JPS5911322B2 - Gas-liquid contact device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid-phase continuous type gas-liquid contacting device for blowing gas into a liquid, and more specifically, the present invention relates to a liquid-phase continuous type gas-liquid contacting device for blowing gas into a liquid. The present invention relates to a gas-liquid contact device having a gas blowing mechanism capable of absorbing gas.

Conventionally, in gas-liquid contact devices, when the liquid contains a large amount of soluble salts 10 as a solute caused by absorbed gas or fixative, or when solids are suspended, it is difficult to prevent adhesion due to precipitation of solids. Therefore, various measures are being taken.

The most common method is to saturate the gas with a large amount of water to prevent evaporation15 before the process gas undergoes gas-liquid contact in a gas-liquid contact device, or to install a water-wetted wall in the gas injection pipe. There is a method that expects the effect of forming a gas, saturating the gas, and at the same time washing off the deposited deposits by the flow of water through a wetted wall. However, these methods are generally not economical because they do not allow for efficient spraying of a large amount of water, and may lead to bringing in a larger amount of water than necessary into the system, which may not be acceptable in terms of the process. . In addition, as a measure to prevent the precipitation of solids, a method of mechanically removing the precipitated solids has been considered, but although a temporary effect can be expected25, it cannot be considered as a fundamental solution and is of no concern. The reality is that many of them merely complicate the liquid contacting device, and there are very few practical ones. On the other hand, a gas blowing tube 30 that is generally used in a liquid phase continuous type gas-liquid contact device is open at the lower end, or has an open lower end and has various shapes (rectangular, triangular, circular, etc.) on the lower end side wall. ) With a gas blowing pipe having a notch, the gas is blown out from the free opening end determined by the amount of gas to be processed, so troubles such as clogging due to adhering solids are unlikely to occur, but large waves may occur on the surface of the liquid phase 35. In a gas-liquid contact device using such a gas blowing pipe, the range of operating conditions for achieving stable gas-liquid contact action is significantly narrowed, and the gas-liquid contact efficiency is also poor.

The present inventors have focused on the fact that gas blowing pipes with an open bottom end and gas blowing pipes with a free open end with a notch at the bottom end are suitable for preventing blockages due to adhesion of solids, and have solved the problem of large waves. The present invention has been completed by making intensive efforts to suppress the generation and improve the gas-liquid contact efficiency. That is, an object of the present invention is to provide a gas-liquid contact device having a gas blowing mechanism that can prevent solute solids from depositing and adhering to the gas-liquid contact portion of a gas blowing pipe and efficiently absorb gas. In order to achieve the above object, the present invention has the following configuration.

That is, the gas-liquid contact device of the present invention includes a gas-liquid contact tank, a processing gas introduction zone that extends below the liquid surface and opens at the lower end and/or lower end side wall, and a liquid contactor that extends below the liquid surface and opens at the lower end side wall. It consists of a mantle extending below the surface and surrounding the lower end of the processing gas introduction zone, and a side wall of the mantle has a gas bubbling opening in the -E direction from the opening of the processing gas introduction zone. At the same time, the cross-sectional area of the portion surrounded by the processing gas introduction zone side wall and the mantle side wall is 1 to 10 of the area of the opening in the mantle side wall.
It is characterized by being twice as large. The gas-liquid contact device of the present invention extends the processing gas introduction zone from the gas distribution cylinder above the liquid surface below the liquid surface in the gas-liquid contact tank, and has an opening at the lower end and/or lower end side wall. The processing gas guide 3 is provided, and extends downwardly below the liquid surface, surrounding the lower end of the processing gas introduction zone, and has an upper end closed on the side wall of the processing gas introduction zone.
The basic dispersion mechanism is to provide a mantle having an opening above the opening of the tube.

Since the gas-liquid contacting device of the present invention has such a dispersion mechanism with a double structure, it is possible to achieve extremely good gas-liquid contact efficiency 3 by passing the processing gas through this device, and also to reduce the amount of gas passing through the gas-passing portion. The resistance is low, and it can be operated economically with only pressure loss that is controlled by the liquid level position of the entire gas-liquid contact device. Further, according to the gas-liquid contacting device of the present invention, when dispersing the processing gas in a liquid where solid precipitation is likely to occur due to evaporation of the liquid, water may be introduced into the gas side or mechanically applied to the gas-liquid contact portion. Without using external force, droplets and waves are effectively generated on the inner and outer zones of the lower end side wall of the gas introduction zone using only the energy of the gas itself, and both wall surfaces can be constantly cleaned. , it is possible to prevent solid precipitation to the maximum extent possible.

In addition, the generation of large waves on the liquid phase surface is suppressed by making the cross-sectional area of the portion surrounded by the processing gas introduction zone side wall and the mantle side wall 1 to 10 times the area of the opening in the mantle side wall.
The cleaning effect on the inner wall of the mantle can be maintained. The structure and operation of the gas-liquid contact device of the present invention having such functions will be explained in detail below with reference to the drawings.

FIG. 1 is a schematic structural diagram showing a specific example of the apparatus of the present invention, and FIG. 2 is a longitudinal sectional view thereof.

The processing gas is introduced into the processing gas introduction zone 1, and passes through the lower end side wall opening 2 of the processing gas introduction zone 1 located below the liquid level 5 of the entire gas-liquid contact device and the opening 4 of the outer mantle 3 into the liquid phase. It is dispersed in the form of fine bubbles. Eventually, it rises in the liquid phase due to buoyancy and is guided out of the system. The opening 4 of the mantle 3 is located above the lower end side wall opening 2 of the processing gas introduction zone 1 (at least the upper end of the opening 4 of the mantle 3 is above the lower end side wall opening 2 of the processing gas introduction zone 1). Therefore, by selecting the area of the opening 4 of the mantle 3 to be an appropriate size commensurate with the amount of processing gas, the liquid level 7 in the area surrounded by the process gas introduction zone 1 and the mantle 3 can be maintained at all times. Since the lower end of the processing gas introduction zone 1 can be made higher than the upper end of the side wall opening 2, the processing gas introduced into the processing gas introduction zone 1 5 violently entrains liquid when passing through the lower end side wall opening 2. The liquid is introduced into the opening 4 of the mantle 3 in a gas-liquid mixed phase state, and the inside of the opening 4 of the mantle 3 is vigorously cleaned so that no solids are deposited or deposited.
Here, the liquid level 7 between the processing gas introduction zone 1 and the jacket part 3 is controlled by the size of the opening 4 of the jacket part 3. That is, the larger the passage resistance becomes, the lower the liquid level 7 is pushed down. Therefore, in the present invention, the opening area of the opening 4 of the mantle 3 is selected so that this passing resistance is sufficiently small. On the other hand, when the gas passes through the opening 2 of the processing gas introduction zone 1, liquid is entrained in the gas and flow within the liquid phase also occurs, and liquid is also generated inside the mantle 3.

However, by selecting the height of the liquid level 7 to be sufficiently small, the amplitude of the waves generated within the mantle 3 is suppressed to a small level, and the operating conditions of the gas-liquid contact device are significantly narrowed as in the case without the mantle 3. Rather, the waves generated here have a cleaning effect on the opening 2 through which the gas in the lower part of the processing gas introduction zone 1 passes, and prevent the growth of solids that deposit and adhere to this opening 2. be able to. Furthermore, in order to have a sufficient cleaning effect on the inner wall of the mantle 3, the distance between the side wall of the processing gas introduction zone 1 and the side wall of the mantle 3 is important, and the cross-sectional area S1 of the part surrounded by both is important. The purpose can be sufficiently achieved by selecting the area S2 to be 1 to 10 times, preferably 2 to 5 times, the area S2 of the opening 4 of the mantle 3. A specific example of the apparatus of the present invention has been described above with reference to FIGS. 1 and 2, but the apparatus of the present invention includes the following embodiments.

That is, FIG. 3 shows a case where the processing gas introduction zone 1 opens only at the lower end and does not open at the side wall, and FIG. When the lower end is closed, FIGS. 5 and 6 are schematic diagrams showing two examples in which the two processing gas introduction zones 1 are integrated with the tank 8 of the gas-liquid contact device. As described above, the apparatus of the present invention can be made into various shapes without departing from the technical scope of the present invention. For example, the shape of the processing gas introduction zone 1 is not limited to the rectangular shape described above, but may be other polygonal shapes, circular shapes, etc. In addition, the shape of the mantle 3 or the shapes of the opening 2 of the processing gas introduction zone 1 and the opening 4 of the mantle 3 can be variously modified. Next, an experimental example of a specific example of the device of the present invention will be explained, and its effects will be clarified. Experimental Example 1 Using the gas-liquid contact device of the present invention of the type shown in FIG.
An experiment was conducted in which 450 N of dry air at the same temperature was blown into an aqueous solution (temperature: 55°C) containing % by weight of common salt,
The effect of preventing solute deposition and adhesion was investigated.

The sizes of the main parts of the equipment used are shown below. Cross-sectional area of processing gas introduction zone: 90 mTt x 195 mm Cross-sectional area of mantle: 130 mm x 255 Size and number of cutouts: width 20 m7! L x length? 25011Lm 510 pieces Size and number of mantle openings Diameter 20 (circular), 1
8 pieces S1/S23.66 Vertical distance between the upper end of the processing gas introduction band notch and the upper end of the opening of the mantle 40m77!
In addition, as a comparative experimental example, a gas-liquid gas introduction zone having an opening in the side wall and the area of the opening being equal to the area of the opening in the mantle of the gas-liquid contactor of the present invention was used. Experiments similar to those described above were performed using a contact device (not shown).

The results in both cases are shown in FIG.

FIG. 7 is a graph showing changes in passage resistance (11 water) over the course of operation (number of days), in which A represents an experimental example of the present invention and B represents a comparative experimental example. As is clear from this graph,
In the first comparative experiment, the gas passage resistance showed a tendency to increase rapidly from the middle (about the fourth day), and the operation was discontinued. On the other hand, in the experimental example of the present invention, 240 hours (10 days)
Even after the passage of time, the gas passage resistance did not change. It is thus clear that according to the present invention, precipitation of solutes can be effectively prevented. Experimental Example 2 A container with a diameter of 3 m was filled with water, and a gas-injection experiment was conducted to investigate the generation of waves using the gas-liquid contact device of the present invention, which has a circular processing gas introduction zone and a circular outer shell.

The sizes of the main parts of the equipment used are shown below. Cross-sectional area of processing gas introduction zone: Diameter 100mm (circular) Cross-sectional area of outer mantle: Diameter 170mT! Size and number of L (circular) notches Width 20 mm x length 250 mm 59 pieces Size and number of openings in the mantle Diameter 20 mm (circular), 16 pieces S1/S22.95 Processing gas introduction band notch upper end and mantle Vertical distance from the opening to the soil edge: 40 mm The processing gas introduction zone is arranged in an equilateral triangle with a pitch of 350 mm, and the liquid level when no gas is introduced is set at 1501 t above the upper end of the mantle opening. did.

Also, as a comparative experimental example, the lower end of the processing gas introduction zone has a diameter of 1001D only with a notch structure! Pitch 250m77 L gas introduction pipe to the above 3m diameter container! The same experiment as above was carried out by arranging them in a square arrangement and setting the liquid level when no gas was introduced to be at a position 150 mm above the upper end of the notch.

The results in both cases are shown in FIG.

Figure 8 is a graph showing the change in the maximum liquid level fluctuation width (d) depending on the superficial velocity of 6 gases (M3/hour).V) A in Figure 6
B represents an experimental example of the present invention, and B represents a comparative experimental example. As is clear from this graph, when the gas-liquid contacting device of the present invention is used, stable gas injection with small liquid level fluctuations can be achieved over a wide range of operating conditions (a wide range of gas throughput). can be done. As described above, according to the present invention, it is possible to prevent solute solids from depositing and adhering to the gas-liquid contact portion of the gas blowing pipe, to achieve good gas-liquid contact, and to efficiently absorb the process gas. .

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing one specific example of the device of the present invention, FIG. 2 is a longitudinal sectional view thereof, and FIGS. 3 to 6 are schematic configuration diagrams showing other specific examples of the device of the present invention. FIG. 7 is a graph showing the change in passing resistance depending on the number of days of operation in Experimental Example 1,
FIG. 8 is a graph showing the change in the maximum liquid level fluctuation width due to the gas superficial velocity hemp in Experimental Example 2. DESCRIPTION OF SYMBOLS 1...Processing gas introduction zone, 2...Processing gas introduction zone lower end side wall opening, 3...Outer mantle, 4.
...Opening of the mantle, 5...Liquid level of the entire gas-liquid contact device, 6...Liquid level in the processing gas introduction zone, 7... Liquid level in the area surrounded by the processing gas introduction zone and the mantle, 8...tank.

Claims (1)

[Claims] 1. A gas-liquid contact tank, a processing gas introduction zone extending below the liquid surface and opening at the lower end and/or lower end side wall, and a processing gas introduction zone extending below the liquid surface from the open end of the processing gas introduction zone. It consists of a mantle surrounding the lower end, and a side wall of the mantle has a gas bubbling opening above the opening of the processing gas introduction zone, and a side wall of the processing gas introduction zone and a side wall of the mantle. A gas-liquid contact device characterized in that the cross-sectional area of the portion surrounded by is 1 to 10 times the area of the opening in the side wall of the mantle.