CN2288442Y - Automatic detector for phosphate content in water - Google Patents

Abstract

The utility model relates to an automatic detector for phosphate content in water, which utilizes the accepted electric titration with higher accuracy to carry out intermittent analysis or continuous analysis of phosphate content in water. The utility model is composed of a water sample pretreatment device, a chemical adding device, a detection pool, a central data processing system and a control device, wherein, the upper art of the detection pool is provided with an ion selective electrode and a reference electrode; the detection pool is connected with the outlet of an overflow device through a pipeline electromagnetic valve and a filter; the other outlet of the overflow device enters a drainage tank; the chemical adding electromagnetic valve is arranged on the upper part of the detection pool; the bottom of a reagent box is connected with the microcontroller in the control device through a liquid level sensor. The utility model has the characteristics of simpler structure, higher measuring precision and low maintenance and repair cost.

Description

Phosphate content automatic detection device in a kind of water

The utility model relates to the device of phosphate (orthophosphate) content in a kind of detection water, particularly relates to the automatic detection device of phosphate content in the on-line monitoring boiler water.

The device of phosphate (orthophosphate) content all adopts spectrophotometric method in the known detection water, promptly forms yellow phosphovanadomolybdic acid with molybdate and metavanadate in the phosphatic acid medium in the water sample, and its absorbance is measured in the colour developing back.Or phosphate generates molybdophosphate with molybdate in acid medium, is reduced into the phosphorus molybdenum blue with reductive agent again, and its absorbance is measured in the colour developing back, and absorbance is converted into the phosphate actual content.This is that figure is, that is that all right is ripe in various aspects of performance such as sensitivity, selectivity, stability, life-spans for the ion-selective electrode that can directly measure phosphate in the water (phosphate radical), does not still have commercial electrode supply.And adopt spectrophotometric method to detect phosphate content in the water, and general 2～4 minutes of reaction time, need to add three kinds of reagent, need use " blank " and " full scale " two kinds of standard water samples during verification.

Adopt the representative products of this principle that homemade GDL-03 type phosphate radical automatic analyzer, 2359 types of U.S. HACB company etc. are arranged.

Also have several type products, product as homemade DY9010 type and French Polymetron company, though idiographic flow has adopted flow injection analysis, its reaction mechanism remains classical phosphorus molybdenum vanadium Huang or phosphorus molybdenum blue spectrophotometric method, technical indicator does not improve yet, the response time of some imported product will be more than 10 minutes, and structure is also very complicated, maintenance difficult.

The automatic detection device of the phosphate content of known employing spectrophotometric method, the adding and the course of reaction of need control plurality of reagents, standard specimen, the reaction time is long, the consumption of reagent is bigger, resultant of reaction easily pollutes cuvette, and the cuvette after the pollution is difficult to clean, and causes zero point drift.The drift of photo-translating system self is also relatively more serious, will adopt measures such as reference cuvette and reference photoelectric cell to stablize its operating characteristic usually, and structure is complicated more, and Maintenance and Repair expense and workload are all bigger.

Similar with the method that detects water mesosilicic acid radical content, the method of using spectrophotometric method to detect phosphate content in the water also has an important disadvantages, it is exactly the heteropoly acid that phosphate and molybdate generate, also have two kinds of isomeride of α type and β type, wherein the absorbance of β type is more much higher than α type, is again unsettled, constantly transforms to the α type, the ratio of these two kinds of isomeride and conversion rate are finally to the influence of total absorbance, and causing in use, the instability and the error of reading strengthen.

The purpose of this utility model provides a kind of higher potentiometric titration of generally acknowledged precision of utilizing and phosphate content in the water is carried out the novel phosphate content automatic detection device of intermittently analyzing or analyzing continuously.It has automatic detection, and precision is higher, and is relatively simple for structure, the characteristics that Maintenance and Repair expense and workload are less.

The purpose of this utility model is achieved by the following scheme, it is by the water sample pretreatment unit, chemicals dosing plant, detection cell, central data processing system and control device are formed, it is characterized in that: ion-selective electrode (13) and contrast electrode (14) are equipped with in detection cell (9) top, detection cell is by pipeline electromagnetic valve (5), filtrator (28) is connected with the outlet (4) of overflow device (2), another outlet of overflow device is connected with inlet variable valve (1), run-down pipe (3) also is housed in the overflow device (2), arrive rhone (8) with pipeline connection, electrodes selective (13) is connected with high resistant converter (20) in the control device with contrast electrode (14), reagent box (16), by pipeline and flowmeter (17), dosing solenoid valve (18) is communicated with detection cell (9), dosing solenoid valve (18) is contained in detection cell (9) top, the reagent box bottom is connected with microcontroller (22) in the control device by liquid level sensor (19), flowmeter (17) also is connected with microcontroller (22), and drain solenoid valve (11) also is equipped with in the detection cell bottom.Going between water regulating valve (1) and the overflow device (2) temperature sensor (6) is housed.Mechanical stirrer (15) is equipped with in detection cell (9) upper end.Reagent box (16) is installed in highest point in the device.Central data processing system and control device are made up of high resistant converter (20), A/D converter (21), microcontroller (MCU) (22), special-purpose peripheral chip (23), display (24), printer (25), output circuit (26) and pad (27).The utility model can also adopt following scheme to realize, ion-selective electrode (13) and contrast electrode (14) are housed in the circulative detecting pool (31), two electrodes all are connected with high resistant converter (20) in the control device, detection cell one end is connected with the outlet (4) of reagent box (16) and overflow device (2) respectively after being connected with time-delay reacting pipe (30) again, another outlet of detection cell is communicated with rhone (8), run-down pipe (3) is housed in the overflow device to be communicated with rhone (8), the outlet of overflow device bottom is connected with the inlet variable valve, between time-delay reacting pipe (30) and the overflow device outlet (4) filtrator (28) and pipeline electromagnetic valve (5) are housed, reagent box (16) bottom is equipped with liquid level sensor (19) and is connected with microcontroller (22) in the control device.Between reagent box (16) outlet and the time-delay reacting pipe (30) dosing pump (29) is housed.

The utility model has the advantages that, simple in structure, to measure accurately, error rate is little, and measurement result is stable, and the reagent consumption is few, and the Maintenance and Repair expense is low, is convenient to generally apply.

Below in conjunction with drawings and Examples the utility model is described in further detail.

Fig. 1 is the utility model surface structure synoptic diagram.

Fig. 2 is the utility model parts catenation principle figure.

Fig. 3 is the another kind of parts catenation principle of the utility model figure.

Fig. 4 is another parts catenation principle figure of the utility model.

The concentration curve of reagent in pure water that Fig. 5 demonstrates for the represented connected mode of Fig. 3.

Fig. 6 is the potential change curve that the utility model intermediate ion electrodes selective and contrast electrode record.

The concentration curve of reagent in pure water that Fig. 7 demonstrates for the represented connected mode of Fig. 4.

1 is the inlet variable valve among the figure, and 2 is overflow device, and 3 is run-down pipe, 4 are the overflow device outlet, and 5 is solenoid valve, and 6 is temperature sensor, 7 is water flow sensing unit, and 8 is rhone, and 9 is detection cell, 10 is run-down pipe, and 11 is drain solenoid valve, and 12 is level sensor, 13 is ion-selective electrode, and 14 is contrast electrode, and 15 is mechanical stirrer, 16 is reagent box, and 17 is flowmeter, and 18 are the dosing solenoid valve, 19 is liquid level sensor, and 20 is the high resistant converter, and 21 is A/D converter, 22 is microcontroller (MCU), and 23 is special-purpose peripheral chip, and 24 is display, 25 is printer, 26 is output circuit, and 27 is pad, and 28 is filtrator, 29 is dosing pump, 30 are the time-delay reacting pipe, and 31 is circulative detecting pool, and 32 for being the water sample pump, 33 is cabinet, 34 is the multiple power supplies of each several part power supply in the machine, and 35 is the standard water sample case of demarcating usefulness automatically, and 36 is standard water sample solenoid valve for sampling.

But in the utility model all parts can outsourcing, external coordination or in all processing and manufacturings of general instrument plant, assembling gets final product with reference to accompanying drawing after getting all parts ready.

Embodiment 1: what the embodiment 1 that Fig. 2 represents used is the analytic approach at intermittence, the water sample pretreatment system is by the water sample variable valve (1) that enters the mouth, overflow device (2), solenoid valve (5) and rhone (8) are formed, water sample inlet variable valve (1) is in order to regulate the water sample flow, the outlet of variable valve (1) is connected with overflow device (2) bottom, run-down pipe (3) is equipped with at the middle part of overflow device (2), lead to rhone (8), the outlet (4) of overflow device (2) bottom is connected with the inlet of solenoid valve (5) through filtrator (28), water sample is entered by the overflow device bottom during use, major part drains into rhone (8) through run-down pipe (3), and small amount of water sample is exported by overflow device, filtrator flow to the inlet of solenoid valve (5).Intermittently the used detection cell (9) of analytic approach is a garden cup-shaped receptacle, the top of detection cell (9) is received in the outlet of solenoid valve (5), detection cell 99) run-down pipe (10) also is equipped with on top, the other end of run-down pipe is received rhone, drain solenoid valve (11) also is equipped with in the detection cell bottom, the drainpipe of drain solenoid valve is also received rhone, level sensor (12) is equipped with at the detection cell middle part, ion-selective electrode (13) and contrast electrode (14) also are equipped with in detection cell top, ion-selective electrode wherein can be selected silver ion selective electrode or lead ion electrodes selective for use according to the agents useful for same difference, and mechanical stirrer motor (15) also is installed in detection cell top.Medicine system is made up of reagent box (16), flowmeter (17) and dosing solenoid valve (18), reagent box (16) is installed in the highest point of this device, outlet at bottom is connected to flowmeter (17), the outlet of flowmeter (17) is connected with dosing solenoid valve (18), and the outlet of dosing solenoid valve (18) also is contained in the top of detection cell (9).Liquid level sensor (19) also is equipped with in reagent box (16) bottom, detection alarm when being used for lacking reagent.Central data processing and control system are by high resistant converter (20), A/D converter (21), microcontroller (MCU) (22), special-purpose peripheral chip (23), display (24), printer (25), output circuit (26) and pad (27) are formed, ion-selective electrode (13) and contrast electrode (14) are connected on the high resistant converter (20), the output voltage of high resistant converter (20) is delivered to microcontroller (22) after being changed by A/D converter (21), microcontroller (22) is connected to special-purpose peripheral chip (23), model be PSD3 * */4 * */5 * * programmable peripheral chip series, be used to realize ROM, SRAM, latch, programmable I/O mouth, multiple functions such as encryption, display (24), printer (25) and output circuit (26) all are connected on the I/O mouth of peripheral chip (23), output circuit 26 wherein has analog current output and two kinds of teletransmission way of outputs of numeral output, pad (27) is connected on the microcontroller 22, be used for the outgoing inspection instruction, on each I/O mouth of microcontroller (22), also be connected to each temperature sensor (6) respectively, liquid level sensor (12), (19), water flow sensing unit (7) flowmeter (17) and the driving circuit (not drawing among the figure) of controlling each solenoid valve.Display (24) is the dot matrix graphic liquid crystal display device module that keeps driver and controller in, it is under the control of microcontroller (22), the numeral of potential change trend in the analytic process being simulated demonstration and analysis result shows, all adopt Chinese character to show for various calibration operation indicatings and fault alarm content, very intuitive and convenient.The course of work of embodiment 1 is that microcontroller (22) control electromagnetic valve (5) is opened, water sample injects detection cell (9), close solenoid valve (5) after the overflow, opening water discharge valve (11), draining to level sensor (12) is closed draining valve (11) when sending signal, realize quantitative sampling, dosing solenoid valve (18) is opened then, reagent adds water sample, microcontroller (22) is constantly gathered the current potential of ion-selective electrode (13) and contrast electrode (14) output, in titration end-point, current potential is undergone mutation, and microcontroller (22) cuts out the reagent consumption that dosing solenoid valve (18) and statistic flow meter (17) record, and compares with the reagent consumption of the standard water sample that deposits microcontroller in, calculate the phosphate content in the water sample, carry out the demonstration of data simultaneously, print and output.When the unexpected overtemperature of water sample, microcontroller (22) warning shutdown automatically when cutting off the water supply sample or scarce reagent.

Embodiment 2: what Fig. 3 represented is the composition synoptic diagram of embodiment 2.Its central data processing and control system are identical so no longer repeat to draw with embodiment 1, and the water sample pretreatment system is also identical.In Fig. 3, reagent box (16) outlet is connected to one and can accurately controls the dosing pump (29) that adds dose, this dosing pump can be ram pump driven by stepper motors or the dosing pump that similarly has accurate feedback system, the outlet of dosing pump (29) is connected with the water sample pipeline, receive airtight circulative detecting pool (31) through time-delay reacting pipe (30) again, detection cell is equipped with ion-selective electrode (13) and contrast electrode (14), and rhone (8) is received in outlet.Embodiment 2 has used the higher triangle program titrimetry of precision, its course of work and principle are: the water sample flow through overflow device (2) current stabilization is constant, the reagent volume flow velocity of microcontroller (22) control dosing pump (29), make its concentration change in pure water present the pattern of an isosceles triangle, as shown in Figure 5.The phosphate in the water sample and the reagent reacting of concentration change, be equivalent to normal titration and back titration respectively once, Fig. 6 is the potential change curve that ion-selective electrode (13) and contrast electrode (14) record, two titration end-points of rise and fall have appearred on the curve, the spent time between two titration end-points, be the T among Fig. 6, be inversely proportional to the phosphate content in the water sample, microcontroller (22) is compared T with the T value of the standard water sample that deposits microcontroller in, calculate the phosphate content in the water sample, carry out demonstration, printing and the output of data simultaneously.

Embodiment 3: Fig. 4 is the composition synoptic diagram of embodiment 3.Its central data processing and control system are identical so no longer repeat to draw with embodiment 1 or embodiment 2, and the water sample pretreatment system is also identical.In Fig. 4, as different from Example 2, reagent box (16) outlet also is connected to a dosing pump (29), but this dosing pump is the dosing pump of the ram pump, electromagnetic diaphragmpump or other type that fixedly add dose, when the reagent box installation site is higher, also can use solenoid valve to carry out dosing.Because embodiment 3 has used pipeline thinner, that resistance is bigger, has increased water sample pump (32), water sample pump (32) adopts peristaltic pump usually, drives water sample and keeps flow speed stability.Identical with embodiment 2, the outlet of dosing pump (29) is connected with the water sample pipeline, receive airtight flow type through time-delay reacting pipe (30) again and detect (31), detection cell is equipped with ion-selective electrode (13) and contrast electrode (14), and rhone (8) is received in outlet.Embodiment 3 has used the injection reagent method in the advanced flowing injecting analysis technology (to be also referred to as reverse flow injection analysis, abbreviation rFIA), its course of work and principle are: water sample (here as current-carrying) flow is constant, microcontroller (22) control dosing pump (29) regularly injects the reagent of a little volume in water sample, different with embodiment 2, enforcement 3 has been used thinner, the reacting pipe that resistance is bigger (30), has higher dispersion coefficient, after reagent is injected into, along with flowing of current-carrying, axially elongated along reacting pipe, the reagent band of a dispersion of formation is when current-carrying is pure water, in the center of reagent band reagent concentration maximum, reduced successively by middle mind-set both sides concentration, promptly have the continually varying concentration gradient, Fig. 7 is this continually varying concentration gradient synoptic diagram.When containing phosphate in the current-carrying (water sample), reagent band reaction with concentration change, two titration end-points of rise and fall among Fig. 6 have also appearred resembling on the potential change curve that ion-selective electrode (13) and contrast electrode (14) record, spent time T between two titration end-points, or be injected into from reagent time of two one of them terminal points of titration end-point, or the chemical kinetic process of reagent and current-carrying, the read output signal that all can be used as microcontroller carries out computing, is converted into corresponding phosphate content.Potential change curve in embodiment 3 comes down to the concentrated expression of the various processes of Flow Injection Analysis, because Flow Injection Analysis control analysis process is well accurately reappeared this concentrated expression, measuring accuracy is also very high.Add a standard water sample case and solenoid valve in the water sample pretreatment system in these three embodiment, regularly switch, can realize automatic verification by microcontroller.

The utility model as a kind of accurately, the automatic detection device of on-line monitoring phosphate content fast, be particularly suitable for substituting known instrument product, be used for controlling the dose that adds of boiler dosing pump, realize the adding-reagent automation of water treatment in the boiler stove.

Claims (7)

1, phosphate content automatic detection device in a kind of water, it is by the water sample pretreatment unit, chemicals dosing plant, detection cell, central data processing system and control device are formed, it is characterized in that: ion-selective electrode (13) and contrast electrode (14) are equipped with in detection cell (9) top, detection cell is by pipeline electromagnetic valve (5), filtrator (28) is connected with the outlet (4) of overflow device (2), another outlet of overflow device is connected with inlet variable valve (1), run-down pipe (3) also is housed in the overflow device (2), arrive rhone (8) with pipeline connection, electrodes selective (13) is connected with high resistant converter (20) in the control device with contrast electrode (14), reagent box (16), by pipeline and flowmeter (17), dosing solenoid valve (18) is communicated with detection cell (9), dosing solenoid valve (18) is contained in detection cell (9) top, the reagent box bottom is connected with microcontroller (22) in the control device by liquid level sensor (19), flowmeter (17) also is connected with microcontroller (22), and drain solenoid valve (11) also is equipped with in the detection cell bottom.

2, phosphate content automatic detection device in a kind of water according to claim 1 is characterized in that: going between water regulating valve (1) and the surplus valve (2) temperature sensor (6) is housed.

3, phosphate content automatic detection device in a kind of water according to claim 1 is characterized in that: mechanical stirrer (15) is equipped with in detection cell (9) upper end.

4, phosphate content automatic detection device in a kind of water according to claim 1, it is characterized in that: reagent box (16) is installed in highest point in the device.

5, phosphate content automatic detection device in a kind of water according to claim 1 is characterized in that: central data processing system and control device are made up of high resistant converter (20), A/D converter (21), microcontroller (MCU) (22), special-purpose peripheral chip (23), display (24), printer (25), output circuit (26) and pad (27).

6, phosphate content automatic detection device in a kind of water, it is characterized in that: ion-selective electrode (13) and contrast electrode (14) are housed in the circulative detecting pool (31), two electrodes all are connected with high resistant converter (20) in the control device, detection cell one end is connected with the outlet (4) of reagent box (16) and overflow device (2) respectively after being connected with time-delay reacting pipe (30) again, another outlet of detection cell is communicated with rhone (8), run-down pipe (3) is housed in the overflow device to be communicated with rhone (8), the outlet of overflow device bottom is connected with the inlet variable valve, between time-delay reacting pipe (30) and the overflow device outlet (4) filtrator (28) and pipeline battery valve (5) are housed, reagent box (16) bottom is equipped with liquid level sensor (19) and is connected with microcontroller (22) in the control device.

7, phosphate content automatic detection device in a kind of water according to claim 6 is characterized in that: between reagent box (16) outlet and the time-delay reacting pipe (30) dosing pump (29) is housed.

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