Inkjet tracer device for dam crack detection
By designing inkjet tracking devices for ink reservoirs, underwater solenoid valves and dilution nozzles, the problems of high cost and limited depth in traditional dam crack detection are solved, and efficient and independent deep water detection capabilities are achieved, which can be used in high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality high-quality Work effectively under water pressure.
Patent Information
- Application Number
- CN201910400900.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2019-05-15
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2039-05-15
AI Technical Summary
Traditional dam crack detection methods require hiring divers, which are costly and have limited diving depth, and require heavy pipelines and coordinated communication with shore personnel.
A inkjet tracking device including an ink reservoir, an underwater solenoid valve and a dilution nozzle is designed. It is connected through a PU tube, and a high concentration tracer is diluted underwater by using a solenoid valve and a propeller to realize deep water detection. The device is independent And not affected by water depth and water pressure.
It realizes deep water detection capabilities with small size, light weight and easy operation, and can withstand 2.5MPa water pressure, reduces dependence on divers and the need for coordinated communication onshore, and improves detection efficiency.
Smart Images
Figure CN110118780B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of underwater inkjet devices, and in particular relates to an inkjet tracing device for dam crack detection. Background Art
[0002] After a period of use, the reservoir dam may develop cracks in the submerged part of the dam due to water scouring and its own weight, causing leakage. Severe leakage will have a serious impact on the safety of the dam. Regular detection and treatment of cracks is an essential measure.
[0003] The traditional way to detect leaks is for divers to dive into the water with pipes connected to pressurized equipment. Once a dangerous point is found, the valve can be opened and the pressurized equipment on the shore can be started to inject the tracer into the target point under high pressure. The waters near the target point will be dyed. If there is a crack, the pressure difference between the inside and outside of the crack will force the dyed water to flow into the crack, so that the crack location can be observed.
[0004] The disadvantages of traditional leak detection methods are as follows:
[0005] 1) Divers need to be hired, which is expensive and the diving depth of divers is limited to 30-50m.
[0006] 2) Divers need to carry the pipe down. If the distance is long, the pipe will also be long, which is troublesome to carry and heavy.
[0007] 3) It requires collaboration with shore personnel, and communication is difficult. Summary of the invention
[0008] In order to solve the problems in the background technology, the present invention provides an inkjet tracing device for dam crack detection, which can conveniently perform tracing detection underwater.
[0009] The technical solution adopted by the present invention is as follows:
[0010] The invention comprises an ink reservoir, an underwater electromagnetic valve and a dilution nozzle. The ink reservoir, the underwater electromagnetic valve and the dilution nozzle are connected in sequence through a PU tube, and the underwater electromagnetic valve is connected to an electric control device.
[0011] The ink reservoir includes an end cover, a cavity shell, a bottom plate, a piston, a spring, and a spring seat. The end cover is coaxially installed on the upper end surface of the cavity shell, the bottom plate is coaxially installed below the cavity shell, and the bottom plate and the cavity shell are connected through a plurality of copper columns.
[0012] A mounting hole is provided at the center of the end cover, which runs through from top to bottom. An annular boss is provided near the edge of the bottom surface of the end cover, and the outer side surface of the annular boss is sealed and connected with the inner side surface of the cavity shell; an outer flange is provided on the upper end surface of the cavity shell, and a piston is installed in the cavity shell to slide up and down along the inner side surface of the cavity shell; an inner flange is provided on the lower end surface of the cavity shell, and the stepped surface on the inner flange serves as a shoulder for supporting the piston; an inner cavity is provided at the center of the bottom surface of the piston, and a threaded countersunk hole is provided at the center of the bottom surface of the inner cavity of the piston, and the outer peripheral surface of the piston is sealed and connected with the inner side surface of the cavity shell by two grid rings; a tracer is contained in the cavity surrounded by the upper surface of the piston, the inner side surface of the cavity shell and the top surface of the end cover.
[0013] A flange is provided on the peripheral side surface of the lower end surface of the base plate, and a plurality of through holes are opened on the flange. A small hole is opened in the center of the base plate, and four circular holes of the same size and structure are closely and evenly distributed around the small hole. Two symmetrically arranged arc blocks are provided on both sides of the inner wall of each circular hole, and an arc groove is opened on the upper end surface of the arc block; a spring seat is installed inside each circular hole, and the upper end of the spring seat extends into the inner cavity opened in the center of the bottom surface of the piston. The spring seat is a hollow structure with an outer flange at the bottom, and an annular convex block is provided on the bottom surface of the outer flange. Two symmetrical arc lugs are provided on the outer peripheral surface of the outer flange, and the arc lugs are just embedded in the arc groove of the circular hole; the spring seat is used to support and fix the spring, one end of the spring is fixed to the bottom of the spring seat, and the other end is connected to the bottom surface of the piston. When the cavity is filled with tracer, the spring is in a compressed state.
[0014] The dilution nozzle includes a nozzle, an upper cover, a middle cover, a propeller machine and a lower cover. The upper cover, the middle cover and the lower cover are all hollow sleeve structures. The nozzle is connected to the upper end face of the upper cover by bolts, and the upper cover is coaxially fixedly connected to the lower cover through the middle cover; the nozzle is a bell-mouth structure, and the small opening at the upper end of the nozzle serves as a nozzle. An annular boss is provided at the lower end face of the nozzle near the edge, and the outer side surface of the annular boss is tightly sealed and connected to the inner side surface of the upper cover; a side hole is opened on both sides of the upper cover, and a circular hole for water flow to enter is opened at the bottom of the lower cover; the propeller machine body is located in the cavity surrounded by the upper cover and the middle cover, and the propeller machine body is installed on the inner side surface of the middle cover by three radially arranged fixing screws passing through the side wall of the middle cover, the propeller machine's propeller shaft faces downward, and the blades installed on the propeller shaft are located in the cavity of the lower cover, and the propeller machine wires connected to the propeller machine are connected to the electronic control device through the side hole opened on one side of the upper cover.
[0015] One end of the PU tube is connected to the mounting hole at the center of the end cover, and the other end of the PU tube extends through the underwater solenoid valve into the side hole opened on the other side of the dilution nozzle upper cover.
[0016] The tracer is bright red food coloring. The tracer flows into the dilution nozzle cavity through the PU tube. The rotation of the propeller drives the water flow in the cavity to stir so that the higher concentration tracer flowing into the cavity is mixed and diluted into a lower concentration tracer. Finally, the tracer is discharged from the nozzle of the nozzle.
[0017] The edge of the end cover is provided with a plurality of threaded holes, the flange of the cavity shell is provided with a plurality of through holes, the edge of the end cover and the flange of the cavity shell are fixedly connected by bolts, one end of each of the copper columns is installed to the through hole on the flange of the cavity shell, and the other end is installed to the through hole on the bottom plate flange.
[0018] An O-ring is installed between the outer side surface of the annular boss of the end cover and the inner side surface of the cavity shell, and an O-ring is installed between the edge of the end cover and the flange of the cavity shell; a rubber sealing ring is installed between the outer side surface of the annular boss of the nozzle and the inner side surface of the upper cover, and rubber sealing rings are installed on the contact surface between the upper cover and the middle cover, and on the contact surface between the upper cover and the middle cover.
[0019] The piston and the spring are made of rigid material or soft material, and the soft material is such as a compression bladder.
[0020] The nozzle is designed in a frustum form to facilitate the full mixing and dilution of high-concentration tracers and increase the outlet discharge flow rate.
[0021] The size of the circular hole at the bottom of the lower cover is similar to the size of the through hole of the nozzle, which prevents the rapid rotation of the propeller from causing a large-scale vortex effect on the external water flow and avoids interference with the overall control of the robot.
[0022] The installation method of each spring seat and the base plate is staggered installation. When the arc-shaped lugs on both sides of the bottom of the spring seat are aligned vertically with the position of the circular hole of the base plate where the arc block is not installed, an upward force is applied to the bottom of the spring seat so that the spring seat is inserted into the circular hole of the base plate, and the upper end of the spring presses upward against the bottom surface of the piston. Then, the spring seat is rotated 90 degrees so that the arc-shaped lugs of the spring seat and the arc-shaped grooves on the base plate are aligned vertically to achieve circumferential limiting. The spring seat is then driven to fall by relying on the downward pressure of the spring on the spring seat so that the arc-shaped lugs of the spring seat are embedded in the arc-shaped grooves of the base plate, so that the spring seat cannot rotate in the circular hole.
[0023] When copper columns of different lengths and springs of different sizes are used, the thrust generated by the spring on the bottom surface of the piston is different.
[0024] When the solenoid valve is opened, since the ink reservoir and the underwater solenoid valve are located at the same height underwater, the water pressures acting on the ink reservoir and the underwater solenoid valve are approximately equal. The tracer in the PU tube connecting the ink reservoir and the underwater solenoid valve is only subjected to the force of the spring when the water pressures at both ends are offset. Therefore, the present invention has nothing to do with water depth and water pressure during its specific implementation.
[0025] The present invention uses four small springs to replace a large spring, which is advantageous for realizing installation and removal by one person, and can ensure that the total pressure of the final spring is the sum of the pressures of the four small springs. When the interior is filled with a high-concentration tracer, installing the four springs in sequence can save more effort.
[0026] Beneficial effects of the present invention:
[0027] 1) The present invention has a small size, light weight, convenient operation and high efficiency. It only needs to carry a highly concentrated tracer into the water, and the water used for dilution is external water. Therefore, a small amount of concentrated tracer can still produce a large amount of diluted dyed water after being mixed and diluted with external water.
[0028] 2) The present invention has the ability to operate in deep water, can withstand an external water pressure of 2.5 MPa, and is not affected by the water depth, i.e., the external water pressure, when in use.
[0029] 3) The present invention is an independent device that can be carried on an underwater robot such as a manned submersible. It can realize a tracing means for detecting cracks in the dam body by only electrically controlling the on and off of the solenoid valve and the rotation and stop of the propeller. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 It is the overall connection diagram of the present invention.
[0031] Figure 2 It is a schematic structural diagram of the ink reservoir of the present invention.
[0032] Figure 3 It is a schematic structural diagram of the dilution nozzle of the present invention.
[0033] Figure 4 It is a structural schematic diagram of the spring seat of the present invention.
[0034] Figure 5 It is a structural schematic diagram of the base plate of the present invention.
[0035] In the figure: 1. ink reservoir; 2. underwater solenoid valve; 3. dilution nozzle; 4. end cover; 5. O-ring; 6. cavity shell; 7. copper column; 8. bottom plate; 9. piston; 10. Gly ring; 11. spring; 12. spring seat; 13. tracer; 14. nozzle; 15. rubber sealing ring; 16. upper cover; 17. PU tube; 18. propeller machine wire; 19. fixing screw; 20. middle cover; 21. propeller machine; 22. lower cover. DETAILED DESCRIPTION
[0036] The technical solution of the present invention is further specifically described below in conjunction with the accompanying drawings and embodiments.
[0037] like Figure 1 As shown, the present invention includes an ink reservoir 1, an underwater solenoid valve 2, and a dilution nozzle 3. The ink reservoir 1, the underwater solenoid valve 2, and the dilution nozzle 3 are connected in sequence through a PU tube 17. One end of the PU tube 17 is connected to a mounting hole at a center position of an end cover 4, and the other end of the PU tube 17 extends through the underwater solenoid valve 2 into a side hole opened on the other side of an upper cover 16 of the dilution nozzle 3.
[0038] like Figure 2 As shown, the ink reservoir 1 includes an end cover 4, a cavity shell 6, a bottom plate 8, a piston 9, a spring 11, and a spring seat 12. The end cover 4 is coaxially mounted on the upper end surface of the cavity shell 6, the bottom plate 8 is coaxially mounted below the cavity shell 6, and the bottom plate 8 is connected to the cavity shell 6 through a plurality of copper columns 7. A mounting hole is provided at the center of the end cover 4, and an annular boss is provided near the edge of the bottom surface of the end cover 4. The outer side surface of the annular boss is sealed and connected with the inner side surface of the cavity shell 6. An O-ring 5 is installed between the outer side surface of the annular boss of the end cover 4 and the inner side surface of the cavity shell 6, and a An O-ring 5 is provided; an outer flange is provided on the upper end surface of the cavity shell 6, and a piston 9 is installed in the cavity shell 6 to slide up and down along the inner side surface of the cavity shell 6; an inner flange is provided on the lower end surface of the cavity shell 6, and the step surface on the inner flange serves as a shoulder for supporting the piston 9 to prevent the piston 9 from falling out of the cavity; an inner cavity is provided at the center of the bottom surface of the piston 9, and a threaded countersunk hole is provided at the center of the bottom surface of the inner cavity of the piston 9 for manually sliding the piston 9; the outer peripheral surface of the piston 9 and the inner side surface of the cavity shell 6 are sealed and connected by two grid rings 10; a tracer 13 is installed in the cavity surrounded by the upper surface of the piston 9, the inner side surface of the cavity shell 6 and the top surface of the end cover 4.
[0039] like Figure 3 As shown, the dilution nozzle 3 includes a nozzle 14, an upper cover 16, a middle cover 20, a propeller 21 and a lower cover 22. The upper cover 16, the middle cover 20 and the lower cover 22 are all hollow sleeve structures. The nozzle 14 is connected to the upper end surface of the upper cover 16 by bolts, and the upper cover 16 is coaxially fixedly connected with the lower cover 22 through the middle cover 20; the nozzle 14 is a bell-mouth structure, the small opening at the upper end of the nozzle 14 serves as a nozzle, and an annular boss is provided near the edge of the lower end surface of the nozzle 14, and the outer side surface of the annular boss is sealed and connected with the inner side surface of the upper cover 16. ; There are side holes on both sides of the upper cover 16, and a round hole for water flow to enter is opened at the bottom of the lower cover 22; the body of the propeller machine 21 is located in the cavity surrounded by the upper cover 16 and the middle cover 20, and the body of the propeller machine 21 is installed on the inner side of the middle cover 20 through three fixing screws 19 radially arranged through the side wall of the middle cover 20, the propeller shaft of the propeller machine 21 faces downward, and the blades installed on the propeller shaft are located in the cavity of the lower cover 22, and the propeller machine wire connected to the propeller machine 21 passes through the side hole opened on one side of the upper cover 16 and is connected to the electric control device. The size of the round hole at the bottom of the lower cover 22 is similar to the size of the through hole of the nozzle, which prevents the rapid rotation of the propeller machine 21 from causing a large-scale vortex effect on the external water flow and avoids interference with the overall control of the robot. A rubber sealing ring 15 is installed between the outer side surface of the annular boss of the nozzle 14 and the inner side surface of the upper cover 16 . Rubber sealing rings 15 are installed on the contact surface between the upper cover 16 and the middle cover 20 and the contact surface between the upper cover 16 and the middle cover 20 .
[0040] like Figure 4As shown, the spring seat 12 is a hollow structure with a flange at the bottom, an annular protrusion is provided on the bottom surface of the flange, and two symmetrical arc-shaped flanges are provided on the outer peripheral surface of the flange, and the arc-shaped flanges are just embedded in the arc-shaped groove of the circular hole.
[0041] like Figure 5 As shown, a flange is provided on the side surface of the lower end surface of the bottom plate 8, and a plurality of through holes are opened on the flange. A small hole is opened at the center of the bottom plate 8, and four circular holes of the same size and structure are closely and evenly distributed around the small hole. Two symmetrically arranged arc blocks are provided on both sides of the inner wall of each circular hole, and an arc groove is opened on the upper end surface of the arc block; Specific embodiment:
[0043] The steps for installing the ink reservoir 1 and storing the tracer 13 on the shore are as follows: insert the piston 9 into the bottom of the chamber shell 6, fix the end cover 4 and the chamber shell 6 with bolts, and then fix the bottom plate 8 to the bottom of the chamber shell 6 with a copper column 7, and then inject the tracer 13 into the chamber shell 6 with a needle tube. After filling, the PU tube is sealed and connected to the mounting hole of the end cover 4 through a quick-tighten joint, and the other end of the PU tube is connected to one end of the solenoid valve 2. The spring 11 and the spring seat 12 are pressed through the hole of the bottom plate 8 in turn and rotated 90 degrees. The spring seat 12 and the bottom plate 8 are fixed circumferentially, and the spring pressure is used to lock the axial direction. When the tracer 13 is used up, take out the four springs 11 and the spring seat 12 in turn, extend one end of the bolt into the small hole in the center of the bottom plate 8 and install it to the threaded countersunk hole on the bottom surface of the piston 9, and drive the piston 9 to slide to the bottom by pulling the bolt downward, and then re-inject the tracer 13 into the mounting hole of the end cover 4 without dismantling the entire device and reinstalling it.
[0044] The PU tube 17 connected to the other end of the solenoid valve 2 is connected to the side hole opened on the side of the upper cover 16 of the dilution nozzle 3.
[0045] The whole device is carried on a manned submersible and dived underwater to start working. When the staff on shore finds the dangerous point of the dam, the underwater solenoid valve 2 is opened by the electronic control device. After 1 second, the underwater solenoid valve 2 is immediately closed to allow a small amount of high-concentration tracer 13 to flow into the dilution nozzle 3. The propeller 21 is turned on to rotate it. After a small amount of high-concentration tracer 13 is fully mixed with water, a large amount of diluted tracer 13 is discharged from the nozzle 14, and then the propeller 21 is closed.
Claims
1. An inkjet tracer device for dam crack detection, characterized in that: It comprises an ink reservoir (1), an underwater electromagnetic valve (2) and a dilution nozzle (3), wherein the ink reservoir (1), the underwater electromagnetic valve (2) and the dilution nozzle (3) are connected in sequence through a PU tube (17), and the underwater electromagnetic valve (2) is connected to an electric control device; The ink reservoir (1) comprises an end cover (4), a cavity shell (6), a bottom plate (8), a piston (9), a spring (11), and a spring seat (12); the end cover (4) is coaxially mounted on the upper end surface of the cavity shell (6); the bottom plate (8) is coaxially mounted below the cavity shell (6), and the bottom plate (8) and the cavity shell (6) are connected via a plurality of copper columns (7); a mounting hole is provided at the center of the end cover (4) and runs through the end and the end; an annular boss is provided near the edge of the bottom surface of the end cover (4); and the outer side surface of the annular boss is provided with a The cavity shell (6) is tightly and sealedly connected to the inner side surface of the cavity shell (6); the upper end surface of the cavity shell (6) is provided with an outer flange, a piston (9) is installed in the cavity shell (6) and slides up and down along the inner side surface of the cavity shell (6); the lower end surface of the cavity shell (6) is provided with an inner flange, and the stepped surface on the inner flange serves as a shoulder for supporting the piston (9); an inner cavity is provided at the center of the bottom surface of the piston (9), and a threaded countersunk hole is provided at the center of the bottom surface of the inner cavity of the piston (9); two grid rings ( 10) sealed connection; a tracer (13) is contained in a cavity surrounded by the upper surface of the piston (9), the inner side surface of the chamber shell (6) and the top surface of the end cover (4); a flange is provided on the side surface of the lower end surface of the bottom plate (8), and a plurality of through holes are opened on the flange; a small hole is opened at the center of the bottom plate (8), and four circular holes of the same size and structure are closely and evenly distributed around the small hole; two symmetrically arranged arc blocks are provided on both sides of the inner wall of each circular hole, and an arc groove is opened on the upper end surface of the arc block; each circular hole is installed inside A spring seat (12) is provided. The spring seat (12) is a hollow structure with an outer flange at the bottom. An annular convex block is provided on the bottom surface of the outer flange. Two symmetrical arc-shaped lugs are provided on the outer peripheral surface of the outer flange. The arc-shaped lugs are just embedded in the arc-shaped groove of the circular hole. The spring seat (12) is used to support and fix the spring (11). One end of the spring (11) is fixed to the bottom of the spring seat (12), and the other end is connected to the bottom surface of the piston. When the cavity is filled with a tracer (13), the spring (11) is in a compressed state. The dilution nozzle (3) comprises a nozzle (14), an upper cover (16), a middle cover (20), a propeller (21) and a lower cover (22); the upper cover (16), the middle cover (20) and the lower cover (22) are all hollow sleeve structures; the nozzle (14) is connected to the upper end surface of the upper cover (16) by bolts; the upper cover (16) is coaxially fixedly connected with the lower cover (22) through the middle cover (20); the nozzle (14) is a bell-mouth structure; the small opening at the upper end of the nozzle (14) serves as a nozzle; an annular boss is provided near the edge of the lower end surface of the nozzle (14); the outer side surface of the annular boss is closely connected to the inner side surface of the upper cover (16) in a sealing manner; both sides of the upper cover (16) are provided with a side hole; the bottom of the lower cover (22) is provided with a hole for water to enter; The propeller machine (21) is located in a cavity surrounded by the upper cover (16) and the middle cover (20). The propeller machine (21) is mounted on the inner side of the middle cover (20) by means of three fixing screws (19) radially arranged through the side wall of the middle cover (20). The propeller shaft of the propeller machine (21) faces downward, and the propeller blades mounted on the propeller shaft are located in the cavity of the lower cover (22). The propeller machine wire connected to the propeller machine (21) passes through a side hole opened on one side of the upper cover (16) and is connected to the electric control device. One end of the PU tube (17) is connected to the mounting hole at the center of the end cover (4), and the other end of the PU tube (17) extends through the underwater solenoid valve (2) into the side hole opened on the other side of the upper cover (16) of the dilution nozzle (3).
2. The inkjet tracer device for dam crack detection according to claim 1, characterized in that: The tracer (13) is a bright red food coloring agent. The tracer (13) flows into the cavity of the dilution nozzle (3) through the PU tube (17). The propeller (21) rotates to drive the water flow in the cavity to stir, so that the tracer (13) with a higher concentration flowing into the cavity is mixed and diluted into a tracer (13) with a lower concentration. Finally, the tracer (13) is discharged from the nozzle of the nozzle (14).
3. The inkjet tracer device for dam crack detection according to claim 1, characterized in that: The edge of the end cover (4) is provided with a plurality of threaded holes, the flange of the cavity shell (6) is provided with a plurality of through holes, the edge of the end cover (4) and the flange of the cavity shell (6) are fixedly connected by bolts, one end of each of the copper columns (7) is mounted to a through hole on the flange of the cavity shell (6), and the other end is mounted to a through hole on the flange of the bottom plate (8).
4. The inkjet tracer device for dam crack detection according to claim 1, characterized in that: An O-type sealing ring (5) is installed between the outer side surface of the annular boss of the end cover (4) and the inner side surface of the chamber shell (6), and an O-type sealing ring (5) is installed between the edge of the end cover (4) and the flange of the chamber shell (6); a rubber sealing ring (15) is installed between the outer side surface of the annular boss of the nozzle (14) and the inner side surface of the upper cover (16), and the contact surface between the upper cover (16) and the middle cover (20) and the contact surface between the upper cover (16) and the middle cover (20) are both installed with rubber sealing rings (15).
5. The inkjet tracer device for dam crack detection according to claim 1, characterized in that: The installation method of each spring seat (12) and the base plate (8) is offset installation. When the arc-shaped lugs on both sides of the bottom of the spring seat (12) are aligned with the position of the circular hole of the base plate (8) where the arc block is not installed, an upward force is applied to the bottom of the spring seat (12) so that the spring seat (12) is inserted into the circular hole of the base plate (8). The upper end of the spring (11) presses upward against the bottom surface of the piston (9). Then, the spring seat (12) is rotated 90 degrees so that the arc-shaped lugs of the spring seat (12) are aligned with the arc grooves on the base plate (8) to achieve circumferential limiting. Then, the spring seat (12) is driven to fall by the downward pressure of the spring (11) on the spring seat (12) so that the arc-shaped lugs of the spring seat (12) are embedded in the arc grooves of the base plate (8), so that the spring seat (12) cannot rotate in the circular hole.
6. The inkjet tracer device for dam crack detection according to claim 1, characterized in that: The nozzle (14) is designed in a frustum form to facilitate the full mixing and dilution of the tracer (13) and increase the outlet discharge flow rate.
7. The inkjet tracer device for dam crack detection according to claim 1, characterized in that: The size of the circular hole at the bottom of the lower cover (22) is similar to the size of the through hole of the nozzle, so as to prevent the propeller (21) from rotating rapidly and causing a large-scale vortex effect on the external water flow.
8. The inkjet tracer device for dam crack detection according to claim 1, characterized in that: The piston (9) and the spring (11) are made of rigid material or soft material.