CN2157520Y

CN2157520Y - Microcoulomb titration cell

Info

Publication number: CN2157520Y
Application number: CN 93215743
Authority: CN
Inventors: 张金锐; 魏月萍
Original assignee: Sinopec Research Institute of Petroleum Processing
Current assignee: Sinopec Research Institute of Petroleum Processing
Priority date: 1993-06-15
Filing date: 1993-06-15
Publication date: 1994-02-23
Anticipated expiration: 2003-06-15

Abstract

The utility model relates to a micro-coulomb titration cell used for the micro-coulomb titration analysis, comprising a cell body, a cell cover, a pair of electrolytic electrodes, a pair of measuring electrodes, a drying tube, a sample feeding tube, a magnetic core stirrer, etc. The electrolytic electrode is formed by a platinum wire and a platinum net which are in spot welding, and an ion exchanger membrane which has large area is arranged between the platinum wire and the platinum net. Each of the measuring electrode comprises a pair of platinum wires, and platinum sheets are mutually and parallelly arranged under each platinum wire. Various components arranged on the titration cell are milled by polytetrafluorethylene materials. The utility model can be used for various micro-coulomb analysis for gases, liquid, and solid samples, having the advantages of low impedance, good electrode isolation, high stability, easy cleanness of the components, easy replacement of the components, good combination performance, and good sealing performance.

Description

Microcoulomb titration cell

The utility model is a kind of titration cell that microcoulomb is analyzed that is used for, and belongs to the technical field of coulometric analysis in the physico-chemical analysis.

Microcoulometry is sensitive faster, the analytical approach accurately and rapidly of development in recent years, and it can do the element such as sulphur, nitrogen, chlorine, water in the organic and mineral compound of petroleum products and other or the constant or the microdetermination of material.Microcoulomb is analyzed used equipment and is generally Microcoulomb instrument, titration cell and auxiliary device that some are necessary.According to analysis purpose thing difference, titration cell also has different structures.The effect of titration cell is that the titrant in measured matter and the electrolytic solution is reacted in the pond.Titration cell all is equipped with two pairs of electrodes, promptly a pair of electrolysis electrode and a pair of potential electrode.The structure of electrolysis electrode and relative position be different and variant according to measured matter then.Between titrant and measured matter, should have fast and contact fully, and form uniform diffusion layer, thus more than carry out the stirring of adjustable rotating speed with the stirring rod in the rotary magnet drive titration cell.On identical titration cell, the inlet and the titration solvent of the structure of electrode, material, titration cell changed, promptly can be used for different chemical reactions and different element determinations.The general structure of relevant microcoulomb analysis and titration cell can be referring to the relevant chapters and sections in " microcoulomb analysis principle and application " (Zhang Jinrui writes, and petroleum industry publishing house publishes, 1984) book.

Titration cell of the present utility model is mainly used in and measures gas, liquid, reaches liquid water content and bromine valency in the liquid petroleum product and the sulfur content in the heavy crude product in the solid sample, but to the structure of electrode and electrolytic solution form do change slightly after, also can be used for the mensuration of other samples and element.

Equipment with the micro-coulometric determination liquid water content, the home and abroad all has commercial instrument, CA-05 type Moisture Meter as Mitsubishi chemical company, Japan's flat natural pond AQ-6 type determination of moisture device and series of products thereof, the model Microcoulomb instruments such as YS-2A, YS-3 that domestic Jiangsu Electrical Analysis Instrument Factory produces, and the WS-1 type micro-water analyzer of Shandong Zibo radio one factory production etc.Among the ministerial standard SY2508-83 of China PetroChemical Corporation " adjuvant and doped lubricating oil aquametry (coulometry) " titration cell also had concrete requirement.EP0390727A2 also discloses a kind of titration cell of micro-coulometric determination moisture.Though the above used titration cell of instrument respectively has its characteristics, also has weak point, be mostly to adopt the ground glass interface as assembly, the active level of assembling is poor; Isolate not easy cleaning and replacing between anode chamber and cathode chamber with the ground glass chip; Potential electrode adopts contact or taenidium formula more, and contact area is little, poor sensitivity; The application of sample mouth adopts the logical input mode of side, in the difficult directly adding of the sample titration solvent or the like.These problems all have much room for improvement to guarantee sensitivity that microcoulomb analyzes, characteristics fast and accurately.

The purpose of this utility model just is in order to overcome the weak point that above existing titration cell exists, and proposes a kind of than the prior art titration cell of rational structure and parts connected mode more.

The structure in the utility model micro-coulometric titration pond referring to accompanying drawing 1 to accompanying drawing 7.

The structure in existing accompanying drawings the utility model micro-coulometric titration pond.Fig. 1 is total figure of titration cell, and Fig. 2 is the top view of teflon Chi Gai, has shown each plug-in mounting position component, and Fig. 3 is an electrolysis cathode, and Fig. 4 is an electrolytic anode, and Fig. 5 is that potential electrode is right, and Fig. 6 is a drying tube, and Fig. 7 is the sample introduction pipe.

Pond body 3 among Fig. 1 is cup-shaped glass garden tubes of one flat, flat mouthful, and nozzle turns up to be had along also process frosted processing levelling, and contact plane is preferably arranged, and the inboard of pond body 3 has constituted the anode chamber of titration cell.Pond lid 2 is teflon garden sheets that a thickness is 25mm, and its upper diameter is identical with the nozzle external diameter of pond body 3, and lower diameter is identical with the internal diameter of pond body 3.Pond lid 2 can closely be filled on the bead of pond body 3.The mode of on pond lid 2, inserting by means of screw thread or ground be fixed with potential electrode to 1, electrolytic anode 5, electrolysis cathode 9, drying tube 13(dot), sample introduction pipe 10, and grinding port plug 14.Cored teflon stirrer 4 by the rotary magnet driven rotary, mixes rapidly to guarantee sample and electrolytic solution when titration.

The pond of Fig. 2 is covered 2 top views and is shown plug-in mounting component locations in the above.The 15th, potential electrode is to 1 ground jack, the 16th, the ground jack of drying tube 13, the 17th, the anti-ground jack of electrolytic anode 5 is (big down little, insert from bottom to top), the 18th, the jack of electrolysis cathode 9, the 19th, the ground jack of grinding port plug 14, the 20th, the interface holes of sample introduction pipe 10, car has internal thread in the hole.

Electrolysis cathode among Fig. 3 by cathode sleeve 7, negative electrode turncap 8, negative electrode spiral cover 11, negative electrode platinum filament and platinum guaze 9, and the protection negative electrode parts such as glass bushing 12 constitute.Except that platinum filament, platinum guaze and the glass bushing 12 of negative electrode 9,7,8,11 all make with the polytetrafluoroethylmaterial material car, and internal thread is arranged at the top of cathode sleeve 7, and the external thread of mat negative electrode spiral cover 11 screws in glass bushing 12 in the cathode sleeve 7 together with negative electrode 9.External thread is arranged at the bottom of cathode sleeve 7, amberplex 6 is pressed abd fixed on the exit, lower end of cathode sleeve 7 with negative electrode turncap 8.

Electrolytic anode 5 among Fig. 4 is basic identical with platinum filament, the platinum guaze structure of electrolysis cathode 9; all be after protecting with glass bushing by the platinum filament of diameter 0.8mm; the bottom sintering sealing of glass bushing; reserve one section platinum filament spot welding lopping, be welded into net with the thin platinum filament point of diameter 0.03～0.05mm again on the circle and form.Bend at an angle of 90 by glass bushing 21 protections and in the bottom outside of anode platinum filament 5, makes the platinum guaze of negative electrode 9 be symmetry and parallel position up and down with the platinum guaze of anode 5.The top of glass bushing 21 is expanded into up-small and down-big anti-ground, so that can instead from bottom to top insert in the anti-ground jack 17 of anode of pond lid 2.

Electrolytic anode 5 all is connected with Microcoulomb instrument through lead with the top of electrolysis cathode 9.

Potential electrode among Fig. 5 to 1 by two platinum filaments and below platinum filament, respectively be welded with a little platinized platinum and constitute.Thick 0.15～the 0.20mm of platinized platinum, area are 5 * 7mm, two positions that are parallel symmetry.In potential electrode also there is glass bushing 22 1 outside, its top also is expanded into ground, can insert in the electrode pair jack 15 on the pond lid 2 and fixes.The top that potential electrode is right also is connected to two leads and links to each other with Microcoulomb instrument.

Fig. 6 is the signal of drying tube 13.The effect of drying tube 13 is to make the pressure in the titration cell keep balance by drying tube 13 and environmental pressure, but the moisture in the environment can not enter in the titration cell because of the obstruct of drying agent, has eliminated the interference to analyzing.Drying tube is designed to inverted " U " shape by the elbow at two 90 ° of angles, is inserted in the drying tube jack 16 on the pond lid 2 with ground, and the other end is also with grinding port plug pipe and environmental communication.Such design can make the center of gravity of drying tube reduce, not frangibility.

The left side of Fig. 7 is the signal of sample introduction pipe 10, and it is the teflon heavy wall short tube that an internal diameter is about 10mm.The outer is arranged at the pipe top, and the outer sidecar of pipe has screw thread, can screw in the sample introduction interface tube hole 20 of pond lid 2.One circle platform is arranged in the bottom of interface holes 20.The silicon rubber pad that will advance analytic sample syringe needle puncture is placed on earlier on the bottom platform circle in the interface holes 20, with hand sample introduction pipe 10 is screwed again.So just make the silicon rubber pad compacted in the bottom of sample introduction pipe 10.After the fluid analysis sample can extract with syringe, injection needle is penetrated the silicon rubber pad and directly inject in the electrolytic solution.As analytic sample is gas, can use the gas sampling pipe 23 on Fig. 7 right side, and it is the heavy wall glass tube of an about 2mm of the about 4mm internal diameter of external diameter, the drawing-down of exit, lower end, and the upper end is sintering one ground then, can insert in the replacing electrolytic solution grinding port plug jack 19 of pond lid 2.Gas sampling pipe 23 tops are connected with analytic sample gas, branch gassing sample are directly fed in the electrolytic solution analyze.As analytical sample is solid, then needs to increase the equipment for gasification of a solid sample, makes the solid sample gasification after sample introduction pipe 23 enters in the electrolytic solution of electrolytic cell.

Compare with existing micro-coulometric titration pond, the utility model has the advantages that:

1. ground binding parts all adopt the interior ground of glass and the outer grinding port of teflon to join, because the teflon material itself has certain flexibility and lubricity, ground is difficult for the phenomenon that cementation is not opened takes place, and breakage rate is little, the assembling performance is good, and sealing property might as well.

2. the platinum filament one glass weldering knot parts except that necessity adopt the glass material, and assembling parts uses the teflon material to process as far as possible, and the screw thread good seal performance is more solid and reliable after improving machining precision.

3. electrolysis cathode is the cathode chamber that is made of cathode sleeve 7, negative electrode turncap 8 and ionic membrane 6.Ionic membrane is installed easily, is convenient to don't wash and more renew film.The bore of cathode sleeve 7 and negative electrode turncap 8 is big, and the area of amberplex 6 is bigger, has guaranteed the migration of ion.

4. electrolysis electrode adopts gauze platinum electrode to replace the platinum electrode of using always in the prior art, potential electrode adopts the platinized platinum electrode to replace contact point electrode commonly used, so all increase the contact area of electrode and reactant, also correspondingly improved the sensitivity that microcoulomb is analyzed.

Claims

1, a kind of by pond body, Chi Gai, electrolysis electrode to and potential electrode equity parts constitute be used for the titration cell that micro-coulometric titration is analyzed, it is characterized in that:

(1) electrolysis cathode is to be made of cathode sleeve 7, negative electrode turncap 8, the negative electrode spiral cover 11 of teflon material and the negative electrode platinum filament platinum guaze of being protected by glass bushing 12 9, and amberplex 6 is compressed and be fixed on the exit, lower end of cathode sleeve 7 by ribbed cathode sleeve 7 of car and negative electrode turncap 8;

(2) the electrode platinum guaze of electrolysis cathode 9 and electrolytic anode 5 becomes laterally zygomorphic parallel position;

(3) potential electrode is respectively welded a platinized platinum parallel to each other and symmetrical placement to 1 by two platinum filaments and in the platinum filament lower end and is constituted.

2, according to the said titration cell of claim 1, it is characterized in that having on the teflon pond lid 2 the liquid sample introduction interface tube hole 20 of band rib-loop, the silicon rubber pad of sample introduction being used by sample introduction pipe 10 is pressed on the bottom platform of interface holes 20.

3, according to the said titration cell of claim 1, it is characterized in that on pond lid 2, drying tube jack 16 being arranged, the drying tube 13 that is inversion " U " shape is connected with titration cell with ground.