CN105606760A - Automatic titration apparatus for analytical instrument - Google Patents

Abstract

The invention provides an automatic titration apparatus for an analytical instrument. The automatic titration apparatus comprises an electromagnetic stirring device, a feeding and discharging liquid metering system, a fastening mechanism, a titration end point monitoring device and a controlling and calculating unit, wherein the electromagnetic stirring device has only one liquid feeding and discharging opening in the bottom and is provided with a central through hole. The apparatus can be used for photometric titration and potentiometric titration, and is simple to install and low in cost.

Description

For the automatic titration device of analytical instrument

Technical field

The application relates to the titration outfit of analytical instrument, particularly a kind of automatic titration device.

Background technology

Titration is that one adds standard liquid in analyzed solution by amount, and color, precipitation or the conductivity variations etc. that in titration process, cause with component to be measured, titrating solution, product are determined reaction end, the method for analytical solution composition. The principle difference of judging by titration end-point, titration can be divided into photometric titration, constant-current titration, coulometric titration etc.; By the difference of reaction principle, can be divided into soda acid, redox, precipitation or complexometry etc.

Full-automatic titration outfit generally includes titration cell, enters discharge opeing metering system, mixes homogenizer, titration end-point checkout gear, control computing unit and retention mechanism. The reagent such as analyzed solution, developer is injected titration cell by feed liquor system, after mixing homogenizer and mixing, then starts to splash at a slow speed standard liquid (also claiming titrating solution) by feed liquor system and carry out titration. In the overall process of titration, homogenizing mixing arrangement and titration end-point checkout gear keep duty always, and can scatter rapidly and come and analyzed solution reaction with the titrating solution that ensures to splash into, and can be by end point determination device Real-Time Monitoring. After arriving titration end-point, the titrating solution consumption being recorded by metering device can be extrapolated the concentration of analyzed solution. Finally, raffinate is discharged titration cell by drainage system, and with after distilled water detergent line and titration cell, titration process comes to an end.

In at present known all kinds of automatic titration devices, analyzed solution, titrating solution, leakage fluid dram inject by different pipelines more than two-way at least and discharge titration cell. The for example disclosed titration outfit of patent ZL01257186.5, sample, developer and titrating solution are injected by the injection port 3 of titration cell 2 left side walls (end) below, raffinate is discharged by the evacuation port 7 of titration cell 2 right side wall belows, the bottom design of titration cell 2 is flat, be used for placing magnetic stir bar, the magnetic stirring apparatus 12 that magnetic stir bar is installed by titration cell 2 belows drives. The discharge opeing metering system that enters of this patent comprises a multiple valve 1, two peristaltic pumps 8 and 9, three plunger displacement pump B1, B2 and B3. Enter discharge opeing metering system cost high, enter discharge opeing flow process complexity.

The disclosed titration outfit of patent ZL200820035078.7, water sample, reagent, titrating solution are injected by top water sample pipe 2-1, Reagent Tube 2-2 and the buret 2-3 of titration cell respectively, and raffinate is discharged by the drain pipe 2-5 of titration cell below. The bottom design of titration cell is flat, for placing magnetic stir bar. Other patents have similar design as ZL200820240834.X etc.

Above-mentioned known design has following deficiency:

1. the pipe interface of titration cell is too much, and this has not only increased the quantity and the cost that enter the required valve of discharge opeing metering system, pump, and the also increase greatly of the probability of leakage, has also increased the complexity that titration cell is installed simultaneously.

2. owing to entering discharge opeing metering system complexity, the therefore flow process complexity of feed liquor, discharge opeing and titration.

3. because titration cell adopts flat design, therefore easy residual waste liquid, is the precision that ensures that measure next time, needs to consume more clean water and cleans titration cell.

4. stir in design at the titration outfit of known employing Electromagnetic Drive, the bottom of titration cell is all designed to platybasic type and adopts column type stirrer. Because column type stirrer is only retrained by magnetic force, therefore, in the time that this device is worked under boats and ships or vehicle etc. jolt state, stirrer is easily thrown off operating position, causes stirring losing efficacy or damaging device in titration cell.

At known pipeline from the design of titration cell top or side access, because various pipelines have tied up the space of titration cell top or side, easily produce interference with the titration end-point checkout gear such as photometer, electrode, therefore this design has increased the design difficulty of instrument miniaturization.

Summary of the invention

Prior art, because titration cell pipe interface is too much, is entered discharge opeing metering system, electromagnetic mixing apparatus and feed liquor discharge opeing flow process also comparatively complicated accordingly. Therefore, be the design requirement of the small-sized automatic titration device of 10 milliliters of left and right for full volume, prior art exists many drawbacks such as complex structure, assembling is difficult, system reliability is poor, equipment miniaturization is difficult. In order to solve above-mentioned deficiency of the prior art, the application provides a kind of unique leakage fluid dram that enters that has, and carries out the automatic titration device of feed liquor titration, stirring and delicate metering from bottom.

The technical scheme that realizes the application is: a kind of small-sized automatic titration device, comprises that one has only in bottom

One enter the titration cell of leakage fluid dram, electromagnetic mixing apparatus with central through hole, enter discharge opeing metering system, retention mechanism, titration end-point checkout gear ORP electrode (ORP:Oxidation-ReductionPotential, oxidation-reduction potential; ORP electrode is hereinafter to be referred as " electrode ") and control computing unit.

Described titration cell has and only has one to enter discharging tube, entering discharging tube combines with the bottommost of titration cell, all liquid all injects or discharges from entering discharging tube, the end that enters discharging tube by pipeline with described enter in discharge opeing metering system one of multiposition valve distribute port to be connected.

There is a through hole at the center of described electromagnetic mixing apparatus, the internal diameter of through hole is greater than the external diameter that enters discharging tube of titration cell, electromagnetic mixing apparatus is fixed on the bottom in fastening framework in described retention mechanism, and the discharging tube that enters of titration cell is connected with the pipeline that enters discharge opeing metering system through the through hole at electromagnetic mixing apparatus center from the top of electromagnetic mixing apparatus.

Described titration cell upper end is uncovered, and titration cell body bottom has an elongated discharging tube that enters to draw on axially, and entering discharging tube and titration cell joint portion, to be processed with an internal diameter be the reducing of 1.5 millimeters. As preferably, the shape of titration cell is column type, and bottom is funnel type. As preferably, the material of titration cell is selected the glass-like materials transparent, anticorrosive, intensity is high.

The application compared with prior art, has the following advantages:

1. titration cell has and only has one to enter leakage fluid dram, and it is simple in structure, and the cost of producing, assembling is low.

2. because titration cell only has one to enter leakage fluid dram, entering discharge opeing metering system only needs each one of liquid storage ring, multiposition valve, plunger displacement pump, two-position three-way valve, feed liquor detector of liquid and titrating solution detector, therefore enters that discharge opeing flow process is simple, system cost is low.

3. because titration cell enters discharge opeing from bottom, for the installation of top titration end-point checkout gear implements to provide maximum space and the free degree, therefore,, under existing technical conditions, such structure is conducive to realize the design of the device of mini-burette of full volume below 10 milliliters.

4. because titration cell bottom adopts funnel-shaped design, and enter discharging tube and be positioned at the shallow hopper centre of titration cell bottom, therefore discharge opeing is thorough, does not stay raffinate, does not need a large amount of rinse water to rinse. Meanwhile, the application's electromagnetic mixing apparatus adopts the central through hole design matching with titration cell structure, and not only compact conformation is simple and practical, and production assembly cost is low.

5. the magnetic stirring of platypelloid type matches with titration cell camber line bottom, and electromagnetic mixing apparatus still can normally be worked in the working environment rocking jolting, and stirrer can not be thrown off operating position or damage the interior electrode of titration cell.

6. coordinate high precision piston pump, the titrating solution detector that install the below of electromagnetic mixing apparatus both can have been realized the accurate measurement to titration feed liquor, can eliminate again the impact of bubble on titration precision in titrating solution.

Brief description of the drawings

Fig. 1 is the application's structural representation.

Detailed description of the invention

As shown in Figure 1, a kind of automatic titration device of OPR electrode as titration end-point judgement that adopt, be applied in iron ammonium sulfate in the titration of potassium bichromate, described automatic titration device comprises: titration cell 10, magnetic stirring 20, circular magnetic block 31A and 31B, gear traffic cycle 32, bearing pair 33, electromagnetic mixing apparatus casing frame 34, pinion 35, motor 36, fastening framework 40, O RunddichtringO 41, clip 42, bottom support knob 43, polytetrafluoroethylene (PTFE) hard tube 44, compress knob 45, holddown spring 46, titration cell lid 47, multiposition valve 50, liquid storage ring 51, feed liquor detector of liquid 52, two-position three-way valve 53 and plunger displacement pump 54 (stepper motor does not draw), titrating solution detector 55 and ORP electrode 60.

The body 11 of described titration cell 10 adopts the uncovered cylindrical design in upper end, and material adopts the glass-like materials transparent, anticorrosive, intensity is high. Titration cell bottom 12 is designed to funnel type, and bottom is blown out a slender glass tube 13 and drawn as entering discharging tube. Enter discharging tube 13 and be titration cell 10 unique enter leakage fluid dram, sample to be tested, titrating solution, titration waste liquid etc. all inject or discharge from this mouth. For preventing in titration cell that liquid still can flow down along tube wall in the time that the E of multiposition valve 50 mouth is closed, be processed with a diameter in titration cell bottom 12 and the joint portion of entering leakage fluid dram 13 and be the reducing 14 of 1.5 millimeters. Due to the surface tension of liquid self and the support effect of inner air tube, the liquid in titration cell 10 can not flow down along the sidewall that enters leakage fluid dram 13.

Two circular magnetic block 31A and the 31B of described electromagnetic mixing apparatus are mutually 180 degree angles, adopt interference fit to be arranged on the gear traffic cycle 32 of engineering plastics system. There is an aperture to be greater than titration cell to enter the central through hole of discharging tube 13 external diameters at gear traffic cycle 32 centers. Gear traffic cycle 32 is arranged on the inner ring of bearing pair 33 by interference fit. The outer ring of bearing pair 33 is arranged on casing frame 34 by interference fit. On the casing frame 34 of electromagnetic mixing apparatus, also by interference fit, motor 36 is installed, motor 36 axle upper end cuffs have a reduction pinion teeth 35. When work, rotated by motor 36 driven wheel traffic cycles 32, drive magnetic stirring 20 that is placed on 11 places, titration cell bottom to rotate, at the uniform velocity agitated liquid.

The below of described electromagnetic mixing apparatus is provided with a titrating solution detector 55, and during for detection of titration, when titrating solution arrives in discharging tube 13 or the titrating solution that passes through whether have bubble. As preferably, can select the detector of liquid based on light transmission or total reflection principle. There is a through hole at titrating solution detector 55 center, and discharging tube 13 external diameters that enter of its bore and titration cell 10 form matched in clearance just.

Claims (2)

1. an automatic titration device, comprise titration cell, enter discharge opeing metering system, electromagnetic mixing apparatus, titration end-point checkout gear, retention mechanism and control computing unit, it is characterized in that: described titration cell (10) has and only have one to enter discharging tube (13), entering discharging tube (13) combines with the bottommost of titration cell (10), all liquid all injects or discharges from entering discharging tube (13), the end that enters discharging tube (13) by pipeline (44) with described in enter multiposition valve in discharge opeing metering system (50) a distribution port be connected; There is a through hole at the center of described electromagnetic mixing apparatus, the internal diameter of through hole is greater than the external diameter that enters discharging tube (13) of titration cell (10), electromagnetic mixing apparatus is fixed on the bottom in fastening framework (40) in described retention mechanism, and the discharging tube (13) that enters of titration cell is connected with the pipeline (44) that enters discharge opeing metering system through the through hole at electromagnetic mixing apparatus center from the top of electromagnetic mixing apparatus.

2. automatic titration device according to claim 1, is characterized in that: the bottom (12) of described titration cell (10) is funnel type.