JPH08196852A - Gas-liquid contact and device therefor - Google Patents

Abstract

PURPOSE: To attain high contact efficiency with low pressure loss by hanging down plural ropes each having a lot of articulated parts or the like in a gas- liquid contact space in a vessel and feeding a liquid. CONSTITUTION: In a vessel 1 having a gas inlet 7A and a gas outlet 7B, plural ropes 6 each having a lot of articulated parts or projecting parts are hung down almost at fixed intervals, and fixed at the upper ends thereof and arranged almost in parallel. A liquid feeding means 2 is installed in the upper part of the ropes 6 and a liquid flowing down along the ropes and gas are brought into contact with each other in a gas-liquid contact space 3. The liquid which has flowed down in the bottom part of the vessel 1 and has been accumulated in a lower liquid sump 4 is circulated to the liquid feeding means 2 by a pump 8. Thus, a gas-liquid contacting device in which pressure loss of gas is small, the quantity of liquid in contact with gas is increased, and contact area is enlarged, is obtained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a gas-liquid contact device. The device of the present invention is a device for absorbing a specific component in a gas by a component in a liquid, for example, a gas purification device,
It has a wide range of applications such as gas-liquid reactors.

[0002]

2. Description of the Related Art A gas-liquid contactor such as an absorption device has various devices such as a packed column and a plate column, but in general, it can be said that a large gas flow rate can be processed because the gas velocity that can be passed is limited. In addition, the pressure loss is large. With conventional equipment, when trying to process a large amount of gas that does not have pressure on its own, it is necessary to increase the diameter of the equipment or use a blower, which is a disadvantage in industrial practice. .

The Applicant has previously shown that an inverted U in which both legs are put in an absorbing liquid tank is used as a gas-liquid contacting device which does not use a packing or a tray.
An ascending parallel type device was developed in which an absorption liquid supply port was installed in one leg of a V-shaped gas flow path, and a droplet of absorption liquid was entrained and moved in the gas flow, and absorption was performed between them. .

It is rather preferable that the apparatus has a high gas superficial velocity, and therefore, the gas throughput can be increased, the contact efficiency is high, and scales are not attached in the tower.

However, this ascending parallel type gas-liquid contact is
Since the pressure loss is as high as 300 to 500 mmH ₂ O, a booster or the like must be used when the gas to be treated has no pressure. Therefore, the advent of a device for treating a large amount of gas having almost no pressure by gas-liquid contact has been desired.

Japanese Patent Laid-Open No. 47-10109 proposes that a large number of "multi-strand wires" that are hung down at appropriate intervals are so arranged that the liquid flows down and that the flowing liquid and gas come into contact with each other. ing. This contact method is an excellent method in that the pressure loss of gas when passing between the multi-strand wire materials is small.

However, the amount of the liquid held on the wire and in contact with the gas is small with respect to the volume of the space in which the gas is contacted, and the gas-liquid contact area cannot be increased. When absorbing gas by gas-liquid contact,
Increasing the amount of liquid that exists in the gas-liquid contact space of the equipment and that can come into contact with gas and widening the contact area is important, especially when processing a large volume of gas or when achieving a high absorption rate. Request.

[0008]

SUMMARY OF THE INVENTION The general object of the present invention is to meet the above-mentioned needs by reducing the gas pressure loss.
Another object of the present invention is to provide a gas-liquid contactor in which the amount of liquid in contact with gas is increased and the contact area is expanded.

A particular and practical object of the present invention is to increase the velocity of the flowing gas and to reduce the pressure drop, which is comparable to the known device in terms of absorption efficiency and is too expensive to construct and operate. It is to provide a gas-liquid contact absorption device that does not require.

[0010]

As shown in FIG. 1, a gas-liquid contacting method of the present invention comprises a plurality of cords (6) having a large number of articulated portions or protrusions inside a container (1). , Hang it down at approximately equal intervals, fix at least its upper end, and arrange a plurality of cords almost in parallel. Supply the liquid (9) from the upper part of the cord and let the gas flow through the container, It consists of making gas-liquid contact while flowing down the strip.

The direction of liquid flow and the direction of gas flow are
It may be a parallel flow, a counter flow or a cross flow, and a combination of two or more of these may be adopted.

The gas-liquid contacting device of the present invention for carrying out the above-mentioned gas-liquid contacting method is, as shown in FIG. 1, provided in a container (1) having a gas inlet (7A) and a gas outlet (7B). ,
A plurality of cords (6) having a large number of articulated portions or protrusions are hung at substantially equal intervals, and at least the upper ends thereof are fixed to arrange the plurality of cords substantially parallel to each other, and at the top of the cords. A means (2) for supplying a liquid is provided so that the liquid and gas flowing down along the cord are brought into contact with each other in the gas-liquid contact space (3), and flow down to the bottom of the container to the lower liquid pool (4). It is provided with a pump (8) for circulating a part or all of the collected liquid to the above liquid supply means.

In the example shown in FIG. 1, the means for supplying the liquid to the upper part of the cord is to provide a perforated plate (5) in the upper part of the container and fix the upper end of each cord through the hole of the perforated plate. Although it is the upper liquid pool (2) formed by the above, it may be a spray like a liquid spraying the liquid to the upper part of the cord from the side.

As the cord, a ball-and-drop type chain as shown in FIG. 2 is suitable. As shown in FIG. 3, which is an enlarged cross-sectional view of FIG. 2, this ball-drain type chain has a hollow iron dumbbell with two balls, one of which is a large ball and the other of which is a small ball, and which has a hole at the bottom. The unit of (1) is connected by inserting a small ball of another unit into the hole.

Another mode of the ball-and-drop type chain is formed by connecting triangular units shown in FIG.

Yet another aspect of the cord is a wire having a plurality of laterally extending projections as shown in FIG.
This protrusion may have a shape in which one or several protrusions are formed in the shape of a rod in the radial direction, or may be formed in a shape of a disc.

Providing the protrusion directly on the wire has a problem in what to do with the manufacturing process. As a means for obtaining a cord having the same effect without increasing the cost of the device, it is also possible to use a structure in which a large number of beads or abacus beads are passed through a wire as shown in FIG. In either embodiment, the wire can be made of a material that is highly elastic and can have a helical shape as shown in FIG.

In the device of the present invention,
It is advisable to add a means for swinging or applying a force for vibrating this. Specifically, in the case of the device shown in FIG. 1, means for transmitting vibration may be provided to the perforated plate.

[0019]

The gas-liquid contact absorption, which is a typical application example of the present invention, will be explained. In the above-mentioned ascending parallel flow type gas-liquid contact absorption apparatus, the pressure loss is large because the gas entrains the absorption liquid upward. It consumes energy. In order to solve this, it is necessary to let the gas-liquid flow down in parallel, that is, to drop the liquid by its own weight and to carry the liquid to the gas. Since the holdup is reduced, the absorption efficiency is reduced, and a high tower must be prepared.

According to the invention of Japanese Patent Laid-Open No. 47-10109 mentioned above, if the absorbing liquid is made to flow down the wire,
The falling speed of the liquid becomes slower than natural falling, the liquid holdup in the tower is increased, and the contact efficiency is increased. In addition, the absorbing liquid forms a liquid column around this wire, but when the liquid travels down the wire, its surface is renewed and fresh liquid is always exposed, thus reducing the film resistance. be able to.

When a cord having joints or protrusions is used in accordance with the present invention, since the flow path of the liquid is long and the liquid is agitated due to the unevenness of the surface, the liquid is held. As the up is further increased, the liquid level is renewed more violently, so that the gas-liquid contact effect becomes higher.

A comparison of the operating conditions of the existing gas-liquid contacting device and the device of the present invention is as follows.

Absorber type Gas pressure loss Gas superficial velocity Gas liquid ratio [mm Water column] [m / s] [kg / kg] Packing tower 200 to 2,000 1 to 3 0.05 to 10 Shelf tower 50 to 200 1 Below 0.4 to 8 Ascending parallel flow type 300 to 500 10 to 15 1 to 10 JP-A-47-10109 50 or less 2 to 8 1 to 10 units Emission 50 or less 0.1 to 15 1 to 15 Chemical gas absorption by gas-liquid contact When a salt or the like is produced in the liquid, which is accompanied by a reaction, the product flows down while being dissolved in the liquid.
It may also deposit on the surface of the cord. When a large amount is deposited and becomes scale-like, it is necessary to remove this, and as a means for that, an external force such as rocking or vibration is applied to the cord. When the cord is an articulated body that connects units, the joint part is bent by an external force, and the scale is destroyed and peeled off. In the case of a wire having a protrusion, the wire is bent by an external force, and a similar phenomenon occurs. When a highly elastic material is used as the wire and the wire is formed in a spiral shape, the effect of scale peeling can be expected to be higher because the bending deformation is remarkable when an external force is applied.

[0024]

Example 1 The apparatus shown in FIG. 1 was constructed. Vertical 0.2
It has a gas-liquid contact space of m × width 2.0 m × height 1.0 m,
The upper liquid pool was formed by a perforated plate having holes with a diameter of 3.5 mm uniformly provided at a 14 mm triangular pitch on the upper part. On the other hand, the diameter is 0.
Pass a 5 mm x 1 m long wire with a stainless steel ball with a diameter of 3 mm and a hole at the center, and wire 26 per 1 m of wire length.
The 0 pieces were fixed at substantially equal intervals over the entire length.
The upper end of the ball-drop-shaped chain thus prepared was fixed to each hole of the perforated plate and hung down.

Water was supplied to the upper liquid pool on the perforated plate so as to flow down along the jade-shaped chain. The flow rate is
The average was 1.2 kg / hr per chain.

Off gas of FCC (fluid catalytic cracking) device having the following composition (volume%): CO ₂ : 3.2%, O ₂ : 17.2% CO: 0.6% HCl: 1500 ppm N ₂ : The balance is the above. The gas-liquid contactor was put in from one side surface, and was made to flow at a linear velocity of 0.5 m / sec in the form of a cross flow emerging from the other side surface. Gas pressure is 0.002kg / cm ²
G was 0 kg / cm ² · G at the exit.

For comparison, the gas-liquid contact space has a diameter of 3 mm.
mm stainless steel wire was hung down, water was made to flow under the same conditions, and it was made to contact with FCC off gas. The rate of absorption and removal of HCl in the gas by water was 99% in Examples and 9% in Comparative Examples.
It was 0%.

[0028]

Embodiment 2 By modifying the apparatus of Embodiment 1, as shown in FIG. 8, the upper and lower liquid pools are each divided into two, and a front portion and a rear portion (the front and rear are in the order of contact with gas). ) And water is supplied to the lower liquid pool at the rear of the device, and the water overflows into the lower liquid pool at the front of the device over the partition wall, and the liquid at the lower part is circulated to the upper part at the front and rear parts respectively. Thus, two pumps are provided.

A gas containing Cl ₂ : 100 ppm and the balance being N ₂ was circulated at a linear velocity of 0.5 m / sec, while water was 0.2 kg / average on average for each jade-shaped chain.
Gas-liquid contact was performed by letting it flow down at a flow rate of hr.

The removal rate of Cl _{2 in} the gas with water was 96%. The Cl ₂ removal rate is 90% when the structure of FIG. 1 is used as it is, that is, when the apparatus is not divided into front and rear.
Met.

The present invention is not limited to the gas-liquid system shown in the above-mentioned embodiment. For example, in addition to the purification of gas generated in the synthesis of chlorine compounds, the purification of various gases in chemical plants and refineries, It is useful for purification, and can be applied to the treatment of boiler exhaust gas such as desulfurization and denitration.

[0032]

By using the gas-liquid contactor of the present invention, a high contact efficiency can be achieved with a low gas pressure loss, and by contacting a relatively large amount of gas, which has no pressure, with a liquid, The components therein can be advantageously absorbed.

Even if scales are formed on the cords of the apparatus due to the absorption of gas, they can be easily removed. The structure of the device is simple and the construction cost and operating cost are low.

The apparatus of the present invention can be installed in the middle of a flue of combustion gas such as boiler exhaust gas.
In that case, if the gas flow is orthogonal to the filament, and if necessary, the gas-liquid contact space is divided into a plurality of parts, and the gas passes through them in series. The exhaust gas can be treated under the condition that the cross section of the exhaust gas is almost the same as that of the exhaust gas, without causing an extra gas pressure loss.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view conceptually showing a gas-liquid contactor of the present invention and showing the configuration of the apparatus used in Example 1.

FIG. 2 is a side view showing an example of an avalanche type chain used in the present invention.

FIG. 3 is an enlarged cross-sectional view of the ball-drop-shaped chain of FIG.

FIG. 4 is a vertical cross-sectional view showing another example of the ball and whirlpool chain used in the present invention.

FIG. 5 shows another embodiment of the cord used in the present invention,
The side view which showed one part by the cross section.

FIG. 6 shows another embodiment of the cord used in the present invention,
The side view which showed one part by the cross section.

FIG. 7 shows another embodiment of the cord used in the present invention,
The side view which showed one part by the cross section.

FIG. 8 is a vertical cross-sectional view similar to FIG. 1, showing the configuration of the apparatus used in Example 2 of the present invention.

[Explanation of symbols]

 1 Container 2 Liquid Supply Means (Upper Liquid Reservoir) 3 Gas-Liquid Contact Space 4 Lower Liquid Reservoir 5 Perforated Plate 6 Rope 7A Gas Inlet 7B Gas Outlet 8 Pump 9 Liquid

Continuation of the front page (72) Inventor Hiro Sagara 1-14-1 Minami-Bedakan, Yokohama-shi, Kanagawa JGC Corporation Yokohama Office

Claims (8)

[Claims] 1. A plurality of cords having a large number of articulated portions or projections are hung inside the container at substantially equal intervals, and at least the upper ends thereof are fixed to arrange the plurality of cords substantially in parallel. A gas-liquid contact method comprising supplying a liquid from the upper part of the cord and allowing a gas to flow into the container to make a gas-liquid contact while the liquid flows down the cord. 2. The direction of liquid flow down and the direction of gas flow are
The gas-liquid contacting method according to claim 1, wherein the gas-liquid contacting method is carried out in any one of cocurrent flow, countercurrent flow and crossflow, or a combination of two or more thereof. 3. A plurality of cords having a plurality of articulated portions or protrusions are hung at substantially equal intervals in a container having gas inlets and outlets, and at least the upper ends thereof are fixed. Are arranged substantially parallel to each other, and a means for supplying a liquid to the upper part of the cord is provided so that the liquid flowing down through the cord and the gas are brought into contact with each other. A gas-liquid contact device comprising a pump for circulating all of the liquid to the liquid supply means. 4. A means for supplying a liquid to the upper part of the cord is an upper liquid pool formed by providing a perforated plate in the upper part of the container and fixing the upper end of each cord through the hole of the perforated plate. Item 3. A gas-liquid contact device. 5. The gas-liquid contact device according to claim 3, wherein an accordion-shaped chain is used as the cord. 6. The gas-liquid contact device according to claim 3, wherein a wire having a large number of laterally extending projections is used as the cord. 7. The gas-liquid contactor according to claim 3, wherein the cords are formed by passing a large number of beads or abacus beads through a wire. 8. The gas-liquid contact device according to claim 3, further comprising means for applying a force to swing or vibrate the cord.