JP2001179047A - Wastewater treatment facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wastewater treatment facility capable of effectively treating exhaust gas, wastewater or the like at a low cost. SOLUTION: A wastewater treatment facility is equipped with a wastewater cleaning system 21 and a gypsum formation system 22. Hazardous components contained in the exhaust gas generated from a boiler 20 are treated by the wastewater cleaning system 21, and gypsum is generated from lime water casted when the exhaust gas is treated, by the gypsum generation system 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production and production of power and products in various energy generation and product production departments.
The present invention relates to a wastewater treatment apparatus for effectively treating exhaust gas, wastewater, and the like that are simultaneously discharged during a manufacturing process.

[0002]

2. Description of the Related Art For example, in plants such as power plants and refuse incineration plants, specific substances such as heavy metals, fluorine,
Contain boron, ammonia, etc., and consider that specific substances are harmful to the human body and the natural environment. To protect the human body and the natural environment, measures are taken to treat harmful substances in order to comply with the regulations.

For example, means for treating exhaust gas or exhaust gas discharged from a power plant includes, for example, JP-A-11-1
As seen in JP 04450, an evaporative concentration means is used.

[0004] As shown in FIG.
It comprises a storage tank 1, an evaporator 2, a heater 3, a sedimentation tank 4, a kneader 5, etc., supplies exhaust gas to the storage tank 1, makes it soluble with the help of an absorbent, and supplies the aqueous solution to the evaporator 2. Here, while being evaporated by the heating source from the heater 3, the gypsum contained in the vapor is precipitated and separated in the precipitation tank 4,
The separated gypsum is supplied as seed crystals to the evaporator 2, while the concentrated water after separation is supplied to the kneader 5 via the storage tank 6, and further, the solidification aid supplied to the kneader 5 from the premixer 7. Then, the concentrated water is solidified.

On the other hand, in a refuse incineration plant, during the incineration of refuse, dioxin is contained in exhaust gas generated at a high temperature, for example, 800 ° C. to 900 ° C., so that the exhaust gas is sprayed with water and rapidly cooled to 300 ° C. to 400 ° C. To keep the dioxin concentration low.

[0006] The quenching device used at that time is, for example, disclosed in Japanese Utility Model Publication No. 6-41604, which is a spray dryer of a rotary atomizer disk type with an inclined upper plate, and disclosed in Japanese Utility Model Application Laid-Open No. 7-37301. There is a universal pressure nozzle holder type spray dryer that has been used.

In the former, for example, as shown in FIG. 6, an upper plate inclined type atomizer disk 10 which is driven to rotate by a motor 9 is accommodated in a container 8 and a drain pipe 11 is attached to the rotating upper plate inclined type atomizer disk 10. Drainage and hot air tube 1
The hot air from 2 is blown out to efficiently dry the wastewater.

In the latter, for example, as shown in FIG. 7, the heating gas G is supplied from the head side of the container 13 and the waste water M from the nozzle 14 provided on the bottom side of the container 13 is supplied.
Is sprayed, and the wastewater M is brought into direct contact with the heating gas G to dry the wastewater M, thereby generating a particulate product S.

Further, a denitration apparatus for treating sulfur contained in exhaust gas using one of the above-described inclined inclined rotary atomizer disk system and universal pressure nozzle holder system includes a spray dryer, for example. As shown in FIG. 8, when the exhaust gas from the boiler 15 is treated by the spray dryer 16, the sulfur content is reacted and removed with the supplied alkaline aqueous solution, and then the ash and salts are removed by the dust collector 17, and then the exhaust gas is collected into a chimney. Release to the atmosphere via 18 has been implemented.

As described above, in a conventional power generation plant or a waste incineration plant, harmful components contained in the exhaust gas and adversely affecting the human body and the like are separated and treated by a combination of mechanical means and chemical means to protect the environment. Had to deal with it.

[0011]

In the conventional evaporative concentration means shown in FIG. 5, a heating source from a heater 3 is supplied to an evaporator 2 and contains scale components such as gypsum, silica, and insoluble suspended substances. It employs a so-called heat transfer method that evaporates the aqueous solution.
There is naturally a limit in concentrating the aqueous solution so as not to deposit, and it has become insufficient to deposit more plaster as a seed crystal, resulting in inefficient energy consumption.

In addition, in the conventional evaporation and concentration means, when gypsum as a seed crystal is precipitated from an aqueous solution, silica and other insoluble suspended substances as other scale components are also precipitated at the same time. There were inconveniences and defects such as labor and cost.

[0013] Further, in the refuse incineration plant, there is no means to suppress the dioxin concentration by adding water to the exhaust gas generated during incineration and to remove harmful components contained in the various kinds of wastewater. By incorporating the spray dryer shown in FIG. 6 or the spray dryer shown in FIG. 7, effective treatment of exhaust gas and wastewater has been desired.

In consideration of the difficulty in securing land, a waste incineration plant installed in an urban area has been required to be compact and have a high processing capacity.

The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a wastewater treatment apparatus that can effectively treat exhaust gas, wastewater, and the like discharged from an energy generation department or the like at a relatively low cost. With the goal.

[0016]

According to a first aspect of the present invention, there is provided a wastewater treatment apparatus for controlling the concentration of NOx in exhaust gas generated from a boiler, and the exhaust gas. A effluent purification system to dry harmful components contained in various effluents into powdery solids while pouring lime water into sulfur to remove sulfur, and produced when pouring the lime water into the exhaust gas A gypsum producing system that produces gypsum by drying gypsum water.

According to a second aspect of the present invention, there is provided a wastewater treatment apparatus comprising a denitration apparatus for reducing a NOx concentration of exhaust gas generated from a boiler to a low level. , A dust collector that captures the ash contained in the exhaust gas that has passed through the air preheater, a desulfurization device that adds lime water to the exhaust gas to generate sulfur compounds, and filters the wastewater from the desulfurization device with filtered water, desulfurized wastewater, and gypsum water. And a gypsum separator, which is provided in a bypass circuit that connects the inlet side and the outlet side of the air preheater to each other, and removes harmful components contained in desulfurization wastewater and various kinds of wastewater supplied from the gypsum separator. It is provided with a spray drier which produces a powdery solid by drying and supplies it to the dust collector.

In order to achieve the above object, in the wastewater treatment apparatus according to the present invention, the spray dryer is provided with another dust collector at the outlet side and at the inlet side of the dust collector. It is provided.

In order to achieve the above object, in the wastewater treatment apparatus according to the present invention, the bypass circuit has a blower on the inlet side of the spray dryer.

According to a fifth aspect of the present invention, there is provided a wastewater treatment apparatus according to the present invention, wherein the gypsum generation system is configured to dry gypsum water from a gypsum separator of a wastewater purification system. And a heat exchanger that supplies a heating medium to the spray dryer and heats the heating medium with steam from a boiler.

Further, in order to achieve the above object, the wastewater treatment apparatus according to the present invention suppresses the NOx concentration of the exhaust gas generated from a boiler into which liquefied natural gas is injected as fuel. A denitration device, a heat exchanger that heats air from the atmosphere using steam from the boiler as a heating source, and a dust collector that dries harmful components contained in various wastewaters with high-temperature air to produce powdery solids And an ammonia treatment unit that captures ash from the exhaust gas containing powdered solids from the spray dryer with the dust collector and removes ammonia contained in the exhaust gas.

Further, in order to achieve the above object, the wastewater treatment apparatus according to the present invention suppresses the dioxin concentration of the exhaust gas generated from the refuse incinerator and reduces the concentration of dioxin supplied from the waste incinerator. A spray dryer that dries harmful components contained in various kinds of wastewater to produce a powder solid and supplies it to a dust collector, and traps ash in the exhaust gas containing the powder solid from the spray dryer with the dust collector. And an exhaust gas treatment device for introducing slaked lime water into chlorine contained in exhaust gas to remove and react the same.

In order to achieve the above object, the wastewater treatment apparatus according to the present invention, as set forth in claim 8, wherein the wastewater treatment apparatus removes the generated wastewater when slaked lime water is supplied to the exhaust gas. It has a drainage circulation system for supplying to the spray dryer.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a waste water treatment apparatus according to the present invention will be described below with reference to the drawings and reference numerals attached to the drawings.

FIG. 1 is a schematic system diagram showing a first embodiment in which a wastewater treatment apparatus according to the present invention is applied to a power plant using, for example, coal or heavy oil as fuel.

The wastewater treatment apparatus according to the present embodiment regenerates a wastewater purification system 21 for purifying exhaust gas generated from a boiler 20 and wastewater discharged from other equipment of a power plant and lime water supplied to the wastewater purification system 21. And a gypsum generation system 22 that generates and collects gypsum as a product.

The waste water purification system 21 includes a denitration device 23, an air preheater 24, a dust collector 25, and a denitration device 26 in order along the flow of the exhaust gas discharged from the boiler 20, and from the inlet side of the air preheater 24. Branch and air preheater 2
The blower 28 and the first spray dryer 29 are sequentially arranged along the flow of the exhaust gas in the bypass circuit 27 connected to the outlet side of
While the gypsum separator 30 is attached to the denitration device 26.
It has.

The gypsum generating system 22 generates gypsum by using the heat exchanger 31 using steam generated from the boiler 20 as a heating source and the gypsum water supplied from the gypsum separator 30 of the waste water purification system 21 as a product. -A second spray dryer 32 for collecting is provided.

The first spray drier 29 and the second spray drier 32 are either an upper plate inclined type atomizer disk type shown in FIG. 6 or a universal pressure nozzle holder type shown in FIG. Either one may be applied.

In the waste water purification system 21 having such a configuration, the exhaust gas generated from the boiler 20 and having a temperature of about 350 ° C. or higher is subjected to a catalytic action in a denitration device 23 to remove nitrogen oxides NOx, and then to preheat air. In the chamber 24, the temperature is increased to, for example, about 150 ° C. or more, and supplied to the dust collector 25. The reason why the exhaust gas is heated to a temperature of about 150 ° C. or higher by the air preheater 24 is to take account of the acid dew point for preventing corrosion of the dust collector 25.

The exhaust gas supplied to the dust collector 25 is supplied to a desulfurization device 26 after separating ash and reacts with the lime water supplied there to remove sulfur, and then discharged to the atmosphere from a chimney 33. Is done. Note that the dust collector 25 may supply ammonia to the upstream side in order to prevent the generation of acid ash.

An aqueous solution containing calcium sulfate and the like generated by the reaction between the sulfur content of the exhaust gas and the lime water in the denitration device 26 is supplied to the gypsum separator 30, and the filtered water purified therefrom, It is separated into gypsum water and filtered water (desulfurization effluent) containing harmful components such as boron, fluorine, heavy metals, and ammonia and scale components such as gypsum and silica.

The purified filtered water separated from the aqueous solution containing calcium sulfate and the like is returned to the desulfurizer 26 and reused.

The filtered water (denitrification wastewater) containing harmful components such as boron and scale components such as gypsum is supplied to the first spray dryer 29. The chlorine separated by the gypsum separator 30 is blown out of the system because it causes corrosion.

On the other hand, a part of the exhaust gas that has exited from the denitration device 23 is supplied to a first spray dryer 29 through a blower 28 of a bypass circuit 27, where the filtered water containing harmful components such as boron described above is filtered. (Denitrification wastewater), and various wastewater such as wastewater from condensate and desalination equipment of power plants, sludge water from the makeup water system, domestic water, etc., and the temperature of boron compounds, fluorine compound heavy metals, gypsum, silica, etc. 350
A component which does not evaporate below ℃ is supplied to the dust collector 25 as a powdery solid, and is captured together with the above-mentioned ash.

On the other hand, in the gypsum producing system 22, high-temperature air from the atmosphere using steam supplied from the boiler 15 to the heat exchanger 31 as a heating source is supplied to the second spray dryer 32, and the above-mentioned waste water purifying system 21 is provided. The gypsum water from the gypsum separator 30 is dried, the steam generated at that time is supplied to other devices, and the dried gypsum is generated as a product.

As described above, according to the present embodiment, the N
A wastewater purification system 21 that removes Ox with a denitration device 23 and turns harmful components and scale components contained in the wastewater into powdery solids with a first spray dryer 29, and a second sprayer with lime water to be supplied during flue gas desulfurization. The gypsum generation system 22 that generates and collects gypsum as a product in the dryer 32 has been combined for multipurpose use, so that wastewater can be treated at a relatively low cost while reusing resources, and is included in the wastewater. Harmful components and the like can be reliably removed to sufficiently address environmental conservation.

FIG. 2 is a schematic system diagram showing a second embodiment in which the wastewater treatment apparatus according to the present invention is applied to, for example, a power plant using LNG (liquefied natural gas) as fuel.
The same parts as those in the first embodiment are denoted by the same reference numerals.

In this embodiment, since LNG, which is clean energy, is used as fuel to be supplied to the boiler 20, NOx of exhaust gas generated from the boiler 20 is processed by the denitration device 23 and the air preheater 24 and the chimney 33 From the condensate and desalination equipment of the power plant, sludge water, domestic wastewater, and other various wastewater that are supplied to the spray dryer 34 while being discharged to the spray dryer 34. In consideration of the above, the dust collector 25 and the ammonia processing unit 35 are provided on the outlet side of the spray dryer 34.

The spray dryer 34 employs one of an upper plate inclined type atomizer disk type shown in FIG. 6 and a universal pressure nozzle holder type shown in FIG. 7, for example. As in the first embodiment, the boiler 2 is used as a heating source for drying harmful components and scale components contained in the wastewater of the boiler.
From 0, high-temperature air after heat exchange between steam and air supplied to the heat exchanger 31 is used.

Further, the spray dryer 34 dries harmful components and scale components contained in various kinds of waste water into powdery solids, captures ash from the powdery solids with the dust collector 25, and converts ammonia into ammonia. After being processed in the processing section, the residue is discharged outside the vessel.

As described above, in the present embodiment, the boiler 20
Of the exhaust gas generated from the waste gas, NOx is processed by the desulfurization unit 23, and harmful components and scale components contained in various wastewaters are dried by the spray dryer 34 into powdery solids, which are further contained in various wastewaters. Since ammonia is treated in the ammonia treatment section 35, harmful components and the like can be reliably removed, and sufficient measures can be taken for environmental conservation.

FIG. 3 is a schematic system diagram showing a third embodiment in which the wastewater treatment apparatus according to the present invention is applied to a power plant using, for example, coal or heavy oil as fuel. The same parts as those in the first embodiment are denoted by the same reference numerals.

In this embodiment, the harmful components and scale components contained in the various wastewaters are dried by the spray dryer 36 into powdery solids. Another dust collector 37 is provided on the side, and is separately provided from the dust collector 25 provided on the outlet side of the air preheater 24. In addition, other configurations are
Since it is the same as the first embodiment, the description is omitted.

As described above, in this embodiment, another dust collector 37 is provided at the outlet side of the spray dryer 36, and excess ash generated from the spray dryer 36 is collected by the dust collector 37.
Therefore, the drainage purification system 21 such as the spray dryer 36, the desulfurization device 26, and the gypsum separator 30 can be stably operated.

FIG. 4 is a schematic system diagram showing a fourth embodiment in which the wastewater treatment apparatus according to the present invention is applied to, for example, a waste incineration plant. The same parts as those in the first embodiment are denoted by the same reference numerals.

In the present embodiment, the spray dryer 3 is sequentially arranged along the flow of the exhaust gas generated from the refuse incinerator 38.
9. A dust collector 25, an exhaust gas treatment device 40, a drainage circulation system 41 for supplying waste water from the exhaust gas treatment device 40 to the spray dryer 39, and a chimney 33 are provided. Various drainage such as drainage and miscellaneous drainage in plant and drainage circulation system 4
The wastewater supplied from 1 is added to cool the exhaust gas to keep the dioxin concentration low, and the harmful components and scale components contained in the various wastewater are dried to a powdery solid, which is contained in the solid. The ash is captured by the dust collector 25, and slaked lime water is further added to the flue gas treatment device 40 to remove chlorine and the like contained in the flue gas and the flue gas is released from the chimney 33 to the atmosphere. Spray dryer 3 through drainage circulation system 41
9, and reused for lowering the concentration of dioxin and for solidifying powdery solids such as harmful components.

As described above, the present embodiment includes the spray dryer 39, the dust collector 25, and the exhaust gas treatment device 40,
Dioxin concentration generated from exhaust gas is kept low, harmful components and scale components contained in various kinds of supplied wastewater are converted into powdery solids to make them harmless, and the plant is simplified, so sufficient for environmental conservation. It is possible to install a waste incineration plant even in an urban area where it is difficult to secure large land.

[0049]

As described above, the wastewater treatment apparatus according to the present invention lowers the concentration of NOx generated from exhaust gas, reacts and removes sulfur, and also removes harmful components contained in various supplied wastewater. Since a means for converting the scale component into a powdery solid is provided, it is possible to sufficiently cope with environmental conservation.

[Brief description of the drawings]

FIG. 1 is a schematic system diagram showing a first embodiment of a wastewater treatment device according to the present invention.

FIG. 2 is a schematic system diagram showing a second embodiment of the wastewater treatment device according to the present invention.

FIG. 3 is a schematic system diagram showing a third embodiment of the wastewater treatment apparatus according to the present invention.

FIG. 4 is a schematic system diagram showing a fourth embodiment of the wastewater treatment device according to the present invention.

FIG. 5 is a schematic system diagram showing a conventional desulfurization wastewater treatment device.

FIG. 6 is a conceptual diagram showing a conventional spray dryer.

FIG. 7 is a conceptual diagram showing another conventional spray dryer.

FIG. 8 is a schematic system diagram showing a conventional refuse incineration plant.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 storage tank 2 evaporator 3 heater 4 sedimentation tank 5 kneader 6 storage tank 7 premixer 8 container 9 motor 10 upper plate inclined atomizer disk 11 drainage pipe 12 hot air pipe 13 container 14 nozzle 15 boiler 16 spray dryer 17 dust collector 18 chimney Reference Signs List 20 boiler 21 wastewater purification system 22 gypsum generation system 23 denitration device 24 air preheater 25 dust collector 26 denitration device 27 bypass circuit 28 blower 29 first spray dryer 30 gypsum separator 31 heat exchanger 32 second spray dryer 33 chimney 34 spray dryer 35 Ammonia treatment unit 36 Spray dryer 37 Dust collector 38 Waste incinerator 39 Spray dryer 40 Exhaust gas treatment device 41 Drainage circulation system

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[Procedure amendment]

[Submission date] January 22, 2001 (2001.1.2)
2)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Wastewater treatment equipment

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production and production of power and products in various energy generation and product production departments.
The present invention relates to a wastewater treatment device for effectively treating wastewater discharged during a manufacturing process.

[0002]

2. Description of the Related Art For example, in plants such as power plants and refuse incineration plants, specific substances such as heavy metals, fluorine,
Contain boron, ammonia, etc., and consider that specific substances are harmful to the human body and the natural environment. To protect the human body and the natural environment, measures are taken to treat harmful substances in order to comply with the regulations.

For example, as a means for treating exhaust gas discharged from a power plant or an exhaust gas discharged from a chemical plant, evaporating and concentrating means is used, for example, as disclosed in JP-A-11-104450. .

[0004] As shown in FIG.
It comprises a storage tank 1, an evaporator 2, a heater 3, a sedimentation tank 4, a kneader 5, etc., supplies exhaust gas to the storage tank 1, makes it soluble with the help of an absorbent, and supplies the aqueous solution to the evaporator 2. Here, while being evaporated by the heating source from the heater 3, the gypsum contained in the vapor is precipitated and separated in the precipitation tank 4,
The separated gypsum is supplied as seed crystals to the evaporator 2, while the concentrated water after separation is supplied to the kneader 5 via the storage tank 6, and further, the solidification aid supplied to the kneader 5 from the premixer 7. Then, the concentrated water is solidified.

On the other hand, in a refuse incineration plant, during the incineration of refuse, dioxin is contained in exhaust gas generated at a high temperature, for example, 800 ° C. to 900 ° C., so that the exhaust gas is sprayed with water and rapidly cooled to 300 ° C. to 400 ° C. To keep the dioxin concentration low.

[0006] In the spraying device used at that time, a nozzle is used because it does not block for spraying clean water.
On the other hand, in order to turn high-concentration solids into powder, for example, a spray dryer of an upper plate inclined type atomizer disk system disclosed in Japanese Utility Model Publication No. 6-41604 or Japanese Utility Model Publication No. 7-37301 is used. Has disclosed a universal holder type spray dryer.

In the former, for example, as shown in FIG. 6, an upper plate inclined type atomizer disk 10 which is driven to rotate by a motor 9 is accommodated in a container 8 and a drain pipe 11 is attached to the rotating upper plate inclined type atomizer disk 10. Drainage and hot air tube 1
The hot air from 2 is blown out to efficiently dry the wastewater.

In the latter, for example, as shown in FIG. 7, the heating gas G is supplied from the head side of the container 13 and the waste water M from the nozzle 14 provided on the bottom side of the container 13 is supplied.
Is sprayed, and the wastewater M is brought into direct contact with the heating gas G to dry the wastewater M, thereby generating a particulate product S.

A desulfurization apparatus for treating sulfur contained in exhaust gas by using one of the above-mentioned upper plate inclined type atomizer disk system and universal holder system, for example, as shown in FIG. As shown in the figure, when the exhaust gas from the boiler 15 is treated by the spray dryer 16, the sulfur content is reacted and removed with the supplied alkaline aqueous solution, and then the ash and salts are removed by the dust collector 17, and then the exhaust gas is passed through the chimney 18. A semi-dry desulfurization device that discharges air to the atmosphere is being implemented.

As described above, in a conventional power generation plant or a waste incineration plant, harmful components contained in the exhaust gas and adversely affecting the human body and the like are separated and treated by a combination of mechanical means and chemical means to protect the environment. Had to deal with it.

[0011]

In the conventional evaporating and concentrating means shown in FIG. 5, since gypsum, silica, and insoluble suspended substances become scales and cause problems such as a decrease in heat transfer efficiency, scale components are stored in a container. There is naturally a limit in concentrating the aqueous solution so that it does not adhere to or accumulate on the wall surface, etc., and it is insufficient to precipitate more gypsum as a seed crystal, resulting in inefficient energy consumption. Had become.

In addition, in the conventional evaporation and concentration means, when gypsum as a seed crystal is precipitated from an aqueous solution, silica and other insoluble suspended substances as other scale components are also precipitated at the same time. There were inconveniences and defects such as labor and cost.

Further, in a conventional spray dryer used in a refuse incineration plant, an insoluble suspended substance or the like may block a nozzle portion. For this reason, in order to spray the wastewater, pretreatment is required, and the frequency of its removal and washing is high, and it has not been widely used.

Further, with the recent tightening of drainage standards, it is required to eliminate drainage, and there is a need for an evaporator which does not cause problems such as blockage even in wastewater containing high-concentration scale components. I have.

The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a wastewater treatment apparatus that can effectively treat exhaust gas, wastewater, and the like discharged from an energy generation department or the like at a relatively low cost. With the goal.

[0016]

According to a first aspect of the present invention, there is provided a wastewater treatment apparatus according to the present invention, wherein various types of wastewater are supplied to an inclined upper plate atomizer disk spray dryer and a universal dryer. Evaporation and drying using either one of the nozzle holder type spray dryers to turn harmful components into powder solids.

According to a second aspect of the present invention, there is provided a wastewater treatment apparatus, comprising: SOx of generated exhaust gas
With a desulfurization device that keeps the concentration low, desulfurization wastewater generated from the desulfurization device is evaporated and dried using one of the upper plate inclined type atomizer disk type spray dryer and the universal nozzle holder type spray dryer, The harmful components are made into powder solids.

According to a third aspect of the present invention, there is provided a wastewater treatment apparatus for reducing the NOx concentration of an exhaust gas generated from a combustion apparatus which inputs liquefied natural gas as fuel. A denitration device that suppresses, a heat exchanger that heats air from the atmosphere using steam from the combustion device as a heating source, and a harmful component contained in various wastewaters that are dried with high-temperature air to produce powdered solids As a wastewater treatment device to be supplied to the dust collector, one of an upper plate inclined type atomizer disk type spray dryer and a universal nozzle holder type spray dryer is used, and the upper plate inclined type atomizer disk type spray dryer and the universal nozzle holder are used. Including powdered solids that have been treated in one of Among the exhaust gas, the ash is intended to capture the above dust collector.

According to a fourth aspect of the present invention, there is provided a wastewater treatment apparatus according to the present invention, wherein harmful components contained in various kinds of wastewater supplied by exhaust gas generated from a refuse incinerator are provided. Is used as a wastewater treatment device that is dried into powdered solids and supplied to a dust collector, using one of an upper plate inclined type atomizer disk type spray dryer and a universal nozzle holder type spray dryer. The ash is captured by the dust collector in the exhaust gas containing the powdered solid material that has been treated in one of the atomizer disk type spray dryer and the universal nozzle holder type spray dryer.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a waste water treatment apparatus according to the present invention will be described below with reference to the drawings and reference numerals attached to the drawings.

FIG. 1 is a schematic system diagram showing a first embodiment in which a wastewater treatment apparatus according to the present invention is applied to a power plant using, for example, coal, heavy oil, and orimulsion as fuel.

The waste water treatment apparatus according to the present embodiment includes a waste water purification system 21 for purifying exhaust gas generated from a combustion device 20 such as a boiler or a waste incinerator and waste water discharged from other equipment of a power plant. It is configured to combine a gypsum generation system 22 for generating and recovering gypsum as a product by regenerating lime water supplied to the system 21.

The waste water purification system 21 includes a denitration device 23, an air preheater 24, a dust collector 25, and a desulfurization device 26 in order along the flow of the exhaust gas discharged from the combustion device 20, and the inlet side of the air preheater 24. From the air preheater 2
The blower 28 and the first spray dryer 29 are sequentially arranged along the flow of the exhaust gas in the bypass circuit 27 connected to the outlet side of
And a gypsum separator 30 attached to the desulfurization unit 26.
It has.

Further, the gypsum generating system 22 converts the gypsum using the gypsum water supplied from the gypsum separator 30 of the waste water purification system 21 as a product, with the heat exchanger 31 using steam generated from the combustion device 20 as a heating source. A second spray dryer 32 for generating and collecting is provided.

Each of the first spray dryer 29 and the second spray dryer 32 is either an upper plate inclined type atomizer disk type spray dryer shown in FIG. 6 or a universal nozzle holder type spray dryer shown in FIG. Either one is applied, and various kinds of waste water or steam are evaporated and dried to make harmful components into powder solids.

In the waste water purification system 21 having such a configuration, the exhaust gas generated from the combustion device 20 and having a temperature of about 350 ° C. or higher is subjected to a catalytic action in a denitration device 23 to remove nitrogen oxides NOx. In the preheater 24, the temperature is reduced to, for example, about 150 ° C., and supplied to the dust collector 25. The reason why the exhaust gas is cooled to a temperature of about 150 ° C. by the air preheater 24 is to take account of an acid dew point for preventing corrosion of the dust collector 25.

The exhaust gas supplied to the dust collector 25 is separated into ash and then supplied to a desulfurizer 26 where it reacts with the lime water to remove sulfur and then is discharged from the chimney 33 to the atmosphere. Is done. Note that the dust collector 25 may supply ammonia to the upstream side in order to prevent the generation of acid ash.

An aqueous solution containing calcium sulfate and the like generated by the reaction between the sulfur content of the exhaust gas and lime water in the desulfurizer 26 is supplied to the gypsum separator 30, where boron,
It is separated into solid gypsum and filtered water containing harmful components such as fluorine, heavy metals and ammonia and scale components such as gypsum and silica.

A part of the filtered water separated from the aqueous solution containing calcium sulfate and the like is returned to the desulfurization unit 26 and reused. In particular, in order to prevent the concentration of chlorine, a part of the filtered water is discharged as desulfurization wastewater. .

The desulfurization wastewater containing harmful components such as boron and scale components such as gypsum is supplied to the first spray dryer 29. The chlorine separated by the gypsum separator 30 is blown out of the system because it causes corrosion.

On the other hand, a part of the exhaust gas which has exited from the denitration device 23 is supplied to a first spray dryer 29 through a blower 28 of a bypass circuit 27, where the desulfurization wastewater containing the above-mentioned harmful components such as boron is discharged. And, for example, wastewater from a condensate desalination unit of a power plant, sludge water from a makeup water system, various wastewater such as domestic water are added, and when the temperature of a boron compound, a fluorine compound heavy metal, gypsum, silica or the like is 350 ° C or less, The components that do not evaporate are supplied to the dust collector 25 as a powdery solid, and are captured together with the ash.

On the other hand, in the gypsum producing system 22, high-temperature air from the atmosphere using steam supplied from the combustion device 20 to the heat exchanger 31 as a heating source is supplied to the second spray dryer 32, and the above-described waste water purification system is used. The gypsum water from the gypsum separator 30 is dried, steam generated at that time is supplied to other devices, and the dried gypsum is produced as a product.

As described above, according to the present embodiment, the N
Ox is removed by the denitration device 23, and harmful components and scale components contained in the wastewater are evaporated by the first spray dryer 29.
Wastewater purification system 2 which is dried to turn harmful components into powdery solids 2
1 and a gypsum generation system 22 for generating and recovering gypsum as a product in a second spray dryer 32 at the time of desulfurization of exhaust gas by using a second spray dryer 32, so that multipurpose use is achieved. The wastewater can be treated at a relatively low cost, and harmful components and the like contained in the wastewater can be reliably removed to sufficiently cope with environmental conservation.

FIG. 2 is a schematic system diagram showing a second embodiment in which the wastewater treatment apparatus according to the present invention is applied to a power plant using, for example, LNG (liquefied natural gas) as fuel.
The same parts as those in the first embodiment are denoted by the same reference numerals.

In this embodiment, the exhaust gas treatment system is not provided with a dust collector because LNG, which is clean energy, is used as the fuel to be supplied to the combustion device 20. Or
In the exhaust gas generated from the combustion device 20, NOx is processed by the denitration device 23 and the air preheater 24, and is discharged from the chimney 33 to the atmosphere. On the premise of such a point, the present embodiment considers that various kinds of wastewater such as wastewater from a condensate desalination device of a power plant and sludge water and domestic wastewater from a makeup water system contain more ammonia. In addition, a dust collector 25 and an ammonia processing unit 35 are provided on the outlet side of the spray dryer 34.

As the spray dryer 34, for example, one of an upper plate inclined type atomizer disk type spray dryer shown in FIG. 6 and a universal nozzle holder type spray dryer shown in FIG. 7 is applied. As in the first embodiment, high-temperature air after heat exchange between steam supplied from the combustion device 20 to the heat exchanger 31 and the atmosphere is used as a drying and heating source for harmful components and scale components contained in the wastewater. .

Further, the spray dryer 34 dries harmful components and scale components contained in various kinds of wastewater into powdery solids, captures ash in the powdery solids with the dust collector 25, and converts ammonia into ammonia. After being processed in the processing section, the residue is discharged outside the vessel.

As described above, in the present embodiment, the combustion device 20
Of the exhaust gas generated from the waste gas, NOx is processed by the denitration device 23, and harmful components and scale components contained in various wastewaters are dried by the spray dryer 34 into powdery solids, which are further contained in various wastewaters. Since ammonia is treated in the ammonia treatment section 35, harmful components and the like can be reliably removed, and sufficient measures can be taken for environmental conservation.

FIG. 3 is a schematic system diagram showing a third embodiment in which the wastewater treatment apparatus according to the present invention is applied to a power plant using, for example, coal or heavy oil as fuel. The same parts as those in the first embodiment are denoted by the same reference numerals.

In this embodiment, the harmful components and scale components contained in the various kinds of wastewater are dried by the spray dryer 36 into powdery solids. Another dust collector 37 is provided on the side, and is separately provided from the dust collector 25 provided on the outlet side of the air preheater 24. In addition, other configurations are
Since it is the same as the first embodiment, the description is omitted. As the spray dryer 36, any one of an upper plate inclined type atomizer disk type spray dryer and a universal nozzle holder type spray dryer is applied.

As described above, in this embodiment, another dust collector 37 is provided at the outlet side of the spray dryer 36, and excessive ash generated from the spray dryer 36 is collected by the dust collector 37.
Therefore, the drainage purification system 21 such as the spray dryer 36, the desulfurization device 26, and the gypsum separator 30 can be stably operated.

FIG. 4 is a schematic system diagram showing a fourth embodiment in which the wastewater treatment apparatus according to the present invention is applied to, for example, a waste incineration plant. The same parts as those in the first embodiment are denoted by the same reference numerals.

In the present embodiment, the spray dryer 3 is sequentially arranged along the flow of the exhaust gas generated from the waste incinerator 38.
9. A dust collector 25, an exhaust gas treatment device 40, a drainage circulation system 41 for supplying waste water from the exhaust gas treatment device 40 to the spray dryer 39, and a chimney 33 are provided. Various drainage such as drainage and miscellaneous drainage in plant and drainage circulation system 4
The wastewater supplied from 1 is added to cool the exhaust gas to keep the dioxin concentration low, and harmful components and scale components contained in various wastewaters are dried to a powdery solid, which is contained in the solid. The ash is captured by the dust collector 25, and slaked lime water is further added by the exhaust gas treatment device 40 to remove chlorine and the like contained in the exhaust gas, and the exhaust gas is released from the chimney 33 to the atmosphere. Spray dryer 3 through drainage circulation system 41
9, and reused for lowering the concentration of dioxin and for solidifying powdery solids such as harmful components. As the spray dryer 39, any one of an upper plate inclined type atomizer disk type spray dryer and a universal nozzle holder type spray dryer is applied.

As described above, the present embodiment includes the spray dryer 39, the dust collector 25, and the exhaust gas treatment device 40,
Dioxin concentration generated from exhaust gas is kept low, harmful components and scale components contained in various kinds of supplied wastewater are converted into powdery solids to make them harmless, and the plant is simplified, so sufficient for environmental conservation. It is possible to install a waste incineration plant even in an urban area where it is difficult to secure large land.

[0045]

As described above, the wastewater treatment apparatus according to the present invention lowers the concentration of NOx generated from exhaust gas, reacts and removes sulfur, and also removes harmful components contained in various supplied wastewater. Since a means for converting the scale component into a powdery solid is provided, it is possible to sufficiently cope with environmental conservation.

[Brief description of the drawings]

FIG. 1 is a schematic system diagram showing a first embodiment of a wastewater treatment device according to the present invention.

FIG. 2 is a schematic system diagram showing a second embodiment of the wastewater treatment device according to the present invention.

FIG. 3 is a schematic system diagram showing a third embodiment of the wastewater treatment apparatus according to the present invention.

FIG. 4 is a schematic system diagram showing a fourth embodiment of the wastewater treatment device according to the present invention.

FIG. 5 is a schematic system diagram showing a conventional desulfurization wastewater treatment device.

FIG. 6 is a conceptual diagram showing a conventional spray dryer.

FIG. 7 is a conceptual diagram showing another conventional spray dryer.

FIG. 8 is a schematic system diagram showing a conventional refuse incineration plant.

[Description of Signs] 1 storage tank 2 evaporator 3 heater 4 sedimentation tank 5 kneader 6 storage tank 7 premixer 8 container 9 motor 10 upper plate inclined type atomizer disk 11 drain pipe 12 hot air pipe 13 container 14 nozzle 15 boiler 16 spray Dryer 17 Dust collector 18 Chimney 20 Combustion device 21 Drainage purification system 22 Gypsum generation system 23 Denitration device 24 Air preheater 25 Dust collector 26 Denitration device 27 Bypass circuit 28 Blower 29 First spray dryer 30 Gypsum separator 31 Heat exchanger 32 Second spray Dryer 33 Chimney 34 Spray dryer 35 Ammonia treatment unit 36 Spray dryer 37 Dust collector 38 Waste incinerator 39 Spray dryer 40 Exhaust gas treatment device 41 Drainage circulation system

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tetsuo Sakamoto 5-7 Kamata, Ota-ku, Tokyo F-term in Sakamoto Giken Co., Ltd. 4D002 AA02 AA12 AA13 AA21 BA02 BA14 CA01 DA05 DA12 DA16 EA08 EA12 EA13 GA03 GB03 4D034 AA14 BA01 CA19 4D048 AA02 AA06 AA08 AA11 AC10 CC26 CC39 CD03 CD08 CD10

Claims (8)

[Claims] 1. While reducing the NOx concentration of exhaust gas generated from a boiler, and adding lime water to the exhaust gas to remove sulfur, harmful components contained in various wastewaters are dried to form powdery solids. A wastewater treatment system, comprising: a wastewater purification system for performing gypsum production; and a gypsum generation system for drying gypsum water generated when the limewater is added to the exhaust gas to produce gypsum. 2. The wastewater purification system includes a denitration device that suppresses NOx concentration of exhaust gas generated from a boiler, a dust collector that captures ash contained in exhaust gas that has passed through an air preheater, and lime water that is injected into the exhaust gas. A desulfurization device that generates sulfur compounds, a gypsum separator that separates wastewater from the desulfurization device into filtered water, desulfurization wastewater, and gypsum water, and a bypass circuit that connects the inlet side and the outlet side of the air preheater to each other It is provided with a spray dryer for drying harmful components contained in desulfurization wastewater and various wastewater supplied from the gypsum separator to produce a powdery solid and supply the dust collector to the dust collector. The wastewater treatment device according to claim 1. 3. The spray dryer, on its outlet side,
3. The wastewater treatment device according to claim 2, wherein another dust collector is provided at an intermediate portion between the dust collector and the inlet side. 4. The wastewater treatment apparatus according to claim 2, wherein the bypass circuit includes a blower on an inlet side of the spray drier. 5. A gypsum generating system includes: a spray dryer for drying gypsum water from a gypsum separator of a wastewater purification system to generate gypsum; a heating medium supplied to the spray dryer; and a heating medium supplied from a boiler. The wastewater treatment apparatus according to claim 1, further comprising: a heat exchanger heated by steam. 6. A denitration device for suppressing the NOx concentration of exhaust gas generated from a boiler into which liquefied natural gas is injected as fuel, a heat exchanger for heating air from the atmosphere using steam from the boiler as a heating source, A spray dryer that dries harmful components contained in various kinds of wastewater with high-temperature air to produce a powdery solid and supplies it to a dust collector; and, from the exhaust gas containing the powdery solid from the spray dryer, removes ash from the dust collector. A wastewater treatment apparatus, comprising: an ammonia treatment unit for removing ammonia contained in exhaust gas while trapping the wastewater in the exhaust gas. 7. A spray drier which suppresses dioxin concentration in exhaust gas generated from a refuse incinerator, dries harmful components contained in various kinds of supplied waste water to form powder solids, and supplies the solids to a dust collector. Of the exhaust gas containing powdery solids from this spray dryer,
A wastewater treatment device comprising: an exhaust gas treatment device that captures ash by the dust collector and that removes lime by adding slaked lime water to chlorine contained in the exhaust gas. 8. The wastewater treatment apparatus according to claim 7, wherein the wastewater treatment apparatus includes a wastewater circulation system that supplies generated wastewater to a spray dryer when slaked lime water is supplied to the waste gas.