KR101933825B1 - System for a disposal of a waste water - Google Patents

Abstract

The present invention relates to a wastewater treatment system, comprising a slurry stripper portion provided to separate at least carbon dioxide and calcium ions from foreign substances contained in wastewater, and a slurry stripper portion disposed between the slurry stripper portion and the wastewater line, And a crystallization unit that reacts carbon dioxide and calcium ions flowing through the wastewater line in advance to form crystals so as to prevent formation of crystals of calcium ions. According to the present invention, calcium ions and carbon dioxide are precrystallized It is possible to prevent clogging or breakage of the waste water line due to crystallization on the waste water line.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste water treatment system,

The present invention relates to a wastewater treatment system, and more particularly to a wastewater treatment system, which comprises calcium ion and carbon dioxide precrystallized to produce a calcite structure that can be easily removed as a scale to prevent clogging of the wastewater line due to crystallization on the wastewater line And the like.

The wastewater treatment system is a system for purifying wastewater containing various foreign substances discharged from industrial facilities and discharging the wastewater into a natural environment or recycling the wastewater into industrial water.

1 shows an example of a conventional wastewater treatment system. The system shown in FIG. 1 has a structure for removing such foreign substances by being disposed in an industrial facility in which carbon dioxide and calcium ions are frequently used.

1, the conventional wastewater treatment system includes a wastewater line 41 through which wastewater containing a relatively large amount of carbon dioxide flows among the foreign substances contained in the wastewater, and wastewater containing a relatively large amount of calcium ions among the foreign substances contained in wastewater A wastewater line 40 consisting of a wastewater line 42 is disposed and connected to vessels 31 and 34, respectively.

That is, the wastewater line 41 is connected to the vessel 31 to send wastewater containing a large amount of carbon dioxide, and the wastewater line 42 is connected to the vessel 34 to send wastewater containing a large amount of calcium ions. The reason why the carbon dioxide and the calcium ion are separately separated and sent to the separate vessel is to prevent the carbon dioxide and the calcium ion from reacting and crystallizing.

If calcium carbonate (CaCO ₃ ) is formed by the reaction of carbon dioxide (CO ₂ ) and calcium ions (Ca ^{2 +} ) in the piping, such calcium carbonate crystals accumulate to block the piping, It can lead to breakage. Therefore, it is necessary to separate and treat wastewater so that carbon dioxide and calcium ions do not react with each other.

Part of the wastewater flowing into the vessels 31 and 34 spontaneously evaporates through the upper portions of the vessels 31 and 34 and is cooled by the blower 93 through the gas pipes 95 and 97 and then flows through the classification tank 92 And the remaining wastewater flows into the slurry stripper 20 by the pumps 32 and 35 disposed on the wastewater pipes 33 and 36 connected through the lower portions of the vessels 31 and 34. A gas such as carbon dioxide which is not liquefied by the blower 93 and a liquid such as water liquefied by the blower 93 coexist in the inside of the fractionation tank 92.

In the slurry stripper 20, a wastewater pipe 33 is connected to the upper side, and relatively rich wastewater with carbon dioxide is sprayed. In the middle side, wastewater having a relatively rich calcium ion is sprayed because the wastewater is connected to the wastewater pipe 36.

At this time, steam is supplied from the steam device 25 to the lower side of the slurry stripper 20, whereby carbon dioxide is evaporated and discharged through the gas pipe 96 connected to the upper end of the slurry stripper 20. Here, the water in the liquid coexisting in the separation tank 92 flows into the upper part of the slurry stripper 20 through the pump 94 and is injected again. Whereby the wastewater is diluted.

The calcium ions are discharged to the piping connected to the lower end of the slurry stripper 20 and then moved to the purification facility 28 by the pump 27 and finally purified.

However, in the conventional wastewater treatment system, carbon dioxide and calcium ions can be separated to treat wastewater to some extent to prevent crystallization. However, the wastewater supplied to each wastewater line 41, And it was not completely separated even on the slurry stripper, so that carbon dioxide and calcium ions reacted to produce calcium carbonate crystals having an aragonite crystal structure. In addition, depending on the temperature and pressure conditions on the piping, calcium ion becomes an agglomerate of calcium by the action of electrons, which is also a factor blocking the piping.

This accumulates in the piping of the equipment and blocks the piping, which consumes a considerable amount of the maintenance cost, and causes the work load of the cleaning worker.

Korean Patent Publication No. 10-2013-0028644

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art as described above, and it is an object of the present invention to provide a calcite structure that can be easily removed as a scale by precalcifying calcium ions and carbon dioxide, Thereby preventing clogging or breakage of the waste water line caused by the waste water.

According to an aspect of the present invention, there is provided a wastewater treatment system comprising: a slurry stripper unit provided to separate at least carbon dioxide and calcium ions from foreign substances contained in wastewater; a slurry stripper unit disposed between the slurry stripper unit and the wastewater line, And a crystallization unit for causing the carbon dioxide and calcium ions flowing through the wastewater line to react with each other in advance so as to form crystals so that formation of crystals of carbon dioxide and calcium ions in the slurry stripper unit is prevented.

In addition, in the embodiment of the present invention, the crystals generated in the crystallization part may be a calcite structure.

According to an embodiment of the present invention, the wastewater line is divided into a first wastewater line and a second wastewater line, wherein the first wastewater line is a line through which wastewater containing a relatively large amount of carbon dioxide is flowing than the first wastewater line, And the second wastewater line is a line through which wastewater containing a relatively larger amount of calcium ions flows than the first wastewater line and can be connected to the crystallization part below the first wastewater line.

In addition, in the embodiment of the present invention, the drainage line discharged from the crystallization section is divided into a first drainage line and a second drainage line, the first drainage line is connected to the upper side of the slurry stripper section from above the crystallization section, And the second drainage line may be connected to a lower side of the slurry stripper portion below the crystallization portion.

In an embodiment of the present invention, the filtration unit may further include a filtration unit disposed on the second drain line so that the crystallized calcium ions are filtered by the crystallization unit.

In addition, in the embodiment of the present invention, the filtration unit may be a nanofiltration membrane or an ion exchange filtration membrane that filters only bivalent ions.

In addition, the embodiment of the present invention may further include a determination system rejection disposed at the lower end of the crystallization unit to remove the crystals generated in the crystallization unit.

Further, in the embodiment of the present invention, the decision rejection may be a hydrocyclone or a filter press.

In an embodiment of the present invention, the apparatus may further include an acidity adjusting unit connected to the wastewater line or the drain line, respectively, for allowing the calcium ion contained in the wastewater line or the wastewater flowing through the drain line to remain in an ionic state .

Further, in the embodiment of the present invention, the apparatus further includes a gas discharging portion connected to the upper portion of the crystallizing portion and the upper portion of the slurry stripper portion, respectively, so as to remove at least gas containing at least carbon dioxide discharged from the crystallizing portion or the slurry stripper portion can do.

Further, in an embodiment of the present invention, the apparatus may further include a steam supply unit connected to a lower portion of the slurry stripper unit and spraying steam into the slurry stripper unit to evaporate at least carbon dioxide contained in the wastewater.

According to the present invention, since calcium ions and carbon dioxide are reacted in advance and crystallized into a calcite structure that can be easily removed as a scale due to weak cohesive force, the calcium ions are crystallized by reaction in a piping or a purifier of a wastewater line, It is possible to prevent the line from being blocked or broken.

After the pre-crystallization step, a NF membrane (NF membrane) and an ion-exchange filtration membrane (ion exchange filtration membrane) for removing secondary ions of the calcium ions contained in the wastewater are disposed on the wastewater line It is possible to prevent clogging or breakage of the wastewater line by lowering the crystallization ratio with carbon dioxide.

In addition, a pH adjustment line is locally connected to the wastewater line to prevent the calcium ion from being clogged or broken by the calcium crystals by keeping the ion state without lumping the calcium ion.

This ultimately enables the extension of the service life of the wastewater treatment facilities of the industrial facilities and the reduction of the maintenance costs, and the efficient treatment of environmental pollution and facility operation through smooth wastewater treatment can be achieved.

1 shows a conventional wastewater treatment system;
2 illustrates an embodiment of a wastewater treatment system of the present invention.

Hereinafter, preferred embodiments of a wastewater treatment system according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a view showing an embodiment of a wastewater treatment system according to the present invention.

2, the embodiment of the wastewater treatment system of the present invention includes a wastewater line, a crystallization unit 300, a drainage line 500, a slurry stripper unit 200, an acidity control unit 800, and a gas discharge unit 900 And the like.

The wastewater line 400 may be a piping or facility device connected to an industrial facility and flowing wastewater discharged from an industrial facility and may be divided into a first wastewater line 410 and a second wastewater line 420 . The first wastewater line 410 may be a line through which wastewater containing a relatively large amount of carbon dioxide flows. That is, the wastewater contains various substances, and the first wastewater line 410 may be a pipe or a facility for flowing waste water having a relatively large amount of carbon dioxide compared to other materials.

The second wastewater line 420 may be a line through which wastewater containing a relatively large amount of calcium ions flows. Also, the wastewater contains various substances, and the second wastewater line 420 may be a piping or a facility for flowing wastewater in which a relatively large amount of calcium ions are dissolved compared to other materials.

Here, the term 'relative' means that the carbon dioxide concentration of the wastewater flowing through the first wastewater line 410 is higher than the carbon dioxide concentration of the wastewater flowing through the second wastewater line 420, 420 may be interpreted to mean that the calcium ion concentration of the wastewater flowing through the first wastewater line 410 is higher than that of the wastewater flowing through the first wastewater line 410. In the embodiment of the present invention, the meaning of relative can be interpreted as the latter.

The first wastewater line 410 may be connected to the crystallization unit 300 and the second wastewater line 420 may be connected to the crystallization unit 300 under the first wastewater line 410 .

The crystallizing unit 300 is disposed between the slurry stripper unit 200 and the wastewater line 400 and is disposed in the slurry stripper unit 200 to prevent the formation of crystals of carbon dioxide and calcium ions inside the slurry stripper unit 200, It is possible to perform a function of reacting carbon dioxide and calcium ions flowing through the reaction chamber 400 in advance to form a crystalline body.

The first wastewater line 410 is connected to the first injection nozzle 320 disposed on the upper part of the vessel 310 constituting the crystallization unit 300 and the carbon dioxide is supplied into the crystallization unit 300 in a large amount So that the waste water contained therein is sprayed.

The second wastewater line 420 is connected to a second injection nozzle 330 disposed at an upper portion of the vessel 310 and injects wastewater containing a large amount of calcium ions into the crystallization unit 300.

The wastewater containing the injected carbon dioxide and calcium ions is mixed in the mixing part 350 and a crystal action between carbon dioxide (CO ₂ ) and calcium ion (Ca ²⁺ ) occurs. As a result, calcium carbonate (CaCO ₃ ) crystals having a calcite structure are produced.

Conventionally, crystals having aragonite (needle-shaped crystal) structure are randomly generated by the interaction between carbon dioxide and calcium ions in the course of wastewater flowing in piping or equipment. The aragonite structure is hard and cohesive so that when crystals are formed, they accumulate inside the piping or equipment, obstructing the flow of the wastewater or blocking the piping or equipment. As a result, the wastewater treatment is not smooth and excessive maintenance costs are incurred.

In the embodiment of the present invention, the slurry stripper unit 200 is formed with crystals having a specific structure in advance before the wastewater flows in order to prevent such a random crystallization phenomenon. That is, carbon dioxide and calcium ions are reacted with each other at a proper temperature and pressure condition to produce a calcite structure in the mixing part 350 to produce a calcium carbonate crystal having a calcite (hexagonal) structure. In general, it may be in a high-temperature, high-pressure state to increase the reactivity.

The calcite crystal structure has a larger structure and spherical structure than the aragonite crystal structure, and has a weak cohesive force and tends to be easily broken. For reference, aragonite has a hardness of about 3.5 to 4, a specific gravity of 2.9, a hardness of about 3 and a specific gravity of 2.6 to 2.8. That is, the calcite structure is lower than that of the aragonite structure.

When a calcium carbonate crystal having a calcite crystal structure is produced, it precipitates to the lower side of the mixing portion 350 due to its specific gravity. A filter 370 is disposed below the mixing unit 350 and the calcium carbonate crystals filtered by the filter 370 are removed by the crystal structure rejection unit 700.

The crystallization rejection unit 700 is interlocked with the crystallization unit 300 and removes and removes calcium carbonate crystals through a hydro cyclone or a filter press method.

The drainage line 500 may be provided to flow the wastewater discharged from the crystallization unit 300 to the slurry stripper unit 200 connected to the crystallization unit 300. The drainage line 500 may be divided into a first drainage line 510 and a second drainage line 530. The first drainage line 510 is formed on the upper side of the crystallization part 300, And the second drainage line 530 may be connected to the lower side of the crystallization unit 300 and the lower side of the slurry stripper unit 200.

Specifically, the first drain line 510 is connected to an upper portion of the mixing unit 350 constituting the crystallizing unit 300, and relatively less foreign matter than the wastewater flowing through the second drain line 530 It may be a pipe through which wastewater flows. In particular, there may be relatively few unreacted calcium ions. A pump 520 may be disposed on the first drain line 510 to smooth the flow of wastewater to the slurry stripper unit 200.

The second drainage line 530 is connected to the lower end of the filter 370 constituting the crystallization unit 300 so that wastewater containing a relatively large amount of foreign matter than the wastewater flowing through the first wastewater line 410 flows It can be piping. In particular, it may contain a relatively large amount of unreacted calcium ions. The difference in degree of purification between the first wastewater line 410 and the second wastewater line 420 can be attributed to the tendency that the foreign matter is precipitated by gravity. A pump 540 is also disposed on the second drain line 530 to smooth the flow of wastewater to the slurry stripper unit 200.

Referring again to FIG. 2, in the embodiment of the present invention, the filtration unit 600 may be additionally disposed on the second drainage line 530. The filtration unit 600 functions to remove uncrystallized calcium ions from the crystallization unit 300. The filtration unit 600 may be a NF membrane, an ion-exchange filtration membrane, or the like that filters only bivalent ions.

That is, the calcium ion (Ca ^{2 +} ) is a bivalent ion, and the bivalent ion reaction material is contained in the filtration unit 600 to thereby remove calcium ions. This makes it possible to further lower the calcium ion concentration in the wastewater flowing into the slurry stripper unit 200 through the second drainage line 530, thereby further suppressing the arbitrary crystal generation rate.

Next, the slurry stripper 200 may be provided to finally separate at least carbon dioxide and calcium ions from the foreign substances contained in the wastewater. The first drain line 510 is connected to an injection nozzle 220 disposed on the upper side of the slurry stripper 200 to discharge wastewater and the second drain line 530 is connected to the slurry stripper 200 And the wastewater is sprayed thereon.

At this time, a steam supply unit 250 may be connected to a lower portion of the slurry stripper unit 200. The steam supply unit 250 may inject high-temperature steam into the slurry stripper 200 to evaporate at least carbon dioxide contained in the wastewater. That is, when the high temperature steam supplied from the steam supply unit 250 is sprayed from the diffusion nozzle 240, the carbon dioxide remaining unreacted in the crystallization unit 300 is evaporated to contact the upper portion of the slurry stripper unit 200 . Of course, water that has evaporated in addition to carbon dioxide can also be included.

The unreacted calcium ions in the crystallizing part 300 or the calcium ions left unfiltered in the filtration part 600 in the embodiment of the present invention are moved together with the waste water to the lower part of the slurry stripper part 200 . The lower part of the slurry stripper part 200 is connected to the purifying part 280 through a pipe, and various foreign substances are finally purified and discharged to the outside by the purifying part 280. The purified water passing through the purifying unit 280 may be supplied to the third injection nozzle 340 of the crystallizing unit 300 through the purified water supplying unit 290. In this case, the purified water may be mixed with the wastewater flowing from the first wastewater line 410 and the second wastewater line 420 to dilute the concentration of foreign matter or the concentration of carbon dioxide and calcium ions in the wastewater.

The gas exhaust part 900 is connected to the upper part of the crystallizing part 300 and the upper part of the slurry stripper part 200 and is discharged from the crystallizing part 300 or the slurry stripper part 200 It may be provided that at least gas containing carbon dioxide is removed.

Specifically, the upper part of the crystallizing part 300 is connected to the fractionating tank 920 through a first gas line 950. In the crystallizing part 300, a gas such as carbon dioxide or water vapor, May be stored in the fractionation tank 920 via the first gas line 950.

The upper part of the slurry stripper part 200 is connected to the branching tank 920 through a second gas line 960. The upper part of the slurry stripper part 200 is connected to the branching tank 920 at a high temperature Gas such as carbon dioxide, water vapor, or the like vaporized by the steam can be stored in the fractionation tank 920 through the second gas line 960.

At this time, an air cooling unit 930 may be disposed on the line connecting the first gas line 950 to the second gas line 960 and the separation tank 920, and the air cooling unit 930 The water vapor can be cooled and become liquid. Since carbon dioxide has a liquefaction temperature of -78.5 ° C under atmospheric pressure (1 atm), it is not liquefied only by the fan operation of the air cooling unit 930. The water in the liquid state also flows into the fractionation tank 920.

The upper part of the fractionation tank 920 is connected to the atmosphere 910 and the lower part of the fractionation tank 920 is connected to the upper side of the slurry stripper part 200 through a pipe. The carbon dioxide passes through the upper portion of the fractionation tank 920 and is discharged to the atmosphere 910. The water passes through the lower portion of the fractionation tank 920 and is discharged to the upper side of the sandy slurry stripper portion 200 by the pump 940 And then supplied again. Then injected into the injection nozzle 210 and used to circulate the wastewater.

The pH controller 800 is connected to the wastewater line 400 or the drain line 500 and the calcium ion contained in the wastewater flowing through the wastewater line 400 or the drain line 500 Ionic < / RTI > state. Of course, it is not necessarily limited to calcium ions, and may be applied to maintain ionic states of other substances depending on the application environment.

Specifically, the acidic solution diluted with sulfuric acid, hydrochloric acid, nitric acid, or the like can be supplied to each of the acid supply pipes by the pump 820 at the pore supply portion 810 of the acidity adjusting portion 800. First, the first acid feed pipe 830 may be connected to the first waste water line 410. The acidic liquid can be supplied or blocked to the first waste water line 410 by the control valve. The second acid supply pipe 940 may be connected to the second waste water line 420. The acidic liquid can also be supplied or shut off to the second waste water line 420 by the control valve.

The third acid supply pipe 860 may be connected to the first drain line 510 and may maintain the ionic state of the calcium material in the waste water discharged from the crystallization unit 300. The fourth acid supply pipe may be connected to the second drain line 530 and may maintain the ionic state of the calcium material in the waste water discharged from the crystallization unit 300.

The third acid supply pipe 860 and the fourth acid supply pipe 850 may be connected to the lower connection pipe of the slurry stripper 200 by a bypass control valve. This is to ensure that the calcium material contained in the wastewater discharged through the lower portion of the slurry stripper 200 maintains the ion state. The acid liquid can be selectively supplied to the lower connecting pipe of the slurry stripper unit 200 by the bypass control valve.

That is, the acidity controller 800 functions to maintain the pH on the piping constant so as not to react with carbon dioxide and to prevent the remaining calcium ions in the wastewater from solidifying into a calcium mass. At this time, the pH on the piping may be about 5.5 to 6.5.

In the embodiment of the present invention, calcium ions and carbon dioxide are precalculated and removed as a scale through the above-described constitution and operation, and the uncrystallized calcium material is adjusted to maintain the ionic state, It is possible to suppress the clogging and breakage in the equipment and the like.

The above description is only a specific example of the wastewater treatment system.

Therefore, it should be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. do.

100: wastewater treatment system 200: slurry stripper part
250: steam supply unit 280:
300: Crystallizer 370: Filter
400: wastewater line 410: first wastewater line
420: Second wastewater line 500: Drain line
510: first drain line 530: second drain line
600: Filtration unit 700: Decision system refusal
800: Acidity regulating part 900: Gas discharging part

Claims (11)

A slurry stripper unit provided to separate at least carbon dioxide and calcium ions from foreign substances contained in wastewater;
And carbon dioxide and calcium ions flowing through the wastewater line are reacted in advance to form a crystal body so as to prevent the formation of crystals of carbon dioxide and calcium ions in the slurry stripper portion, which is disposed between the slurry stripper portion and the wastewater line A crystallization part; And
A drain line connected between the crystallizing section and the slurry stripper section and provided to flow wastewater discharged from the crystallizing section to the slurry stripper section; And
And a filtration unit disposed on the drain line so that the uncrystallized calcium ions are filtered by the crystallization unit,
Wherein the drainage line discharged from the crystallization section is divided into a first drainage line and a second drainage line, the first drainage line is connected to the upper side of the slurry stripper section from above the crystallization section, Is connected to the lower side of the slurry stripper part from below the part.
The method according to claim 1,
Characterized in that the crystals produced in the crystallization section are calcite structures.
The method according to claim 1,
Wherein the filtration unit is a nanofiltration membrane or an ion exchange filtration membrane for filtering only divalent ions.
The method of claim 3,
And a determination system disposed at a lower end of the crystallization unit so as to remove the crystals generated in the crystallization unit.
5. The method of claim 4,
Wherein the determination system rejection is a hydrocyclone or a filter press.
The method according to claim 1,
And an acidity controller connected to the wastewater line or the drainage line, respectively, for controlling the calcium ion contained in the wastewater line or the wastewater flowing through the drainage line to remain in an ionic state.
The method according to claim 6,
The wastewater line is divided into a first wastewater line and a second wastewater line,
The acid-
A first acid supply pipe connected to the first waste water line;
A second acid supply line connected to the second waste water line;
A third acid supply pipe connected to the first drain line and connected to the lower connection pipe of the slurry stripper unit by a bypass control valve; And
A fourth acid supply pipe connected to the second drain line and connected to the lower connection pipe of the slurry stripper section by a bypass control valve,
Wherein the waste water treatment system comprises:
The method according to claim 1,
And a gas discharge portion connected to the upper portion of the crystallization portion and the upper portion of the slurry stripper portion and provided to remove at least gas containing at least carbon dioxide discharged from the crystallization portion or the slurry stripper portion, Processing system.
9. The method of claim 8,
The gas-
A fractionation tank connected to an upper part of the crystallization part by a first gas line and connected to an upper part of the slurry stripper part by a second gas line; And
An air cooling unit disposed on a line connected to the first gas line, the second gas line, and the separation tank;
Further comprising: a control unit for controlling the wastewater treatment system.
The method according to claim 1,
And a steam supply unit connected to a lower portion of the slurry stripper unit and spraying steam into the slurry stripper unit to evaporate at least carbon dioxide contained in the wastewater.
The method of claim 1, wherein
A purifier connected to a lower portion of the slurry stripper and removing foreign matter from the wastewater; And
A purified water supply unit connected between the purification unit and the crystallization unit and supplied with purified water from the purification unit and supplying the purified water to the crystallization unit;
Further comprising: a control unit for controlling the wastewater treatment system.

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