JP2000035383A - Dust-collecting device for cyclon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a response speed in the case of changing of fine particle concentration from a high concentration to a low concentration in the case of using for measuring the concentration or the like of fine particles by intermittently sucking a gas to be measured into a cyclon. SOLUTION: A dust-collecting device used for measuring the suspending dust in a clean room is provided with, for example, a cyclon 1 for collecting dust by sticking fine particles to an inner wall, a counter 2 using a CCD or the like for measuring the number of fine particles being sucked by a dust- collecting filter 3 by a pump 4, and a blower 5 that is controlled by a controller 6. When dust-collecting operation is started, dust-collecting operation continuous through a set time, for example, until the number of count reaches a given value with the counter 2. During that period, the blower 5 performs intermittent operation for performing suction for a constant operation time and then intermittent operation stop for a constant pause time. The operation time and pause time are set so that dust can be collected efficiently and a fine particle stuck to the inner wall of the cyclon 1 may be removed during the suspension of suction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cyclone dust collecting apparatus for collecting airborne dust in a clean room and particles in flue gas, and more particularly to improvement of response characteristics.

[0002]

2. Description of the Related Art The present applicant has proposed a cyclone dust collecting apparatus in Japanese Patent No. 2754941 or the like. Such a dust collector, for example, analyzes floating dust in a clean room, identifies a source of dust to improve the yield of semiconductors, or counts particles in flue gas to reduce air pollution. Used to take countermeasures. The conventional cyclone dust collecting apparatus is configured such that when the dust collecting operation is started, the operation is continued until a set time or a set number of dusts are collected.

[0003]

However, the cyclone has a property that the inside is contaminated by the fine particles sucked in structure. Therefore, the response from the place where the concentration of the fine particles is low to the dark direction is quick, but the response from the place where the concentration of the fine particles is low is delayed. As long as it is used as a dust collector, there is no problem. However, when it is used for an application that captures the timing of dust generation, a slow response speed becomes a problem. An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a cyclone dust collecting apparatus which can quickly respond from a place where the concentration of fine particles is high to a place where the concentration is low.

[0004]

In order to achieve the above object, a cyclone dust collecting apparatus according to a first aspect of the present invention comprises a blower 5 for allowing the cyclone 1 to suck the outside air, and a dust collection device for the cyclone. In the cyclone dust collecting apparatus having the pump 4 for sucking the collected fine particles into the dust collecting filter 3, the suction operation of the blower is intermittently operated.

[0005] According to such a configuration, since the suction operation of the blower is intermittently operated, the fine particles adhering to the inner wall of the cyclone fall during the idle period, and the response to the change in the number of fine particles during the suction operation is reduced. Be quick.

Here, if the suction operation of the blower is configured to be completed when a preset time has elapsed, the control is simplified. The suction operation of the blower may be completed when a preset number of fine particles are adsorbed to the dust collecting filter. Here, if the counting of the fine particles is performed by the counter 2 that counts the number of the fine particles contained in the airflow sucked toward the dust collecting filter, the fine particles are adsorbed to the dust collecting filter in real time. The number of fine particles can be measured in advance.

Further, the interruption time in the intermittent operation of the suction operation of the blower may be set to a time sufficient for removing the fine particles attached to the cyclone. If the suspension time is short, due to the inertia of the air flow inside the cyclone, the fine particles adhering to the cyclone enter the next operation cycle as it is, and the purpose of the intermittent operation cannot be achieved.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing one embodiment of the present invention. In the figure, a cyclone 1 is provided with a conical funnel 11 at the lower portion of a cylindrical main body. Do the dust. The counter 2 is provided at the dust outlet 12 of the cyclone 1 and counts the number of fine particles sucked by the dust filter 3. This counter 2
For example, the image of the fine particles may be captured using a CCD or the like using an optical method, and the number of the fine particles may be counted using an image identification device. The dust collection filter 3 captures fine particles contained in air exhausted from the dust outlet 12 by the pump 4, and is made of, for example, a porous polymer film.

The blower 5 generates a swirling flow in the cyclone 1 and is connected to a top exhaust port 13 of the cyclone 1 via a pipe. The controller 6 controls the operation of the blower 5, and performs ON / OFF control here.

Next, the operation of the above-configured apparatus will be described. 2A and 2B are sequence diagrams illustrating the operation of the apparatus in FIG. 1, wherein FIG. 2A illustrates a dust collection operation, and FIG. When the dust collection operation is started, the dust collection operation is continued until the counter 2 counts up a predetermined number of particles or the operation for a set time is completed. On the other hand, the operation of the blower is an intermittent operation, which is temporarily stopped after suction for a certain time (T1), started again, and restarted for a certain time (T2). This fixed time is determined by the capacity of the cyclone 1 and the operating capacity of the prober 5, and is determined so that dust collection can be performed efficiently. Further, the pause time may be set to a time necessary for the fine particles adhered to the inner wall of the cyclone 1 to escape.

FIGS. 3A and 3B are diagrams showing a time-series change in the count value of fine particles. FIG. 3A shows this embodiment, and FIG. 3B shows a conventional example. According to the present embodiment, at the time of 9 minutes, the particle size is 0.3.
The counted value of fine particles having a particle diameter of 0.5 μm or more is 3200, and the counted value of fine particles having a particle diameter of 0.5 μm or more is 500. At the time of 10 minutes, the count value sharply decreases, and the count value of fine particles having a particle size of 0.3 μm or more is 400, and the count value of fine particles having a particle size of 0.5 μm or more is 100. At other times, the particle size is 0.3 μm
The counted value of the fine particles is 200, and the counted value of the fine particles having a particle diameter of 0.5 μm or more is 50 or less.

On the other hand, when the blower 5 continuously sucks the cyclone 1 as in the prior art, the counted value of the fine particles having a particle diameter of 0.3 μm or more is 3700 and the particle diameter is 0.5 in 5 minutes.
The counted value of the fine particles of μm or more indicates 600. Time 6
At the minute, the count value decreases slowly, with the count value of fine particles having a particle size of 0.3 μm or more being 2200 and the count value of fine particles having a particle size of 0.5 μm or more being 400. And time 1-4 minutes,
In addition, after time 11 minutes, the counted value of fine particles having a particle diameter of 0.3 μm or more is 300, and the counted value of fine particles having a particle diameter of 0.5 μm or more is 50.
Shows below and stabilizes.

When the changes in the count values are compared, the count value of the fine particles changes sharply in this embodiment. On the other hand, in the conventional example, the fine particles adhering to the cyclone 1 are affected by the gradual detachment, and once the count value of the fine particles increases rapidly, the decrease is slow, and the time constant is about 4 minutes. Response time is slow. Therefore, according to the present embodiment, it is easy to catch the timing when the number of fine particles rapidly increases, and it is easy to specify the cause of the generation in an application that extremely dislikes the presence of suspended dust, such as a semiconductor factory.

In the above-described embodiment, the stop time in the intermittent operation is provided once, but may be provided a plurality of times.
In short, it is only required that the suspension is such that the fine particles attached to the inner wall of the cyclone 1 escape, and that the swirling flow inside the cyclone 1 is easily generated by the blower.

[0015]

As described above, according to the cyclone dust collecting apparatus of the first aspect, the blower 5 for sucking the outside air into the cyclone 1 and the fine particles collected by the cyclone are collected by the dust collecting filter 3. In the cyclone dust collecting apparatus having the pump 4 for suctioning, the suction operation of the blower is intermittently operated, so that the fine particles attached to the inner wall of the cyclone fall during the idle period, and the number of fine particles during the suction operation varies. To respond quickly.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

FIG. 2 is a sequence diagram illustrating an operation of the device in FIG. 1;

FIG. 3 is a diagram showing a time-series change in a count value of fine particles.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cyclone 2 Counter 3 Dust collection filter 5 Blower 6 Controller

Claims (5)

[Claims] 1. A cyclone dust collector having a blower (5) for sucking an external atmosphere into a cyclone (1) and a pump (4) for sucking fine particles collected in the cyclone to a dust filter (3). The dust collecting apparatus for a cyclone according to claim 1, wherein the suction operation of the blower is performed intermittently. 2. The suction operation of the blower is completed when a preset time has elapsed.
A dust collector for a cyclone as described. 3. The cyclone dust collecting apparatus according to claim 1, wherein the suction operation of the blower is completed when a preset number of fine particles are adsorbed on the dust collecting filter. 4. The cyclone dust collecting apparatus according to claim 3, wherein the counting of the fine particles is performed by a counter (2) for counting the number of the fine particles contained in the airflow sucked into the dust collecting filter. apparatus. 5. The cyclone dust collecting apparatus according to claim 1, wherein the interruption time in the intermittent operation of the suction operation of the blower is a time enough to remove the fine particles attached to the cyclone.