JP2942882B2 - Dust collector - 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 collector, and more particularly to a dust collector suitable for use in a cyclone dust collector.

[0002]

2. Description of the Related Art Generally, a dust collector is widely used as a device for preventing air pollution in a work environment such as a factory or a process device used in a process. Above all, the cyclone type dust collector using centrifugal force can process a large amount of gas, and the maintenance cost and operation cost can be reduced compared to the filter type and other types of dust collectors, so that it can be used in many fields. Used in

Conventionally, as shown in FIG. 8, in a cyclone type dust collecting apparatus 1, a gas 2 to be collected is drawn from an inlet 4 to a cylindrical portion 5A of a cyclone 5 by a suction force of an exhaust pump 3. Introduce. The gas 2 descends toward the conical portion 5B of the cyclone 5 while drawing a spiral trajectory in the cylindrical portion 5A. At this time, the trajectory of the particles to be collected contained in the gas 2 becomes larger due to the centrifugal force than the trajectory drawn by the gas flow. As a result, particles having a relatively large mass collide with and adhere to the inner wall surface of the cylindrical portion 5A.

Furthermore, when the gas flow descends while drawing a spiral trajectory and enters the conical portion 5B, the radius of rotation of the gas flow gradually decreases, and the acceleration applied to the particles gradually increases according to the law of conservation of angular momentum. The trajectory of the particles is larger than the trajectory of the gas flow. In other words,
The particles are shifted out of the rotating arc of the airflow based on their mass. As a result, particles having a relatively small mass that do not adhere to the inner wall of the cylindrical portion 5A collide with and adhere to the inner wall surface of the conical portion 5B.

The particles adhering to the inner wall surfaces of the cylindrical portion 5A and the conical portion 5B agglomerate with the particles adhering later and increase in mass, so that the particles fall down along the inner wall surface due to gravity, and eventually trap 6. To fall. The clean gas 7 from which the particles have been removed passes through the exhaust pipe 8 and is discharged out of the cyclone 5.

[0006]

As described above, in the cyclone type dust collector 1, when the gas 2 is rotated in the cyclone 5, the particles are removed based on the centrifugal force generated in the particles contained in the gas 2. As a result, it is difficult for the cyclone type dust collector 1 to remove minute particles having a very small mass.

Therefore, conventionally, a cyclone type dust collector has been proposed in which the centrifugal force applied to the particles is increased by reducing the size of the cyclone, and the particle size of the particles that can be removed by this is further reduced. ing. In addition, a so-called scrubber-type cyclone-type dust collector has been proposed, in which fine water droplets are sprayed into a cyclone and particles are trapped in the water droplets so that the particle size of the trappable particles can be further reduced.

However, even when the cyclone is miniaturized or the scrubber system is applied as described above, the minimum particle size of the trappable particles is limited to about 0.2 [μm]. There is a problem that the minimum diameter of the trappable particles is large as compared with the apparatus. As a result, in the conventional cyclone type dust collector, fine particles having a particle size of 0.1 [μm] or less, toxic gas, and the like cannot be removed.

The present invention has been made in view of the above points, and it is an object of the present invention to propose a dust collector capable of removing much smaller particles.

[0010]

According to a first aspect of the present invention, a gas 13A to be collected is introduced into a cyclone 17, and a centrifugal force generated in particles in the gas 13A in the cyclone 17 is reduced. In a dust collector that removes particles from a gas by using the same, a particle concentration detecting unit 32 that detects the particle concentration of the gas 13A, and a gas 13A detected by the particle concentration detecting unit 32 with respect to the gas 13A.
Means 14 for adding steam 14C in an amount corresponding to the particle concentration of the gas, and gas 13A to which steam 14C has been added.
Means 16 for cooling the gas, and introduction means 1 for introducing the gas 13A cooled by the cooling means 16 into the cyclone 17.
2, 15 are provided. Further, in the second invention, in the dust collecting apparatus for introducing the gas 13A to be collected into the cyclone 17 and removing particles from the gas by using centrifugal force generated in the gas 13A in the cyclone 17, Steam addition means 14 for adding steam 14C to gas 13A, and gas 1 to which steam 14C has been added;
Cooling means 46 for cooling 3A and introducing means 12 for introducing gas 13A cooled by cooling means 46 into cyclone 17 are provided. Cooling means 46 performs a cooling action by adiabatic expansion of gas 13A discharged from cyclone 17. Is used to cool the gas 13A.

[0011]

In the first aspect, the gas 13A cooled by the cooling means 16 becomes saturated, and the gas 13A is cooled.
Water vapor 14C condenses around the particles contained in A.
As a result, even particles having a very small mass having a particle size of 0.1 [μm] or less become particles having a large apparent mass, and can be removed by the cyclone 17. In this case, in the first invention, since an amount of water vapor 14C according to the particle concentration of the gas 13A is added,
Regardless of the level of the particle concentration, a proper amount of water vapor 14C can be condensed on the particles to be collected, and the particles can be collected more efficiently. Also in the second invention,
The gas 13A cooled by the cooling means 46 becomes saturated, and the water vapor 14C condenses around the particles contained in the gas 13A. As a result, even particles having a very small mass having a particle size of 0.1 [μm] or less become particles having a large apparent mass, and can be removed by the cyclone 17. In this case, in the second invention, the gas 13A is cooled by utilizing the cooling action of the gas 13A discharged from the cyclone 17 by adiabatic expansion, so that the gas 13A is efficiently used without using liquid nitrogen or the like. The gas 13A can be cooled.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

(1) First Embodiment In FIG. 1, reference numeral 10 denotes a cyclone-type dust collector as a whole. An exhaust pipe (not shown) of a factory facility is connected to an introduction pipe 11 and an exhaust pump 12 The air 13A to be collected by the suction port 11A is collected by the introduction pipe 11, the water vapor generation unit 14, and the introduction pipe 15.
After passing through the cyclone 17, particles in the air 13 A are removed in the cyclone 17 whose surface is cooled by the cooling unit 16, and only the clean air 13 B passes through the exhaust pipe 18 and is outside the cyclone dust collector 10. It is made to be exhausted.

That is, in the cyclone type dust collecting apparatus 10, the steam generating section 14 is provided at a position communicating with the introduction pipes 11 and 15. The steam generating section 14 is constituted by a water tank 14A and a heating section 14B provided adjacent to the bottom of the water tank 14A, whereby the water stored in the water tank 14A is transferred to the heating section 14B. Thus, by heating, steam 14C is generated and this steam 14C is supplied to the introduced air 13A.

The introduction pipe 15 is attached to the cylindrical portion 17A such that the longitudinal direction of the pipe coincides with the tangential direction of the circle of the cross section of the cylindrical portion 17A of the cyclone 17, whereby the introduction pipe 15 is introduced into the cyclone 17. The introduced air 13A is configured to spirally rotate inside the cyclone 17.

The cooling section 16 comprises a cooling pipe 16A spirally wound around the outer surface of the cyclone 17, and a liquid nitrogen cylinder (not shown) for supplying liquid nitrogen to the cooling pipe 16A, thereby providing a cyclone type collecting pipe. Dust device 10
In the above, air flowing through the cyclone 17 is cooled by flowing liquid nitrogen through the cooling pipe 16A.

In the above configuration, the introduced air 13A taken in from the inlet 11A flows into the cyclone 17 after the steam 14C is supplied when passing through the steam generating section 14. The introduced air 13A draws a spiral trajectory in the cylindrical portion 17A of the cyclone 17 while forming a conical portion 17A.
It descends toward B. At this time, the introduced air 13A becomes supersaturated because the cyclone 17 is cooled by the cooling unit 16.

As a result, the water vapor 14 in the introduced air 13A is
C condenses on particles contained in the air. That is, water is surrounded around the particles. Particles in which water vapor 14C has condensed have an apparent mass that is larger than that of the particles alone. As a result, the centrifugal force in the cyclone 17 becomes larger than that of the particle alone, and the particle adheres to the inner wall of the cyclone 17. Thereby, the cyclone type dust collector 10
In this case, the conventional cyclone type dust collector can also remove fine particles which cannot be removed due to its small mass.

Further, in the cyclone type dust collecting apparatus 10, even when the introduced air 13A contains a toxic gas such as a hydrochloric acid gas or a hydrofluoric acid gas, the toxic gas is condensed into water droplets (condensed on particles) or dew condensation. The toxic gas contained in the introduced air 13A can be removed by being taken into the inner wall of the cyclone.

As shown in FIG. 2, the temperature is 30 [°
The vapor pressure of water in the gas [C] is 31.824 [mmHg], whereas the vapor pressure of water at a temperature of 0 [° C] is 4.579 [mmHg]. Accordingly, after supplying steam to a gas having a temperature of 30 ° C. to obtain a gas having a humidity of 80%,
When this gas is cooled to 0 [° C], the degree of supersaturation of the gas becomes

(Equation 1) Can be calculated as 560%.

At 0 ° C., the degree of supersaturation is 560
The critical diameter d of the particles in the gas of [%] is p, the vapor pressure of the droplet is p, the saturated vapor pressure on the plane is p ₀ , the surface tension of water is γ, the molecular weight of water is M, the gas constant is R, If the absolute temperature is T and the density of water is ρ, the Thomson-Gibbs equation,

(Equation 2) 6.7 × 10 ⁻⁴ [μm] (6.7 [Å]). This shows that the cyclone type dust collector 10 can theoretically remove much smaller particles than conventional ones.

According to the above configuration, the steam generator 14 supplies the steam 14C to the air 13A to be collected.
And a cooling unit 16 for cooling the cyclone 17
The cyclone dust collecting apparatus 10 which can collect even particles having a small particle size, that is, particles having a small mass that cannot be collected by the cyclone 17 by itself can be realized. In addition, since the toxic gas can be absorbed by the water droplets of water vapor (condensed on particles) and the inner wall of the cyclone that has condensed, the toxic gas that cannot be collected by the conventional cyclone type dust collector can also be removed.

(2) Second Embodiment FIG. 3, in which parts corresponding to those in FIG. 1 are assigned the same reference numerals, shows a second embodiment, and the cyclone type dust collector 20 is the cyclone type of the first embodiment. Compared to the dust collector 10, the cooling unit 26
Position is different. That is, in the cyclone type dust collector 20, the cooling unit 26 is provided between the steam generator 14 and the cyclone 17, whereby the cyclone type dust collector 20 is supplied with the steam 14C by the steam generator 14. After cooling the introduced air 13A by the cooling section 26, the introduced air 13A is introduced into the cyclone 17.

The cooling unit 26 includes a cylindrical cooling cylinder 26B,
The cooling pipe 26A includes a cooling pipe 26A spirally wound around the outer surface of the cooling cylinder 26B, and a liquid nitrogen pump (not shown) for supplying liquid nitrogen to the cooling pipe 26A. Thereby, the cooling unit 26 can cool the introduced air 13A passing through the cooling cylinder 26B by flowing the liquid nitrogen into the cooling pipe 26A.

In the above-described configuration, when the introduced air 13A to be collected from the inlet 11A passes through the steam generator 14, steam 14C is supplied. The introduced air 13A flows into the cooling unit 26. At this time, the introduced air 13A is supersaturated by being cooled by the cooling unit 26, and as a result, the water vapor 14C in the introduced air 13A condenses on particles contained in the introduced air 13A.
The particles in which the water vapor 14C has condensed flow into the cyclone 17 in a state where the apparent mass is larger than that of the particles alone.
As a result, the centrifugal force of the particles in the cyclone 17 becomes larger than that of the particle alone, and the cyclone 17
Adheres to the inner wall of Thereby, cyclone type dust collector 2
In the case of 0, fine particles which could not be removed conventionally because of their small mass can also be removed.

According to the above configuration, the steam generator 14 supplies the steam 14C to the air 13A to be collected.
And the introduced air 1 supplied with the steam 14C.
By providing the cooling unit 26 for cooling the 3A, the apparent mass of the fine particles introduced into the cyclone 17 can be increased, and thus the particle size is so small that the particles alone cannot be collected by the cyclone 17. That is, it is possible to realize the cyclone type dust collecting device 20 that can collect even particles having a small mass. In addition, since toxic gas can be absorbed by water droplets (condensed on particles) and dew condensation on the inner wall of the cyclone, toxic gas which cannot be collected by the conventional cyclone type dust collector can be removed.

Further, the cyclone type dust collector 20 can be configured by providing the steam generating part 14 and the cooling part 26 independently of the cyclone on the upstream side of the cyclone in a normal cyclone type dust collector, so that the existing cyclone type dust collector is provided. It is preferable because it can be easily realized by adding a modification in which the steam generation unit 14 and the cooling unit 26 are added to the dust collector.

(3) Third Embodiment FIG. 4 in which parts corresponding to those in FIG. 1 are assigned the same reference numerals as in FIG. 4 shows a third embodiment, and the cyclone type dust collector 30 has a steam control unit 31. The steam controller 31 is a particle concentration measuring device 32
And one end of a sampling pipe 33 branched from the introduction pipe 11 is connected to the particle concentration measuring device 32. Thereby, the steam control section 31 introduces a part of the introduced air 13A into the particle concentration measuring device 32.

The water vapor control section 31 measures the particle concentration of the introduced air 13A by the particle concentration measuring device 32 and sends out a measurement result signal S1 corresponding to the measurement result to the controller 34. The controller 34 sends a control signal S2 corresponding to the measurement result signal S1 to the heating unit 14B of the steam generation unit 14, and as a result, the heating unit 14B applies a voltage based on the control signal S2 to the heater.

Thus, in the cyclone type dust collecting apparatus 30, steam 14C corresponding to the particle concentration of the particles contained in the introduced air 13A can be generated. In other words, the cyclone type dust collector 30 increases the amount of water vapor 14C generated when the particle concentration is high, and decreases the amount of water vapor 14C generated when the particle concentration is low. .

According to the above configuration, the steam control section 31 is provided, and the supply amount of steam 14C to be supplied to the introduced air 13A in the steam generating section 14 is adjusted in accordance with the particle concentration of the particles contained in the introduced air 13A. Thereby, regardless of the level of the particle concentration of the introduced air 13A, an appropriate amount of water vapor 14C can be condensed on the particles to be collected, and the particles can be collected more efficiently.

(4) Other Embodiments (4-1) In the above-described embodiment, the cooling unit 16 or 26 cools the introduced air 13A supplied with the steam 14C using liquid nitrogen. However, the present invention is not limited to this, and various cooling means can be applied. For example, as shown in FIG. 5, a cooling effect by adiabatic expansion of air may be used. That is, in the cooling unit 46, two types of thin-walled pipes 46A and 46B having a large diameter and a small diameter are coaxially arranged. Large diameter pipe 46A
The both end faces formed by the small-diameter pipe 46B are closed except for the inner diameter portion of the small-diameter pipe 46B, and the large-diameter pipe 4B is closed.
A plurality of pores 46C are provided on the outer surface of 6A.

As a result, the cyclone type dust collector 40 is
The air 13B exhausted from the cyclone 17 is guided by an exhaust pipe 41 into a space formed by the large-diameter pipe 46A and the small-diameter pipe 46B of the cooling unit 46, and the air 13B
The pores 46C provided on the outer surface of the large diameter pipe 46A
Large diameter pipe 46A and small diameter pipe 46
By cooling the air in the space formed by B, the introduced air 13A passing through the inside of the small-diameter pipe 46B is cooled.

(4-2) The cyclone type dust collecting apparatus 10, 20, or 30 in the above embodiment takes in air 13A exhausted from the exhaust duct of the factory equipment and discharges purified air 13B to the atmosphere. However, the present invention is not limited to this, and the cyclone type dust collector 1
0, 20 or 30 may be arranged in the air circulation system of the clean room. For example, as shown in FIG. 6, when the cyclone type dust collecting apparatus 20 of the second embodiment is arranged in the air circulation system of a clean room,
The first exhaust 52 is taken into the cyclone type dust collecting device 20 via the gray tag 53, the blower 54 and the exhaust duct 55, and the purified air 56 is discharged again into the clean room 51 via the air duct 57 and the gray tag 58. What should I do?

As described above, the cyclone type dust collector 10, 20 or 3 according to the present invention is installed in the air circulation system of the clean room.
If 0 is used, a maintenance-free clean room that can be operated continuously for a long period of time can be realized while removing fine particles in the air. That is, the filter-type dust collector widely used in the conventional clean room has an advantage that fine particles in the clean room can be removed, but the filter needs to be replaced periodically. As a result, there was a disadvantage that the operation of the clean room had to be stopped when the filter was replaced.

(4-3) Cyclone type dust collector 1
0, 20, or 30 may be applied to the clean bench. That is, as shown in FIG. 7, the cyclone type dust collecting device 20 takes in the introduced air 61 containing dust and the like into the cyclone type dust collecting device 20 via the gray tag 62, the blower 63 and the exhaust duct 64 and is cleaned. Air 65
Is discharged into a space above the work table 68 through the air supply duct 66 and the gray tag 67.

(4-4) Further, in the above embodiment, the case where the water stored in the water tank 14A is heated by the heating unit 14B to generate the steam 14C has been described. However, the present invention is not limited to this, and steam may be generated using ultrasonic waves.

[0038]

As described above, according to the present invention, the dust to be collected is introduced into the cyclone, and the particles are removed from the gas using the centrifugal force generated in the gas in the cyclone. In the apparatus, a particle concentration detecting means for detecting a particle concentration of the gas, a steam adding means for adding an amount of water vapor to the gas in accordance with the particle concentration of the gas detected by the particle concentration detecting means, and the water vapor is added. By providing a cooling means for cooling the cooled gas and an introduction means for introducing the gas cooled by the cooling means into the cyclone, a dust collection device capable of removing even smaller particles more efficiently is realized. it can. Further, according to the present invention, in a dust collection device that introduces a gas to be collected into a cyclone and removes particles from the gas using centrifugal force generated in the gas in the cyclone, water vapor is added to the gas. A cooling means for cooling the gas to which the steam is added, and an introduction means for introducing the gas cooled by the cooling means into the cyclone, wherein the cooling means performs adiabatic expansion of the gas discharged from the cyclone. Since the gas is cooled by utilizing the cooling effect of the present invention, it is possible to realize a dust collector capable of removing still smaller particles while efficiently cooling the gas.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing the overall configuration of a first embodiment of a cyclone type dust collector according to the present invention.

FIG. 2 is a chart for explaining the operation of the first embodiment;

FIG. 3 is a schematic sectional view showing the overall configuration of a second embodiment of the cyclone type dust collector according to the present invention.

FIG. 4 is a schematic sectional view showing the overall configuration of a third embodiment of the cyclone type dust collecting apparatus according to the present invention.

FIG. 5 is a schematic sectional view showing another embodiment of the cyclone type dust collecting apparatus according to the present invention.

FIG. 6 is a schematic diagram showing another embodiment of a cyclone type dust collecting apparatus according to the present invention.

FIG. 7 is a schematic diagram showing another embodiment of a cyclone type dust collector according to the present invention.

FIG. 8 is a schematic side sectional view showing a conventional cyclone type dust collector.

[Explanation of symbols]

1, 10, 20, 30 ... cyclone type dust collector, 2,
13A, 52, 61 ... introduction air, 5, 17 ... cyclone, 7, 13B, 56, 65 ... clean air, 14 ...
Steam generating section, 16, 26, 46 cooling section, 16A
... cooling pipe.

Claims (2)

(57) [Claims] 1. A dust collecting apparatus for introducing a gas to be collected into a cyclone and removing the particles from the gas by utilizing a centrifugal force generated in the cyclone by the particles in the gas. and particle concentration detecting means for detecting the concentration, for the above gas, is detected by the particle concentration detection means
Amount of the water vapor according to the particle concentration of the
And steam adding means for adding, a cooling means for cooling the gas which the water vapor is added, the cyclo the gas cooled by the cooling means
A dust collecting device, comprising: an introducing means for introducing the dust into the dust collecting device. 2. A gas to be collected is introduced into a cyclone.
Centrifugation of particles in the gas in the cyclone
Dust collector that removes the particles from the gas using force
, A steam adding means for adding steam to the gas, and a cooling means for cooling the gas to which the steam is added
And the gas cooled by the cooling means is transferred to the cyclone.
Introducing means for introducing gas into the gas , wherein the cooling means is provided by adiabatic expansion of the gas discharged from the cyclone.
Cooling by utilizing the action and characterized by cooling the gas that
Dust collector.