Background technology
In polyphasic flow reactor fluid mechanics parameter field tests, the measurement of concetration of suspended particle is a requisite importance.Parameter test method is of a great variety, can be divided into intrusive mood and non-intrusion measurement method by the physical principle of detection method.
For non-intrusion type, to measurement system, Particle Image Velocity instrument (PIV) and Laser Doppler Velocimeter (LDV) all require that printing opacity dispersed phase volume fraction is less than 5%, can be used for from low speed until the measurement of the astable flow field velocity of hypervelocity; Its application of ultrasound tomography technology (UCT) is confined to disperse phase content lower than 20% and cannot measure in real time.Above-mentioned several comparatively conventional means of testing is confined to phase content and cannot measures in real time, and corresponding instrument is very expensive.
For intrusive mood, the most conventional no more than direct sample and reflection-type optical fiber probe.Obtain representative sample, direct sampling method there are certain requirements sample rate and volume, and the concentration detection method of institute's sample thief be mainly dry weight method (by suspending liquid repeatedly centrifuge washing and weigh the quality of separating particles to calculate the method for suspension concentration after dry process), operating process is complicated.Along with going deep into of research, photoelectric detection method starts to occur.Photoelectric detection method is according to the suspending liquid of variable concentrations to the scattering of the light method of determining concentration different from absorption, because of its fast, accurately and automaticity is high, become the main stream approach that suspension concentration detects very soon.Photoelectric detection method is divided into scattering method, transmission beam method and falls apart thoroughly than method etc.These three kinds of methods are detect to determine granule density by the ratio of scattered light intensity, transmitted intensity and scattered light and transmitted intensity after suspending liquid respectively.Reflection-type optical fiber probe photoelectric detection method category owned by France, but because black solid particle is to light reflection difference, therefore existing reflection-type optical fiber probe is not suitable for the Concentration Testing of black solid particle.
Summary of the invention
In view of this, the object of the present invention is to provide a kind of suspension particle concentration measuring apparatus and measuring method thereof, be applicable to black solid particle, draw the advantage of reflecting light nanofarads, improve measuring accuracy; Easy to use needs carries out sample aftertreatment, and cost is reasonable.
For achieving the above object, the present invention adopts following technical scheme: a kind of suspension particle concentration measuring apparatus, is characterized in that: comprise power supply, laser instrument, photoelectric cell, signal amplifier, data acquisition control system, computing machine and probe; Described laser instrument and photoelectric cell to be arranged on described probe and described laser instrument and photronic spacing adjustable, the light that described photoelectric cell sends for receiving described laser instrument; Described photoelectric cell is connected with described signal amplifier, and described signal amplifier is connected with described data acquisition control system, and described data acquisition control system is connected with described computing machine and power supply.
A measuring method for suspension particle concentration measuring apparatus, is characterized in that comprising the following steps:
Step S1: the concentration according to testing sample regulates laser instrument and photronic spacing, regulates principle to be that concentration to be measured is higher, selects spacing less;
Step S2: be positioned in testing sample by described probe, switches on power for measuring instrument is powered simultaneously, makes laser instrument emission of light;
Step S3: photoelectric cell receives described light through the light signal after described testing sample, and this light signal is converted to electric signal;
Step S4: described electric signal carries out returning to zero and amplifying process through described signal amplifier, then transfers to computing machine through described data acquisition control system and carries out processing and obtain light through the magnitude of voltage after testing sample;
Step S5: the suspension particle concentration obtaining testing sample according to described magnitude of voltage and voltage-suspension particle concentration curve.
The present invention compared with prior art has following beneficial effect: the present invention is used for reactor inner suspension liquid granule density and measures, and is applicable to black solid particle, has drawn the advantage of reflecting light nanofarads, the resolution of instrument is improved a lot; Meanwhile, probe emission end and receiving end distance with can survey concentration range and there is corresponding relation, instrument is suitable for wider.
Embodiment
Below in conjunction with drawings and Examples, the present invention will be further described.
Please refer to Fig. 1, the invention provides a kind of suspension particle concentration measuring apparatus, comprise power supply, laser instrument, photoelectric cell, signal amplifier, data acquisition control system, computing machine and probe, please refer to Fig. 2, described laser instrument 2 and photoelectric cell 3 are arranged on described probe 1 and described laser instrument 2 is adjustable with the spacing of photoelectric cell 3, and in one embodiment of the invention, this spacing is 5mm, the light that described photoelectric cell 3 sends for receiving described laser instrument 2, in order to meet collimate light, described probe is rigid structure, guarantee the light that photoelectric cell 3 in just measuring process can receive laser instrument 2 and sends, described photoelectric cell is connected with described signal amplifier, described signal amplifier returns to zero to the signal that photoelectric cell transmits, amplify, described signal amplifier is connected with described data acquisition control system, described data acquisition control system is connected with described computing machine and power supply, described power supply is that whole measuring instrument is powered, described data acquisition control system is used for the data of collection signal amplifier transfer, the magnitude of voltage obtained after obtaining by the process of computing machine the light therethrough testing sample sent from laser instrument 2.
Described laser instrument 2 is on-dispersive light source, and the wavelength of the light sent is 650nm, and it can obtain from the semiconductor laser of cheapness, and light penetration testing sample is to the photoelectric cell 3 of the other end.Light arrives photoelectric cell 3 two kinds of modes: one is directly project on photoelectric cell 3; Two be light after the Multiple Scattering of suspended particle in testing sample, finally scatter on photoelectric cell 3.Arrive photoelectric cell 3 and carry out opto-electronic conversion, the electric signal after conversion enters into signal amplifier and data acquisition control system.At signal amplifier and data acquisition control system, signal is through zeroing, amplification and gather, and can obtain the magnitude of voltage of light therethrough testing sample, can be extrapolated the granule density of testing sample by the voltage of testing sample.
For transmitted light Concentration Testing method; the incident parallel light (if divergent beams need through collimation process) sent from light source enters in the middle of suspending liquid; particle in suspending liquid can produce scattering and absorption to light; light (i.e. transmitted light) intensity through suspending liquid is reduced; theoretical according to Lambert-Beer; by the impact of suspended particle content, there is certain function corresponding relation between the two, draw the content of particle in suspending liquid with this in the attenuation degree of transmitted light.
Described photronic spectral range 300nm-1000nm, peak wavelength is 700nm.
Described signal amplifier is programmable signal amplifier, and its enlargement factor is adjustable.
The present invention also provides a kind of measuring method of suspension particle concentration measuring apparatus, comprises the following steps:
Step S1: the concentration according to testing sample regulates laser instrument and photronic spacing, regulate principle to be that concentration to be measured is higher, select spacing less, laser instrument and photoelectric cell spacing range are 1-50mm;
Step S2: be positioned in testing sample by described probe, switches on power for measuring instrument is powered simultaneously, makes laser instrument emission of light;
Step S3: photoelectric cell receives described light through the light signal after described testing sample, and described light signal is converted to electric signal;
Step S4: described electric signal carries out returning to zero and amplifying process through described signal amplifier, then transfers to computing machine through described data acquisition control system and carries out processing and obtain light through the magnitude of voltage after testing sample;
Step S5: the suspension particle concentration obtaining testing sample according to described magnitude of voltage and voltage-suspension particle concentration curve.Be illustrated in figure 3 the voltage-suspension particle concentration curve schematic diagram of one embodiment of the invention.
Voltage-concentration curve in described step S5 is drawn by rating test, and concrete steps are as follows: the solids suspension of configuration variable concentrations, records the light of laser instrument transmitting through the magnitude of voltage after each concentration of solids particle suspension liquid respectively with measuring instrument; Set up voltage-suspension particle concentration coordinate system, by marking in voltage-suspension particle concentration coordinate system after the concentration of each solids suspension and the magnitude of voltage one_to_one corresponding that records and making curve, obtain voltage-suspension particle concentration curve.
Especially, before rating test, need by high-speed stirred thus make the even particle distribution of the solids suspension of each concentration, needing by the localized rich angle value in different position measurement demarcation systems on the other hand, ensureing even concentration.Concentration in rating test is that proportioning is good in advance, and magnitude of voltage is directly read by measuring instrument.
The detection of overall process has been controlled automatically by data acquisition control system, described data acquisition control system first controls the light that laser instrument sends some strength, then the magnitude of voltage produced after arriving photoelectric cell to light therethrough testing sample is sampled, and contrasts the granule density value that the voltage-suspension particle concentration curve obtained by rating test directly reads testing sample.
The foregoing is only preferred embodiment of the present invention, all equalizations done according to the present patent application the scope of the claims change and modify, and all should belong to covering scope of the present invention.