Background technology
Organic carbon refers in rock the carbon be present in organism.It does not comprise the carbon in carbonatite, graphite.The usual number percent with rock quality represents.In principle, organic in rock amount also should comprise the total amount of all elements be present in organic matter such as H, O, N, S
Total Organic Carbon (TOC) total organic carbon refers to the total amount of dissolubility and suspension organism carbon containing in water body.The kind of Organic substance in water is a lot, all can't carry out separation qualification at present.Often represent with " TOC ".TOC is the overall target of a rapid verification, and it represents in water containing organic total amount with the quantity of carbon.But because it can not reflect kind and the composition of Organic substance in water, the different pollution effects that the total organic carbon that total amount is identical causes thus can not be reflected.Usually used as the important evidence evaluating water body organism pollution level.
When the component of certain industrial waste water is relatively stable, the emission standard of regulation TOC can be carried out according to the total organic carbon of waste water with the relativity between biochemical oxygen demand and chemical oxygen demand (COD), greatly can improve the efficiency of monitoring like this.During mensuration, first by catalytic combustion or wet oxidation method, the organic carbon in sample is all converted into carbon dioxide, the carbon dioxide of generation can directly be measured with infrared detector, also can be converted into methane, measure with flame ionization ditector, then carbon dioxide content is converted to carbon content.Refer under 900 DEG C of high temperature, make catalyzer with platinum, make water sample oxidizing fire, the increment of CO2 in mensurated gas composition, thus determine carbon content total in water sample, represent the overall target of total amount of organic in water sample.Because the mensuration of TOC adopts high-temp combustion, therefore organism all can be oxidized, it more can the organic total amount of direct representation than BOD5 or COD.Therefore the degree evaluating Organic Pollution in water body is often used to.
In prior art, application number is that the application for a patent for invention of CN201110393659.4 discloses a kind of infrared TOC analyser, it is characterized in that, comprises total carbon measuring system, inorganic carbon measuring system, data handling system, control system composition; Described control system controls total carbon measuring system, inorganic carbon measuring system process, and output signal is passed to described data handling system.But, in the environment being only concerned about total carbon measurement result, when utilizing its long-term work, because the stability of Instrument sensor limits, the true and reliable property of data cannot be guaranteed.Especially in practice, it use inorganic carbon measuring system, this measuring system and organic measuring system work together and can make that TOC analyser is as easy as rolling off a log to be polluted, and then cause the inaccurate probability of DATA REASONING larger.
Summary of the invention
In order to overcome the above-mentioned weak point of prior art, the invention provides a kind of detection method of online TOC monitor, this online TOC monitor comprises the first total carbon measuring system, the second total carbon measuring system, data handling system, network transmission system, purging system, control system composition, described control system controls total carbon measuring system, first total carbon measuring system and the second total carbon measuring system all detect for TOC, and the first total carbon measuring system is lower than the measuring accuracy of the second total carbon measuring system, this detection method comprises: when data handling system judges that the measured value of the first total carbon measuring system is greater than predetermined threshold value, start the second total carbon measuring system to measure, utilize purging system to clean the first total carbon measuring system simultaneously, and when the measured value of the second total carbon measuring system still exceeds predetermined threshold value, the first total carbon measuring system is again utilized to measure, when the measured value of this first total carbon measuring system and the second total carbon measuring system all exceedes predetermined threshold, again the measured value that the first total carbon measuring system is measured for the last time is transmitted by network transmission system.
Further, described total carbon measuring system comprises: temperature probe, auto injection unit, heating flame unit, optical measurement unit.
Further, described auto injection unit comprises: gas circuit travel mechanism, water sample bindiny mechanism, crucible combustion mechanism; Described heating flame unit produces circuit by HF voltage, high-voltage electrical tube, high-frequency electromagnetic control circuit, high-frequency heating spiral pipe, quartz ampoule firing chamber are formed; Prepurge unit is by pressure control mechanism, firing chamber, form except water pipe, adsorption tube, optical absorption pipe, air valve, connecting line; Optical measurement unit is made up of infrared light supply, optical absorption pipe, infrared receiver sensor, photoelectric conversion circuit, signal modulating system, signal amplification circuit.
Further, described data handling system comprises signal transacting and amplifying circuit, analog to digital conversion circuit, single chip circuit.
Further, described gas circuit travel mechanism is made up of air valve, mobile cylinder, air cylinder support and connecting line; Described water sample bindiny mechanism is made up of water sample mouth, solenoid valve, water sample pump, water sample walkthrough, connecting line; Burning crucible mechanism is made up of the cup-shaped crucible of platinum material, crucible bracket, rising cylinder.
Further, described heating flame unit is combustion furnace.
Further, described combustion furnace comprises: heater block and flame tube, and described heater block is heating wire, and described flame tube is quartz glass.
Further, when measured value does not exceed predetermined threshold, then purging system removes the impurity of impurity and the rear attachment of combustion furnace burning deposited in the pipeline of online TOC monitor.
Beneficial effect of the present invention is as follows: can be conducive to system and work for a long time online, continuously, and improves the accuracy of remote monitoring end data collection.
Embodiment
As shown in Figure 1, online TOC monitor comprises the first total carbon measuring system, the second total carbon measuring system, data handling system, network transmission system, purging system, control system composition, described control system controls total carbon measuring system, first total carbon measuring system and the second total carbon measuring system all detect for TOC, and the first total carbon measuring system is lower than the measuring accuracy of the second total carbon measuring system, this detection method comprises: when data handling system judges that the measured value of the first total carbon measuring system is greater than predetermined threshold value, start the second total carbon measuring system to measure, utilize purging system to clean the first total carbon measuring system simultaneously, and when the measured value of the second total carbon measuring system still exceeds predetermined threshold value, the first total carbon measuring system is again utilized to measure, when the measured value of this first total carbon measuring system and the second total carbon measuring system all exceedes predetermined threshold, again the measured value that the first total carbon measuring system is measured for the last time is transmitted by network transmission system.
Described total carbon measuring system includes: temperature probe, auto injection unit, heating flame unit, optical measurement unit.Wherein temperature probe is for detecting the temperature of heating flame unit, so that just detect, to improve accuracy in detection at suitable, substantially constant temperature.Auto injection unit comprises three parts, and one is gas circuit travel mechanism, and two is water sample bindiny mechanisms, and three is crucible combustion mechanisms.
Gas circuit travel mechanism is made up of air valve, mobile cylinder, air cylinder support and connecting line; Water sample bindiny mechanism is made up of water sample mouth, solenoid valve, water sample pump, the pre-heat-extraction system of water sample, connecting line; Burning crucible mechanism is made up of the cup-shaped crucible of molybdenum gold copper-base alloy, crucible bracket, rising cylinder.
Because the burning of water sample is at high temperature carried out, if sample introduction mouth and combustion system are put together, easily distortion and blocking; Consider above-mentioned factor, sampling system is determined to be designed to isolating construction, first by air-channel system promotion cylinder, sample introduction mouth is delivered to the top of crucible when starting sample introduction, the sampling pump restarting water sample connected system joins water sample in crucible, add after water sample completes, air-channel system promotes cylinder and water sample mouth is sent back to original position, by crucible bracket crucible is delivered in combustion system and burns.
The advantage of auto injection unit is: automatically complete sample introduction; Sample introduction mouth is separated with combustion cell and ensure that sample introduction mouth is indeformable, and sample introduction mouth is not easy blocking; The diameter of sample introduction mouth is larger, need not be formed vaporific during sample introduction, need not pulverize at a high speed, filter, be more conducive to organic measurement to water sample.
Heating flame unit produces circuit, high-voltage electrical tube, high-frequency electromagnetic control circuit, high-frequency heating spiral pipe, quartz ampoule firing chamber composition primarily of HF voltage.According to the amount of water sample and the frequency of temperature of combustion (1200 degree) adjustment high-frequency electromagnetic; Quartz ampoule firing chamber will ensure sealing, does not allow gas leakage.
After water sample adds crucible, control system starts high-frequency electromagnetic oven, the HF voltage produced is added on molybdenum gold crucible by spiral pipe, according to eddy effect, crucible temperature in several seconds is elevated to 1200 degree, water sample meeting conflagration, carbon wherein and oxygen reaction generate carbon dioxide, and the carbon dioxide of generation is delivered to optical measurement unit and measured.Heating flame unit is airtight, and burning carries out in the firing chamber that quartz ampoule is made, and just carries out oxygen blast before burning starts, and the carbon dioxide that burning produces is delivered in measuring chamber.
The advantage of heating flame unit is: use molybdenum gold copper-base alloy to manufacture crucible, can play the effect of catalytic oxidation in combustion process, be more conducive to burning; Water sample is that liquid form joins in crucible, and the volume added is large, is generally ten times of Sprayable, can adds 100 microlitres, and water sample is representative strong, and the accuracy of measurement is higher; Crucible can reuse, and is conducive to the Quick Measurement of different water sample.
Prepurge unit is by pressure control mechanism, firing chamber, form except water pipe, adsorption tube, optical absorption pipe, air valve, connecting line.
Pressure control mechanism mainly controls the pressure of whole oxygen blast gas circuit, makes pressure remain on a stable level, ensures the stability of air-flow, be conducive to the stability measured.Firing chamber is a part for gas circuit, is the place of water sample burning.Except water pipe is connected on the rear portion of firing chamber, the carbon dioxide that burning produces contains a large amount of water vapor, adopts electronic cooling to produce sub-zero low-temperature space, will place wherein except water pipe, carbon dioxide discharges through forming water except the condensation of water pipe water vapor chance, reaches the object dewatered.Adsorption tube is connected on the rear portion except water pipe, and through after water pipe, in carbon dioxide, most of water is removed, and also there is the water vapor of trace, more completely clean after the drying agent absorption in adsorption tube.Optical absorption pipe is the place that carbon dioxide absorbs infrared light, optical absorption pipe one end connects infrared light supply, the other end connects infrared receiver sensor, the infrared light that light source produces is irradiated on the infrared sensor of the other end through optical absorption pipe, carbon dioxide enters from one end, from other end removing, period, a part of infrared light was absorbed.The effect of air valve is the break-make controlling gas.The effect of connecting line is firing chamber, except water pipe, adsorption tube, optical absorption pipe, air valve link together, and forms an airtight air-channel system, the carbon dioxide of generation is discharged after each several part.
Optical measurement unit comprises infrared light supply, optical absorption pipe, infrared receiver sensor, photoelectric conversion circuit, signal modulating system, signal amplification circuit.
Infrared light supply is the device producing infrared light, can produce the infrared light of required specific wavelength, requires the wavelengths centered frequency stabilization producing light, the power stability of light.Optical absorption pipe is made up of glass tube surface gold-plating, requires smooth surface, cleaning, reduces loss and the refraction of light signal, signal is propagated in a linear fashion.The effect of infrared receiver sensor is that light signal is transformed into electric signal, and the scope of sensor Received signal strength will meet the absorption frequency of carbon dioxide.The effect of photoelectric conversion circuit is that the current signal of sensor conversion is converted to voltage signal, and carries out filtering, stable process to electric signal.Signal modulating system converts AC signal to DC signal.The effect of signal amplification circuit carries out elementary amplification to electric signal, to adapt to the requirement of data handling system.
Data handling system comprises: the amplification of data and collection, data calculating, data display and output.
Electric signal through amplifying and filtering, will reach the requirement to signal, carrying out digital signal conversion, gathered by single-chip microcomputer to signal simulating signal.
Data calculate will complete data operation, according to optical laws, calculate survey the concentration of solution.
Data display and export and mainly complete the display of data, printing, storage, by the data of liquid crystal display display measurement, realized the instant printing of data by mini-printer, data can be stored by instrument self, also can transmit data to PC.
The signal that signal transacting and amplifying circuit are mainly sent here pre-amplification circuit carries out filtering and signal amplifies, and carrys out adaptive circuit requirement.Analog to digital conversion circuit converts digital signal the electric signal after process to by simulating signal, adapts to the requirement of single-chip microcomputer.Single chip circuit Main Function simply calculates signal and processes, and is made into packet, send external computer to calculate; Single-chip microcomputer also processes the steering order that computer is sent here, performs corresponding action.The Main Function of external computer is that the data sent here instrument are classified, calculate, processed, and exports and store result, display data waveform.
Control system is made up of two parts, and one is the control of instrumentation, and two is the control of each solenoid valve of instrument and motor.
Instrumentation controls to be completed by computer instruction, controls, performed by the respective menu of operating instrument the individual event of instrument.To the control of each solenoid valve of instrument and motor, by computer, steering order is sent to the single-chip microcomputer of instrument, after instruction being explained by single-chip microcomputer, convert control signal to, carry out the control of corresponding actions.Based Intelligent Control signal, by sending computer process after single-chip microcomputer collection, send instrument to perform after computer process.
With above-mentioned foundation the preferred embodiments of the present invention for enlightenment, by above-mentioned description, relevant staff in the scope not departing from this invention technological thought, can carry out various change and amendment completely.The technical scope of this invention is not limited to the content on instructions, must determine its technical scope according to right.