KR20010104109A - Air curtain guide vane apparatus and process for prevention of lime accumulation at inside wall of semi-dry reactor - Google Patents

Abstract

The present invention is to prevent the sticking of the wall surface of the lime lime (Lime) sprayed to remove the sulfur oxide in the semi-dry scrubber (11), which is mainly adopted as a desulfurization equipment acidic air pollutant generated from the combustion of power plants, incineration facilities Harmful gases (sulfur oxide, hydrogen chloride, etc.) are sprayed with alkali chemicals to absorb, adsorb and neutralize. At this time, the injection of the alkali chemicals is adopted by the high-pressure injection method using a two-fluid nozzle to spray the particles in a fine state. Fine lime particles adhere to the wall of the semi-dry scrubber (11) according to the spray angle and direction to increase the pressure loss in the semi-dry scrubber (11) and to cause corrosion on the wall of the semi-dry scrubber (11) by the deposition of alkaline chemicals. do. In order to avoid attaching alkaline chemical lime to the wall as much as possible, the processing gas is circulated by the blower 13 in the lower duct of the bag filter, and the processing gas is introduced into the upper part of the semi-dry cleaner 11 so that the treated gas is removed from the semi-dry cleaner 11. Provided is a treatment apparatus and method for preventing the adhesion of lime by employing a guide vane device 14 for forming a swirling air curtain on the wall.

Description

Air curtain guide vane apparatus and process for prevention of lime accumulation at inside wall of semi-dry reactor}

The present invention relates to an air curtain guide vane device employed in a semi-dry scrubber for purifying acidic harmful gas contained in exhaust gas discharged from a power plant and an incineration plant.

In general, the harmful gases emitted from power generation and incineration facilities are dust (DUST), hydrogen chloride (HCl), sulfur oxides (SOx), nitrogen oxides (NOx), various heavy metals and trace amounts of dioxins. These harmful gases must be removed and reduced. Select the method and equipment to remove according to the characteristics of harmful gas components. As a facility for removing acidic harmful gas, acidic harmful gases such as sulfur oxides are removed by dry, semi-dry, and wet cleaners, and semi-dry scrubbers are mainly used. In the semi-dry scrubber, alkali chemicals are prepared in a slurry state to neutralize and remove acidic harmful gas, and high-pressure injection by compressed air is performed through a double-fluid nozzle on the top of the semi-dry scrubber. High pressure sprayed lime is attached to the inner wall of the semi-dry scrubber. The result is that the pressure loss (Δp) of the semi-dry scrubber is increased, and the attached alkylene chemical increases the corrosion of the semi-dry scrubber.

Conventionally, in order to prevent alkali adhesion, it is used as a means of preventing the injection of alkali chemicals on the nozzle wall by adjusting the angle of the nozzle, but this method must be premised on the precise spray amount and spray angle of the nozzle. However, this method is difficult to accurately understand the characteristics of the nozzle, the exact distribution of the spray angle, and the accurate calculation of the moving distance, so that the prevention of lime adhesion by this method is difficult.

The present invention was created to improve the above problems, circulating the exhaust gas to form a swirl flow air curtain (Air curtain) by the air curtain (AIR CURTAIN) guide vane device on the top of the semi-dry scrubber (Lime) slurry ( The purpose is to block the access of the walls of the slurry.

1 is a schematic view showing a process diagram for generating an air curtain (AIR CURTAIN) of the semi-dry cleaner according to the present invention,

Figure 2 is a schematic plan view showing the main portion of the top of the semi-dry scrubber,

Figure 3 is a schematic perspective view showing an air curtain (AIR CURTAIN) guide vane,

Figure 4 is a schematic cross-sectional view showing the operating state of the air curtain (AIR CURTAIN) guide vane device employed in the semi-dry scrubber according to the present invention.

<Description of Symbols for Major Parts of Drawings>

11 ... semi-dry cleaner 12 ... bag filter

13 ... Gas circulation blower 14 ... Air curtain guide vanes

15 ... Air-fluid nozzle 16 ... Exhaust gas inlet

17. Circulating gas inlet

In order to achieve the above object, the air curtain (AIR CURTAIN) guide vane device for preventing the adhesion of lime to the wall of the semi-dry scrubber employed in the acidic noxious gas treatment facility according to the present invention is generated in the power generation facility and the incineration facility. The internal structure of the semi-dry scrubber that handles the exhaust gas and the circulation of the exhaust gas are changed. The internal structure is changed into a guide vane structure in which the circulating exhaust gas can act as an air curtain. It is characterized by consisting of a structure in which a membrane (Air Membrane) is formed.

According to the present invention, the air curtain guide vane is attached to the upper part of the semi-dry scrubber in the same manner as the semi-dry scrubber structure to act as an air chamber, so that the circulating exhaust gas flows through the semi-dry scrubber wall by swirling flow. The air curtain guide vane has a wall structure <135 at the bottom to form a strong film on the air film. It is desirable to have a curved shape.

This feature is characterized in that the flow velocity is increased by the air curtain guide vane, which is a structure in which the bottom gas becomes narrower than the upper part when the doubling gas passes through the air curtain guide vane, thereby forming a strong air film. The air membrane thus formed serves to block the lime sprayed by the two-fluid nozzle on the semi-dry scrubber.

According to the present invention, the exhaust gas is circulated with the gas forming the air curtain, and the exhaust gas includes dust, hydrogen chloride (HCl), sulfur oxides (SOx), nitrogen oxides (NOx), various heavy metals, trace amounts of dioxins, and the like. This can cause problems in the system operation such as corrosion by acid gas and increase of heavy metal concentration during recirculation.In consideration of the flow of exhaust gas, acid bag removal and most dust bag are removed. It is preferable to circulate the exhaust gas in the filter rear duct.

According to the present invention, in order to form a thick air film in the air curtain guide vane of the semi-dry scrubber, it is preferable to employ a circulating blower to inject the circulating exhaust gas into the semi-dry scrubber by press-in blowing (usually 200 to 400 mmAq). .

According to the present invention, a method of directly injecting air into the atmosphere, rather than exhaust gas circulation, may be employed. However, when directly injecting air at room temperature, the cooling effect in the semi-dry scrubber is affected, resulting in a change in material and thermal resin. Accordingly, it is desirable to circulate the exhaust gas (usually 160 ° C.) at the rear end of the bag filter as a way to reduce such fluctuation factors.

The air curtain guide vane device employed in the semi-dry scrubber according to the present invention is a device for preventing the lime sprayed from the semi-dry scrubber from being attached to the wall of the semi-dry scrubber.

As shown in FIG. 1, the air curtain guide vane 14 employed in the semi-dry scrubber is installed at the top of the semi-dry scrubber 11, and when the circulated exhaust gas enters the circulating blower 13 through the circulation blower 13, the air curtain As a structural feature of the guide vane 14, the circulating exhaust gas passes through the air curtain guide vanes, increasing the flow rate, thereby making the air curtain phenomenon stand out, thereby forming a rigid air film.

The injection of slaked lime (Alme), an alkali chemical used to remove the harmful gas of the semi-dry scrubber, prevents the lime from adhering to the wall by the air curtain as well as the mixing efficiency of the exhaust gas and the slaked lime (Lime). This increases.

The temperature of the exhaust gas introduced into the semi-dry scrubber 11 is 200 ° C, and the exhaust gas of the semi-dry scrubber outlet temperature is usually 160 ° C. At this time, in the semi-dry scrubber, harmful gas is removed by reacting with lime. The exhaust gas introduced into the bag filter collects and removes most of the dust in the exhaust gas by the bag filter. Air curtain process is composed by circulating most of harmful gas and dust-free exhaust gas to wind pressure 300mmAq by circulating blower.

As shown in FIG. 2, the upper portion of the semi-dry scrubber 11 described above is sprayed with lime into the liquid nozzle 15, and circulating exhaust gas forms swirl flow through the circulating exhaust gas duct 17. Thus, the gas moves to the lower part of the semi-dry scrubber and exhaust gas is introduced into the semi-dry scrubber from the main duct 16.

As shown in FIG. 3, the air curtain guide vane 14 of the semi-dry scrubber 11 has a '-' shaped structure, and forms an air passage on the top of the semi-dry scrubber 11 to form an upper portion of the semi-dry scrubber 11. Serves as an air chamber. The structure of the end portion of the air curtain guide vane 14 is bent to form a structure to increase the flow rate at the end portion where the circulating exhaust gas passes through the air curtain guide vane 14.

Hereinafter, the operation of the air curtain guide vane device employed in the semi-dry cleaner according to the present invention will be described in detail.

As shown in FIG. 4, the exhaust gas containing sulfur oxides, heavy metals, dusts, and the like is introduced into the inlet duct 16 having a structure capable of forming swirl flow, thereby forming swirl flow in the semi-dry scrubber 11. And passes through the semi-dry cleaner 11 in the A direction. Lime is removed to remove harmful gas through the two-fluid nozzle 15 in the form of a cloud, such as B in the form of particulates, react with the harmful gas to form and remove the reaction product. Exhaust gas circulated in the bag filter outlet duct creates a swirl flow air curtain such as C by means of the lime-resistant anti-curve air curtain guide vane 14 to prevent the wall-shape of the B-shaped lime by physical repulsion. To prevent wall attachment.

Although the present invention has been described in detail through specific embodiments, the present invention is not limited to the above embodiments, and various design modifications may be made by those skilled in the art within the scope of the technical idea of the present invention.

As described above, in the semi-dry scrubber according to the present invention, the air curtain guide vane device for preventing the adhesion of lime is prevented from the corrosion caused by the adhesion of lime by preventing the adhesion of alkaline lime. The first advantage is that it works.

In addition, the second advantage is that the air curtain, which serves to prevent the adhesion of lime, improves the efficiency of removing harmful gases by increasing the reaction efficiency due to an increase in the contact chance between lime and the exhaust gas.

In addition, the wall attachment of lime can increase the frictional loss of the exhaust gas, and accordingly maintenance is required, which incurs additional costs due to the maintenance, which prevents the cost and increases the service life of the semi-dry scrubber. There is a third advantage to this point.

In addition, the fourth advantage is that the human resources can be reduced in terms of management because of its simple structure and easy operation and maintenance.

Claims (4)

An air curtain guide vane device that prevents adhesion of lime that is injected to remove exhaust gas containing harmful substances generated from power generation or incineration facilities in a semi-dry scrubber, and circulates exhaust gas behind the back filter. A method of circulating air above the semi-dry scrubber to create swirl flow air curtain to prevent lime from adhering. The method of claim 1, An air curtain guide vane device installed above a semi-dry scrubber to produce a swirl flow air curtain. The method of claim 1 An air curtain guide vane device in which a swirl flow air curtain is formed on the upper portion, so that lime, exhaust gas and air curtain have a countercurrent contact characteristic. The method of claim 1 An air curtain guide vane device having a structure having a curved shape at the end of a guide vane device to increase a flow velocity when air passes through the air curtain to form a strong air film.