An air curtain protected L-type urea solution spray gun

Abstract

The invention discloses an L-shaped urea solution spray gun with wind curtain protection, comprising a protective wind cap, an atomizing nozzle and an L-shaped transmission pipe connected to the atomizing nozzle; wherein the L-shaped transmission pipe comprises a nozzle seat, a protective wind pipe, an atomizing wind pipe, a liquid pipe, a protective wind channel, an atomizing wind channel and a liquid channel; the nozzle seat comprises a protective wind channel, an atomizing wind channel and a liquid channel arranged concentrically from the outside to the inside; the protective wind cap and the atomizing nozzle are both arranged on the nozzle seat; the protective wind transmission channel is between the inner wall of the protective wind pipe and the outer wall of the atomizing wind pipe, and one end of the protective wind transmission channel is connected to the inner side of the protective wind cap; the atomizing wind transmission channel is between the inner wall of the atomizing wind pipe and the outer wall of the liquid pipe, and one end of the atomizing wind transmission channel is connected to the gas inlet of the atomizing nozzle; one end of the liquid pipe is connected to the liquid interface of the atomizing nozzle. The invention can effectively resist the influence of dust in the flue gas and prevent the pipeline blockage caused by the evaporation of the liquid in the high temperature environment during the transmission process.

Description

Technical Field

[0001] The invention belongs to the field of energy conservation and environmental protection, and relates to a urea solution spray gun, in particular to an L-shaped urea solution spray gun protected by an air curtain. Background Art

[0002] In the field of SCR flue gas denitrification, the technology of direct injection of urea solution into the flue to produce ammonia by pyrolysis is the most energy-saving method of producing ammonia from urea. The main principle is to use multiple spray guns arranged by grid method to spray equal amounts of urea solution into the flue gas at the original AIG (ammonia injection grid) position of the SCR inlet flue. Due to the high temperature and high dust flue gas environment, and the flue gas flows from bottom to top, the nozzle must be facing upward when spraying downstream. These restrictions cause many difficulties and conventional spray guns cannot be used. Since the flow rate of urea solution at each injection point is extremely small, the urea solution is easily heated and vaporized and dried during the process of being transmitted from the outside of the flue to the injection point in the flue, blocking the circulation pipeline; dust in the flue gas will accumulate near the nozzle, eventually leading to atomization injection failure; when spraying upward, it is necessary to prevent the ash mass above from falling and hitting the nozzle, and also to prevent the horizontal section of the transmission pipe from accumulating ash and submerging the nozzle. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide an L-shaped urea solution spray gun with wind curtain protection, which can effectively isolate dust in the flue gas and prevent the accumulation of dust near the nozzle through the wind curtain formed by the protective wind around the nozzle. The protective wind can also block the heat transfer from the external hot flue gas to the urea solution, and prevent the urea solution from being evaporated and blocked in the liquid pipeline during the transmission process in a high-temperature environment.

[0004] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] An air curtain protected L-shaped urea solution spray gun, comprising a protective air cap, an atomizing nozzle and an L-shaped transmission pipe connected to the atomizing nozzle;

[0006] The L-shaped transmission pipe includes a nozzle seat, a protective air pipe, an atomizing air pipe, a liquid pipe, a protective air channel, an atomizing air channel and a liquid channel; the nozzle seat includes a protective air channel, an atomizing air channel and a liquid channel which are concentrically arranged from the outside to the inside;

[0007] The protective air duct, atomizing air duct and liquid pipe are arranged concentrically from outside to inside;

[0008] The protective air cap and the atomizing nozzle are both arranged on the nozzle seat;

[0009] The inner wall of the protective air duct and the outer wall of the atomizing air duct are the protective air transmission channel, and one end of the protective air transmission channel is connected to the inner side of the protective air cap;

[0010] An atomizing air transmission channel is formed between the inner wall of the atomizing air duct and the outer wall of the liquid pipe, and one end of the atomizing air transmission channel is connected to the gas inlet of the atomizing nozzle;

[0011] One end of the liquid pipe is connected to the liquid interface of the atomizing nozzle.

[0012] A further improvement of the present invention is that the atomizing nozzle is connected to the nozzle seat via a thread; the protective air cap is connected to the nozzle seat via a thread; and the atomizing nozzle is located inside the protective air cap.

[0013] A further improvement of the present invention is that the outer wall surface of the protective hood is arc-shaped.

[0014] A further improvement of the present invention is that the atomizing nozzle is a two-fluid atomizing nozzle with a spray angle of 15°.

[0015] A further improvement of the present invention is that a liquid wall is provided between the liquid channel and the atomizing wind channel, an atomizing wind wall is provided between the atomizing wind channel and the protective wind channel, and a protective wind wall is provided outside the protective wind channel.

[0016] A further improvement of the present invention is that the atomizing wind wall is connected to the protective wind wall through four circumferentially equally divided protective wind bridges; the liquid wall is connected to the atomizing wind wall through four circumferentially equally divided atomizing wind bridges; the protective wind bridges and the atomizing wind bridges are circumferentially staggered at 45°.

[0017] A further improvement of the present invention is that the protective air duct includes a connected vertical section and a horizontal section; the end of the vertical section of the protective air duct is welded to the protective air wall of the nozzle seat, and the end of the horizontal section of the protective air duct is welded to the protective air joint; the end of the vertical section of the atomizing air duct is welded to the atomizing air wall of the nozzle seat; and the end of the vertical section of the liquid pipe is welded to the liquid wall of the nozzle seat.

[0018] A further improvement of the present invention is that a protective air interface is provided at the tail of the protective air duct, a dilution water interface and a urea solution interface are provided at the tail of the liquid pipe, and an atomizing air interface is provided at the tail of the atomizing air duct.

[0019] A further improvement of the present invention is that the other end of the protective wind transmission channel is connected to the protective wind interface; the other end of the atomizing wind transmission channel is connected to the atomizing wind interface; the other end of the liquid pipe is respectively connected to the dilution water interface and the urea solution interface.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention can effectively resist the influence of dust in the flue gas. In the flue gas flowing upward in the vertical flue at the SCR inlet, a blade-shaped dust accumulation of a certain height will be formed on the upper part of the horizontal section of the spray gun (the back of the airflow). The vertical section height of the L-shaped spray gun of the present invention is greater than the dust accumulation height, and the nozzle will not be submerged by the dust accumulation; the wind curtain protection technology is adopted to isolate the nozzle from the dust in the flue gas, and no dust accumulation will be formed at the nozzle during long-term operation. The present invention can prevent the liquid pipeline from being blocked. The present invention adopts a concentric set arrangement of protective wind, atomizing wind, and liquid to effectively block the heat transfer from the external high-temperature flue gas to the internal liquid pipeline.

[0022] Furthermore, the protective air bridge and the atomizing air bridge of the mist nozzle seat are staggered at 45° in the circumferential direction, which can effectively block the heat transfer from the external high-temperature flue gas to the internal liquid pipeline.

[0023] Furthermore, due to the constant pressure dilution water, as the flow rate of urea solution increases or decreases, the dilution water changes in a complementary manner, so that the liquid pipeline maintains a constant maximum flow rate. These measures can prevent the liquid from drying up during the transmission process and avoid blockage of the liquid pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the present invention.

[0025] Figure 2 For along Figure 1 Section view along line AA.

[0026] Among them, 1-protective wind cap; 2-atomizing nozzle; 3-nozzle seat; 4-vertical section; 5-protective wind duct; 6-horizontal section; 7-atomizing air duct; 8-protective wind joint; 9-protective wind sealing ring; 10-protective wind pressure screw; 11-atomizing air joint; 12-atomizing air pressure ring; 13-atomizing air sealing ring; 14-atomizing air pressure screw; 15-liquid pipe; 16-dilution water interface; 17-urea solution interface; 18-atomizing air interface; 19 protective wind interface; 20-atomizing air channel; 21-liquid channel; 22-protective wind channel; 23-protective wind bridge; 24-atomizing wind bridge; 25 protective wind wall; 26 liquid wall; 27-atomizing wind wall. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0028] See also Figure 1 and Figure 2 The wind curtain protection L-type urea solution spray gun of the present invention comprises a protective wind cap 1, an atomizing nozzle 2, an L-type transmission pipe, etc.; wherein,

[0029] The protective wind cap 1 is made of stainless steel, the outer wall is arc-shaped, and the inner wall shape matches the shape of the atomizing nozzle 2, forming a closed wind curtain composed of high-speed airflow at its outlet.

[0030] The atomizing nozzle 2 is a two-fluid atomizing nozzle with a spray angle of 15°;

[0031] The L-shaped transmission pipe includes a nozzle seat 3, a protective air duct 5, an atomizing air duct 7, a liquid pipe 15, a protective air joint 8, a protective air sealing ring 9, a protective air pressure screw 10, an atomizing air joint 11, an atomizing air pressure ring 12, an atomizing air sealing ring 13 and an atomizing air pressure screw 14, etc.; wherein, the nozzle seat 3 is provided with concentric protective air channels 22, atomizing air channels 20 and liquid channels 21 from the outside to the inside, and the three channels are isolated and closed by a protective air wall 25, an atomizing air wall 27 and a liquid wall 26; specifically, a liquid wall 26 is provided between the liquid channel 21 and the atomizing air channel 20, an atomizing air wall 27 is provided between the atomizing air channel 20 and the protective air channel 22, and a protective air wall 25 is provided on the outside of the protective air channel 22. The atomizing wind wall 27 is connected to the protective wind wall 25 through four circumferentially equally divided protective wind bridges 23; the liquid wall 26 is connected to the atomizing wind wall 27 through four circumferentially equally divided atomizing wind bridges 24; the protective wind bridges 23 and the atomizing wind bridges 24 are staggered at 45° circumferentially.

[0032] The protective air duct 5, the atomizing air duct 7, and the liquid pipe 15 are arranged concentrically from the outside to the inside; the protective air duct 5 includes a connected vertical section 4 and a horizontal section 6; the end of the vertical section 4 of the protective air duct 5 is welded to the protective air wall 25 of the nozzle seat 3, and the end of the horizontal section 6 of the protective air duct 5 is welded to the protective air joint 8; the end of the vertical section of the atomizing air duct 7 is welded to the atomizing air wall 27 of the nozzle seat 3; the end of the vertical section of the liquid pipe 15 is welded to the liquid wall 26 of the nozzle seat 3.

[0033] The atomizing nozzle 2 is connected to the nozzle seat 3 through a thread; the protective air hood 1 is connected to the nozzle seat 3 through a thread; and the atomizing nozzle 2 is located inside the protective air hood 1 .

[0034] A protective wind transmission channel is provided between the inner wall of the protective wind duct 5 and the outer wall of the atomizing wind duct 7 . One end of the protective wind transmission channel is connected to the protective wind interface 19 , and the other end is connected to the inner side of the protective wind cap 1 through the protective wind channel 22 of the nozzle seat 3 .

[0035] An atomizing air transmission channel is provided between the inner wall of the atomizing air duct 7 and the outer wall of the liquid pipe 15 . One end of the atomizing air transmission channel is connected to the atomizing air interface 18 , and the other end is connected to the gas inlet of the atomizing nozzle 2 through the atomizing air channel 20 of the nozzle holder 3 .

[0036] One end of the liquid pipe 15 is connected to the dilution water interface 16 and the urea solution interface 17 through a tee, and the other end is connected to the liquid interface of the atomizing nozzle 2 through a liquid channel 21 of the nozzle holder 3 .

[0037] The protective wind sealing ring 9 isolates the protective wind, the atomizing wind and the external atmosphere from each other; the atomizing wind sealing ring 13 isolates the atomizing wind from the external atmosphere.

[0038] The specific working process of the present invention is:

[0039] The spray gun nozzle of the present invention is placed at the injection point in the flue, and the tail protection air interface 19, atomization air interface 18, dilution water interface 16 and urea solution interface are outside the flue and connected to the main system pipeline. The protection air interface 19 continuously introduces a certain flow of air to form a wind curtain with a flow rate of not less than 21m / s at the outlet of the protection wind cap; the atomization air interface 18 introduces atomization air with a constant pressure; the dilution water interface 16 introduces deionized water with a constant pressure; and the urea solution interface 17 introduces urea solution with a required flow rate.

[0040] The present invention can effectively resist the influence of dust in the smoke and prevent pipeline blockage caused by evaporation of liquid in a high-temperature environment during transmission.

Claims

1. An air curtain protected L-type urea solution spray gun, characterized in that: It comprises a protective hood (1), an atomizing nozzle (2), and an L-shaped transmission pipe connected to the atomizing nozzle (2); The L-shaped transmission pipe comprises a nozzle seat (3), a protective air pipe (5), an atomizing air pipe (7), a liquid pipe (15), a protective air channel (22), an atomizing air channel (20) and a liquid channel (21); the nozzle seat (3) comprises a protective air channel (22), an atomizing air channel (20) and a liquid channel (21) which are arranged concentrically from the outside to the inside; The protective air duct (5) comprises a vertical section (4) and a horizontal section (6) connected to each other; The end of the vertical section (4) of the protective air duct (5) is welded to the protective air wall (25) of the nozzle seat (3), and the end of the horizontal section (6) of the protective air duct (5) is welded to the protective air joint (8); the end of the vertical section of the atomizing air duct (7) is welded to the atomizing air wall (27) of the nozzle seat (3); and the end of the vertical section of the liquid pipe (15) is welded to the liquid wall (26) of the nozzle seat (3); The protective air duct (5), the atomizing air duct (7) and the liquid pipe (15) are arranged concentrically from the outside to the inside; The protective air cap (1) and the atomizing nozzle (2) are both arranged on the nozzle seat (3); A protective wind transmission channel is provided between the inner wall of the protective wind duct (5) and the outer wall of the atomizing wind duct (7), and one end of the protective wind transmission channel is connected to the inner side of the protective wind cap (1); An atomizing air transmission channel is formed between the inner wall of the atomizing air pipe (7) and the outer wall of the liquid pipe (15), and one end of the atomizing air transmission channel is connected to the gas inlet of the atomizing nozzle (2); One end of the liquid pipe (15) is connected to the liquid interface of the atomizing nozzle (2); The atomizing wind wall (27) is connected to the protective wind wall (25) via four circumferentially equally spaced protective wind bridges (23); the liquid wall (26) is connected to the atomizing wind wall (27) via four circumferentially equally spaced atomizing wind bridges (24); the protective wind bridges (23) and the atomizing wind bridges (24) are circumferentially staggered at 45 degrees.

2. The air curtain protection L-type urea solution spray gun according to claim 1, characterized in that: The atomizing nozzle (2) is connected to the nozzle seat (3) via a thread; the protective air cap (1) is connected to the nozzle seat (3) via a thread; and the atomizing nozzle (2) is located inside the protective air cap (1).

3. The air curtain protection L-type urea solution spray gun according to claim 1, characterized in that: The outer wall surface of the protective hood (1) is arc-shaped.

4. The air curtain protection L-type urea solution spray gun according to claim 1, characterized in that: The atomizing nozzle (2) is a dual-fluid atomizing nozzle with a spray angle of 15°.

5. The air curtain protection L-type urea solution spray gun according to claim 1, characterized in that: A liquid wall (26) is provided between the liquid channel (21) and the atomizing air channel (20), an atomizing air wall (27) is provided between the atomizing air channel (20) and the protective air channel (22), and a protective air wall (25) is provided outside the protective air channel (22).

6. The air curtain protection L-type urea solution spray gun according to claim 1, characterized in that: A protective air interface (19) is provided at the rear end of the protective air duct (5), a dilution water interface (16) and a urea solution interface (17) are provided at the rear end of the liquid pipe (15), and an atomizing air interface (18) is provided at the rear end of the atomizing air duct (7).

7. The air curtain protection L-type urea solution spray gun according to claim 6, characterized in that: The other end of the protective wind transmission channel is connected to the protective wind interface (19); the other end of the atomizing wind transmission channel is connected to the atomizing wind interface (18); and the other end of the liquid pipe (15) is respectively connected to the dilution water interface (16) and the urea solution interface (17).

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