JP7654965B2 - Air purifiers - Google Patents

Description

The present invention relates to an air purifier equipped with a high-pressure mercury lamp.

Conventionally, optical air purifiers that use ultraviolet lamps are known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 61-279248

In recent years, the use of high-pressure mercury lamps as the light source for air purifiers has been considered. High-pressure mercury lamps have a higher output than other light sources, making it possible to purify the air in a short time. On the other hand, high-pressure mercury lamps require forced cooling because they become very hot during use. For example, when forced cooling is performed using air, the high-pressure mercury lamp becomes overcooled, causing the light emission to become unstable, and there is a risk that the desired sterilization performance cannot be achieved.

Therefore, the object of the present invention is to suppress the instability of light emission caused by supercooling in air purifiers that use high-pressure mercury lamps.

An air purifier according to one aspect of the present invention includes a high-pressure mercury lamp having a housing that houses electrodes, a blower that blows air toward the high-pressure mercury lamp, and a wall that covers the housing and is disposed on at least one of the upstream and downstream sides of the housing in the direction of the airflow.

The air purifier according to the present invention can prevent overcooling of high-pressure mercury lamps and suppress instability of light emission.

FIG. 1 is an explanatory diagram showing the appearance of an air purifier according to an embodiment. 1 is a schematic cross-sectional view showing an internal structure of an air purifier according to an embodiment. FIG. 2 is a schematic cross-sectional view showing a schematic configuration of an ultraviolet irradiating unit. 10 is a schematic cross-sectional view showing a schematic configuration of an ultraviolet irradiator in an air purifier according to Modification 1. FIG. FIG. 11 is a schematic cross-sectional view showing a wall portion separate from the lamp holder in an air purifier according to Modification 2.

Below, an air purifier according to an embodiment of the present invention will be described with reference to the drawings. Note that the embodiments described below are comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present invention. Furthermore, each figure in the attached drawings is a schematic diagram and is not necessarily an exact illustration. Furthermore, the same reference numerals are used for the same or similar components in each figure.

In the following description and drawings, the width direction of the air purifier 10 and the axial direction (longitudinal direction) of the high-pressure mercury lamp 31 provided in the air purifier 10 are defined as the X-axis direction. The depth direction of the air purifier 10 is defined as the Y-axis direction. The height direction of the air purifier 10 is defined as the Z-axis direction. These X-axis, Y-axis, and Z-axis directions intersect with each other (orthogonal in this embodiment). For this reason, the XY plane is parallel to the horizontal plane. In the following description, for example, the positive X-axis direction indicates the side of the X-axis arrow (one side), and the negative X-axis direction indicates the opposite side to the positive X-axis direction (the other side). The same applies to the Y-axis and Z-axis directions.

In addition, expressions indicating relative directions or attitudes, such as parallel and perpendicular, also include cases where the direction or attitude is not strictly that. For example, saying that two directions are parallel does not only mean that the two directions are completely parallel, but also means that the directions are substantially parallel, that is, that there is a difference of, for example, about a few percent.

(Embodiment)
[Air purifier]
First, the configuration of an air purifier 10 according to the present embodiment will be described. Fig. 1 is an explanatory diagram showing the external appearance of the air purifier 10 according to the embodiment, and Fig. 2 is a schematic cross-sectional view showing the internal structure of the air purifier 10 according to the embodiment. Specifically, Fig. 1(a) is a front view of the air purifier 10, and Fig. 2(a) is a schematic cross-sectional view corresponding to Fig. 1(a). Fig. 1(b) is a side view of the air purifier 10, and Fig. 2(b) is a schematic cross-sectional view corresponding to Fig. 1(b).

As shown in Figures 1 and 2, the air purifier 10 includes a housing 20, an ultraviolet ray irradiation unit 30, an air blower unit 40, and a power supply circuit unit 50.

The housing 20 is a rectangular box-shaped case that houses the ultraviolet irradiation unit 30, the blower unit 40, and the power circuit unit 50. A plurality of casters 21 are provided on the bottom of the housing 20, and the casters 21 allow the housing 20 to move freely on the floor surface. In the housing 20, a pair of side wall parts 22, 23 facing each other in the X-axis direction are provided with an intake port 24 for taking in outside air and an exhaust port 25 for exhausting purified air. In the housing 20, the blower unit 40 is disposed near the intake port 24. When the blower unit 40 is driven, an air flow f is generated in the housing 20, which takes in outside air from the intake port 24 into the housing 20 and exhausts it from the exhaust port 25. In addition, the power circuit unit 50 is disposed at the bottom inside the housing 20. The power circuit unit 50 is a power supply unit that supplies power to the blower unit 40 and the high-pressure mercury lamp 31 (described later).

The ultraviolet ray irradiation unit 30 is a part that purifies the air taken into the housing 20 by irradiating the air with ultraviolet rays. Specifically, the ultraviolet ray irradiation unit 30 reduces or inactivates viruses, bacteria, and the like present in the air by irradiating light including the 200 nm to 280 nm wavelength band (UV-C).

Figure 3 is a schematic cross-sectional view showing the general configuration of the ultraviolet ray irradiation unit 30 according to the embodiment. As shown in Figure 3, the ultraviolet ray irradiation unit 30 includes a high-pressure mercury lamp 31, a pair of lamp holders 32 and 33, and a duct portion 34.

The high-pressure mercury lamp 31 is a lamp that uses light emission by discharge in mercury vapor pressure of 1 atmosphere or more, and emits light including the above-mentioned 200 nm to 280 nm wavelength band (UV-C). The high-pressure mercury lamp 31 is equipped with a long arc tube 311, a pair of electrodes 314, 315 housed in the arc tube 311, and a pair of bases 312, 313 provided at both ends of the arc tube 311. Electrode terminals electrically connected to the electrodes 314, 315 protrude from each of the bases 312, 313. Each of the bases 312, 313 may be provided with a lead wire electrically connected to the electrodes 314, 315.

The arc tube 311 has both ends that are smaller in diameter than the center, and the electrodes 314, 315 are housed in the narrowed portions at both ends. Thus, both ends of the arc tube 311 are housings 316, 317 that house the electrodes 314, 315. The portion of the arc tube 311 between the housings 316, 317 is a straight tube. The bases 312, 313 may have a structure in which an electrode terminal is provided at the tip, or a structure in which a lead wire is drawn out to the outside. The high-pressure mercury lamp 31 is housed in the duct portion 34, and is arranged so that its axial direction is along the X-axis direction.

The pair of lamp holders 32, 33 are mechanically connected to the bases 312, 313 of the high-pressure mercury lamp 31 to hold the high-pressure mercury lamp 31 in a predetermined position. The pair of lamp holders 32, 33 are electrically connected to the power supply circuit unit 50 and supply power to the electrode terminals provided on the bases 312, 313 of the high-pressure mercury lamp 31. Each lamp holder 32, 33 is formed in an approximately cylindrical shape, and the tip of each base 312, 313 is attached inside it. Therefore, the base end of each base 312, 313 is exposed from each lamp holder 32, 33. Since the outer diameter of each lamp holder 32, 33 is larger than the outer diameter of each storage section 316, 317, when viewed in the axial direction of the high-pressure mercury lamp 31 (viewed in the X-axis direction), each storage section 316, 317 fits within each lamp holder 32. In other words, each lamp holder 32, 33 covers each storage section 316, 317 when viewed in the X-axis direction.

The duct section 34 is housed in the housing 20 and is a section that forms an air flow path from the intake port 24 to the exhaust port 25. The duct section 34 is arranged in the housing 20 with its axis parallel to the X-axis direction. As a result, the flow direction of the airflow f flowing in the duct section 34 is along the X-axis direction. The high-pressure mercury lamp 31 is arranged in the duct section 34. The high-pressure mercury lamp 31 is arranged with its axis roughly coaxial with the axis of the duct section 34. In other words, the high-pressure mercury lamp 31 is arranged so that its axis is along the flow direction of the airflow f. As a result, the airflow f flows smoothly around the light-emitting tube 311 of the high-pressure mercury lamp 31.

Furthermore, if the high-pressure mercury lamp 31 is tilted relative to the horizontal plane, the mercury vapor in the light-emitting tube 311 will be biased toward the lower housing section. This bias is undesirable in terms of providing stable light-emitting performance. In this embodiment, the high-pressure mercury lamp 31 is arranged so that its axial direction is along the flow direction of the air flow f, that is, the X-axis direction. Since the X-axis direction is parallel to the horizontal plane, the high-pressure mercury lamp 31 is arranged in a position that is not tilted relative to the horizontal plane. This makes it less likely that the mercury vapor in the light-emitting tube 311 will be biased, allowing for stable light-emitting performance.

The duct section 34 comprises a first tube section 341 and a pair of second tube sections 342, 343. The first tube section 341 is a section formed in a substantially cylindrical shape, and surrounds the entire circumference of the arc tube 311 of the high-pressure mercury lamp 31 when viewed in the X-axis direction. The second tube sections 342, 343 are provided continuously at both ends of the first tube section 341, respectively.

The second tube section 342 is a frustum-shaped cylindrical section that continues to the upstream end of the first tube section 341 in the direction of the airflow f. The area between the second tube section 342 and the air intake port 24 is also surrounded by a wall body 28, forming a flow path for the airflow f (see FIG. 2). The blower section 40 is disposed within this wall body 28. Also disposed within the second tube section 342 are the lamp holder 32 and the housing section 316 for the light-emitting tube 311 of the high-pressure mercury lamp 31 connected to the lamp holder 32.

The inner surface of the second pipe section 342 is a tapered surface 342a that gradually narrows toward the first pipe section 341. That is, in the second pipe section 342, the internal dimension of the upstream end is the largest, and the internal dimension of the downstream end is the smallest. Since the downstream end of the second pipe section 342 is continuous with the first pipe section 341, the internal dimension of the downstream end is equal to the internal dimension of the first pipe section 341. In this way, the internal dimension of the first pipe section 341 is smaller than the maximum internal dimension of the second pipe section 342. Also, the internal dimension of the first pipe section 341 is equal to or smaller than the minimum internal dimension of the second pipe section 342.

The second tube section 343 is a frustum-shaped cylindrical section that continues to the end of the first tube section 341 on the downstream side of the airflow f. The area between the second tube section 343 and the exhaust port 25 is also surrounded by a wall body 29, forming a flow path for the airflow f (see FIG. 2). The power supply circuit section 50 is disposed below this wall body 29. Also disposed within the second tube section 343 are the lamp holder 33 and the housing section 317 for the light-emitting tube 311 of the high-pressure mercury lamp 31 connected to the lamp holder 33.

The inner surface of the second pipe section 343 is a tapered surface 343a that gradually narrows toward the first pipe section 341. That is, in the second pipe section 343, the inner dimension of the downstream end is the largest, and the inner dimension of the upstream end is the smallest. Since the upstream end of the second pipe section 343 is continuous with the first pipe section 341, the inner dimension of the upstream end is equal to the inner dimension of the first pipe section 341. In this way, the inner dimension of the first pipe section 341 is smaller than the maximum inner dimension of the second pipe section 343. Also, the inner dimension of the first pipe section 341 is equal to or smaller than the minimum inner dimension of the second pipe section 343.

[Air flow]
Next, a description will be given of the flow of airflow f in the duct portion 34 that is generated by driving the blower 40. The airflow f is the flow of air from the intake port 24 to the exhaust port 25 in the housing 20. Specifically, it is the flow of air that enters from the intake port 24, passes through the wall 28, the duct portion 34, and the wall 29, and is exhausted from the exhaust port 25.

The airflow f that has passed through the wall body 28 passes through the second tube section 342 on the upstream side of the duct section 34. At this time, the airflow f is introduced into the first tube section 341 and guided to the light-emitting tube 311 of the high-pressure mercury lamp 31 while gradually increasing its flow speed due to the tapered surface 342a of the second tube section 342. As a result, the airflow f, whose flow speed has increased within the first tube section 341, effectively cools the portion of the light-emitting tube 311 between the respective housing sections 316, 317. This makes it possible to control the mercury vapor pressure within the light-emitting tube 311 and to protect the light-emitting tube 311.

The upstream lamp holder 32 is disposed at a position upstream of the storage section 316, and covers the storage section 316 when viewed in the X-axis direction. Therefore, the lamp holder 32 blocks the airflow f toward the storage section 316, causing the airflow f to stagnate near the storage section 316. This stagnation suppresses the cooling effect of the storage section 316. This makes it possible to suppress a decrease in temperature of the electrode 314 inside the storage section 316 and stabilize the emission of thermoelectrons.

The airflow f that has passed through the first pipe section 341 passes through the downstream second pipe section 343. At this time, the airflow f is introduced into the wall body 29 while gradually weakening its flow rate due to the tapered surface 343a of the second pipe section 343, and is finally exhausted from the exhaust port 25 to the outside of the housing 20.

Here, the downstream lamp holder 33 is disposed at a position downstream of the storage section 317, and covers the storage section 317 when viewed in the X-axis direction. The lamp holder 33 turns the airflow f into turbulence, blocking the airflow f from passing smoothly through the storage section 317. In particular, in the lamp holder 33, the flow rate of the airflow f is weakened by the tapered surface 343a of the second tube section 343, so the turbulence generation effect is also high. As a result, the airflow f stagnates near the storage section 317, suppressing the cooling effect of the storage section 317. This makes it possible to suppress the temperature drop of the electrode 315 in the storage section 317 and stabilize the emission of thermoelectrons.

[Effects, etc.]
As described above, the air purifier 10 of this embodiment comprises a high-pressure mercury lamp 31 having storage sections 316, 317 which house electrodes 314, 315, a blower section 40 which blows airflow f towards the high-pressure mercury lamp 31, and wall sections (lamp holders 32, 33) which are arranged upstream and downstream of the storage sections 316, 317 in the flow direction of the airflow f and cover the storage sections 316, 317.

With this, the walls (lamp holders 32, 33) for stagnating the airflow f are provided on the upstream side of the storage section 316 and the downstream side of the storage section 317, respectively, thereby suppressing the cooling of each storage section 316, 317. Therefore, the temperature drop of the electrodes 314, 315 in each storage section 316, 317 is suppressed, and the emission of thermoelectrons can be stabilized. In this way, overcooling of the high-pressure mercury lamp 31 can be suppressed, and the destabilization of the light emission can be suppressed.

The wall portion is also provided on lamp holders 32 and 33 that hold a high-pressure mercury lamp 31.

As a result, the lamp holders 32 and 33 can stagnate the airflow f near the housing sections 316 and 317, so that overcooling of the high-pressure mercury lamp 31 can be suppressed without the need for a separate, dedicated wall section.

The high-pressure mercury lamp 31 is also arranged so that its axial direction is aligned with the flow direction of the airflow f.

As a result, the high-pressure mercury lamp 31 is arranged so that its axial direction is aligned with the flow direction of the airflow f, so that the airflow f can flow smoothly around the light-emitting tube 311 of the high-pressure mercury lamp 31. This improves the cooling of the portion of the light-emitting tube 311 between the housing portions 316 and 317.

The high-pressure mercury lamp 31 is also arranged so that its axial direction is aligned with a horizontal plane.

This ensures that the high-pressure mercury lamp 31 is positioned without tilting relative to the horizontal plane. This also makes it less likely for the mercury in the light-emitting tube 311 of the high-pressure mercury lamp 31 to become unevenly distributed, allowing for stable light-emitting performance.

The air purifier 10 also has a duct section 34 that surrounds the high-pressure mercury lamp 31 and the wall section. The duct section 34 includes a first tube section 341 that surrounds the high-pressure mercury lamp 31, and second tube sections 342 and 343 that are continuous with the upstream and downstream ends of the first tube section 341 in the flow direction. The internal dimensions of the first tube section 341 are smaller than the maximum internal dimensions of the second tube sections 342 and 343.

As a result, since the internal dimensions of the first tube section 341 are smaller than the maximum internal dimensions of the second tube sections 342 and 343, the flow rate of the air flow f in the first tube section 341 can be made faster than that in the second tube sections 342 and 343. Therefore, the arc tube 311 of the high-pressure mercury lamp 31 arranged in the first tube section 341 can be efficiently cooled while preventing overcooling of each of the storage sections 316 and 317.

In addition, the second pipe sections 342 and 343 have tapered surfaces 342a and 343a that gradually narrow toward the first pipe section 341.

As a result, the tapered surfaces 342a, 343a of the second tube sections 342, 343 can smoothly guide the airflow f to the light-emitting tube 311 of the high-pressure mercury lamp 31. This allows the light-emitting tube 311 to be cooled more efficiently.

[Modification 1]
Next, a first modified example of the air purifier will be described. In the following description, the same components as those in the air purifier 10 according to the above embodiment will be denoted by the same reference numerals, and the description thereof will be omitted in some cases.

Figure 4 is a schematic cross-sectional view showing the schematic configuration of the ultraviolet ray irradiation unit 30A in an air purifier according to the first modified example. Specifically, Figure 4 corresponds to Figure 3. As shown in Figure 4, the first modified example differs from the above embodiment in that the ultraviolet ray irradiation unit 30A has a pair of straightening covers 35, 36.

Specifically, the rectifying cover 35 is disposed immediately upstream of the lamp holder 32. The rectifying cover 35 is formed in a shape that tapers away from the lamp holder 32. The rectifying cover 35 is disposed so as to cover the lamp holder 32 when viewed in the X-axis direction. The rectifying cover 35 straightens the airflow f on its way to the lamp holder 32. As described above, the rectifying cover 35 is formed in a shape that tapers away from the lamp holder 32, so it has a high rectifying effect. This allows the airflow f to flow smoothly on its way to the lamp holder 32, stabilizing the overall flow inside the duct section 34.

On the other hand, the rectifying cover 36 is disposed immediately downstream of the lamp holder 33. The rectifying cover 36 is formed in a shape that tapers away from the lamp holder 33. The rectifying cover 36 is disposed so as to cover the lamp holder 33 when viewed in the X-axis direction. The rectifying cover 36 straightens the flow of the airflow f after it passes through the lamp holder 33. As described above, the rectifying cover 36 is formed in a shape that tapers away from the lamp holder 33, so it has a high rectifying effect. This allows the airflow f to flow smoothly after passing through the lamp holder 33, stabilizing the overall flow inside the duct section 34.

The shape of the airflow straightening covers 35 and 36 may be any shape as long as it can straighten the airflow f. In addition, in the first modification, the lamp holders 32 and 33 are provided with the airflow straightening covers 35 and 36, respectively, but the airflow straightening cover may be provided only on one of the lamp holders 32 and 33.

[Modification 2]
Next, a description will be given of modified air purifier 2. In the following description, the same components as those in air purifier 10 according to the above embodiment will be given the same reference numerals, and the description thereof will be omitted in some cases.

Figure 5 is a schematic cross-sectional view showing the wall parts 37, 38 separate from the lamp holders 32, 33 in the air purifier according to the second modification. As shown in Figure 5, in the second modification, the flow direction of the air flow f1 is along the Z-axis direction. The wall part 37 is formed in a cylindrical shape and is arranged in a position surrounding one of the lamp holders 32 and the storage part 316. The wall part 38 is formed in a cylindrical shape and is arranged in a position surrounding the other of the lamp holders 33 and the storage part 317. The wall parts 37, 38 expose the light-emitting tube 311 of the high-pressure mercury lamp 31. Even in this case, the wall parts 37, 38 block the air flow f1 near the storage parts 316, 317 and cause it to stagnate. This makes it possible to suppress the cooling performance of the storage parts 316, 317. Therefore, it is possible to suppress overcooling of the high-pressure mercury lamp 31 and to suppress instability of the light emission.

In the second modification, cylindrical walls 37 and 38 are shown as an example, but any shape may be used as long as the airflow f1 is stagnated in the vicinity of the storage sections 316 and 317. For example, the walls may be flat or curved plates arranged on at least one of the upstream and downstream sides of the airflow f1 in each storage section 316 and 317.

(others)
Although the air purifier 10 according to the embodiment of the present invention has been described above, the present invention is not limited to this embodiment. In other words, the embodiment disclosed herein is illustrative and not restrictive in all respects, and the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the claims.

For example, in the above embodiment, a case has been exemplified in which the wall portions (lamp holders 32, 33) for stagnating the airflow f are provided on both the upstream side of the storage section 316 and the downstream side of the storage section 317. However, the wall portions may be provided only on either the upstream side of the storage section 316 or the downstream side of the storage section 317. Even in this case, a certain degree of cooling suppression effect can be obtained for the storage sections 316, 317.

In addition, in the above embodiment, the lamp holders 32 and 33 are used as walls, but a dedicated wall for stagnating the airflow f may be provided near the storage sections 316 and 317.

In addition, in the above embodiment, the high-pressure mercury lamp 31 is arranged with its axial direction aligned with the flow direction of the air current f, but the axial direction does not have to be aligned with the flow direction of the air current f.

In addition, in the above embodiment, the high-pressure mercury lamp 31 is arranged with its axial direction aligned along a horizontal plane, but the axial direction does not have to be aligned along a horizontal plane.

In addition, in the above embodiment, the duct portion 34 having the first tube portion 341 and the second tube portions 342 and 343 is illustrated, but the duct portion may have any shape as long as it surrounds the high-pressure mercury lamp 31 and the wall portion.

In addition, any combination of the above embodiments and their variations is also included within the scope of the present invention.

10 Air purifier 20 Housing 21 Casters 22, 23 Side wall portion 24 Air intake port 25 Exhaust port 28, 29 Wall body 30, 30A Ultraviolet ray irradiation portion 31 High pressure mercury lamp 32, 33 Lamp holder (wall portion)
34 Duct section 35, 36 Rectifying cover 37, 38 Wall section 40 Blower section 50 Power circuit section 311 Arc tube 312, 313 Base 314, 315 Electrode 316, 317 Storage section 341 First tube section 342, 343 Second tube section 342a, 343a Tapered surface

Claims (7)

a high pressure mercury lamp having a housing portion housing an electrode;
a blower for blowing air toward the high pressure mercury lamp;
a wall portion that is disposed on at least one of an upstream side and a downstream side of the storage portion in a flow direction of the airflow and covers the storage portion ;
a duct portion surrounding the high-pressure mercury lamp and the wall portion,
The duct portion includes a first tube portion surrounding the high-pressure mercury lamp;
a second pipe portion connected to at least one of an upstream end and a downstream end in the flow direction of the first pipe portion,
The first tubular section has an internal dimension that is smaller than the maximum internal dimension of the second tubular section.
Air purifier. a high pressure mercury lamp having a housing portion housing an electrode;
a blower for blowing air toward the high pressure mercury lamp;
a wall portion that is disposed on at least one of an upstream side and a downstream side of the storage portion in a flow direction of the airflow and covers the storage portion;
a flow straightening cover that is disposed on at least one of the upstream side and the downstream side of the wall portion in the flow direction and covers the wall portion;
Air purifier. The air purifier according to claim 1 or 2 , wherein the wall portion is provided on a lamp holder that holds the high-pressure mercury lamp. The air purifier according to any one of claims 1 to 3 , wherein the high-pressure mercury lamp is disposed such that an axial direction of the high-pressure mercury lamp is aligned with a flow direction of the air current. The air purifier according to claim 4 , wherein the high-pressure mercury lamp is disposed so that an axial direction of the high-pressure mercury lamp is aligned along a horizontal plane. The air purifier according to claim 1 , wherein the second pipe portion has a tapered surface that gradually narrows toward the first pipe portion. The air purifier according to claim 2 , wherein the flow straightening cover has a shape that tapers away from the wall portion.

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