Nozzle structure capable of mixing liquid at nozzle

Abstract

The invention discloses a nozzle structure capable of mixing liquid at a nozzle in the field of wafer cleaning, the nozzle structure mainly comprises a pipeline fixing seat, an inner shell and an outer shell, the inner shell and the outer shell are coaxially connected to form a primary mixing chamber and a final mixing chamber surrounding the primary mixing chamber, and the top of the primary mixing chamber is provided with an exhaust hole and is communicated with the final mixing chamber; the primary mixing chamber is used for mixed reaction of concentrated sulfuric acid and hydrogen peroxide, and the final mixing chamber receives mixed liquid overflowing from the primary mixing chamber and communicates with an inner hole of the nozzle. According to the invention, active degassing of a mixed solution before entering the final mixing chamber can be realized through the design of high-position overflow and the exhaust hole, and the mixing and degassing processes of high-activity chemicals are delayed to be completed at the near end of the nozzle, so that the purity of the mixed solution is effectively improved, and the stability of jet flow is ensured.

Description

Technical Field

[0001] This invention relates to the field of wafer cleaning technology, and more specifically to a nozzle structure that can mix liquids at the nozzle. Background Technology

[0002] In the fields of integrated circuit manufacturing and semiconductor wafer cleaning, the reliability and safety of chemical mixing and delivery are paramount. Modern high-end wafer cleaning equipment must dynamically configure and mix a variety of highly reactive chemicals according to different process requirements to efficiently remove organic residues and metallic impurities from wafer surfaces.

[0003] Taking the high-temperature sulfuric acid cleaning process SPM (a mixture of concentrated sulfuric acid and hydrogen peroxide) as an example, this mixture has extremely strong oxidizing power and is a commonly used key cleaning solution in the industry.

[0004] Traditional chemical delivery and mixing methods generally employ offline mixing or premixing schemes: concentrated sulfuric acid and hydrogen peroxide are mixed in a preset ratio in a special mixing rod outside the machine, and then delivered to the nozzle at the end of the robotic arm through a long pipeline.

[0005] However, this traditional premixing method presents significant technical challenges: First, SPM solution is a highly active and corrosive solution. Prolonged residence of the mixed solution in long pipelines not only accelerates the aging and corrosion of pipeline materials but also poses potential safety hazards.

[0006] Secondly, the highly reactive SPM solution undergoes a continuous, weak decomposition reaction during transport, generating oxygen bubbles. These bubbles accumulate in the pipeline, causing flow fluctuations, uneven spraying, and potentially even air blockage at the nozzle, severely impacting cleaning effectiveness and wafer yield.

[0007] To address these issues, traditional systems require significant investment in pipeline maintenance, regular replacement, and complex bubble removal equipment, but the results are often less than ideal. Summary of the Invention

[0008] The purpose of this invention is to provide a nozzle structure that can mix liquids at the nozzle, in order to solve the problem of... To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution: A nozzle structure capable of mixing liquids at the nozzle, comprising: The pipeline fixing seat has a first liquid inlet hole, a second liquid inlet hole, and a vent hole that are connected vertically. The inner shell is located at the bottom of the pipeline fixing seat and has a primary mixing chamber formed therein. The primary mixing chamber is used to receive the first cleaning liquid and the second cleaning liquid introduced by the first liquid inlet and the second liquid inlet respectively. The exhaust port connects the primary mixing chamber to the upper side of the pipeline fixing seat. The outer shell is fixedly installed at the bottom of the pipeline fixing seat, and the outer shell is located on the outside of the inner shell in a coaxial state, forming a final mixing chamber between the outer shell and the inner shell; The nozzle is fixedly installed at the bottom center of the housing, and the inner hole of the nozzle connects the final mixing chamber with the outside of the housing. Several overflow holes are formed at the high position of the side wall of the inner shell. The overflow holes connect the primary mixing chamber and the final mixing chamber. The overflow holes are used to increase the residence time of the mixture in the primary mixing chamber, so as to promote the full discharge of the gas generated during the mixing process.

[0009] Furthermore, a first extension tube and a second extension tube are formed at the bottom of the pipeline fixing seat. The first extension tube and the second extension tube extend downward to the initial mixing chamber. The first extension tube is connected to the first liquid inlet hole, and the second extension tube is connected to the second liquid inlet hole. A flow-limiting orifice is formed inside the second extension tube. The upper end of the flow-limiting orifice is connected to the second liquid inlet, and the lower end is connected to the initial mixing chamber. The diameter of the flow-limiting orifice is smaller than that of the second liquid inlet. The flow-limiting orifice is used to introduce the second cleaning fluid into the initial mixing chamber at a controlled low flow rate. A gradually narrowing transition section is formed between the second liquid inlet and the flow-limiting orifice.

[0010] Furthermore, the lower end of the second extension tube is a closed end, and an inclined injection hole is formed on its side wall, which is inclined downward toward the inner wall of the primary mixing chamber. The upper end of the inclined injection hole is connected to the flow limiting hole. The inclined injection hole is used to allow the second cleaning fluid to be introduced tangentially along the inner wall of the primary mixing chamber, so as to avoid the direct impact of the fluid on the liquid pool in the primary mixing chamber.

[0011] Furthermore, a filter screen is embedded in the upper part of the inner side of the inner shell. The first extension tube and the second extension tube both penetrate downward through the bottom wall of the filter screen. Several air guide holes are formed on the bottom wall of the filter screen, which connect the upper and lower sides of itself. The filter screen is used to prevent the mixture from splashing violently during reaction or flow fluctuation. At the same time, the air guide holes guide the gas in the primary mixing chamber to the exhaust port in an organized manner.

[0012] Furthermore, a liquid outlet hole for connecting the nozzle inner hole is formed at the center of the bottom wall of the outer shell, and an annular groove is formed on the inner bottom wall of the outer shell in a coaxial manner around the liquid outlet hole. The annular groove is used to form a low-speed buffer area on the bottom wall of the final mixing chamber, so as to force the mixture to enter the liquid outlet hole at a high liquid level, thereby ensuring the stability of the injection flow rate and preventing air bubbles from being drawn into the nozzle inner hole.

[0013] Furthermore, there are several liquid outlet holes, all of which are circumferentially and evenly distributed about the inner hole axis of the nozzle. All liquid outlet holes extend downward and do not penetrate the bottom wall of the outer shell. An upwardly extending circular through hole is formed on the outer bottom wall of the outer shell. The diameter of the circular through hole is the same as the inner hole diameter of the nozzle. The outlines of all liquid outlet holes and the outlines of the circular through hole are partially overlapped in the axial projection of the inner hole of the nozzle to disperse and converge the mixed liquid.

[0014] Furthermore, an arm-shaped outer shell is fitted on the outside of the pipe fixing seat, and the pipe fixing seat extends into the inner side of the arm-shaped outer shell. A nozzle bracket is fixedly connected to the pipe fixing seat on the inner bottom wall of the arm-shaped outer shell. A fixing nut that is fitted onto the upper half of the pipe fixing seat is fixedly installed on the top of the nozzle bracket. A set screw that radially abuts against the side wall of the pipe fixing seat is screwed on the side wall of the fixing nut.

[0015] Furthermore, the arm-shaped outer shell is provided with a first liquid inlet pipe, a second liquid inlet pipe, and a vent pipe respectively connected to the first liquid inlet hole, the second liquid inlet hole, and the vent hole. The first liquid inlet pipe is wrapped with heat insulation cotton to control the temperature of the first cleaning liquid and prevent it from crystallizing or clogging.

[0016] Furthermore, a radially extending limiting flange is formed on the top of the inner shell, and the limiting flange is pressed against the top of the outer shell by screwing the pipe fixing seat and the top of the outer shell together.

[0017] Furthermore, the top of the limiting flange has several grooves evenly distributed circumferentially, and the upper outer wall of the filter screen has several blocks corresponding to the grooves.

[0018] The beneficial effects of this invention are: This invention integrates a primary mixing chamber and a final mixing chamber inside the nozzle. The primary mixing chamber is used for the main mixing reaction, and the high-level overflow and vent design enables active degassing of the mixture before it enters the final mixing chamber. Meanwhile, the final mixing chamber serves as a buffer and stabilizing area before the mixture is sprayed, effectively isolating flow rate and reaction fluctuations. This allows for stable mixing and degassing of highly reactive chemicals at the last moment before the solution contacts the wafer, significantly improving the purity of the solution and the stability of the cleaning flow rate. Attached Figure Description

[0019] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0020] Figure 1 This is a three-dimensional structural diagram of an embodiment of the present invention; Figure 2 This is an exploded three-dimensional structural diagram of an embodiment of the present invention; Figure 3 This is a planar sectional view of the nozzle structure according to an embodiment of the present invention; Figure 4This is an exploded three-dimensional structural diagram of the nozzle in an embodiment of the present invention; Figure 5 for Figure 2 Enlarged schematic diagram of the structure at point A in the diagram; Figure 6 This is a three-dimensional assembly diagram of the inner shell and the filter screen according to an embodiment of the present invention; Figure 7 This is a partial planar sectional view of an embodiment of the present invention; Figure 8 This is a three-dimensional structural diagram of the pipe fixing seat according to an embodiment of the present invention; Figure 9 This is a perspective sectional view of the nozzle in an embodiment of the present invention; Figure 10 for Figure 9 Enlarged schematic diagram of the structure at point B in the diagram; Figure 11 for Figure 9 Enlarged schematic diagram of the structure at point C; The labels in the diagram represent the following: 1-pipe mounting base; 1a-first inlet hole; 1b-second inlet hole; 1c-vent hole; 1d-first extension pipe; 1e-second extension pipe; 1f-flow limiting hole; 1g-gradient transition section; 1h-oblique injection hole; 2-inner shell; 2a-initial mixing chamber; 2b-overflow hole; 2c-limiting flange; 2d-groove; 3-outer shell; 3a-final mixing chamber; 3b-outlet hole; 3c-annular groove; 3d-circular through hole; 4-nozzle; 5-filter screen; 5a-vent hole; 5b-block; 6-arm-shaped outer shell; 6a-first inlet pipe; 6b-second inlet pipe; 6c-vent pipe; 7-nozzle bracket; 8-fixing nut; 9-set screw. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] To overcome the technical problems of traditional premixing methods, such as corrosion of pipelines, contamination, and uneven flow caused by air bubbles during long-distance pipeline transportation, this embodiment provides a nozzle structure that allows for instant mixing at the nozzle. This structure allows highly reactive chemicals to mix at the nozzle just before they are ejected, greatly shortening the residence time of the mixture and fundamentally solving the problems of corrosion and air bubble accumulation in long pipelines.

[0023] Specifically, refer to Figures 1 to 11As shown, a nozzle structure capable of mixing liquids at the nozzle includes: The pipeline fixing seat 1 has a first liquid inlet hole 1a, a second liquid inlet hole 1b and a vent hole 1c that are through the vertical direction. The inner shell 2 is located at the bottom of the pipeline fixing seat 1, and a primary mixing chamber 2a is formed therein. The primary mixing chamber 2a is used to receive the first cleaning liquid (e.g., concentrated sulfuric acid) and the second cleaning liquid (e.g., hydrogen peroxide) introduced by the first liquid inlet 1a and the second liquid inlet 1b above, respectively. The exhaust port 1c connects the primary mixing chamber 2a with the upper side of the pipeline fixing seat 1. The outer shell 3 is fixedly installed at the bottom of the pipeline fixing base 1, and is located coaxially outside the inner shell 2, forming a final mixing chamber 3a between the outer shell 3 and the inner shell 2. Nozzle 4 is fixedly installed at the bottom center of housing 3, and the inner hole of nozzle 4 connects the final mixing chamber 3a with the outer side of housing 3.

[0024] In this structure, the first and second cleaning solutions are initially mixed in the primary mixing chamber 2a. Upon contact, the two chemicals may react rapidly and generate gases (such as oxygen produced by SPM mixing). These gases accumulate at the top of the primary mixing chamber 2a and are discharged through the exhaust port 1c. To ensure sufficient gas separation, several overflow ports 2b are formed at the high position of the side wall of the inner shell 2, connecting the primary mixing chamber 2a and the final mixing chamber 3a.

[0025] This design requires the mixture in the primary mixing chamber 2a to reach the height of the overflow orifice 2b before flowing into the final mixing chamber 3a. Therefore, the overflow orifice 2b is designed to increase the residence time of the mixture in the primary mixing chamber 2a, promoting the full discharge of gases generated during mixing. The mixture flows into the final mixing chamber 3a for final mixing and is then ejected through the nozzle 4.

[0026] In the above structure, both cleaning solutions are introduced directly through the inlet port of the pipeline mounting base 1. However, when handling highly hazardous chemicals such as concentrated sulfuric acid and hydrogen peroxide, the mixing process is extremely dangerous and generates intense heat. If hydrogen peroxide (the second cleaning solution) is added too quickly, it may lead to a runaway reaction or even an explosion. Therefore, it is essential to ensure that the second cleaning solution is added in a very slow and controlled manner.

[0027] To achieve this precise and safe control, a first extension tube 1d and a second extension tube 1e can be formed at the bottom of the pipe fixing base 1. The first extension tube 1d and the second extension tube 1e extend downwards to the primary mixing chamber 2a. The first extension tube 1d connects to the first inlet port 1a, and the second extension tube 1e connects to the second inlet port 1b. Specifically, to achieve slow introduction of the second cleaning fluid, a flow-limiting orifice 1f is formed within the second extension tube 1e. The upper end of the flow-limiting orifice 1f connects to the second inlet port 1b, and the lower end connects to the primary mixing chamber 2a. The diameter of the flow-limiting orifice 1f (e.g., 1 mm) is smaller than the diameter of the second inlet port 1b (e.g., 4 mm). This flow-limiting orifice 1f is used to introduce the second cleaning fluid into the primary mixing chamber 2a at a controlled low flow rate (similar to dropwise addition).

[0028] In order to allow the fluid to smoothly transition from the second inlet hole 1b to the flow restrictor hole 1f, a gradually narrowing transition section 1g is formed between the second inlet hole 1b and the flow restrictor hole 1f.

[0029] Although the flow restrictor 1f controls the overall flow rate of the second cleaning fluid, if the fluid directly impacts the concentrated sulfuric acid pool below in a vertical manner, it will still produce a violent local reaction and splash at the impact point, and high-speed injection may also introduce air bubbles.

[0030] To address this issue, the lower end of the second extension tube 1e can be designed as a closed end. An oblique injection hole 1h is formed on its side wall, tilted downwards (e.g., at a 45-degree angle) toward the inner wall of the primary mixing chamber 2a, and the upper end of the oblique injection hole 1h is connected to the flow-limiting hole 1f.

[0031] This structure allows the second cleaning solution (hydrogen peroxide) to be introduced tangentially along the inner wall of the primary mixing chamber 2a. The liquid flows slowly into the liquid pool along the inner wall, achieving a smooth and non-impact mixing process. This ensures the stability of the reaction with concentrated sulfuric acid and avoids the generation of bubbles during the hydrogen peroxide introduction process.

[0032] During the SPM mixing reaction, oxygen is inevitably produced. When the flow rate fluctuates or the reaction is vigorous, the liquid in the primary mixing chamber 2a may splash violently. If these highly corrosive droplets splash into the vent 1c, they will not only corrode the upstream pipes and valves, but may also block the vent passage, causing pressure buildup in the chamber and posing a safety hazard.

[0033] To prevent splashing and ensure smooth venting, a filter screen 5 can be embedded in the upper inner half of the inner shell 2. The first extension tube 1d and the second extension tube 1e both extend downwards through the bottom wall of the filter screen 5. The filter screen 5 acts as a physical barrier to prevent violent splashing of the mixture during reaction or flow fluctuations. Simultaneously, several air guide holes 5a are formed on the bottom wall of the filter screen 5, connecting its upper and lower sides. These air guide holes 5a can systematically guide the gas in the initial mixing chamber 2a to the exhaust port 1c, while blocking liquid droplets.

[0034] After the mixture enters the final mixing chamber 3a through the overflow hole 2b, it is necessary to ensure that any remaining micro-air bubbles are completely removed before entering the nozzle 4; otherwise, the uniformity of the spray will be affected. To achieve efficient venting and ensure stable spraying, an outlet hole 3b for connecting to the inner hole of the nozzle 4 is formed at the center of the bottom wall of the housing 3. An annular groove 3c, coaxially surrounding the outlet hole 3b, is formed on the inner bottom wall of the housing 3. This structure has a dual venting mechanism: First, the annular groove 3c is used to form a low-speed buffer zone on the bottom wall of the final mixing chamber 3a. The flow rate of the mixed liquid in this zone is slowed down, which helps the micro bubbles to float. At the same time, the low-speed buffer zone can effectively suppress and eliminate fluid turbulence and eddies, so that the mixed liquid converges towards the outlet hole 3b in a stable and uniform flow state, thereby ensuring the stability of the jet flow rate. Secondly, the mixture must "cross" the inner edge of the annular groove 3c to enter the outlet 3b. During this process, the liquid's depth decreases significantly compared to the depth of the annular groove 3c. The time required for bubbles to rise and dissipate in this shallow liquid area is extremely short.

[0035] Therefore, the buffering effect of the annular groove 3c provides the first layer of venting, while the shallow liquid level area formed beyond the edge of the groove provides the second layer of accelerated venting. This process ensures that the air bubbles are fully removed before entering the liquid outlet 3b, thereby eliminating air resistance, ensuring the stability of the jet flow rate, and preventing air bubbles from being drawn into the inner hole of the nozzle 4.

[0036] In the above design, the liquid in the final mixing chamber 3a (which is under relatively high pressure due to the upstream supply pressure and its own head pressure) must converge and accelerate into the much smaller outlet orifice 3b in order to be ejected. If this confluence process is completed through only one centralized outlet orifice 3b, the fluid will accelerate sharply there. According to Bernoulli's principle, the surge in velocity will lead to a sharp drop in local static pressure. If this static pressure drops below the saturation pressure of dissolved gases in the liquid (such as O2 produced by the decomposition of SPM), the dissolved gases will precipitate instantaneously, generating a large number of new bubbles (i.e., cavitation), which will significantly limit the ejection effect.

[0037] To suppress bubble precipitation caused by a sudden pressure drop, this embodiment can have a plurality of liquid outlet holes 3b. All liquid outlet holes 3b are circumferentially and uniformly distributed about the inner bore axis of the nozzle 4. All liquid outlet holes 3b extend downward and do not penetrate the bottom wall of the outer casing 3. Correspondingly, an upwardly extending circular through hole 3d is formed on the outer bottom wall of the outer casing 3, and the diameter of the circular through hole 3d is the same as the inner bore diameter of the nozzle 4. The outlines of all liquid outlet holes 3b and the outlines of the circular through hole 3d are partially overlapped in the axial projection of the inner bore of the nozzle 4.

[0038] This "distributed confluence" structure is a sophisticated fluid geometry control scheme that disperses the total fluid flow into multiple outlet holes 3b, avoiding blockage and rapid acceleration of the fluid at a single inlet. By distributing the acceleration process across multiple channels, this design effectively prevents extreme local velocity peaks and corresponding static pressure drops at any point, ensuring that the fluid pressure is always maintained above the bubble precipitation threshold, thereby suppressing cavitation and guaranteeing stable jetting.

[0039] Furthermore, the nozzle 4 structure needs to be installed on the moving parts of the main equipment, such as the end effector of a robotic arm. During high-speed movement of the equipment, it is essential to ensure that the nozzle 4 structure is securely fixed to prevent loosening or displacement, which could affect the accuracy of the spray.

[0040] To ensure secure installation, an arm-shaped housing 6 can be fitted onto the outer side of the pipe mounting base 1. The arm-shaped housing 6 serves as a component connecting the nozzle mechanism to the main body of the device. The pipe mounting base 1 extends into the inner side of the arm-shaped housing 6. A nozzle bracket 7, which is fixedly connected to the pipe mounting base 1, is provided on the inner bottom wall of the arm-shaped housing 6. A fixing nut 8, which is fitted onto the upper half of the pipe mounting base 1, is fixedly installed on the top of the nozzle bracket 7. A set screw 9, which radially abuts against the side wall of the pipe mounting base 1, is screwed onto the side wall of the fixing nut 8. By locking the set screw 9, it is ensured that the nozzle 4 structure cannot move relative to the arm-shaped housing 6 during its movement.

[0041] To connect the nozzle 4 structure to the main piping of the equipment, a first inlet pipe 6a, a second inlet pipe 6b (e.g., both the first and second inlet pipes 6b are 1 / 4-inch PFA pipes) and an exhaust pipe 6c are respectively installed inside the arm-shaped housing 6, connecting the first inlet port 1a, the second inlet port 1b, and the exhaust port 1c. These pipes are connected to upstream chemical supply units (such as valves and pumps) and exhaust gas treatment systems (not shown in the figure). The opening and closing of the valves in each supply unit are controlled by a program, facilitating formula switching and dynamic adjustment of mixing ratios.

[0042] In some processes, temperature control of chemicals may be required. For this purpose, the first inlet pipe 6a may be equipped with insulation cotton to control the temperature of the first cleaning solution and prevent it from crystallizing or clogging.

[0043] In the assembly of the nozzle 4 structure, the inner shell 2, outer shell 3, and pipe mounting base 1 need to be reliably assembled and sealed to prevent leakage of highly corrosive liquids. To achieve a secure assembly and seal, a radially extending limiting flange 2c can be formed on the top of the inner shell 2. The limiting flange 2c is pressed against the top of the outer shell 3 by threaded tightening between the pipe mounting base 1 and the top of the outer shell 3. The limiting flange 2c provides reliable axial positioning and radial sealing.

[0044] If the aforementioned filter screen 5 is used, it needs to be stably fixed to the upper part of the inner shell 2 to prevent displacement during fluid impact or equipment movement. To achieve this fixation, the aforementioned limiting flange 2c can be used. Specifically, the top of the limiting flange 2c has several circumferentially evenly distributed grooves 2d. The upper outer wall of the filter screen 5 has several inserts 5b corresponding one-to-one with the grooves 2d. Through the cooperation of the inserts 5b with the grooves 2d, the filter screen 5 is securely installed on the top of the inner shell 2.

[0045] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its spirit and scope of protection, and such modifications or equivalent substitutions should also be considered as falling within the scope of protection of the embodiments of the present invention.

Claims

1. A nozzle structure capable of mixing liquids at the nozzle, characterized in that, include: The pipeline fixing seat (1) has a first liquid inlet hole (1a), a second liquid inlet hole (1b) and a vent hole (1c) that are through the vertical direction. The inner shell (2) is located at the bottom of the pipeline fixing seat (1) and has a primary mixing chamber (2a) formed therein. The primary mixing chamber (2a) is used to receive the first cleaning liquid and the second cleaning liquid introduced by the first liquid inlet (1a) and the second liquid inlet (1b) above, respectively. The exhaust port (1c) connects the primary mixing chamber (2a) with the upper side of the pipeline fixing seat (1). The outer shell (3) is fixedly disposed at the bottom of the pipeline fixing seat (1), and the outer shell (3) is located on the outside of the inner shell (2) in a coaxial state, and a final mixing chamber (3a) is formed between the outer shell (3) and the inner shell (2). The nozzle (4) is fixedly installed at the bottom center of the outer shell (3), and the inner hole of the nozzle (4) connects the final mixing chamber (3a) and the outer side of the outer shell (3); The inner shell (2) has several overflow holes (2b) formed at the high position of the side wall. The overflow holes (2b) connect the initial mixing chamber (2a) and the final mixing chamber (3a). The overflow holes (2b) are used to increase the residence time of the mixture in the initial mixing chamber (2a) so as to promote the full discharge of the gas generated during the mixing process.

2. The nozzle structure for mixing liquids at the nozzle according to claim 1, characterized in that, The bottom of the pipeline fixing seat (1) is formed with a first extension tube (1d) and a second extension tube (1e). The first extension tube (1d) and the second extension tube (1e) extend downward to the initial mixing chamber (2a). The first extension tube (1d) is connected to the first liquid inlet (1a), and the second extension tube (1e) is connected to the second liquid inlet (1b). A flow-limiting orifice (1f) is formed inside the second extension tube (1e). The upper end of the flow-limiting orifice (1f) is connected to the second liquid inlet (1b), and the lower end is connected to the primary mixing chamber (2a). The diameter of the flow-limiting orifice (1f) is smaller than the diameter of the second liquid inlet (1b). The flow-limiting orifice (1f) is used to introduce the second cleaning fluid into the primary mixing chamber (2a) at a controlled low flow rate. A tapered transition section (1g) is formed between the second liquid inlet (1b) and the flow-limiting orifice (1f).

3. The nozzle structure for mixing liquids at the nozzle according to claim 2, characterized in that, The lower end of the second extension tube (1e) is a closed end, and an oblique injection hole (1h) is formed on its side wall, which is inclined downward toward the inner wall of the primary mixing chamber (2a). The upper end of the oblique injection hole (1h) is connected to the flow limiting hole (1f). The oblique injection hole (1h) is used to allow the second cleaning liquid to be introduced tangentially along the inner wall of the primary mixing chamber (2a) to avoid the direct impact of the fluid on the liquid pool in the primary mixing chamber (2a).

4. A nozzle structure capable of mixing liquids at the nozzle according to claim 2, characterized in that, A filter screen (5) is embedded in the upper part of the inner shell (2). The first extension tube (1d) and the second extension tube (1e) both penetrate downward through the bottom wall of the filter screen (5). A number of air guide holes (5a) are formed on the bottom wall of the filter screen (5) that connect its upper and lower sides. The filter screen (5) is used to prevent the mixture from splashing violently during reaction or flow fluctuation. At the same time, the air guide holes (5a) systematically guide the gas in the initial mixing chamber (2a) to be discharged to the exhaust hole (1c).

5. The nozzle structure for mixing liquids at the nozzle according to claim 1, characterized in that, A liquid outlet hole (3b) for connecting the inner hole of the nozzle (4) is formed at the center of the bottom wall of the outer shell (3). An annular groove (3c) is formed on the inner bottom wall of the outer shell (3) and surrounds the liquid outlet hole (3b) in a coaxial state. The annular groove (3c) is used to form a low-speed buffer area on the bottom wall of the final mixing chamber (3a) to force the mixture to enter the liquid outlet hole (3b) at a high liquid level, thereby ensuring the stability of the injection flow rate and preventing air bubbles from being drawn into the inner hole of the nozzle (4).

6. A nozzle structure for mixing liquids at the nozzle according to claim 5, characterized in that, The number of liquid outlet holes (3b) is several. All the liquid outlet holes (3b) are evenly distributed circumferentially about the inner hole axis of the nozzle (4). All the liquid outlet holes (3b) extend downward and do not penetrate the bottom wall of the outer shell (3). An upwardly extending circular through hole (3d) is formed on the outer bottom wall of the outer shell (3). The diameter of the circular through hole (3d) is consistent with the inner hole diameter of the nozzle (4). The outlines of all the liquid outlet holes (3b) and the outlines of the circular through hole (3d) are partially overlapped in the axial projection of the inner hole of the nozzle (4) so ​​that the mixture is dispersed and converged.

7. The nozzle structure for mixing liquids at the nozzle according to claim 1, characterized in that, An arm-shaped outer shell (6) is fitted on the outside of the pipe fixing seat (1). The pipe fixing seat (1) extends into the inner side of the arm-shaped outer shell (6). A nozzle bracket (7) is fixedly connected to the pipe fixing seat (1) on the inner bottom wall of the arm-shaped outer shell (6). A fixing nut (8) is fixedly fitted on the top of the nozzle bracket (7) and connected to the upper half of the pipe fixing seat (1). A set screw (9) is screwed on the side wall of the fixing nut (8) to radially abut against the side wall of the pipe fixing seat (1).

8. A nozzle structure for mixing liquids at the nozzle according to claim 7, characterized in that, The arm-shaped outer shell (6) is provided with a first liquid inlet pipe (6a), a second liquid inlet pipe (6b), and an exhaust pipe (6c) respectively connected to the first liquid inlet hole (1a), the second liquid inlet hole (1b), and the exhaust hole (1c). The first liquid inlet pipe (6a) is wrapped with heat insulation cotton to control the temperature of the first cleaning liquid and prevent it from crystallizing or clogging.

9. A nozzle structure capable of mixing liquids at the nozzle according to claim 1, characterized in that, The top of the inner shell (2) has a radially extending limiting flange (2c). The limiting flange (2c) is pressed against the top of the outer shell (3) by the pipe fixing seat (1) and the top of the outer shell (3) by screwing together.

10. A nozzle structure capable of mixing liquids at the nozzle according to claim 4 or 9, characterized in that, The top of the limiting flange (2c) has a number of grooves (2d) evenly distributed in the circumferential direction, and the upper outer wall of the filter screen (5) has a number of blocks (5b) corresponding to the grooves (2d) one by one.

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