KR100375604B1 - Net Type Sieve Tray for wet scrubber of flue gas Desulfurization - Google Patents

Abstract

In the present invention, a wet absorption tower sieve tray of a flue gas desulfurization apparatus, a net type sieve tray of a wet absorption tower and a flue gas desulfurization apparatus in which a portion in which gas and liquid are contacted is formed in a net type. ).

The mesh plate for the wet absorption tower of the present invention can increase the contact efficiency of gas and liquid while having a high opening ratio, thereby reducing the size of the device, reducing the power cost of the induction pen, and improving the efficiency of removing harmful gases.

Description

Net Type Sieve Tray for wet scrubber of flue gas Desulfurization}

The present invention relates to a net type sieve tray suitable for a wet scrubber of a flue gas disulfurization device. The product of the present invention can be widely applied to capture SO ₂ , NH ₃ , HCl gas, etc. in the wet absorption tower of the flue gas desulfurization apparatus.

Flue gas desulfurization system absorbs and removes sulfur components such as sulfurous acid gas (SO ₂ ) which is contained in exhaust gas emitted when burning fuel containing sulfur such as coal or bunker C oil in industrial boilers. Say the device.

Sulfur dioxide emissions are strictly regulated under the Environmental Conservation Act.

In the method of removing sulfur dioxide in flue gas, the method of removing sulfur components by dry spraying and contacting powders such as slaked lime or activated carbon, which are neutralizers, with the flue gas during the discharge process of the flue gas is called dry desulfurization method. The method of removing sulfur components by contacting the exhaust gas by spraying the flue gas absorption liquid using an aqueous slurry of limestone as a neutralizing agent is called a wet desulfurization method.

In general, the wet desulfurization apparatus is configured as shown in FIG. 1, injecting sulfur-containing flue gas discharged from the combustion apparatus 1 into the lower part of the absorber through the exhaust gas inlet device 11 and absorbing liquid from the upper part of the absorption tower ( 12) is sprayed and contacted in the absorption tower plate (9) so that the sulfur component reacts with the absorbent liquid, which is converted into an acidic component so as to fall to the bottom of the tower, and the lower absorbent liquid is neutralized with a neutralizing agent and the sulfur component is removed. Allow the bay to discharge from the top of the tower.

The body plate used in the conventional wet absorption tower is mostly a porous plate shape having a circular cell shape as shown in FIG. 2. The perforated plate-shaped sieve makes it easy to manufacture while making contact between the flue gas and the neutralizer slurry relatively easy, and in the case of using the perforated plate-shaped sieve, the upward gas rising through the cell of the perforated plate is the top of the top. As the liquid (neutralizing agent slurry) falling from the crossover gas and liquid on the surface of the tray (Tray) is absorbed instantaneously occurs.

For this reason, a pressure drop (differential pressure) is generated between the inlet and outlet parts by the resistance of the slurry and the slurry injected in the absorption tower. When the differential pressure is generated in this way, an induction pen (ID Fan) for forced induction of exhaust gas is provided. It is necessary. Low differential pressure means that the upward gas is in contact with the liquid with less resistance. In general, in the case of a perforated plate-shaped plate, a differential pressure of about 80 to 100 mmH ₂ O is generated, and enormous power consumption is required to operate the induction pen corresponding thereto.

Increasing the opening ratio (the ratio between the area of the space formed by the holes in the plate and the area of the plate) reduces the differential pressure, but the gas and liquid contact efficiency is lowered, resulting in a lower desulfurization efficiency.

In addition, a packed tower type absorption tower using a filling material such as a Rasch ring may be used. In this case, a problem of closing the absorber due to sludge is high. When the absorption tower is closed, there is a problem in that the entire filling is replaced, and the flowing gas is biased toward the lower pressure, so that fillings such as the Rashihi ring are irregularly arranged, making it difficult to maintain a desired removal efficiency.

Reticulum is a phenomenon in which gas and liquid come into contact with each other and cause aggression when passing through a dense net. That is, when it is blocked by a net or a sieve where the liquid is sprayed, the droplets of the liquid become fine at the rear end due to the resistance, which causes an agricultural phenomenon. This is called a fogging phenomenon.

The inventors of the present invention provide the wet absorbing tower body plate of the flue gas desulfurization device in the form of a mesh made of a wire, thereby increasing the pore size and easily adjusting the size of the cell to facilitate the contact of gas and liquid on the surface of the plate body. At the bottom of the body plate, the fogging phenomenon occurs, so that it is possible to smoothly absorb the fine droplets and reduce the differential pressure, thereby completing the present invention.

SUMMARY OF THE INVENTION An object of the present invention is to provide a wet absorption tower sieve plate that is easier to manufacture and repair than a conventional porous plate-type sieve plate and capable of absorbing waste gas with high efficiency while generating a differential pressure during a gas-liquid contact process.

1 is a schematic view showing a general wet absorption tower.

Figure 2 is a perspective view showing a conventional plate for wet absorption tower of the porous plate shape.

Figure 3 shows the form of the present invention plate,

(a) is the top view of the laminated plate which overlapped two nets,

(b) is an enlarged longitudinal sectional view of (a),

(c) is an enlarged longitudinal cross-sectional view of the plate | board laminated | stacked by superimposing five nets.

-Explanation of symbols for the main parts of the drawing-

1: Combustion device 2: Wet cooling unit

3: flue gas 4: process water

5: absorbent chemical storage tank 6: chemical mixing tank

7: Absorption tower 8: Spray nozzle

9: Net Type Sieve Tray 10: Exhaust Gas

11: exhaust gas inlet device 12: circulating absorption liquid

13: chimney 14: cell

The present invention relates to a mesh plate for a wet absorption tower of a flue gas desulfurization apparatus.

According to the present invention, the compactness of the device can be achieved by using a net-type mesh plate 9 formed in a sieve by weaving wires vertically and horizontally in the wet absorption tower 7. It can take up less factory floor, make it easier to build than other plates, and is easy to repair. Since the mesh plate 9 has a high removal efficiency under the same conditions, its size can be reduced than that of a conventional absorption tower, thereby miniaturizing the device. In addition, since the pressure drop in the absorption tower 7 is small, it can be operated at a high space speed, so that a large amount of waste gas can be treated with a small facility, and the power cost of the induction pen can be reduced by low pressure resistance. In addition, in the case of the reticular body, there is no closed surface other than the longitudinal and horizontal cores, so the opening ratio is high, so there is no problem of closing the absorption tower that may occur in the packed tower. In addition, according to the conditions of the exhaust gas can adjust the number of array of the network plate (9) has the advantage that can be easily adjusted to change the removal efficiency and pressure. This invention showed certain performance in the actual process.

Hereinafter, the configuration and effect of the present invention will be described in detail with reference to Examples.

<Example 1>

As shown in FIG. 3, a mesh plate (cell size of 10 mm) 9 is fabricated in a mesh shape using wires made of stainless material, and five of them are staggered and placed in three absorption towers 7. It was installed as a stage and the experiment to remove the SO ₂ component in the boiler flue gas. At this time, the circulating slurry was sprayed using a spray nozzle 8 and the lower tank of the absorption tower 7 was neutralized with Mg (OH) ₂ to maintain a pH range of about 5.9 to 6.1. In this operation, the present invention was able to obtain the best removal efficiency (95 ~ 99%) at a low differential pressure and an appropriate pH. In addition, under the same conditions, the experiment was performed with a general circular plate having a hole diameter of 10 mm and an opening ratio of 40% to compare the performance of each plate. The concentration of MgSO _{4 in} the absorbent was 5% by weight.

Detailed operating conditions are shown in Table 1 below.

division Slurry circulation flow rate (M ³ / Hr) Exhaust Gas Flow Rate (M ³ / Hr) Differential pressure (mmH ₂ O) Input SO ₂ Concentration (ppm) Emission SO ₂ Concentration (ppm) SO ₂ removal efficiency (%) Invention 59-61 6,000-11,000 20-60 1200 10-85 93-99 Perforated plate 59-61 6,000-11,000 40-105 1200 65-220 82-95

The measurement of SO ₂ measures the inlet concentration at the inlet portion before entering the absorption tower (7), and the outlet SO ₂ through the absorption tower (7) is about 3m below the end of the stack (13). It was measured by real-time SO ₂ , O ₂ , CO ₂ analyzer (Ultramat 23, Zimens, Germany).

<Example 2>

The size of the reticular plate cell was 5 mm and 20 mm, respectively, and the experiment was performed in the same manner as in <Example 1>. Experimental results showed that the cell plate 5 with a cell size of 5 mm showed similar differential pressure and removal efficiency as the conventional porous plate. Chepan (9) of the cell size is 20mm differential pressure were significantly reduced SO _X removal efficiency was good SO _X removal efficiency than the existing trial chepan.

The experimental results are shown in Table 2 below.

division Slurry circulation flow rate (M ³ / Hr) Exhaust Gas Flow Rate (M ³ / Hr) Differential pressure (mmH ₂ O) Input SO ₂ Concentration (ppm) Emission SO ₂ Concentration (ppm) SO ₂ removal efficiency (%) 5mm plate removal efficiency (%) 59-61 6,000-11,000 50-90 1200 30-70 94-98 20mm plate removal efficiency (%) 59-61 6,000-11,000 15-50 1200 35-180 85-97 ※ Differential pressure changed according to boiler operation rate.

In the present invention, the size of one side of the reticulum cells is 5 ~ 20mm and it was confirmed that the plate formed by overlapping the network in 2 ~ 5 layers can exhibit an excellent effect.

Wet absorption tower and flue gas desulfurization apparatus body plate of the present invention can increase the contact efficiency of the gas and liquid while having a high opening ratio has the effect of miniaturizing the device, reducing the power cost of the induction pen, improve the absorption efficiency.

Claims (3)

In the wet absorption tower body plate of the flue gas desulfurization apparatus, the wet absorption tower body plate is formed in the form of a net (net type) of the contact portion of the exhaust gas containing SO ₂ and the exhaust gas absorption liquid. The wet plate according to claim 1, wherein the size of the net cell is 5-20 mm. The wet plate according to claim 1, wherein the plate formed in the portion where the flue gas containing SO ₂ and the flue gas absorption liquid is in contact with each other is composed of a network of 2 to 5 layers.