Multi-cyclone integrated SCR system

Abstract

The present invention relates to a multi-cyclone integrated SCR system having a new configuration, wherein the inside of a housing is divided into a dust collection space having a plurality of cyclones and a denitrification space having an SCR catalyst layer to simultaneously remove dust and nitrogen oxides contained in exhaust gas, the dust collection effect is excellent due to the cyclones and a reducing agent is uniformly dispersed to improve the denitrification effect, and the multi-cyclone integrated SCR system is compact and space-efficient.

Description

Multi-cyclone integrated SCR system

[0001] The present invention relates to a multi-cyclone integrated SCR system, and more specifically, to a new multi-cyclone integrated SCR system having an excellent dust collection and denitrification effect, capable of simultaneously removing dust and nitrogen oxides contained in exhaust gas.

[0002] Exhaust gases emitted from power plants, incinerators, cement manufacturing facilities, etc. contain nitrogen oxides, so most of them are denitrified and discharged using an SCR system (Selective Catalytic Reduction System).

[0003] However, exhaust gas contains a large amount of dust along with nitrogen oxides. Therefore, when denitrification of exhaust gas is performed, the dust contained in the exhaust gas adheres to the SCR catalyst of the SCR system, contaminating the SCR catalyst and obstructing the gas flow, thereby reducing the denitrification efficiency. In particular, the exhaust gas generated from the incinerator of a cement manufacturing facility contains a large amount of fly ash, so this problem becomes even more serious when treating exhaust gas generated from such facilities.

[0004] Due to these issues, exhaust gas treatment facilities typically employ an SCR system attached to the rear of a cyclone. This system first removes particulate matter from the exhaust gas, followed by denitrification using the SCR system. However, these conventional exhaust gas treatment facilities, with their large size due to the SCR system attached to the rear of the cyclone, have the disadvantage of taking up a lot of space.

[0005] In addition, in the SCR system, the reducing agent must be evenly supplied to the SCR catalyst to improve the denitrification efficiency. Therefore, in the past, a mixer was added behind the reducing agent spray nozzle in the exhaust line, or a baffle or distributor was installed in the SCR system to evenly distribute the reducing agent in the exhaust gas.

[0006] The present invention has been proposed in view of the above problems, and the purpose of the present invention is to provide a new cyclone multi-integrated SCR system having a compact structure that can simultaneously remove dust and nitrogen oxides contained in exhaust gas by dividing the inside of the housing into a dust collection space equipped with a plurality of cyclones and a denitrification space equipped with an SCR catalyst layer, and that has an excellent dust collection effect by the cyclones, an even distribution of reducing agent, and an improved denitrification effect, and is compact and has high space utilization.

[0007] According to a feature of the present invention, a housing (100) is formed with an inlet (110) formed at one side of the lower portion through which exhaust gas flows in, an exhaust port (120) formed at the upper portion through which purified gas is discharged, and a dust discharge port (130) formed at the lower portion through which dust collected from the exhaust gas is discharged;

[0008] A partition wall (200) that divides the internal space of the housing (100) into a dust collection space (A) communicated with the inlet (110) and a denitrification space (B) communicated with the exhaust port (120);

[0009] A plurality of cyclones (300) each having an outer cylinder (310) formed with a cylindrical portion (312) having an inlet (311) and a conical portion (314) extending downward from the cylindrical portion (312) and having an open bottom, and an outlet pipe (320) having a lower end inserted into the outer cylinder (310) and an upper end protruding out of the outer cylinder (310), such that the inlet (311) is positioned in the dust collection space (A) and the outlet pipe (320) is installed to communicate with the denitrification space (B);

[0010] An SCR catalyst layer (400) located above the cyclone (300) and installed across the denitrification space (B) to remove nitrogen oxides contained in the gas discharged through the outlet pipe (320) of the cyclone (300); and

[0011] An air injection nozzle (500) is installed to be positioned in the above denitrification space (B) and sprays compressed air onto the SCR catalyst layer (400) to remove dust attached to the SCR catalyst layer (400);

[0012] A multi-cyclone integrated SCR system is provided, characterized in that a passage (S) is formed inside the housing (100) to connect the denitrification space (B) with the dust discharge port (130), so that dust falling from the denitrification space (B) is discharged to the dust discharge port (130).

[0013] According to another feature of the present invention, a guide vane (330) is formed at the inlet (311) of the cyclone (300) to be curved inwardly and to generate a swirling flow of fluid.

[0014] According to another feature of the present invention, the partition wall (200) includes an upper surface (210) and a lower surface (220) arranged vertically with the inlet (110) therebetween, an installation hole (222) in which the cyclone (300) is installed is formed in the lower surface (220), a through hole (212) communicating with the outlet pipe (320) is formed in the upper surface (210), and the cyclone (300) is installed in the installation hole so that the open lower end of the cone portion (314) protrudes below the lower surface (220), so that dust collected in the cyclone (300) falls to the open lower end of the cone portion (314) and is discharged to the dust discharge port (130).

[0015] According to another feature of the present invention, the passage (S) is positioned opposite the inlet (110) with the dust collection space (A) therebetween, and the upper surface (210) is formed as a slope that becomes downward as it approaches the passage (S) from the inlet (110).

[0016] The present invention as described above has the following effects.

[0017] First, since the interior of the housing (100) is divided into a dust collection space (A) where a cyclone (300) is installed and a denitrification space (B) where an SCR catalyst layer (400) is installed, the exhaust gas is first subjected to dust collection treatment through the cyclone (300) and then denitrification treatment through the SCR catalyst layer (400). Accordingly, the life of the SCR catalyst layer (400) is extended and the denitrification efficiency is prevented from being reduced by dust.

[0018] Second, compared to conventional exhaust gas treatment facilities with separate cyclones and SCR systems, the configuration is compact and the volume is reduced, so it does not take up much installation space, resulting in excellent space utilization.

[0019] Third, since multiple cyclones are arranged in parallel to divide the air volume and discharge it into the denitrification space (B), the reducing agent is evenly supplied to the SCR catalyst layer (400). Therefore, the denitrification effect is improved because the reducing agent is evenly distributed and supplied to the SCR catalyst layer (400) without additionally installing a separate means to evenly distribute the reducing agent.

[0020] Fourth, since the cyclone (300) is equipped with a guide vane (330), a strong air current rotating at high speed is formed inside the cyclone (300), so the dust collection effect is excellent.

[0021] Fifth, since the dust discharged from the cyclone (300) and the dust removed from the SCR catalyst layer (400) are discharged through a single dust discharge port (130), it has the advantage of being easy to collect dust.

[0022] Figure 1 is a cross-sectional view of a preferred embodiment of the present invention.

[0023] Figure 2 is a partially enlarged cross-sectional view of the above embodiment.

[0024] Figure 3 is a perspective view of the cyclone used in the above embodiment.

[0025] Figure 4 is a plan view of the above cyclone.

[0026] Figure 5 is a cross-sectional view showing the gas and dust flow of the above embodiment.

[0027] Figure 6 is a cross-sectional view of another embodiment of the present invention.

[0028] The present invention is described in more detail below.

[0029] 1 to 4 are cross-sectional views and perspective views of preferred embodiments of the present invention, and FIG. 5 is a cross-sectional view showing the gas and dust flow of this embodiment. As shown, the present invention includes a housing (100) having an inlet (110) formed on one side of the lower portion through which exhaust gas flows and an exhaust port (120) and a dust discharge port (130) formed on the upper and lower portions, respectively, a partition wall (200) dividing the internal space of the housing (100) into a dust collection space (A) and a denitrification space (B), a plurality of cyclones (300) installed so that the inlet (311) is positioned in the dust collection space (A), an SCR catalyst layer (400) installed in the denitrification space (B), and an air injection nozzle (500) for injecting compressed air into the SCR catalyst layer (400).

[0030] The above housing (100) has a vertically long tower shape, and an inlet (110) for introducing exhaust gas is formed on one side of the lower portion, an exhaust port (120) for discharging purified gas is formed on the upper portion, and a dust discharge port (130) for discharging dust collected from the exhaust gas is formed on the lower portion. The exhaust port (120) and the dust discharge port (130) have a hopper shape that is tapered upward and downward, respectively.

[0031] The inlet (110) of the housing (100) is connected to the exhaust line (10) of an exhaust gas emission facility such as a power plant, an incinerator, a cement manufacturing facility, etc., and the exhaust line (10) is equipped with a reducing agent injection nozzle (20) that injects a reducing agent such as urea water or ammonia into the exhaust gas. Accordingly, the exhaust gas mixed with the reducing agent injected from the reducing agent injection nozzle (20) flows into the housing (100) through the inlet (110).

[0032] And the above-mentioned partition wall (200) is installed inside the housing (100) to divide the internal space of the housing (100) into a dust collection space (A) that is connected to the inlet (110) and a denitrification space (B) that is connected to the exhaust port (120) and the dust discharge port (130). More specifically, as illustrated, this partition wall (200) is composed of an upper surface (210) and a lower surface (220) which are arranged to face each other upwardly and downwardly with an inlet (110) therebetween, and a side surface (230) which connects the periphery of the upper surface (210) and the lower surface (220). When the dust collection space (A) completely crosses the inside of the housing (100), the denitrification space (B) is connected to the exhaust port (120) and not to the dust discharge port (130). Therefore, the side surface (230) of the partition wall (200) is formed to be spaced apart from one wall of the housing (100), so that a passage (S) is formed on one side of the dust collection space (A) to connect the denitrification space (B) to the dust discharge port (130). Preferably, as illustrated, the passage (S) is positioned opposite the inlet (110) with the dust collection space (A) interposed therebetween.

[0033] In particular, preferably, the upper surface (210) of the bulkhead (200) is formed to slope downward as it approaches the passage (S) from the inlet (110). When the upper surface (210) is formed to slope in this way, as described later, the dust that is removed from the SCR catalyst layer (400) and falls can flow down the upper surface (210) and smoothly fall to the dust discharge port (130) through the passage (S). In the present embodiment, the lower end of the side surface (230) of the bulkhead (200) is exemplified as extending downward further than the bottom surface (220).

[0034] On the bottom surface (220) of this bulkhead (200), installation holes (222) for installing a cyclone (300) are arranged at regular intervals, and on the top surface (210), through holes (212) that communicate with the outlet pipe (320) of the cyclone (300) are arranged.

[0035] And the above cyclone (300) is formed by including an outer cylinder (310) formed with a cylindrical portion (312) having an inlet (311) formed at the upper end and a conical portion (314) extending from the cylindrical portion (312) in a conical shape and having an open lower end, and an outlet pipe (320) having a lower end inserted into the outer cylinder (310) and an upper end protruding out of the outer cylinder (310), and a guide vane (330) that is curved inwardly to generate a swirling flow of fluid is provided at the inlet (311) of the outer cylinder (310).

[0036] This cyclone (300) is installed on the bottom surface (220) of the partition wall (200) so that the outlet pipe (320) is connected to the through hole (212) formed on the upper surface (220) of the partition wall (200) and the inlet (311) is located in the dust collection space (A). When the cyclone (300) is installed in this manner, the lower end of the cone portion (314) protrudes below the bottom surface (220) of the partition wall (200). Therefore, the exhaust gas flowing into the inlet (110) of the housing (100) flows into the cyclone (300), where the dust contained in the exhaust gas is captured and primarily removed, and the captured dust falls to the bottom of the outer tube (310) of the cyclone (300) and is discharged through the dust discharge port (130). And the gas from which dust has been primarily removed is discharged to the denitrification space (B) through the outlet pipe (320) of the cyclone (300). In particular, if the cyclone (300) is equipped with guide vanes (330), a strong air current rotating at high speed is formed in the cyclone (300), thereby improving the dust collection effect. In this embodiment, three guide vanes (330) are exemplified, but the number of guide vanes (330) is not limited to this, and the greater the number of guide vanes (330), the stronger the air current is formed.

[0037] Meanwhile, the SCR catalyst layer (400) is positioned above the cyclone (300) and installed to cross the denitrification space (B), so that the gas discharged through the outlet pipe (320) of the cyclone (300) and introduced into the denitrification space (B) is denitrified while passing through the SCR catalyst layer (400) and is discharged through the exhaust port (120). Preferably, the SCR catalyst layer (400) is formed in the form of a cartridge in which the SCR catalyst is accommodated in a cage, and is installed in multiple stages so as to be spaced apart vertically as shown.

[0038] And the above air injection nozzle (500) is located in the denitrification space (B) and injects compressed air in the reverse direction of the gas flow to the SCR catalyst layer (400). When compressed air is injected to the SCR catalyst layer (400), dust attached to the SCR catalyst layer (400) is removed and falls downward. In the present embodiment, the air injection nozzle (500) is positioned above the SCR catalyst layer (400) and is exemplified as injecting compressed air downward, i.e., in the reverse direction of the gas flow. However, in some cases, the air injection nozzle (500) may be positioned below the SCR catalyst layer (400) and configured to inject compressed air in the forward direction of the gas flow, or the air injection nozzle (500) may be provided on both the upper and lower sides of the SCR catalyst layer (400) and configured to inject compressed air in the forward and reverse directions of the gas flow.

[0039] The dust falling from the SCR catalyst layer (400) is discharged to the dust discharge port (130) through the passage (S) or falls to the upper surface (210) of the partition wall (200), flows down along the upper surface (210), and is discharged to the dust discharge port (130) through the passage (S). In this embodiment, it is exemplified that an air injection nozzle (500) is additionally installed on the upper surface (210) of the partition wall (200). In this case, the dust falling to the upper surface (210) is more effectively discharged to the passage (S) by the compressed air injected from the air injection nozzle (500).

[0040] The operation of the present invention having the above configuration is as follows.

[0041] The exhaust gas discharged from the exhaust gas emission facility is mixed with a reducing agent sprayed from a reducing agent spray nozzle (20), and the exhaust gas mixed with the reducing agent flows into the dust collection space (A) of the housing (100), where dust is first removed in a cyclone (300) and then discharged to the denitrification space (B) through the outlet pipe (320) of the cyclone (300). Since the cyclone (300) is equipped with a guide vane (330) to form a strong air current, not only is the dust collection effect of the cyclone (300) itself excellent, but since a plurality of such cyclones (300) are provided, a high dust collection effect can be expected.

[0042] The dust collected in the cyclone (300) falls to the bottom of the outer tube (310) of the cyclone (300) and is discharged to the outside of the housing (100) through the dust discharge port (130). Then, the gas discharged to the denitrification space (B) through the outlet pipe (320) of the cyclone (300) moves upward and undergoes denitrification while passing through the SCR catalyst layer (400). In particular, since the air volume is divided by the cyclones (300) and discharged to the denitrification space (B), the reducing agent is evenly supplied to the SCR catalyst layer (400), thereby improving the denitrification effect.

[0043] Meanwhile, as the present invention is operated in this manner, dust gradually accumulates on the SCR catalyst layer (400), so the air injection nozzle (500) is operated at regular intervals to remove dust attached to the SCR catalyst layer (400). When compressed air is injected from the air injection nozzle (500), dust attached to the SCR catalyst layer (400) is removed and falls, and the falling dust falls into a passage (S) formed on one side of the partition wall (200) and is discharged to the dust discharge port (130), or falls to the upper surface (210) of the partition wall (200), flows down the upper surface (210), and is discharged to the dust discharge port (130).

[0044] Dust discharged through the dust discharge outlet (130) is recycled or disposed of. In particular, dust contained in the exhaust gas generated during the cement manufacturing process can be recycled for various purposes as fly ash. Therefore, when processing exhaust gas generated during the cement manufacturing process, dust discharged through the dust discharge outlet (130), i.e. fly ash, is collected and recycled.

[0045] The present invention having the above configuration is characterized in that the exhaust gas undergoes primary dust collection through a cyclone (300) and then undergoes denitrification through an SCR catalyst layer (400), so that the lifespan of the SCR catalyst layer (400) is extended and the denitrification efficiency is prevented from being reduced by dust. In addition, compared to conventional exhaust gas treatment facilities in which the cyclone and the SCR system are configured separately, the configuration is compact and thus has the advantage of excellent space utilization. In addition, since the cyclone (300) is equipped with a guide vane (330) to form a strong air current, the dust collection effect of the cyclone is excellent. In addition, since the air volume is divided by the cyclones (300) arranged in parallel and supplied to the denitrification space (B), the reducing agent is evenly distributed and supplied without adding a separate dispersing device, and therefore the denitrification effect is excellent.

[0046] In addition, since the dust discharged from the cyclone (300) and the dust removed from the SCR catalyst layer (400) are discharged through a single dust discharge port (130), it has the advantage of being easy to collect the dust.

[0047] Below, another embodiment of the present invention is described, but description of the same configuration and effects as the above-described embodiment is omitted.

[0048] Fig. 6 shows another embodiment of the present invention, in which a dust discharge line (140) communicating with the denitrification space (B) is additionally formed on one side of the housing (100).

[0049] Therefore, compressed air is injected from the air injection nozzle (500) and the dust removed from the SCR catalyst layer (400) is discharged to the outside through the dust discharge line (140). Preferably, the dust discharge line (140) is formed to extend from the upper surface (210) of the partition wall (200), so that the dust that falls to the upper surface (210) of the partition wall (200) is discharged more smoothly through the dust discharge line (140).

Claims

1. A housing (100) having an inlet (110) formed on one side of the lower portion through which exhaust gas flows in, an exhaust port (120) formed on the upper portion through which purified gas is discharged, and a dust discharge port (130) formed on the lower portion through which dust collected from the exhaust gas is discharged; A partition wall (200) that divides the internal space of the housing (100) into a dust collection space (A) communicated with the inlet (110) and a denitrification space (B) communicated with the exhaust port (120); A plurality of cyclones (300) each having an outer cylinder (310) formed with a cylindrical portion (312) having an inlet (311) and a conical portion (314) extending downward from the cylindrical portion (312) and having an open bottom, and an outlet pipe (320) having a lower end inserted into the outer cylinder (310) and an upper end protruding out of the outer cylinder (310), such that the inlet (311) is positioned in the dust collection space (A) and the outlet pipe (320) is installed to communicate with the denitrification space (B); An SCR catalyst layer (400) located above the cyclone (300) and installed across the denitrification space (B) to remove nitrogen oxides contained in the gas discharged through the outlet pipe (320) of the cyclone (300); and An air injection nozzle (500) is installed to be positioned in the above denitrification space (B) and sprays compressed air onto the SCR catalyst layer (400) to remove dust attached to the SCR catalyst layer (400); A multi-cyclone integrated SCR system characterized in that a passage (S) is formed inside the housing (100) to connect the denitrification space (B) with the dust discharge port (130), so that dust falling from the denitrification space (B) is discharged to the dust discharge port (130).

2. In paragraph 1, A multi-cyclone integrated SCR system characterized in that a guide vane (330) is formed at the inlet (311) of the above cyclone (300) to be curved inwardly and generate a swirling flow of fluid.

3. In paragraph 1, The above bulkhead (200) includes an upper surface (210) and a lower surface (220) arranged vertically with the inlet (110) in between, and an installation hole (222) in which the cyclone (300) is installed is formed in the lower surface (220), and a through hole (212) communicating with the outlet pipe (320) is formed in the upper surface (210). A multi-cyclone integrated SCR system characterized in that the cyclone (300) is installed in the installation hole (222) so that the open lower end of the cone portion (314) protrudes below the bottom portion (220), and dust captured in the cyclone (300) falls to the open lower end of the cone portion (314) and is discharged to the dust discharge port (130).

4. In paragraph 3, A multi-cyclone integrated SCR system characterized in that the passage (S) is positioned opposite the inlet (110) with the dust collection space (A) in between, and the upper surface (210) is formed as a slope that becomes downward as it approaches the passage (S) from the inlet (110).

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