KR101697705B1 - Apparatus for recovering waste heat and reducing white plume from exhaust gas - Google Patents

Abstract

According to the present invention, disclosed is an apparatus to recover waste heat from exhaust gas and reduce white plume, capable of reducing latent heat and moisture included in exhaust gas to reduce white smoke, and at the same time, effectively removing a pollutant included in the exhaust gas. The apparatus comprises: an absorption tower making the exhaust gas come in contact with an absorptive salt solution to recover the moisture and the latent heat of the exhaust gas, and absorbing the pollutant included in the exhaust gas; an adsorptive salt solution tank to receive the absorptive salt solution came in contact with the exhaust gas; a first heat exchanger circulating at least a part of the absorptive salt solution in the absorptive salt solution storage tank and a circulation water to heat the circulation water; and a second heat exchanger using steam separated from the part of absorptive salt solution in the absorptive salt solution storage tank to heat again the circulation water heated by the first heat exchanger.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a waste heat recovery apparatus,

Disclosed is an apparatus for recovering waste heat of exhaust gas and a white smoke reducing apparatus. More specifically, it is possible to recover latent heat and moisture contained in the exhaust gas, use the recovered latent heat as a heat source, reduce the amount of white smoke generated when the exhaust gas is discharged to the atmosphere, A waste heat recovery and flue gas reduction apparatus for an exhaust gas capable of effectively removing contaminants is disclosed.

Incinerators, metal melting furnaces, boilers, and wet desulfurization facilities generate exhaust gases containing high concentrations of contaminants. In order to remove contaminants contained in the exhaust gas, an absorption tower, that is, a wet type dust collector is generally used.

The wet type dust collector is a device for removing contaminants in the exhaust gas by spraying water into a high temperature exhaust gas. The exhaust gas discharged from the wet type dust collector is discharged into the atmosphere through a stack do.

The exhaust gas discharged through the stack contains saturated moisture, which causes white smoke when it comes into contact with the cool outside air. Specifically, the exhaust gas discharged through the stack is usually at a temperature of 60 to 200 DEG C. When the exhaust gas comes into contact with the cool outside air outside the stack, the saturated moisture in the exhaust gas condenses and drops as a liquid . Since various pollutants are contained in the exhaust gas, condensed and dropped water contains a large amount of harmful substances to human body.

As a method of reducing the white smoke, there is used a method of reducing the relative humidity of the exhaust gas by mixing the exhaust gas with high temperature air or directly heating the exhaust gas by providing a burner on the stack. However, in the case of the former, the installation cost of the air heating and mixing device is very high, and in the latter case, the maintenance cost due to fuel consumption is high.

In addition, a method for reducing white smoke is disclosed in a number of patent documents including Patent Document 1 (Korean Patent No. 10-1200330) and Patent Document 2 (Korean Patent No. 10-375555). However, these patented technologies not only include complicated equipment (wet type dust collecting device) and the like as described above, but also are not effective in reducing white smoke. Patent Document 3 (Korean Patent No. 10-949853) discloses a technique for reducing white smoke by lowering the temperature of white smoke through a heat exchanger, but there is a limit to removing pollutants contained in white smoke. In addition, conventional technologies have focused on reducing white smoke, which is insufficient to recycle heat contained in white smoke.

On the other hand, the physical characteristics of the humid exhaust gas using the psychometric chart are as follows: tx (t: temperature, x: absolute humidity) which is the coordinates of the dry bulb temperature and absolute humidity In the range of ~ 60 ℃, the absolute humidity curve shows a gentle curve. In the range of 60 ~ 70 ℃, the absolute humidity increases along the steep rising curve. In the temperature range above 70 ℃, Respectively. Therefore, it is necessary to control the temperature and humidity of the exhaust gas discharged from the incinerator or the like to an appropriate level (outlet temperature 60 ° C or less, absolute humidity 40 or less).

One embodiment of the present invention provides an apparatus for recovering waste heat of exhaust gas and reducing the amount of pollutants by recycling the recovered latent heat and reducing white smoke and pollutants.

According to an aspect of the present invention,

An absorption tower for contacting exhaust gas with a hygroscopic salt solution to recover moisture and latent heat in the exhaust gas and to absorb contaminants in the exhaust gas;

A hygroscopic salt solution storage tank into which the hygroscopic salt solution in contact with the exhaust gas flows;

A first heat exchanger for heat-exchanging at least a part of the hygroscopic salt solution in the hygroscopic salt solution storage tank and the circulating water to heat the circulating water; And

And a second heat exchanger for reheating the circulating water heated by the first heat exchanger by using water vapor separated from the hygroscopic salt solution in the hypochromic hygroscopic salt solution reservoir,

Wherein one end of the first heat exchanger is connected to a hygroscopic salt solution supply line and the other end is connected to a circulating water supply line, the hygroscopic salt solution in the hygroscopic salt solution reservoir is supplied to the hygroscopic salt solution supply line,

Wherein the hygroscopic salt solution supply line and the circulation water supply line intersect each other in the first heat exchanger, the heat of the hygroscopic salt solution is transferred to the circulation water, and the heated circulation water is circulated through the first heat exchanger Lt; / RTI >

One end of the second heat exchanger is connected to the circulating water supply line extending from the first heat exchanger and the other end of the second heat exchanger is connected to the steam exhaust end of the phase separator,

The phase separator separates at least a portion of the hygroscopic salt solution in the hygroscopic salt solution reservoir into water vapor and liquid, and the separated water vapor is passed through the water vapor discharge end provided at one side of the phase separator to the second heat exchange And then,

Wherein the circulation water supply line and the steam supply line intersect each other in the second heat exchanger and the circulation water of the circulation water supply line is further heated by steam of the steam supply line. The waste heat recovery of the gas and the white smoke reduction device.

The waste heat recovery and white smoke reduction device of the exhaust gas may further include a hygroscopic salt solution supply nozzle disposed at an upper end of the absorption tower to supply the hygroscopic salt solution.

The waste heat recovery and white smoke reduction device of the exhaust gas may include a rare earth ball layer disposed inside the absorption tower for primary contact with the exhaust gas to adsorb pollutants in the exhaust gas and to decompose organic matters in the pollutants .

The hygroscopic salt solution may include an aqueous solution of hygroscopic salts.

The hygroscopic salts include calcium nitrate (Ca (NO ₃ ) ₂ ), ammonium nitrate (NH ₄ NO ₃ ), ammonium sulfate ((NH ₄ ) ₂ SO ₄ ), barium perchlorate (Ba (ClO ₄ ) ₂ ) (KHCO _3), sodium nitrate (NaNO _3), sodium chlorate (NaClO _3), potassium nitrate (KNO _3), barium nitrate _{(Ba (NO 3) 2)} , sodium perchlorate (NaClO _4), sodium chloride (NaCl), calcium chloride (CaCl ₂ ), potassium formate (CHKO ₂ ), hydrates thereof, or combinations thereof.

The rare earth ball is an aggregate of rare earth balls, and the rare earth ball is a ceramic carrier containing rare earths, and the rare earths may be contained in the ceramic carrier in an amount of 0.1 to 0.5 wt%.

The concentration of the hygroscopic salts in the hygroscopic salt solution may be 40 to 80% by weight.

The waste heat recovery and white smoke reduction device of the exhaust gas is provided at one side of the absorption tower and supplies air of low temperature and high pressure to the inside of the absorption tower with respect to the temperature and pressure of the exhaust gas to induce condensation of the exhaust gas. As shown in FIG.

The hygroscopic salt solution supply line extends to the hygroscopic salt solution supply nozzle through the first heat exchanger, and the hygroscopic salt solution that has been heat-consumed by the first heat exchanger may be supplied to the hygroscopic salt solution supply nozzle.

The waste heat recovery and white smoke reduction device of the exhaust gas may further include a distilled water storage tank into which condensation water of the steam discharged from the second heat exchanger flows.

The waste heat recovery and white smoke reduction apparatus of the exhaust gas is characterized in that at least a part of the hygroscopic salt solution in the hygroscopic salt solution storage tank is brought into contact with another circulation water to heat the separate circulation water and to cool the hygroscopic salt solution And a vortex filter for removing contaminants contained in the cooled hygroscopic salt solution discharged from the third heat exchanger.

The apparatus for recovering waste heat of exhaust gas and reducing the white smoke according to an embodiment of the present invention has the following effects.

(1) A solution containing hygroscopic salts such as calcium nitrate can be brought into contact with the exhaust gas to recover the moisture, latent heat and contaminants of the water vapor in the exhaust gas, and the recovered latent heat can be recycled through heat exchange have.

(2) Even if the water recovered from the exhaust gas is continuously supplied into the hygroscopic salt solution reservoir, a certain amount of water is separately introduced into the distilled water reservoir through the phase separator, so that the concentration of the hygroscopic salt can be maintained constant in the hygroscopic salt solution reservoir So that the latent heat, moisture and pollutant recovery characteristics due to the hygroscopic salts can be maintained at the optimal state.

(3) By optimizing the temperature and humidity of the exhaust gas discharged through the stack, it is possible to suppress the occurrence of white smoke, thereby preventing the contaminants from falling due to condensation of water vapor in the white smoke.

FIG. 1 is a schematic view of an apparatus for recovering waste heat of exhaust gas and a white smoke reducing apparatus according to an embodiment of the present invention. Referring to FIG.
FIG. 2 is an enlarged view of an air ejector and its adjacent portions in waste heat recovery and white smoke reduction apparatuses of the exhaust gas of FIG. 1;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus for recovering waste heat of exhaust gas and reducing white smoke according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic view of an apparatus for recovering waste heat of exhaust gas and a white smoke reducing apparatus according to an embodiment of the present invention. Referring to FIG.

1, an apparatus for recovering waste heat and reducing white smoke of an exhaust gas according to an embodiment of the present invention includes an absorption tower 110, a hygroscopic salt solution storage tank 120, and a plurality of heat exchangers 130, 140 and 150 .

The absorption tower 110 plays a role of recovering the pollutants contained in the exhaust gas and the latent heat of the exhaust gas. A hygroscopic salt solution supply nozzle 112 for spraying a hygroscopic salt solution is disposed at the upper end of the absorption tower 110 (that is, at the outlet side end of the exhaust gas), and a rare-earth ball layer 111 .

The hygroscopic salt solution is a solution containing hygroscopic salts, which absorbs latent heat and moisture of the exhaust gas and adsorbs contaminants contained in the exhaust gas.

The hygroscopic salts are excellent in adsorption characteristics of contaminants, have high solubility in water, and have a large difference in solubility according to temperature, so that when the temperature of the hygroscopic salt solution is lowered, the hygroscopic salts precipitate and are easily recovered. Further, the hygroscopic salts cause an endothermic reaction when they are dissolved in water, thereby having an advantage of excellent latent heat recovery characteristics of the exhaust gas.

The hygroscopic salts include calcium nitrate (Ca (NO ₃ ) ₂ ), ammonium nitrate (NH ₄ NO ₃ ), ammonium sulfate ((NH ₄ ) ₂ SO ₄ ), barium perchlorate (Ba (ClO ₄ ) ₂ ) (KHCO _3), sodium nitrate (NaNO _3), sodium chlorate (NaClO _3), potassium nitrate (KNO _3), barium nitrate _{(Ba (NO 3) 2)} , sodium perchlorate (NaClO _4), sodium chloride (NaCl), calcium chloride (CaCl ₂ ), potassium formate (CHKO ₂ ), hydrates thereof, or combinations thereof. For example, the hygroscopic salts may include calcium nitrate hydrate (Ca (NO ₃ ) ₂ .xH ₂ O, x = 4, 6, 8 or 10).

The concentration of the hygroscopic salts in the hygroscopic salt solution may be 40 to 80% by weight.

If the concentration of the hygroscopic salts is less than 40 wt%, the latent heat and the water absorption rate are lowered. If the concentration exceeds 80 wt%, the hygroscopic salts tend to settle or solidify.

The latent heat and the moisture absorption rate vary depending on the types of the hygroscopic salts, and the concentration of the hygroscopic salts can be selectively controlled in consideration of the latent heat and the water absorption rate.

In the absorption tower 110, the exhaust gas and the hygroscopic salt solution may be contacted for at least 1 second at a weight ratio of 1: 2 to 1:10.

The rare earth ball layer is an aggregate of rare earth balls that adsorbs contaminants in the exhaust gas when the exhaust gas is permeated and generates anions to decompose the organic substances contained in the exhaust gas.

The rare-earth ball may be a ceramic carrier containing rare earth metals.

The rare earths may be selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium, or combinations thereof.

The ceramic carrier may include silica (SiO _2), alumina (Al ₂ O _3), or a combination thereof.

The content of the rare earths may be 0.1 to 0.5 parts by weight based on 100 parts by weight of the ceramic support.

Hereinafter, the operation and effect of the waste heat recovery and white smoke reduction apparatus according to an embodiment of the present invention will be described in detail.

First, exhaust gas is supplied through the lower portion of the absorption tower 110. Thereafter, the exhaust gas contacts the rare earth ball layer 111, and the contaminants in the exhaust gas are primarily removed by contact with the rare earth ball layer 111, and the organic matter in the exhaust gas is decomposed. The exhaust gas passing through the rare earth ball layer 111 is in contact with the hygroscopic salt solution injected from the hygroscopic salt solution injection nozzle 112. The contaminants and latent heat in the exhaust gas are absorbed by the hygroscopic salt solution, Falls into the hygroscopic salt solution storage tank 120 connected to one side of the absorption tower 110. Further, the exhaust gas from which latent heat and contaminants are removed is discharged to the outside through the stack 40. The hygroscopic salt solution spraying nozzle 112 may be configured to spray the hygroscopic salt solution in a vortex shape in order to increase the contact efficiency between the hygroscopic salt solution and the exhaust gas.

2, an air ejector 113 may be disposed at one side of the absorption tower 110 to accelerate the latent heat recovery of the exhaust gas. The air ejector 113 is disposed between the hygroscopic salt solution supply nozzle 112 and the rare earth ball layer 111 or below the rare earth ball layer 111 so that the temperature and pressure of the exhaust gas in the absorber 110 And performs a role of accelerating the condensation of the exhaust gas by injecting low-temperature and high-pressure air into contact with the exhaust gas.

In the hygroscopic salt solution storage tank 120, the hygroscopic salt solution falling down from the absorption tower 110 flows. Since the hygroscopic salt solution flowing from the absorption tower 110 absorbs the latent heat of the exhaust gas, the hygroscopic salt solution in the hygroscopic salt solution storage tank 120 is maintained at a high temperature. Also, since the hygroscopic salt solution flowing from the absorption tower 110 contains contaminants such as dust, the contaminants are naturally precipitated to the lower part of the hygroscopic salt solution storage tank 120 and some float.

The hygroscopic salt solution in the hygroscopic salt solution storage tank 120 is used for heat exchange and then supplied to the absorption tower 110. The heat exchangers 130, 140 and 150 may be disposed for the heat exchange.

One end of the first heat exchanger 130 is connected to the hygroscopic salt solution supply line 10 and the other end is connected to the circulation water supply line 20. The hygroscopic salt solution in the hygroscopic salt solution storage tank 120 is supplied to the hygroscopic salt solution supply line 10 through the pump M and the circulation water of the circulation water supply line 20 is supplied to the heat- . The circulating water supply line 20 extends to a position after the discharge end of the second heat exchanger 140 via the second heat exchanger 140. The hygroscopic salt solution supply line 10 passes through the first heat exchanger 130 And reaches the hygroscopic salt solution supply nozzle 112.

The hygroscopic salt solution supply line 10 and the circulation water supply line 20 are disposed so as to intersect with each other in the first heat exchanger 130 so that the heat of the hygroscopic salt solution flows along the circulation water supply line 20 The heated circulating water is transferred to the circulating water flowing into one side of the first heat exchanger 130 and then flows into the first heat exchanger 130 along the circulating water supply line 20 extending to the other side of the first heat exchanger 130. [ As shown in FIG. On the other hand, the hygroscopic salt solution that has lost heat to the circulating water is transferred to the hygroscopic salt solution supply nozzle 112 along the hygroscopic salt solution supply line 10, and can be reused for the latent heat recovery of the exhaust gas and the adsorption of contaminants.

The second heat exchanger 140 further heats the circulating water primarily heated through the first heat exchanger 130 using the hygroscopic salt solution of the hygroscopic salt solution storage tank 120. One end of the second heat exchanger 140 is connected to a circulating water supply line 20 extending from the first heat exchanger 130 and the other end of the second heat exchanger 140 is connected to a phase separator (170). ≪ / RTI >

The phase separator 170 serves to separate at least a portion of the high-humidity hygroscopic salt solution in the hygroscopic salt solution storage tank 120 into water vapor and liquid. The separated water vapor is discharged into the water vapor discharge And flows into the second heat exchanger (140) through the steam supply line (30). At this time, the phase separator 170 can separate at least a part of the hygroscopic salt solution into water vapor and liquid by heating the hygroscopic salt solution by a heating device (not shown).

The circulation water supply line 20 and the water vapor supply line 30 are disposed in the second heat exchanger 140 so as to intersect with each other. The circulation water supply line 20 and the water vapor supply line 30, which are heated to a predetermined temperature via the first heat exchanger 130, (20) is further heated by the water vapor of the water vapor supply line (30). The circulating water, which is further heated by the steam, may move along the extended circulating water supply line 20 and be used for heating water or the like. The condensed water flows into the distilled water storage tank 180 along the condensed water discharge line 30. The condensed water flows through the condensed water discharge line 30 to the distilled water storage tank 180, The condensed water discharge line (30) extends from the water vapor supply line (30).

As described above, since the hygroscopic salt solution flowing into the hygroscopic salt solution storage tank 120 from the absorption tower 110 adsorbs contaminants, the concentration of contaminants increases in the hygroscopic salt solution storage tank 120 with time . Therefore, the contaminants in the hygroscopic salt solution storage tank 120 are precipitated naturally to form sludge, and the sludge is moved to the sludge storage tank and processed through drawing or the like. The bottom of the hygroscopic salt solution reservoir 120 may have a sloped structure for movement to the sludge reservoir.

A vortex filter 160 may be disposed to remove contaminants floating in the hygroscopic salt solution storage tank 120. The vortex filter 160 forms a vortex in the hygroscopic salt solution flowing into the vortex filter 160 to remove contaminants contained in the hygroscopic salt solution. At this time, if the high-humidity hygroscopic salt solution immediately flows into the vortex filter 160, the vortex filter 160 may be damaged due to the high temperature. To prevent this, the third heat exchanger 150 may be further disposed.

One end of the third heat exchanger 150 is connected to the hygroscopic salt solution supply line 11 which is separate from the hygroscopic salt solution supply line 10 and the other end is connected to the circulation water supply line 20 The circulating water is heated by the hygroscopic salt solution at a high temperature and the hygroscopic salt solution which has lost the heat flows into the vortex filter 160. The vortex filter 160 filters contaminants contained in the introduced hygroscopic salt solution, and the filtered hygroscopic salt solution is directly transferred to the hygroscopic salt solution storage tank 120 or is separated from the hygroscopic salt solution storage tank 120 < / RTI > A filter such as silica may be disposed inside the vortex filter 160 and may be cleaned by backwash.

Hereinafter, the waste heat recovery of the exhaust gas and the operation of the apparatus for reducing the white smoke according to one embodiment of the present invention will be described in detail.

The exhaust gas generated in an incinerator or a power plant is supplied to the absorber 110 before being moved to the stack 40. The exhaust gas supplied into the absorption tower 110 comes into contact with the rare earth ball layer 111 in the absorption tower 110 to primarily remove contaminants and decompose the organic substances in the exhaust gas. The exhaust gas passing through the rare earth ball layer 111 is brought into contact with the hygroscopic salt solution sprayed from the hygroscopic salt solution supply nozzle 112, whereby latent heat and contaminants of the exhaust gas are absorbed by the hygroscopic salt solution. The hygroscopic salt solution absorbing the latent heat and the contaminant drops to the lower part of the absorption tower 110 and moves to the hygroscopic salt solution storage tank 120. At this time, low temperature and high pressure air may be supplied to the inside of the absorption tower 110 to promote the latent heat recovery of the exhaust gas to the temperature and pressure of the exhaust gas, so that the air and the exhaust gas can be brought into contact with each other. Condensation water is generated by contact and drops. By the contact between the exhaust gas and the hygroscopic salt solution, the exhaust gas at 60 to 200 ° C is cooled to a temperature of 60 ° C or less, and the absolute humidity can be controlled to 40% or less.

The hygroscopic salt solution that absorbs the latent heat of the exhaust gas is maintained at a high temperature, and the hygroscopic salt solution of high temperature stored in the hygroscopic salt solution storage tank 120 is used for heat exchange. The hygroscopic salt solution and the circulating water flow into the first heat exchanger 130 through the separate lines 10 and 20 and the circulating water in the first heat exchanger 130 is heated by the high hygroscopic salt solution. The hygroscopic salt solution cooled by the first heat exchanger 130 is supplied to the hygroscopic salt solution supply nozzle 112 of the absorption tower 110 and the circulating water heated by the first heat exchanger 130 is supplied to the second heat exchange And is further heated by moving to the heater 140. In the second heat exchanger 140, water vapor is supplied through a separate supply line 30, and the circulating water primarily heated by the first heat exchanger 130 is further heated by the water vapor. At this time, the water vapor supplied to the second heat exchanger 140 may be formed through phase separation of the hygroscopic salt solution. The circulating water heated by the second heat exchanger 140 is ultimately used as heating water or the like, and the condensed water generated by the cooling of the steam moves to the distilled water storage tank 180.

The concentration of the hygroscopic salt solution in the hygroscopic salt solution is preferably 40 to 80 wt%. Even if water in the exhaust gas is continuously supplied to the hygroscopic salt solution storage tank 120, The concentration of the hygroscopic salt solution in the hygroscopic salt solution storage tank 120 can be kept constant as the amount of the condensed water generated in the hygroscopic salt solution storage tank 120 moves to the distilled water storage tank 180.

Meanwhile, the vortex filter 160 is used to remove contaminants from the hygroscopic salt solution storage tank 120, and the hygroscopic salt solution may flow into the vortex filter 160 to remove contaminants. At this time, in order to lower the temperature of the hygroscopic salt solution introduced into the vortex filter 160, the hygroscopic salt solution may pass through the third heat exchanger 150 before entering the vortex filter 160.

In the waste heat recovery and white smoke reduction apparatus according to an embodiment of the present invention, the amount of heat recovered through the heat exchangers (130, 140, 150) is larger than the case of direct heat exchange of ordinary exhaust gas, Because the latent heat of the exhaust gas is recovered through the hygroscopic salt solution and the hygroscopic salt solution containing the latent heat is used for the heat exchange.

Next, waste heat recovery of the exhaust gas and recovery of waste heat by the white smoke reduction apparatus according to an embodiment of the present invention and characteristics of white smoke generation will be described.

Table 1 shows properties of the exhaust gas generated by the simulator, temperature, pressure, flow rate and concentration of aqueous solution of calcium nitrate. In the following Table 1, the stream represents the serial number of the exhaust gas to be discharged. In Table 1, stream 1 contains 13.2 wt% of steam and 3.3 wt% of stream 2.

The result of recovering the waste heat by using the conventional heat exchanger for the stream 1 was 175,200 kcal / hr, and the white smoke and the water phenomenon were observed in the stack. On the other hand, when the stream 1 was treated through waste heat recovery and white smoke reduction apparatus according to an embodiment of the present invention, a heat amount of 714,130 kcal / hr was recovered, and no white smoke and watery phenomenon were observed in the stack. As a result, it was confirmed that the waste heat recovery effect was about four times or more as compared with the conventional technology.

Stream No. Appearance Temperature (℃) Pressure (kg / cm ² ) Flow rate (kg / hr) Concentration (% by weight) ① weather 114 - 12,373 - ② weather 55 - 11,291 - ③ Liquid phase 77 - 62,800 64 ④ Liquid phase 130 - 14,100 70 ⑤ Liquid phase 86 - 76,900 65 ⑥ Liquid phase 86 - 61,700 65 ⑦ Liquid phase 53 - 61,700 53 ⑧ Liquid phase 86 - 15,200 65 ⑨ Liquid phase 49 - 49,800 - ⑩ Liquid phase 72 - 49,800 - ⑪ weather 140 3.6 1,930 - ⑫ Liquid phase 140 3.6 1,930 - ⑬ weather 130 2.5 1,090 -

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

10: Hygroscopic salt solution supply line 20: Circulating water supply line
30: water vapor supply line 40: stack
110: Absorption column 111: Rare earth ball layer
112: hygroscopic salt solution supply nozzle 113: air ejector
120: hygroscopic salt solution tank 130: first heat exchanger
140: second heat exchanger 150: third heat exchanger
160: Vortex filter 170: Phase separator
180: distilled water storage tank

Claims (11)

An absorption tower for contacting exhaust gas with a hygroscopic salt solution to recover moisture and latent heat in the exhaust gas and to absorb contaminants in the exhaust gas;
A hygroscopic salt solution storage tank into which the hygroscopic salt solution in contact with the exhaust gas flows;
A first heat exchanger for heat-exchanging at least a part of the hygroscopic salt solution in the hygroscopic salt solution storage tank and the circulating water to heat the circulating water; And
And a second heat exchanger for reheating the circulating water heated by the first heat exchanger by using water vapor separated from the hygroscopic salt solution in the hypochromic hygroscopic salt solution reservoir,
Wherein one end of the first heat exchanger is connected to a hygroscopic salt solution supply line and the other end is connected to a circulating water supply line, the hygroscopic salt solution in the hygroscopic salt solution reservoir is supplied to the hygroscopic salt solution supply line,
Wherein the hygroscopic salt solution supply line and the circulation water supply line intersect each other in the first heat exchanger, the heat of the hygroscopic salt solution is transferred to the circulation water, and the heated circulation water is circulated through the first heat exchanger Lt; / RTI >
One end of the second heat exchanger is connected to the circulating water supply line extending from the first heat exchanger and the other end of the second heat exchanger is connected to the steam exhaust end of the phase separator,
The phase separator separates at least a portion of the hygroscopic salt solution in the hygroscopic salt solution reservoir into water vapor and liquid, and the separated water vapor is passed through the water vapor discharge end disposed at one side of the phase separator, And then,
Wherein the circulation water supply line and the steam supply line intersect each other in the second heat exchanger and the circulation water of the circulation water supply line is further heated by steam of the steam supply line. Recovery of waste heat of gas and reduction of white smoke. The method according to claim 1,
And a hygroscopic salt solution supply nozzle disposed at an upper end of the absorption tower for supplying the hygroscopic salt solution. The method according to claim 1,
And a rare-earth ball layer disposed in the absorber for primary contact with the exhaust gas to adsorb pollutants in the exhaust gas and to decompose the organic matter in the pollutants. And a white smoke abatement device. The method according to claim 1,
Wherein the hygroscopic salt solution contains an aqueous solution of hygroscopic salts. 5. The method of claim 4,
The hygroscopic salts include calcium nitrate (Ca (NO ₃ ) ₂ ), ammonium nitrate (NH ₄ NO ₃ ), ammonium sulfate ((NH ₄ ) ₂ SO ₄ ), barium perchlorate (Ba (ClO ₄ ) ₂ ) (KHCO _3), sodium nitrate (NaNO _3), sodium chlorate (NaClO _3), potassium nitrate (KNO _3), barium nitrate _{(Ba (NO 3) 2)} , sodium perchlorate (NaClO _4), sodium chloride (NaCl), calcium chloride (CaCl ₂ ), potassium formate (CHKO ₂ ), hydrates thereof, or a combination thereof. The method of claim 3,
Wherein the rare earth ball layer is an aggregate of rare earth balls and the rare earth balls are ceramic carriers containing rare earths and the rare earths are contained in the ceramic carrier in an amount of 0.1 to 0.5 wt% And a white smoke abatement device. The method according to claim 1,
Wherein the concentration of the hygroscopic salts in the hygroscopic salt solution is 40 to 80 wt%. The method according to claim 1,
And an air ejector disposed at one side of the absorber for supplying low-temperature, high-pressure air to the absorber in relation to the temperature and pressure of the exhaust gas to induce condensation of the exhaust gas. Recovery and white smoke abatement device. 3. The method of claim 2,
Wherein the hygroscopic salt solution supply line extends to the hygroscopic salt solution supply nozzle through the first heat exchanger and the hygroscopic salt solution which has been heated by the first heat exchanger is supplied to the hygroscopic salt solution supply nozzle Waste heat recovery of exhaust gas and reduction of white smoke. The method according to claim 1,
Further comprising a distilled water storage tank into which condensed water of the steam discharged from the second heat exchanger flows. The method according to claim 1,
A third heat exchanger for contacting at least a part of the hygroscopic salt solution in the hygroscopic salt solution storage tank with another circulating water to heat the separate circulating water and to cool the hygroscopic salt solution;
Further comprising a vortex filter for removing contaminants contained in the cooled hygroscopic salt solution discharged from the third heat exchanger.

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