unit (2), a concentration and enrichment unit (3), and a fractional crystallization unit (4) connected in sequence; The pretreatment unit (1) includes a screen (101), a grit chamber (102), an equalization tank (103), a cooling tower (104), an air flotation machine (105), and a sedimentation tank (106) connected in sequence; The deep desalination unit (2) includes a nanofiltration membrane module (201) and an ion exchange column (202), wherein the nanofiltration membrane module (201) and the ion exchange column (202) are connected in series. The concentration and enrichment unit (3) includes a high-pressure RO membrane (301) and an MVR evaporator (302), with the concentrate outlet of the high-pressure RO membrane (301) connected to the feed inlet of the MVR evaporator (302). The fractional crystallization unit (4) includes a forced circulation evaporator (401), an OSLO crystallizer (402), and a frozen crystallizer (403). The outlet of the MVR evaporator (302) is connected to the inlet of the forced circulation evaporator (401), and the outlet of the forced circulation evaporator (401) is connected to the OSLO crystallizer (402) and the frozen crystallizer (403) respectively.

2. The boiler wastewater recycling device according to claim 1, characterized in that: The regulating tank (103) is equipped with a stirrer and a level gauge. The air flotation machine (105) is a dissolved air flotation machine (105). The sedimentation tank (106) is an inclined tube sedimentation tank (106).

3. The boiler wastewater recycling device according to claim 1, characterized in that: It is also equipped with a PLC control system, which is electrically connected to the bar screen (101), agitator, level gauge, air flotation machine (105), high pressure pump, steam compressor of MVR evaporator (302), circulation pump of forced circulation evaporator (401), and refrigeration unit of frozen crystallizer (403). The PLC control system monitors water quality data in real time through online conductivity, pH and density sensors, and automatically adjusts the operating parameters of each device according to the data.

4. The boiler wastewater recycling device according to claim 1, characterized in that: The fractional crystallization unit (4) has a mother liquor circulation pipe at one end of the mother liquor outlet and the other end is connected to the feed inlet of the concentration and enrichment unit (3).

5. A boiler wastewater recycling device according to claim 1, characterized in that: The miscellaneous salt outlet of the fractional crystallization unit (4) is equipped with a miscellaneous salt treatment device.

6. The boiler wastewater recycling device according to claim 1, characterized in that: The nanofiltration membrane module (201) is used for salt separation, achieving the separation of Cl- and SO4. 2 The separation of calcium and magnesium ions is achieved by the ion exchange column (202), the high-pressure RO membrane (301), the MVR evaporator (302), the forced circulation evaporator (401), the OSLO crystallizer (402), and the cryogenic crystallizer (403).

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