A high-efficiency and harmless treatment process for high-salt wastewater

Abstract

The present invention relates to the technical field of high-salt waste liquid treatment, and discloses a high-efficiency high-salt waste liquid harmless treatment process, comprising the following treatment steps: preheating the waste liquid for storage, wherein the waste liquid is preheated and then sent to a liquid storage tank for storage; ultrasonic atomization is performed on the preheated waste liquid, and the hot waste liquid in the liquid storage tank is atomized into small droplets under the action of the ultrasonic atomization system; evaporation separation is performed, wherein the atomized small droplets are sent to a high-temperature gasification separation chamber to separate water vapor, organic waste gas, and salt; oxidation combustion is performed, wherein the water vapor and organic waste gas separated by gasification are sent to an oxidation combustion chamber for combustion; high-temperature carbonization is performed, wherein the salt separated in the gasification separation chamber is collected and sent to a pyrolysis carbonization furnace for high-temperature carbonization to obtain carbonized salt. The present invention can efficiently perform harmless treatment on high-salt waste liquid, and can effectively recover salt in the waste liquid and water resources that can be reused, thereby effectively saving energy consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of high-salt waste liquid treatment, in particular to a high-efficiency high-salt waste liquid harmless treatment process. Background Art

[0002] Concentrated salty wastewater from industries such as chemical, electronics, power, coking, printing and dyeing, pesticides, and pharmaceuticals, due to its high levels of toxic and hazardous substances, is typically treated as hazardous waste, with treatment costs reaching thousands of yuan per ton, placing a heavy financial burden on businesses. Therefore, efficiently and energy-efficiently treating this type of organic wastewater or waste salt has become a pressing challenge for the industry. Summary of the Invention

[0003] (1) Technical problems solved

[0004] In response to the deficiencies of the prior art, the present invention provides a high-efficiency, low-energy-consumption harmless treatment and recovery method for high-salt waste liquid, which solves the problem in the prior art of lack of high-efficiency, low-energy-consumption harmless treatment and recovery method for saline waste liquid.

[0005] (2) Technical solution

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] The invention discloses a high-efficiency harmless treatment process for high-salt waste liquid, comprising the following treatment steps: preheating the waste liquid for storage, wherein the preheated waste liquid is sent to a liquid storage tank for storage; ultrasonic atomization is performed on the preheated waste liquid, and the hot waste liquid in the liquid storage tank is atomized into small droplets under the action of the ultrasonic atomization system; evaporation separation is performed, wherein the atomized small droplets are sent to a high-temperature gasification separation chamber to separate water vapor, organic waste gas and salt; oxidation combustion is performed, wherein the water vapor and organic waste gas separated by gasification are sent to an oxidation combustion chamber for combustion; tail gas treatment is performed, wherein the tail gas after oxidation combustion in the oxidation combustion chamber is discharged into a tail gas post-treatment system; high-temperature carbonization is performed, wherein the salt separated in the gasification separation chamber is collected and sent to a pyrolysis carbonization furnace for high-temperature carbonization to obtain carbonized salt; and the carbonized salt is recycled and utilized, wherein the carbonized salt is sent to a dissolution and impurity removal filtration system for separation treatment.

[0008] Preferably, the waste liquid is sent to the graphite gas-liquid heat exchanger through a liquid replenishing pump to be preheated to 60-80°C, and then sent to a liquid storage tank for storage. The graphite gas-liquid heat exchanger performs heat exchange on the tail gas discharged after treatment in the oxidation combustion chamber.

[0009] Preferably, the gasification separation chamber is arranged directly below the oxidation combustion chamber, and the heat comes from the thermal radiation of the oxidation combustion chamber, and the ultrasonic atomization injection port on the gasification separation chamber is arranged below the oxidation combustion chamber.

[0010] Preferably, the oxidative combustion chamber adopts an RTO incinerator, and the gasified gas in the gasification separation chamber is sent to the RTO incinerator, stays for 2 to 3 seconds in a high temperature environment of 760°C to 850°C, and is discharged into the exhaust gas after-treatment system after heat storage through heat storage ceramics after oxidative combustion.

[0011] Preferably, the exhaust gas after-treatment system includes a graphite coating spray tower, a PP spray tower, a dry filter and an activated carbon adsorption bed. A high-voltage electrostatic device is arranged between the PP spray tower and the dry filter to electrostatically capture smoke.

[0012] Preferably, the exhaust gas treatment system processes the condensed wastewater generated by the exhaust gas and the wastewater generated by the cleaning overflow, which are sent to the regulating tank and the integrated treatment equipment for treatment and then discharged or recycled.

[0013] Preferably, the salt separated in the gasification separation chamber is collected and sent to a pyrolysis carbonization furnace for high-temperature carbonization. The carbonization time lasts for 2 to 3 hours, and the carbonization temperature is controlled at 600 to 800°C. For different salts, the carbonization temperature does not exceed the melting point of the salt. The volatile organic waste gas generated during the carbonization process is introduced into the oxidation combustion chamber together with the waste gas generated in the gasification separation chamber for oxidation treatment.

[0014] Preferably, the carbonized salt separated by carbonization is separated from fixed carbon and impurities by a dissolution and impurity removal system, and then concentrated, crystallized and dried to recover industrial salt. The separated fixed carbon and impurities are sent to a solid waste incinerator for treatment to obtain ash.

[0015] (3) Beneficial effects

[0016] The present invention has the following beneficial effects:

[0017] This high-efficiency high-salt waste liquid harmless treatment process, by providing ultrasonic atomization and evaporation separation steps, can atomize the preheated waste liquid, and then perform efficient solid-gas separation on the atomized mixed gas through a high-temperature gasification separation chamber; by providing oxidative combustion and tail gas treatment steps, the waste gas generated in the separation process can be oxidized and burned, and at the same time, the tail gas after oxidative combustion is discharged into the tail gas after-treatment system for treatment, so that the waste gas generated in the treatment process can be efficiently and harmlessly treated; by providing a high-temperature carbonization step, solid waste salt can be separated and the salt therein can be recovered by high-temperature carbonization, and the salt in the waste liquid can be effectively separated and recovered for reuse. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall process flow of the present invention. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] See also Figure 1 The present invention provides a technical solution: a high-efficiency high-salt waste liquid harmless treatment process, comprising the following treatment steps: preheating the waste liquid and storing it in a liquid storage tank; ultrasonically atomizing the preheated waste liquid, and the hot waste liquid in the liquid storage tank is atomized into small droplets under the action of the ultrasonic atomizing system; evaporation separation, the atomized small droplets are sent to a high-temperature gasification separation chamber to separate water vapor, organic waste gas and salt; oxidation combustion, the water vapor and organic waste gas separated by gasification are sent to an oxidation combustion chamber for combustion; exhaust gas treatment, the exhaust gas after oxidation combustion in the oxidation combustion chamber is discharged into an exhaust gas after-treatment system; high-temperature carbonization, the salt separated in the gasification separation chamber is collected and sent to a pyrolysis carbonization furnace for high-temperature carbonization to obtain carbonized salt; recycling and utilizing the carbonized salt, and the carbonized salt is sent to a dissolution and impurity removal filtration system for separation and treatment.

[0021] The present invention, by providing ultrasonic atomization and evaporation separation steps, can atomize the preheated waste liquid, and then perform efficient solid-gas separation on the atomized mixed gas through a high-temperature gasification separation chamber; by providing oxidative combustion and tail gas treatment steps, the waste gas generated in the separation process can be oxidized and burned, and at the same time, the tail gas after oxidative combustion is discharged into the tail gas post-treatment system for treatment, so that the waste gas generated in the treatment process can be efficiently and harmlessly treated; by providing a high-temperature carbonization step, solid waste salt can be separated and high-temperature carbonized to recover the salt therein, and the salt in the waste liquid can be effectively separated and recovered for reuse.

[0022] Reference Figure 1 As shown, in this embodiment, waste liquid is pumped into a graphite gas-liquid heat exchanger via a liquid replenishment pump, where it is preheated to 60-80°C. It is then transferred to a liquid storage tank for storage. The graphite gas-liquid heat exchanger performs heat exchange with the exhaust gas discharged from the oxidation combustion chamber after treatment. The exhaust gas from the oxidation combustion chamber contains a certain amount of heat, generally controlled within 150°C. To recover some of this heat, a graphite gas-liquid heat exchanger, installed after the oxidation combustion furnace, is used to preheat the waste liquid after heat exchange, significantly reducing system energy consumption.

[0023] Reference Figure 1As shown, in this embodiment, the gasification separation chamber is located directly below the oxidation combustion chamber, and the heat is generated by the thermal radiation from the oxidation combustion chamber. The ultrasonic atomization nozzle on the gasification separation chamber is located below the oxidation combustion chamber. The thermal radiation from the oxidation combustion chamber keeps the gasification separation chamber at a high temperature, effectively saving the energy consumption required to maintain the high temperature of the gasification separation chamber. At the same time, because the ultrasonic atomization nozzle is located below the oxygen combustion chamber, the risk of salt entering the oxidation combustion chamber is effectively eliminated.

[0024] In this embodiment, the oxidation combustion chamber utilizes an RTO incinerator. The gasified gas in the gasification separation chamber is fed into the RTO incinerator, where it remains in a high-temperature environment of 760°C to 850°C for 2-3 seconds. After oxidation combustion, it is stored in thermal storage ceramics and discharged into the exhaust gas aftertreatment system. The RTO incinerator, combined with the thermal storage ceramics for heat storage, facilitates the subsequent rapid preheating of the incoming air, allowing the entire incinerator to efficiently maintain the desired oxidation combustion temperature, effectively saving energy.

[0025] Reference Figure 1 As shown, in this embodiment, the exhaust gas aftertreatment system includes a graphite-coated spray tower, a polypropylene (PP) spray tower, a dry filter, and an activated carbon adsorption bed. A high-voltage electrostatic device is positioned between the PP spray tower and the dry filter to electrostatically capture smoke. The exhaust gas treated in the oxidation combustion chamber contains hydrogen chloride and other acidic substances. Therefore, after exiting the graphite gas-liquid heat exchanger, it first enters the graphite-coated spray tower for acid absorption. The acidic gases in the exhaust gas are fully neutralized and absorbed using sodium hydroxide solution. It is then directed to the PP spray tower for water washing. After washing, the exhaust gas is essentially neutral. To eliminate visual pollution, a high-voltage electrostatic device is introduced to electrostatically capture smoke (particulate matter and water mist). The gas then enters the dry filter for secondary gas-liquid separation. To prevent dioxins from chlorine-containing organic matter during the gas oxidation process, the separated gas enters the activated carbon adsorption bed for adsorption. It is finally discharged through an induced draft fan and chimney to meet emission standards. The exhaust gas emitted at this time has no irritating odor, there is no visible smoke in the chimney, and all pollutant emission indicators meet the corresponding indicator requirements of the "Comprehensive Emission Standards for Air Pollutants" Jiangsu Landmark DB32 / 4041-2021.

[0026] In this embodiment, the exhaust gas treatment system processes the condensate wastewater and the wastewater generated by the wash overflow, which is then fed into a regulating tank and integrated treatment equipment for treatment before being discharged or recycled. The condensate wastewater and wash overflow wastewater generated during the exhaust gas treatment process are treated in the regulating tank and integrated treatment equipment before meeting discharge standards and meeting the requirements of the Chemical Industry Water Pollutant Discharge Standard DB32 / 939-2020.

[0027] In this embodiment, the salt separated in the gasification separation chamber is collected and sent to a pyrolysis carbonization furnace for high-temperature carbonization. The carbonization time lasts for 2 to 3 hours, and the carbonization temperature is controlled to 600 to 800°C. For different salt types, the carbonization temperature does not exceed the melting point of the salt. The volatile organic waste gas generated during the carbonization process is introduced into the oxidation combustion chamber together with the waste gas generated by the gasification separation chamber for oxidation treatment. The carbonized salt is pneumatically conveyed to the dissolution tank for dissolution. The dissolved solution enters the multi-media filter to filter and remove impurities (fixed carbon and impurities). The impurity-removed solution enters the MVR evaporation system for evaporation, concentration and crystallization. It then enters the centrifuge to separate the white crystalline salt with a moisture content of approximately 5%. It is then introduced into the drying system to dry it to a moisture content of less than 1%. Finally, it is packaged to obtain snow-white and clean industrial salt.

[0028] In this embodiment, the carbonized salt separated by carbonization is separated from fixed carbon and impurities by a dissolution and impurity removal system, and then concentrated, crystallized and dried to obtain industrial salt. The separated fixed carbon and impurities are sent to a solid waste incinerator for treatment to obtain ash.

[0029] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include," "comprise," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations. The phrase "includes an element defined by..." does not exclude the presence of other identical elements in the process, method, article, or device that includes the element.

[0030] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency high-salt waste liquid harmless treatment process, characterized in that: The following processing steps are included: The waste liquid is preheated and stored, and the waste liquid is preheated and sent to the liquid storage tank for storage; The preheated waste liquid is ultrasonically atomized, and the hot waste liquid in the liquid storage tank is atomized into small droplets under the action of the ultrasonic atomization system; Evaporation separation: the atomized droplets are sent to the high-temperature gasification separation chamber to separate water vapor, organic waste gas and salt; Oxidation combustion: the water vapor and organic waste gas separated by gasification are sent to the oxidation combustion chamber for combustion; Tail gas treatment: the tail gas after oxidation combustion in the oxidation combustion chamber is discharged into the tail gas post-treatment system: the gasification separation chamber is arranged directly below the oxidation combustion chamber, and the heat comes from the thermal radiation of the oxidation combustion chamber. The ultrasonic atomization injection port on the gasification separation chamber is arranged below the oxidation combustion chamber; High-temperature carbonization: the salt separated in the gasification separation chamber is collected and sent to the pyrolysis carbonization furnace for high-temperature carbonization to obtain carbonized salt; The carbonized salt is recycled and sent to the dissolution and impurity removal filtration system for separation and treatment.

2. The high-efficiency high-salt waste liquid harmless treatment process according to claim 1, characterized in that: The waste liquid is sent to the graphite gas-liquid heat exchanger through the liquid replenishing pump to be preheated to 60-80°C, and then sent to the liquid storage tank for storage. The graphite gas-liquid heat exchanger performs heat exchange on the tail gas discharged after treatment in the oxidation combustion chamber.

3. The high-efficiency high-salt waste liquid harmless treatment process according to claim 1, characterized in that: The oxidation combustion chamber adopts an RTO incinerator, and the gasified gas in the gasification separation chamber is sent to the RTO incinerator, stays for 2 to 3 seconds in a high temperature environment of 760°C to 850°C, and is discharged into the exhaust gas after-treatment system after heat storage through heat storage ceramics after oxidation combustion.

4. The high-efficiency high-salt waste liquid harmless treatment process according to claim 2, characterized in that: The exhaust gas after-treatment system includes a graphite coating spray tower, a PP spray tower, a dry filter and an activated carbon adsorption bed. A high-voltage electrostatic device is arranged between the PP spray tower and the dry filter to electrostatically capture smoke.

5. The high-efficiency high-salt waste liquid harmless treatment process according to claim 4 is characterized in that: The tail gas treatment system processes the condensed wastewater generated by the tail gas and the wastewater generated by the cleaning overflow, which are sent to the regulating tank and the integrated treatment equipment for treatment and then discharged or recycled.

6. The high-efficiency high-salt waste liquid harmless treatment process according to claim 1, characterized in that: The salt separated in the gasification separation chamber is collected and sent to a pyrolysis carbonization furnace for high-temperature carbonization. The carbonization time lasts for 2 to 3 hours, and the carbonization temperature is controlled at 600 to 800°C. For different salts, the carbonization temperature does not exceed the melting point of the salt. The volatile organic waste gas generated during the carbonization process is introduced into the oxidation combustion chamber together with the waste gas generated in the gasification separation chamber for oxidation treatment.

7. The high-efficiency high-salt waste liquid harmless treatment process according to claim 6, characterized in that: The carbonized salt separated by carbonization is separated into fixed carbon and impurities by a dissolution and impurity removal system, and then concentrated, crystallized and dried to recover industrial salt. The separated fixed carbon and impurities are sent to a solid waste incinerator for treatment to obtain ash.

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