阅读说明：本技术 一种固定床煤气油尘干式协同净化及间接冷却的装置和方法 (Device and method for dry type cooperative purification and indirect cooling of coal gas and oil dust of fixed bed ) 是由 阳绍军 刘璐 莫国强 陈武 李正林 于 2020-06-11 设计创作，主要内容包括：本发明提供了一种固定床煤气油尘干式协同净化及间接冷却的装置和方法,属于煤气处理技术领域。本发明提供的装置整体结构设置合理,煤气净化效果好,节能环保。具体的,采用油尘预脱除装置1、干式除尘器2及间接冷却器3,煤气中的粉尘及焦油可以被高效协同净化分离,煤气冷凝液中杂质含量低,因此可以解决传统煤气化直接冷却工艺存在的含油、含酚、含尘废水污染及难处理问题；而且采用油尘预脱除装置1及干式除尘器2,粉尘及焦油分离效率高,因此可以解决煤气中所含焦油对除尘系统的粘附堵塞问题；采用间接冷却器3及汽提蒸氨系统4,脱除氨氮后的冷凝水可作为循环水补水,水耗低,因此可以解决煤气冷凝水中氨氮难处理及水平衡问题。(The invention provides a device and a method for dry type cooperative purification and indirect cooling of coal gas and oil dust of a fixed bed, belonging to the technical field of coal gas treatment. The device provided by the invention has the advantages of reasonable overall structure arrangement, good gas purification effect, energy conservation and environmental protection. Specifically, by adopting the oil dust pre-removing device 1, the dry dust collector 2 and the indirect cooler 3, dust and tar in the coal gas can be efficiently and synergistically purified and separated, and the content of impurities in the coal gas condensate is low, so that the problems of pollution and difficult treatment of waste water containing oil, phenol and dust existing in the traditional coal gasification direct cooling process can be solved; moreover, the oil dust pre-removing device 1 and the dry dust collector 2 are adopted, so that the dust and tar separation efficiency is high, and the problem of adhesion and blockage of tar contained in the coal gas to a dust removal system can be solved; by adopting the indirect cooler 3 and the stripping ammonia distillation system 4, the condensed water after ammonia nitrogen removal can be used as circulating water for water supplement, and the water consumption is low, so that the problems of difficult ammonia nitrogen treatment and water balance in the coal gas condensed water can be solved.)

1. A device for dry type cooperative purification and indirect cooling of gas, oil and dust of a fixed bed comprises

The oil dust pre-removing device (1) is provided with a raw gas inlet, a primary circulating water inlet, an oil-containing dust outlet, a primary purified gas outlet and a primary circulating water outlet;

the dry dust collector (2) is provided with a primary purified gas inlet, a scavenging gas inlet, a dust outlet and a secondary purified gas outlet, wherein the primary purified gas inlet is communicated with the primary purified gas outlet;

the indirect cooler (3) is provided with a secondary purified gas inlet, a secondary circulating water inlet, a condensate outlet, a clean gas outlet and a secondary circulating water outlet, wherein the secondary purified gas inlet is communicated with the secondary purified gas outlet;

the ammonia stripping and distilling system (4) is provided with a condensate inlet, a steam inlet, a deamination water outlet and an ammonia water outlet, wherein the condensate inlet is communicated with the condensate outlet;

and the sewage treatment system (5), the sewage treatment system (5) is provided with a deamination water inlet, a medicament inlet and a purified water outlet, wherein the deamination water inlet is communicated with the deamination water outlet, and the purified water outlet is communicated with the primary circulating water inlet and the secondary circulating water inlet.

2. The apparatus according to claim 1, characterized in that the oil dust pre-removal device (1) is a cold wall cyclone.

3. The apparatus of claim 2, wherein the cold wall cyclone is provided with a membrane wall, water jacket or coil outside the housing.

4. The device according to claim 1, wherein the dry precipitator (2) is a filter precipitator using a cloth bag as filter material.

5. The arrangement according to claim 1, characterized in that the indirect cooler (3) is a tube-in-tube heat exchanger, a plate heat exchanger or a heat pipe heat exchanger.

6. The device according to any one of claims 1 to 5, wherein the oil dust pre-removing device (1), the dry dust collector (2), the indirect cooler (3) and the stripping ammonia distillation system (4) are arranged vertically.

7. A method for carrying out dry type cooperative purification and indirect cooling on gas and oil dust of a fixed bed by adopting the device of any one of claims 1 to 6, comprising the following steps:

conveying the crude gas to an oil dust pre-removing device (1) for first purification treatment to obtain oil-containing dust and first-stage purified gas;

conveying the primary purified gas to a dry dust collector (2) for secondary purification treatment to obtain purified dust and secondary purified gas;

conveying the secondary purified gas to an indirect cooler (3) for cooling treatment to obtain condensate and clean gas;

conveying the condensate to a steam stripping ammonia distillation system (4) for ammonia distillation treatment to obtain deamination water and ammonia water;

and conveying the de-ammonia water to a sewage treatment system (5) for third purification treatment to obtain purified water, and using the purified water as circulating water for the first purification treatment and the cooling treatment.

8. The method according to claim 7, wherein the temperature of the raw gas is 180-300 ℃, and the pressure is 10-90 kPa;

the temperature of the primary purified gas is 150-220 ℃;

the dust content in the secondary purified gas is less than or equal to 10mg/Nm³The temperature of the secondary purified gas is 140-200 ℃;

the temperature of the clean coal gas is less than or equal to 40 ℃.

9. The method according to claim 7 or 8, characterized in that when the raw gas is conveyed to the oil dust pre-removing device (1), the gas velocity of a raw gas inlet is 15-25 m/s; the inner wall temperature of the oil dust pre-removing device (1) is 40-80 ℃.

10. The method according to claim 7, characterized in that the ammonia water concentration obtained by the steam stripping and ammonia distilling system (4) is 10-99.6 wt%.

Technical Field

The invention relates to the technical field of gas treatment, in particular to a device and a method for dry type cooperative purification and indirect cooling of coal gas and oil dust of a fixed bed.

Background

Currently, the coal gasification technologies that have been industrialized in China mainly include an atmospheric fixed-bed intermittent anthracite (or coke) gasification technology, an atmospheric fixed-bed anthracite (or coke) oxygen-enriched continuous gasification technology, a Lurgi (Lurgi) fixed-bed coal pressure gasification technology, an ash agglomeration fluidized bed pulverized coal gasification technology, an ender boiling bed (winkler) pulverized coal gasification technology, a GE Texaco (Texaco) coal water slurry pressure gasification technology, a Shell (Shell) dry coal powder pressure gasification technology, a GSP dry coal powder pressure gasification technology, a pure oxygen continuous gasification technology, and the like. The coal gasification technologies are all fixed bed coal gasification technologies, and include an atmospheric fixed bed coal gasification technology and a pressurized fixed bed coal gasification technology, which are classified by pressing force.

The atmospheric fixed bed coal gasification technology is a process of converting coal into coal gas under atmospheric pressure by using air, steam and oxygen as gasification agents. The technology is mature and reliable, simple to operate, low in investment and short in construction period, and is widely used for preparing fuel gas in the industries of metallurgy, building materials, machinery and the like in China; the method is used for preparing synthesis gas in small and medium-sized ammonia synthesis plants and methanol plants; for preparing CO and H in small-sized chemical equipment with less gas consumption₂. The coal gasification technology has the defects that direct water washing is adopted for cooling and dedusting, cooling water is evaporated through an evaporation tower, pollutants such as tar, phenol, ammonia, VOCs and the like are discharged inorganically to the environment, and the coal gasification technology has great potential environmental protection hazards.

The lurgi fixed bed coal pressure gasification technology is representative of the pressure fixed bed coal gasification technology, and has been industrialized in the 30 s of the 20 th century, but the process generates a large amount of condensed sewage to be treated. And because of adopting the direct cooling (water washing) process, the produced sewage also contains a large amount of tar, phenol, ammonia and other substances, a tar recovery device needs to be built, and the phenol and ammonia recovery and biochemical treatment device increases the investment and the raw material consumption.

The problems of large dust carrying-out amount, incomplete dust removal and the need of water direct cooling for dust removal and cooling exist in the early or current fixed bed coal gasification technology, so that not only is a large amount of grey water circulated, but also in the traditional direct cooling, cooling water is directly contacted with coal gas for heat and mass transfer, and the coal gas is cooled to normal temperature. Although the method has simple process and good cooling effect, the direct cooling dust removal effect is general, and dust in the gas is discharged into cooling water and cannot be completely removed even if a water treatment settling facility is additionally arranged for treatment, so that the investment of fine dust removal and water treatment facilities is large, the efficiency is low, the operation management is difficult, and the method becomes a fort which restricts the survival and development of coal gasification enterprises. Therefore, the development of the coal gas treatment process with good purification effect, energy conservation and environmental protection has important environmental protection, economic and social significance.

Disclosure of Invention

The invention aims to provide a device and a method for dry type cooperative purification and indirect cooling of coal gas and oil dust of a fixed bed.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a device for dry type cooperative purification and indirect cooling of coal gas and oil dust of a fixed bed, which comprises

The device comprises an oil dust pre-removing device 1, wherein the oil dust pre-removing device 1 is provided with a raw gas inlet, a primary circulating water inlet, an oil-containing dust outlet, a primary purified gas outlet and a primary circulating water outlet;

the dry dust collector 2 is provided with a primary purified gas inlet, a scavenging gas inlet, a dust outlet and a secondary purified gas outlet, wherein the primary purified gas inlet is communicated with the primary purified gas outlet;

the indirect cooler 3 is provided with a secondary purified gas inlet, a secondary circulating water inlet, a condensate outlet, a clean gas outlet and a secondary circulating water outlet, wherein the secondary purified gas inlet is communicated with the secondary purified gas outlet;

the ammonia stripping and distilling system 4 is provided with a condensate inlet, a steam inlet, a deamination water outlet and an ammonia water outlet, wherein the condensate inlet is communicated with the condensate outlet;

and the sewage treatment system 5, the sewage treatment system 5 is provided with a deamination water inlet, a medicament inlet and a purified water outlet, wherein the deamination water inlet is communicated with the deamination water outlet, and the purified water outlet is communicated with the primary circulating water inlet and the secondary circulating water inlet.

Preferably, the oil dust pre-removing device 1 is a cold wall type cyclone separator.

Preferably, the shell of the cold wall cyclone is externally provided with a membrane wall, a water jacket or a coil.

Preferably, the dry dust collector 2 is a filter type dust collector, and the filter material used by the filter type dust collector is a cloth bag.

Preferably, the indirect cooler 3 is a tube type heat exchanger, a plate type heat exchanger or a heat pipe heat exchanger.

Preferably, the oil dust pre-removing device 1, the dry dust collector 2, the indirect cooler 3 and the stripping ammonia distillation system 4 are arranged vertically.

The invention provides a method for performing fixed bed gas oil dust dry type cooperative purification and indirect cooling by adopting the device in the technical scheme, which comprises the following steps:

conveying the crude gas to an oil dust pre-removing device 1 for first purification treatment to obtain oil-containing dust and first-stage purified gas;

conveying the primary purified gas to a dry dust collector 2 for secondary purification treatment to obtain purified dust and secondary purified gas;

conveying the secondary purified gas to an indirect cooler 3 for cooling treatment to obtain condensate and clean gas;

conveying the condensate to a steam stripping ammonia distillation system 4 for ammonia distillation treatment to obtain deamination water and ammonia water;

and conveying the de-ammonia water to a sewage treatment system 5 for third purification treatment to obtain purified water, and using the purified water as circulating water for the first purification treatment and cooling treatment.

Preferably, the temperature of the raw gas is 180-300 ℃, and the pressure is 10-90 kPa;

the temperature of the primary purified gas is 150-220 ℃;

the dust content in the secondary purified gas is less than or equal to 10mg/Nm³The temperature of the secondary purified gas is 140-200 ℃;

the temperature of the clean coal gas is less than or equal to 40 ℃.

Preferably, when the raw gas is conveyed into the oil dust pre-removing device 1, the gas velocity at the inlet of the raw gas is 15-25 m/s; the temperature of the inner wall of the oil dust pre-removing device 1 is 40-80 ℃.

Preferably, the concentration of the ammonia water obtained by the stripping ammonia distillation system 4 is 10-99.6 wt%.

The invention provides a device for dry type collaborative purification and indirect cooling of coal gas and oil dust of a fixed bed, which comprises an oil dust pre-removing device 1, a dry type dust remover 2, an indirect cooler 3, a steam stripping ammonia distillation system 4 and a sewage treatment system 5. Specifically, by adopting the oil dust pre-removing device 1, the dry dust collector 2 and the indirect cooler 3, dust and tar in the coal gas can be efficiently and synergistically purified and separated, and the content of impurities in the coal gas condensate is low, so that the problems of pollution and difficult treatment of waste water containing oil, phenol and dust existing in the traditional coal gasification direct cooling process can be solved; moreover, the oil dust pre-removing device 1 and the dry dust collector 2 are adopted, so that the dust and tar separation efficiency is high, and the problem of adhesion and blockage of tar contained in the coal gas to a dust removal system can be solved; by adopting the indirect cooler 3 and the stripping ammonia distillation system 4, the condensed water after ammonia nitrogen removal can be used as circulating water for water supplement, and the water consumption is low, so that the problems of difficult ammonia nitrogen treatment and water balance in the coal gas condensed water can be solved.

Furthermore, the dry type dust collector 2 in the device provided by the invention is made of cloth bags, so that the service life is long, no complex process equipment is needed, the investment and operation cost are low, and the device is suitable for industrial application.

In addition, the dry dust collector 2 of the invention can solve the problems of huge equipment, large floor area, higher investment, large water consumption, high operation cost and the like of the existing wet dust collection process, and the problems of high manufacturing cost, high requirements on gas components and pressure and the like of the existing dry film dust collection technology.

Furthermore, the oil dust pre-removing device 1, the dry dust collector 2, the indirect cooler 3 and the steam stripping ammonia distilling system 4 in the device provided by the invention are vertically arranged, so that the device has small volume and small occupied area.

The invention provides a method for performing fixed bed gas oil dust dry type cooperative purification and indirect cooling by adopting the device in the technical scheme, and the method provided by the invention has the advantages of high dust and tar separation efficiency, small waste water generation amount, greatly reduced waste water treatment cost and difficulty, good economic benefit, outstanding environmental protection benefit, and easy upgrading and reconstruction, industrial popularization and application of the traditional gas cooling and purifying system.

Drawings

FIG. 1 is a schematic structural diagram of a fixed bed gas oil dust dry type cooperative purification and indirect cooling device in the invention, wherein, 1-oil dust pre-removing device, 2-dry dust remover, 3-indirect cooler, 4-stripping ammonia distillation system, 5-sewage treatment system;

FIG. 2 is a flow chart of the present invention for treating coal gas by using a fixed bed coal gas oil dust dry type cooperative purification and indirect cooling device.

Detailed Description

The invention provides a device for dry type collaborative purification and indirect cooling of oil dust in fixed bed gas, which comprises an oil dust pre-removing device 1, a dry type dust remover 2, an indirect cooler 3, a stripping ammonia distillation system 4 and a sewage treatment system 5, wherein the structural schematic diagram is shown in figure 1, and the following detailed description is provided by combining figure 1.

The device provided by the invention comprises an oil dust pre-removing device 1, wherein the oil dust pre-removing device 1 is provided with a crude gas inlet, a primary circulating water inlet, an oil-containing dust outlet, a primary purified gas outlet and a primary circulating water outlet. The installation position of each inlet and outlet of the oil dust pre-removing device 1 is not particularly limited in the present invention, and the installation position known to those skilled in the art can be adopted. In the invention, the crude gas is subjected to primary purification treatment (namely, first purification treatment) in an oil dust pre-removing device 1.

As an embodiment of the present invention, the oil-dust pre-removing device 1 is a cold-wall cyclone separator, specifically, the raw gas enters the oil-dust pre-removing device 1 tangentially, tar in the raw gas directly condenses after contacting the cold wall and forms an adhesion effect with dust, which is beneficial for the tar and dust to separate from the raw gas under the action of centrifugal force, inertia and gravity, so as to remove most of the dust and tar in the raw gas, obtain oil-containing dust and primary purified gas, thereby meeting the requirement of the rear-end dry dust collector 2 on the gas index, and reducing the influence of the dust and tar on corrosion, blockage and the like of system pipelines and equipment. As an embodiment of the invention, the shell of the cold wall cyclone separator is externally provided with a membrane wall, a water jacket or a coil.

The device provided by the invention comprises a dry dust collector 2, wherein the dry dust collector 2 is provided with a primary purified gas inlet, a scavenging gas inlet, a dust outlet and a secondary purified gas outlet, and the primary purified gas inlet is communicated with the primary purified gas outlet. In the invention, the purge gas can be periodically conveyed into the dry dust remover 2 through the purge gas inlet so as to realize the periodic cleaning of the dry dust remover 2; the purge gas may be an inert gas such as nitrogen or carbon dioxide. The installation position of each inlet and outlet of the dry dust collector 2 is not particularly limited in the present invention, and may be any installation position known to those skilled in the art. The invention carries out deep purification treatment (namely, second purification treatment) on the primary purified gas in the dry dust collector 2 so as to remove residual tar in the gas and reduce the dust content in the gas to 10mg/Nm³Then, the dust and the second-stage purified gas are obtained.

As an embodiment of the present invention, the dry dust collector 2 is a filter type dust collector, and the filter material used in the filter type dust collector is a cloth bag. As an embodiment of the present invention, the cloth bag is coated with Polytetrafluoroethylene (PTFE), and specifically, the dry type dust collector 2 is a PTFE + PTFE coated cloth bag.

The device provided by the invention comprises an indirect cooler 3, wherein the indirect cooler 3 is provided with a secondary purified gas inlet, a secondary circulating water inlet, a condensate outlet, a clean gas outlet and a secondary circulating water outlet, and the secondary purified gas inlet is communicated with the secondary purified gas outlet. The position of each inlet/outlet of the indirect cooler 3 is not particularly limited in the present invention, and any position known to those skilled in the art may be used. The invention indirectly cools the secondary purified gas in an indirect cooler 3 so as to cool the gas to below 40 ℃ and obtain condensate and clean gas.

As an embodiment of the present invention, the indirect cooler 3 is a tube type heat exchanger, a plate type heat exchanger, or a heat pipe type heat exchanger. As an embodiment of the invention, during the actual operation of the cooling treatment, the secondary purified gas flows away from the pipe path to prevent blockage and facilitate cleaning.

The device provided by the invention comprises a steam stripping ammonia distillation system 4, wherein the steam stripping ammonia distillation system 4 is provided with a condensate inlet, a steam inlet, a deamination water outlet and an ammonia water outlet, and the condensate inlet is communicated with the condensate outlet. The present invention is not particularly limited to the positions of the inlets and outlets of the ammonia stripping and distilling system 4, and the positions may be those known to those skilled in the art. According to the invention, the condensate is subjected to ammonia distillation treatment in the steam stripping ammonia distillation system 4 so as to reduce the content of ammonia nitrogen in the condensate and obtain the ammonia-removed water and ammonia water.

As an embodiment of the invention, the oil dust pre-removing device 1, the dry dust collector 2, the indirect cooler 3 and the stripping ammonia distillation system 4 are vertically arranged, so that the equipment volume is small and the occupied area is small.

The device provided by the invention comprises a sewage treatment system 5, wherein the sewage treatment system 5 is provided with a deamination water inlet, a medicament inlet and a purified water outlet, wherein the deamination water inlet is communicated with the deamination water outlet, and the purified water outlet is communicated with the primary circulating water inlet and the secondary circulating water inlet. In the invention, a proper medicament can be added into the sewage treatment system 5 through the medicament inlet so as to ensure the purification effect. The present invention is not particularly limited to the installation position of each inlet/outlet of the sewage treatment system 5, and the installation position known to those skilled in the art may be adopted. The invention performs purification treatment (i.e. third purification treatment) on the deamination water in the sewage treatment system 5 so as to obtain purified water, and the purified water is used as circulating water, thereby reducing the water consumption of the system.

The invention provides a method for performing fixed bed gas oil dust dry type cooperative purification and indirect cooling by adopting the device in the technical scheme, which comprises the following steps:

conveying the crude gas to an oil dust pre-removing device 1 for first purification treatment to obtain oil-containing dust and first-stage purified gas;

conveying the primary purified gas to a dry dust collector 2 for secondary purification treatment to obtain purified dust and secondary purified gas;

conveying the secondary purified gas to an indirect cooler 3 for cooling treatment to obtain condensate and clean gas;

conveying the condensate to a steam stripping ammonia distillation system 4 for ammonia distillation treatment to obtain deamination water and ammonia water;

and conveying the de-ammonia water to a sewage treatment system 5 for third purification treatment to obtain purified water, and using the purified water as circulating water for the first purification treatment and cooling treatment.

FIG. 2 is a flow chart of the gas treatment by the device for the dry type cooperative purification and indirect cooling of oil dust in the fixed bed gas in the present invention, and the gas treatment flow is described below with reference to FIG. 2.

According to the invention, the crude gas is conveyed to an oil dust pre-removing device 1 for first purification treatment, so that oil-containing dust and first-stage purified gas are obtained. The source of the raw gas is not particularly limited, and the raw gas from which the raw gas is well known to those skilled in the art can be used, and the raw gas is preferably treated by aiming at the raw gas of the batch type fixed bed gasification furnace; in the practice of the inventionIn the example, the raw gas generated by the intermittent fixed bed gasification furnace firstly passes through the original cyclone separator and the waste heat boiler and then is sent into the fixed bed gas and oil dust dry type cooperative purification and indirect cooling device for treatment; wherein, the temperature of the raw gas (namely the raw gas to be treated) entering the device is preferably 180-300 ℃, and can be 180 ℃, 220 ℃ or 300 ℃; the pressure is preferably 10-90 kPa, and specifically 10kPa, 50kPa or 90 kPa; the water content is preferably less than or equal to 35 wt%, and more preferably 15-30 wt%; the dust content is preferably less than or equal to 40g/Nm³More preferably 20 to 30g/Nm³(ii) a The tar content is preferably less than or equal to 30mg/Nm³More preferably 10 to 20g/Nm³。

In the invention, when the raw gas is conveyed to the oil dust pre-removing device 1, the gas velocity at the raw gas inlet is preferably 15-25 m/s, and specifically can be 15m/s, 20m/s or 25 m/s; the inner wall temperature of the oil dust pre-removing device 1 is preferably 40-80 ℃, and specifically can be 40 ℃, 60 ℃ or 80 ℃. The present invention is not particularly limited to specific operating conditions for the first purification treatment, and operating conditions known to those skilled in the art may be used.

In the invention, oil-containing dust and primary purified gas are obtained after the first purification treatment, and the oil-containing dust can be sent to a boiler in a factory for incineration and utilization; and conveying the primary purified gas to a dry dust collector 2 for secondary purification treatment to obtain purified dust and secondary purified gas. In the invention, the temperature of the primary purified gas is preferably 150-220 ℃, and specifically can be 150 ℃, 180 ℃ or 220 ℃; the present invention is not particularly limited to specific operating conditions for the second purification treatment, and may employ operating conditions known to those skilled in the art.

In the invention, purified dust and secondary purified coal gas are obtained after the second purification treatment, and the purified dust can be sent to a boiler in a factory for incineration and utilization; and conveying the secondary purified gas to an indirect cooler 3 for cooling treatment to obtain condensate and clean gas. In the invention, the temperature of the secondary purified gas is preferably 140-200 ℃, and specifically can be 140 ℃, 160 ℃ or 200 ℃; the content of dust is preferably less than or equal to10mg/Nm³. The specific operating conditions of the cooling treatment are not particularly limited in the present invention, and the required cooling effect can be ensured by using the operating conditions known to those skilled in the art.

In the invention, after cooling treatment, condensate and clean coal gas are obtained, the temperature of the clean coal gas is preferably less than or equal to 40 ℃, more preferably 30-35 ℃, and the clean coal gas can be used as synthesis gas, fuel gas and the like according to the requirements of users; and the condensate is conveyed to a steam stripping ammonia distillation system 4 for ammonia distillation treatment to obtain deamination water and ammonia water. In the invention, the concentration of the ammonia water is preferably 10-99.6 wt%. The invention has no special limitation on the specific operating conditions of the ammonia distillation treatment, and determines the proper conditions according to the actual requirements, so that the ammonia nitrogen content in the condensate is reduced, and the ammonia water with proper concentration is obtained.

In the invention, ammonia distillation treatment is carried out to obtain deamination water and ammonia water; wherein, the ammonia water can be sold as a product and can also be used as a gas desulfurizer for a flue gas desulfurization process of boilers in a factory; and (3) conveying the ammonia-removed water to a sewage treatment system 5 for third purification treatment to obtain purified water, and using the purified water as circulating water for the first purification treatment and the cooling treatment. In the present invention, the type and amount of the chemical used in the third purification process may be selected according to the nature of the deamination water, and the present invention is not particularly limited thereto.

The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.