KR20120047586A - Integrated dust-collecting, de-sox, de-nox, and wasteheat recovery system - Google Patents

Abstract

PURPOSE: An integrated dust collection, desulfurization, denitrification, and waste heat recovery system is provided to efficiently eliminate pollutants based on the high temperature heat of exhaust gas from emitted from a combusting furnace. CONSTITUTION: A filtering module(10) includes a filtering bag and implements dust collection, desulfurization, and denitrification operations with respect to exhaust gas in a combusting furnace. A desulfurization reactor(30) is arranged at the front part of the filtering module and implements a desulfurization operation with respect to sulfur oxides in the exhaust gas. A heat exchanging unit(40) is arranged at the rear part of the filtering module. The desulfurization reactor and the filtering module successively implement desulfurization operations. A desulfurization agent supplier(60) is arranged at the front part of the desulfurization reactor. A reducing agent injector(70) is arranged between the desulfurization reactor and the filtering module.

Description

Integrated dust-collecting, de-SOx, de-NOx, and wasteheat recovery system

The present invention relates to an integrated dust collection, desulfurization, denitrification, and waste heat recovery system, and more particularly, through an integrated filtration module to simultaneously and integrally perform dust collection, desulfurization, and denitrification in exhaust gas discharged from a combustion furnace. It relates to an integrated dust collection, desulfurization, denitrification, and waste heat recovery system that can efficiently use the waste heat of the exhaust gas passed through the integrated filtration module.

Some non-industrial industries operate various combustion facilities, such as power generation boilers and incineration boilers, to secure necessary energy, such as electricity or steam. In addition, an air pollution prevention device is necessarily attached to the rear end of the combustion facility in order to remove air pollutants such as dust, sulfur oxides, and nitrogen oxides generated in the combustion process. However, until now, most industries design their air pollution prevention system with only the unit process in mind, so it is not very effective when considering energy level.

For example, air pollution prevention systems installed in power generation boilers generally have a selective catalytic reduction (SCR) that works effectively in the 300 ° C region, an electrostatic precipitator that handles dust, and flue gas desulfurization that can handle sulfur oxides. The devices are installed in order. The system has a problem in that it is discharged to the outside as it is without recovering the thermal energy of 300 ℃, the denitrification catalyst in the SCR is poisoned by the high concentration of dust generated has a problem of reducing the life of the catalyst.

Korean Patent Laid-Open Publication No. 10-2010-0104926 describes an energy-efficient denitrification and desulfurization reactor using waste heat of exhaust gas. Specifically, the fossil fuels such as coal and oil are combusted. Although a denitrification and desulfurization reactor having high energy efficiency has been disclosed by recovering and utilizing combustion exhaust gas waste heat in a process of removing contained nitrogen oxides and sulfur oxides, the plasma reactor is provided by supplying the recovered waste heat to a plasma reactor. Is a denitrification and desulfurization action by supplying a plasma to the SCR, which is a processing apparatus, and there may be a problem in that the high temperature heat discharged from the combustion furnace is not directly transmitted to the SCR.

Korean Patent Laid-Open Publication No. 10-0304080 relates to a system for purifying exhaust gas using an electron beam accelerator, wherein sulfur dioxide and nitrogen oxide contained in the exhaust gas are converted to sulfuric acid and nitric acid by electron beam treatment, and then neutralized in a neutralization reactor. A desulfurization / denitrification treatment method and apparatus thereof in flue gas for reacting with and generating ammonium sulfate and ammonium nitrate are described. The above document describes an apparatus and method for removing contaminants such as sulfur dioxide and nitrogen oxides from the exhaust gas generated as a whole, whereas the treatment method uses an electron beam rather than a heat method. There is a lack of consideration on how to utilize waste heat.

In the prior art, including the existing patent literature, it is described that dust collection, desulfurization and denitrification can be carried out through an air pollution prevention system for exhaust gas discharged from a combustion furnace, but through one unit module. Not only does the technical description of integrated desulfurization, denitrification, and dust collection methods be published, but the technical configuration of recovering waste heat after denitrification and desulfurization by using the heat of exhaust gas discharged from a combustion furnace is somewhat insufficient. There is a problem.

In order to solve the above problems, the present invention provides an integrated filtration module for simultaneously collecting, desulfurizing, and denitrifying gas in exhaust gas, and disposed at a front end of the integrated filtration module to perform primary desulfurization operations for sulfur oxides. Integrated dust collection, desulfurization, denitrification, to improve the efficiency of removing pollutants by using the high temperature heat of the exhaust gas discharged from the combustion furnace in a state including a desulfurization reactor, and a heat exchanger disposed at the rear end of the integrated filtration module. And a waste heat recovery system.

Integrated dust collection, desulfurization, denitrification, and waste heat recovery system according to the present invention provided to achieve the above object is provided with a filter bag therein, and the dust collection, desulfurization, and denitrification process for the exhaust gas in the combustion furnace A desulfurization reactor disposed at a front end of the integrated filtration module to perform a desulfurization process for sulfur oxides in the exhaust gas, and a heat exchanger disposed at a rear end of the integrated filtration module, wherein the desulfurization reactor and The integrated filtration module is characterized in that the desulfurization process is made sequentially.

It may be desirable to include a desulfurizer feeder disposed in front of the desulfurization reactor and a reducing agent injector disposed between the desulfurization reactor and the integrated filtration module.

The filter bag may preferably provide a denitrification structure therein that performs a denitrification process on nitrogen oxides.

It may be preferable that the desulfurization agent supplied from the desulfurization agent feeder is any one or more of a group consisting of slaked lime, limestone, and zeolite.

It may be preferable that the reducing agent supplied from the reducing agent injector is ammonia.

It may be desirable to further include a compressed air supply for providing compressed air between the filter bag and the denitrification structure.

It may be preferable that the interlock fan is provided at the front end or the rear end of the heat exchanger.

It is preferable that the heat exchanger is a fin tube type or a corrosion resistant tube type.

The filter bag is a hollow cylindrical or bent structure, the denitrification structure is inserted and fixed therein, the denitrification structure is a hollow vertical cylindrical structure that maintains a predetermined distance from the filter bag through the upper and lower ends It may be desirable for the gas to flow in and out.

As described above, the present inventors' integrated dust collection, desulfurization, denitrification, and waste heat recovery system include an integrated filtration module for simultaneously performing dust collection, desulfurization, and denitrification in exhaust gas, and disposed at the front end of the integrated filtration module to provide sulfuric acid. In order to increase the removal efficiency of pollutants by using a high temperature heat from the exhaust gas discharged from the combustion furnace, including a desulfurization reactor for performing a primary desulfurization operation for the cargo, and a heat exchanger disposed at the rear of the integrated filtration module. Can be.

The present invention is capable of efficiently removing the sulfur oxides present in the exhaust gas through the continuous desulfurization operation in the desulfurization reactor and the integrated filter module, and by maintaining a sufficient space velocity through the denitrification structure disposed in the filter bag. The oxide component can be effectively collected.

1 is a block diagram of an integrated dust collection, desulfurization, denitrification, and waste heat recovery system for performing dust collection, desulfurization, and denitrification processes for exhaust gas through a series of continuous processes as an embodiment of the present invention; and
Figure 2 is a perspective view showing the configuration of the unit filtration module constituting the integrated dust collection, desulfurization, denitrification, and waste heat recovery system of the present invention.

The above objects, features and other advantages of the present invention will become more apparent by describing the preferred embodiments of the present invention in detail with reference to the accompanying drawings. Hereinafter, an integrated dust collecting, desulfurization, denitrification, and waste heat recovery system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, the overall configuration of the integrated dust collection, desulfurization, denitrification, and waste heat recovery system 100 according to the present invention will be described with reference to FIG. 1.

The integrated dust collection, desulfurization, denitrification, and waste heat recovery system 100 includes an integrated filtration module 10 and a front end of the integrated filtration module 10 that perform the dust collection, desulfurization, and denitrification process for the exhaust gas in the combustion furnace 1. A desulfurization reactor 30 disposed in the exhaust gas and performing a desulfurization process on the sulfur oxides in the exhaust gas, a heat exchanger 40 disposed at the rear end of the integrated filtration module 10, and a desulfurization feeder disposed in front of the desulfurization reactor 30 ( 60), a reducing agent injector 70 disposed between the desulfurization reactor 30 and the integrated filtration module 10, and an interlock fan 50 disposed between the integrated filtration module 10 and the heat exchanger 40. do.

The integrated filtration module 10 includes an exhaust gas inlet 11 disposed at one side and an exhaust gas outlet 12 disposed at the other side. In addition, the integrated filtration module 10 is provided with a plurality of unit filtration module 20 therein, the unit filtration module 20 can each independently act as a purification module for the exhaust gas, and a plurality of It may be configured as.

The exhaust gas generated in the combustion furnace 1 is discharged about 300 degreeC. The exhaust gas contains dust, nitrogen oxides, sulfur oxides, and the like. In order to effectively remove the air pollutants and recover heat, as shown in FIG. 1, an integrated dust collection, desulfurization, denitrification, and waste heat recovery system including a desulfurization reactor 30, an integrated filtration module 10, and a heat exchanger 40 is provided. Go through (100).

In the present invention, the desulfurization agent of lime, limestone, and zeolite-based desulfurization agent is injected in the desulfurization agent supplyer 60, and the injected desulfurization agent reacts in the desulfurization reactor 30 to convert gaseous sulfur oxide into particulate matter. As an example, the reaction mechanism when using slaked lime as a desulfurization agent is shown in the following chemical reaction formula.

_{Ca (OH) 2 + SO 2} → CaSO 3? 1 / 2H 2 O + 1 / 2H 2 O

CaSO ₃ ? 1 / 2H ₂ O + 1 / 2O ₂ + 3 / 2H ₂ O → CaSO ₄ ? 2H ₂ O

As can be seen in the above formula, it can be seen that hydrated lime (Ca (OH) ₂ ) reacts with sulfur dioxide (SO ₂ ) to produce particulate gypsum (CaSO ₄ ). Particulate gypsum produced in the desulfurization reactor 30 is collected into the integrated filtration module 10 through the exhaust gas inlet 11.

Meanwhile, the reducing agent injected from the reducing agent injector 70 is supplied to the integrated filtration module 10 through the reducing agent supply line 72. The reducing agent may be ammonia (NH ₃ ). Specifically, in the integrated filtration module 10, nitrogen oxides (NO _x ) are reduced by using ammonia (NH ₃ ) as a reducing agent, converted to nitrogen (N ₂ ), and removed.

The exhaust gas at about 230 ° C. in which all the dust, sulfur oxides, and nitrogen oxides are removed from the integrated filtration module 10 is effectively recovered from the heat exchanger 40 installed at the rear end and discharged at about 70 ° C. Thereafter, the exhaust gas whose heat is effectively recovered is discharged to the outside through the stack 2.

The heat exchanger 40 is composed of a fin tube type heat exchange material at the front end to recover the heat as much as possible so as not to cause corrosion by exhaust gas condensation, and at the rear end to withstand corrosion due to condensation of the exhaust gas. It may be desirable to install a heat resistant material of the corrosion resistant tube type. Meanwhile, the fin tube and the corrosion resistant tube type may be applicable to both front and rear ends of the heat exchanger 40, and only one tube type may be selectively applied to each.

Examples of the material applied to the corrosion resistant tube type include resins such as Teflon and silicon, inorganic materials, and composite metal materials. Examples of the inorganic materials include ceramics, enamels, glass, and the like.

The interlock fan 50 may be located at the front end or the rear end of the heat exchanger 40 in consideration of a corrosion problem, and as an embodiment, the ID-FAN may be used.

Hereinafter, the unit filtration module 20 constituting the integrated filtration module 10 will be described with reference to FIG. 2.

The unit filtration module 20 includes a plate-shaped dust collecting plate 21 having a spaced distance for collecting dust, a filter bag 24 disposed between the dust collecting plate 21, a filter bag 24, and a dust collecting plate 21. ) And a denitrification structure 25 inserted into and fixed in the filter bag 24, and a fixing panel 23 fixedly disposed on the dust collecting plate 21 and the top of the filter bag 24. .

On the dust collecting plate 21 and the discharge electrode 22, terminals having different polarities are connected to each other to cause dust collection. That is, most of the contaminants introduced into the unit filtration module 20 are collected in the dust collecting plate 21 by a strong electric action formed between the dust collecting plate 21 and the discharge electrode 22.

In addition, the dust in the exhaust gas and particulate gypsum as a byproduct reacted in the desulfurization reactor 30 are attached to the dust collecting plate 21 or the filter bag 24 by the electrostatic force and the filter dust collecting mechanism in the unit filtration module 20. Removal takes place. In addition, the unreacted sulfur oxide in the desulfurization reactor (30) is characterized in that the reaction with the desulfurization agent collected in the filter bag (24) is further removed.

In one embodiment, the filter bag 24 forms a hollow cylindrical container-type structure, and has a hole formed to allow the lower plate 24a and the denitrification structure 25 to penetrate the upper end. Side plate 24b. On the other hand, as another embodiment of the filter bag 24 may be a structure in which some sections are bent.

The filter bag 24 has a property of adsorbing contaminants and undergoes a second desulfurization treatment while collecting the remaining desulfurization agent in the desulfurization reactor 30. That is, after the desulfurization treatment is primarily performed in the desulfurization reactor 30, the desulfurization treatment may be performed in the filter bag 24 again.

The denitrification structure 25 can be configured in a long cylindrical shape and flow through the upper and lower ends. The denitrification structure 25 has a stable arrangement by placing the upper portion through the upper plate 24b of the filter bag 24. The denitrification structure 25 is fixedly disposed therein and spaced apart from the outer surface of the filter bag 24 by a predetermined distance. The exhaust gas from which the sulfur oxides and the dust are removed from the filter bag 24 and the dust collecting plate 21 passes through the denitrification structure 25, and the nitrogen oxides are injected using ammonia (NH ₃ ) injected from the front of the integrated filter module 10 as a reducing agent. (NO _x ) is reduced and converted to nitrogen (N ₂ ) to be removed.

As an important factor affecting the performance of the integrated filtration module 10 in which desulfurization, dust collection, and denitrification occur simultaneously, pressure loss applied to the system can be considered. Since the pressure loss is closely related to the operating cost, how to optimize it is important. The closest relation with the pressure loss is the increase of the pressure loss due to dust collection, which will be described below.

The filter bag 24 and the denitrification structure 25 for effectively dedusting the dust collected in the filter bag 24 in the unit filtration module 20 having the denitrification structure 25 mounted inside the filter bag 24. The compressed air supplied from the compressed air supplier 80 is applied to perform the dust removal operation (reference numerals 28 and 29). Specifically, after compressed air is introduced into the filter bag 24 from the compressed air supply 80 as shown by reference numeral 28, the filter is filtered through a process of discharging based on the outer surface of the filter bag 29 as shown by reference numeral 29. It acts to desorb contaminants 5 such as dust collected in the bag 29.

The dust detached through the above action is effectively moved to the dust collecting plate 21 by the electric field generated between the discharge electrode 22 and the dust collecting plate 21, and is designed to prevent a sudden increase in pressure loss.

1 and 2, the flow of the fluid in the unit filtration module 20 will be described in more detail as follows. Exhaust gas introduced into the unit filtration module 20 through the desulfurization reactor 30 is introduced into the lower portion of the unit filtration module 20 (see reference numeral 26a), and spaced dust collecting plates within the unit filtration module 20 are separated. Although it moves between the (21), it is finally discharged to the outside through the filter bag 24 and the denitrification structure (25).

Exhaust gas introduced into the inside through the side of the filter bag 24 is designed to be introduced into the lower portion of the denitrification structure 25 and discharged to the upper portion of the denitrification structure 25 to have a sufficient space velocity. The space velocity may be understood as referring to a moving speed required for the nitrogen oxide component of the exhaust gas introduced into the denitrification structure 25 to be reduced to nitrogen by reacting with a reducing agent such as ammonia.

Specifically, the flow of exhaust gas flowing through the lower side of the filter bag 24 as shown at 26b and the exhaust flowing through the upper side of the filter bag 24 as shown at 26c are shown. All of the gas flow flows into the filter bag 24 and simultaneously flows into the buffer space 20a on the lower side of the denitrification structure 25. Here, the exhaust gas gathered in the buffer space 20a undergoes a process in which the moving speed is relatively lowered, and at the same time, the exhaust gas naturally flows upward as the pressure increases due to the concentration of the exhaust gas. By the flow of the exhaust gas as described above, the exhaust gas of the buffer space 20a flows in through the lower end of the denitrification structure 25 and is discharged through the upper end (see reference numeral 27). As described above, the flow of the exhaust gas introduced into the unit filtration module 20 (see reference numeral 26) is introduced omni-directionally through the side of the filter bag 24 so as to concentrate flow down the denitrification structure 25. The process allows for the efficient purification of nitrogen oxides.

As described above, the present inventors' integrated dust collection, desulfurization, denitrification, and waste heat recovery system includes an integrated filtration module for simultaneously performing dust collection, desulfurization, and denitrification in exhaust gas, and a sulfur oxide disposed at the front end of the integrated filtration module. Desulfurization reactor for performing the primary desulfurization operation for, and heat exchanger disposed in the rear end of the integrated filtration module can be used to increase the removal efficiency of pollutants by using the high temperature heat of the exhaust gas discharged from the combustion furnace. .

While preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described specific embodiments. That is, those skilled in the art to which the present invention pertains can make many changes and modifications to the present invention without departing from the spirit and scope of the appended claims, and all such appropriate changes and modifications are possible. Equivalents should be considered to be within the scope of the present invention.

1: combustion furnace
2: stack
10: integrated filtration module
11: exhaust gas inlet
12 exhaust gas outlet
20: unit filtration module
20a: buffer space
21: dust collecting plate
22: discharge electrode
23: fixed panel
24: filter bag
24a: bottom plate
24b: top plate
25: denitrification structure
30: desulfurization reactor
40: heat exchanger
50: interlock fan
60: desulfurization feeder
62: desulfurization supply pipe
70: reducing agent injection device
72: reducing agent supply line
80: compressed air supply

Claims (9)

An integrated filtration module having a filter bag therein and performing dust collection, desulfurization, and denitrification for exhaust gas from a combustion furnace;
A desulfurization reactor disposed at a front end of the integrated filtration module to perform a desulfurization process for sulfur oxides in the exhaust gas; And
A heat exchanger disposed at a rear end of the integrated filtration module;
Including;
The desulfurization reactor and the integrated filtration module are integral dust collection, desulfurization, denitrification, and waste heat recovery system characterized in that the desulfurization process is performed sequentially.
The method of claim 1,
The integrated dust collection, desulfurization, denitrification, and waste heat recovery system,
And a desulfurizer feeder disposed in front of the desulfurization reactor and a reducing agent injector disposed between the desulfurization reactor and the integrated filtration module.
The method according to claim 1 or 2,
And said filter bag provides therein a denitrification structure for carrying out a denitrification process for nitrogen oxides.
The method according to claim 1 or 2,
The desulfurization agent supplied from the desulfurization agent supply unit is any one or more of the group consisting of hydrated lime, limestone, and zeolite.
The method according to claim 1 or 2,
The reducing agent supplied from the reducing agent injector is ammonia, dust collection, desulfurization, denitrification, and waste heat recovery system characterized in that.
The method of claim 3, wherein
The integrated dust collection, desulfurization, denitrification, and waste heat recovery system,
And a compressed air supply for providing compressed air between the filter bag and the denitrification structure.
The method according to claim 1 or 2,
Integrated dust collection, desulfurization, denitrification, and waste heat recovery system, characterized in that the interlocking fan is provided at the front or rear end of the heat exchanger.
The method according to claim 1 or 2,
And said heat exchanger is a fin tube type or a corrosion resistant tube type.
The method of claim 3, wherein
The filter bag is a hollow cylindrical or bent shape structure, the denitrification structure is inserted and fixed therein, the denitrification structure is a hollow vertical cylindrical structure that maintains a predetermined distance from the filter bag through the upper and lower ends Integrated dust collection, desulfurization, denitrification, and waste heat recovery system, characterized in that the gas can flow in and out.

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