CN101968426B - Dust concentration sensor - Google Patents
Dust concentration sensor Download PDFInfo
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- CN101968426B CN101968426B CN2010102940935A CN201010294093A CN101968426B CN 101968426 B CN101968426 B CN 101968426B CN 2010102940935 A CN2010102940935 A CN 2010102940935A CN 201010294093 A CN201010294093 A CN 201010294093A CN 101968426 B CN101968426 B CN 101968426B
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Abstract
The invention discloses a dust concentration sensor comprising a sampling unit, a photoelectric conversion unit, a signal amplifying unit and a processing unit, wherein the sampling unit pumps outside air containing dust into the sensor, and the air passes through the photoelectric conversion unit; the photoelectric conversion unit provides a light source which irradiates passing air containing dust, and generates scattered light, the scattered light is converted into a voltage output signal, and the voltage output signal is output to the signal amplifying unit; the signal amplifying unit is connected with a semiconductor optical detector to process, amplify and output the received signal; the processing unit is connected with the signal amplifying unit; and based on the voltage signal output by the signal amplifying unit and the proportion relationship between a pre-stored voltage signal and dust concentration, powder concentration is calculated. The invention has reasonable structure, good measurement stability, high sensitivity precision and easy maintenance.
Description
Technical field
The present invention relates to a kind of air purity checkout equipment, be specifically related to a kind of sensor of dust concentration.
Background technology
Present measurement for dust concentration; Mainly contain following several kinds of modes: a kind of employing dust sampler; Utilize the heavy method principle of filter membrane meter: the dust laden air that extracts certain volume; Dust is trapped on the filter membrane, according to the dust quality that increases on the filter membrane, utilizes formula to calculate dust mass concentration in the unit volume air again.This mode not only is not easy to operation, and can not continuous coverage.A kind of is the direct-reading dust gauge; Mainly utilize principles such as indirect method such as light scattering, the absorption of β source, utilize sampling thief to demarcate, but the dust concentration value that instant playback is measured is come; But the working time is short; The measurement number of times is limited, can not can only use as the portable dust gauge of routine the dust continuous monitoring.
But but develop a kind of continuous detecting direct-reading dust concentration sensor continuous detecting dust concentration now.
The patent No. is " CN200620125097.X "; Patent name " a kind ofly carries out long-time continuous monitoring and instant playback dust concentration value to dust concentration, converts the sensor that frequency signal is exported simultaneously to for the Chinese patent of " sensor of dust concentration " disclose.Structure is made up of shell, dust sampling head, dust room, blower fan, photoelectric receiving arrangement; " " photoelectric receiving arrangement comprises light source base, light source shelf, light source sealing shroud, photomultiplier ".The disclosed sensor of dust concentration of this patent can be implemented in the continuous working under the dust atmosphere, but because of it uses photomultiplier, during use higher voltage need be provided, and this has constituted potential safety hazard in the dust work place.
Summary of the invention
The objective of the invention is to overcome above-mentioned shortcoming of the prior art, a kind of photomultiplier that need not is provided, stable sensitivity is high, and small and exquisite powder concn sensor rational in infrastructure.
A kind of powder concn sensor of the present invention comprises sampling unit, photoelectric conversion unit, signal amplification unit, processing unit,
Said sampling unit, with the said sensor internal of extraneous dust laden air suction, and through photoelectric conversion unit;
Photoelectric conversion unit provides a light source, the dust laden air of irradiation process, and produce scattered light, convert said scattered light into voltage output signal, and export said voltage signal to signal amplification unit; Said photoelectric conversion unit comprises a semiconductor laser light resource that sends laser beam, sends at this LASER Light Source on the working direction of light beam, is provided with incident light passage, area of illumination, emergent light passage, light trapping successively; Through area of illumination and be provided with spherical reflector, semiconductor light detector with the light path vertical direction, spherical reflector and photo-detector are respectively on the both sides of area of illumination; Said air inlet tube and outgoing gas connection tube are symmetrically distributed in the both sides of area of illumination, and air inlet tube is in the upper end of area of illumination, and outgoing gas connection tube is in the lower end of area of illumination, and the caliber of said air inlet tube is less than the caliber of outgoing gas connection tube; The pore of said air inlet tube is offset flat shape;
Signal amplification unit links to each other with semiconductor light detector in the photoelectric conversion unit, the electric signal that receives is handled amplified and output.
Processing unit is connected with signal amplification unit, calculates powder concn based on the voltage signal of signal amplification unit output and the proportionate relationship of voltage signal that prestores and powder concn.
In a preferred embodiment of the invention; Said sampling system comprises thief hatch, draft tube, gas outlet, exhausr port, and said thief hatch connects draft tube, and draft tube is passed said photoelectric conversion unit and connected the sampling pump inlet; The sampling pump outlet connects gas outlet, and gas outlet connects exhausr port.
In a preferred embodiment of the invention, said photoelectric conversion unit be provided with one with the extraneous cavity that communicates, this cavity is used to hold spherical reflector, is convenient to the dismounting of spherical reflector.
In a preferred embodiment of the invention, the power of said LASER Light Source is the 2-3.5 milliwatt.
In a preferred embodiment of the invention, said light trapping inwall is a black.
In a preferred embodiment of the invention, said semiconductor photo detector is high sensitive photodiode.
In a preferred embodiment of the invention, said signal amplification unit comprises differential amplifier circuit, signal detection circuit, integration and output circuit;
Said differential amplifier circuit, with the semiconductor light detector electric connection in the photoelectric conversion unit, this differential amplifier circuit carries out differential, amplification to the electric signal of input;
Said signal detection circuit electrically connects with this differential amplifier circuit, and this signal detection circuit is taken a sample to the electric signal after differential amplifier circuit differential, amplification and detected;
Said integration and output circuit; Electrically connect with this signal detection circuit, this integration and output circuit receive the result that sampling detects from signal detection circuit, and this result is carried out integration; And convert direct current signal into the dust concentration size variation, again this direct current signal is transferred to this processor.
In a preferred embodiment of the invention; Said differential amplifier circuit comprises operational amplifier, electric capacity and resistance; This differential amplifier circuit carries out differential, amplification to the electric signal that is converted by the dust light signal that receives from photoelectric conversion unit, is amplitude, the different electric signal of width with the different switching of shape by size with this dust light signal.
In a preferred embodiment of the invention, this signal detection circuit comprises a high-frequency diode.
In a preferred embodiment of the invention, this integration and output circuit comprise amplifier, resistance, electric capacity, and wherein, this resistance and electric capacity constitute a time constant circuit.
The present invention compares its advantage with the prior art scheme: rational in infrastructure, and good measuring stability, the sensitivity precision is high, easy care.
Description of drawings
Fig. 1 is a kind of embodiment inner structure synoptic diagram of the present invention;
Fig. 2 looks synoptic diagram for the right side of Fig. 1;
Fig. 3 looks synoptic diagram for the left side of Fig. 1;
Fig. 4 is a kind of structural representation of photoelectricity conversion unit;
Fig. 5 is Fig. 4 vertical view cutaway drawing;
Fig. 6 is the sectional view of air inlet tube in the prior art;
Fig. 7 is the sectional view of air inlet tube in the present embodiment;
Fig. 8 is the functional-block diagram of signal amplification unit of the present invention.
Wherein, 1 is casing; 2 is signal processing unit; 3 are the insulation fixed head; 4 is draft tube; 5 is thief hatch; 6 is photoelectric conversion unit; 7 is signal amplification unit; 8 is exhausr port; 9 are the suspension handle; 10 is interface; 11 is sampling pump; 12 is gas outlet; 61 is LASER Light Source; 62 is the total mount pad of photoelectricity conversion unit; 63 is air inlet tube; 64 is outgoing gas connection tube; 65 is photodetector; 66 is the light source mount pad; 68 is spherical reflector; 621 is emitting light path; 622 is input path; 623 is light trapping; 631 is pore; 632 is tube wall; 71 is differential amplifier circuit; 72 is signal detection circuit; 73 is integration and output circuit; 74 is circuit board; 75 is the circuit mount pad.
Embodiment
Below in conjunction with accompanying drawing preferred embodiment of the present invention is set forth in detail, thereby protection scope of the present invention is made more explicit defining so that advantage of the present invention and characteristic can be easier to it will be appreciated by those skilled in the art that.
Combine Fig. 2, shown in Figure 3 like Fig. 1; The sensor of present embodiment comprises casing 1, signal processing unit 2, insulation fixed head 3, draft tube 4, thief hatch 5, photoelectric conversion unit 6, signal amplification unit 7, exhausr port 8, suspension handle 10, sampling pump 11, gas outlet 12.Thief hatch 5 is in the upper end, left side of casing 1; Connect draft tube 4; Draft tube 4 is passed photoelectricity conversion unit 6 and is connected the sampling pump inlet, and the sampling pump outlet connects gas outlet 12 again, and exhausr port 8 is in the bottom of casing 1; Photoelectric conversion unit 6 connects signal amplification unit 7, and signal amplification unit 7 connects signal processing unit 2 again.Thief hatch 5, draft tube 4, sampling pump 11, gas outlet 12, exhausr port 8 are formed the sampling system unit.Insulation fixed head 3 is divided into former and later two spaces with space in the casing; Sampling system unit and photoelectric conversion unit 6 are arranged and are fixed on the insulation fixed head; Be positioned at the space of the back of casing, signal processing unit 2 is fixed on the another side of insulation fixed head, is positioned at the space of the front of casing.Suspension handle 9 is equipped with in the casing upper end, can the sensor of present embodiment be suspended on eminence and use.
Combine shown in Figure 5ly like Fig. 4, total mount pad 62 is a rectangular structure, and there is a circular space centre as area of illumination, and LASER Light Source 61 is installed in the left end mounting hole of total mount pad 62, is fixed on total mount pad through mount pad 67, can connect through screw.In total mount pad 62 right-hand member mounting holes the closure of openings of a black object with mounting hole arranged, form light trapping.Be connected to air inlet tube 63 in total mount pad 62 upper end holes, be connected to outgoing gas connection tube 64 in the following stomidium, said air inlet tube 63, outgoing gas connection tube 64 all extend inward into the light area.In total mount pad 62 front end mounting holes spherical reflector 68 is installed, photodetector 65 is installed in the mounting hole of rear end, photodetector 65 is connected with signal amplification unit 7.Circuit board 74 is fixedly connected on the back of total mount pad 62 through circuit mount pad 75.
As shown in Figure 6, dust laden air is rotating the entering admission line under the effect of sampling pump 11; The pore 631 of air inlet tube 63 of the prior art is rounded, thereby makes dust granules closeer in the tube chamber central distribution, and peripheral distribution is laxer; Skewness can influence measuring accuracy like this, simultaneously when dust concentration acquires a certain degree; Overstocked because of tube chamber center dust density, make and can't continue to measure, thereby range ability is little.
As shown in Figure 7, the pore 631 of the air inlet tube 63 of present embodiment is flat, and dust granules is clashed in tube wall, and it is forced shaping, changes its regularity of distribution, and dust granules is evenly distributed, thereby improves measuring accuracy, improves range ability simultaneously.
The inwall of light trapping 623 all is a black, but absorbing light, and no reflection events can not produce interference.
The caliber of outgoing gas connection tube 64 forms approximate infundibulate greater than the caliber of air inlet tube 63, and is long-pending thereby the dust granules in the minimizing dust laden air pushes away in area of illumination, and then can reduce maintenance times.
Spherical reflector 68 is detachable the installation, so conveniently spherical reflector is pulled down cleaning, and present embodiment is to be fixed in the mounting hole of total mount pad with the black adhesive plaster, also can use other detachable mounting means that gets.
Photodetector 65 can be selected high sensitive photodiode for use.
LASER Light Source 61 is optional to use power as the 2-3.5 milliwatt.
The work of the sensor of present embodiment is divided into two parts:
The one, sampling section: start sampling pump 11; With extraneous dust laden air from gas production mouth suction draft tube; Draft tube connects air inlet tube 63; Get into photoelectricity conversion unit 6, discharging photoelectricity conversion unit 6 entering sampling pumps 11 from outgoing gas connection tube 64, the outlet of sampling pump 11 connects gas outlet 12 air is discharged sensors from exhausr port 8.
The 2nd, the test section: dust laden air gets into from air inlet tube 63, through area of illumination, discharges at outgoing gas connection tube 64.LASER Light Source 61 gets into from input path 622, through area of illumination, gets into light trapping 623 from emitting light path 621.When light when area of illumination shines the dust granules in the dust laden air; Can reflect; Part refract light is the photosensitive area of refraction entering photo-detector 65 directly; Another part can be refracted on the spherical reflector 68, and by the photosensitive area of specular reflective mirrors 68 with refract light refraction entering photo-detector 65, photo-detector is changed to voltage signal with the light signal dress that receives and is transferred to signal amplification unit 7 again.Voltage signal after signal amplification unit 7 will amplify is input to signal processing unit 2 and handles.
As shown in Figure 8, said signal amplification unit 7 comprises differential amplifier circuit 71, signal detection circuit 72, integration and output circuit 73, and said signal amplification unit one of which end connects photoelectric conversion unit 6, and the other end is connected to signal processing unit 2.Wherein, differential amplifier circuit 71 comprises elements such as operational amplifier, electric capacity, resistance, and differential amplifier circuit 71 stability is high, and its enlargement factor is up to 100,000 times, and can self-excitation.Differential amplifier circuit 71 receives the dust electric signal that dust senses from air from photoelectric conversion unit 6; And this electric signal carried out differential, amplification; And then with detected dust light signal different with shape by size, convert amplitude, the different electric signal of width into.
Integration and output circuit 73 comprise elements such as amplifier, resistance, electric capacity, and wherein, resistance and electric capacity are used to constitute the integration circuit time constant circuit.73 pairs of electric signal from signal detection circuit 72 outputs of this integration and output circuit carry out the dust light signal that integration detects with reduction, and convert the direct current signal with the dust concentration size variation into.Afterwards, this integration and output circuit 73 export this direct current signal to signal processing unit 2 and handle, with dust content in the statistics air.Wherein, signal processing unit 2 comprise central processing unit (center processing unit, CPU) or computing machine.
Signal amplification unit 7 of the present invention has adopted stable high differential amplifier circuit 71; This differential amplifier circuit 71 can be accomplished to amplify hundreds thousand of times to signal, and can self-excitation, has reduced the circuit number of stages of amplification; Thereby overcome the zero point drift problem of direct current amplifier, improved the stability of equipment.Simultaneously, small dust signal be can collect easily, precision of detection and sensitivity improved greatly.Principle according to the differential amplification; This dust detection system can detected dust light signal by size with different amplitude, the different electric signal of width of changing into of shape; Through detecting circuit, integrating circuit; Directly transfer direct current signal to, use for the processor statistics with the dust concentration size variation.The present invention's stability is strong, measuring accuracy is high, can be widely used in the industrial sector that dust is contained in cement mill, coal works etc.
The above; Be merely embodiment of the present invention; But protection scope of the present invention is not limited thereto; Any those of ordinary skill in the art are in the technical scope that the present invention disclosed, and variation or the replacement that can expect without creative work all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection domain that claims were limited.
Claims (8)
1. a powder concn sensor comprises sampling unit, photoelectric conversion unit, signal amplification unit, and processing unit is characterized in that:
Said sampling unit, with the said sensor internal of extraneous dust laden air suction, and through photoelectric conversion unit;
Photoelectric conversion unit provides a light source, the dust laden air of irradiation process, and produce scattered light, convert said scattered light into voltage output signal, and export said voltage signal to signal amplification unit; Said photoelectric conversion unit comprises a semiconductor laser light resource that sends laser beam, sends at this LASER Light Source on the working direction of light beam, is provided with incident light passage, area of illumination, emergent light passage, light trapping successively; Through area of illumination and be provided with spherical reflector, semiconductor light detector with the light path vertical direction, spherical reflector and photo-detector are respectively on the both sides of area of illumination; Said air inlet tube and outgoing gas connection tube are symmetrically distributed in the both sides of area of illumination, and air inlet tube is in the upper end of area of illumination, and outgoing gas connection tube is in the lower end of area of illumination, and the caliber of said air inlet tube is less than the caliber of outgoing gas connection tube; The pore of said air inlet tube is offset flat shape;
Signal amplification unit links to each other with semiconductor light detector in the photoelectricity conversion unit, the electric signal that receives is handled amplified and output;
Said signal amplification unit comprises differential amplifier circuit, signal detection circuit, integration and output circuit;
Said differential amplifier circuit; Electrically connect with the semiconductor light detector in the photoelectric conversion unit; This differential amplifier circuit carries out differential, amplification to the electric signal of input; Said differential amplifier circuit comprises operational amplifier, electric capacity and resistance, and this differential amplifier circuit carries out differential, amplification to the electric signal that is converted by the dust light signal that receives from photoelectric conversion unit, is amplitude, the different electric signal of width with the different switching of shape by size with this dust light signal;
Said signal detection circuit electrically connects with this differential amplifier circuit, and this signal detection circuit is taken a sample to the electric signal after differential amplifier circuit differential, amplification and detected;
Said integration and output circuit; Electrically connect with this signal detection circuit, this integration and output circuit receive the result that sampling detects from signal detection circuit, and this result is carried out integration; And convert direct current signal into the dust concentration size variation, again this direct current signal is transferred to this processor;
Processing unit is connected with signal amplification unit, calculates powder concn based on the voltage signal of signal amplification unit output and the proportionate relationship of voltage signal that prestores and powder concn.
2. a kind of powder concn sensor according to claim 1; It is characterized in that: said sampling unit comprises thief hatch, draft tube, gas outlet, exhausr port; Said thief hatch connects draft tube; Draft tube is passed said photoelectric conversion unit and is connected the sampling pump inlet, and the sampling pump outlet connects gas outlet, and gas outlet connects exhausr port.
3. a kind of powder concn sensor according to claim 1 is characterized in that: said photoelectric conversion unit be provided with one with the extraneous cavity that communicates, this cavity is used to hold spherical reflector, is convenient to the dismounting of spherical reflector.
4. a kind of powder concn sensor according to claim 3 is characterized in that: the power of said LASER Light Source is the 2-3.5 milliwatt.
5. a kind of powder concn sensor according to claim 4 is characterized in that: said light trapping inwall is a black.
6. according to the described a kind of powder concn sensor of one of claim 3 to 5, it is characterized in that: said semiconductor light detector is high sensitive photodiode.
7. powder concn sensor according to claim 1 is characterized in that this signal detection circuit comprises a high-frequency diode.
8. powder concn sensor according to claim 1 is characterized in that this integration and output circuit comprise amplifier, resistance, electric capacity, and wherein, this resistance and electric capacity constitute a time constant circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010102940935A CN101968426B (en) | 2010-09-27 | 2010-09-27 | Dust concentration sensor |
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| Application Number | Priority Date | Filing Date | Title |
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| CN2010102940935A CN101968426B (en) | 2010-09-27 | 2010-09-27 | Dust concentration sensor |
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| CN101968426A CN101968426A (en) | 2011-02-09 |
| CN101968426B true CN101968426B (en) | 2012-07-25 |
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| CN104914026B (en) * | 2015-06-12 | 2018-08-07 | 艾欧史密斯(中国)热水器有限公司 | Dust concentration detecting method and sensor of dust concentration |
| CN106680168B (en) * | 2017-02-20 | 2023-10-27 | 常熟市顺欣仪器仪表有限公司 | Dust concentration measuring device |
| CN106872326B (en) * | 2017-04-12 | 2020-05-05 | 广东美的制冷设备有限公司 | Automatic zero setting method of dust sensor |
| CN107748122A (en) * | 2017-09-30 | 2018-03-02 | 温州市洞头新博机电有限公司 | A kind of dust sensing device |
| CN108680476A (en) * | 2018-06-20 | 2018-10-19 | 苏州百创达环保科技有限公司 | A kind of particle concentration detection device |
| CN109406360A (en) * | 2018-12-27 | 2019-03-01 | 常熟市德虞矿山机电有限公司 | A kind of sensor of dust concentration detection device |
| CN112014284B (en) * | 2020-08-27 | 2023-11-24 | 苏州亿利安机电科技有限公司 | Direct-reading dust concentration measuring instrument |
| CN113820258A (en) * | 2021-09-09 | 2021-12-21 | 麦克微尔(天津)科技有限公司 | Dust particle detection device |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101487786A (en) * | 2008-01-18 | 2009-07-22 | 南京理工大学 | Measurement sensor for inhalable dust concentration |
| CN101598657A (en) * | 2009-07-02 | 2009-12-09 | 煤炭科学研究总院常州自动化研究院 | The method of a kind of sensor of dust concentration and measurement dust concentration thereof |
| CN101793669A (en) * | 2010-02-09 | 2010-08-04 | 南京理工大学 | Optical sensor of novel high-output all-semiconductor dust particle counter |
-
2010
- 2010-09-27 CN CN2010102940935A patent/CN101968426B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101487786A (en) * | 2008-01-18 | 2009-07-22 | 南京理工大学 | Measurement sensor for inhalable dust concentration |
| CN101598657A (en) * | 2009-07-02 | 2009-12-09 | 煤炭科学研究总院常州自动化研究院 | The method of a kind of sensor of dust concentration and measurement dust concentration thereof |
| CN101793669A (en) * | 2010-02-09 | 2010-08-04 | 南京理工大学 | Optical sensor of novel high-output all-semiconductor dust particle counter |
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