KR800001522B1 - Liquid-gas contactor - Google Patents

Abstract

Mixing device of liquid and gas in absorption process have a counter and parallel flow phase. The gas to be treated enters an upturned U-tube and solvent enters at a higher level Most of the gas rinses to mix with the falling part of the liquid in a counterflow pattern. The gas continuous to flow with the rest of the liquid in parallel with in the second phase around a column. Due to the low gas velocity, the treated gas is separated from the solvent in the downward leg and is drawn off. The ends of the column are immersed in the solvent in the tank to form a lqiuid seal.

Description

Gas-liquid contactor

1 is a perspective view showing an example of a preferred embodiment of the present invention.

2 is a perspective view cut away a portion showing an example of another embodiment of the present invention.

3 to 7 are graphs according to the test results in Examples.

8 is a conceptual diagram showing another embodiment of the present invention.

The present invention relates to a gas-liquid contact device suitable for handling a relatively large amount of gas or liquid.

In more detail, wet flue gas desulfurization using lime lime gypsum or aqueous sodium carbonate or caustic soda solution as an absorption liquid, gas absorption using various absorption liquids, cooling, vaporization, deodorization (脫臭) The contact operation is facilitated by using a gas-liquid contact device suitable for wet vibration damping.

As a conventional gas-liquid contacting device, a banded tower or a packed column is generally used, but either of them is prevented from overflowing the liquid, or because of the problem of countermeasures against reduction of liquid entrainment. Since the common gas velocity could not be increased, the tower diameter had to be increased to handle a large amount of gas or liquid.

Moreover, when using a slurry liquid, there exists a problem, such as scale adhesion in a column. In addition, there are other gas-liquid contact devices such as bubble towers, but it is necessary to study a dispersion plate for dispersing gas in a liquid, and in this case, the gas common speed is remarkably small (for example, 10 cm / sec or less) It is not suitable for the treatment of gas or liquid, and has a large pressure loss.

In order to solve the above problems, there is no structure such as a shelf or packing material in the tower, and the gas-liquid contacting device having a simple structure and the apparatus are used to form a severe gas-liquid recirculation stream, thereby providing effective gas-liquid contact operation. It's about providing it.

That is, according to the present invention, the lower end of the gas rising passage and the lower passage are open to the liquid tank, and the upper portion is in communication with each other. A gas supply port is provided at a relatively lower position, and a liquid supply port is provided at an upper portion thereof, and a gas-liquid contact is carried out by accommodating a substantial amount of liquid by a rapid rising gas flow. A gas-liquid contact device characterized in that a gas outlet is provided and a gas up flow passage and a down flow passage having upper portions communicating with each other by opening with a liquid tank at the bottom thereof, and a lower portion of the gas flow passage with a liquid flow rate and having a relatively lower portion in the liquid tank of the flow passage. A gas supply port is provided at the position, and a liquid supply port is provided at the upper portion thereof, and an apparatus having a gas outlet port contacted with the upper chamber of the liquid tank of the contact liquid tank is used. Accordingly, the gas-liquid contact device is characterized in that the gas common speed Ug is operated at 3 m / sec or more and the liquid mass velocity L is 40,000 to 500,000 kg / m 3 .hr.

Next, the present invention will be described in detail with reference to the drawings.

1 is a perspective view showing an example of a preferred embodiment of the present invention in which gas is absorbed by a liquid. In FIG. 1, 1 is a gas absorption tower, 2 is a gas supply pipe, 3 is a discharge pipe of the contacted gas, 4 is a liquid tank, and 7 is a liquid supply port.

Absorption tower 1 is provided with a gas up flow passage and down flow passage so that they are configured to communicate with each other at the top, and in FIG. 1 are formed by inverted U-shaped pipes. The lower end of the gas ascending passage of the absorption tower 1 opens the liquid velocity, and the lower end of the gas descending passage is opened to the liquid tank 4. A gas supply port 8 is provided on the gas riser side of the absorption tower 1 at a relatively lower position above the liquid tank 4, and a liquid supply port 7 is provided on the upper portion thereof. The liquid tank 4 is partitioned by the partition plate 13 while leaving the flow path between the gas rising channel and the opening of the descending channel, and the liquid tank chamber on the side of the gas rising channel formed by the partition plate 13 and the upper portion of the liquid supply port of the absorption tower 1. The gas reflux tube 5 is provided between and. The gas outlet 9 which has been contacted is provided in the liquid tank chamber on the side of the gas descending flow path which is partitioned by the partition plate 13. The maximum diameter of the absorption tower 1 may be up to about 3 m, at which time gas treatment of approximately 130,000 to 380,000 m 3 / hr may be possible, but preferably, the tower diameter is 2 m or less, and the throughput is up to 170,000 m 3 / hr.

In the gas-liquid contact device having the above-described configuration, the gas to be treated is introduced into the absorption tower 1 from the pipe 2 via the gas supply port 8, but in this case, gas rectification is performed in the vicinity of the gas supply port 8 depending on the flow rate of the gas. Sometimes. On the other hand, the absorbing liquid of the liquid tank 4 is supplied from the liquid supply port 7 into the absorption tower 1 by the pump 10. In this case, the absorption liquid is supplied from one place to the absorption tower 1, but several liquid supply ports may be provided in the vertical direction of the gas riser, and if necessary, a dispersion mechanism may be provided in the supply portion.

The absorbing liquid falling from the liquid supply port 7 contacts the target gas rising from the lower gas supply port 8 to form a countercurrent contact zone between the supply port 7 and the supply port 8. .

)된 가스는 조내에서 기포로 되어 흡수액과 접촉한다. 조 내로 지입되는 가스가 소량이거나 또는 흡수탑 1에서의 가스 흡수가 양호하게 행하여지면 간막이판 13은 불필요하게 된다. 그러나, 그러하지 못할 경우에는, 전술한 조내로 지입되어서 흡수액과 접촉후 접촉되지 않은 가스를 접촉이 끝난 가스 배출구 9에 단락 패스되지 않도록 하기 위하여 간막이판 13을 설치할 필요가 있다.Therefore, the length of the countercurrent contact zone may be determined by appropriately adjusting the height of the supply port 7 in accordance with the flow rate of the gas. For example, when the liquid supply port 7 is installed near the gas supply port 8, the entire interior of the tower is co-flowed. It may also be a contact band. In the lower part of the zone, the absorbing liquid encloses a part of the gas to be treated, forms a co-current contact zone, continues to descend, falls into the liquid tank 4, and is fed into the liquid tank 4.

The gas is bubbled in the tank and comes into contact with the absorbing liquid. If a small amount of gas is introduced into the tank or if the gas absorption in the absorption tower 1 is satisfactorily performed, the partition plate 13 becomes unnecessary. However, if this is not the case, it is necessary to provide a partition plate 13 in order to prevent short-circuiting of the gas which has been introduced into the above-mentioned tank and is not in contact with the absorbent liquid after contact with the gas outlet 9 which has been contacted.

Therefore, the immersion depth of the partition plate 13 may be slightly deeper than the immersion depth on the side by the gas rising flow of the absorption tower 1. The partition plate 13 does not need to partition the entire tank, leaving a flow path for the absorbent liquid.

In this embodiment, the gas which is not absorbed by the absorbing liquid rises to the upper vacancy of the liquid tank 4, passes through the gas reflux tube 5, and returns to the absorption tower 1 from the gas reflux port 6.

However, above the countercurrent contact zone, the gas rising while being in contact with the absorbing liquid accompanies a part or all of the absorbing liquid supplied from the liquid supply port 7, and also merges with the reflux gas described above to raise the inside of the tower to the top of the tower and continue. While descending, a co-current contact zone is formed below the liquid inlet 7.

The gas-liquid mixed phase passing through the zone is separated into the processing gas and the absorbing liquid in the liquid tank 4 so that the processing gas is discharged from the contact gas discharge period 3 and the absorbing liquid is recovered into the tank 4. Moreover, the absorbent liquid is supplied from the supply pipe 11 to the liquid tank 4 and discharged from the discharge pipe 12 to the outside of the tank.

According to the present invention, when a large diameter absorption tower is used, a large amount of gas can be handled, but it is not economical to scale up the embodiment shown in FIG. 1 as it is.

That is, the diameter of the absorption tower 1 becomes large, so that the dimension between the absorption towers of the inverted U-shape becomes large, and therefore, the liquid tank 4 also needs to be large. For example, in the case of a tower diameter of 1 m, the distance between the gas ascending flow path and the gas descending flow path is about 3 m between each center, and the corresponding liquid tank is a circular tank and its inner diameter is about 7 m. However, the original function of the liquid tank does not have to be so large, and there is a problem in economy.

The problem of fabrication of the above-described apparatus can be solved by not tilting the lower portion of the gas rise passage of the absorption tower 1 vertically, but by slightly inclining the lower end thereof to approach the lower end of the gas down passage. In this case, the contact effect does not change even if the gas descending passage is slanted.

In addition, even if the lower end of the gas rise passage of the absorption tower 1 is opened to the liquid velocity via the side surface of the liquid tank 4, the above-described problems can be avoided.

Although the conceptual diagram is shown in FIG. 8, each code | symbol of the same figure is the same as that of FIG. In addition, in this drawing, the lower end of the gas descending passage of the absorption tower 1 is inserted into the inner depth of the upper space of the liquid tank 4 in order to achieve good gas-liquid separation between the contacted gas and the absorbing liquid.

As mentioned above, although the gas ascent flow path has been described with respect to one embodiment, in order to process a large amount of gas or liquid, it is necessary to study the gas-liquid contact efficiently by preventing their drift.

An example thereof will be described using FIG. 2 shown as another embodiment.

In FIG. 2, the code | symbols 1-13 are the same as that of FIG. 1, and description is abbreviate | omitted. In this embodiment, the external shape of the absorption tower 1 is formed in a cylindrical shape, and the partition plate 13 in the liquid tank 4 integrally installed at the lower part of the absorption tower 1 is raised up to the top of the absorption tower 1, so that the gas rising oil and It is characterized by the fact that a downward flow path is formed.

The semi-cylindrical part on the side of the gas rise passage of the absorption tower 1 is immersed in the liquid flow rate of the liquid tank 4 more than the depth by which liquid sealing is possible.

In addition, the gas ascending flow path is also divided by the partition plate 14 separate from the aforementioned partition plate 13 in several zones parallel to the flow of the fluid.

As shown in the figure, the partition plate 14 may be divided on both sides of the gas ascending passage and the cocurrent contact zone below it, or may be divided only by the gas ascending passage.

In addition, depending on the flow rate of the gas to be treated, it may be considered that the top diameter of the absorption tower 1 near the gas supply port 8 is made larger than the upper and lower portions thereof.

Finally, the operating conditions will be described. As apparent from the examples described below, the gas common speed Ug is preferably 3 m / sec or more, preferably 5 to 20 m / sec, and more preferably 5 to 15 m / sec. In addition, the liquid mass rate L is appropriately 40,000 to 500,000 kg / m 2 / hr.

However, in some cases, operations up to about 1,000,000 kg / m 2 / hr are not impossible. When operating under these operating conditions, the liquid can be retained in the apparatus by the kinetic energy of the gas, and the liquid can be refined to make the gas liquid disturbed so that good gas-liquid contact can be achieved.

As described above, according to the present invention, the common speed as described above can be increased, and since there is no structure such as shelves or packing materials in the apparatus, the structure is simple, the pressure loss is small, and the closing by attaching the scale It does not occur In addition, since the whole area of the apparatus of the contact tower and the liquid tank can be utilized as a gas-liquid contact zone, the contact efficiency of gas-liquid increases. In addition, since it is a compact device, the production price of the device becomes cheap.

Example 1

The experiment in which any organic acid contained in the air is absorbed into the aqueous virtual soda solution was made as an apparatus shown in FIG. The tower height of the reverse U-shaped absorption tower is 1.5m and the inner diameter is 50mm. The experimental conditions are shown below.

Supply gas temperature 23-28 ℃

Absorbent temperature 41 ℃

Gas common speed Ug 6,8,10m / sec

Absorption liquid mass rate L 10,000-300,000kg / ㎡.hr

Caustic Soda's Make Up Volume 1.81l / hr (Schedule)

Makeup Caustic Soda Concentration 1.71mol / ℓ (Schedule)

As an analytical method, the inlet gas concentration was measured by ultraviolet absorption method (U.V. 230 mm) by absorbing the free acid in the inlet gas into ethanol.

The organic acid concentration of the outlet gas was determined by gas chromatography (glass column 2m, PEG 20M (10%) + H ₃ PO ₄ (0.5%) Chromosorb WAW-DMCS). Moreover, the absorption rate was calculated from the ratio of organic acid concentrations of the inlet gas and the outlet gas.

Although the results of the experiment are shown in FIG. 3, the water absorption rate is more than 98%, and the absorption rate increases with the increase in the amount of absorbed liquid, but there is no significant difference because the absorption rate is high with respect to the influence of the gas common speed.

Example 2

Absorption experiment of sulfurous acid gas by the calcium carbonate slurry was carried out by the same apparatus as in Example 1.

The experimental conditions are shown below.

Temperature 40 ℃

PH 5.8

Unreacted calcium carbonate concentration in the liquid tank 0.02 to 0.04 mol / l

Total Slurry Concentration 12-16wt%

Calcium Carbonate Excess Rate 1.02-1.04

Inlet sulfur dioxide concentration 500-700ppm

L / G (the ratio of liquid flow rate and gas flow rate in kg / m2) is selected from 3.5, 6.9, and 10.3 as the desulfurization rate (%) on the vertical axis and the common gas velocity Ug (m / sec) on the horizontal axis. The graph of the measured value is shown in FIG.

The graph shows that the desulfurization rate increases with increasing L / G and decreases with increasing gas common speed. If L / G is 3.5 and Ug is low (> 8m / sec), there is a difference in tendency, but this is a phenomenon caused by the contact state of gas-liquid different from other conditions due to the difference in the amount of liquid flow.

The overall results of this experiment can be said that Ug has a high desulfurization rate of 88-97% at high flow rate of 6-10m / sec.

Example 3

The gas-liquid contact operation with water of air was performed as the apparatus shown in FIG. 1, and the total pressure loss in the tower was measured. It is 4.5m high and 300mm inside diameter. Fig. 5 shows a graph of measured values obtained by variously changing the gas column velocity Ug and the liquid mass velocity L. It is clear from the graph that when the gas tower speed becomes more than Ug 5 m / sec, the pressure loss DELTA P is absorbed and the water retention amount increases accordingly, and good gas-liquid contact is made.

Example 4

The experiment of absorption of the sulfurous acid gas by calcium carbonate slurry was performed using the apparatus shown in FIG. The tower height of the absorption tower is 4.5m, the inner diameter is 1000mm, and the partition plate 14 is installed at three places at equal intervals. The experimental conditions are shown below.

Temperature 20-25 ℃

PH 5.8

Unreacted calcium carbonate concentration in liquid tank 0.03-0.5 mol / l

Total Slurry Concentration in Liquid Tank 14-17wt%

Calcium Carbonate Excess Rate 1.03-1.05

The experiment was carried out by selecting two types of inlet sulfur dioxide gas, 500-700ppm and 1400-1500ppm, and L / G for 3.5, 5.2, 6.9 and 10.4.

The graph of the obtained result similarly to Example 2 is shown in FIG.

The graph shows that the desulfurization rate increases with the increase of L / G and increases with the increase of Ua. The difference in tendency between this example and Example 2 is due to the fact that the desulfurization rate is significantly influenced by the contact state of the gas liquid in the absorption tower and the amount of liquid flow.

Example 5

The gas-liquid contact operation of air and water was performed with the same apparatus as in Example 4. Fig. 7 shows a graph of measured values obtained by variously changing the gas column velocity Ug and the liquid mass velocity L. It is apparent from the graph that when the tower speed Ug is 5 m / sec or more, the pressure loss ΔP increases abruptly, and thus the retention of water in the tower increases, resulting in good gas-liquid contact.

Claims (1)

One end is open in the liquid tank and the gas up flow passage and the down flow passage, which communicate with each other at the top, are inverted U-shaped pipes and open in the liquid flow at the bottom of the gas rise flow passage, and the gas is located at a relatively lower position on the liquid tank of the flow passage. The supply port is equipped with a liquid supply port at the upper part thereof, and a gas-liquid contact is carried out by accommodating a substantial amount of liquid by a sudden rising gas flow. Gas-liquid contactor.

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