JPS62250928A - Wet gas absorbing treatment device and method - Google Patents

Abstract

PURPOSE:To form a water layer with low pressure loss and enhance gas-liquid contact efficiency by forming more than one couple of porous plates installed within an interval of 200mm in a gas absorption column and counter-current contacting treating gas with absorbing liquid. CONSTITUTION:Gas guided in from a gas introduction section 1 contacts with dropping absorbing liquid accumulated between porous plates 7 and 8 installed within an interval of 200mm, then contacts a liquid layer formed between porous plates 7 and 8 and absorbs. Then, gas contacts the dropping liquid and liquid layer of absorbing liquid between porous plates 5 and 6, absorbs, passes through an exhaust duct 13, a gas-liquid separator 14 and a fan F and is exhausted out of a gas outlet 16. Thus, gas-liquid contacts are repeatedly made between porous plates 5 and 6, and also 7 and 8, to enhance gas-liquid contact efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a gas absorption treatment apparatus and treatment method, particularly to a wet gas absorption treatment apparatus and treatment method.

[Conventional technology]

The wet gas absorption method is known as a method for removing specific gas components, and is frequently used as pollution prevention equipment for preventing air pollution such as various harmful gas components and bad odors, and improving the working environment.

These wet gas absorption methods include packed towers, spray towers,
Methods using absorption devices such as bubble towers and perforated plate towers are common.

[Problems to be solved by the present invention]

Although each of the conventional wet gas absorption methods described above is good, there is a problem in that gas-liquid contact is insufficient, resulting in a low gas absorption rate.

As a countermeasure to this problem, a method has been devised in which gas is passed through a thick water layer in order to achieve sufficient gas-liquid contact. However, with this method, the power of the exhaust fan must be extremely high due to the thickening of the water layer, and the equipment costs will also be enormous. Additionally, there is a risk of secondary pollution such as noise.

Harmful gases, bad odors, etc. must be strictly regulated in terms of pollution, but in most cases they are indispensable for industrial processes.

As a result, there is a risk that operations may be restricted.The present invention responds to the industry's strong demand for efficient removal of such harmful gases, bad odors, etc., with low equipment costs and low running costs. It was developed.

[Means to solve the problem]

The purpose of the present invention is to provide an exhaust gas treatment device and method for improving the working environment and preventing atmospheric pollution such as bad odors caused by the above-mentioned harmful gases. 2 perforated plates held in the gas absorption tower
or more, and two perforated plates are used as a pair, and the distance between one perforated plate and the other perforated plate is 200 mm or less.

This allows 200I between one perforated plate and the other perforated plate.
A thin water layer of less than 11 Pa can be easily formed.

The efficiency of gas absorption depends on how efficiently the water layer and gas can be brought into contact.

Increasing the thickness of the water layer allows for sufficient gas-liquid contact and improves the gas absorption rate, but as the thickness of the water layer increases, the power of the suction fan must also be increased.

If the power of the fan is increased, both the motor and the fan will become larger and the gas absorption tower will become more expensive.

The present invention solves this problem by forming a thin water layer in the middle of a pair of two perforated plates and passing gas through this water layer.

Since the water layer is formed in the intermediate layer between the perforated plates, the absorption liquid flowing in from the upper perforated plate and the absorbing liquid flowing out from the lower perforated plate are violently diffused, creating a turbulent flow, and promoting gas-liquid contact.

It goes without saying that the water layer is multilayered, but the more opportunities there are for gas-liquid contact, the higher the gas absorption rate.

The reason why the distance between the pair of perforated plates is set to 200 mm or less is based on economic considerations, and if the distance exceeds 200 mm, the pressure loss becomes large and it is uneconomical.

On the other hand, the reason why there is no limit on the lower limit of the interval is because the thickness of water layer formation per unit area varies depending on the flow rate and wind speed of the processing gas, and the lower limit is generally not determined.

A gap of approximately 5 mm or more is required to form a water layer and create turbulent flow to promote gas-liquid contact.

Alternatively, the gas can be forcibly fed into the gas absorption tower.
You can use the suction method, but when dealing with high-temperature gases or corrosive gases, it is better to use the suction method, considering the durability of the equipment.

It is also a good idea to install a gas-liquid separator, since the gas and absorption liquid in gas-liquid contact may come into intense contact and liquid droplets may be mixed into the exhaust gas.

[For production]

Next, specific operations will be explained with reference to the attached drawings.

Figure 1 shows an overview of the wet gas absorption treatment apparatus of the present invention.
In the example, gas is introduced into the gas absorption tower 9 from the gas introduction part 1, passed through the gas absorption tower interior 4, is sent to the gas exhaust conduit 13, and proceeds to the exhaust path.

During this time, the gas absorption liquid 3 stored in the absorption liquid storage tank 2 is fed into the gas absorption tower 4 by being sent to the spray mechanism 12 through the circulation pipe 10 and the pump P through the liquid supply pipe 11.

The gas absorption liquid supplied from the spray mechanism 12 is applied to the perforated plate 5.
8, returns to the absorption liquid storage tank 2, and is circulated.

The gas absorption liquid supplied from the spray mechanism 12 is applied to the perforated plate 5.
A liquid layer is formed between the absorption liquid tank 2 and 6 and between the perforated plates 7 and 8, and returns to the absorption liquid storage tank 2 while falling, but this system is in a countercurrent flow to the exhaust path.

The gas introduced from the gas introduction part 1 first passes through the perforated plate 7.
It comes into contact with the falling absorption liquid accumulated between the porous plates 7 and 8, and is absorbed, and then comes into intense contact with the liquid layer formed between the porous plates 7 and 8, and rises while being absorbed.

The gas that has passed through the liquid layer formed between the perforated plates 7 and 8 further comes into contact with the falling absorption liquid that has accumulated between the perforated plates 5 and 6, and absorption occurs. The liquid layer formed in between rises and comes into contact with the gas absorption liquid sprayed from the spray mechanism 12, and is sent to the exhaust conduit 13 while being absorbed.

During this time, the gas-liquid contact mechanism that occurs between the porous plates 5 and 6 is repeated between the porous plates 7 and 8.

The gas sent to the exhaust conduit 13 is then separated from droplets of gas absorption liquid in a gas-liquid separator 14, and the gas passes through the air vent F and is exhausted out of the system from the gas outlet 16.

The gas absorption liquid droplets separated by the gas-liquid separator are collected and returned to the absorption liquid storage tank 2.

The absorption liquid 2 is refreshed quantitatively or periodically to ensure that the efficiency of gas absorption does not deteriorate at all times. [Example] The gas generated from the core soldering of the radiator is introduced into the device shown in Figure 1. The concentration of amine, which is the main component of soldering flux, was measured at the gas outlet.

Amine concentration in base 1 Dongdou gas -・-50ppm Gas wind speed
-・Dynamic pressure of 1.5m/sec fan -20
0mmA q Pore diameter of perforated plate -5mm Porosity of perforated plate -・-33.5% Liquid layer thickness of perforated plate ・・・39mm Two-layer gas absorption liquid
-Water *The measured amine concentration was 0.2ρρ-.

[Comparative example]

The test was conducted under the same conditions as in the example except that the perforated plates of the example were spaced apart and the test was conducted in a state where no liquid layer could be formed between the perforated plates, and the amine concentration was measured.

*The measured amine concentration was 2.01).

〔Effect of the invention〕

When gas is absorbed by the wet gas absorption treatment apparatus according to the present invention as described above, a water layer with extremely low pressure loss can be formed between two perforated plates, so that gas and liquid can be efficiently absorbed without adding any special equipment. It can be used to improve gas absorption equipment.

Therefore, with an inexpensive device, excellent effects can be obtained as a measure for preventing air pollution, preventing bad odors, and improving the working environment.

[Brief explanation of drawings]

FIG. 1 is an example of a sectional view showing an outline of the wet gas absorption device of the present invention, and FIG. 2 is a partially enlarged plan view showing an example of a perforated plate. 1-1---Gas introduction part 2-・Absorption liquid storage tank 3-111 Gas absorption liquid 4-・・・Gas absorption tower interior 5-8・・
-・-Perforated plate 9・-Gas absorption tower 10・−Circulation vibrator 11・−・Liquid sending pipe 12・・・−Spray mechanism 13−
Four exhaust pipes 14... - Gas-liquid separator 15...- Separated liquid return tube 16 - Gas outlet P - Absorbent circulation pump F... - Exhaust fan

Claims (1)

[Claims] 1. Wet gas absorption characterized by forming one or more pairs of two perforated plates held at a distance of 200 mm or less in a gas absorption tower to bring the processing gas and absorption liquid into countercurrent contact. Processing equipment and processing method.