JP3078515B2 - Dust sampler device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust sampler device, and more particularly, to a filter material that can be collected at a constant flow rate without clogging due to clogging, and that the filter material is not wastefully used. The present invention relates to a dust sampler device that can lengthen the replacement interval of the filter, can reduce the size of the filter medium, is easy to maintain, and can save resources and space.

[0002]

2. Description of the Related Art Conventionally, for example, factories and research facilities in industries such as semiconductors, electronic equipment, precision instruments, optics, printing, pharmaceuticals, foods, medical care, microbial engineering, etc. 2. Description of the Related Art A dust sampler device is used for dust removal, collecting radioactive material dust in a nuclear power plant, measuring the concentration of radioactive material in the air, monitoring air pollution such as detecting unexpected air pollution by radioactive materials, and the like.

[0003] The dust sampler device removes dust in the contaminated air by, for example, an air circulation pipe that circulates the air in the contaminated room and a filter paper arranged so as to cross the air circulation pipe. In the case where the filter paper has a dust removing function that can be adsorbed on the filter paper, and the filter paper is fixed so as to cross the air flow pipe, clogging is caused by the dust adsorbed on the filter paper. If this occurs, there is a problem that the air flow pipe is closed and the dust removal and dust collection at a constant flow rate cannot be performed.

Therefore, in order to prevent the filter paper from being clogged, instead of the filter paper, the filter paper extracted from the roll-shaped roll filter paper is replaced with the filter paper. A winding member that is disposed in an air circulation pipe and winds the filter paper extracted from the roll filtration paper; and a delivery member that sends out the filtration paper from the roll filtration paper, the air circulation pipe is provided. A roll-shaped filter paper exchange means for exchanging the filter paper disposed therein for an unused filter paper has been employed.

In the roll-shaped filter paper changing means, the winding member is rotated when a predetermined time elapses before the filter paper is clogged, and the filter paper arranged in the air flow pipe is rotated. To replace the unused filter paper with `` replacement method after a predetermined time '',
Alternatively, the take-up member is always kept at, for example, 2 to 5 cm / h so as not to cause clogging of the filter paper.
The “constant exchange method” is adopted in which the filter paper disposed in the air flow pipe is replaced with unused filter paper by rotating at a low speed at a winding speed of r or a lower winding speed. I was

[0006] In the replacement method when the predetermined time has elapsed,
If the contamination in the air is not always constant, for example, if the amount of dust in the air is small, even if the amount of dust adsorbed on the filter paper is extremely small, the winding member is rotated after a predetermined time has elapsed. Therefore, the filter paper disposed in the air flow pipe is replaced with an unused filter paper.If the amount of dust in the air is large, the filter paper is removed before a predetermined time elapses. There was a risk of clogging due to clogging.

Therefore, in the replacement method after the lapse of the predetermined time, for example, if the filter paper is statistically used for 100 hours and clogging occurs, if the safety factor for preventing clogging is set to 100 times, If the diameter of the air flow pipe is 10 cm, the winding member is
It is necessary to replace the filter paper disposed in the air flow tube with unused filter paper by rotating the filter paper by about 15 cm, so that the filter paper is wasted much and about 90 m / month. After a large-sized roll-shaped filter paper is required and the filter-filter paper arranged in the air flow pipe for a predetermined time is wound by the winding member, the used large-sized roll-shaped filter paper is discarded. Therefore, there is a problem that the amount of waste increases.

Therefore, in the replacement method at the elapse of the predetermined time, for example, a 90 m roll of used large roll filter paper is discarded every month, and a 90 m roll of unused large roll filter paper is discharged every month. It is unavoidable to perform the replacement work to be mounted on the vehicle, and very complicated and heavy maintenance is performed.

[0009] In the constant replacement method as well, in consideration of the safety factor for preventing clogging, the winding member must always be rotated at a very low speed at a winding speed of, for example, 2 to 5 cm / hr. A large amount of paper was wasted, and a large roll-shaped filter paper was required.

In the replacement method after the lapse of the predetermined time and in the continuous replacement method, the prevention of clogging of the filter paper is taken into consideration, for example, by setting a safety factor for preventing clogging, the wasteful filtration is performed. The amount of filter paper used increases, the size of the roll-shaped filter paper increases, a large installation place for the dust sampler device itself is required, and a vicious cycle occurs in which maintenance is labor intensive.

In addition, when the dust sampler device is employed to collect radioactive dust particularly in the nuclear power plant, radioactive dust is collected on a used large-sized roll-shaped filter paper. , Due to its easy handling and special work area, easy maintenance and
It is desired to increase the exchange interval of the roll-shaped filter paper.

It is an object of the present invention to provide a dust sampler device which can collect at a constant flow rate without blocking the filter medium due to clogging and does not waste filter medium.

Another object of the present invention is to provide a dust sampler device which can reduce the size of a filter medium and is easy to maintain.

[0014] Another object of the present invention is to provide a dust sampler apparatus that can lengthen the replacement interval of the filter medium.

Another object of the present invention is to provide a dust sampler device which can save resources and space.

[0016]

A first means for solving the above-mentioned problems is to provide a gas flow passage through which a gas containing particles flows, a filter medium arranged to traverse the gas flow passage, A filter medium replacement unit for replacing the filter medium with the particles attached to an unused filter medium, and a flow rate of a gas flowing in the gas flow path, which is disposed downstream of the position of the filter medium in the gas flow path and is set. A flow cross section variable member for changing a flow cross section of the gas flow passage and a driving member for driving the flow cross section variable member so as to maintain the flow rate, the flow cut section being variable. Control means for controlling the driving of the filter medium replacing means, so as to replace the filter medium with the particles attached to an unused filter medium when the area reaches a predetermined threshold value. Ah A second means for solving the above-mentioned problem is that the filter medium in the first means is a filter paper sent out from a roll-shaped filter paper rolled into a roll. The filter medium changing means includes a take-up member with a drive source for winding the filter paper by a drive source driven by a drive signal output from the control means, and a filter paper delivery member for delivering the filter paper from the roll-shaped filter paper. The drive source-equipped winding member and the filter paper delivery member,
The dust sampler device according to the first means, wherein the filter paper is arranged to be stretched in the gas flow passage, and a third means for solving the above-mentioned problem is the first means.
Wherein the flow cross-sectional area variable member in the means has a valve,
The driving member in the first means is an actuator, and the flow rate holding means in the first means converts the input energy input to the actuator into the driving force of the valve, whereby A flow controller for holding a flow rate at a set flow rate, wherein the control means in the first means, when a detection value obtained by detecting the input energy reaches a predetermined threshold, the flow cross-sectional area is The dust sampler device in the first means, which is a judgment controller for judging that a predetermined threshold value has been reached, is provided in a fourth means for solving the above-mentioned problem, wherein the valve in the third means is an orifice valve. Yes,
The dust sampler device according to the third means, wherein the actuator in the third means is a solenoid, the input energy in the third means is a current, and the flow controller in the third means is a mass flow meter. .

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION

(General Description) A dust sampler device according to the present invention does not use a gas flow passage through which a gas containing particles flows, a filter medium arranged to traverse the gas flow passage, and a filter medium to which the particles adhere. Filter medium exchange means for exchanging the filter medium, and disposed at a position downstream of the filter medium in the gas flow path, so as to maintain the flow rate of gas flowing through the gas flow path at a set flow rate, A flow cross-section variable member that changes the flow cross-sectional area of the gas flow passage, and a flow rate holding unit that includes a driving member that drives the flow cross-sectional area variable member, and when the variable flow cross section reaches a predetermined threshold value And control means for controlling the driving of the filter medium replacing means so that the filter medium having the particles attached thereto is replaced with an unused filter medium.

[0018] The gas flow passage is only required to be able to flow the gas containing the particles from the point at which the gas containing the particles to be sampled is collected to the member having the variable cross-sectional area. ,tube,
Ducts and the like can be mentioned.

The gas flow path may be, for example, a straight pipe, a curved pipe, a U-shaped pipe, a vent, a vent with guide vanes, an elbow, a pipe joint, a valve, a cock, a wire mesh, a perforated plate, a rectifying grid, a tubular rectifying device, A desired flow passage can be formed by combining a perforated plate rectifier and the like.

The cross-sectional shape of the gas flow path when the surface orthogonal to the flow direction of the gas flow path is a cross section is, for example, circular, concentric double circular, non-circular, square,
Examples include a rectangle and a polygon.

The cross-sectional shape and area of the gas flow passage may vary along the gas flow direction in the gas flow passage. For example, a diverging pipe, a narrowing pipe, a diffuser, a shrinking nozzle, or the like is employed. obtain.

[0022] The filter medium is arranged so as to cross the gas flow passage. This filter medium is not particularly limited as long as the particles in the gas containing the particles to be collected can be filtered. For example, various air filters used to remove dust in the air are used. More specifically, for example, using a filter paper, a membrane filter, a filter cloth, a glass filter, a packed layer filter, a screen filter, a sintered porous body such as a ceramic or a metal powder, a spongy metal, or the like. Can be.

[0023] The form of the filter medium is, for example, a roll-shaped material wound into a roll shape, and a drawn portion drawn from the roll-shaped material is oriented in a direction perpendicular to the axial direction of the gas flow passage. The roll-shaped material disposed and having a large area sufficient to block the gas flow passage apparently, and the gas flow passage apparently disposed in a direction perpendicular to the axial direction of the gas flow passage. Non-roll materials such as sheets, films, and mats having an area large enough to block off may be used.

The filter medium may be formed of paper, fiber, a material combining fiber and ceramic, or the like so that predetermined particles in the gas can be filtered.

This filter medium is stretched in the gas flow path so as to block a substantial portion of the gas flow path through which the gas flows and to allow the gas to flow, but to attach particles in the gas to the filter medium. Because of the necessity, a filter material of a form or material that does not have the property of being able to hold its own shape horizontally when holding one end thereof, that is, having no self-shape holding property, as in the case of the non-rolled material, is adopted. At times, it is also possible to adopt a frame on which the filter medium can be stretched, and to stretch the filter medium on this frame. When the filter medium is a roll formed by being rolled into a roll, it must be stretched so that a portion of the filter medium drawn from the roll crosses with a certain tension in the gas flow passage.

The filter medium changing means is formed so that the filter medium arranged in the gas flow passage can be replaced with an unused filter medium.

As the filter medium changing means, for example,
(1) When the filter medium is in the form of a roll, the filter medium is disposed outside the gas flow passage and can be fitted with the filter medium. Roll-shaped object extending means for extending the drawn-out part of the gas flow passage so as to traverse the same with a predetermined tension, and a drive for winding the drawn-out part of the roll-shaped object extended in the gas flow passage (2) a roll-like material exchanging means comprising a winding means with a source;
When the filter medium is a non-roll material, a non-roll material storage means for accumulating the non-roll material, and sending one non-roll material from the non-roll material storage device to the gas flow passage, A non-roll-like object having a non-roll-like object delivery means arranged in the gas flow passage so as to cross the same, and a non-roll-like material take-out means for taking out the non-roll material arranged in the gas flow passage. Exchange means and the like can be mentioned.

The flow rate holding means is disposed downstream of the filter medium in the gas flow path, and holds the flow rate of the gas flowing through the gas flow path at a set flow rate. The apparatus includes a variable flow cross-sectional area member that changes the flow cross-sectional area of the gas flow passage, and a driving member that drives the variable flow cross-sectional area member.

The cross-sectional area of the gas flow passage may be, for example, a cross-sectional area in a plane perpendicular to the flow direction of the gas flow path, an orifice in a plane perpendicular to the flow direction of the orifice arranged in the gas flow path. And the like.

The member for changing the flow cross section is not particularly limited as long as the flow cross section of the gas flow passage can be changed. For example, a valve for changing the flow cross section of the gas flow passage is preferable. Can be used for Examples of the valve include a gate valve, a gate valve, a throttle valve, an orifice valve, a butterfly valve, a Johnson valve, a slide valve,
Examples include a spool valve, a rotary valve, a plate valve, a seat valve, a poppet valve, and the like. The valve may be used alone, or a plurality of the valves may be used in combination. Further, the valve and other pressure control valves, flow control valves,
A plurality of directional control valves, servo valves and the like can be used in combination.

Examples of the driving member include an actuator capable of converting energy into movement of a load. Examples of the actuator include a DC motor, an AC motor, a servo motor, a pulse motor, and a stepping motor. , Electromagnet, solenoid, moving coil, linear motor, ultrasonic motor, laminated P
An electric actuator such as a ZT actuator can be used.

In the flow rate holding means, for example, the valve is driven by the actuator.
The actuator converts the input energy input to the actuator into a driving force for the valve, whereby the flow rate of the gas can be maintained at a set flow rate.

As the input energy, for example, a current can be mentioned, and a current obtained from commercial power can be used.

The flow rate holding means comprising a combination of the variable flow cross section member and the driving member includes, for example, a solenoid valve such as an electromagnetic switching valve or an electromagnetic proportional valve, Regulators may be mentioned.

Specifically, the flow rate of the gas is set by comparing the measured flow rate obtained by measuring the flow rate of the gas flow passage with a predetermined flow rate. A mass flow meter that maintains the flow rate can be given.

[0036] The control means controls the drive of the filter medium changing means so that the filter medium with the particles attached thereto is replaced with an unused filter medium when the variable flow cross-sectional area reaches a predetermined threshold value. Formed.

The control means may determine that the flow cross-section has reached a predetermined threshold when a detection value obtained by detecting input energy input to the actuator reaches a predetermined threshold. And a judgment controller which outputs a drive signal for driving the filter medium replacing means so as to replace the filter medium with the particles attached to an unused filter medium.

More specifically, the determination controller compares the detected value with a predetermined threshold value, determines that the flow cross-sectional area has reached a predetermined threshold value, A comparator which outputs a drive signal for driving the filter medium replacing means so as to replace the filter medium with an unused filter medium can be given.

(Specific Description) An embodiment of the dust sampler according to the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, as an embodiment of the dust sampler device of the present invention, a dust collecting device 1 for radioactive materials in a nuclear power plant can be mentioned.

The dust collecting device 1 includes a gas flow passage 2,
Roll filter paper 3 as an example of a filter medium, roll filter paper exchange means 4 as an example of filter medium exchange means, a mass flow meter 5 as an example of flow rate holding means, and a comparator as an example of control means. 9 is provided.

The gas flow passage 2 has a flow rate of 50 to 200 Nl /
It is a conduit through which gas containing radioactive material dust flows at a flow rate in the range of min.

The roll-shaped filter paper 3 is provided in the gas flow passage 2.
This is a filter medium formed by rolling a filter paper arranged so as to cross over the paper. This filter medium is in the form of a roll.

The roll-shaped filter paper changing means 4 includes a drive motor 4a as a drive source, a take-up shaft 4b with a drive source, a roll-shaped filter paper feed shaft 4c, and a winding shaft side direction changing guide 4d. And a feed shaft side direction change guide 4e.

The roll-shaped filter paper 3 was mounted on the roll-shaped filter paper feed shaft 4c, and the filter paper was pulled out from the roll-shaped filter paper 3, whereby the roll-shaped filter paper 3 was mounted. The roll-shaped filter paper delivery shaft 4c rotates in accordance with the length of the extracted filter paper.

The filter paper drawn out from the roll-shaped filter paper 3 is directed so as to be orthogonal to the gas flow direction in the gas flow passage 2 and to the feed shaft side direction changing guide 4e and the winding shaft side direction changing guide. 4d and is disposed so as to cross the gas flow passage 2.

The leading end (not shown) of the filter paper pulled out from the roll-shaped filter paper 3 is turned by the feed shaft-side turning guide 4e so as to cross the gas flow passage 2. After being traversed through the gas flow passage 2, the direction is changed in the direction of the drive source-equipped winding shaft 4b by the winding shaft-side direction change guide 4d, and is coupled to the drive source-equipped winding shaft 4b.

The roll-shaped filter paper changing means 4 rotates the used drive paper 4c from the roll-shaped filter paper 3 by the drive motor 4a rotating the take-up shaft 4b with the drive source. By winding, the gas flow path 2
Filter paper 3a in the flow passage disposed therein is replaced with unused filter paper 3b.
Can be replaced.

The mass flow meter 5 is disposed in the downstream flow passage 2a downstream of the position of the filter paper 3a in the gas flow passage 2 and is an orifice which is an example of the flow cross section variable member. It comprises a valve 6, a solenoid 7, which is an example of the driving member, and a flow monitoring unit 8.

The orifice valve 6 has an orifice 6a
, A valve plate 6b, and a magnet member 6c.

The solenoid 7 converts a current input to the solenoid 7 into a driving force for driving a magnet member 6c of the orifice valve 6, so that the magnet member 6c drives the valve plate 6b. The orifice 6
The opening area at a is varied, and the flow rate of the gas is maintained at the set flow rate.

The flow monitor 8 comprises a power supply 8a, a digital indicator 8b, a flow setter 8c, a flow path restrictor 8d.
And a flow rate sensor 8e and a flow rate comparison control unit 6f.

In the flow rate monitor 8, first, a preset flow rate is set in the flow rate setting device 8 c in advance.
The gas flow rate in the downstream flow passage 2a can be set to a desired flow rate, and the set flow rate is output to the flow rate comparison control unit 8f as a set flow rate signal.

Next, the flow direction of the gas in the downstream flow path 2a is regulated by the flow path restriction 8d, and the flow rate of the gas in the downstream flow path 2a is measured by the flow rate sensor 8e. Is output to the flow rate comparison control unit 8f as a measured flow rate signal.

The flow rate comparison control section 8f compares the set flow rate signal with the measured flow rate signal and outputs a valve drive signal to the solenoid 7 so that the set flow rate and the measured flow rate become equal. .

When the valve drive signal is output, a current is supplied to the solenoid 7 to drive the magnet member 6c of the orifice valve 6, and the valve plate 6b changes the opening area of the orifice 6a.

In this embodiment, the gas flow passage 2
As the filter paper 3a in (1) collects dust, a part of the filter surface of the filter paper 3a is clogged, and the gas flow through the filter paper 3a decreases.

Therefore, the orifice valve 6 in the dust collecting apparatus 1 of this embodiment is adjusted to be slightly open in the initial state, and as the filter surface of the filter paper 3a is partially clogged, the orifice valve 6 is closed. The orifice valve 6
Driving is performed so that the set flow rate and the measured flow rate become equal, for example, to increase the opening area in the orifice 6a.

The comparator 9 has a voltage setter 9a and a voltage comparison controller 9b.

In the comparator 9, first, a set voltage is set in the voltage setter 9a in advance. In this embodiment, the set voltage corresponds to a predetermined threshold value of a voltage value detected from a current value input to the solenoid 7 in accordance with the current value.

The set voltage is output to the voltage comparison control section 9b as a set voltage signal.

When a current is supplied to the solenoid 7, the voltage comparison control section 9b detects a voltage value corresponding to the current value as a detection voltage from the current value input to the solenoid 7, and detects the detected voltage value. A voltage is compared with a preset set voltage, and when the detected voltage reaches the set voltage, a drive source drive signal is output to the drive motor 4a so as to drive the drive motor 4a.

When the drive motor 4a is driven, the take-up shaft 4b with the drive source takes up the used filter paper 3c, and the filter paper 3a having a part of the filter surface clogged is removed from the gas flow passage 2. The unused filter paper 3
b is disposed in the gas flow passage 2.

The comparator 9 detects a voltage value corresponding to the current value from the current value input to the solenoid 7 as a detection voltage, and when the detected voltage reaches the set voltage which is a predetermined threshold value. It is determined that the flow cross-sectional area has reached a predetermined threshold value, and a drive source drive signal for driving the drive motor 4a is output so that the filter paper 3a to which the particles adhere is replaced with an unused filter paper 3b.

In the upstream flow passage 2b upstream of the position where the filter paper 3a is disposed in the gas flow passage 2, the amount of radiation in the dust of the radioactive substance collected by the filter paper 3a can be measured. A scintillation counter 1a is provided.

The dust collecting device 1 includes the gas flow passage 2
Since the flow rate of the gas flowing through the inside can be maintained at a set constant flow rate, the nuclear radiation power plant is determined based on the radiation amount of the dust measured by the scintillation counter 1a and the time required for collecting the dust. Can monitor the radioactive substance concentration in the predetermined work area.

(Description of Operation) The operation of the dust collecting apparatus 1 will be described below.

A desired set flow rate is set in advance in the flow rate setting device 8c of the mass flow meter 5, and a desired set voltage is set in advance in the voltage setting device 9a of the comparator 9.

The set flow rate is a flow rate set so that gas flows at a desired flow rate in the gas flow passage 2 of the dust collecting device 1.

In the case of this embodiment, the maximum voltage detected by the maximum current that can be supplied to the solenoid 7 of the dust removing device 1 and the resistance of the solenoid 7 in consideration of the safety factor in this embodiment. 90 of voltage
% Voltage.

In the case of this embodiment, the maximum current is a current necessary for bringing the orifice valve 6 into a fully opened state.

The set flow rate is output to the flow rate comparison control section 8f as a set flow rate signal, and the set voltage is output to the voltage comparison control section 9b.

Here, from a predetermined working area in the nuclear power plant, a suitable gas introducing means (not shown) is used.
A gas containing radioactive material dust is introduced into the gas flow passage 2, and a gas containing radioactive material dust flows through the gas flow passage 2.

When a gas containing radioactive material dust flows through the gas flow passage 2, the radioactive material dust is adsorbed on the filter paper 3 a arranged to traverse the gas flow passage 2, The gas from which the radioactive material dust has been removed flows through the downstream flow passage 2 a in the gas flow passage 2.

The gas flowing through the downstream flow passage 2a is:
The flow direction of the gas is regulated by the flow passage restrictor 8d in the mass flow meter 5, and the flow rate of the flowing gas is measured by the flow rate sensor 8e. The measured flow rate is sent to the flow rate comparison control unit 8f as a measured flow rate signal. Is output.

The measured flow rate signal is compared with the set flow rate signal in the flow rate comparison control section 8f, and the flow rate comparison control section 8f controls the solenoid 7 so that the measured flow rate and the set flow rate become equal. Outputs a valve drive signal.

When the valve drive signal is output, a current is supplied to the solenoid 7 to drive the magnet member 6c of the orifice valve 6, and the valve plate 6b increases the opening area of the orifice 6a.

Here, when a current is supplied to the solenoid 7, the voltage comparison control section 9 b in the comparator 9 detects a voltage detected from the current value input to the solenoid 7 in accordance with the current value. The detected voltage is detected as a detection voltage, and the detected voltage is compared with the set voltage. If the detected voltage is smaller than the set voltage, no drive source drive signal is output to the drive motor 4a.

When dust of a radioactive substance is adsorbed on the filter paper 3a and a part of the filter surface of the filter paper 3a is clogged, the flow rate of the gas flowing through the downstream flow passage 2a decreases.

Even when a part of the filter surface of the filter paper 3a is clogged, the flow rate of the gas flowing through the downstream flow passage 2a is measured by the flow rate sensor 8e, and the measured flow rate is a measured flow rate signal. Is output to the flow rate comparison control unit 8f.

The measured flow rate signal is compared with the set flow rate signal in the flow rate comparison control section 8f, and the flow rate comparison control section 8f controls the solenoid 7 so that the measured flow rate and the set flow rate become equal. Outputs a valve drive signal.

When the valve drive signal is output, a current is supplied to the solenoid 7 to drive the magnet member 6c of the orifice valve 6, and the valve plate 6b increases the opening area of the orifice 6a.

Here, when a current is supplied to the solenoid 7, the voltage comparison control section 9 b in the comparator 9 detects a voltage detected from the current value input to the solenoid 7 in accordance with the current value. The detected voltage is detected as a detection voltage, and the detected voltage is compared with the set voltage. When the detected voltage is larger than the set voltage, that is, the detected voltage is detected corresponding to the current value input to the solenoid 7. When the voltage value exceeds the threshold value, a drive source drive signal is output to the drive motor 4a so as to drive the drive motor 4a.

In this embodiment, when the filtering surface of the filter paper 3a is clogged with time and the flow rate of the gas flowing through the downstream flow passage 2a decreases with time,
The mass flow meter 5 increases the opening area of the orifice 6a with time so that the measured flow rate of the gas decreasing with time and the set flow rate are equalized.

In order to increase the area of the opening in the orifice 6a with time, the current flowing through the solenoid 7 must be increased with time.

In this case, the detection voltage detected by the voltage comparison control unit 9b also increases with time due to the resistance of the solenoid 7 and the current that increases with time.

When the detected voltage that increases with time in the solenoid 7 becomes larger than the set voltage, that is, when the detected voltage exceeds a threshold, the voltage comparison control unit 9b drives the drive motor 4a. To output a driving source driving signal.

When the drive motor 4a is driven, the take-up shaft 4b with the drive source winds up the used filter paper 3c, and the filter paper 3a having a part of the filter surface clogged out of the gas flow passage 2. After being pulled out, the unused filter paper 3 b is disposed in the gas flow passage 2.

When the voltage of the solenoid 7 reaches a threshold value, a drive signal is output from the voltage comparison control section 9b to the drive motor 4a. What is particularly important here is that in this embodiment, Since the set voltage is set to 90% of the maximum voltage detected by the maximum current and the resistance in the solenoid 7 in consideration of the safety factor, at this time, the downstream flow passage is set. This means that the flow rate of the gas flowing through 2a holds the set flow rate.

The dust collecting device 1 can always maintain the flow rate of the gas flowing through the downstream flow passage 2a at the set flow rate during dust collection and concentration, and can maintain the gas flow flowing through the downstream flow passage 2a. While the flow rate is maintained at the set flow rate, that is, before the detection voltage reaches the maximum voltage, the filter paper 3 in which a part of the filtration surface has clogged
a can be drawn out of the gas flow passage 2, and the unused filter paper 3 b can be disposed in the gas flow passage 2.

As described above, since the dust collecting device 1 can collect at a constant flow rate, by measuring the amount of radiation collected on the filter paper 3a by the scintillation counter 1a, a predetermined amount in the nuclear power plant can be measured. It is possible to continuously monitor the concentration of radioactive materials in the work area, detect air pollution at an early stage even in special work where air pollution due to radioactivity may occur, More reliably, and the safety of facilities such as nuclear power plants can be improved.

Hereinafter, another embodiment of the dust sampler device of the present invention will be described.

[0093] As shown in FIG.
An air flow passage 11 which is an example of a gas flow passage, a cut filter paper 12 which is an example of a filter medium, a cut filter paper exchange means 13 which is an example of a filter medium exchange means, and a mass flow screen which is an example of a flow holding means. And a comparator 14 which is an example of a control unit. The cut filter paper 12 is a non-rolled material.

The air flow passage 11 is a pipe through which air containing dust flows.

The cut filter paper 12 is provided in the air flow passage 11.
Is arranged to cross.

The cut filter paper replacing means 13 can replace the cut filter paper 12a arranged in the air flow passage 11 with an unused cut filter paper 12b, and stacks the unused cut filter paper 12b. An unused cut-sheet filter paper container 13a capable of receiving and storing the unused cut-sheet filter paper 12b into the air flow passage 11 from the unused cut-sheet filter paper container 13a; A used cut filter paper container 13c capable of stacking and storing used cut filter paper 12c;
A single-cut filter paper collection member 13d with a drive source capable of collecting the used single-cut filter paper 12c from the inside thereof into the used single-cut filter paper container 13c.

The cut-off filter paper delivery member 13 with the driving source
b, an extruding device 15 for extruding the unused cut filter paper 12b contained in the unused cut filter paper container 13a into the air flow passage 11, a driving motor 15a for driving the extruding device 15, It has a transport device 16 for transporting unused cut filter paper 12b into the air flow passage 11, and a drive motor 16a for driving the transport device 16.

The cut filter paper collecting member 13d with the driving source
A discharge device 17 for discharging the used cut filter paper 12c from the air flow passage 11 to the used cut filter container 13c, and a drive motor 17a for driving the discharge device 17
And

As the mass flow meter 5, the one shown in FIG. 2 can be employed. The mass flow meter 5 is provided in the downstream flow passage 11a downstream of the position of the cut filter paper 12a in the air flow passage 11. The orifice valve 6 which is an example of the flow cross-sectional area variable member, the solenoid 7 which is an example of the driving member, and the flow monitoring unit 8 are provided.

The comparator 14 has a voltage setting unit (not shown) and a voltage comparison control unit (not shown).

In the comparator 14, first, a set voltage is set in the voltage setter in advance. In this example,
The set voltage corresponds to a predetermined threshold value in a voltage value detected from the current value input to the solenoid 7 in accordance with the current value.

The set voltage is output to the voltage comparison control section as a set voltage signal.

The voltage comparison control unit is provided with the solenoid 7
When a current is supplied to the solenoid 7, a voltage value corresponding to the current value is detected as a detection voltage from the current value input to the solenoid 7, and the detected voltage is compared with the preset set voltage. When the detection voltage reaches the set voltage, the cut filter paper 12a is removed from the unused cut filter paper 1.
A drive source drive signal for driving the drive motors 15a, 16a and 17a in the cut-sheet filter paper replacing means 13 so as to replace the drive motor 2b with the drive motor 2a is output.

(Explanation of Operation) Hereinafter, the dust collecting apparatus 10 will be described.
Will be described.

First, a plurality of the unused cut filter papers 12b are accommodated in the unused cut filter paper container 13a of the dust collecting apparatus 10, and the drive motor 15a of the cut filter paper delivery member 13b with a driving source is provided. And 16a to drive one unused cut filter paper 12
b is disposed in the air flow passage 11.

Next, a desired set flow rate is set in advance in the flow rate setting device 8c of the mass flow meter 5, and a desired set voltage is set in advance in the voltage setting device of the comparator 14.

The set flow rate is output to the flow rate comparison control section 8f as a set flow rate signal, and the set voltage is output to the voltage comparison control section.

Here, air containing dust is blown by the appropriate air introducing means (not shown).
1 and containing dust-containing air into the air flow passage 1.
1 to distribute.

When air containing dust flows in the air flow passage 11, the dust adsorbs on the cut filter paper 12a arranged to traverse the air flow passage 11,
The air from which dust has been removed and purified is supplied to the air flow passage 11.
In the downstream flow passage 11a.

The air flowing through the downstream flow passage 11a is supplied to the flow passage restrictor 8 in the mass flow meter 5.
d regulates the flow direction, and the flow rate sensor 8e
The flow rate of the flowing air is measured, and the measured flow rate is output to the flow rate comparison control unit 8f as a measured flow rate signal.

The measured flow rate signal is compared with the set flow rate signal in the flow rate comparison control section 8f, and the flow rate comparison control section 8f controls the solenoid 7 so that the measured flow rate and the set flow rate become equal. Outputs a valve drive signal.

When the valve drive signal is output, a current is supplied to the solenoid 7 to drive the magnet member 6c of the orifice valve 6, and the valve plate 6b increases the opening area of the orifice 6a.

Here, the voltage comparison control section of the comparator 14 operates when the solenoid 7 is supplied with a current.
A voltage value detected corresponding to the current value is detected as a detection voltage from a current value input to the solenoid 7, and the detected voltage is compared with the set voltage. Is smaller, the driving motor 1
No drive source drive signal is output to 5a, 16a and 17a.

Dust is adsorbed on the cut filter paper 12a,
When a part of the filtering surface of the cut filter paper 12a is clogged, the flow rate of the air flowing through the downstream flow passage 11a decreases.

Even when a part of the filter surface of the cut filter paper 12a is clogged, the flow sensor 8
The flow rate of the gas flowing through the downstream flow passage 11a is measured by e, and the measured flow rate is output to the flow rate comparison control unit 8f as a measured flow rate signal.

The measured flow rate signal is compared with the set flow rate signal in the flow rate comparison control section 8f, and the flow rate comparison control section 8f controls the solenoid 7 so that the measured flow rate and the set flow rate become equal. Outputs a valve drive signal.

When the valve drive signal is output, a current is supplied to the solenoid 7 to drive the magnet member 6c of the orifice valve 6, and the valve plate 6b increases the opening area of the orifice 6a.

Here, the voltage comparison control unit in the comparator 14 operates when the current is applied to the solenoid 7.
A voltage value detected corresponding to the current value is detected as a detection voltage from a current value input to the solenoid 7, and the detected voltage is compared with the set voltage. Is large, that is, when the voltage of the solenoid 7 reaches a threshold value, a drive source drive signal is output to the drive motors 15a, 16a, and 17a.

The drive motors 15a, 16a and 17
When a is driven, the extruding device 15 pushes out the unused cut filter paper 12b, and the transport device 16 transports the unused cut filter paper 12b into the air flow passage 11.

The cut filter paper 12a having a part of the filtering surface clogged is pushed out of the air flow passage 11 and is discharged by the unloading device 17 into the used cut filter paper container 13c.
To be carried out.

[0121]

According to the dust sampler device of the present invention, (a)
Since the flow rate of the gas flowing in the gas flow path is maintained at a set flow rate, and the filter medium disposed in the gas flow path can be replaced with an unused filter medium, the filter medium is blocked by clogging. (B) The filter medium can be replaced when the filter medium absorbs a predetermined amount of dust, so that the filter medium is not wasted.
(C) Since the efficiency of collecting dust in the filter medium is good and the filter medium can be used without waste, the replacement interval of the filter medium can be lengthened. (D) For example, dust collection of radioactive materials in a nuclear power plant Whereas the conventional apparatus required about 90 m / month of roll-shaped filter paper, the adoption of the dust sampler apparatus of the present invention required only about 20 m / 2 month of roll-shaped filter paper. Therefore, the size of the filter medium can be reduced, and (e)
Since the filter medium can be downsized and the frequency of replacement of the filter medium can be reduced, maintenance is easy,
(F) Since the filter medium is not wasted, resources can be saved, and (g) the apparatus itself can be downsized together with the filter medium, so that space can be saved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing one embodiment of a dust sampler device of the present invention.

FIG. 2 is a schematic diagram of a mass flow meter that can be employed in one embodiment of the dust sampler device of the present invention.

FIG. 3 is a schematic view showing another embodiment of the dust sampler device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Dust collection device, 1a ... Scintillation counter, 2 ... Gas flow path, 2a ... Downstream flow path, 2b ... Upstream flow path, 3 ... Roll shape filter paper,
3a ... filter paper, 3b ... unused filter paper, 3c ...
Used filter paper, 4 ... Roll-shaped filter paper replacement means, 4a ...
.Drive motor, 4b ... winding shaft with drive source, 4c
..Roll-shaped filter paper feed shaft, 4d ... winding shaft side direction changing guide, 4e ... feed shaft side direction changing guide, 5 ... mass flow meter, 6 ... orifice valve, 6a ... orifice, 6b ... valve plate, 6c ...
・ Magnet member, 7 ・ ・ ・ Solenoid, 8 ・ ・ ・ Flow monitor, 8a ・ ・ ・ Power supply, 8b ・ ・ ・ Digital indicator, 8c
... Flow setting device, 8d ... Flow path restriction, 8e ...
Flow rate sensor, 8f: flow rate comparison control unit, 9: comparator, 9a: voltage setting unit, 9b: voltage comparison control unit, 10: dust collecting device, 11: air Channel,
11a: Downstream flow path, 12: Cut filter paper, 12
a: cut filter paper, 12b: unused cut filter paper, 1
2c: used cut filter paper, 13: cut filter paper exchange means, 13a: unused cut filter paper container, 13b: cut filter paper sending member with driving source, 13c: used Cut filter paper container, 13d: Cut filter paper collecting member with drive source, 14: Mass flow meter, 15: Extruder, 15a: Drive motor, 16: Transport device, 1
6a: drive motor, 17: unloading device, 17a
..Drive motors.

Claims (4)

(57) [Claims] 1. A gas flow path through which a gas containing particles flows, a filter medium arranged to traverse the gas flow path, and a filter medium exchange means for exchanging the filter medium with the particles attached to an unused filter medium. And a flow cross-sectional area of the gas flow path, which is disposed downstream of the position of the filter medium in the gas flow path and maintains a flow rate of gas flowing through the gas flow path at a set flow rate. And a flow rate holding means including a driving member that drives the flow cross-sectional area variable member and the flow cross-sectional area variable member, and a filter medium to which the particles adhere when the variable flow cross-sectional area reaches a predetermined threshold. Control means for controlling the driving of the filter medium replacing means so that the filter medium is replaced with an unused filter medium. 2. The filter medium according to claim 1, wherein the filter medium is a filter paper fed from a roll-shaped rolled paper.
The filter medium replacing means according to claim 1, wherein the filter medium is wound by a drive source driven by a drive signal output from the control means, and a filter paper for feeding the filter paper from the roll-shaped filter paper. And a delivery member,
2. The dust sampler device according to claim 1, wherein the winding member with a driving source and the filter paper sending member are arranged so as to stretch the filter paper into the gas flow passage. 3. 3. The variable flow cross-sectional area member according to claim 1 includes a valve, the driving member according to claim 1 is an actuator, and the flow rate holding unit according to claim 1 is configured such that the actuator is the actuator. Is a flow controller that converts the input energy input to the valve into a driving force of the valve to maintain the flow rate of the gas at a set flow rate. The control unit according to claim 1,
The dust sampler device according to claim 1, further comprising a determination controller configured to determine that the flow cross-section has reached a predetermined threshold when a detection value obtained by detecting the input energy has reached a predetermined threshold. 4. The valve according to claim 3, wherein the valve is an orifice valve, the actuator according to claim 3 is a solenoid, the input energy according to claim 3 is current, and the flow controller according to claim 3 is a mass flow controller. The dust sampler device according to claim 3, which is a meter.