High-precision titration system for large-volume quantitative liquid

Abstract

The invention provides a high-precision titration system for large-dose quantification of liquid. The system comprises a mechanical driving unit and a control system unit, the mechanical driving unit also comprises a displacement sensor used for sensing the displacement amount of a syringe push handle, the control system unit comprises a flow field analysis unit for analyzing the fluid characteristics of to-be-titrated liquid, a fluid decision unit for deciding injection flow breakpoint control, laminar flow / turbulent flow control and position control, a control unit for obtaining force control, laminar flow control and position control, a motion command unit for calculating a driving motor operation instruction, and a motor-driven controller, the displacement sensor, the flow field analysis unit, the fluid decision unit, the control unit, the motion command unit and the motor-driven controller are connected in sequence in a data and transmission manner, and the motor-driven controller is connected with a driving motor in a control manner. Compared with the prior art, according to the titration system, quantified titration is realized through composite control of position, fluid state and fluid power, and the titration is accurate, rapid and reliable.

Description

technical field [0001] The invention relates to an automatic liquid dropping system, in particular to a pipeless automatic liquid dropping machine titration system. Background technique [0002] As a relatively advanced dye automatic color matching system, the pipeless automatic drip system is widely used in the production and scientific research fields related to dye color matching in printing and dyeing enterprises, university laboratories and laboratories. With the improvement of the technical level, the pipeless drip system has completely replaced the traditional manual liquid dispensing and color matching operation mode. The color matching operation process is completely controlled by the computer, which not only reduces the labor intensity of workers, but also improves The accuracy and efficiency of dosing are improved. [0003] The main components of the non-pipeline automatic dripping machine are: mother liquor display, X-Y servo motion platform, precision weighing ...

AI Technical Summary

Problems solved by technology

[0008] However, there are insurmountable problems in the above two control methods: the weighing closed-loop control method is at the end stage of the titration operation, because the difference between the feedback amount and the amount to be titrated is small, it is very difficult to carry out supplementary titration. It is prone to under-replenishment or over-replenishment; while the supplementary titration method is essentially a discrete control method, that is, the titration amount is replenished in the form of droplets. Therefore, when under-replenishment or over-replenishment occurs, the titration operation cannot seek the best Replenishment amount, even if there is an optimal replenishment amount, the form of the droplet will cause a step error in the titration operation, thereby reducing the titration accuracy; moreover, due to the precision electronic balance is easily affected by factors such as external temperature, humidity, vibration, etc. , coupled with the impact of the liquid column on the weighing pan during the titration operation, the precision electronic balance has a longer stabilization time. Therefore, the real-time performance of the feedback amount is poor, and the titration efficiency is extremely low; in addition, for volatile liquids or solution, when the weighing time is equivalent to the minimum volatilization time of the liquid, it is more difficult to obtain accurate feedback, and the accuracy of titration is more difficult to guarantee

[0009] Although the position open-loop control method removes the weighing link of the weighing closed-loop control method and improves the titration efficiency, but in the position control mode, the servo motor has problems such as overshoot and vibration that affect the rapid and accurate positioning. The stepper motor has problems such as lost steps; moreover, the transmission ball screw has mechanical positioning errors due to problems such as machining and assembly; the automatic drip machine titration system has positioning errors caused by factors such as dead zones and gaps during final assembly. ;The above position positioning error factors will be superimposed on the position control amount of the syringe push handle when the automatic drip machine performs the titration operation, resulting in superimposed nonlinear factors on the assumed linear relationship, thus affecting the accuracy of the titration;

[0010] In addition, the above two titration methods do not consider the fluid characteristics of the liquid to be titrated. Different liquids have different characteristics during the titration process when the parameters such as density, viscosity, and flow rate are different. This characteristic also affects Improved Titration Accuracy

[0011] To sum up, although the traditional automatic drip machine titration system and its control method have a simple mechanism, low cost, and simple and direct quantitative titration, it is difficult to eliminate or compensate for the influence of the above-mentioned various inherent factors. Realize high-precision titration of quantitative liquid

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