A titration device for detecting the chloride ion content in concrete and its titration method

Abstract

The present invention belongs to the technical field of chloride ion content detection, and discloses a titration device and a titration method for detecting the chloride ion content in concrete, including a pretreatment tank. The bottom end of the pretreatment tank is fixedly communicated with a mixing tank. The top end of the pretreatment tank is fixedly installed with a frame. The bottom end of the outer side of the mixing tank is fixedly installed with a base. One side of the bottom end of the mixing tank is fixedly communicated with a drain valve. One side of the mixing tank near the top end is fixedly communicated with a titration head. By providing an electric push rod, a grinding disc, a grinding groove and a filtering groove at the top end of the mixing tank, the present invention realizes automatic grinding and filtering before titration through their mutual cooperation, and grinding and filtering can be carried out simultaneously with mixing and stirring, so that only by pouring in a concrete sample and a nitric acid solution, a standard solution can be obtained, without the need for external devices for assistance and the transportation of the solution, effectively avoiding the pollution of the solution, simplifying the operation steps and improving the test accuracy.

Description

Technical Field

[0001] The present invention belongs to the technical field of chloride ion content detection, and specifically relates to a titration device and a titration method for detecting the chloride ion content in concrete. Background Art

[0002] The detection of chloride ion content in concrete is an important step in evaluating the durability of concrete and the risk of steel bar corrosion. Chloride ions mainly come from cement raw materials, sand, mixing water, and admixtures, etc. When the chloride ion content exceeds the standard, it will accelerate the corrosion of steel bars and reduce the chemical resistance, abrasion resistance, and strength of concrete, thus affecting the durability of concrete.

[0003] Therefore, it is necessary to evaluate the chloride ion content in concrete and determine whether it exceeds the standard. In the evaluation process, the chemical titration method is generally used to evaluate the chloride ion content. Conventional chemical titration devices mainly consist of a burette, a mixing tank, and a stirrer. After grinding a concrete sample into powder and filtering it, it is mixed with a nitric acid solution to obtain a standard solution. Then, a potassium chromate indicator is titrated into the standard solution through the burette, and at the same time, the stirrer is turned on until the color of the solution changes significantly, which is the titration end point. According to the volume and concentration of the silver nitrate standard solution consumed in the titration, as well as the volume and weight of the solution to be measured, the chloride ion content in the concrete is calculated. This titration method requires the treatment of the standard solution and needs to be converted between multiple devices during the whole process. There is a risk of contamination of the standard solution, which affects the measurement accuracy.

[0004] At the same time, during the titration process, it is necessary to continuously stir the standard solution. However, in the current titration device during the mixing process, the stirrer part is fixed inside the mixing tank for a long time and can only mix one part of the mixed solution, and cannot perform a variable-range mixing process for the solution, resulting in a low mixing efficiency and urgently needing improvement. Summary of the Invention

[0005] The purpose of the present invention is to provide a titration device and a titration method for detecting the chloride ion content in concrete, so as to solve the problems proposed in the above background art.

[0006] To achieve the above object, the present invention provides the following technical solution: A titration device for detecting the chloride ion content in concrete, comprising a pretreatment tank, the bottom end of the pretreatment tank is fixedly communicated with a mixing tank, the top end of the pretreatment tank is fixedly installed with a frame, the bottom end of the outer side of the mixing tank is fixedly installed with a base, one side of the bottom end of the mixing tank is fixedly communicated with a drain valve, one side of the mixing tank near the top end is fixedly communicated with a titration head, one end of the outer side of the pretreatment tank is fixedly installed with a burette through a locking frame, the top end of the burette is fixedly communicated with a preparation pipe, the bottom end of the burette is fixedly communicated with a bent pipe, and the bent pipe is communicated with the titration head, the top end of the frame is fixedly installed with a motor, the output shaft of the motor is fixedly installed with an electric push rod located below the frame, the bottom end of the output shaft of the electric push rod is fixedly installed with a grinding disc, the middle of the bottom end of the grinding disc is fixedly installed with an extension shaft, the bottom end of the extension shaft is fixedly connected with an extension rod, the bottom end of the extension rod penetrates through the bottom end of the pretreatment tank and is fixedly connected with a mixing component located inside the mixing tank, and the mixing component rotates relative to the mixing tank.

[0007] Before the titration test, first inject an appropriate volume of nitric acid solution into the mixing tank, and inject the concrete sample into the pretreatment tank. At this time, the concrete enters the inside of the grinding groove, and a potassium chromate indicator is configured in the preparation pipe as needed for use.

[0008] As a further technical solution of the present invention, a grinding groove is opened at the top end of the pretreatment tank on the outer side of the grinding disc, a filtering groove is opened at the bottom end of the pretreatment tank on the outer side of the extension rod, and the extension shaft is movably sleeved between the bottom end of the grinding groove.

[0009] As a further technical solution of the present invention, a filter screen is fixedly installed at the bottom end of the pretreatment tank directly below the filtering groove, and a cleaning brush is fixedly installed at the top end of the outer side of the extension rod inside the filtering groove.

[0010] Before the titration test of the chloride ion content in concrete, at this time, the concrete sample can enter the inside of the grinding groove. At this time, according to the size of the concrete sample, the length of the electric push rod can be adjusted to change the gap between the bottom end of the grinding disc and the grinding groove. By starting the motor, the electric push rod rotates accordingly and drives the grinding disc at the bottom end to rotate. At this time, the grinding disc can grind the concrete inside the grinding groove, and the ground particles then enter the inside of the filtering groove, and after being filtered by the filter screen, enter the inside of the mixing tank and are mixed with the nitric acid solution inside to obtain a standard solution.

[0011] By arranging an electric push rod, a grinding disc, a grinding groove and a filtering groove at the top of the mixing tank, and using their mutual cooperation to achieve automatic grinding and filtering before titration, and the grinding and filtering can be carried out simultaneously with the mixing and stirring, so that only the concrete sample and the nitric acid solution need to be poured to obtain the standard solution, without the assistance of external devices and the transportation of the solution, which can effectively avoid the pollution of the solution, simplify the operation steps and improve the test accuracy.

[0012] As a further technical solution of the present invention, when the electric push rod is at the maximum stretching length, the bottom end of the grinding disc is close to the bottom end of the grinding groove, and the bottom end of the cleaning brush is in contact with the top end of the filter net.

[0013] When the particles of the concrete fragments are too large and block the filter net, at this time, the electric push rod can be turned on and driven to extend, and at this time, the grinding disc will descend accordingly, reducing the gap between it and the grinding groove. At the same time, the cleaning brush will descend until it is in contact with the top end of the filter net. At this time, the rotation of the grinding disc can drive the cleaning brush to rotate circumferentially relative to the filter net to automatically clean the surface of the filter net, completing the automatic cleaning process.

[0014] As a further technical solution of the present invention, the mixing assembly includes a mounting plate, the top end of the mounting plate is connected to the bottom end of the extension rod, the mixing assembly further includes a fixed sleeve located below the mounting plate, the fixed sleeve is movably connected to the middle of the bottom end of the mixing tank, and the fixed sleeve rotates relative to the mixing tank.

[0015] As a further technical solution of the present invention, the bottom end of the mounting plate is fixedly connected with a piston rod, the bottom end of the piston rod penetrates through the top end of the fixed sleeve and is fixedly connected with a piston plate located inside the fixed sleeve, and the piston plate moves up and down relative to the fixed sleeve.

[0016] As a further technical solution of the present invention, the outer side of the piston rod is movably sleeved with a limiting spring located inside the fixed sleeve, the upper and lower ends of the limiting spring are respectively connected to the top end of the inner cavity of the fixed sleeve and the top end of the piston plate, and fixed guide rails are fixedly installed at equal angles at a position close to the bottom end of the outer side of the fixed sleeve.

[0017] As a further technical solution of the present invention, first fixing seats are fixedly installed at equal angles at the bottom end of the mounting plate, the ends of the first fixing seats far away from the mounting plate are all movably connected with mixing rods through rotating shafts, the ends of the mixing rods far away from the first fixing seats are all movably connected with second fixing seats through rotating shafts, the bottom ends of the second fixing seats are all fixedly connected with guide blocks, and the guide blocks are movably clamped with the fixed guide rails.

[0018] When the grinding disc rotates, it can synchronously drive the extension rod to rotate. At this time, the piston rod and the fixed sleeve at the bottom end rotate accordingly, and drive the mixing rod on the outer side to rotate circumferentially. At this time, the mixing rod can mix and stir the standard solution located inside the mixing tank and the solution titrated in, and complete sufficient mixing;

[0019] Moreover, when the particles of the concrete sample decrease, due to the descent of the extension rod, the piston rod and the mounting plate can be driven to descend at this time. At this time, the mixing rod is subjected to a force, which drives the mixing rod to deflect towards the outer side, and drives the guide block to displace towards the outer side of the fixed guide rail. At this time, the mixing rod displaces towards the inner side of the mixing tank, and the mixing range increases accordingly. On the contrary, when the electric push rod shortens, the mixing range decreases.

[0020] By utilizing the previous grinding process, it can realize the mixing and stirring process while grinding. At the same time, when the concrete debris decreases and the filter screen is cleaned, due to the descent of the extension rod, the mixing range of the mixing component increases accordingly, realizing the variability of the mixing range. And the entire process only needs to control the length of the electric push rod, which effectively improves the mixing quality, improves the corresponding mixing efficiency, and finally improves the accuracy of the titration test.

[0021] A titration method for a titration device for detecting the chloride ion content in concrete includes the following steps:

[0022] S1: First, nitric acid solution can be poured into the mixing tank, and the concrete sample can be injected into the grinding groove through the top of the pretreatment tank. Then, the motor is turned on to drive the electric push rod to rotate. At this time, the grinding disc rotates accordingly, and grinds the concrete located inside the grinding groove;

[0023] S2: The ground concrete is filtered by the filter screen and enters the mixing tank for temporary storage. At the same time, the electric push rod can be turned on to drive the grinding disc to displace downward. At this time, the extension shaft and the extension rod move downward accordingly until the cleaning brush contacts the filter screen, and the surface of the filter screen is cleaned by the circumferential rotation of the cleaning brush;

[0024] S3: The crushed concrete enters the mixing tank and mixes with the nitric acid solution to obtain a standard solution. At this time, the solution can be prepared through the preparation pipe, potassium chromate indicator is added into the preparation pipe, and is titrated into the mixing tank through the burette, the elbow pipe and the titration head to complete the titration process;

[0025] S4: At the same time, the rotation of the electric push rod can synchronously realize the rotation of the extension rod. At this time, the mixing rod rotates circumferentially first, completing the mixing process of the solution inside the mixing tank. And when the extension rod moves downward, the mixing rod can rotate towards the outer side at this time, and the mixing range increases accordingly, completing the mixing process of the solution in a large range;

[0026] S5: When the color of the solution changes significantly, it is the titration end point. Based on the volume and concentration of the silver nitrate standard solution consumed in the titration, as well as the volume and weight of the solution to be tested, calculate the chloride ion content in the concrete.

[0027] The beneficial effects of the present invention are as follows:

[0028] 1. By providing an electric push rod, a grinding disc, a grinding groove and a filtering groove at the top of the mixing tank, the present invention realizes automatic grinding and filtering before titration through their mutual cooperation. Moreover, grinding and filtering can be carried out simultaneously with mixing and stirring, so that a standard solution can be obtained only by pouring in the concrete sample and nitric acid solution, without the need for external devices for assistance and solution transfer, effectively avoiding solution contamination, simplifying the operation steps and improving the test accuracy.

[0029] 2. By utilizing the previous grinding process, the present invention realizes the mixing and stirring process while grinding. At the same time, when the concrete fragments are reduced and the filter net is cleaned, due to the descent of the extension rod, the mixing range of the mixing component increases accordingly, realizing variable mixing range. And the whole process only needs to control the length of the electric push rod, effectively improving the mixing quality, corresponding mixing efficiency and finally the titration test accuracy. Description of the Drawings

[0030] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0031] Figure 2 is a cross-sectional schematic diagram of the internal structure of the burette and the configuration tube of the present invention;

[0032] Figure 3 is a cross-sectional schematic diagram of the internal structure of the pretreatment tank and the mixing tank of the present invention;

[0033] Figure 4 is a separate cross-sectional schematic diagram of the internal structure of the pretreatment tank of the present invention;

[0034] Figure 5 is a separate cross-sectional schematic diagram of the internal structure of the mixing tank of the present invention;

[0035] Figure 6 is a schematic diagram of the cooperation between the extension rod and the mixing component structure of the present invention;

[0036] Figure 7 is a separate schematic diagram of the mixing component structure of the present invention.

[0037] In the figure: 1, pretreatment tank; 2, mixing tank; 3, grinding tank; 4, filtering tank; 5, filter screen; 6, frame; 7, motor; 8, electric push rod; 9, grinding disc; 10, extension shaft; 11, extension rod; 12, cleaning brush; 13, titration head; 14, base; 15, elbow pipe; 16, burette; 17, configuration pipe; 18, mixing assembly; 181, mounting plate; 182, first fixed seat; 183, second fixed seat; 184, mixing rod; 185, guide block; 186, fixed sleeve; 187, piston plate; 188, piston rod; 189, limit spring; 1810, fixed guide rail; 19, drain valve. Detailed implementation manner

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] As Figures 1 to 7 shown, in the embodiment of the present invention, a titration device for detecting the chloride ion content in concrete includes a pretreatment tank 1. The bottom end of the pretreatment tank 1 is fixedly communicated with a mixing tank 2. The top end of the pretreatment tank 1 is fixedly installed with a frame 6. The bottom end of the outer side of the mixing tank 2 is fixedly installed with a base 14. One side of the bottom end of the mixing tank 2 is fixedly communicated with a drain valve 19. One side of the mixing tank 2 near the top end is fixedly communicated with a titration head 13. One end of the outer side of the pretreatment tank 1 is fixedly installed with a burette 16 through a locking frame. The top end of the burette 16 is fixedly communicated with a configuration pipe 17. The bottom end of the burette 16 is fixedly communicated with an elbow pipe 15. The elbow pipe 15 is communicated with the titration head 13. The top end of the frame 6 is fixedly installed with a motor 7. The output shaft of the motor 7 is fixedly installed with an electric push rod 8 located below the frame 6. The bottom end of the output shaft of the electric push rod 8 is fixedly installed with a grinding disc 9. The middle part of the bottom end of the grinding disc 9 is fixedly installed with an extension shaft 10. The bottom end of the extension shaft 10 is fixedly connected with an extension rod 11. The bottom end of the extension rod 11 penetrates through the bottom end of the pretreatment tank 1 and is fixedly connected with a mixing assembly 18 located inside the mixing tank 2. The mixing assembly 18 rotates relative to the mixing tank 2.

[0040] Before the titration test, first, an appropriate volume of nitric acid solution needs to be injected into the mixing tank 2, and the concrete sample is injected into the pretreatment tank 1. At this time, the concrete enters the grinding tank 3, and a potassium chromate indicator is configured in the configuration pipe 17 for use as needed.

[0041] As Figure 1 and Figure 3 as well as Figure 4As shown in the figure, a grinding groove 3 is provided at the top end of the pretreatment tank 1 on the outer side of the grinding disc 9, and a filtering groove 4 is provided at the bottom end of the pretreatment tank 1 on the outer side of the extension rod 11. The extension shaft 10 is movably sleeved between the bottom end of the grinding groove 3. A filter screen 5 is fixedly installed at the bottom end of the pretreatment tank 1 directly below the filtering groove 4. A cleaning brush 12 is fixedly installed at the top end of the outer side of the extension rod 11 inside the filtering groove 4.

[0042] Example: Before the titration test of the chloride ion content of concrete, at this time, the concrete sample can enter the inside of the grinding groove 3. At this time, according to the size of the concrete sample, the length of the electric push rod 8 can be adjusted to change the gap between the bottom end of the grinding disc 9 and the grinding groove 3. By starting the motor 7, the electric push rod 8 rotates accordingly and drives the grinding disc 9 at the bottom end to rotate. At this time, the grinding disc 9 can grind the concrete inside the grinding groove 3. The ground particles then enter the inside of the filtering groove 4 and enter the inside of the mixing tank 2 after being filtered by the filter screen 5, and are mixed with the nitric acid solution inside to obtain a standard solution.

[0043] By arranging an electric push rod 8, a grinding disc 9, a grinding groove 3 and a filtering groove 4 at the top end of the mixing tank 2, and using their mutual cooperation to achieve automatic grinding and filtering before titration, and the grinding and filtering can be carried out simultaneously with mixing and stirring, so that only the concrete sample and the nitric acid solution need to be poured to obtain a standard solution, without the need for external devices for assistance and the transfer of the solution, which can effectively avoid the pollution of the solution and simplify the operation steps, and improve the test accuracy.

[0044] As Figure 4 shown, when the electric push rod 8 is at its maximum tensile length, the bottom end of the grinding disc 9 is close to the bottom end of the grinding groove 3, and the bottom end of the cleaning brush 12 is in contact with the top end of the filter screen 5.

[0045] When the particles of the concrete fragments are too large and block the filter screen 5, at this time, the electric push rod 8 can be opened and driven to extend. At this time, the grinding disc 9 descends accordingly, reducing the gap between it and the grinding groove 3. At the same time, the cleaning brush 12 descends until it is in contact with the top end of the filter screen 5. At this time, the rotation of the grinding disc 9 can drive the cleaning brush 12 to rotate circumferentially relative to the filter screen 5 to automatically clean the surface of the filter screen 5, completing the automatic cleaning process.

[0046] As Figure 3 and Figure 5 as well as Figure 6 and Figure 7As shown in the figure, the mixing assembly 18 includes a mounting plate 181. The top end of the mounting plate 181 is connected to the bottom end of the extension rod 11. The mixing assembly 18 further includes a fixed sleeve 186 located below the mounting plate 181. The fixed sleeve 186 is movably connected to the middle of the bottom end of the mixing tank 2. The fixed sleeve 186 rotates relative to the mixing tank 2. The bottom end of the mounting plate 181 is fixedly connected to a piston rod 188. The bottom end of the piston rod 188 passes through the top end of the fixed sleeve 186 and is fixedly connected to a piston plate 187 located inside the fixed sleeve 186. The piston plate 187 moves up and down relative to the fixed sleeve 186. The outer side surface of the piston rod 188 is movably sleeved with a limiting spring 189 located inside the fixed sleeve 186. The upper and lower ends of the limiting spring 189 are respectively connected to the top end of the inner cavity of the fixed sleeve 186 and the top end of the piston plate 187. At an equal angle near the bottom end of the outer side surface of the fixed sleeve 186, fixed guide rails 1810 are fixedly installed. At an equal angle at the bottom end of the mounting plate 181, first fixing seats 182 are fixedly installed. One end of each first fixing seat 182 away from the mounting plate 181 is movably connected to a mixing rod 184 through a rotating shaft. One end of each mixing rod 184 away from the first fixing seat 182 is movably connected to a second fixing seat 183 through a rotating shaft. The bottom ends of the second fixing seats 183 are fixedly connected to guide blocks 185. The guide blocks 185 are movably clamped with the fixed guide rails 1810.

[0047] Embodiment: When the grinding disc 9 rotates, it can synchronously drive the extension rod 11 to rotate. At this time, the piston rod 188 and the fixed sleeve 186 at the bottom end rotate accordingly, and drive the mixing rod 184 on the outer side surface to rotate circumferentially. At this time, the mixing rod 184 can mix and stir the standard solution and the titrated solution located inside the mixing tank 2 to complete sufficient mixing.

[0048] And when the concrete sample particles decrease, due to the descent of the extension rod 11, at this time, the piston rod 188 and the mounting plate 181 can be driven to descend. At this time, the mixing rod 184 is subjected to a force accordingly, and the mixing rod 184 is driven to deflect outward, and drives the guide block 185 to displace toward the outer side surface of the fixed guide rail 1810. At this time, the mixing rod 184 displaces toward the inner side surface of the mixing tank 2. At this time, the mixing range increases accordingly. On the contrary, when the electric push rod 8 shortens, the mixing range decreases accordingly.

[0049] By utilizing the previous grinding process, it can realize the mixing and stirring process while grinding. At the same time, when the concrete fragments decrease and the filter screen 5 is cleaned, due to the descent of the extension rod 11, the mixing range of the mixing assembly 18 increases accordingly, realizing the variability of the mixing range. And the whole process only needs to control the length of the electric push rod 8, effectively improving the mixing quality, improving the corresponding mixing efficiency, and finally improving the accuracy of the titration test.

[0050] A titration method for a titration device for detecting the chloride ion content in concrete includes the following steps:

[0051] S1: First, pour the nitric acid solution into the interior of the mixing tank 2, and inject the concrete sample through the top of the pretreatment tank 1 into the interior of the grinding tank 3. Then, turn on the motor 7 to drive the electric push rod 8 to rotate. At this time, the grinding disc 9 rotates accordingly, and grinds the concrete located inside the grinding tank 3;

[0052] S2: After the grinding of the concrete is completed, it can be filtered through the filter screen 5 and enter the interior of the mixing tank 2 for temporary storage. At the same time, the electric push rod 8 can be turned on to drive the grinding disc 9 to move downward. At this time, the extension shaft 10 and the extension rod 11 move downward accordingly until the cleaning brush 12 contacts the filter screen 5, and the surface of the filter screen 5 is cleaned by the circumferential rotation of the cleaning brush 12;

[0053] S3: The crushed concrete can enter the interior of the mixing tank 2 and be mixed with the nitric acid solution to obtain a standard solution. At this time, the solution can be prepared through the preparation pipe 17. Add the potassium chromate indicator into the interior of the preparation pipe 17, and titrate it into the interior of the mixing tank 2 through the burette 16, the elbow pipe 15, and the titration head 13 to complete the titration process;

[0054] S4: At the same time, the rotation of the electric push rod 8 can synchronously realize the rotation of the extension rod 11. At this time, the mixing rod 184 rotates circumferentially accordingly, completing the mixing process of the solution inside the mixing tank 2. And when the extension rod 11 moves downward, at this time, the mixing rod 184 can rotate outwardly, and at this time, the mixing range increases, completing the mixing process of the solution in a large range;

[0055] S5: When the color of the solution changes significantly, it is the titration end point. According to the volume and concentration of the silver nitrate standard solution consumed by the titration, as well as the volume and weight of the solution to be measured, calculate the chloride ion content in the concrete.

[0056] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A titration device for detecting chloride ion content in concrete, comprising a pretreatment tank (1), characterized in that: The bottom end of the pretreatment tank (1) is fixedly connected to a mixing tank (2), the top end of the pretreatment tank (1) is fixedly mounted with a frame (6), the bottom end of the outer side of the mixing tank (2) is fixedly mounted with a base (14), one side of the bottom end of the mixing tank (2) is fixedly connected to a drain valve (19), the side of the mixing tank (2) close to the top end is fixedly connected to a burette head (13), one end of the outer side of the pretreatment tank (1) is fixedly mounted with a burette (16) via a locking frame, the top end of the burette (16) is fixedly connected to a configuration tube (17), the bottom end of the burette (16) is fixedly connected to a bend (15), and the bend (15) The frame (6) is connected to the titration head (13); a motor (7) is fixedly mounted on the top of the frame (6); an electric push rod (8) located below the frame (6) is fixedly mounted on the output shaft of the motor (7); a grinding disc (9) is fixedly mounted on the bottom end of the output shaft of the electric push rod (8); an extension shaft (10) is fixedly mounted in the middle of the bottom end of the grinding disc (9); an extension rod (11) is fixedly connected to the bottom end of the extension shaft (10); the bottom end of the extension rod (11) passes through the bottom end of the pretreatment tank (1) and is fixedly connected to a mixing assembly (18) located inside the mixing tank (2); and the mixing assembly (18) rotates relative to the mixing tank (2).

2. A titration device for detecting chloride ion content in concrete according to claim 1, characterized in that: The top of the pretreatment tank (1) is provided with a grinding groove (3) located on the outer side of the grinding disc (9), the bottom of the pretreatment tank (1) is provided with a filtering groove (4) located on the outer side of the extension rod (11), and the extension shaft (10) is movably sleeved with the bottom of the grinding groove (3).

3. A titration device for detecting chloride ion content in concrete according to claim 2, characterized in that: A filter screen (5) located directly below the filter tank (4) is fixedly mounted at the bottom end of the pretreatment tank (1), and a cleaning brush (12) located inside the filter tank (4) is fixedly mounted at the top end of the outer side of the extension rod (11).

4. A titration device for detecting chloride ion content in concrete according to claim 3, characterized in that: When the electric push rod (8) is at its maximum stretched length, the bottom end of the grinding disc (9) is close to the bottom end of the grinding groove (3), and the bottom end of the cleaning brush (12) is in contact with the top end of the filter screen (5).

5. A titration device for detecting chloride ion content in concrete according to claim 4, characterized in that: The mixing assembly (18) comprises a mounting plate (181), the top end of the mounting plate (181) being connected to the bottom end of the extension rod (11), and the mixing assembly (18) further comprises a fixing sleeve (186) located below the mounting plate (181), the fixing sleeve (186) being movably connected to the middle part of the bottom end of the mixing tank (2), and the fixing sleeve (186) is rotatable relative to the mixing tank (2).

6. A titration device for detecting chloride ion content in concrete according to claim 5, characterized in that: The bottom end of the mounting plate (181) is fixedly connected to a piston rod (188), the bottom end of the piston rod (188) passes through the top end of the fixing sleeve (186) and is fixedly connected to a piston plate (187) located inside the fixing sleeve (186), and the piston plate (187) moves up and down relative to the fixing sleeve (186).

7. A titration device for detecting chloride ion content in concrete according to claim 6, characterized in that: The outer side surface of the piston rod (188) is movably sleeved with a limit spring (189) located inside the fixed sleeve (186); the upper and lower ends of the limit spring (189) are respectively connected to the top of the inner cavity of the fixed sleeve (186) and the top of the piston plate (187); and a fixed guide rail (1810) is fixedly installed at an equal angle on the outer side surface of the fixed sleeve (186) near the bottom end.

8. A titration device for detecting chloride ion content in concrete according to claim 7, characterized in that: A first fixing seat (182) is fixedly mounted at an equal angle on the bottom end of the mounting plate (181); one end of the first fixing seat (182) away from the mounting plate (181) is movably connected to a mixing rod (184) via a rotating shaft; one end of the mixing rod (184) away from the first fixing seat (182) is movably connected to a second fixing seat (183) via a rotating shaft; the bottom end of the second fixing seat (183) is fixedly connected to a guide block (185); the guide block (185) is movably engaged with the fixed guide rail (1810).

9. The titration method of a titration device for detecting chloride ion content in concrete according to claim 8, characterized in that: The following steps are involved: S1: First, pour the nitric acid solution into the mixing tank (2), and inject the concrete sample into the grinding tank (3) through the top of the pretreatment tank (1), and turn on the motor (7) to drive the electric push rod (8) to rotate, and then the grinding disc (9) rotates accordingly and grinds the concrete in the grinding tank (3); S2: After the grinding, the concrete filter (5) is filtered and enters the interior of the mixing tank (2) for temporary storage. At the same time, the electric push rod (8) is turned on to drive the grinding disc (9) to move downward. At this time, the extension shaft (10) and the extension rod (11) move downward accordingly until the cleaning brush (12) contacts the filter (5). The surface of the filter (5) is cleaned by the circumferential rotation of the cleaning brush (12); S3: The crushed concrete enters the mixing tank (2) and is mixed with the nitric acid solution to obtain a standard solution. At this time, the solution is prepared through the preparation tube (17), potassium chromate indicator is added to the inside of the preparation tube (17), and titrated into the inside of the mixing tank (2) through the burette (16), the elbow (15) and the titration head (13), thereby completing the titration process; S4: At the same time, the rotation of the electric push rod (8) is synchronized with the rotation of the extension rod (11), and the mixing rod (184) rotates in the circumferential direction first, completing the mixing process of the solution inside the mixing tank (2), and when the extension rod (11) moves downward, the mixing rod (184) rotates toward the outer side, and the mixing range increases, completing a large-scale solution mixing process; S5: When the color of the solution changes significantly, it is the titration endpoint. The chloride ion content in the concrete can be calculated based on the volume and concentration of the silver nitrate standard solution consumed in the titration, as well as the volume and weight of the solution to be tested.

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