KR100521398B1 - Scrubber system for removing acidic gases - Google Patents

Abstract

The present invention efficiently absorbs various waste gas components containing acidic gas components such as hydrogen chloride, hydrogen fluoride, sulfur oxides, nitrogen oxides, hydrogen sulfide, and sulfurous acid gas generated in the chemical industry, semiconductor or LCD manufacturing industry and many other industrial fields. It is to provide a scrubber system for treating acid gas at the same time without the occurrence of white smoke in the chimney by using a removable high-pressure spray film, an individual eliminator, a packing.

In particular, the packing layer and the mist eliminator in the scrubber is divided into several stages as in the prior art, but separated into two stages, as in the upper layer and the lower layer, so that water is sprayed from the nozzle of the spray tube and then flows in the longitudinal direction. Unlike the conventional case where the lower part of the bed or the mist eliminator is always submerged in water, the contact efficiency decreases, and the water sprayed on the upper layer is discharged to the reservoir through the outlet pipe separately so that the lower layer packing or the mist eliminator There is a feature not to be immersed in.

Description

Scrubber system for removing acidic gases

The present invention efficiently absorbs various waste gas components containing acidic gas components such as hydrogen chloride, hydrogen fluoride, sulfur oxides, nitrogen oxides, hydrogen sulfide, and sulfurous acid gas generated in the chemical industry, semiconductor or LCD manufacturing industry and many other industrial fields. The present invention relates to a scrubber system for treating acid gas using a removable high pressure spray membrane, an individual eliminator, and a packing.

Generally, acidic gas components such as hydrogen chloride, hydrogen fluoride, sulfur oxides, nitrogen oxides, hydrogen sulfide, and sulfurous acid gas generated in the chemical industry, semiconductor or LCD manufacturing industry, and many other industrial fields are mostly contained only a few ppm in the waste gas. In many cases, even a very small amount is not only toxic to the human body but also corrosive to the gas treatment plant and toxic to various catalysts, so it must be removed.

Conventionally, in order to remove the acid gas component from the waste gas, the acid gas is passed through only two or three stages of packing layers and washed by spraying an aqueous solution containing alkali, or removed by an absorption operation involving neutralization of acid and alkali. Absorption operation involving such a gas-liquid contact reaction also includes a packing tower, spray tower, scrubber, cyclone scrubber, wet tower, plate column, bubble tower, bubble stirring tower, etc. Several were used in combination.

When acid gas such as hydrogen chloride or nitric acid is mixed with waste gas, the removal rate of acid gas reaches 70 to 90%, but when such gas is released into the atmosphere, it is added to acid mist or acid fume. By producing white fume, a technique for substantially reducing the content of acidic gas to zero is not required.

3 of the accompanying drawings shows a conventional general scrubber system for washing the gas containing the acidic gas component with an aqueous solution containing alkali and absorbing and removing the acidic gas component contained in the gas. 3, the waste gas containing acidic gas is introduced into the scrubber 40 through the supply conduit 41, and the sprayed water passes through the scrubber 42 through the conduit 42 with an alkali component such as NaOH or NaOCl. 40) is sprayed into the waste gas containing acidic gas, the acidic gas is absorbed into the water by spraying alkaline aqueous solution while passing through the packing layer 43 of two or three stages, and the clean gas after the acidic gas is absorbed and removed The exhaust fan 44 is configured to be discharged to the outside. In addition, the water used for spraying is stored in the same tank as a whole, and is used as recycled water, neutralizing with alkaline solution.

This conventional system uses the same alkaline aqueous solution repeatedly in two or three steps of absorbing the packing gas to treat the waste gas containing the acidic gas component. There is a problem that the acid gas remains, and if the cleaning is performed using a relatively high concentration of alkali aqueous solution, the absorption and removal of acid gas can be performed efficiently, but the alkali carbonate produced by the reaction of the carbon dioxide gas and alkali accompanying the gas reacts. Since salts of sediment precipitate and accumulate in the system, there is a problem of inoperability. As a result, a method of washing a gas containing an acid gas component using a low concentration of an aqueous alkali solution may be tried. Is insufficient to remove the gas and release process gas into the atmosphere. In this case, white smoke is generated, which makes workers in the workplace feel unpleasant smells, and the residence time of the gas must be extended to completely prevent the occurrence of white smoke. There is a disadvantage that the operating cost increases.

In particular, although the packing layer 43 is composed of several stages as shown in FIG. 4, when the water flowing down in the longitudinal direction of the packing layer is large, the lower part of the actual packing layer is always filled with water. Adsorption efficiency is lowered due to a decrease in contact area.

Accordingly, the present invention efficiently absorbs various waste gas components containing acidic gas components such as hydrogen chloride, hydrogen fluoride, sulfur oxides, nitrogen oxides, hydrogen sulfide, and sulfurous acid gas generated in the chemical industry, semiconductor or LCD manufacturing industry and many other industrial fields. And a scrubber system for acidic gas which can remove the visible pollution and suppress the occurrence of white smoke, which causes condensate containing contaminants to fall around the outlet, and minimize pressure loss. There is a purpose.

The acid gas treating scrubber system of the present invention includes a scrubber for treating various waste gases containing an acid gas component by a gas-liquid contact method, a compressed air supply conduit for supplying high pressure compressed air to the scrubber, and an alkaline solution. A first water supply conduit for supplying the fresh fresh water to the scrubber reservoir, a waste gas supply conduit for supplying the waste gas containing acid gas to the scrubber, and first and second pumps for supplying water from the scrubber reservoir to the scrubber by a pump. 2 The water return pipes are connected to each other, but the first water return pipe is joined to the compressed air supply conduit and connected to the scrubber by one conduit. The water from the scrubber reservoir is branched to the scrubber by a pump. In the third water return pipe, the water of the third water return pipe in the weak alkali An alkaline supply conduit for supplying a low temperature alkali component to the scrubber reservoir, cooling means for cooling the water in the third water return pipe, and an exhaust pipe and a scrubber reservoir for discharging the clean gas from the scrubber. Characterized in that the conduit for discharging the water continuously to the outside is connected.

According to the present invention, the scrubber is composed of four stages, but the conduit conduit of the first water return pipe and the high pressure air supply conduit is connected, and a nozzle for spraying water at high pressure toward the waste gas flowing into the scrubber. A first stage having a spray tube equipped with a mist eliminator disposed behind the spray tube; The second water return pipe from the scrubber reservoir is connected to a spray pipe having a nozzle for spraying water at a high pressure in the same direction as the flow of unabsorbed acid gas at the first stage, and in front of the spray pipe A second stage in which a packing layer is disposed; A third stage in which the third water return pipe from the scrubber reservoir is connected to the spray pipe having a nozzle in the form of a branch pipe and a packing layer is disposed in front of the spray pipe as in the second stage; And a fourth stage in which the third water return pipe from the scrubber reservoir is connected to the spray tube having a nozzle in the form of a branch tube, and a mist eliminator is disposed in front of the spray tube as in the case of the third stage. Characterized in that consists of.

In addition, the present invention is the packing layer and the mist eliminator in the scrubber is composed of a structure separated into two stages of the upper layer and the lower layer, the scrubber reservoir has a partition wall so that the water can overflow, the water from the scrubber It is characterized by having an outlet pipe which can be discharged.

When described in more detail based on the accompanying drawings of the present invention as follows.

1 is a configuration diagram of an acid gas treating scrubber system according to the present invention, and FIG. 2 is an enlarged detailed view showing a structure of a packing layer in the scrubber of FIG. 1.

As shown in FIG. 1, a scrubber system for treating an acid gas according to the present invention includes hydrogen chloride, hydrogen fluoride, sulfur oxides, nitrogen oxides, hydrogen sulfide, and sulfurous acid, which occur in the chemical industry, the semiconductor or LCD manufacturing industry, and various other industrial fields. Scrubber 10 for treating various waste gases containing acidic gas components such as gas by gas-liquid contact method, compressed air supply conduit 11 for supplying high pressure compressed air to the scrubber 10, and alkaline solution Fresh water supply conduit 13 for supplying fresh fresh water to the scrubber reservoir 12, waste gas supply conduit 14 for supplying waste gas containing acid gas to the scrubber 10, and the scrubber The first and second water return pipes 16 and 16 'for supplying the water of the reservoir 12 to the scrubber 10 by the pumps 15 and 15' are connected to each other. Itdoe where water once songgwan 16 is connected to a scrubber 10, with a single joining conduit 17 to join with the compressed air supply conduit (11).

On the other hand, in the present invention, the scrubber 10 is composed of four stages (A, B, C, D) as illustrated in detail in Figure 2, but the first stage (A) is the first water return pipe (16) And a conduit (17) of the high pressure air supply conduit (11) and a spray pipe (19) having a nozzle (18) for spraying water at high pressure toward the waste gas flowing into the scrubber (10). It is provided, and the mist eliminator (Mist eliminator 20) is arrange | positioned behind the spray pipe 19. As shown in FIG. Accordingly, fine water droplets are formed by the spray film of water sprayed from the nozzle 18 (to avoid generation of fog caused by reaction with alkali), thereby increasing the surface area of gas-liquid contact, and the water droplets moving along the gas are mist The eliminator 20 collects and removes at a collection efficiency of about 99% or more.

The second stage (B) is a nozzle to which the water return pipe 16 ′ from the scrubber reservoir 12 sprays water at a high pressure in the same direction as the flow of the acid gas that has not been absorbed in the first stage (A) ( 21 is connected to the spray tube 22 provided, and the packing layer 23 is arrange | positioned in front of this spray tube 22. As shown in FIG. Accordingly, when water is continuously sprayed from the nozzle 21 of the spray tube 22 to the packing layer 23 to improve gas-liquid contact, the acid gas unabsorbed in the first stage A is in equilibrium with water. Will be absorbed.

In addition, in the third stage C, as in the case of the second stage B, the third water return pipe 16 '' from the scrubber reservoir 12 is provided with a nozzle 24 in the form of a branch pipe. And a packing layer 26 in front of the spray tube 25. Thus, the water from the nozzle 24 of the spray tube 25 is packed in the same manner as before. Water is continuously absorbed when sprayed because it is neutralized with a weak alkali of pH 8 containing low temperature alkaline components supplied from the alkali supply conduit 27 to the scrubber reservoir 12. The acid gas is neutralized and absorbed and removed.

The water supplied to the third stage C through the third water return pipe 16 "is preferably cooled by using a cooler 28, because the temperature of the acid gas is cooled to Condensation and removal of moisture contained in and to suppress the white smoke generated in the stack, where reference numeral 29 is a cooling water circulation conduit.

On the other hand, the fourth stage (D) is a spray tube in which the third water return pipe (16 ") from the scrubber reservoir (12") is provided with a nozzle (30) in the form of a branch pipe, similarly to the third stage (C) And a mist eliminator 32 in front of the spray tube 31. Thus, the alkali component is neutralized from the nozzle 30 of the spray tube 31 in the same manner as before. Water is sprayed to the mist eliminator 32 when necessary to clean it (not sprayed during normal operation) to prevent the splash of water droplets and simultaneously discharge the 5 μm droplets discharged with the gas up to 99%. Will be removed.

In FIG. 1, reference numeral 33 denotes an exhaust conduit for continuously discharging a part of water from the scrubber reservoir 12 to the outside, and reference numeral 34 denotes an exhaust pipe for discharging clean gas to the atmosphere.

In FIG. 2, reference numeral 35 denotes a partition wall, and reference numeral 36 denotes an outflow pipe for discharging water from the scrubber to the reservoir, and when there is a large amount of water in the front end, the flow overflows through the partition wall in the direction of the arrow.

According to FIG. 2, the packing layers 23 and 26 and the mist eliminators 20 and 32 in the scrubber 10 are not divided into several stages as in the related art, but are divided into two stages as in the upper and lower layers. The upper layer is different from the conventional case, in which the water flowing from the nozzle of the spray tube flows down in the longitudinal direction after the water is sprayed, and the lower part of the packing layer or the mist eliminator is always immersed in the water, thereby decreasing the contact efficiency. The water sprayed on is discharged separately to the reservoir through the outlet pipe so that the packing or mist eliminator of the lower layer is not submerged in the water.

The acid gas treating scrubber system of the present invention includes acid gas components such as hydrogen chloride, hydrogen fluoride, sulfur oxides, nitrogen oxides, hydrogen sulfide and sulfurous acid gas generated in the chemical industry, semiconductor or LCD manufacturing industry, and many other industrial fields. It can effectively absorb and remove the waste gas components, suppress the occurrence of white smoke, which is contaminated with contaminants containing pollutants around the outlet while being visible pollution, and can minimize the pressure loss.

1 is a configuration of the acid gas treatment scrubber system according to the present invention,

FIG. 2 is an enlarged detail view illustrating a structure of a packing layer in the scrubber of FIG. 1.

3 is a block diagram of a conventional acid gas treatment scrubber system,

4 is an enlarged detail view illustrating a structure of a packing layer in the scrubber of FIG. 2.

<Description of the symbols for the main parts of the drawings>

10: scrubber 11: compressed air supply conduit

12: scrubber reservoir 13: fresh water supply conduit

14: waste gas supply conduit 15,15 ': pump

16,16 ': first and second water return pipe 17: conduit conduit

18, 21, 24, 30: nozzles 19, 22, 25, 31: spray pipe

20,32: mist eliminator 23,26: packing layer

27 alkali supply conduit 28 cooler

29: cooling water circulation conduit

33: exhaust conduit 34: exhaust pipe

35: bulkhead 36: outflow pipe

Claims (3)

Scrubber 10 for treating various waste gases containing acidic gas components by gas-liquid contact method, compressed air supply conduit 11 for supplying high pressure compressed air to the scrubber 10, and no alkaline solution Fresh water supply conduit 13 for supplying pure fresh water to the scrubber storage tank 12, waste gas supply conduit 14 for supplying waste gas containing acidic gas to the scrubber 10 and water in the scrubber storage tank 12 The first and second water return pipes 16 and 16 'for resupply to the scrubber 10 by pumps 15 and 15' are respectively connected, but the water return pipe 16 is a compressed air supply conduit ( 11) is joined to the scrubber 10 by one conduit 17 and re-supply the water of the scrubber reservoir 12 into the scrubber 10 by means of a pump 15 ". Third water return tube 16 "for water, said third water return tube 16" Alkali feeding pipe 27 for supplying a low temperature alkali component to the scrubber reservoir 12 so as to be neutralized with weak alkali, cooling means 28, 29 for cooling the water of the third water return pipe 16 ". And an exhaust pipe 34 for discharging clean gas from the scrubber 10 and an exhaust conduit 33 for continuously discharging water from the scrubber reservoir 12 to the outside. Scrubber system for processing gas. The conduit (17) of claim 1, wherein the scrubber (10) is composed of four stages (A, B, C, D), but the conduit (17) of the first water return pipe (16) and the high pressure air supply conduit (11). ) Is connected and a spray tube (19) is provided with a nozzle (18) for spraying water at a high pressure toward the waste gas flowing into the scrubber (10), the rear of the spray tube (19) mist elimine A first end A on which the eater 20 is disposed; The second water return pipe 16 ′ from the scrubber reservoir 12 has a nozzle 21 for spraying water at high pressure in the same direction as the flow of unabsorbed acid gas in the first stage A. A second end (B) connected to the spray tube (22) and having a packing layer (23) disposed in front of the spray tube (22); As in the case of the second stage B, the third water return pipe 16 "from the scrubber reservoir 12 is connected with the spray pipe 25 equipped with the nozzle 24 in the form of a branch pipe, A third end C in which the packing layer 26 is disposed in front of the attaching tube 25; and As in the case of the third stage C, the third water return pipe 16 "from the scrubber reservoir 12 is connected with the spray pipe 31 equipped with the nozzle 30 in the form of a branch pipe, A scrubber system for treating an acid gas, characterized by comprising a fourth stage (D) in which a mist eliminator (32) is disposed in front of the attaching pipe (31). 3. The scrubber storage tank 12 of claim 2, wherein the packing layers 23 and 26 and the mist eliminators 20 and 32 in the scrubber 10 are divided into two stages of an upper layer and a lower layer. Scrubber system for treating the acid gas, characterized in that it has a partition wall 35 so that the water can be overflowed, and has an outlet pipe 36 through which water can flow out of the scrubber (10).