Urea homogenizing spraying device

Abstract

The utility model belongs to the technical field of urea pyrolysis ammonia preparation, and discloses a urea homogenizing spraying device which comprises an outer pipe and an inner pipe, a gap is formed between the inner pipe and the outer pipe, and one end of the outer pipe is provided with a first input end used for conveying a urea solution into the inner pipe and a second input end used for conveying compressed gas into the gap. The other end of the outer pipe is provided with an output end, the outer pipe is further provided with a corrugated section, and the corrugated section is located between the output end of the inner pipe and the output end of the outer pipe. The mode of the inner pipe and the outer pipe is adopted, negative pressure can be formed at the output end of the inner pipe through input of compressed air, so that a urea solution is sucked out and atomized for the first time, then the corrugated section is arranged on the outer pipe, the corrugated inner wall is formed in the outer pipe through the corrugated section, the airflow direction can be changed, the laminar flow state can be damaged, and high-strength turbulent flow can be formed; the vortex generated by the turbulent flow and the local high pressure difference can further tear the liquid drops atomized for the first time, so that the particle size of the liquid drops is smaller, and the atomization effect and uniformity are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of urea pyrolysis ammonia production, and specifically relates to a urea homogenization spraying device. BACKGROUND

[0002] Nitrogen oxide (NOx) is one of the main atmospheric pollutants. With the implementation of strict environmental protection standards, a flue gas denitration system has become one of the indispensable equipment in a thermal power plant. Selective catalyst reduction (SCR) has become the preferred technology for a power plant denitration project due to its high denitration efficiency, and has been more and more widely applied. There are three sources of reducing agent NH3 in the SCR technology: liquid ammonia, ammonia water and urea. Urea is selected as the reducing agent, has the characteristics of high safety, wide source, easy transportation and storage, and has been widely applied in the environmental protection field. There are two methods for urea ammonia production: pyrolysis and hydrolysis. The pyrolysis method has been rapidly promoted because of its mature and reliable process, and operation under normal pressure, without ammonia leakage and other reasons.

[0003] CN204369580U discloses a urea pyrolysis ammonia production system, which comprises a high-temperature dust collector, a temperature adjusting device, a pyrolysis furnace, a high-temperature fan arranged between the high-temperature dust collector and the pyrolysis furnace, an outlet of the temperature adjusting device connected to a flue gas pipe at the outlet of the high-temperature fan through a cold air pipe to mix cold air and high-temperature flue gas, the mixed cold air and flue gas connected to the inlet of the pyrolysis furnace through a pipeline, temperature measuring points arranged at the inlet and outlet of the pyrolysis furnace, and a urea nozzle arranged on the pyrolysis furnace.

[0004] The above technical scheme saves the air electric heater power consumption by using the high-temperature flue gas after dust removal to replace the existing air electric heater without reducing the operation safety of the denitration system and meeting the environmental protection requirements, eliminates the boiler air leakage caused by the injection of denitration ammonia gas, has excellent energy-saving effect, and achieves the best ammonia production effect.

[0005] However, in the urea pyrolysis ammonia production process, the nozzle atomization effect is poor, which may cause the sprayed urea solution to be unable to be homogenized and mixed with hot air to react to produce stable ammonia gas to reach the ammonia injection grid, thereby affecting the denitration efficiency, and the undecomposed urea solution is scaled in the pyrolysis furnace, causing difficult maintenance and unnecessary waste. Content of the utility model

[0006] The application aims at solving the above problems, and provides a urea homogenization injection device, which adopts an inner tube and an outer tube, input of compressed air can form negative pressure at an output end of the inner tube, so as to suck out urea solution and initially atomize, and then a corrugated section is arranged on the outer tube, the corrugated section forms a corrugated inner wall in the outer tube, which can change airflow direction, destroy laminar flow state, form high-intensity turbulent flow, and the vortex and local high pressure difference generated by the turbulent flow can further tear the liquid droplets initially atomized, so that the particle size is smaller, and the atomization effect and uniformity are improved.

[0007] To achieve the above object, the application provides the following technical scheme:

[0008] The urea homogenization injection device comprises an outer tube, an inner tube arranged in the outer tube, a gap arranged between the inner tube and the outer tube, a first input end arranged on one end of the outer tube for conveying urea solution into the inner tube, a second input end arranged on the outer tube for conveying compressed gas into the gap, an output end arranged on the other end of the outer tube, and a corrugated section arranged on the outer tube, wherein the corrugated section forms a corrugated inner wall in the outer tube, and the corrugated section is located between the output end of the inner tube and the output end of the outer tube.

[0009] Preferably, the inner tube comprises a tube body and a cone body connected to one end of the tube body, the cone body and the tube body are communicated, an end cover is further arranged on the outer tube, the cone body is connected to the end cover, the first input end is arranged on the end cover, and the second input end is arranged on the side surface of the end portion of the outer tube.

[0010] Preferably, a mesh plate is further arranged at the output end of the inner tube.

[0011] Preferably, the other end of the outer tube is closed, a plurality of output ports are arranged between the other end of the outer tube and the corrugated section, the output ports are arranged along the length direction of the outer tube, the plurality of output ports are arranged on the outer tube in a circumferential array, and the plurality of output ports are the output ends of the outer tube.

[0012] Preferably, a connecting piece is further arranged on the outer tube, and the connecting piece is used for fixing the outer tube on a kettle body arranged outside.

[0013] Preferably, the connecting piece is a flange, a through hole matched with the outer tube is arranged on the flange, a protruding connecting column is arranged on the end surface of the flange, the through hole extends through the connecting column, a bolt is arranged on one side of the connecting column, and the outer tube is matched with the through hole and the bolt to be connected to the flange in a detachable manner.

[0014] Preferably, a sealing piece is further arranged between the flange and the outer tube.

[0015] Compared with the prior art, the application has the following beneficial effects:

[0016] The application adopts the mode of inner and outer tubes, the input of compressed air can form negative pressure at the output end of the inner tube, so as to suck out and initially atomize the urea solution, and secondly, by setting a corrugated section on the outer tube, the corrugated section forms a corrugated inner wall in the outer tube, which can change the airflow direction, destroy the laminar flow state, form high-intensity turbulent flow, and the vortex and local high pressure difference generated by the turbulent flow can further tear the liquid droplets of the initial atomization, so that the particle size is smaller, and the atomization effect and uniformity are improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structural schematic view of the urea homogenization injection device of embodiment 1;

[0018] Figure 2 is Figure 1 A-A sectional view of

[0019] Wherein, each reference sign is as follows:

[0020] 1, outer tube; 2, inner tube; 3, gap; 11, first input end; 12, second input end; 13, corrugated section; 14, output port; 15, connecting piece; 16, end cover; 21, tube body; 22, cone; 23, mesh plate; 151, connecting column; 152, through hole; 153, bolt. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the application.

[0022] Embodiment 1

[0023] Reference Figure 1 and Figure 2 , a urea homogenization injection device, comprising an outer tube 1, an inner tube 2 arranged in the outer tube 1, a gap 3 arranged between the inner tube 2 and the outer tube 1, a first input end 11 arranged on one end of the outer tube 1 for conveying urea solution into the inner tube 2, a second input end 12 arranged on the other end of the outer tube 1 for conveying compressed gas into the gap 3, an output end arranged on the other end of the outer tube 1, and a corrugated section 13 arranged on the outer tube 1, the corrugated section 13 forming a corrugated inner wall in the outer tube 1, and the corrugated section 13 being located between the output end of the inner tube 2 and the output end of the outer tube 1.

[0024] It should be noted that the corrugated inner wall, i.e. the concave-convex structure, of the corrugated section 13 occupies part of the internal area of the tube body 21.

[0025] Under this design, the urea solution is input into the inner tube 2 from the first input end 11, and the compressed air is input into the gap 3 from the second input end 12. The delivered compressed air moves along the length direction of the inner tube 2 and passes through the output end of the inner tube 2, so that a negative pressure is formed at the output end of the inner tube 2, thereby forming an effect of sucking out the urea solution and mixing the urea solution with the compressed air for primary atomization. Specifically, when the compressed air contacts with the liquid, the kinetic energy of the airflow can scatter the liquid to form liquid droplets, and the high-speed airflow can fragment the liquid droplets to make them very small, thereby forming a mist state. After the primary atomized urea solution passes through the corrugated section 13, the concave structure can change the airflow direction, destroy the laminar flow state, and form high-intensity turbulent flow. The vortex and local high pressure difference generated by the turbulent flow can further tear the primary atomized liquid droplets to make them smaller, thereby improving the atomization effect and uniformity.

[0026] In this embodiment, the inner tube 2 includes a tube body 21 and a cone 22 connected to one end of the tube body 21. The cone 22 is in communication with the tube body 21. The outer tube 1 is further provided with an end cover 16. The cone 22 is connected to the end cover 16. The first input end 11 is located on the end cover 16, and the second input end 12 is located on the side surface of the end of the outer tube 1.

[0027] In the preferred embodiment, the inner diameter of the tube body 21 is smaller than the first input end 11. The cone 22 can better guide the urea into the tube body 21 and form an effect of gradually reducing the channel to increase the flow rate of the urea. In combination with the negative pressure effect of the compressed air at the output end of the tube body 21, the flow of the urea is more smooth.

[0028] In this embodiment, the output end of the inner tube 2 is further provided with a mesh plate 23. In actual use, the mesh plate 23 can play a cutting role. Specifically, when the urea solution passes through the mesh plate 23, it will be mechanically cut into multiple fine streams or tiny droplets, thereby forming a pre-atomization effect, greatly reducing the initial size of the droplets. When the smaller initial droplets are mixed with the compressed air later, they are more easily sheared and torn by the airflow, and the final atomized particles are finer and more uniform.

[0029] Preferably, the other end of the outer tube 1 is closed. A plurality of output ports 14 are arranged between the other end of the outer tube 1 and the corrugated section 13. The output ports 14 are arranged along the length direction of the outer tube 1 and arranged in a circumferential array on the outer tube 1. The plurality of output ports 14 are the output ends of the outer tube 1.

[0030] Specifically, because the diameter of the output port 14 is smaller than the inner diameter of the outer tube 1, the urea solution atomized inside the outer tube 1 can further improve the atomization effect when passing through the output port 14 with a smaller diameter. Moreover, the plurality of output ports 14 are arranged along the length direction of the outer tube 1 and arranged in a circumferential array on the outer tube 1, which can make the sprayed urea fully contact and react with the hot air in the external environment.

[0031] In the embodiment, the outer tube 1 is further provided with a connecting piece 15, which is used to fix the outer tube 1 on an outer pyrolysis kettle. Further, the connecting piece 15 is a flange, which is provided with a through hole 152 matched with the outer tube 1, and the end face of the flange is provided with a protruding connecting column 151, the through hole 152 extends through the connecting column 151, and the connecting column 151 is provided with a bolt 153 on one side, and the outer tube 1 is matched with the through hole 152 and the bolt 153 to be detachably connected with the flange.

[0032] In actual use, the outer pyrolysis kettle is provided with a connecting flange, which is the prior art in the field, and the operator only needs to connect the outer tube 1 on the outer pyrolysis kettle through the flange, and it should be noted that a sealing gasket is further provided between the flanges. In the embodiment, the outer tube 1 is detachable, which is convenient for the maintenance of the outer tube 1, therefore, preferably, a sealing member is further provided between the flange and the outer tube 1, preferably at the through hole 152, and more specifically, the cooperation between the outer tube 1 and the through hole 152 is not used to adapt the outer tube 1 with different outer diameters, therefore, the cooperation between the outer tube 1, the through hole 152 and the sealing member ensures the sealing between the outer tube 1 and the through hole 152, and the bolt 153 on one side of the connecting column 151 only has a reinforcing effect to avoid the sliding of the outer tube 1.

[0033] The above is only the preferred embodiment of the application, and it should be noted that for those skilled in the art, several improvements or modifications can be made without departing from the principles of the application, and these improvements or modifications should be considered as the protection scope of the application.

Claims

1. A urea homogenizing injection device comprising an outer tube, an inner tube disposed in said outer tube, a gap being provided between said inner tube and said outer tube, a first input for delivering a urea solution into the inner tube and a second input for delivering a compressed gas into said gap being provided on one end of said outer tube, an output being provided on the other end of said outer tube, characterized in that A corrugated section is further arranged on the outer tube, and the corrugated section forms a corrugated inner wall in the outer tube, and the corrugated section is located between the output end of the inner tube and the output end of the outer tube.

2. The urea homogenization injection device of claim 1, wherein, The inner tube comprises a tube body and a cone connected to one end of the tube body, and the cone is in communication with the tube body, and an end cover is further arranged on the outer tube, and the cone is connected to the end cover, and the first input end is located on the end cover, and the second input end is located on the side of the end of the outer tube.

3. The urea homogenization injection device of claim 1, wherein, A screen plate is further arranged at the output end of the inner tube.

4. The urea homogenization injection device of claim 1, wherein, The other end of the outer tube is closed, and a plurality of output ports are arranged between the other end of the outer tube and the corrugated section, and the output ports are arranged along the length direction of the outer tube, and the plurality of output ports are arranged in a circumferential array on the outer tube, and the plurality of output ports are the output ends of the outer tube.

5. The urea homogenization injection device of claim 1, wherein, A connecting piece is further arranged on the outer tube, and the connecting piece is used for fixing the outer tube on an externally arranged kettle body.

6. The urea homogenization injection device of claim 5, wherein, The connecting piece is a flange, and a through hole matched with the outer tube is arranged on the flange, and a protruding connecting column is arranged on the end face of the flange, and the through hole extends through the connecting column, and a bolt is arranged on one side of the connecting column, and the outer tube is matched with the through hole and the bolt to be connected with the flange in a detachable manner.

7. The urea homogenization injection device of claim 6, wherein, A sealing piece is further arranged between the flange and the outer tube.

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