An acid value detection automatic titrator with anti-liquid hanging and precise liquid adding structure

Abstract

This invention discloses an automatic acid value titrator with an anti-leaking and precise liquid addition structure, mainly relating to the field of testing instrument technology. It uses a two-stage flow control system composed of a high-precision feed drive component and a stepless flow adjustment component to match the requirements of the entire titration process. It can quickly pre-titrate at the beginning of the titration to shorten the detection cycle, and achieve precise micro-liquid addition near the endpoint to avoid over-titration, thus solving the problems of insufficient liquid addition accuracy and inaccurate endpoint control of traditional titrators. Furthermore, through the partitioned back suction micro-cavity formed by the elastic deformation structure and the inner wall of the titration tube, a momentary micro-negative pressure is generated by elastic deformation at the moment of sealing at the endpoint, forming a directional back suction of the residual titrant at the burette, thus solving the problems of viscous titrant stagnation and abnormal dripping.

Description

Technical Field

[0001] This invention relates to the field of testing instrument technology, specifically to an automatic titrator for acid value detection with a structure that prevents liquid residue buildup and ensures precise liquid addition. Background Technology

[0002] Electrode potential is determined by measuring the electromotive force of a galvanic cell composed of the electrode to be tested and the reference electrode. Therefore, potentiometric measuring instruments form a circuit with the reference electrode, the indicator electrode, and the measuring instrument to measure the electrode potential. Potentiometric measuring instruments are divided into two types: direct potentiometric measuring instruments and potentiometric titration measuring instruments. Potentiometric titration measuring instruments are analytical instruments that determine the endpoint by detecting the change in electrode potential during titration. They are widely used in chemical composition analysis in pharmaceutical, petrochemical, environmental protection, and scientific research institutions. The technical principle is based on the potential jump near the equivalence point and the endpoint is identified by the differential curve. It is suitable for colored, turbid solutions or scenarios where indicators are lacking.

[0003] For example, an automatic potentiometric titrator disclosed in CN105806994A includes a burette, a syringe pump, a potentiometric electrode, and a controller. Although it has an automatic dispensing function, it is difficult to accurately control the amount of liquid added when the liquid addition rate is fixed and the titration endpoint is approaching. On the other hand, for the titration process of viscous liquids, the "re-suction after titration" method at the end of the titration will draw back the already measured liquid, which will directly affect the accuracy of liquid addition.

[0004] Therefore, the present invention proposes a solution. Summary of the Invention

[0005] The purpose of this invention is to provide an automatic titrator for acid value detection with an anti-leaking and precise liquid addition structure, so as to solve the technical defects mentioned in the background art.

[0006] The objective of this invention can be achieved through the following technical solution: an automatic titrator for acid value detection with anti-leaking and precise liquid addition structure, comprising a machine base, wherein a support seat and a bracket are provided on the machine base, and the bracket is provided on the upper rear side of the support seat; A titration structure includes a titration tube suspended on a hanging rod, a burette for dispensing liquid is installed at the lower end of the titration tube, and a conical sealing surface is provided at the bottom of the titration tube. The inner diameter of the conical sealing surface gradually decreases from top to bottom, and the bottom inner diameter is the same as the inner diameter of the titration tube. The titration execution assembly includes a titration valve seat disposed inside the titration main tube. An elastic collar is stacked at the lower end of the titration valve seat. The inner and outer sides of the elastic collar together form a back suction microcavity with the titration main tube. A sealing valve core matching the conical sealing surface is installed at the lower end of the elastic collar. The sealing valve core has a liquid outlet microhole communicating with the back suction microcavity.

[0007] The method is further configured such that: a main injection pump for controlling the dripping speed and metering titration is installed at the upper end of the titration main tube; an axial sleeve is connected to the output end of the main injection pump; and a hanging plate adapted to the inner wall of the titration main tube is connected to the lower end of the axial sleeve.

[0008] A further configuration is provided: a spring is installed at the lower end of the hanging plate, and the lower end of the spring is connected to the titration valve seat.

[0009] A further configuration is provided: a liquid outlet valve is embedded on the inner side of the lower end of the titration main tube near the titration nozzle, the liquid outlet valve is provided with a liquid outlet valve core for liquid outlet control, and a motor for controlling the deflection angle of the liquid outlet valve core is installed on the outside of the titration main tube.

[0010] The device is further configured such that: a shaft connecting block is installed on the inner ring side of the elastic collar, and connecting posts are arranged intersecting the shaft connecting block; the connecting posts at the top and bottom are respectively connected to the titration valve seat and the sealing valve core.

[0011] Further configuration: the shaft connecting block, connecting column, and elastic collar are all made of elastic material; the back suction microcavity between the shaft connecting block and connecting column and the elastic collar is connected to the liquid outlet micropore in the middle; and the back suction microcavity between the elastic collar and the inner wall of the titration tube is connected to the liquid outlet micropore on the outer side.

[0012] A further configuration is provided: the portion of the titration main tube corresponding to the upper side of the back suction microcavity is fitted with an inlet tube for injecting the acid value detection titrant.

[0013] The device is further configured such that: a display screen is provided on the front side of the machine, and a titration control module electrically connected to the display screen is provided inside the machine for real-time control of titration.

[0014] A further provision is made: an outer sleeve is provided around the titration tube, and the outer sleeve is used for titration protection.

[0015] The present invention has the following beneficial effects: 1. To address the issues of inaccurate titration due to easy liquid residue buildup and insufficient liquid addition precision during automatic titration, a two-stage flow control system consisting of a high-precision feed drive component and a stepless flow adjustment component is employed. This system can match the requirements of the entire titration process. Rapid pre-titering at the initial stage shortens the detection cycle, while precise micro-liquid addition near the endpoint avoids over-titering. Simultaneously, the feed stroke accurately measures the volume of the titrant, and the conical hard-seal structure ensures leak-free shut-off and eliminates additional backflow interference. This solves the problems of insufficient liquid addition precision and inaccurate endpoint control in traditional titrators, improving the accuracy and repeatability of test results.

[0016] 2. Furthermore, the partitioned back-suction microcavities formed by the elastic deformation structure and the inner wall of the titration tube generate an instantaneous micro-negative pressure at the moment of sealing at the endpoint, forming a directional back-suction of the residual titrant at the burette. This solves the problems of viscous titrant hanging and abnormal dripping. Moreover, the back-suction only acts on the residual liquid at the end of the flow channel, without affecting the measurement accuracy. The stepless continuous flow channel avoids titrant retention. The accompanying protective structure and automatic control module improve the stability of the device operation and the detection efficiency. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a side sectional view of the present invention; Figure 3 This is a partial cross-sectional schematic diagram of the titration structure of the present invention; Figure 4 This is a cross-sectional view of the titration execution component of the present invention; Figure 5 This is a cross-sectional view of the titration structure of the present invention in a standby sealed state; Figure 6 In this invention Figure 5 Enlarged view of point A; Figure 7 This is a schematic diagram showing the state transition of the titration structure in the present invention when it is in the titration feed state and the endpoint cutoff anti-liquid state.

[0019] In the diagram: 1. Machine base; 2. Support seat; 3. Display screen; 4. Bracket; 5. Hanging rod; 6. Titration main pipe; 7. Main injection pump; 8. Outer tube; 9. Dosing nozzle; 10. Inlet pipe; 11. Motor; 12. Axial sleeve; 13. Hanging plate; 14. Spring; 15. Discharge valve; 16. Discharge valve core; 17. Titration valve seat; 18. Elastic collar; 19. Sealing valve core; 20. Shaft connecting block; 21. Connecting column; 22. Discharge micro-orifice; 23. Conical sealing surface. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1: To address the problems of inaccurate titration caused by easy liquid residue buildup and insufficient liquid addition accuracy during automatic titration, the following technical solution is proposed: Reference Figure 1 - Figure 7 As shown, the automatic titrator for acid value detection with anti-liquidation and precise liquid addition structure in this embodiment includes a machine base 1, on which a support base 2 and a bracket 4 are provided, and the bracket 4 is located on the upper rear side of the support base 2. The titration structure includes a titration tube 6 suspended on a hanging rod 5. A burette 9 for dispensing liquid is installed at the lower end of the titration tube 6. A conical sealing surface 23 is provided at the bottom of the titration tube 6. The inner diameter of the conical sealing surface 23 gradually decreases from top to bottom, and the bottom inner diameter is the same as the inner diameter of the titration tube 6. Reference Figure 6 As shown, the titration execution assembly includes a titration valve seat 17 disposed inside the titration main tube 6. An elastic collar 18 is stacked on the lower end of the titration valve seat 17. The inner and outer sides of the elastic collar 18 together with the titration main tube 6 form a back suction microcavity. A sealing valve core 19 matching the conical sealing surface 23 is installed on the lower end of the elastic collar 18. A liquid outlet microhole 22 communicating with the back suction microcavity is opened on the sealing valve core 19. Reference Figure 5 As shown, a main injection pump 7 for controlling the dripping speed and metering titration is installed at the upper end of the titration main tube 6. An axial sleeve 12 is connected to the output end of the main injection pump 7. A hanging plate 13 adapted to the inner wall of the titration main tube 6 is connected to the lower end of the axial sleeve 12. A spring 14 is installed at the lower end of the hanging plate 13. The lower end of the spring 14 is connected to the titration valve seat 17. A display screen 3 is installed on the front side of the machine 1. A titration control module electrically connected to the display screen 3 is installed inside the machine 1 for parameter acquisition, real-time control and data display during the titration process. An outer tube 8 is fitted on the outside of the titration main tube 6 for titration protection.

[0022] The basic motion principle of this embodiment includes three stages: standby sealing state, titration feeding state, and endpoint cutoff anti-liquidation state. Standby sealing state: In the standby sealing state, the push rod of the main injection pump 7 is in the initial upper limit position, the spring 14 is in the natural extension state, and the preload of the spring 14 pushes the titration valve seat 17, the elastic collar 18 and the sealing valve core 19 to move downward synchronously, so that the outer conical surface of the sealing valve core 19 is completely in contact with the conical sealing surface 23 at the bottom of the titration main tube 6, forming a conical hard seal, blocking the outflow channel of the titrant. At the same time, the elastic collar 18 is in its natural state, and the back suction microcavity formed by it and the inner wall of the titration main tube 6 is in the initial volume state.

[0023] Titration feed state: According to the titration requirements of acid value detection, the titration control module drives the push rod of the main injection pump 7 to feed downwards. Through the axial sleeve 12, the hanging plate 13 slides upwards along the inner wall of the titration main pipe 6, compressing the spring 14 and pushing the titration valve seat 17, the elastic collar 18 and the sealing valve core 19 to move upwards synchronously, so that the sealing valve core 19 and the conical sealing surface 23 are disengaged, forming an annular liquid outlet channel. At the same time, the feeding action of the main injection pump 7 applies pressure to the titrant in the titration main pipe 6. The titrant enters the back suction microcavity through the outer peripheral channel of the titration valve seat 17, and then enters the burette 9 through the liquid outlet microhole 22 on the sealing valve core 19 and the annular liquid outlet channel, completing the quantitative addition of the titrant. The feeding stroke and feeding speed of the main injection pump 7 can be precisely controlled by the titration control module to achieve high-precision measurement of the titrant volume and stepless adjustment of the dropping speed.

[0024] Endpoint cutoff and anti-liquidity-leaking state: When the titration control module detects the titration endpoint signal, it immediately drives the push rod of the main injection pump 7 to reset upwards, causing the hanging plate 13 to move upwards. The rebound force of the spring 14 pushes the titration valve seat 17, the elastic collar 18, and the sealing valve core 19 to reset upwards simultaneously, so that the outer conical surface of the sealing valve core 19 and the conical sealing surface 23 are fully fitted again, completing the hard seal cutoff of the liquid outlet channel; at the moment of sealing fit, the elastic collar 18 is subjected to the axial force of the sealing valve core 19 and the titration valve seat 17. The radial elastic deformation caused by compression instantly increases the volume of the back suction microcavity, creating a micro-negative pressure environment. This environment generates a directional back suction force on the residual titrant at the burette 9 port through the liquid outlet microhole 22, drawing the residual titrant back into the liquid outlet microhole 22 and the back suction microcavity. This prevents the titrant from forming a hanging or dripping pattern at the burette 9 port. At the same time, this back suction action only acts on the residual titrant at the end of the flow channel after sealing and will not affect the titrant already metered out by the main injection pump 7, thus ensuring the accuracy of titration.

[0025] Example 2: This example also includes a liquid outlet valve 15 embedded on the inner side of the lower end of the titration tube 6 near the titration nozzle 9. The liquid outlet valve 15 is provided with a liquid outlet valve core 16 for liquid outlet control. A motor 11 for controlling the deflection angle of the liquid outlet valve core 16 is installed outside the titration tube 6. A shaft connecting block 20 is installed on the inner ring side of the elastic collar 18, and connecting posts 21 are arranged intersecting with the shaft connecting block 20. The connecting posts 21 at the top and bottom are respectively connected to the titration valve seat 17 and the sealing valve core 19. The shaft connecting block 20, connecting column 21, and elastic collar 18 are all made of elastic material. The back suction microcavity between the shaft connecting block 20 and connecting column 21 and elastic collar 18 is connected to the liquid outlet microhole 22 in the middle. The back suction microcavity between the elastic collar 18 and the inner wall of the titration tube 6 is connected to the liquid outlet microhole 22 on the outer side. Multiple independent back suction channels avoid channel movement and pressure unevenness during the back suction process.

[0026] The upper part of the titration main tube 6 corresponding to the back suction microcavity is fitted with an inlet tube 10 for injecting the acid value detection titrant; the inlet tube 10 is fitted on the tube wall of the titration main tube 6 corresponding to the back suction microcavity, and the outer end of the inlet tube 10 is connected to the titrant storage unit for continuous replenishment of the acid value detection titrant, ensuring the stability of the liquid supply during continuous titration.

[0027] Based on Example 1, in this embodiment, during the titration process, the titration control module can synchronously adjust the feed speed of the main injection pump 7 and the output angle of the motor 11 according to the titration progress. In the initial stage of titration, the drive motor 11 drives the liquid outlet valve core 16 to deflect to a large opening angle, which, together with the rapid feed of the main injection pump 7, enables rapid pre-titration of the titrant and shortens the detection cycle. Furthermore, as the titration endpoint approaches, the drive motor 11 deflects the outlet valve core 16 to a micro-opening angle, which, in conjunction with the micron-level feed of the main injection pump 7, enables nano-level micro-drop of the titrant, avoiding over-titration and significantly improving the titration accuracy of acid value detection. During the final stop anti-liquidation process, the shaft connecting block 20 and the connecting column 21 undergo elastic deformation synchronously with the axial compression of the elastic collar 18, so that the inner back suction microcavity and the outer back suction microcavity simultaneously generate a micro negative pressure environment with increased volume. Through the corresponding connected liquid outlet microhole 22, a uniform and fully covered back suction force is generated on the residual titrant at the burette 9 port, further improving the anti-liquidation effect. At the same time, multiple independent back suction microcavities can avoid anti-liquidation failure caused by blockage of a single flow channel, improving the reliability of the device operation.

[0028] Example 3: This example combines the technical content of Example 1 and Example 2 to form the following control method: Step 1: Titration preparation stage. Place the acid value sample to be tested on the carrier 2, immerse the reference electrode and indicator electrode in the sample to be tested, and electrically connect the electrodes to the titration control module in the instrument 1. Inject a preset volume of acid value detection titrant into the titration main tube 6 through the inlet pipe 10. The titration control module drives the main injection pump 7 and motor 11 to reset, so that the sealing valve core 19 and the conical sealing surface 23 are in contact and sealed, and the outlet valve core 16 is in the closed state, completing the preparation work before titration. Step 2: In the pre-titration stage, the titration control module drives the motor 11 to deflect the outlet valve core 16 to the preset large flow angle, and at the same time drives the main injection pump 7 to feed downwards at a preset rapid feed rate, pushing the sealing valve core 19 to disengage from the conical sealing surface 23. The titrant is rapidly dripped into the sample to be tested through the back suction microcavity, outlet microhole 22, outlet valve 15 and titration nozzle 9. The titration control module collects the potential signal of the sample to be tested in real time through electrodes to determine the titration progress. Step 3: In the micro-titration stage, when the titration control module detects a sudden jump in the potential signal and determines that the titration endpoint is approaching, it immediately drives the motor 11 to deflect the liquid outlet valve core 16 to a micro-flow angle, and at the same time reduces the feed rate of the main injection pump 7 to the preset micro-feed rate, so as to realize the micro- and uniform addition of the titrant, and collect the rate of change of the potential signal in real time until the titration endpoint signal with a sudden jump in potential is detected. Step 4: Endpoint cutoff and anti-liquidation stage. When the titration endpoint signal is detected, the titration control module synchronously drives the main injection pump 7 to reset upward and the motor 11 drives the outlet valve core 16 to rotate to the closed state. The rebound force of the spring 14 pushes the sealing valve core 19 to complete the fit and seal with the conical sealing surface 23. The elastic collar 18, shaft connecting block 20 and connecting column 21 are subjected to axial compression and generate elastic deformation, so that the back suction microcavity generates a micro negative pressure back suction force, which draws the titrant remaining at the port of the burette 9 back into the outlet microhole 22, thus completing the precise cutoff and anti-liquidation treatment of the titration endpoint. Step 5: Titration reset stage. After completing a single titration test, the titration control module displays the acid value test result on the display screen 3, and at the same time drives the main injection pump 7 to reset to the initial position. The titrant is replenished through the inlet pipe 10 to prepare for the next test. If continuous testing is required, the above process can be repeated.

[0029] In summary, the two-stage flow control system, consisting of a high-precision feed drive component and a stepless flow adjustment component, can match the requirements of the entire titration process. It enables rapid pre-titering in the early stages of titration to shorten the detection cycle, and achieves precise micro-volume addition near the endpoint to avoid over-titering. At the same time, it accurately measures the volume of titrant through the feed stroke, and with the conical hard seal structure, it achieves leak-free cutoff and no additional backflow interference. This solves the problems of insufficient liquid addition accuracy and inaccurate endpoint control in traditional titrators, and improves the accuracy and repeatability of the test results. Furthermore, the partitioned back-suction microcavities formed by the elastic deformation structure and the inner wall of the titration tube generate instantaneous micro-negative pressure at the moment of sealing at the end point, forming a directional back-suction of the residual titrant at the burette. This solves the problems of viscous titrant hanging and abnormal dripping. Moreover, the back-suction only acts on the residual liquid at the end of the flow channel, without affecting the measurement accuracy. The stepless continuous flow channel avoids titrant retention. The accompanying protective structure and automatic control module improve the stability of the device operation and the detection efficiency.

[0030] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. An automatic titrator for acid value detection with a structure that prevents liquid residue buildup and ensures precise liquid addition, characterized in that, include: A machine base (1) is provided with a support seat (2) and a bracket (4), and the bracket (4) is located on the upper rear side of the support seat (2); The titration structure includes a titration tube (6) suspended on a hanging rod (5), a burette (9) for dispensing liquid is installed at the lower end of the titration tube (6), and a conical sealing surface (23) is provided at the bottom of the titration tube (6). The inner diameter of the conical sealing surface (23) gradually decreases from top to bottom, and the bottom inner diameter is the same as the inner diameter of the titration tube (6). The titration execution assembly includes a titration valve seat (17) disposed inside the titration main tube (6). An elastic collar (18) is stacked on the lower end of the titration valve seat (17). The inner and outer sides of the elastic collar (18) together with the titration main tube (6) form a back suction microcavity. A sealing valve core (19) matching the conical sealing surface (23) is installed on the lower end of the elastic collar (18). A liquid outlet microhole (22) communicating with the back suction microcavity is opened on the sealing valve core (19).

2. The automatic titrator for acid value detection with anti-leaking and precise liquid addition structure according to claim 1, characterized in that, The upper end of the titration tube (6) is equipped with a main injection pump (7) for controlling the dripping speed and metering titration. The output end of the main injection pump (7) is connected to an axial sleeve (12), and the lower end of the axial sleeve (12) is connected to a hanging plate (13) adapted to the inner wall of the titration tube (6).

3. The automatic titrator for acid value detection with anti-leaking and precise liquid addition structure according to claim 2, characterized in that, A spring (14) is installed at the lower end of the hanging plate (13), and the lower end of the spring (14) is connected to the titration valve seat (17).

4. The automatic titrator for acid value detection with anti-leaking and precise liquid addition structure according to claim 1, characterized in that, The titration main tube (6) is fitted with a liquid outlet valve (15) on the inner side of the lower end near the burette (9). The liquid outlet valve (15) is provided with a liquid outlet valve core (16) for liquid outlet control. The titration main tube (6) is equipped with a motor (11) for controlling the deflection angle of the liquid outlet valve core (16).

5. The automatic titrator for acid value detection with anti-leaking and precise liquid addition structure according to claim 1, characterized in that, A shaft connecting block (20) is installed on the inner ring side of the elastic collar (18), and a connecting column (21) is arranged intersecting the shaft connecting block (20). The connecting column (21) at the top and bottom is connected to the titration valve seat (17) and the sealing valve core (19) respectively.

6. The automatic titrator for acid value detection with anti-leaking and precise liquid addition structure according to claim 5, characterized in that, The shaft connecting block (20), connecting column (21) and elastic collar (18) are all made of elastic material. The back suction microcavity between the shaft connecting block (20) and connecting column (21) and elastic collar (18) is connected to the liquid outlet microhole (22) in the middle. The back suction microcavity between the elastic collar (18) and the inner wall of the titration tube (6) is connected to the liquid outlet microhole (22) on the outer side.

7. The automatic titrator for acid value detection with anti-leaking and precise liquid addition structure according to claim 6, characterized in that, The titration main tube (6) is fitted with an inlet tube (10) on the upper side of the back suction microcavity for injecting the acid value detection titration solution.

8. The automatic titrator for acid value detection with anti-leaking and precise liquid addition structure according to claim 1, characterized in that, The machine (1) is equipped with a display screen (3) on the front side, and a titration control module electrically connected to the display screen (3) is installed inside the machine (1) for real-time control of titration.

9. The automatic titrator for acid value detection with anti-leaking and precise liquid addition structure according to claim 1, characterized in that, The titration tube (6) is covered with an outer tube (8), which is used for titration protection.

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