JP6571709B2 - Particle measuring apparatus and air purifier - Google Patents

Description

  The present invention relates to a particle measuring device that measures particles contained in a fluid that is a gas or a liquid, an air purifier that includes the particle measuring device, and a particle measuring method.

  The light scattering type particle detection sensor is a photoelectric sensor including a light projecting element and a light receiving element, takes in a gas to be measured, irradiates the light of the light projecting element, and includes the light by the scattered light. The presence or absence of particles to be detected is detected. For example, particles such as dust, pollen, and smoke floating in the atmosphere can be detected.

  As a particle measuring apparatus including this kind of light scattering type particle detection sensor, particles contained in the atmosphere are detected from particles having a small particle size (micro particles) using a detection signal from the light scattering type particle detection sensor. A method for measuring particles (coarse particles) and a method for ensuring long-term reliability of the particle measuring apparatus has been described (see Patent Document 1).

Japanese Patent Laid-Open No. 2006-128795

  Patent Document 1 solves the problem that coarse particles may not be measured when the apparatus is adjusted according to the particle size of fine particles. (I) The above-described sensor signal included in the sensor signal indicating the output from the light receiving element. When the peak value of the pulse waveform corresponding to the particle is less than a predetermined threshold value, the particle size of the particle is calculated using the peak value. (Ii) When the peak value is equal to or greater than the threshold value, the predetermined value less than the threshold value is calculated. And a calculation unit that calculates the particle size of the particles using the time width of the pulse waveform at the value of.

  However, this technique has a problem in measurement when the concentration of particles is high.

  Specifically, if the concentration of particles is high, multiple pulse waveforms corresponding to the particles included in the sensor signal overlap, so the peak value reading cannot be directly matched to the particle size, or multiple peaks are displayed. There may occur a case where a single peak is mistakenly determined to be a coarse particle.

  Accordingly, an object of the present invention is to provide a particle measuring apparatus and the like that can more appropriately grasp the size distribution of particles even when the particles are present at a high concentration.

In order to achieve the above object, a particle measuring apparatus according to one embodiment of the present invention is a particle measuring apparatus that measures the particle size of particles contained in a fluid that is a gas or a liquid, and projects light onto a detection region. A particle detection sensor having a light projecting element that receives light and a light receiving element that receives scattered light of the light scattered by the particles located in the detection region, and the particles included in a sensor signal indicating an output from the light receiving element For the waveform corresponding to the above, the particle size is calculated based on a calculation using a difference between the peak start value and the peak start value and a coefficient determined by the peak start value .

  In addition, the form which calculates the particle size of this invention may be the form integrated with the particle | grain measuring apparatus as a structure, and the form in which another apparatus plays a role for a part of function may be sufficient.

  ADVANTAGE OF THE INVENTION According to this invention, the particle | grain measuring apparatus etc. which can grasp | ascertain distribution of the magnitude | size of a particle | grain more appropriately also with a high concentration particle | grain can be provided.

It is a block diagram which shows an example of a structure of the particle | grain measuring apparatus which concerns on embodiment. It is a figure which shows an example of a structure of the particle | grain detection sensor of the particle | grain measuring apparatus which concerns on embodiment. It is a figure which shows the image in which particle | grains are detected in the detection area | region which concerns on embodiment. It is a wave form diagram which shows an example which converted the electric current signal output from the light receiving element which concerns on embodiment into the voltage signal. It is a figure for demonstrating the wave form diagram of FIG. 4 which concerns on embodiment. It is an image figure for demonstrating the relationship between the waveform figure of FIG.4 and FIG.5 which concerns on embodiment, and the particle | grains detected. It is a flowchart which shows operation | movement of the signal processing part which concerns on embodiment. It is a flowchart which shows the particle size calculation process which concerns on embodiment. It is a figure which shows an example of the result detected and calculated by the fly ash in the air which concerns on embodiment. It is a figure which shows an example of the result detected and calculated for every predetermined time by the fly ash in the air which concerns on embodiment. It is an example of the particle size distribution of the fly ash which concerns on embodiment. In the fly ash in the air which concerns on embodiment, it is a figure which shows the relationship between a particle size and the fall time from 1 m in height. In the fly ash in the air which concerns on embodiment, it is a figure which shows the particle size distribution which carried out the arithmetic process in consideration of falling from height 1m. It is the conversion example to the particle size of the sensor signal which concerns on embodiment. It is an example of the flowchart which compares the detection result of a sensor, and the calculation result which considered the sedimentation velocity type | formula in the fly ash in the air which concerns on embodiment. In the fly ash in the air which concerns on embodiment, it is a figure which compares the detection result of a sensor, and the calculation result which considered the sedimentation velocity type | formula. It is a figure which shows an example of the result detected and calculated for every predetermined time with Ishimatsu in the air which concerns on embodiment. These are examples of the particle size distribution of Ishimatsuko according to the embodiment. These are figures which show the relationship between a particle size and the fall time from height 1m in the stone mushroom in the air which concerns on embodiment. It is a figure which shows the particle size distribution which carried out arithmetic processing in consideration of falling from 1 m in height in the stone matsuko in the air which concerns on embodiment. It is a figure which shows an example of the result detected and calculated for every predetermined time in the fly ash and Ishimatsu in the air which concerns on embodiment. It is the figure which synthesize | combined the example (FIG. 10) of the fly ash in the air which concerns on embodiment, and the example (FIG. 16) of Ishimatsu. It is a figure which shows an example of the air cleaner which concerns on embodiment.

  Below, the particle | grain measuring apparatus etc. which concern on embodiment of this invention are demonstrated in detail using drawing. Note that each of the embodiments described below shows a preferred specific example of the present invention. Therefore, numerical values, shapes, materials, components, arrangement and connection forms of components, and steps and order of steps shown in the following embodiments are merely examples, and are not intended to limit the present invention. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims showing the highest concept of the present invention are described as optional constituent elements.

  Each figure is a mimetic diagram and is not necessarily illustrated strictly. Moreover, in each figure, the same code | symbol is attached | subjected about the same structural member, and the overlapping description may be abbreviate | omitted or simplified.

  First, the whole structure of the particle | grain measuring apparatus which concerns on embodiment of this invention is demonstrated. FIG. 1 is a block diagram illustrating an example of a configuration of a particle measuring apparatus according to an embodiment.

  As shown in the figure, the particle measuring apparatus 1 includes a particle detection sensor 2, an analog signal processing unit, a sensor module including a power supply unit, and a general-purpose MPU (Micro Processing Unit). Then, the particle size of particles contained in air (hereinafter referred to as ambient air) drifting in the vicinity of the particle measuring apparatus 1 according to the present embodiment is measured.

  As a modified example, another device may play a role for all or part of the signal processing unit.

Drawing 2 is a figure showing an example of the composition of the particle detection sensor of the particle measuring device concerning an embodiment.
Hereinafter, each structure of the particle | grain measuring apparatus 1 is demonstrated concretely.

  The particle detection sensor 2 is a photoelectric sensor including a light projecting element 3 and a light receiving element 4, and the light receiving element 4 receives light scattered from the light projecting element 3 by particles P in the detection region 9, so The particle P contained in the air is detected. The light projecting element 3, the light receiving element 4, and the detection region 9 are arranged inside the housing 10 so that external light is not irradiated, and the light projecting element 3 and the light receiving element 4 are held by the housing 10. Yes. Further, the particle detection sensor 2 in the present embodiment further includes a heating unit 11 that heats the surrounding air and causes a flow to be drawn into the internal space of the particle measuring device 1. When a means such as a fan for flowing a fluid is provided, the heating unit 11 may or may not be present.

  The light projecting element 3 is a light source (light emitting unit) that emits light of a predetermined wavelength, and is, for example, a solid light emitting element such as an LED (Light Emitting Diode) or a semiconductor laser. As the light projecting element 3, a light emitting element that emits infrared light, blue light, green light, red light, or ultraviolet light can be used. In this case, the light projecting element 3 may be configured to emit a mixed wave having two or more wavelengths. In the present embodiment, in view of the light scattering intensity by the particles P, for example, a bullet-type LED that outputs light having a wavelength of 400 nm to 1000 nm is used as the light projecting element 3.

  In addition, it becomes easy to detect the particle | grains P with a small particle size, so that the light emission wavelength of the light projection element 3 is short. The light emission control method of the light projecting element 3 is not particularly limited, and the light emitted from the light projecting element 3 can be continuous light or pulsed light by DC driving. Further, the magnitude of the output of the light projecting element 3 may change with time.

  The light emitted from the light projecting element 3 passes through the detection region 9 via a light projecting lens disposed in front of the light projecting element 3, for example. At this time, if the particle P passes through the detection region 9, the light from the light projecting element 3 is scattered by the particle P.

  The light receiving element 4 is a light receiving unit that receives light scattered from the light projecting element 3 by the particles P in the detection region 9. For example, the light receiving element 4 is a photo diode, a photo IC diode, a photo transistor, a photomultiplier tube, or the like. It is an element (photodetector) that receives and converts it into an electrical signal. Specifically, the light receiving element 4 generates a current signal as an electrical signal. That is, the light receiving element 4 outputs a current signal corresponding to the received light intensity.

  The scattered light from the particles P is collected on the light receiving element 4 by, for example, a light receiving lens disposed between the detection region 9 and the light receiving element 4.

  The housing 11 is a member provided with a particle flow path which is a cylindrical space region that provides light shielding properties and flows ambient air (gas) containing particles P. For example, the housing 10 is black at least on the inner surface so that stray light can be easily attenuated. Specifically, the reflection on the inner surface of the housing 10 may not be specular reflection, and a part of the light may be scattered and reflected.

  Here, the stray light is light other than the scattered light caused by the particles P. Specifically, the stray light is not scattered by the particles P in the detection region 9 out of the light emitted from the light projecting element 3. Traveling light, etc. Further, the stray light includes external light that has entered the inside of the housing 10 through the particle flow path.

  The housing 10 is formed, for example, by injection molding using a resin material such as ABS resin. At this time, for example, the inner surface of the housing 10 can be made a black surface by using a resin material to which a black pigment or dye is added. Or the inner surface of the housing | casing 10 can be made into a black surface by apply | coating a black coating material to an inner surface after injection molding. Further, stray light may be attenuated by performing surface treatment such as embossing on the inner surface of the housing 10.

  The detection area 9 is a particle P contained in the gas to be measured, and a spatial area where the light of the light projecting element 3 is projected and the scattered light generated by the light of the light projecting element 3 hitting the particle P to the light receiving element 4. It is a spatial region that overlaps the spatial region for guidance. The detection region 9 is set so as to exist in the particle flow path, and the gas to be measured enters the inside of the housing 10 from the inlet 12 of the particle flow path and is detected through the particle flow path. It is guided to the region 9 and flows out of the housing 10 from the outlet 13 of the particle channel.

  In the present embodiment, the flow direction of the particle flow path (the direction in which the gas to be measured flows) is the vertical direction on the paper surface of FIG. 2, but may be the vertical direction of the paper surface of FIG. That is, in the present embodiment, the flow channel axis of the particle flow channel is set to exist on a plane through which each optical axis of the light projecting element 3 and the light receiving element 4 passes, but is orthogonal to the plane. May be set.

  The heating unit 11 heats the gas in order to introduce the ambient air containing the particles P into the detection region 9, and serves as an air flow generator that generates an air flow for promoting the flow of the gas flowing in the particle flow path. Function. Specifically, the heating unit 11 is a heater resistor or the like, and is disposed in the particle channel in the present embodiment. That is, since the heating unit 11 heats the gas in the particle flow path to generate an upward air flow, it is preferable to install it in the lower part of the particle flow path as shown in FIG. Even when the heating unit 11 is not operating, the gas can pass through the particle flow path.

  A blower fan may be used to promote the flow of gas passing through the particle flow path. When the blower fan is not used, the particles P may detect the same particles a plurality of times just by drifting in the detection region 9. On the other hand, when the blower fan is used, the probability that the particles P pass through the detection region 9 according to the turbulent flow of the fluid or gas is high, so that the possibility that the same particles P are detected to drift can be reduced. For this reason, when using a ventilation fan, the heating part 11 may or may not be present.

  It is preferable to use a blower fan in order to promote the flow of gas flowing in the particle flow path. However, when changing the air volume for guiding the particles to the inlet 12 of the particle flow path, it is necessary to change the calculation setting of the particle size.

FIG. 3 is a diagram illustrating an image in which particles are detected in the detection region according to the embodiment.
The detection area 9 is an area where the optical axes of the light projecting element 3 and the light receiving element 4 intersect. In this detection area 9, light from the light projecting element 3 is scattered on the particle surface and received by the light receiving element 4. The Here, although the description will be made with a substantially spherical particle P, a strong scattering portion 14 and a weak scattering portion 15 exist according to the curvature of the particle P. Since the small particles as shown in (A) have a small curvature, the portion 14 with strong scattering is small, and the large particles as shown in (C) have a large curvature, so the portion 14 with strong scattering is large. The signal from the light receiving element 4 changes according to the intensity of the scattering, so that the size of the particle can be accommodated.

  FIG. 4 is a waveform diagram showing an example of converting a current signal output from the light receiving element according to the embodiment into a voltage signal.

  As an implementation condition, 0.05 g of 5 kinds of test powder 1 (fly ash) specified in JIS Z8901 was sprayed in a 1 cubic meter acrylic resin container, and the particle detector was operated after 45 seconds. It is the voltage signal after IV conversion acquired every 1 millisecond. Since it is immediately after the particles are dispersed, signals are observed overlapping. FIG. 5 is a simplified diagram showing the signal overlapped portions.

  That is, the signals observed in FIG. 4 can be interpreted as signals corresponding to four particles indicated by (a) (b) (c) (d) in FIG.

  In FIG. 5, for example, in (d), the original peak value should be regarded as the peak value VPC, but if the peak value VP corresponding to the peak falling start value V2 is read, appropriate data acquisition is not possible. become unable.

  FIG. 6 shows the signals (a) and (b) in FIG. 5 and the image of the passage of the particle detection region with respect to these signals.

An arrow 16 is an arrow indicating the passage direction of the particle group, and (a), (b), (c), (d), and (e) and the place where the particle P passes through the detection region 9 as time passes are illustrated. did.
In (a), the passage of the particle (a) starts, in (c) the scattered light from the particle (a) is maximized, and then the signal decreases over (d), and the passage of the particle (a) Starts (e), the signal starts to rise again. When the signals overlap in this way, there is a possibility that the signals cannot be read properly if they are read with the absolute value of the peak value VP.

  The present invention provides a means for reducing the risk of the signal becoming unreadable in this way.

  Next, the operation of the signal processing unit (analog signal processing unit and general-purpose MPU) will be described.

  FIG. 7 is a flowchart showing the operation of the signal processing unit according to the embodiment.

  As shown in the figure, the IV converter 5 first generates a voltage signal by converting the current output from the light receiving element 4 into a voltage. That is, the current signal output from the light receiving element 4 is converted into a voltage signal.

  Next, the amplifying unit 6 amplifies the voltage signal in a predetermined band.

  Thereafter, the AD conversion unit 7 generates digital data by performing digital conversion (AD conversion) on the voltage signal, which is an analog signal amplified by the amplification unit 6. That is, the AD conversion unit 7 generates time-series digital data in which the sensor signal indicating the output from the light receiving element 4 is digitized by sampling and quantization, and outputs the digital data to the calculation unit 8.

  Next, the procedure of the particle size calculation process will be described.

  FIG. 8 is a flowchart showing a particle size calculation process according to the embodiment.

  The procedure for this flowchart will be described more specifically.

  (Procedure 1) As the difference calculation 17 before and after, the difference between the signal (voltage value) immediately after and immediately before the signal (voltage value) at a predetermined time is obtained. For example, for the signal at time 6.300 seconds, the difference between the voltage value at 6.301 seconds and the voltage value at 6.299 seconds is obtained. In this way, the difference in signal (voltage value) is obtained for each time. The signal (voltage value) when the sign of the difference value 18 before and after this change from minus to plus is determined as “peak start value V1”, and the signal (voltage value) when the sign changes from plus to minus is determined. Determine “peak start value V2”.

  (Procedure 2) The difference between the “peak rising start value V1” and the “peak falling start value V2” is obtained and defined as “peak difference VD” (calculation 19 of “peak difference VD”).

(Procedure 3) The following determination is performed for “peak rising start value V1” to determine a correction coefficient (correction coefficient calculation 20).
(A) The correction coefficient is set to 1 when “peak starting value V1” ≦ 0.5V.
(B) When “peak rising start value V1”> 0.5 V, the correction coefficient is ““ peak rising start value V1 ”× 2 + 0.5”.

  This determination method is an example, and needs to be changed depending on the type and sensitivity of the sensor.

  (Procedure 4) A value calculated by multiplying the “peak difference VD” by the correction coefficient is defined as “deemed peak value VPC” (calculation 21 of “deemed peak value VPC”).

  (Procedure 5) A value obtained by squaring “deemed peak value VPC” is defined as “deemed volume conversion index NV” (calculation 22 of “deemed volume conversion index NV”). The “deemed volume conversion index NV” can be used to convert the data into data associated with the results of other measuring devices such as a dust sensor.

  (Procedure 6) When this result is converted into a histogram, the particle size calculation 23 is performed, the “deemed volume conversion index NV” is summed for each class value of the particle size, and is recorded as “volume conversion frequency FV” (“volume Calculation 24) of conversion frequency FV.

  In the sensor used in this example, the signal (voltage value) has a linear relationship with the particle size. Therefore, when calculating the volume frequency, the value based on the signal (“deemed peak value VPC”) is cubed and converted. did. In addition, although there is a type which catches with an area depending on a sensor, it is preferable to convert into the volume frequency by making the value based on a signal into the 1.5th power in that case.

  In other words, the “deemed peak value VPC” is a value corresponding to the peak value VP that would be observed when particles with overlapping signals pass through each particle even when signals based on a plurality of particles overlap. It is.

  The “deemed volume conversion index NV” is an index to be associated with the volume of each particle when creating a particle size distribution represented by volume frequency.

  The “volume conversion frequency FV” is a number obtained by integrating the “deemed volume conversion index NV” for each class value, and is a number for associating with the particle size distribution represented by the volume frequency.

  The results shown in FIG. 4, that is, 0.05 g of 5 types of test powder 1 (fly ash) defined in JIS Z8901 were dispersed in a 1 cubic meter acrylic resin container, and after 45 seconds to 55 seconds. Later, regarding the voltage signal obtained when the particle detector is operated, the “deemed peak value VPC” and the “deemed volume conversion index NV” obtained according to the above procedure are each incremented by 0.2V. When the “volume conversion frequency FV” is obtained by aggregation and a histogram is created, a distribution chart as shown in FIG. 9 is obtained.

  The following describes the appropriateness of this particle size calculation processing method.

The procedure similar to that shown in FIG. 9 was performed, and about 0.05 g of fly ash was applied, 45 seconds to 55 seconds, 4 minutes to 4 minutes 10 seconds, 8 minutes to 8 minutes 10 seconds after spraying. The subsequent detection results are summarized as shown in FIG. Note that the air volume for guiding the particles to the inlet 12 of the particle flow path was 0.03 m ³ / min.

  As for all the results, after 4 minutes to 4 minutes and 10 seconds, from 8 minutes to 8 minutes and 10 seconds, the “volume conversion frequency FV” from the larger “deemed peak value VPC” as time passes. There was a tendency to decrease.

  The reason for this is that the large particles fall first, but in order to show that these results are appropriate, the following will be described using the particle sedimentation rate equation.

  FIG. 11 is an example of fly ash particle size distribution according to the embodiment. The fly ash used here has a median particle size of 10 μm and a wide particle size range from 1 μm to 133 μm, based on the measurement result by a laser diffraction / scattering particle size distribution measuring apparatus.

  On the other hand, with respect to particles falling in a medium, it is known that a sedimentation velocity equation called a Stokes equation is given by the following equation 1 for spherical particles.

  This is an equation that has been used in the sedimentation method, which is a method for obtaining the particle size from the sedimentation velocity v of particles falling in the medium.

  Note that the drop time of the particles can be determined from the reciprocal of the settling velocity (fall velocity).

Here, each variable in Example 1 is as follows.
-Density of fly ash (ρ _p ): 2.0 g / cm ³
・ Air density (ρ ₀ ): 1.205 × 10 ⁻³ g / cm ³ (1 atm, 20 ° C.)
Air viscosity (η): 18.2 × 10 ⁻⁶ Pa · s (1 atm, 20 ° C.)
FIG. 12 is a diagram showing the relationship between the particle diameter and the drop time from a height of 1 m in the fly ash in the air according to the embodiment. The drop time of the particles was calculated by substituting the fly ash density, the air density (1 atm, 20 ° C.), and the air viscosity (1 atm, 20 ° C.) in Equation 1 for each particle size.

  FIG. 13 shows a graph in which FIG. 12 is taken into consideration in FIG.

  FIG. 13 is a diagram showing a particle size distribution that is arithmetically processed in consideration of falling from a height of 1 m in the fly ash in the air according to the embodiment.

  Specifically, in order to consider how many particles remain without dropping at each time, the consideration in FIG.

  Formula 2 calculates | requires ratio when each time (each elapsed time) is subtracted with respect to the fall time when the particle of each particle size in the particle size distribution falls according to the Stokes sedimentation velocity formula (Equation 1). This is a formula for multiplying the ratio by the particle size distribution of the volume frequency (however, when the sign of this ratio is negative, it is set to 0). The purpose of this multiplication is to obtain a particle size distribution assuming that the particles have fallen according to the Stokes settling velocity equation.

  If fly ash with a size of 10 μm and 45 seconds later, it is 5.5 (arbitrary unit) according to the calculation formula such as the following formula 3.

10 and 13, it can be confirmed that the distribution intensity decreases on the side where the “deemed peak value VPC” is larger with time, and the result of FIG. 10 appropriately represents the tendency.
The particle size distribution of fly ash is 1 to 133 μm (median particle size 10 μm) (measured value by a laser diffraction / scattering particle size distribution measuring device), which corresponds to falling from large particles.

  Table 1 summarizes the relationship between the “deemed peak value VPC” and the particle size based on the results of the above examples and the sidestream smoke of tobacco.

  Table 1 shows the relationship between the particle size based on the measured value by the laser diffraction / scattering particle size distribution measuring apparatus and the “deemed peak value VPC”.

Table 1 is an example of conversion of the “deemed peak value VPC” into a particle diameter, and is shown in FIG. R ² of the approximate straight line was 0.98, and it was confirmed that an appropriate correlation was obtained.

  Here, the particle diameter calculated from the “deemed peak value VPC” based on Table 1 and FIG. 14 is referred to as “calculated particle diameter”.

  Further, after the spraying of 0.05 g of fly ash, the detection result (actual measurement) of the sensor and the calculated value in consideration of the drop of the particles are compared for the result after 4 minutes.

  A flowchart of this processing and comparison procedure is shown in FIG. 15A.

Specifically, the following three results are compared.
“Result of particle size distribution calculation 25 after 45 seconds (actual measurement)”: Sensor detection result after 45 seconds to 55 seconds.
“Result of particle size distribution calculation 26 after 4 minutes (actual measurement)”: Sensor detection result after 4 minutes to 4 minutes and 10 seconds.
“Results of particle size distribution calculation 27 after 4 minutes (calculation)”: Results after 4 minutes calculated by multiplying the detection result of the sensor after 45 seconds to 55 seconds by the Stokes sedimentation velocity formula.

  A comparison of the results is shown in FIG. 15B.

  Comparing “after 45 seconds (actual measurement)” and “after 4 minutes (calculation)”, it is estimated that the degree of detection by the sensor decreases as the particle size increases. On the other hand, “after 4 minutes (actual measurement)” indicates that particles of 10 μm or more still exist. However, “4 minutes later (calculation)” and “4 minutes later (actual measurement)” have the same calculated particle diameter that maximizes the volume conversion frequency FV (particle diameter of 6.6 μm in the figure). By comparing the detection results of these sensors with the calculation results, it is determined that the particles tend to fall according to the settling velocity equation as a whole, but some particles are still floating in the air. be able to.

  In addition, although the particle size from which the volume conversion frequency FV becomes the maximum is compared here, this comparison method is an example of embodiment of this invention.

  As another example, Ishimatsuko's example will be described.

FIG. 16 summarizes the detection results of 0.05 g Ishimatsuko after 45 seconds to 55 seconds, 4 minutes to 4 minutes and 10 seconds, and 8 minutes to 8 minutes and 10 seconds after spraying. . Note that the air volume for guiding the particles to the inlet 12 of the particle flow path was 0.03 m ³ / min.

  In any result, almost no particles were detected after 4 minutes to 4 minutes and 10 seconds and after 8 minutes to 8 minutes and 10 seconds. This is because the particle size distribution of Ishimatsu is as large as 19 to 59 μm (median particle size 32 μm) (measured value by a laser diffraction / scattering particle size distribution measuring device), and falls down completely. As in the case of fly ash, this will be described below.

  FIG. 17 is an example of the particle size distribution of Ishimatsuko according to the embodiment. The stone mushroom used here has a median particle size of 32 μm and a particle size range of 19 μm to 59 μm based on the measurement result by the laser diffraction / scattering particle size distribution measuring device.

FIG. 18 is a diagram showing the relationship between the particle size and the drop time from a height of 1 m in the air stone mushroom according to the embodiment (the density of the stone mushroom is 1.1 g / cm ³ ).

  FIG. 19 shows a graph in which FIG. 18 is considered in FIG.

  The consideration of FIG. 18 here is synonymous with the consideration of FIG.

  That is, FIG. 19 is a diagram illustrating a particle size distribution that is arithmetically processed in consideration of falling from a height of 1 m in the air stone mushroom according to the embodiment.

  In FIG. 16, the phenomenon in which particles are hardly observed after 4 minutes to 4 minutes and 10 seconds and after 8 minutes to 8 minutes and 10 seconds is the same as in FIG. .

FIG. 20 shows the distribution of the assumed peak value VPC detected and calculated in a 1 cubic meter acrylic resin container in the fly ash (0.05 g) and the stone matsuko (0.05 g) in the air according to the embodiment. FIG. The air volume of the blower fan is 0.03 m ³ / min. Here, fly ash and Ishimatsu were sprayed at the same time.
FIG. 21 shows the result of fly ash (0.05 g) (FIG. 10) and Ishimatsu regarding the distribution of the assumed peak value VPC detected and calculated in the 1 cubic meter acrylic resin container according to the embodiment. It is the figure which synthesize | combined the result (FIG. 16) of a child (0.05g) (all are the airflows of a ventilation fan 0.03m < ³ > / min).

  An example (FIG. 20) in which fly ash and stone matsuko were simultaneously poured was the same as the result obtained by adding the individual results (FIG. 21), and the effects of the present invention could be expressed.

  As described above, the effects of the present invention for calculating the particle size after obtaining the difference between the “peak rising start value V1” and the “peak falling start value V2” can be explained by Examples 1 to 3.

  FIG. 22 shows an example of an air purifier according to the embodiment.

DESCRIPTION OF SYMBOLS 1 Particle measuring device, 2 Particle detection sensor, 3 Light projecting element, 4 Light receiving element, 5 IV conversion part, 6 Amplification part, 7 AD conversion part, 8 Calculation part, 9 Detection area | region, 10 Housing | casing, 11 Heating part, 12 Particle channel inlet, 13 Particle channel outlet, 14 Strongly scattered portion, 15 Slightly scattered portion, 16 Arrow indicating the passage direction of particle group, 17 Calculation of difference before and after, 18 Difference value before and after, 19 Calculation of “peak difference VD”, calculation of 20 correction coefficient, calculation of 21 “deemed peak value VPC”, calculation of “deemed volume conversion index NV”, calculation of particle size, calculation of 24 “volume conversion frequency FV” 25 Particle size distribution calculation after 45 seconds (actual measurement), Particle size distribution calculation after 264 minutes (actual measurement), Particle size distribution calculation after 274 minutes (calculation), P particle, M air cleaner, V1 peak start to rise Value of the V2 peak Rising start value, VD peak difference, VP peak value, VPC considered peak value, NV regarded reduced volume index, FV in terms of volume frequency

Claims (2)

A particle measuring device for measuring the particle size of particles contained in a fluid that is gas or liquid,
A particle detection sensor having a light projecting element that projects light to a detection region, and a light receiving element that receives scattered light of light scattered by the particles located in the detection region;
For the waveform corresponding to the particle included in the sensor signal indicating the output from the light receiving element, a difference between the peak start value and the peak start value and a coefficient determined by the peak start value are used. A particle measuring apparatus that calculates a particle diameter based on a calculation. An air cleaner comprising the particle measuring device according to claim 1 .

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