Precise ammonia spraying system

Abstract

The utility model discloses a precise ammonia spraying system which comprises an SCR reactor smoke inlet pipe shell, a nitrogen oxide content detection device and a gas flow detection device are installed at the head end and the tail end of the SCR reactor smoke inlet pipe shell respectively, and a water curtain type precise ammonia spraying device is fixedly installed at the middle end of the SCR reactor smoke inlet pipe shell. According to the precise ammonia spraying system, the nitrogen oxide gas detector I is used for monitoring the content of nitrogen oxide entering the inlet of the smoke inlet pipe shell of the SCR reactor in real time, and transmitting data information monitored by the nitrogen oxide gas detector I in real time to the servo motor, so that the rotating speed of an output shaft of the servo motor is controlled, and the content of a supplemented urea solution is controlled; the amount of ammonia gas decomposed by urea is accurately controlled in the later period, so that the ammonia gas feeding can be accurately controlled along with the change of the content of nitrogen oxide in soot, excessive emission of ammonia gas or low denitration efficiency is avoided, and the purpose of accurate ammonia spraying is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of precise ammonia spraying, in particular to a precise ammonia spraying system. Background Art

[0002] In the cement production process, when the SCR reactor is used to denitrify the soot, the reducing agent used for denitrification can be ammonia or urea solution. When urea is heated to 160°C, it will decompose to produce ammonia and cyanic acid. The reacted soot and the denitrifying agent produce a series of chemical reactions, so that the nitrogen oxides are reduced to nitrogen and water; that is, the above-mentioned ammonia or urea solution is mainly used to add ammonia to the SCR reactor.

[0003] In the traditional ammonia injection process, due to the imprecise control in the coal smoke, it often leads to excessive ammonia emission or unattained denitrification efficiency, which not only pollutes the air, but also further aggravates environmental problems. That is, the nitrogen oxides in the existing coal smoke are unevenly distributed, and the ammonia injection cannot be accurately controlled as the nitrogen oxide content in the coal smoke changes. This paper aims to propose a precise ammonia injection system. Utility Model Content

[0004] The utility model aims to solve the problem in the prior art that nitrogen oxides in coal smoke are unevenly distributed and ammonia injection cannot be accurately controlled as the nitrogen oxide content in coal smoke changes, and proposes a precise ammonia injection system.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A precise ammonia injection system, comprising an SCR reactor smoke inlet pipe housing, wherein a nitrogen oxide content detection device and a gas flow detection device are installed at both ends of the SCR reactor smoke inlet pipe housing;

[0007] A water curtain type precision ammonia spraying device is fixedly installed at the middle end of the smoke inlet pipe shell of the SCR reactor.

[0008] Preferably, the water curtain type precision ammonia spraying device comprises an L-shaped shell, roller one, roller two, roller three and roller four, roller one and roller two are both rotatably installed in the lower end inner cavity of the L-shaped shell, roller three and roller four are both rotatably installed in the upper end inner cavity of the L-shaped shell, and the peripheries of roller one and roller three, roller two and roller four are all provided with isolation mesh belt rings.

[0009] Preferably, the isolation mesh belt ring is provided with a plurality of densely arranged fine holes, two rubber blocks 1 and two rubber blocks are fixedly installed in the inner cavity of the lower end of the L-shaped shell, two rubber blocks 2 are fixedly installed in the inner cavity of the upper end of the L-shaped shell, and an injection port is fixedly connected to the upper end of one side of the L-shaped shell, and a wire plug is provided at the upper end of the injection port.

[0010] Preferably, the ends of the roller three and the roller four both pass through the L-shaped shell, and gears are fixedly installed at the ends of the roller three and the roller four, and the two gears are meshed with each other. A motor is installed on one side of the L-shaped shell through a bracket, and the output shaft of the motor is fixedly connected to one of the gears through a coupling.

[0011] Preferably, the nitrogen oxide content detection device includes a nitrogen oxide gas detector 1 and a nitrogen oxide gas detector 2, and the nitrogen oxide gas detector 1 and the nitrogen oxide gas detector 2 are respectively fixedly installed at the inlet and outlet of the smoke inlet pipe shell of the SCR reactor.

[0012] Preferably, the gas flow detection device comprises a flue gas flow meter 1 and a flue gas flow meter 2, and the flue gas flow meter 1 and the flue gas flow meter 2 are respectively fixedly installed at the inlet and outlet of the smoke inlet pipe shell of the SCR reactor.

[0013] Compared with the prior art, the utility model provides a precise ammonia spraying system, which has the following beneficial effects:

[0014] 1. The precise ammonia injection system uses a nitrogen oxide gas detector to monitor the nitrogen oxide content entering the inlet of the SCR reactor smoke inlet shell in real time, and transmits the data information monitored by the nitrogen oxide gas detector in real time to the servo motor to control the speed of the servo motor output shaft to control the content of the supplementary urea solution, so as to achieve precise control of the amount of ammonia decomposed by urea in the later stage, thereby realizing that the ammonia delivery can be accurately controlled as the nitrogen oxide content in the coal smoke changes, avoiding excessive ammonia emissions or low denitrification efficiency, and achieving the purpose of precise ammonia injection.

[0015] 2. The precise ammonia spraying system, through the faster rotation speed of the output shaft of the servo motor, and the kinetic energy transmission of the two mutually meshing gears, roller three and roller four, is used to drive the left isolation mesh belt ring to rotate counterclockwise and the right isolation mesh belt ring to rotate clockwise, so that the lower ends of the two isolation mesh belt rings continuously dip into the urea solution in the inner cavity of the lower end of the L-shaped shell, and form a solution film in several pores on the isolation mesh belt ring, and with the rotation of the two isolation mesh belt rings, the broken solution film will re-form a new solution film in the gap between the two isolation mesh belt rings, that is, a uniform urea solution film can be formed on the two isolation mesh belt rings, so that the urea solution on the two isolation mesh belt rings is uniformly and fully mixed with the incoming coal smoke, effectively avoiding the low denitrification efficiency caused by uneven mixing of urea solution and coal smoke. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural schematic diagram of a precise ammonia injection system proposed by the utility model;

[0017] Figure 2 A cross-sectional view of a water curtain type precision ammonia spraying device in a precision ammonia spraying system proposed by the utility model Figure 1 ;

[0018] Figure 3 A cross-sectional view of a water curtain type precision ammonia spraying device in a precision ammonia spraying system proposed by the utility model Figure 2 .

[0019] In the figure: 1. SCR reactor smoke inlet pipe shell; 2. Nitrogen oxide gas detector 1; 3. Water curtain type precision ammonia spray device; 301. L-shaped shell; 302. Thread plug; 303. Servo motor; 304. Gear; 305. Bracket; 306. Liquid injection port; 307. Roller 1; 308. Roller 2; 309. Isolation mesh belt ring; 310. Rubber block 1; 311. Rubber block 2; 312. Roller 3; 313. Roller 4; 314. Rubber block; 4. Nitrogen oxide gas detector 2; 5. Flue gas flow meter 1; 6. Flue gas flow meter 2. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0021] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0022] Reference Figure 1-3 , a precise ammonia injection system, comprising an SCR reactor smoke inlet pipe shell 1, both ends of the SCR reactor smoke inlet pipe shell 1 are equipped with a nitrogen oxide content detection device and a gas flow detection device, the nitrogen oxide content detection device comprises a nitrogen oxide gas detector 1 2 and a nitrogen oxide gas detector 2 4, the nitrogen oxide gas detector 1 2 and the nitrogen oxide gas detector 2 4 are respectively fixedly installed at the inlet and outlet of the SCR reactor smoke inlet pipe shell 1, the nitrogen oxide gas detector 1 2 and the nitrogen oxide gas detector 2 4 are mainly used for real-time online monitoring of the nitrogen oxide content at the inlet and outlet of the SCR reactor smoke inlet pipe shell 1, the gas flow detection device comprises a flue gas flow meter 1 5 and a flue gas flow meter 2 6, the flue gas flow meter 1 5 and the flue gas flow meter 2 6 are respectively fixedly installed at the inlet and outlet of the SCR reactor smoke inlet pipe shell 1, the flue gas flow meter 1 5 and the flue gas flow meter 2 6 are used for real-time online monitoring of the gas flow at the inlet and outlet of the SCR reactor smoke inlet pipe shell 1;

[0023] The data monitored in real time by the flue gas flow meter 1 5 and the flue gas flow meter 2 6 are used to calculate the flue gas flow difference at the inlet and outlet of the SCR reactor smoke inlet pipe shell 1, and the increased flue gas content at the outlet of the SCR reactor smoke inlet pipe shell 1. Combined with the nitrogen oxide gas detector 1 2 and the nitrogen oxide gas detector 2 4 to monitor the nitrogen oxide content in real time, the urea solution content supplemented by the water curtain type precision ammonia injection device 3 at the middle end of the SCR reactor smoke inlet pipe shell 1 can be calculated.

[0024] In the present embodiment, a water curtain type precision ammonia spraying device 3 is fixedly installed at the middle end of the SCR reactor smoke inlet pipe shell 1, and the water curtain type precision ammonia spraying device 3 includes an L-shaped shell 301, and the L-shaped shell 301 is L-shaped as a whole, and the left and right sides of the L-shaped shell 301 are provided with openings that are interconnected with the inner cavity of the SCR reactor smoke inlet pipe shell 1, that is, the L-shaped shell 301 is fixedly connected and installed at the middle end of the SCR reactor smoke inlet pipe shell 1, and a liquid injection port 306 is fixedly installed at the upper end of one side of the L-shaped shell 301, and a screw plug 302 is threadedly installed on the upper end of the liquid injection port 306.

[0025] In this embodiment, the inner cavity part of the L-shaped shell 301 at the lower end of the SCR reactor smoke inlet pipe shell 1 is used to hold the urea solution. The lower end of the inner cavity of the SCR reactor smoke inlet pipe shell 1 is rotatably installed with a roller 1 307 and a roller 2 308 parallel to each other. The roller 1 307 and the roller 2 308 are arranged in the urea solution held at the lower end of the inner cavity of the L-shaped shell 301. The roller 3 312 and the roller 4 313 are respectively arranged directly above the roller 1 307 and the roller 2 308. The roller 3 312 and the roller 4 313 are respectively rotatably installed on the upper end of the L-shaped shell 301.

[0026] In this embodiment, the peripheries of the roller 1 307 and the roller 3 312, the roller 2 308 and the roller 4 313 are all extruded and wrapped with isolation mesh belt rings 309, and the two isolation mesh belt rings 309 are parallel to each other. Figure 3 The spacing between the two isolation mesh belt rings 309 is less than 1 mm, which makes it easy to form a solution film. Secondly, the isolation mesh belt ring 309 is made of high-temperature resistant rubber material, and a number of densely arranged pores are arranged on the isolation mesh belt ring 309. The inner diameter of the pores is less than 1 mm. After being immersed in the urea solution, it is easy to form a solution film.

[0027] In this embodiment, two rubber blocks 2 311 and two rubber blocks 1 310 are respectively arranged at the upper and lower ends of the left side of the left isolation mesh belt ring 309 and the right side of the right isolation mesh belt ring 309, the two rubber blocks 2 311 are respectively fixedly mounted on the left and right inner walls of the upper end of the L-shaped shell 301, and the two rubber blocks 1 310 are respectively fixedly mounted on the left and right inner walls of the lower end of the L-shaped shell 301, the distance between the rubber block 2 311 and the rubber block 1 310 and the isolation mesh belt ring 309 is less than 1 mm, and two rubber blocks 314 are arranged between the two rubber blocks 1 310;

[0028] The two rubber blocks 1 310 and the two rubber blocks 314 are mainly used to cover the top of the urea solution at the lower end of the inner cavity of the L-shaped shell 301 to reduce the volatilization of the urea solution. The front and rear ends of the rubber block 314 are respectively fixedly installed on the inner wall of the L-shaped shell 301. The two rubber blocks 314 are arranged between the two isolation mesh belt rings 309, and the distance between the inner wall of the isolation mesh belt ring 309 and the rubber block 314 is less than 1 mm. The upper and lower ends are respectively provided with a rubber block 2 311 and a rubber block 1 310.

[0029] In this embodiment, the ends of the roller three 312 and the roller four 313 are both extended out of the L-shaped housing 301, and the ends of the roller three 312 and the roller four 313 are both fixedly installed with gears 304, the gears 304 are arranged on the outside of the L-shaped housing 301, and the two gears 304 are meshed with each other, a bracket 305 is fixedly installed on one side of the L-shaped housing 301, a servo motor 303 is fixedly installed on the upper end of the bracket 305, and the output shaft of the servo motor 303 is coaxially fixedly connected with the gear 304 on the roller four 313 through a coupling;

[0030] The nitrogen oxide gas detector 12, the nitrogen oxide gas detector 24, the flue gas flow meter 15, the flue gas flow meter 26 and the servo motor 303 are all connected to the external power supply through wires, and the nitrogen oxide gas detector 12, the nitrogen oxide gas detector 24, the flue gas flow meter 15, the flue gas flow meter 26 and the servo motor 303 are connected to the online monitoring analyzer through wires. When the servo motor 303 is working, Figure 3 The output shaft of the servo motor 303 drives the roller four 313 to rotate clockwise through a gear 304, and drives the roller three 312 to rotate counterclockwise through another mutually meshing gear 304, thereby driving the isolation net belt ring 309 on the left to rotate counterclockwise and the isolation net belt ring 309 on the right to rotate clockwise.

[0031] In the present utility model, the ammonia spraying process of the precise ammonia spraying system is as follows:

[0032] Step 1: monitor the nitrogen oxide content entering the inlet of the smoke inlet pipe shell 1 of the SCR reactor in real time through the nitrogen oxide gas detector 2, and transmit the data information monitored in real time by the nitrogen oxide gas detector 2 to the servo motor 303, which is used to control the rotation speed of the output shaft of the servo motor 303 to control the content of the supplementary urea solution, so as to achieve the precise control of the amount of ammonia decomposed by urea in the later stage, thereby realizing that the ammonia delivery can be precisely controlled as the nitrogen oxide content in the coal smoke changes, avoiding excessive ammonia emission or low denitrification efficiency, and achieving the purpose of precise ammonia injection;

[0033] The faster the output shaft of the servo motor 303 rotates, the kinetic energy of the two meshing gears 304, the roller three 312, and the roller four 313 is transmitted to drive the left isolation mesh belt ring 309 to rotate counterclockwise and the right isolation mesh belt ring 309 to rotate clockwise, so that the lower ends of the two isolation mesh belt rings 309 continuously dip into the urea solution in the inner cavity at the lower end of the L-shaped shell 301, and form a solution film in several pores on the isolation mesh belt ring 309, and then as the soot passes through the several pores and the solution film in the two isolation mesh belt rings 309, the soot and the urea solution are fully combined. And the broken solution film, along with the rotation of the two isolation mesh belt rings 309, will re-form a new solution film in the gap between the two isolation mesh belt rings 309, that is, a uniform urea solution film will be formed on the two isolation mesh belt rings 309, and the urea solution and soot will be fully mixed. Moreover, the faster the output shaft of the servo motor 303 rotates, the more urea solution will be carried upward per unit time, that is, by controlling the rotation speed of the output shaft of the servo motor 303, the injection amount of the urea solution can be controlled, so as to achieve the later stage of accurately controlling the amount of ammonia decomposed when the urea is heated to 160°C;

[0034] Step 2: Use the nitrogen oxide gas detector 2 4 to monitor the nitrogen oxide content entering the outlet of the SCR reactor smoke inlet pipe shell 1 in real time, and combine the data monitored in real time by the nitrogen oxide gas detector 2 to calculate the change in nitrogen oxides in the coal smoke. Secondly, cooperate with the real-time monitoring data of the flue gas flow meter 1 5 and the flue gas flow meter 2 6, and then use the online monitoring analyzer to calculate the flue gas flow difference at the inlet and outlet of the SCR reactor smoke inlet pipe shell 1, the difference between the flue gas flow difference and the nitrogen oxide content, which are used to assist in calculating the content of the supplementary urea solution.

[0035] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A precision ammonia injection system, comprising an SCR reactor smoke inlet pipe housing (1), characterized in that: A nitrogen oxide content detection device and a gas flow detection device are installed at both ends of the SCR reactor smoke inlet pipe shell (1); A water curtain type precision ammonia spraying device (3) is fixedly installed at the middle end of the SCR reactor smoke inlet pipe housing (1).

2. A precise ammonia injection system according to claim 1, characterized in that: The water curtain type precision ammonia spraying device (3) comprises an L-shaped shell (301), a first roller (307), a second roller (308), a third roller (312) and a fourth roller (313), wherein the first roller (307) and the second roller (308) are both rotatably mounted in the inner cavity at the lower end of the L-shaped shell (301), and the third roller (312) and the fourth roller (313) are both rotatably mounted in the inner cavity at the upper end of the L-shaped shell (301), and the peripheries of the first roller (307) and the third roller (312), and the peripheries of the second roller (308) and the fourth roller (313) are all provided with isolation mesh belt rings (309).

3. A precise ammonia injection system according to claim 2, characterized in that: The isolation mesh belt ring (309) is provided with a plurality of densely arranged fine holes, two rubber blocks 1 (310) and two rubber blocks (314) are fixedly installed in the inner cavity at the lower end of the L-shaped shell (301), and two rubber blocks 2 (311) are fixedly installed in the inner cavity at the upper end of the L-shaped shell (301), and an upper end of one side of the L-shaped shell (301) is fixedly connected to a liquid injection port (306), and a thread plug (302) is provided at the upper end of the liquid injection port (306).

4. A precise ammonia injection system according to claim 2, characterized in that: The ends of the roller three (312) and the roller four (313) are both extended out of the L-shaped housing (301), and gears (304) are fixedly installed on the ends of the roller three (312) and the roller four (313), and the two gears (304) are meshed with each other. A motor (303) is installed on one side of the L-shaped housing (301) through a bracket (305), and the output shaft of the motor (303) is fixedly connected to one of the gears (304) through a coupling.

5. The precise ammonia injection system according to claim 1, characterized in that: The nitrogen oxide content detection device comprises a nitrogen oxide gas detector 1 (2) and a nitrogen oxide gas detector 2 (4), wherein the nitrogen oxide gas detector 1 (2) and the nitrogen oxide gas detector 2 (4) are respectively fixedly installed at the inlet and outlet of the smoke inlet pipe shell (1) of the SCR reactor.

6. The precise ammonia injection system according to claim 1, characterized in that: The gas flow detection device comprises a flue gas flow meter 1 (5) and a flue gas flow meter 2 (6), wherein the flue gas flow meter 1 (5) and the flue gas flow meter 2 (6) are respectively fixedly installed at the inlet and outlet of the SCR reactor smoke inlet pipe shell (1).

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