Recycling treatment system for wastewater containing ammonium chloride

Abstract

The utility model discloses an ammonium chloride-containing wastewater resourceful treatment system, which relates to the technical field of ammonium chloride-containing wastewater resourceful treatment and comprises a raw water heating part, a crystal separation part, a separation and purification part, a steam heating part, a process water cleaning part, a condensate water part and a pump mechanical seal cooling part, according to the utility model, steam is used as a heat source to heat wastewater containing ammonium chloride, the wastewater is continuously concentrated, ammonium chloride is separated out, more ammonium chloride is separated out after the concentrated solution is cooled, and solid ammonium chloride is obtained through centrifugal separation and can be reused; and the centrifuged mother liquor is conveyed into the wastewater collection pool for ammonium chloride purification operation again, and the wastewater after ammonium chloride purification can be directly discharged after reaching the standard.

Description

Technical Field

[0001] The utility model relates to the technical field of resource treatment of waste water containing ammonium chloride, in particular to a resource treatment system for waste water containing ammonium chloride. Background Art

[0002] In the process of some chemical production and smelting separation, a large amount of wastewater containing ammonium chloride is generated. Due to the presence of ammonia nitrogen and chloride ions in ammonium chloride wastewater, if the wastewater is discharged directly, it will cause serious pollution to the water body. Ammonia nitrogen consumes dissolved oxygen in the water body and accelerates the eutrophication process of the water body; moreover, ammonia nitrogen will also be transformed into nitrate nitrogen and nitrite nitrogen under the action of microorganisms in the water, which is toxic to the human body. In addition, the large-scale discharge of ammonium chloride will have an adverse effect on the chloride ion concentration and pH value of the soil.

[0003] In the prior art, there are also treatment processes for wastewater containing ammonium chloride, among which:

[0004] The traditional evaporation process for treating wastewater containing ammonium chloride consumes a lot of steam, which greatly increases the treatment cost. In addition, the ions in the wastewater containing ammonium chloride are seriously corrosive to metal equipment, which makes it very difficult to select equipment materials. The energy consumption for evaporating low-concentration ammonium chloride wastewater to the crystallization concentration is too high and economically unbearable. When a high-concentration ammonium chloride solution is evaporated at high temperature, the ammonium chloride will significantly reverse sublimate, making it even more difficult to treat.

[0005] Steam mechanical recompression technology is to convert electrical energy into thermal energy by compressing the secondary steam generated by the evaporator with a high-efficiency steam compressor. The secondary steam heat energy is transported to the evaporator after being increased, and further heated to generate secondary steam. During the treatment of ammonium chloride wastewater, a double-effect forced circulation evaporator is adopted, and the two effects are evaporated simultaneously, which can make full use of the secondary steam. This treatment method can reduce energy consumption on the one hand, and reduce the investment in the construction of heating facilities on the other hand. However, the ammonium chloride wastewater generated by the factory will contain different types of organic matter, and the content is large. During the evaporation and concentration, new organic matter may be generated due to the influence of different components in the ammonium chloride wastewater and surrounding factors. Moreover, since these organic molecules are often large in mass and high in boiling point, the evaporation temperature will continue to increase during the evaporation and concentration.

[0006] Electrodialysis technology is used to treat ammonium chloride-containing wastewater: under the action of a DC electric field, the driving force generated by the potential difference is used to separate the electrolyte from the solution based on the selective permeability of the ion exchange membrane, thereby completing the treatment of the solution, achieving solution desalination and refinement, and then completing the treatment of ammonium chloride wastewater. It should be noted that when using electrodialysis technology to treat ammonium chloride wastewater, it is difficult to accurately grasp the various parameters during the treatment period, and it is difficult to control. Unreasonable parameter control will affect the treatment effect.

[0007] Reverse osmosis membrane technology has been widely used in the treatment of industrial wastewater, preparation of pure water, desalination of seawater and other aspects. When ammonium chloride wastewater is treated with reverse osmosis membrane technology, under the same operating time, as the operating pressure increases, the desalination rate of ammonium chloride wastewater will increase, and the water production rate will increase. However, during the actual treatment period, the water production rate will change to a large extent, with the lowest water production rate being only 8.88% and the highest water production rate being 40.33%. If the concentration of ammonium chloride is low, higher economic benefits can be achieved. If the concentration is high, reverse osmosis membrane technology is used for treatment, but due to the large energy consumption and high cost, the application effect is relatively poor and it is not suitable for use. Moreover, after the reverse osmosis membrane components are put into use, they will be contaminated and difficult to rinse after long-term operation.

[0008] Application number: CN202022757842.5, a treatment system for high-organic and high-ammonium chloride wastewater, includes a pretreatment mechanism, a UV-AOP ultraviolet oxidation mechanism, a crystallization mechanism, and an exhaust gas treatment mechanism. The output end of the pretreatment mechanism is connected to the input end of the UV-AOP ultraviolet oxidation mechanism, and the output end of the UV-AOP ultraviolet oxidation mechanism is connected to the input end of the crystallization mechanism; although the application can extract and separate ammonium chloride for the treatment of ammonium chloride-containing wastewater, other reagents need to be added in the process of extraction and separation to complete it, which will bring difficulties to subsequent wastewater treatment and increase treatment costs. Utility Model Content

[0009] The utility model aims to provide a resource treatment system for ammonium chloride-containing wastewater, so as to solve the problem that the existing ammonium chloride-containing wastewater mentioned in the above background technology needs to add other reagents in the process of extracting ammonium chloride, which will bring difficulties to the subsequent wastewater treatment and increase the treatment cost.

[0010] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a resource treatment system for ammonium chloride-containing wastewater, comprising a raw water heating part, a crystallization separation part and a separation and purification part connected in sequence through pipelines; the raw water heating part and the crystallization separation part are commonly connected to a steam heating part and a condensed water part through pipelines; the crystallization separation part is also connected to a process water cleaning part through pipelines; a wastewater collection tank is arranged at the front end of the raw water heating part and is connected to a wastewater feed pump through pipelines and valves, and the outlet end of the wastewater feed pump is sequentially connected to a first preheater, a second preheater, a first preheater and a second preheater through pipelines. a forced circulation heater and a second forced circulation heater; the crystallization separation part comprises a crystallization separator and the upper air outlet of the crystallization separator is sequentially connected to a washing tower, a steam compressor and a volute drainage tank through a pipeline, and the bottom end is connected to a separation and purification part through a pipeline; the separation and purification part comprises two cooling tanks arranged in parallel and connected to the crystallization separator through a pipeline, the discharge ports of the two cooling tanks are connected to a centrifuge through a pipeline, the liquid outlet of the centrifuge is connected to a mother liquid tank through a pipeline and then to a mother liquid pump, and the outlet end of the mother liquid pump is connected to a wastewater collection pool through a pipeline.

[0011] Preferably, the first forced circulation heater and the second forced circulation heater are both vertically arranged shell and tube heat exchangers, and the top end of the first forced circulation heater is connected to the outlet of the second preheater, and the bottom end is connected to the bottom end of the second forced circulation heater through a pipeline and a forced circulation pump, and the top end of the second forced circulation heater is connected to the crystallization separator through a pipeline.

[0012] Preferably, the bottom end of the washing tower is connected to a washing pump through a pipeline, and the outlet end of the washing pump is connected to a multi-layer washing spray layer arranged on the upper part of the crystallization separator through a pipeline; the gas outlet of the steam compressor is connected to the steam inlet of the second forced circulation heater through a pipeline.

[0013] Preferably, cooling water is passed through the side walls of the two cooling tanks, and a stirrer is provided at the top.

[0014] Preferably, the steam heating part is connected to the steam source through a pipeline, and is respectively connected to the second preheater, the first forced circulation heater, the second forced circulation heater and the steam compressor through pipelines; the steam outlets of the first forced circulation heater and the second forced circulation heater are connected to the steam inlet of the second preheater through pipelines, and the steam outlet of the second preheater is connected to the vacuum system part through a pipeline.

[0015] Preferably, the process water cleaning part is connected to the process water supply pipe through a pipeline, and is respectively connected to the crystallizer separator and the washing tower through pipelines, and a spray structure is provided on the top and side wall of the crystallizer, and is connected to the interior of the washing tower near the lower end of the side wall.

[0016] Preferably, the condensate water part includes a volute drainage pump, a condensate water tank, and a condensate water pump which are sequentially connected to the volute drainage tank through pipelines, and the outlet end of the condensate water pump is connected to the first preheater through a pipeline; the water inlet end of the condensate water tank is respectively connected to the first forced circulation heater and the second forced circulation heater through pipelines, and the air outlet end is sequentially connected to the overheating elimination pump and the steam compressor through pipelines.

[0017] Preferably, the forced circulation pump, the discharge pump, the volute drainage pump, the condensate pump, and the overheat elimination pump are respectively connected to a pump seal cooling part through pipelines.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] The utility model adopts steam as a heat source to heat the waste water containing ammonium chloride, continuously concentrates the waste water and precipitates the ammonium chloride, the concentrated solution precipitates more ammonium chloride after cooling, and the solid ammonium chloride is obtained by centrifugal separation and can be reused, and the mother liquor after centrifugation is transported to the waste water collection pool for re-purification of ammonium chloride, and the waste water after the ammonium chloride is purified can meet the standards and be directly discharged. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a flow chart;

[0021] Figure 2 It is a schematic diagram of the process structure;

[0022] In the figure: raw water heating section -1, wastewater feed pump -11, first preheater -12, second preheater -13, first forced circulation heater -14, second forced circulation heater -15, forced circulation pump -16, crystallization separation section -2, crystallization separator -21, washing tower -22, washing pump -23, steam compressor -24, volute drainage tank -25, discharge pump -26, separation and purification section -3, cooling tank -31, centrifuge -32, mother liquor tank -33, mother liquor pump -34, steam heating section -4, vacuum system section -41, process water cleaning section -5, condensate water section -6, volute drainage pump -61, condensate water tank -62, condensate water pump -63, overheat elimination pump -64, pump machine seal cooling section -7. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the technical solution of the present utility model, the technical solution in the embodiments of the present utility model is clearly and completely described below in conjunction with the accompanying drawings and specific embodiments.

[0024] The utility model provides a resource treatment system for ammonium chloride-containing wastewater, which is used for extracting ammonium chloride from ammonium chloride-containing wastewater for resource recycling, and discharging the treated wastewater in compliance with standards; it comprises a raw water heating part 1 for heating the ammonium chloride-containing wastewater to be treated, the ammonium chloride-containing wastewater preheated in the raw water heating part 1 enters a crystal separation part 2 through a pipeline for crystallization separation, the gas part after crystallization separation is washed and then re-enters the raw water heating part 1 through a pipeline for use as a heat source, and the turbid liquid containing ammonium chloride crystal particles after crystallization separation is transported to a separation and purification part 3 through a pipeline to extract ammonium chloride and utilize it as a resource; the raw water heating part 1 is also connected to a steam heating part 4, which uses steam as a heat source to heat the ammonium chloride-containing wastewater to be treated; the crystal separation part 2 is connected to a process water cleaning part 5, which is used for cleaning the gas after crystallization separation; the raw water heating part 1 and the crystal separation part 2 are also commonly connected to a condensed water part 6, which is used for collecting the condensed water after condensation and recycling it.

[0025] A wastewater collection pool is provided at the front end of the raw water heating unit 1, which is used to collect the ammonium chloride-containing wastewater in the factory area into the wastewater collection pool through underground pipes and culverts, and the wastewater collection pool is connected to a wastewater feed pump 11 through pipes and valves for transporting the ammonium chloride-containing wastewater, and the outlet end of the wastewater feed pump 11 is connected to a first preheater 12 through a pipe for preliminarily preheating the ammonium chloride-containing wastewater, and the outlet end of the first preheater 12 is connected to a second preheater 13 through a pipe, and the ammonium chloride-containing wastewater that is reheated in the second preheater 13 is transported to a first forced circulation heater 14 through a pipe, and the ammonium chloride-containing wastewater that is once forcedly heated in the first forced circulation heater 14 is transported to a second forced circulation heater 15 through a pipe for reheating, and the heated ammonium chloride wastewater is transported to the crystallization separation unit 2 through a pipe for crystallization separation operation.

[0026] The first preheater 12 is also connected to the condensed water part 6 through a pipeline. The condensed water after condensation and collection has a higher water temperature than the wastewater in the wastewater collection pool. The first preheater 12 preliminarily heats the ammonium chloride-containing wastewater after heat exchange.

[0027] The second preheater 13 is also connected to the steam heating unit 4 through a pipeline. The steam in the steam heating unit 4 is transported to the second preheater 13 through a pipeline after heating the first forced circulation heater 14 and the second forced circulation heater 15, so as to reheat the ammonium chloride-containing wastewater that has been preliminarily preheated.

[0028] The first forced circulation heater 14 and the second forced circulation heater 15 are both vertically arranged shell and tube heat exchangers, and the top end of the first forced circulation heater 14 is connected to the outlet of the second preheater 13, and the bottom end is connected to the bottom end of the second forced circulation heater 15 through a pipeline and a forced circulation pump 16, the top end of the second forced circulation heater 15 is connected to the crystallization separation part 2 through a pipeline, and the inlet near the upper end on the side wall of the first forced circulation heater 14 and the second forced circulation heater 15 is connected to the steam heating part 4 through a pipeline.

[0029] The crystal separation part 2 includes a vertically arranged crystal separator 21, a feed port near the lower end on the side wall of the crystal separator 21 is connected to the outlet end of the second forced circulation heater 15 through a pipeline, and a gas outlet near the top is connected to a washing tower 22 through a pipeline, the top and side walls of the crystal separator 21 are connected to the process water cleaning part 5 through a pipeline, which is used to spray process water into the crystal separator 21, and the bottom end of the crystal separator 21 is connected to the separation and purification part 3 through a pipeline; the side wall of the washing tower 22 is connected to the process water cleaning part 5 through a pipeline near the lower end for replenishing process water used for washing, and the bottom end of the washing tower 22 is connected to a washing pump 23 through a pipeline, and the outlet end of the washing pump 23 is connected to the washing tower 22 through a pipeline. A multi-layer washing spray layer arranged on the upper part of the crystal separator 21 is connected; an air outlet is arranged on the side wall of the washing tower 22 above the process water inlet and is connected to a steam compressor 24 through a pipeline, and the steam compressor 24 is also connected to the steam heating part 4 through a pipeline, so that the gas and steam discharged from the washing tower 22 are compressed together, and the compressed liquid directly enters the volute drainage tank 25 through a pipeline for temporary storage, and the gas after compression and removal is transported to the second forced circulation heater 15 through a pipeline for forced heating together with the steam provided by the steam heating part 4; the bottom discharge port of the crystal separator 21 is connected to a discharge pump 26 through a pipeline, and the outlet end of the discharge pump 26 is connected to the separation and purification part 3 through a pipeline.

[0030] The separation and purification section 3 includes two cooling tanks 31 arranged in parallel, and cooling water is passed through the side walls of the two cooling tanks 31 for cooling the materials in the cooling tanks 31, and the materials in the tanks are always stirred by the agitator arranged at the top during the cooling process, so as to ensure that the materials can be cooled quickly, and as the cooling proceeds, more ammonium chloride can be precipitated from the solution, and then the solution containing the precipitated ammonium chloride is transported to the centrifuge 32 through the pipeline at the bottom of the cooling tank 31 for centrifugal separation, and the mother liquor separated by the centrifuge 32 is transported to the mother liquor tank 33 through the pipeline for temporary storage, and the mother liquor tank 33 is connected to the mother liquor pump 34 through the pipeline, and the mother liquor temporarily stored in the mother liquor tank 33 is transported to the wastewater collection pool for re-treatment by the mother liquor pump 34; the ammonium chloride solid separated by the centrifuge 32 can be reused as a raw material.

[0031] The steam heating part 4 is connected to the steam source through a pipeline, and the steam is transported to the second preheater 13, the first forced circulation heater 14, the second forced circulation heater 15 and the steam compressor 24 through the pipeline for steam heating; the steam after heat exchange in the first forced circulation heater 14 and the second forced circulation heater 15 is transported to the second preheater 13 through a pipeline for heat exchange operation, and the steam after heat exchange is transported to the vacuum system part 41 through a pipeline, and is discharged after being cooled by cooling water in the vacuum system 41.

[0032] The process water cleaning section 5 is connected to the process water supply pipe through a pipeline, and transports the process water to the crystal separator 21 and the washing tower 22 through the pipeline for use as washing water.

[0033] The condensate part 6 includes a volute drainage pump 61 connected to the volute drainage tank 25 through a pipeline, and the compressed liquid temporarily stored in the volute drainage tank 25 is transported to the condensate tank 62 through the volute drainage pump 61. The bottom end of the condensate tank 62 is connected to a condensate pump 63 through a pipeline, and the condensate in the condensate tank 62 is transported to the first preheater 12 through the condensate pump 63 for preliminary preheating of the ammonium chloride-containing wastewater. The condensate after preheating and cooling is discharged through the pipeline for reuse; the water inlet end of the condensate tank 62 is connected to the first forced circulation heater 14 and the second forced circulation heater 15 through pipelines, and the condensate after heat exchange of the steam is transported to the condensate tank 62 through the pipeline for temporary storage; the condensate tank 62 is also connected to an overheating elimination pump 64 through a pipeline, which is used to transport the steam in the condensate tank 62 to the steam compressor for treatment.

[0034] In addition, the forced circulation pump 16, the discharge pump 26, the volute drainage pump 61, the condensate pump 63, and the overheat elimination pump 64 are respectively connected to the pump seal cooling part 7 through pipelines for cooling the corresponding pump seals.

[0035] The utility model adopts steam as a heat source to heat the waste water containing ammonium chloride, continuously concentrates the waste water and precipitates the ammonium chloride, the concentrated solution precipitates more ammonium chloride after cooling, and the solid ammonium chloride is obtained by centrifugal separation and can be reused, and the mother liquor after centrifugation is transported to the waste water collection pool for re-purification of ammonium chloride, and the waste water after the ammonium chloride is purified can meet the standards and be directly discharged.

[0036] Although the embodiments of the utility model have been shown and described, it is obvious that the described embodiments are only a part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, it can be understood by ordinary technicians in this field that all other embodiments obtained by making various changes, modifications, substitutions and variations to these embodiments without departing from the principle and spirit of the utility model and without making creative work, all belong to the scope of protection of the utility model.

Claims

1. A system for recycling wastewater containing ammonium chloride, characterized in that: The invention comprises a raw water heating section (1), a crystal separation section (2) and a separation and purification section (3) which are connected in sequence through pipelines; the raw water heating section (1) and the crystal separation section (2) are connected to a steam heating section (4) and a condensed water section (6) through pipelines; the crystal separation section (2) is also connected to a process water cleaning section (5) through pipelines; a wastewater collection tank is arranged at the front end of the raw water heating section (1) and is connected to a wastewater feed pump (11) through pipelines and valves; the outlet end of the wastewater feed pump (11) is connected to a first preheater (12), a second preheater (13), a first forced circulation heater (14) and a second forced circulation heater (15) in sequence through pipelines; The crystallization separation section (2) comprises a crystallization separator (21) and the upper gas outlet of the crystallization separator is connected in sequence to a washing tower (22), a steam compressor (24) and a volute drainage tank (25) through a pipeline, and the bottom end is connected to a separation and purification section (3) through a pipeline; the separation and purification section (3) comprises two cooling tanks (31) arranged in parallel and connected to the crystallization separator (21) through a pipeline, the discharge ports of the two cooling tanks (31) are connected to a centrifuge (32) through a pipeline, the liquid outlet of the centrifuge (32) is connected to a mother liquid tank (33) through a pipeline and then connected to a mother liquid pump (34), and the outlet end of the mother liquid pump (34) is connected to a wastewater collection tank through a pipeline.

2. The ammonium chloride-containing wastewater resource treatment system according to claim 1, characterized in that: The first forced circulation heater (14) and the second forced circulation heater (15) are both vertically arranged shell and tube heat exchangers, and the top end of the first forced circulation heater (14) is connected to the outlet of the second preheater (13), and the bottom end is connected to the bottom end of the second forced circulation heater (15) through a pipeline and a forced circulation pump (16), and the top end of the second forced circulation heater (15) is connected to the crystallization separator (21) through a pipeline.

3. The ammonium chloride-containing wastewater resource treatment system according to claim 2, characterized in that: The bottom end of the washing tower (22) is connected to a washing pump (23) via a pipeline, and the outlet end of the washing pump (23) is connected to a multi-layer washing spray layer arranged on the upper part of the crystallization separator (21) via a pipeline; the gas outlet of the steam compressor (24) is connected to the steam inlet of the second forced circulation heater (15) via a pipeline.

4. The ammonium chloride-containing wastewater resource treatment system according to claim 3, characterized in that: Cooling water is passed through the side walls of the two cooling tanks (31), and a stirrer is arranged at the top.

5. The ammonium chloride-containing wastewater resource treatment system according to claim 4, characterized in that: The steam heating unit (4) is connected to a steam source via a pipeline, and is respectively connected to a second preheater (13), a first forced circulation heater (14), a second forced circulation heater (15) and a steam compressor (24) via pipelines; the steam outlets of the first forced circulation heater (14) and the second forced circulation heater (15) are connected to the steam inlet of the second preheater (13) via pipelines, and the steam outlet of the second preheater (13) is connected to a vacuum system unit (41) via a pipeline.

6. The ammonium chloride-containing wastewater resource treatment system according to claim 5, characterized in that: The process water cleaning section (5) is connected to the process water supply pipe through a pipeline, and is respectively connected to the crystal separator (21) and the washing tower (22) through pipelines, and a spray structure is provided on the top and side wall of the crystal separator (21), and is connected to the inside of the washing tower (22) near the lower end of the side wall.

7. The ammonium chloride-containing wastewater resource treatment system according to claim 6, characterized in that: The condensate water section (6) comprises a volute drainage pump (61), a condensate water tank (62), and a condensate water pump (63) which are sequentially connected to the volute drainage tank (25) via pipelines; the outlet end of the condensate water pump (63) is connected to the first preheater (12) via a pipeline; the water inlet end of the condensate water tank (62) is respectively connected to the first forced circulation heater (14) and the second forced circulation heater (15) via pipelines, and the air outlet end is sequentially connected to the overheat elimination pump (64) and the steam compressor via pipelines.

8. The ammonium chloride-containing wastewater resource treatment system according to claim 7, characterized in that: The forced circulation pump (16), the discharge pump (26), the volute drainage pump (61), the condensate pump (63), and the overheat elimination pump (64) are respectively connected to a pump seal cooling part (7) through pipelines.

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