CN2157516Y

CN2157516Y - Carbonifying conversion tester

Info

Publication number: CN2157516Y
Application number: CN 93212330
Authority: CN
Inventors: 王贵云; 李济和
Original assignee: SODA PRODUCE INDUSTRY INST MINISTRY OF CHEMICAL INDUSTRY
Current assignee: SODA PRODUCE INDUSTRY INST MINISTRY OF CHEMICAL INDUSTRY
Priority date: 1993-05-07
Filing date: 1993-05-07
Publication date: 1994-02-23
Anticipated expiration: 2003-05-07

Abstract

The utility model relates to a tester for carbonifying conversion rate, which is used when sodium bicarbonate is prepared. The utility model comprises the tester, a display, etc., wherein, the tester which is composed of a sodion selective electrode with low internal resistance and a reference electrode is arranged in an alkali tank for liquid taken out; an electrode signal obtained by test to records the instantaneous carbonifying conversion rate with an automatic recorder after impedance transformation, the operational amplification and the amplification of inverted input and to continuously and automatically detect the value of the instantaneous carbonifying conversion rate in a digital display mode. Thus, an operator can regulate and control the carbonifying operation; the tester is particularly suitable for the ammonia-soda process; the measuring indication error of the utility model is less than +/-1%24; the hourly drift is less than +/-1%.

Description

Carbonifying conversion tester

It is that raw material is produced NaHCO with sodium chloride etc. that the utility model relates to a kind of ₃Method in measure the instrument of carbonization conversion ratio, the conversion ratio that is particularly useful in the ammonia-soda process reparation technology detects.

Carbonization conversion ratio (UNa) is to be converted into NaHCO in the carbonization process ₃The NaCl amount of crystallization accounts for the percentage of NaCl total amount in the ammonial brine, the method of measuring at present UNa has still all been continued to use the chemical analysis that institute uses always since Sol dimension system alkaline process comes out before more than 100 year, promptly by the CNH in sampling titrimetry ammonial brine and the carbonization taking-up liquid ₃, Tcl ^-, SO ₄ ^2-Content by formula calculates and predicts, thus take a lot of work, time-consuming, analysis cost is high, particularly instruct to produce to lag behind; " soda ash engineering " (the 724th page of Chemical Industry Press's in July, 1992 second edition) reported a kind of PIM-791 type sodium ion analyzer and can be used for measuring UNa, the electrode pair that this meter adopts high internal resistance (100M Ω) glass-film Na ion-selective electrode and contrast electrode to form reaches the high input impedance operational amplifier of the band temperature compensation that electrode pair therewith is fitted together, this electrode pair must be inserted in the special electrode cell, in order to avoid electrode pair is subjected to NaHCO ₃Washing away of crystallization, and overcome the influence of streaming potential difference, the electric potential signal that produces by electrode pair could long-distance transmissions after impedance conversion becomes the low-resistance signal on self-recorder, write down out Na ion concentration value, then with the taking-up liquid that records with chemical analysis in the Tcl value, predict UNa by searching special carbonization conversion ratio conversion chart, this method exists formality miscellaneous equally, instruct disadvantages such as producing hysteresis, particularly because this Na ion-selective electrode internal resistance height, the electric potential signal that takes out is ability long-distance transmissions after impedance conversion becomes the low-resistance signal earlier, this just requires this amplifier and this electrode pair are fitted together, and this needs pair amplifier to give strict sealed insulation, otherwise, insulation has reduction will cause the serious drift of electric potential signal slightly, and to take out near extremely difficult the accomplishing of height insulation that keeps long-term the liquid caustic soda groove, in addition, when being connected to this amp.in, this high resistant Na ion-selective electrode also can cause the duty of amplifier two ends seriously asymmetric, ambient room temperature changes slightly and can cause the big drift of its output signal, therefore, amplifier must have temperature-compensation circuit, based on above-mentioned weak point, this sodium ion analyzer lacks industrial applicibility, fail to promote practicality, the present industrial aforesaid chemical analysis of still all continuing to use always.

The purpose of this utility model be to overcome above-mentioned the deficiencies in the prior art part and provide a kind of measuring accuracy height, good stability, highly sensitive, installation, maintenance, easy to use, can show and write down instantaneous carbonization conversion value continuously automatically in time to instruct the carbonization conversion ratio detector of carbonization operation.

The purpose of this utility model can reach by following technical scheme: this carbonization conversion ratio detector comprises detecting device and protective cover and display, detecting device is that low internal resistance sodium selective electrode and the contrast electrode of 2000 Ω～10M Ω formed by internal resistance, display comprises high input impedance operational amplifier and the self-recorder that contains phase inverter, detecting device and protective cover thereof immerse to be desired in the carbon determination taking-up liquid, the electrode potential that is produced is linear with the logarithm that takes out the Na ion activity in the liquid, this electrode potential signal is through impedance conversion, and computing zooms into Na ion concentration signal and zooms into the conversion ratio signal through the phase inverter computing again and write down out the UNa value by self-recorder; After using low internal resistance Na ion-selective electrode, electrode signal can directly be transferred on the operational amplifier that contains phase inverter of long distance detecting device, in addition, when low internal resistance Na ion-selective electrode is connected to this amplifier, amplifier two ends are in the low-resistance duty together, and its output voltage is difficult for changing and drift with ambient room temperature, and the stability of display is high, under normal production conditions, the Tcl in the ammonial brine ^-, CNH ₃With the SO that takes out in the liquid ₄ ^2-Substantially constant, press UNa(%)={ 1-1/ (K) ［ Na ］ (taking-up) } * 100, K=Tcl ^-(taking-up)-a+b, a=CNH ₃(ammonial brine) * Tcl ^-(taking-up)/Tcl ^-(ammonial brine), b=SO ₄ ^2-(taking-up), UNa is only relevant with the Na ion concentration in the taking-up liquid, and promptly the Na ion concentration is lower, and UNa is higher, and the phase inverter in the operational amplifier zooms into corresponding UNa signal with the input of Na ion concentration signal inversion; The detector guard cover is coaxial by dress with detecting device; it immerses taking-up liquid bath end is uncovered; this opening end end should exceed the end of detecting device (electrode pair) slightly; have on the cover wall that takes out liquid liquid stream side dorsad of this protective cover and take out the liquid pod apertures; take out liquid liquid stream to the washing away of electrode to slow down carbonization, improve the serviceable life of detecting device and overcome the influence of streaming potential difference.

The utility model purpose also can reach by following measure: can connect digital voltmeter behind the amplifier of display the UNa signal is directly demonstrated the UNa value with digital form, the operator can estimate the UNa value at any time, take this, can in time regulate and control the carbonization operation and make it be in optimum condition;

The utility model compared with prior art has following advantage:

1. detect easy, reliable, timely, (display generally can be installed in the post operation chamber) can directly predict instantaneous UNa value continuously from the display of long distance detecting device, take this, can in time regulate and control carbonization operation to improve the crude salt utilization factor, reduce the salt consumption, to be that excellent product, stable and high yields provide reliably, detection means timely;

2. instrumental sensitivity height can show the UNa value that has changed in the several seconds,

3. stability of instrument is good, and actual measurement shows: 24 hours drift＜± 0.5～± 0.1%;

4. accuracy of instrument; With chemical analysis ratio, its error of indication＜± 0.6～± 1%;

5. the instrument installation and maintenance are easy, and the life-span is long, and detecting device can directly immerse and take out in the liquid caustic soda groove, and the several months on probation does not see the influence that scabs;

6. can be the enforcement that the carbonization automatic operation provides signal, promotes the carbonization automatic operation.

The drawing of accompanying drawing is described as follows:

Fig. 1 detector structural representation.

Fig. 2 contains the high input impedance operational amplifier circuit theory diagrams of phase inverter.

The utility model is described in further detail below in conjunction with accompanying drawing:

With reference to Fig. 1: detector (1) and protective cover (2) thereof immerse the electrode signal that produces after carbonization is taken out in the liquid caustic soda groove and are transferred in the display (8) that is installed in the post operation chamber through wherein the high input impedance operational amplifier that contains phase inverter (5) impedance transformation, operation amplifier, in digital voltmeter (6) demonstration UNa value through shielding line (3); in the corresponding UNa value of self-recorder (7) record, D.C. regulated power supply (4) provides voltage-stabilized power supply for amplifier simultaneously.

With reference to Fig. 2: A₁The follower that improves amplifier input impedance, A₂Be phase inverter, A₃Be amplifier, its multiplication factor K₁＝（W ₁＋R ₅）／4；R ₆、R ₇、R ₈、R ₉、R ₁₀、R ₁₁Jointly consist of the slope adjustment circuit of instrument with W, after instrument assembles, take out standard sample calibrating instrument that liquid forms, namely with the simulation carbonization: the UNa changing value with slope adjustment circuit adjustment instrument display makes it consistent with the UNa changing value of standard sample, and then position adjusting with the location regulating circuit, make UNa value in the standard sample and instrument display value identical; Rc consists of filter circuit with C and exchanges interference to filter, and improves stability of instrument.

Embodiment 1:

Press Fig. 1, Fig. 2 and implement, detecting device is by 4M Ω glass-film Na ion-selective electrode and F ₄₀Fixedly contrast electrode is formed, and obtains following effect: 24 hours drift＜± 0.7%, the error of indication＜± 0.8%, 3～5 seconds response times;

Embodiment 2:

Press Fig. 1, Fig. 2 and implement, detecting device is made up of 2000 Ω pottery Na ion-selective electrode and calomel reference electrode, obtains following effect, 24 hours drift＜± 0.5%, the error of indication＜± 0.6%, 2～3 seconds response times;

Embodiment 3:

Press Fig. 1, Fig. 2 and implement, detecting device is made up of 10M Ω Na ion-selective electrode and Ag--Agcl contrast electrode, obtains following effect: 24 hours drift＜± 1%, the error of indication＜± 1%, 6～8 seconds response times.

Claims

1, a kind of carbonization conversion ratio detector; contain self-recorder; of the present utility model being characterised in that comprises: one by the sodium selective electrode of 2000 Ω～10M Ω internal resistance and the detecting device that contrast electrode is formed; a display and one the one detector guard cover that end is uncovered that contains the high input impedance operational amplifier of phase inverter has the liquid of taking-up pod apertures on the cover wall that takes out liquid liquid stream side dorsad of this protective cover.

2, detector according to claim 1 is characterized in that display contains digital voltmeter.