JP3555007B2 - Dust collector for cyclone - Google Patents

Description

[0001]
TECHNICAL 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]
[Prior art]
The present applicant has proposed a cyclone dust collector in Japanese Patent No. 2754941 or the like. Such a dust collector, for example, analyzes airborne dust in a clean room, identifies the source of the dust, improves the yield of semiconductors, or counts particles in the smoke 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]
[Problems to be solved by the invention]
However, the cyclone has a property that the inside is contaminated by the sucked fine particles due to its 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 the purpose of catching the timing of dust generation, a slow response speed becomes a problem. An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide a cyclone dust collecting device that can quickly respond from a position where the concentration of fine particles is high to a position where the concentration is low.
[0004]
[Means for Solving the Problems]
In order to achieve such an object, the present invention provides:
In a cyclone dust collector having a blower that causes the cyclone to suck the external atmosphere, and a pump that is continuously operated during the dust collection operation and a pump that suctions the fine particles collected in the cyclone to a dust collection filter,
A counter is provided between the lower part of the cyclone and the dust collection filter to count the number of fine particles contained in the airflow sucked toward the dust collection filter, and the blower is operated intermittently during the dust collection operation. The suction operation is interrupted, and the interruption time in the intermittent operation of the suction operation of the blower is a time sufficient for removing the fine particles attached to the cyclone.
[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 becomes quick. .
[0006]
Here, if the suction operation of the blower is configured to be completed when a preset time has elapsed, the control is simplified. Further, the suction operation of the blower may be completed when a predetermined number of fine particles are adsorbed on 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 to the dust collecting filter side, the fine particles are adsorbed to the dust collecting filter in real time. The number of fine particles can be measured in advance.
[0007]
Further, as in claim 5, as the interruption time in the intermittent operation of the suction operation of the blower, a time sufficient for removing the fine particles attached to the cyclone may be selected. 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 they are, and the purpose of the intermittent operation cannot be achieved.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described 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 a 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. The counter 2 may use, for example, an optical system to capture an image of fine particles using a CCD or the like, and count the number of fine particles using an image identification device. The dust collection filter 3 captures fine particles contained in the air exhausted by the pump 4 from the dust outlet 12 and, for example, a porous polymer film is used.
[0009]
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.
[0010]
The operation of the device configured as described above will now 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 required for the fine particles adhered to the inner wall of the cyclone 1 to escape.
[0011]
3A and 3B are diagrams showing a time-series change in the count value of fine particles, wherein FIG. 3A shows the present embodiment, and FIG. 3B shows a conventional example. According to the present embodiment, at the time of 9 minutes, the count value of the fine particles having a particle size of 0.3 μm or more is 3200, and the count value of the fine particles having a particle size 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 count value of fine particles having a particle size of 0.3 μm or more is 200, and the count value of fine particles having a particle size of 0.5 μm or more is 50 or less.
[0012]
On the other hand, when the blower 5 continuously sucks the cyclone 1 as in the conventional case, at a time of 5 minutes, the counted value of the fine particles having a particle diameter of 0.3 μm or more is 3700, and the particle diameter of 0.5 μm or more is obtained. The counted value of the fine particles is 600. At the time of 6 minutes, the count value decreases slowly. The count value of the fine particles having a particle size of 0.3 μm or more is 2200, and the count value of the fine particles having a particle size of 0.5 μm or more is 400. After the time of 1 to 4 minutes and the time of 11 minutes or more, the count value of the fine particles having a particle size of 0.3 μm or more is 300, and the count value of the fine particles having a particle size of 0.5 μm or more is 50 or less, which is stable.
[0013]
Comparing the changes in the count values, 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 counted value of the fine particles rises rapidly, the decrease becomes 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 in an application where the existence of suspended dust is extremely dislike as in a semiconductor factory, it is easy to specify the cause of the generation.
[0014]
In the above-described embodiment, the suspension time in the intermittent operation is provided once, but may be provided a plurality of times. In short, the suspension time is such that the fine particles attached to the inner wall of the cyclone 1 escape. What is necessary is that the swirl flow inside the cyclone 1 is easily generated by the blower.
[0015]
【The invention's effect】
As described above, according to the cyclone dust collecting apparatus of the present invention, the cyclone dust collecting apparatus includes the blower that causes the cyclone to suck the outside air and the pump that suctions the fine particles collected by the cyclone to the dust collecting filter. In the apparatus, since the suction operation of the blower is intermittently operated during the dust collection operation, the fine particles adhering to the inner wall of the cyclone fall during the idle period, and the fine particles are sucked into the dust collection filter by the continuously operating pump. Is done . Responsiveness to a change in the number of fine particles during the suction operation is increased.
[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 of FIG. 1;
FIG. 3 is a diagram showing a time-series change in a count value of fine particles.
[Explanation of symbols]
1 Cyclone 2 Counter 3 Dust collection filter 5 Blower 6 Controller

Claims (3)

In a cyclone dust collector having a blower that causes the cyclone to suck the external atmosphere, and a pump that is continuously operated during the dust collection operation and a pump that suctions the fine particles collected in the cyclone to a dust collection filter,
A counter is provided between the lower part of the cyclone and the dust collection filter to count the number of fine particles contained in the airflow sucked toward the dust collection filter, and the blower is operated intermittently during the dust collection operation. A dust collection device for a cyclone, wherein a suction operation is interrupted, and an interruption time in the intermittent operation of the suction operation of the blower is a time sufficient for removing fine particles adhering to the cyclone. 2. The cyclone dust collecting apparatus according to claim 1, wherein the dust collecting operation is completed when a preset time has elapsed. 2. The cyclone dust collecting apparatus according to claim 1, wherein the dust collecting operation is completed when a predetermined number of fine particles are adsorbed to the dust collecting filter.

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