KR101180588B1 - Detecting apparatus for particle in the air - Google Patents

Abstract

An object of the present invention is to provide an apparatus in which the dropping dust does not stay in the collecting portion for collecting the gas including the dropping dust.
The collection part 3 which collects the gas containing the particle | grains which descend | falls the air, and the measurement part 26 which measures the particle | grains of the air collected by this collection part 3 are provided, and the collection part 3 is sheath air The sheath air generating means 11 which generate | occur | produces, and the impactor 21 which performs separation by inertia force between the collection part 3 and the measurement part 26 is arrange | positioned.

Description

Airborne particle detection device {DETECTING APPARATUS FOR PARTICLE IN THE AIR}

The present invention relates to an airborne particle detection apparatus.

In order to expand the dust collection range of floating descent dust, the funnel which introduce | transduces gas containing falling dust may be installed in a measurement part (refer patent document 1).

Japanese Patent Application Laid-open No. Hei 10-123043

However, when the particles (falling dust) to be measured are attached to the inclined portion of the funnel, the attached particles do not reach the measurement portion, and therefore the particles in the air cannot be accurately measured by the measurement portion.

Therefore, an object of the present invention is to provide an apparatus in which the falling dust does not stay in the collecting portion for collecting the gas including the falling dust.

This invention is equipped with the collection part which collects the gas containing the particle | grains which lower | hangs air, and the measurement part which measures the particle | grains of the air collected by this collection part. The sheath air generating means for generating the sheath air in the collecting section is provided, and an impactor for performing separation by inertial force is disposed between the collecting section and the measuring section.

According to the present invention, the sheath air eliminates the case where the particles to be measured adhere to and remain in the collection unit. Moreover, since the flow rate which can be measured can flow into a measurement part by removing the excess gas by sheath air with an impactor, the measurement precision of the measurement object particle | grains improves.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic perspective view which decomposes | disassembles and shows the airborne particle detection apparatus of 1st Embodiment of this invention.
2 is a schematic plan view of the funnel.
3 is a schematic view for explaining the difference between the normal use method of the impactor and the use method of the present embodiment of the impactor.
4 is a schematic view for explaining the effects of the sheath air generating means and the impactor according to the present embodiment.
5 is a schematic perspective view of a funnel of a second embodiment.
6 is an enlarged cross-sectional view of a part of the sheath air generating means of the second embodiment;
7 is a schematic perspective view of a funnel of a third embodiment.
8 is a schematic plan view from above of the funnel in a cross-sectional view shown by the dashed-dotted line in FIG. 7.
9 is a schematic diagram for explaining retention in a funnel of an assembler;
10 is a schematic diagram showing a method of measuring a assembler by a conventional apparatus.
11 is a schematic diagram showing a method of measuring a assembler by a conventional apparatus.

1 is a schematic perspective view of an airborne particle detection apparatus 1 according to a first embodiment of the present invention, and FIG. 2 is a schematic plan view of the funnel 3 as a collecting unit. However, in FIG. 1, the component of the airborne particle detection apparatus 1 is disassembled and shown. The airborne particle detection apparatus 1 consists of the funnel 3, the sheath air generating means 11, the impactor 21, and the measurement part 26. As shown in FIG.

The measurement object is a particle (hereinafter referred to as "falling dust") that drops in the air. In order to inhale air containing this falling dust, a blower or a pump is provided inside the measurement unit 26. At the time of the measurement of the falling dust, the air containing the falling dust is sucked into the measurement part 26 through the funnel 3 and the impactor 21 from vertically upward by driving this blower and a pump.

The funnel 3 collects air containing falling dust. The cone-shaped member 4 which opens vertically upward and the oval of the cone-shaped member 4 consist of the cylindrical member 5 connected below. In the present embodiment, the falling dust is handled by being divided into particles (PS) (first particles) having a relatively small diameter and granules (PL) (second particles) having a relatively large diameter as described below. For this reason, two types of particle | grains of these microparticles | fine-particles PS and granules PL fall to the cone-shaped member 4 opened toward a perpendicular upper direction. The fine particles PS and the granules PL falling from above collide with the inner wall 4a of the cone-shaped member 4 and then are introduced into the lower cylindrical member 5 falling out along the inner wall 4a. do.

The falling dust collected by the funnel 3 is ideally transported through the path to the measuring section 26 without delay. This is because the falling dust retained on the inner wall 4a of the cone-shaped member 4 is not measured by the measuring unit 26, so that the falling dust cannot be accurately measured.

The cause of the retention of the falling dust in the funnel 3 is the adhesion of the falling dust. If grease adheres, for example, to falling dust, it will collide with the inner wall 4a of the cone-shaped member 4, and falling dust will remain in the position, and will not fall below. In addition, even if the falling dust is transported to the cylindrical member 5 without being attached to the inner wall 4a of the cone-shaped member 4, when it adheres to the inner wall of the cylindrical member 5 and stays at the position. I think too. In these cases, defects in falling dust to be measured are generated.

In this embodiment, the sheath air generating means 11 is provided in order to prevent the retention of falling dust on the inner wall of the cone-shaped member 4 or the cylindrical member 5. The sheath air generating means 11 is provided around the entire circumference of the opening end 4b of the funnel 3 (collection part), so that clean air is formed so that a uniform layer along the inner wall 4a of the cone-shaped member 4 is formed. It is a mechanism to discharge (clean air). The mechanism is mainly composed of a nozzle 12, a supply pipe, and an air pump 13.

Specifically, the plurality of converging nozzles 12 face the tip 12a downward at equal intervals in the circumferential direction to the upper opening end portion 4b of the cone-shaped member 4 and the inner wall of the cone-shaped member 4. It is installed so as to follow (4a). The air pump 13 is pressurized with clean air, and an annular tube 15 provided to surround the opening end 4b is connected to the main air supply pipe 14 for supplying the pressurized air. The end of each nozzle 12 is connected to the branch pipe 16 branching from 15. For this reason, the pressurized air from the air pump 13 is supplied to each nozzle 12 through the main air supply pipe 14, the annular pipe 15, and the branch pipe 16, and the front end of each nozzle 12 ( From 12a, pressurized air is blown out along the inner wall 4a of the cone-shaped member 4.

When conical air 12c having a predetermined injection angle is injected from the nozzle tip 12a around the axis 12b of the nozzle 12 as shown in FIG. 1, each conical air as shown in FIG. 12c overlap each other and spread along the inner wall 4a of the cone-shaped member 4 to form a uniform laminar flow flowing into the cylindrical member 5. In FIG. 2, since the injection angle from the nozzle tip 12a is relatively narrow, the laminar flow due to air is not formed near the opening end 4b, and the portion where the inner wall 4a of the cone-shaped member 4 is exposed. However, this exposed portion can be reduced by widening the injection angle from the nozzle tip 12a or by increasing the number of the nozzles 12. In this manner, the laminar flow covering the entire inner wall 4a of the cone-shaped member 4 can be formed.

Thus, by forming the laminar flow by air to a uniform thickness along the inner wall 4a of the cone-shaped member 4, the falling dust falling into the cone-shaped member 4 from the vertical upper part is applied to the laminar flow by this air. Thereby, it flows into the cylindrical member 5, without attaching to the inner wall 4a of the cone-shaped member 4. As shown in FIG.

In this case, not only the inner wall 4a of the cone-shaped member 4 but also the laminar flow by air is formed in the inner wall surface of the path from the funnel 3 as a collection part to the air inlet 26a of the measurement part 26, Ensure laminar flow is maintained during the measurement of falling dust. In order to maintain laminar flow, it is such that the critical ray nozzle number Re is not exceeded in the path from the funnel 3 to the air inlet 26a of the measurement unit 26 (including the iris (reducer)). In particular, when the flow rate of the laminar flow increases or the thickness of the laminar flow increases due to the decrease in the cross-sectional area in the cylindrical member 5, the critical ray nozzle number Re increases. The number of nozzles 12, the shape of the nozzle tip 12a, and the like so that laminar flow is formed and maintained on the inner wall of the path from the cylindrical member 5 to the air inlet 26a of the measurement unit 26, The flow rate of the clean air blown off from the nozzle tip 12a is set.

Thus, by forming and maintaining the laminar flow on the inner wall surface of the path from the funnel 3 to the air inlet 26a of the measurement part 26, the fall dust adheres to the inner wall 4a of the funnel. Thereby, even if falling dust has adhesiveness, the defect of the falling dust of a measurement object can be prevented. In addition, in order to impart a protective layer effect due to the density difference, it is preferable to use a gas heavier than air to form the laminar flow.

Conventionally, a particle sensor (also called a particle counter or a dust meter) is generally used as a method of measuring suspended dust (also called "particle") existing in the environment. In order to measure cleanliness, such as a clean room, these often have the measurement range set to the particle | grains of 1-5 micrometer size mainly ("microparticles" hereafter). In the manufacturing process of a semiconductor, since the said fine particle directly affects a production yield, it can be called a reasonable setting value. However, there exist many processes in which the particle | grains of a 5-100 micrometer size (henceforth "assembly") become a defect with respect to a product. For example, the solidification of solder fume in electronic circuits may result in contaminants (contamination) by dropping into the product, or the coarse particles attached to the painted surface of automobiles to cause "contaminants", and also in the secondary battery manufacturing process. Defects due to mixing of the metal pieces in the sheet. In the present invention, such a coarse particle generally drops (falls) in the air, so that it is called "falling dust" different from floating dust existing in the environment.

As a method for effectively measuring the granulator (falling dust) which has not been measured as a particle sensor until now, it is used to change the measurement range of the existing particle sensor from relatively small diameter particles to relatively large diameter granulators. Is efficient (technically readily possible), but there are some problems.

For example, when a coarse particle is generated on a product and attempts to capture the state of occurrence and drop with a particle sensor, the coarse particle (falling dust) is less likely to be affected by the gas flow (especially when it is a few tens of micrometers in size). It shows the behavior of falling. Therefore, the measurement part of a particle sensor is set in the lower part of a generation source. However, since the measurement unit of the particle sensor is generally several mm to several tens of mm, it is necessary to set a funnel (probe) or the like that confines the entire body including the granulator (falling dust) to be measured to the measurement unit. If this is to be solved by the prior art, the granulator (falling dust) falls and adheres to the funnel and stays in place. This is due to the inclination of the funnel, the unevenness or the cohesiveness of the coarse grain (falling dust) itself (or the sticky thing attached to the coarse grain (falling dust)). This makes it impossible to pass all of the granulators (falling dust) to be measured to the measurement unit, so that accurate measurement cannot be performed. For example, as shown in Fig. 9, the coarse coarse particles (falling dust) do not stay in the funnel and are guided to the measurement unit. Thus, there existed a problem (1st problem) that it was not able to measure correctly because of the retention of the coarse particles (falling dust) which generate | occur | produces in collection | collection parts, such as funnels, when a coarse particle (falling dust) falls.

Moreover, even if the measurement part adjusts the conduction by funnel etc. so that it may become the flow velocity suitable for measurement at the inlet, the flow volume will be restrict | limited by the measurement part. The flow rate is limited in the measurement unit because the measurement unit is designed for the limited flow rate. Thereby, a blowback of the gas which enters into a funnel, or the fall of the measurement precision by causing exceeding the flow velocity of the calibration range by excess flow volume, etc., arises. For example, in the case where the downflow of air toward the funnel is 1000 L / min as shown in FIG. 10, the case where the flow is limited to 20 L / min at the inlet of the measuring unit is as shown at the top of FIG. 11. Air overflows from the funnel (collection). On the other hand, if all flows to a measurement part so that it may not overflow, as shown in the lower part of FIG. 11, the flow velocity in a measurement part will become large too much and abnormal measurement will generate | occur | produce. Thus, the flow rate of the measurement part is limited, and since the flow rate of air including the granulator (falling dust) from the collection part is limited to this flow rate, there is also a problem (second problem) that it cannot be measured accurately.

In contrast, according to the present embodiment, the first problem can be solved by the first design including the sheath air generating means 11.

By the way, when flowing the sample liquid suspended in the liquid in the liquid in the biological analysis or the like, the liquid is wrapped so as to surround the sample liquid using hydrodynamic characteristics (laminar flow does not mix) so that the sample liquid does not directly contact the measuring instrument. Shedding is done. The liquid surrounding this sample liquid is called a sheath liquid and is distinguished from the sample liquid. The flow of the sample liquid is called sample flow, and the flow of the sheath liquid is called sheath flow. The above describes the way of thinking about the flow of liquid in biological analysis and the like. In the following, clean air (gas) flowing through the inner wall 4a in the form of layers so as not to adhere to the inner wall 4a of the cone-shaped member 4 is referred to as "cis air" and the laminar flow formed by the clean air. It is called "sheath." In addition, a layered sheath air is called "a sheath air layer."

This is explained in detail using FIG. 4, and FIG. 4 is a schematic diagram explaining the effect of the sheath air generating means 11 of this embodiment and the impactor 21 mentioned later with an image.

The measurement target air is sucked downward through the center, the sheath flows so as to surround the measurement target air, and the sheath air layer is formed. In FIG. 4, a shadow is given to this sheath air layer. Coarse particles PL and fine particles PS exist in the air to be measured. The sheath air layer does not move in a direction different from the flow direction of the granulators PL and the particles PS. As a result, the coarse particles PL and the fine particles PS are prevented from adhering to the inner wall of the funnel 3 (that is, the inner wall 4a of the cone-shaped member), thereby preventing defects in the particles to be measured. Here, although the direct measurement object is the granulator in air (air), the air containing the granulator which is this measurement object is called "measurement object air."

Next, a design (second design) for the second problem will be described. This is an idea of how to use the impactor. The upper part of FIG. 3 is a schematic diagram for demonstrating the normal use method of the impactor 21, and the lower part of FIG. 3 is a schematic diagram for demonstrating the use method of this embodiment of the impactor 21. As shown in FIG.

The impactor 21 is composed of a straight pipe 23 which guides the sheath air and the measurement target air from the funnel 3, and a suction port (exhaust) disposed evenly around the entire straight pipe 23, It is to perform separation. In addition, since it is difficult to show the suction port uniformly arrange | positioned around the periphery of the straight pipe 23, in FIG. 3, it is one suction pipe 24 which branches this suction port from the straight pipe 23, and also FIG. 1, FIG. In 4, it shall be represented by two suction pipes 24 of right and left.

The flow in the tube is actually uniform, like a rotor with its center line as its axis of rotation. For this reason, with respect to the separation of the surplus air containing the sheath air and the fine particles (PS), the suction pipe 24 is provided in two places on the left and right with respect to the straight pipe 23, or in only one place. Differences occur in the air flow where the excess air containing (PS) is sucked in and where the excess air containing sheath air and fine particles (PS) is not sucked. That is, the suction pipe of the surplus air containing the sheath air and the fine particles PS must be uniform around the pipe of the straight pipe 23. Since it is practically difficult to show a uniform suction tube around the tube, one suction tube 24 as shown in FIGS. 1 and 4 or as two suction tubes 24 as shown in the lower part of FIG. Represented by.

First, the normal use method of the impactor 21 is demonstrated. In the upper end of FIG. 3, the straight pipe 23 which introduces the sheath air and the measurement object air is arrange | positioned in the up-down direction in the storage box 22 in the state which downward is open. The upper end of the straight pipe 23 is connected to the cylindrical member 5. The suction pipe 24 branching from the straight pipe 23 in the horizontal direction is exposed to the outside through the wall of the storage box 22. The suction pipe 24 is connected to the measurement unit 26 through the air suction passage 25.

The blower or the fan inside the measurement unit 26 is operated to suck the measurement target air into the measurement unit 26 through the suction pipe 24. Then, the granulator PL and the fine particles PS are sucked into the straight pipe 23 from above the measuring instrument. In the coarse particles PL and the fine particles PS, the inertia force is different, and the coarse particles PL have a larger inertia force than the fine particles PS. Due to the difference in inertia force, the granulator PL is dropped by dropping directly below the straight pipe 23 without being bent, and only the fine particles PS are bent from the straight pipe 23 into the suction pipe 24 to be measured. A). In this way, the granules PL are removed by the inertial force, and only the fine particles PS are guided to the measurement unit 26 to measure the number of fine particles PS.

In addition, in this embodiment, it is an object not to measure microparticles | fine-particles PS but to measure the granulator PL larger in diameter than microparticles | fine-particles PS. For this reason, the normal use method of the impactor 21 as shown in the upper part of FIG. 3 cannot be used. Therefore, it is as shown in the bottom of FIG. That is, the lower end part of the straight pipe 23 is exposed to the outside through the lower wall of the storage box 22, and is connected with the measurement part 26 through the air suction passage 25. As shown in FIG. The suction pipe 24 penetrates the horizontal wall of the storage box 22 and is exposed to the outside, and is connected with the blower 28 (or a fan) through the air suction passage 27. The blower 28 is for aspirating excess air including most of the sheath air and the fine particles PS.

In this case, due to the difference in the inertia forces of the two kinds of particles PS and PL, the relatively large diameter granulator PL does not bend, but falls directly inside the straight pipe 23 to measure the measuring device 26. The fine particles PS having a relatively small diameter are excluded by the blower 28 through the suction pipe 24 and the air suction passage 27. As described above, in the present embodiment, the separation method by the inertia force performed by the impactor is optimized using the reciprocal.

Where the separation method by the impactor 21 of this embodiment is favorable, the blower 28 discards the excess air containing the majority of the sheath air and the particulate matter PS, and reduces the amount of air flowing into the measuring unit 26. It is in the point that can be made. In the measurement unit 26, in order to measure the number of particles per suction flow rate, generally, the flow rate is narrowed even in the case of separation by inertial force. This flow rate stop is effectively performed by the blower 28 in this embodiment.

Referring again to the operation of the impactor 21 of the present embodiment in FIG. 4, when the measurement target air and the sheath air come to the position of the suction pipe 24, most of the sheath air and the fine particles PS are removed by the suction pipe 24. Since the excess air included is sucked in, the thickness of the sheath air layer decreases, but the sheath air layer is held up to the inlet of the measurement unit 26. In this way, by separating and discarding the majority of the sheath air and the surplus air containing fine particles with the impactor 21, the flow rate of the measurement target air can be reduced to the limited flow rate of the measurement unit 26. Moreover, the defect of the coarse particle to be measured can be prevented.

Moreover, not all the sheath air can be sucked by the suction pipe 24, and a small amount of sheath air is also required for the inner wall from the suction pipe 24 to the air inlet of the measurement unit 26. Therefore, a small amount of sheath air enters the measurement unit 26 together with the measurement target air. Since sheath air does not exist initially in an environment, the measurement object air will increase by the amount of sheath air, and it may become the error of a measured value. However, since it is possible to measure in advance how much sheath air enters the measurement unit together with the measurement target air, the measured value can be made accurate by correcting the measured value in consideration of the amount of the measured sheath air.

Next, the design method of the airborne particle detection apparatus is demonstrated. Both the supply amount of the sheath air and the suction amount from the suction pipe 24 of the impactor 21 have a function of adjusting the flow rate (supply amount, suction amount). As a result, the flow rate of the sheath air layer can be controlled to be equal to or less than the critical ray nozzle number, so that the sheath air layer can be maintained in a horn shape.

The appropriate values of the size of the funnel, the dimensions of the sensor inlet (the air inlet of the measuring section 26) and the amount of supply of the sheath air will be specifically discussed. First, from the flow rate in the case of not applying the present invention, when the sensor allowable amount (limit flow rate of the measurement unit 26) is 130 L / min, for example, the flow rate of the funnel 3 as the collection unit is equal to this value. It is necessary to make it the same 130L / min.

In contrast, how the flow rate in the case of applying the present invention is calculated. For example, when the maximum flow velocity (1/2 to 1/3 of the speed of sound is realistic) is flowed into a φ7 mm tube, the weight loss by the suction tube 24 of the impactor 21 can be reduced to 300 L / min. Make sure On the other hand, it is set as the flow velocity when the thickness of the sheath air layer is 5 mm and the critical ray nozzle number is 500,000 (the value is applied because the plate is known to be about 500,000). The funnel is a funnel with a diameter of 200 mm and an angle of 45 °. And, it is said that the critical flow rate is reached at the narrowest part of the funnel. At this time, it is assumed that the sheath air generating means 11 increases the sheath air to 34 L / min (MAX value). When the sensor allowable amount is 30 L / min, which is the same as in the case where the present invention is not applied, the flow rate of the funnel is 30 + 300-34 = 296 L / min. In this way, it became possible to always measure with high precision how long the granulator is in the volume of 1 ft ^ 3. In addition, the particle sensor (measuring unit) counts the number of particles per suction flow rate by irradiating laser light to the measurement target air containing the particles and receiving the reflected light from the particles.

Next, it is examined whether the formation of the sheath air layer is possible. When the suction amount of the impactor 21 by the suction pipe 24 is smaller than the supply amount of the sheath air, the supply of the sheath air is excessive, and an appropriate amount of the measurement target air is not introduced into the measurement unit 26. In this case, therefore, the measurement target air is overflowed (the setting is not performed in such a manner).

The suction amount (set flow rate) by the suction pipe 24 of the impactor 21 is larger than the supply amount (set flow rate) of the sheath air. Since the sheath air is supplied toward the impactor 21, when the suction amount by the suction tube 24 of the impactor 21 and the supply amount of the sheath air are the same amount, the entire amount of the sheath air is supplied to the suction tube 24 of the impactor 21. Aspirated. By increasing the amount of suction by the suction pipe 24 of the impactor 21, it is possible to inhale the measurement target air in addition to the sheath air, so long as the fluid forming the sheath air layer does not exceed the number of critical ray nozzles. The layer is not broken. Therefore, even if it is accompanied by a cross-sectional change, if it is below the critical ray nozzle number, a sheath air layer will not be destroyed.

Here, the effect of this embodiment is demonstrated.

According to this embodiment, the funnel 3 (collection part) which collects air (gas) containing the particle | grains which descend | falls in air, and the measurement part 26 which measures the particle | grains in the air collected by this funnel 3 And having the sheath air generating means 11 for generating the sheath air in the funnel 3 and arranging the impactor 21 for separating the funnel by the inertial force between the funnel 3 and the measurement unit 26. The flow rate that can be measured by eliminating the particles of the measurement target (detection target) attached to the funnel 3 and staying with the sheath air, and eliminating the excess air supplied as the sheath air with the impactor 21. Can flow into the measurement unit 26, so that the measurement accuracy of the particle to be measured (particle to be detected) is improved.

According to the present embodiment, the sheath air generating means 11 is installed around the entire circumference of the opening end 4a of the funnel 3 (collection part), so that a uniform layer along the inner wall 4a of the funnel 3 is formed. Since it is a mechanism which discharges clean air (clean air) or clean air so that it may form, it is possible to form a sheath air layer on the entire inner wall 4a of the funnel 3.

According to the present embodiment, the impactor 21 includes a straight pipe 23 for guiding the sheath air and the measurement target air (air including the particles to be measured) from the funnel 3 (the collecting portion), and the straight pipe 23. It consists of a suction port (suction tube 24) evenly disposed around the entire circumference, and guides only the granulator PL (second particle) to the measurement unit 26 by inertial force, and the majority of the sheath air and the fine particles (PS Since excess air including the (first particle) is excluded from the suction port, it is possible to efficiently discharge the excess air containing the sheath air and the fine particles to be measured.

5 is a schematic perspective view of the funnel 3 of the second embodiment, and FIG. 6 is an enlarged cross-sectional view of a part of the sheath air generating means 11 of the second embodiment. The same reference numerals are given to the same parts as in Figs. 1 and 2. In addition, the number of the air blowing holes 35 differs between FIG. 5 and FIG.

In the second embodiment, the sheath air generating means 11 includes an air pump 13, a main air supply pipe 14, a ring-shaped air reservoir 31, and an air blowing hole 35.

The parts different from the first embodiment will be mainly described. Instead of the nozzle of the first embodiment, the ring-shaped air reservoir 31 and the air blowing hole 35 are formed in the second embodiment. First, from the cone-shaped member 4 at a predetermined height lower than the upper plate member 32 and the opening end portion 4b which are provided with a predetermined width extending outward from the opening end 4b of the cone-shaped member 4 in the radial direction outward. Cone opposed to the lower plate member 33 extending in the same width as the predetermined width toward the radially outer side, the outer peripheral member 34 having a curved shape connected to both the members 32 and 33, and the outer peripheral member 34. The ring-shaped air storage part 31 whose cross section is a parallelogram from the shape member 4 is comprised. This ring-shaped air storage part 31 is formed in the periphery of the opening edge part 4b of the cone-shaped member 4.

The cone-shaped member 4 opposite to the outer circumferential member 34 includes a plurality of air blowing holes 35 arranged along a line from the opening end 4b of the cone-shaped member 4 toward the cylindrical member 5. The heat through which the plurality of air blowing holes 35 are arranged is provided at equal intervals in the circumferential direction of the cone-shaped member 4 as shown in FIG. 5.

As shown in FIG. 6, clean air pressurized by the air pump 13 is introduced into the ring-shaped air reservoir 31 through the main air supply pipe 14. As a result, clean air is blown into the cone-shaped member 4 from the air blowing hole 35. The air blown into this cone-shaped member 4 is for generating the sheath which flows in layer form along the inner wall 4a of the cone-shaped member 4. However, if only the air blowing hole 35 is drilled in the cone-shaped member 4, the air is blown in the direction orthogonal to the wall of the cone-shaped member, and the inner wall 4a of the cone-shaped member 4 is opened. It does not become a following flow. Therefore, as shown in FIG. 6, the air blowing hole 35 is provided with the guide 36 which regulates the blowing direction of the air, and the air flows from each air blowing hole 35 into the inner wall of the cone-shaped member 4 ( The air blown out along 4a) and the blown air are joined to form a sheath that covers the entirety of the inner wall 4a of the cone-shaped member 4 so that a sheath air layer is formed.

In this way, the air blown out from each air blowing hole 35 merges and flows along the inner wall 4a of the cone-shaped member 4 and covers the whole of the inner wall 4a of the cone-shaped member 4. The sheath air layer is formed on the inner wall 4a of the cone-shaped member 4.

FIG. 7 is a schematic perspective view of the funnel 3 of the third embodiment, and FIG. 8 is a schematic plan view of the funnel 3 seen from above in a cross-sectional view shown by a dashed-dotted line in FIG. 7. The same reference numerals are given to the same parts as in Figs. 1 and 2. In addition, the number of the air introduction holes 42 differs between FIG.7 and FIG.8.

In the first and second embodiments, clean air is used as the sheath air. In the third embodiment, the same air as the measurement target air is conveniently used as the sheath air. For this reason, an air pump and a main air supply line may be unnecessary.

The sheath air generating means 11 of 3rd Embodiment is the pin 41 which provided in multiple at equal intervals in the circumferential direction of the cone-shaped member 4 in the vicinity of the opening edge part 4b of the cone-shaped member 4, and It is mainly composed of an actuator (not shown) which drives the funnel 3 to rotate about its axis. That is, the c-shaped cutouts are inserted at equal intervals in the circumferential direction near the opening end 4b of the cone-shaped member 4, and the pins 41 are formed by opening the cutouts outward. After the cut-out part is opened, the air introduction hole 42 is formed. The funnel 3 supports to rotate about its axis.

Now, when the funnel 3 is rotated counterclockwise by the actuator in FIG. 8, the cone-shaped member (through the air introduction hole 42 drilled in the cone-shaped member 4 for formation of the pin 41). 4) Air of the outer circumference (the same air as the measurement target air) is supplied into the cone-shaped member 4. In FIG. 8, the flow of air supplied into the cone-shaped member 4 at this time is shown by the arrow.

In this case, air supplied from each air introduction hole 42 into the cone-shaped member 4 flows in a spiral form along the inner wall 4a of the cone-shaped member 4, and these helical flows It is a sheath which joins and covers the whole inner wall 4a of the cone-shaped member 4, and the position of the air introduction hole 42 or the fin 41, the air introduction hole 42 or the fin so that a sheath air layer is formed. The shape of 41 is set.

In this manner, in the vicinity of the open end 4b of the cone-shaped member 4, a plurality of pins 41 are provided around the cone-shaped member 4 at equal intervals, and a hole opened for forming the pin is formed. By rotating the funnel 3 as an air introduction hole, the air supplied from each air introduction hole 42 to the inside of the cone-shaped member 4 causes the inner wall 4a of the cone-shaped member 4 to form a layer. The burning sheath becomes a sheath, and the sheath air layer is formed in the whole inner wall 4a of the cone-shaped member 4.

Since the ratio of the coarse particles contained in the measurement target air is small, it is considered that even if the same air as the measurement target air is used as the sheath air, it does not affect the measured value. In this sense, clean air does not necessarily need to be used even in the first and second embodiments.

Finally, it is thought that the airborne particle detection apparatus of this invention is arrange | positioned in each location of the manufacturing line of secondary batteries, such as a lithium ion secondary battery, for example. As a result, the occurrence of problems caused by the coarse particles attached to the product can be detected without undergoing an inspection process, thereby improving the yield of production and reducing the cost thereof.

3: funnel (collection)
11: sheath air generating means
21: impactor
24: suction pipe (suction port)
26: measuring unit

Claims (3)

A collecting unit for collecting a gas including particles that lower the air;
It is provided with the measuring part which measures the particle | grains in the air collected by this collection part,
An airborne particle detection device, characterized in that the collecting unit includes a sheath air generating means for generating the sheath air, and an impactor for performing separation by inertial force between the collecting unit and the measuring unit. The airborne particle detection device according to claim 1, wherein the sheath air generating means is a mechanism that is installed around the entire open end of the collecting portion and discharges air so that a layer along the inner wall of the collecting portion is formed. The method according to claim 1 or 2, wherein when the particles dropping the air weight are composed of first particles having a relatively small diameter and second particles having a relatively large diameter,
The impactor is composed of a straight pipe that guides the gas including the sheath air and the particles to be measured from the collecting unit, and a suction port that is evenly disposed around the entire circumference of the straight pipe,
An airborne particle detection device, characterized in that only the second particles are guided to the measurement unit by inertial force, thereby excluding excess air including the sheath air and the first particles from the suction port.

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