JP4076215B2 - Static eliminator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a static eliminator, and relates to an apparatus capable of ejecting ions over a wide range while stably generating ions.
[0002]
[Prior art]
Conventionally, as this type of static eliminator, there is one disclosed in Patent Document 1, for example. This is an annular grounding that is externally fitted to one opening (ion discharge port) of the air guide tube by applying a voltage to the discharge needle arranged in the cylindrical air guide tube (ion generating chamber). Corona discharge is generated between the electrodes, and ions generated thereby are sent from the other opening of the air guide tube, so that the ions are ejected to the outside together with the air flow.
[0003]
By the way, depending on the usage mode of the static eliminator, there is a desire to eject ions over a wide range. On the other hand, if the flow rate of the air flow flowing into the air guide pipe from the air inlet per unit time is increased, the momentum of the air flow injected from the air outlet increases (the flow velocity becomes faster). ) Ions are released farther away. Since the air flow diffuses as it flows, ions can be released over a wide range as the air flow is released far away.
However, when an air flow excessively flows into the air guide tube, the air pressure in the air guide tube increases, and as a result, a discharge start voltage (hereinafter referred to as a discharge start voltage) which is a voltage necessary for generating corona discharge. ) Increases, the corona discharge becomes unstable, and the amount of ion generation decreases.
[0004]
[Patent Document 1]
Japanese Patent No. 2954921 [0005]
[Problems to be solved by the invention]
As another means, there is a method of discharging ions in a wide range by injecting a large amount of air flow by enlarging the diameter of the air guide tube. In this case, the diameter of the ground electrode must be increased, and the distance between the discharge needle and the ground electrode is increased. Therefore, the discharge start voltage is increased, the corona discharge becomes unstable, and the amount of generated ions decreases. There is.
Of course, a method of increasing the applied voltage between the discharge electrode and the ground electrode in accordance with the amount of air supplied from the air inlet is also conceivable, but the amount of harmful ozone generated along with the generation of ions by corona discharge is Since it increases rapidly as the discharge start voltage increases, it is not an appropriate method.
[0006]
The present invention has been completed based on the above-described circumstances, and an object thereof is to provide a static eliminator capable of emitting ions in a wide range while stably generating ions.
[0007]
[Means, actions and effects for solving the problems]
As a means for achieving the above object, the invention of claim 1 is characterized in that a discharge needle is arranged coaxially with a gap from the ground electrode in a cylindrical ion generation chamber surrounded by the ground electrode. The corona discharge is generated by applying a voltage between the ground electrode and the discharge needle and air is supplied from one end side of the ion generation chamber to release ions existing on the other end side of the ion generation chamber. In the apparatus in which air containing ions is allowed to flow out from the outlet, an auxiliary air discharge port is provided in the vicinity of the ion discharge port, and the discharge direction side of the air flow discharged from the ion discharge port from the auxiliary air discharge port It is characterized in that air is discharged toward the surface.
[0008]
According to the first aspect of the present invention, the air flow containing ions from the ion discharge port is drawn into the air flow discharged from the auxiliary air discharge port, and is discharged far away by multiplying the air flow. Thus, ions can be released in a wide range. Therefore, it is possible to prevent the corona discharge from becoming unstable due to increasing the flow rate per unit time of the air flow flowing into the ion generation chamber or adopting a method of increasing the size of the ion generation chamber. Ions can be ejected over a wide range while avoiding the adverse effect of a reduced ion production amount.
[0009]
The invention of claim 2 is characterized in that, in the invention of claim 1, the flow velocity of the air flow discharged from the auxiliary air discharge port is made faster than the flow velocity of the air flow discharged from the ion discharge port. As a result, the air flow blown from the ion discharge port is drawn into the air flow from the auxiliary air discharge port, and it is possible to more effectively prevent the air flow from stagnating in the ion generation chamber.
According to a third aspect of the present invention, in the first or second aspect of the present invention, the air supply path connected to the auxiliary air discharge port and the air supply path connected to the ion generation chamber are connected to the same air supply means. The channel cross-sectional area of the auxiliary air discharge port is smaller than that of the ion discharge port.
In this way, the air flow for the ion generation chamber and the air flow for the auxiliary air discharge port can be rationally generated by a single air supply means.
Furthermore, the invention of claim 4 is characterized in that, in the invention of any one of claims 1 to 3, a plurality of auxiliary air discharge ports are provided so as to surround the periphery of the ion discharge port, whereby Can be sprayed evenly.
According to a fifth aspect of the present invention, in any one of the first to third aspects of the present invention, the auxiliary air discharge port and the air supply means connected thereto are formed in an annular shape so as to surround the ion emission port. In this configuration, ions can be ejected more reliably.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a static eliminator according to the present invention will be described with reference to FIGS. 1 to 5. In FIG. 1, the direction of arrow A is the front.
As shown in FIG. 1, the static eliminator of the present embodiment includes a main body 1, an ion generator 3 that includes discharge needles 2 to generate positive and negative ions, and a holder that fixes the ion generator 3 to the main body 1. 4, an air supply pipe 5 for supplying an air flow to the ion generator 3 (corresponding to “air supply means” in the claims), and a power supply unit 6 for applying an AC voltage to the discharge needle 2. Prepare.
[0011]
The main body 1 is formed with an air guide path 11 and an accommodation hole 12 that communicates with the air guide path 11 and accommodates the ion generator 3. One end of the air guide path 11 in the housing of the main body 1 is formed. An air supply pipe 5 is attached to the side. The housing hole 12 has a circular cross section, and the diameter thereof is relatively increased from the center in the axial direction to the front side through the taper portion 12B and the inner wall surface is twisted (not shown). A large diameter portion 12A and a small diameter portion 12C having a relatively small diameter are formed on the rear side. Further, a through-hole 13 that connects the tapered portion 12 </ b> B and the air guide path 11 is formed above the small-diameter portion 12 </ b> C in the main body portion 1.
[0012]
A cylindrical ion generator 3 having an outer diameter substantially the same as that of the small-diameter portion 12C is accommodated in the accommodation hole 12 in a state where the predetermined length is fitted in the small-diameter portion 12C. The holder 4 is screwed with the large diameter portion 12A by a screw thread (which will be described later) formed on the outer peripheral surface thereof (see FIGS. 1 and 2).
An electrode plate 6A is led out from the power supply unit 6 disposed below the main body 1 and is in contact with the discharge needle 2, and the other electrode plate (not shown, ground electrode) Equivalent) is in contact with the holder 4.
[0013]
The ion generator 3 is formed of an insulating material, and a cylindrical portion 31 is formed from a front end surface to a portion behind the center to thereby form a cylindrical open space 32 (in the “ion generation chamber” described in the claims). And an insulating coating is applied to the inner wall surface of the cylindrical portion 31. Between the rear end of the open space 32 and the rear end surface of the ion generator 3, the electrode holding hole 33 and the four air inflow holes 34 (in the “air supply path that faces the ion generation chamber” described in the claims) (Refer to FIG. 1 and FIG. 2).
The electrode holding hole 33 is a through hole having a circular cross section penetrating the axis of the ion generator 3 in the front-rear direction, and the discharge needle 2 protrudes from the open space 32 side toward the open space 32 in the wire holding hole 33. While being held coaxially in the open space 32, a part of the discharge needle 2 is protruded from the rear end face and is in contact with the electrode plate 5A.
The air inflow hole 34 is formed of a through-hole having a circular cross section that is also penetrated around the electric wire holding hole 33 along the axial direction. Each air inflow hole 34 is centered on the electric wire holding hole 33 and the front opening is a cylinder. In the state where they are at the same distance in the radial direction so as to be in contact with the inner wall surface of the portion 31 and are arranged at equal intervals in the circumferential direction, and their openings are in contact with the inner wall surface of the cylindrical portion 31 (See FIGS. 1 and 2).
[0014]
The conductive holder 4 is formed in a substantially cylindrical shape, and the outer diameter thereof is the same as the diameter of the large diameter portion 12 </ b> A, while the inner diameter is substantially the same as the outer diameter of the ion generator 3. Moreover, the collar part 41 is formed in the center part of the front-back direction among the outer peripheral surfaces of the holder 4, and is divided into the holder front part 42A and the holder rear part 42B (refer FIG. 1, FIG. 2).
An annular projecting portion 44 projecting in the inner peripheral direction is formed in the opening 43 (corresponding to the “ion emission port” recited in the claims) of the holder front portion 42A, and the projecting length is a cylindrical portion. It is the same as the wall thickness of 31. Further, the front / rear length of the holder rear portion 42B is shorter than the front / rear length of the large-diameter portion 12A of the main body 1, and the outer peripheral surface is twisted to form the screw and screw formed in the receiving hole 12. It is supposed to be combined. Further, a total of six through holes 45 are formed at equal intervals in the circumferential direction along the axial direction (front-rear direction) in the thick portion between the inner peripheral surface and the outer peripheral surface, and from the front opening 45A. The air flow is jetted (see FIG. 3, the opening 43 is in the “auxiliary air discharge / discharge port” described in the claims, and the through hole 45 is the “air supply path connected to the auxiliary air discharge port”. Corresponds to the composition).
[0015]
Therefore, when the ion generator 3 and the holder 4 are accommodated in the accommodation hole 12, the ion generator 3 is prevented from falling off the main body 1 by abutting against the protruding portion 44, and the insertion depth of the holder 4 is reduced. When the flange portion 41 is restricted, an annular gap 14 is formed between a part of the large diameter portion 12A, the tapered portion 12B, and the ion generator 3, and the through hole 13, the gap 14, and the through hole 45 are formed. Are communicated with each other (see FIG. 5).
The total opening area of each opening 45A is smaller than the opening area of the opening 43, and the flow velocity of the air flow ejected from each opening 45 is the flow velocity of the air flow blown out from the opening 43. Compared to being faster.
[0016]
The configuration of the present embodiment is as described above, and the operation will be described with reference to FIGS. 4 and 5.
First, by supplying power from the power supply unit 6, an alternating voltage is applied between the discharge needle 2 and the holder 4, and when the applied voltage reaches a discharge start voltage that is a voltage for causing corona discharge, corona discharge is performed. And positive and negative ions are alternately generated at the needle tip 2A of the discharge needle 2.
[0017]
On the other hand, an air flow is blown out from the air flow supply pipe 5, and this air flow flows through the air guide path 11 and flows in the open space from the air supply hole 34 along the inner wall surface of the cylindrical portion 31. Here, when the fluid flows along the wall surface, the so-called Coanda effect that the fluid is prevented from diffusing in the direction away from the wall surface, the air flow flowing into the open space 32 gradually moves away from the inner wall surface. It flows while diffusing and is discharged from the opening 44, and the generated positive and negative ions are also ejected from the opening 43 to the outside. Further, due to the Coanda effect described above, an air flow that is drawn into the air flow that flows along the inner wall surface is generated around the discharge needle 2 to form a negative pressure region, so that an increase in air pressure around the discharge electrode is suppressed. Therefore, stable corona discharge is performed.
[0018]
On the other hand, of the air flow from the air guide path 11, the air flow that has flowed into the through hole 13 is blown into the gap 14, and then flows into the six through holes 45 and is injected to the outside through the openings 45A. (See FIG. 5). Since the air flow blown out from the opening 45A is made faster than the flow velocity of the air flow blown out from the opening 43, the air flow containing positive and negative ions blown out from the opening 43 is ejected from these through holes 43. While being drawn into the air flow, it is discharged forward along this air flow.
[0019]
As described above, in the present embodiment, the air flow including ions ejected from the opening 43 is discharged to the outside so as to be drawn into the air flow ejected from the opening 45A, and the air flow discharged from the opening 45A. Can be released in a wide range by being released far away. Accordingly, the corona discharge becomes unstable due to an increase in the flow rate per unit time of the air flow flowing into the open space 32 or the adoption of a method of enlarging the open space 32 (see the prior art). This can be prevented, and furthermore, ions can be ejected over a wide range while avoiding the adverse effect of reducing the amount of ion generation.
In addition, the air flow blown out from the opening 43 is discharged to the outside so as to be drawn into the air flow from the opening 45A, so that the air flow is stagnated in the open space 32 and the atmospheric pressure rises. Can be effectively prevented.
Furthermore, by providing the opening 45A over the entire outer periphery of the opening 43, ions are not discharged in a biased manner and ions can be discharged uniformly.
[0020]
Second Embodiment
In the present embodiment, the through hole 45 is formed in an annular shape, and the opening area of the opening 45A and the opening area of the opening 43 are the same, so that the air jetted from both the openings 43 and 45A The flow velocity is the same. Even if it does in this way, the effect similar to 1st Embodiment is acquired.
[0021]
<Third Embodiment>
A third embodiment according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part same as 1st Embodiment, the overlapping description is abbreviate | omitted, and the description about the same effect | action and effect is also abbreviate | omitted.
In the present embodiment, a communication portion 14 that connects the through hole 13 and the housing surface to the main body 1 is formed, and the auxiliary air supply pipe 7 is inserted into the communication portion 14. The air flow supply device that supplies the air flow to the auxiliary air supply pipe 7 is provided separately from the air flow supply device that supplies the air flow to the air flow supply pipe 5. In the present embodiment, when it is desired to adjust the range in which ions are ejected, the flow rate of the air flow supplied to the auxiliary air supply pipe 7 may be adjusted, and in this way, ions can be produced while stably performing corona discharge. It is possible to adjust the injection range.
[0022]
<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) In the present embodiment, the single through-hole 13 that connects the tapered portion 12B and the air guide path 11 is formed, but a configuration in which two or more through-holes 13 are formed may be used.
[0023]
(2) In addition, the holder has a structure in which a total of six through-holes 45 are provided at equal intervals in the circumferential direction. However, the present invention is not limited to this, and the holder is constituted by five or less through-holes. May be.
[0024]
(3) Moreover, in the said embodiment, it is good also as a structure which provides the throttle mechanism which adjusts the flow volume of an air flow in the through-hole 13 or the through-hole 45. FIG. In this way, it is possible to adjust the ion injection range while rationally generating the air flow for the air inflow hole 34 and the air flow for the through hole 45 by the single air supply pipe 5. Become.
[Brief description of the drawings]
1 is a cross-sectional view of a static eliminator according to a first embodiment. FIG. 2 is an exploded perspective view showing a part of an ion generator, a holder, and a main body. FIG. 3 is a front view of the holder. FIG. 5 is an exploded perspective view showing a part of the ion generator, the holder, and the main body. FIG. 6 is a front view of the holder of the static eliminator according to the second embodiment. FIG. 7 is a cross-sectional view of a static eliminator according to a third embodiment.
DESCRIPTION OF SYMBOLS 1 ... Main-body part 2 ... Discharge needle 3 ... Ion generator 4 ... Holder 13, 45 ... Through-hole 32 ... Open space 34 ... Air inflow hole 43, 45A ... Opening part

Claims (5)

A discharge needle is arranged coaxially with a gap from the ground electrode in a cylindrical ion generation chamber surrounded by the ground electrode, and a voltage is applied between the ground electrode and the discharge needle. In which the corona discharge is generated and air is supplied from one end of the ion generation chamber so that the air containing ions flows out from the ion emission port on the other end of the ion generation chamber.
An auxiliary air discharge port is provided in the vicinity of the ion discharge port, and air is discharged from the auxiliary air discharge port in a direction substantially parallel to the discharge direction of the air flow discharged from the ion discharge port. Static eliminator. 2. The static eliminator according to claim 1, wherein the flow velocity of the air flow discharged from the auxiliary air discharge port is faster than the flow velocity of the air flow discharged from the ion discharge port. The air supply path connected to the auxiliary air discharge port and the air supply path connected to the ion generation chamber are connected to the same air supply means, and the auxiliary air discharge port has a smaller channel cross-sectional area than the ion discharge port. The static eliminator according to claim 2. 4. The static eliminator according to claim 3, wherein a plurality of the auxiliary air discharge ports and the air supply passages connected to the auxiliary air discharge ports are provided so as to surround the ion emission ports. The static eliminator according to any one of claims 1 to 3, wherein the auxiliary air discharge port and the air supply means connected to the auxiliary air discharge port are formed in an annular shape so as to surround the ion emission port. .

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