KR101989986B1 - Wet Scrubber Tower with function of Humidity Control and a method for purifying using the same - Google Patents

Abstract

The present invention relates to a wet scrubbing tower to which a humidity control function is added and a waste gas purifying method using the same. More specifically, the present invention relates to a scrubbing column main body 200 having a predetermined size and shape, And a waste gas inlet pipe (100) for supplying waste gas. A humidity adjusting unit for adjusting the humidity of the waste gas introduced into the waste gas inlet pipe (100) And a method for purifying waste gas using the same.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet scrubbing tower having a humidity control function and a method for purifying waste gas using the same,

The present invention relates to a wet scrubbing tower having a humidity control function and a method for purifying waste gas using the same. More particularly, the present invention relates to a wet scrubbing tower having a humidity control function, The present invention also relates to a wet scrubbing tower having a humidity control function capable of reducing a treatment cost and a waste gas purification method using the same.

Various pollutants are generated in the process of producing various devices, equipment and raw materials. For example, a cleaning and etching process is required to manufacture semiconductors. In these processes, organic solvents such as acetone, alcohols, monoethanolamine, TCE, methyl chloride, acetic acid, and various thinners are used , Strong acids such as sulfuric acid, nitric acid, hydrofluoric acid and hydrochloric acid, ammonia water, and ammonium fluoride. In the photolithography process, an organic compound, Photo Resist, HMDS, acetone, and an adhesion improver such as a thinner are used. In the plating process, an alcohol-based thinner or isopropyl alcohol (IPA) is used as an organic solvent.

If these pollutants are not removed properly and they are released into the atmosphere, they exist as substances that must be discharged below the emission limit or not discharged to the atmosphere at all because they destroy ecosystems including humans.

Generally, the air pollutant as described above is generally introduced into a wet scrubbing tower, and then sprayed or removed by water or passed through the inside of an adsorption tower to adsorb and remove the air pollutants. That is, a nozzle for spraying a cleaning solution is provided in an inlet portion of the wet scrubbing column, and the nozzle injects droplets of about 500 to 1000 μm.

However, in order to increase the removal efficiency of the pollutants, it is common to use excessive amount of water or washing liquid sprayed from the washing tower. However, since only the treatment cost is increased, satisfactory removal efficiency can not be obtained, The case is frequent.

Particularly, in factories that produce large quantities of water-soluble inorganic salts such as ammonium nitrate, ammonium sulfate, urea, calcium nitrate, potassium nitrate, ammonium phosphate, and complex fertilizers containing the same, ultrafine particles of less than 1 μm are produced as byproducts, It is very difficult to remove to a satisfactory level with the wet cleaning tower method.

Korean Patent Publication No. 2009-0108369 Korean Patent Publication No. 2011-0102277

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a wet scrubbing tower and a scrubbing method that can reduce the treatment cost while improving the removal efficiency of air pollutants.

Another object of the present invention is to provide a wet cleaning tower and a cleaning method that can effectively remove air pollutants from ultrafine particles.

In order to solve the above problems, the wet scrubbing tower of the present invention includes a scrubbing column main body 200 having a predetermined size and shape and a waste gas inlet pipe 100 for supplying waste gas to the scrubbing column main body 200 A predetermined space in the waste gas inlet pipe 100 is provided with a humidity controller for controlling the humidity of the waste gas.

Here, the humidity controller may include a first spray nozzle 111 for spraying a cleaning liquid, and the first spray nozzle 111 may spray droplets having a diameter of 5 to 50 μm.

It is also preferable to spray droplets so that the relative humidity is maintained at 40% or more.

In addition, the waste gas inlet pipe 100 is preferably provided with a waste gas inlet 101 opened at one side so as to allow the waste gas to be purified to flow therein, and the other side is bent at a predetermined angle to communicate with the cleaning column body 200.

The humidity controller may further include a first humidity sensor (H-1) for measuring the humidity of the waste gas flowing into the waste gas inlet pipe (100) near the waste gas inlet (101).

It is preferable that the humidity controller further includes a first temperature sensor T-1 for measuring the temperature of the waste gas passing through the waste gas inlet pipe 100 near the waste gas inlet 101.

Further, it is preferable that a second injection nozzle 131 is further provided on the first injection nozzle 111.

Further, it is preferable that a third injection nozzle 141 is further provided on the second injection nozzle 131, and steam is sprayed to the third injection nozzle 141.

The waste gas may be a waste gas generated in the course of manufacturing any one or more of water-soluble inorganic salts such as ammonium nitrate, ammonium sulfate, urea, calcium nitrate, potassium nitrate, ammonium phosphate, and complex fertilizers containing the same.

The waste gas purifying method according to the present invention is characterized by including the step of introducing the waste gas into the wet scrubbing column, the measurement of the humidity of the waste gas, and the step of spraying the cleaning liquid so that the humidity of the waste gas falls within a predetermined range.

Here, in the step of spraying the cleaning liquid, it is preferable to spray the cleaning liquid so that the relative humidity becomes 40% or more.

According to the wet scrubbing column and the waste gas purifying method of the present invention, there is an advantage that the efficiency of removing contaminants can be improved by controlling the humidity of the waste gas.

Further, according to the wet scrubbing column and the waste gas scrubbing method of the present invention, it is possible to reduce the injection amount of the scrubbing liquid and to reduce the power ratio.

Furthermore, according to the wet scrubbing tower and the waste gas scrubbing method of the present invention, it is possible to reduce the waste liquid of the scrubbing liquid, thereby saving the waste liquid disposal cost.

1 is a cross-sectional view of a wet scrubbing tower to which a humidity control function is added according to an embodiment of the present invention.
Fig. 2 is a flowchart for explaining the waste gas purifying method of the present invention.
FIG. 3 is a photograph of the outlet when purified by a conventional wet cleaning tower.
Fig. 4 is a photograph of an outlet when purified by a washing tower according to the present invention.
5 is a chart showing the hygroscopicity of the water-soluble inorganic salt.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a wet scrubbing tower with a humidity control function according to the present invention and a waste gas purifying method using the same will be described with reference to the accompanying drawings.

The use of the terms "comprises", "having", or "having" in this application is intended to specify the presence of stated features, integers, steps, components, parts, or combinations thereof, But do not preclude the presence or addition of features, numbers, steps, operations, components, parts, or combinations thereof.

Also, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

1 is a cross-sectional view of a wet scrubbing tower to which a humidity control function is added according to an embodiment of the present invention.

As shown in FIG. 1, the wet scrubbing tower with the humidity control function of the present invention includes a waste gas inlet pipe 100 through which waste gas is supplied and a cleaning tower body 200.

The waste gas inlet pipe 100 is provided with a waste gas inlet port 101 which is opened at one side and flows through the waste gas inlet pipe 100 so that the humidity can be controlled and the fine The other side is arranged to communicate with the cleaning tower main body 200 so that the waste gas from which a certain amount of contaminants are removed by contact with the droplet can be moved to the cleaning tower main body 200.

But the present invention is not limited thereto. It is obvious that the cross section of the waste gas inlet pipe 100 is circular, but it can be changed in various ways such as a square, a pentagon, and a hexagon.

In the waste gas inflow pipe 100 of the present invention, the humidity regulator is controlled so that the relative humidity of the introduced waste gas can be maintained within a predetermined range, preferably 40% or more, more preferably 70% or more, and most preferably 100% Respectively.

Particularly, fine particles of water-soluble inorganic salts such as ammonium nitrate, ammonium sulfate, urea, calcium nitrate, potassium nitrate, ammonium phosphate and the like and complex fertilizers containing the same have a high relative humidity as shown in the hygroscopic chart of the water- When the humidity exceeds the above range, there is a property of rapidly absorbing and dissolving the surrounding moisture. Therefore, in the case of the waste gas generated in the manufacturing process for producing these materials, it is very effective to maintain the temperature above the critical relative humidity. However, in the case of the general wet cleaning tower, it's difficult. In the case of ultra fine dust having a particle size of less than 1 탆, even a small amount of dust leaks into the atmosphere and appears to be in the form of white mist and causes serious visible pollution. Therefore, it is necessary to use ammonium nitrate, ammonium sulfate, urea, calcium nitrate, potassium nitrate, In a plant for producing water-soluble inorganic salt and complex fertilizer containing the same, a washing tower equipped with an expensive electrostatic precipitator or a fiber bed filter having a high pressure loss is installed in order to prevent visible pollution, There is a problem.

The humidity controller may include one or more first, second and third injection nozzles 111, 131, 141, at least one first and second humidity measurement sensors H-1, H-2, F-1, F-2, F-3, and F-4, one or more first, second and third temperature measurement sensors T-1 and T- And a control unit 300 for controlling the sensors H, T, and F. FIG.

In the conventional wet scrubbing tower, a cleaning liquid is sprayed to remove various pollutants contained in the waste gas, and the thus sprayed cleaning liquid comes into contact with the waste gas so that various contaminants are dissolved in the cleaning liquid or collected in the liquid droplet and removed from the waste gas stream.

However, in the conventional wet scrubbing tower, a large amount of droplets having a diameter of about 500 to 1000 μm is injected to contact with the waste gas in order to increase the removal efficiency of the contaminants, and thus the efficiency of removing contaminants is not high, In addition, maintenance costs such as power costs due to pump operation are taking a lot of time.

On the other hand, according to the present invention, by controlling the humidity of the waste gas from the inflow pipe (100) through which the waste gas first flows, it is possible not only to improve the removal efficiency of contaminants but also to reduce the power ratio at the time of drop ejection.

The first injection nozzle 111 located inside the waste gas inlet pipe 100 injects the cleaning liquid stored and circulated in the cleaning tower main body 200 to be described later to adjust the humidity of the space portion where the waste gas moves to a predetermined range. That is, the cleaning liquid supplied to the cleaning liquid first circulation line 110 connected to the cleaning tower main body 200 is supplied through the first injection nozzle 111 to a minute droplet, more specifically, a liquid having a diameter of 5 μm to 50 μm Spray the enemy. If the droplet exceeds 50 탆, it is difficult to control the humidity. Therefore, the liquid sprayed from the first spraying nozzle 111 must be used in order to spray the droplet less than 5 탆, The smaller the above range, the better.

A second injection nozzle 131 may be further provided on the first injection nozzle 111 for precise humidity control. The second injection nozzle 131 is connected to the first water supply line 130, unlike the first injection nozzle 111, and controls the humidity by injecting water.

A cleaning liquid containing chemicals such as nitric acid or sulfuric acid is circulated at the bottom of the cleaning tower main body 200 to be described later in order to remove contaminants contained in the waste gas. However, in the process of circulating and spraying the cleaning liquid, a certain amount of water is discharged to the clean gas outlet 201. Therefore, in order to maintain the concentration of the cleaning liquid in a predetermined range, water must be replenished periodically.

The water supplied to the second injection nozzle 131 of the present invention not only helps to control the humidity but also functions to replenish the evaporated water, so that the power ratio required for driving the pump can be reduced.

Here, it is preferable that the second injection nozzle 131 injects a droplet having a diameter of 5 mu m to 50 mu m like the first injection nozzle 111. [

Reference numeral 120 denotes an air supply line. Generally, the injection nozzle has an air flow nozzle for supplying and spraying a first-flow nozzle and a compressed air which are sprayed by a driving force of a high-pressure pump. In the present invention, the air supply line 120 And supplies the compressed air to the cleaning liquid first circulation line 110 and the first water supply line 130 so that a fine droplet is ejected from the first ejection nozzle 111 and the second ejection nose 131 Respectively.

 In addition, a third injection nozzle 141 may be further provided on the second injection nozzle 131 for more precise control of the humidity. Specifically, the third injection nozzle 141 is connected to the steam supply line 140 to adjust the humidity by injecting steam.

The steam is made of fine droplets. When the outside air temperature is low as in the winter season, the steam can act to increase the temperature of the introduced waste gas, so that it is possible to more easily control the humidity inside the waste gas inlet pipe 100.

A first humidity sensor (H-1) for measuring the humidity of the waste gas flowing into the waste gas inlet pipe (100), and a second humidity sensor 1 and a first flow sensor F-1 for measuring a flow rate are preferably provided on the bottom of the washing tub main body 200. The first flow sensor F- A second humidity sensor (H-2) and a second temperature sensor (T-2) are provided behind the first injection nozzle (111) to measure the humidity and temperature of the waste gas after coming into contact with the cleaning liquid .

The first humidity sensor H-1, the first temperature sensor H-1 and the first flow sensor F-1 measure the humidity, the temperature and the flow rate of the waste gas flowing into the waste gas inlet pipe 100 The second flow sensor F-2 provided in the cleaning liquid first circulation line 110, and the third flow sensor F-1 provided in the first water supply line 130 so that the humidity can be controlled in a predetermined range based on these results, And a fourth flow sensor F-4 provided in the sensor F-3 and the steam supply line 140. The flow rate sensor F-

The second humidity sensor H-2 and the second temperature sensor T-2 are connected to the first humidity sensor H-1, the first temperature sensor T-1 and the first flow sensor F- ) It is to check whether the humidity of the waste gas adjusted according to the measured value is adjusted to the set range.

The humidity sensor, the temperature sensor, and the flow rate sensor are controlled by the controller 300.

Hereinafter, the cleaning tower main body 200 will be described in detail.

A cleaning liquid second circulation line 210, a filler 220, a demister 230, a cleaning liquid supply line 240, and a second water circulation line 210 are connected to the cleaning tower main body 200 connected to the waste gas inlet pipe 100, A supply line 250 is provided.

More specifically, the cleaning liquid circulating line 210 is a line for supplying the cleaning liquid at the bottom of the cleaning tower main body 200 to the filler 220 and the demister 230, Will be described later.

The filler 220 functions to remove contaminants that have not been removed during the passage through the waste gas inlet pipe 100. As described above, the inside of the waste gas inlet pipe 100 is regulated in a predetermined range and the micro droplets are injected to remove various contaminants contained in the introduced waste gas, but some of them are not removed. The filler 220 is for purifying more easily by adsorbing or filtering the contaminants remaining in the waste gas moving in the upward flow. If the contaminants such as the particulate powder, the porous filter and the like can be adsorbed or filtered, the material and the shape are not particularly limited Such a filler corresponds to a structure commonly employed in a wet scrubbing tower, and therefore, a detailed description thereof will be omitted.

The demister 230 located above the filler 220 is for removing moisture contained in the waste gas from which pollutants have been removed. The demister 230 is not particularly limited as long as gas-liquid separation is possible, but may be, for example, a porous filter.

On the other hand, the waste gas in the cleaning tower main body 200 sequentially passes through the filler 220 and the demister 230, and then the cleaned gas is discharged to the upper clean gas discharge port 201. At this time, the pollutants remaining in the waste gas may accumulate in the fillers 220 and the demister 230, and the waste gas may not move well or channeling phenomenon may occur, resulting in a problem that the efficiency of removing contaminants and moisture is lowered .

The cleaning liquid second circulation line 210 for cleaning the contaminants attached to the filler 220 and the demister 230 is connected to the first branch line 211 and the fifth branch line 211, The fourth injection nozzle 212 is disposed on the top of the demister 230 and the fifth injection nozzle 214 is disposed on the upper side of the filler 220. The second branch line 213 includes the injection nozzle 214, And the cleaning liquid is sprayed in a direction opposite to the waste gas flow.

The third temperature sensor T-3 and the third humidity sensor H-3 located in the space under the filler 220 can determine whether the waste gas flowing through the waste gas inlet pipe 100 maintains the humidity in a predetermined range The fourth temperature sensor T-4 and the fourth humidity sensor H-4 on the upper side of the demister 230 monitor the humidity and the temperature of the clean gas discharged from the cleaning tower main body 200 .

Reference numeral 240 denotes a cleaning liquid supply line for supplying chemicals contained in the cleaning liquid, and reference numeral 250 denotes a second water supply line for supplying moisture when the liquid level of the cleaning liquid is lower than a set value due to moisture evaporation. Here, the chemicals in the cleaning liquid may vary depending on pollutants contained in the waste gas, and may be, for example, an acidic substance such as nitric acid or sulfuric acid, or a basic substance such as sodium hydroxide.

Reference numeral 215, which is branched outward from the cleaning liquid circulating line 210, is a drain line for discharging the contaminant to the outside when the contaminant is contained in the cleaning liquid at a predetermined concentration or more.

Hereinafter, a waste gas purifying method according to the present invention will be described with reference to FIG. 2, which is a flowchart for explaining a waste gas purifying method of the present invention.

The method for purifying waste gases according to the present invention comprises the steps of introducing a waste gas into a wet scrubbing column, measuring the humidity of the waste gas, spraying a cleaning liquid so that the humidity of the waste gas falls within a predetermined range, passing the filler, And removing moisture.

Specifically, the waste gas that needs to be purified flows into the waste gas inlet pipe 100. At this time, the humidity sensor, the humidity sensor, the temperature sensor, and the humidity sensor, the temperature sensor, and the flow rate of the waste gas flowing into the flow sensor are measured.

The measured results are transmitted to the controller 300 and the controller 300 controls the first injection nozzle 111 and preferably the first injection nozzle 111 and the second injection nozzle 131, And the humidity is controlled by spraying fine droplets onto the injection nozzle 111, the second injection nozzle 131, and the third injection nozzle 141.

The humidity-regulated waste gas is partially removed in the process of passing through the waste gas inlet pipe 100, and the remaining contaminants are removed while passing through the filler 220 of the cleaning tower main body 200.

In addition, water is removed by passing through the demister 230 so that the final treated gas does not contain moisture, and the clean gas is released to the atmosphere.

Hereinafter, the present invention will be described in more detail with reference to examples. It is to be understood by those skilled in the art that these embodiments are merely illustrative of the present invention and that the scope of the present invention is not construed as being limited by these embodiments.

In order to confirm the effect of the waste gas purifying method according to the present invention, the waste gas was treated with the wet scrubbing tower with the humidity control function shown in Figs. 1 and 2 and the conventional wet scrubbing tower without the humidity control function .

division unit Conventional wet cleaning tower The wet scrubbing tower according to the present invention Waste gas flow rate Nm3 / hr 150,000 150,000 Humidity % (RH) 30 50 Process gas temperature ℃ 51 51 Waste gas fine dust mg / Nm3 70 3 Spray cleaning solution size ㎛ 500 to 1,000 20 to 40 Injection flow rate m3 / hr 350 4 Pump power required kW 45 5

As shown in Table 1, when the humidity was increased by 20% according to the present invention, fine dust contained in the waste gas was reduced to a width greater than 70 mg / Nm 3 of a conventional wet scrubbing tower of 3 mg / Nm 3, Respectively.

In addition, at the flow rate injected by the nozzle, it was 4 m3 / hr which is about 1.1% of 350 m3 / hr of the conventional wet cleaning tower, and it was confirmed that the power can be greatly reduced.

As shown in FIG. 3, which is a picture of the discharge port when purified by the conventional wet scrubbing tower, and FIG. 4, which is a photograph of the discharge port when purified by the scrubbing tower according to the present invention, the waste gas is purified by the apparatus and method according to the present invention Pollutants discharged into the atmosphere can be significantly reduced.

Having thus described a particular portion of the present invention in detail, those skilled in the art will appreciate that these specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby, It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the invention, and that such modifications and variations are intended to fall within the scope of the appended claims.

100: Waste gas inlet pipe
101: Waste gas inlet
110: cleaning liquid first circulation line
111: First injection nozzle
120: air supply line
130: first water supply line
131: Second injection nozzle
140: Steam supply line
141: Third injection nozzle
200: cleaning tower body portion
201: Clean gas outlet
210: cleaning liquid second circulation line
211: first branch line 212: fourth injection nozzle
213: second branch line 214: fifth injection nozzle
215: drain line
220: Filler
230: Demister
231: second circulation line 232: third injection nozzle
233: Fourth injection nozzle
240: cleaning liquid supply line
250: second water supply line
300:
H-1, H-2, H-3 and H-4: First, second, third and fourth humidity sensors
T-1, T-2, T-3 and T-4: first, second, third and fourth temperature sensors
The first, second, third, fourth, fifth and sixth flow sensors F-1, F-2, F-3, F-4, F-
pH: pH sensor

Claims (12)

A cleaning tower main body 200 having a predetermined size and shape; And
And a waste gas inflow pipe (100) for supplying waste gas to the cleaning tower main body (200)
A predetermined space in the waste gas inlet pipe 100 is provided with a humidity controller for controlling the humidity of the waste gas flowing therein,
The humidity control unit includes a first injection nozzle 111 for spraying a cleaning liquid, and the first injection nozzle 111 injects droplets having a diameter of 5 mu m to 50 mu m so as to maintain a relative humidity of 40% or more,
A second injection nozzle 131 is further provided on the first injection nozzle 111,
A third injection nozzle 141 is further provided on the second injection nozzle 131. Steam is injected into the third injection nozzle 141,
A first humidity sensor H-1 for measuring the humidity of the waste gas flowing into the waste gas inlet pipe 100, a first temperature sensor T-1 for measuring the temperature, And a first flow rate sensor (F-1) for measuring the flow rate,
A second humidity sensor (H-2) and a second temperature sensor (T-2) are provided behind the first injection nozzle (111) for measuring the humidity and temperature of the waste gas after contact with the cleaning liquid.
A second flow sensor F-2 for measuring the flow rate of the cleaning liquid supplied to the first injection nozzle 111, a third flow sensor F- 2 for measuring the flow rate of water supplied to the second injection nozzle 131, And a fourth flow sensor F-4 for measuring the flow rate of steam supplied to the third injection nozzle 141,
The first and second humidity measurement sensors H-1 and H-2, the first and second temperature measurement sensors T-1 and T-2, the first, second, And a control unit (300) for controlling the flow rate measuring sensors (F-1, F-2, F-3, F-4).
delete delete The method according to claim 1,
The waste gas inlet pipe (100) is provided with a waste gas inlet (101) opened at one side so as to introduce waste gas to be purified, and the other side is bent at a predetermined angle to communicate with the cleaning column body Wet scrubbing tower with regulating function.
delete delete delete delete The method according to claim 1 or 4,
The waste gas is a water-soluble inorganic salt consisting of ammonium nitrate, ammonium sulfate, urea, calcium nitrate, potassium nitrate or ammonium phosphate; Or a complex fertilizer containing the water-soluble inorganic salt; The wet scrubbing tower having the humidity control function added thereto.
Introducing the waste gas into the wet scrubbing tower of claim 1;
Measuring the humidity of the waste gas; And
And spraying the cleaning liquid so that the relative humidity of the waste gas is 40% or more.
delete 11. The method of claim 10,
The waste gas is a water-soluble inorganic salt consisting of ammonium nitrate, ammonium sulfate, urea, calcium nitrate, potassium nitrate or ammonium phosphate; Or a complex fertilizer containing the water-soluble inorganic salt; Wherein the waste gas is a waste gas generated in the process of producing any one or more of the waste gas.

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