JPS61220846A - Ultraviolet rays irradiator - Google Patents

Abstract

PURPOSE:To equalize the temperature distribution of tube wall as well as reduce the temperature of the tube wall by eliminating the occurrece of vortex flow on the downwind side of high-pressure discharge lamp by providing a flow regulator between the exhaust port of a reflector and the downwind side of the lamp. CONSTITUTION:A flow regulator 15 is set on the exhaust port 13 side of a reflector 2 on the surface of the downwind side of a high-pressure discharge lamp 1. As air is discharged from the port 13 by a sucker, cool air is flowed into an irradiating port 3 and flows along the surfaces of the lamp 1 and also of the reflector 2 while cooling them. The air flows along the regulator 15 from the surfaces of the lamp 1 and the reflector 2 to the exhaust port 13 and then the controlled air flowing through both sides 16 of the regulator 15 from both sides of the lamp 1 is joined and discharged. Since air controlled by the regulator 15 flows near the surface of the downwind side of the lamp 1, no vortex flow of air occurs.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ultraviolet irradiation device that irradiates ultraviolet rays using a high-pressure discharge lamp.

[Conventional technology]

BACKGROUND ART In printing processes such as printed plywood, printed wiring boards, and newspaper printing, a method is known in which a substrate coated with ultraviolet-curable paint, ink, etc. is irradiated with ultraviolet rays to cure the paint, ink, etc.

In such a method, a high-pressure discharge lamp such as a high-pressure mercury lamp, meth, or halide lamp that irradiates ultraviolet rays also emits heat rays such as visible rays and infrared rays in addition to ultraviolet rays.
The reflector housing the high-pressure discharge lamp, the paint, ink, etc., and the substrate become hot, which burns out the device or inhibits the chemical reaction of ultraviolet curing. Therefore, in general,
A structure is adopted in which the gas around the high-pressure discharge lamp is exhausted and cool air is drawn into the device to remove heat within the device.

However, with such a structure, the windward side of the high-pressure discharge lamp surface is cooled by the cold air, but the vortex is generated on the leeward side, so the heat dissipation effect of the high-pressure discharge lamp surface is small. The temperature distribution on the surface of the high-pressure discharge lamp becomes uneven, and local focusing loss occurs on the leeward side of the high-pressure discharge lamp.

Conventionally, a device described in Japanese Patent Publication No. 55-162811, for example, is known as a means for preventing focal loss due to such eddy currents. This device prevents the generation of vortices by making the distance between the leeward side of the lamp surface and the cooling air suction part of the concave reflector less than 2/3 of the tube diameter of the lamp. However, because the lamp is placed close to the reflector, the temperature near the deepest part of the reflector increases, causing local damage due to thermal distortion. If the lamps are arranged more than 2/3 apart from each other, vortices will occur.

In addition, as a means to prevent the generation of other eddy currents,
There is an apparatus described in Japanese Patent No. 7-31298. In this device, eddy current elimination plates forming a ventilation path along the surface of the lamp are placed facing each other on the leeward side of the lamp, and the eddy current elimination plates prevent the generation of eddies. However, since the eddy current elimination plate is placed on the surface of the lamp, secondary radiation from this eddy current elimination plate increases the temperature of the lamp surface and tends to cause burnout. A vortex is generated, the temperature near the deepest part of the reflector increases, and local damage occurs due to thermal distortion.

[Problem that the invention seeks to solve]

As mentioned above, it is difficult to reliably suppress the generation of vortices, and the temperature of the reflector near the lamp increases, causing local damage due to thermal distortion. The heat dissipation effect of the surface was very small.

The present invention has been made in view of the above-mentioned points, and is intended to eliminate the vortex on the lee side of a high-pressure discharge lamp, reduce the temperature of the tube wall of the high-pressure discharge lamp due to the vortex, and reduce the temperature of the tube wall on the outer peripheral surface of the high-pressure discharge lamp. The object of the present invention is to provide an ultraviolet irradiation device that achieves uniform humidity distribution and improves the reduction in light output of a high-pressure discharge lamp.

(Means for Solving the Problems) The present invention provides a reflector 2 having an exhaust port 13 for sucking and exhausting gas flowing around the high-pressure discharge lamp 1, which is disposed opposite to the high-pressure discharge lamp 1. A side flow member 1 disposed close to the leeward part of the high pressure discharge lamp 1 so as to cause a side flow of gas flowing from the periphery of the high pressure discharge lamp 1 to the exhaust port 13.
5.

[Effect]

The present invention prevents eddy currents generated on the leeward side of a high-pressure discharge lamp by means of a sidestream member.

〔Example〕

Next, one embodiment of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the ultraviolet irradiation device
A rod-shaped high-pressure discharge lamp 1, a pair of reflectors 2 that are disposed opposite to each other along the high-pressure discharge lamp 1 and have a wide opening on the front side, and the reflector 2 is housed and held and the front side is opened to provide illumination aA opening 3. It is composed of a housing 4 that is formed.

The high-pressure discharge lamp 1 includes, for example, a high-pressure discharge lamp, a metal halide lamp, etc., and when the high-pressure discharge lamp 1 discharges, it emits visible light, infrared rays, etc. along with ultraviolet rays.

The reflector 2 is formed of, for example, a metal plate exclusively made of aluminum and has a quadratic curved surface, and reflects the light rays emitted from the high-pressure discharge lamp 1 toward the irradiation opening 3 of the housing 4.

The housing 4 is formed in the shape of a rectangular parallelepiped, and the front and rear ends 2a and 2b of the reflector 2 are held and fixed to holding parts 11 and 12 provided at the front and rear ends inside the housing 4, respectively. An exhaust port 13 is formed at the rear of the housing 4 and at the deepest part of the reflector 2 to suck and exhaust the gas in the space formed by the high-pressure discharge lamp 1 and the reflector 2 using a suction device (not shown). ing.

Further, a side flow member 15 is arranged on the leeward surface of the high pressure discharge lamp 1 so as to face the exhaust port 13 of the reflector 2. The side flow member 15 is made of quartz glass or aluminum, which is the same material as the tube body of the high pressure discharge lamp 1, and has a rectangular cross section, and is held in contact with the leeward surface of the high pressure discharge lamp 1 along its tube length. Fixed.

Next, the effect will be explained.

Due to the discharge of the high-pressure discharge lamp 1, ultraviolet rays are emitted directly from the irradiation aperture 3 and reflected onto the reflector 2.

Along with this discharge of the high-pressure discharge lamp 1, a suction device (not shown) is driven, and the gas that has absorbed the heat generated by the high-pressure discharge lamp 1 in the space constituted by the high-pressure discharge lamp 1 and the reflector 2 is sucked and exhausted from the exhaust port 13. Ru. This exhaust port 1
3, cold air flows in from the irradiation opening 3 and flows along the circumferential surface of the high-pressure discharge lamp 1 and the surface of the reflector 2 while cooling it, and then cools the surface of the high-pressure discharge lamp 1 and the reflector 2. The gas is then flowed along the side flow member 15 and flows to the exhaust port 13, and the restricted gas flowing from both sides of the high pressure discharge lamp 10 through both sides 16 of this side flow member 15 joins and is exhausted. .

Therefore, since the gas flows near the leeward surface of the high-pressure discharge lamp 1 while being restricted by the side flow member 15, no vortex is generated.

In this apparatus, the high-pressure discharge lamp 1 as described in 5.6 is used, and the side stream member 1 is made of quartz glass.
5 was used to measure the temperature distribution at points A to D on the surface of the high-pressure discharge lamp 1, and the results were as shown in the table below.

The temperature at point A, which is the windward part of high-pressure discharge lamp 1, is 650°C.
The temperatures at points , B, and C were 744 to 748°C, and the temperature at point D, which was the leeward part of the high-pressure discharge lamp 1, was 765°C. Therefore, compared to the case where there is no side flow member 15, 1 at points B and C
It was possible to reduce the temperature by ~7°C, and it was also possible to reduce the temperature by 135°C at point D on the leeward side.

Note that, as shown in FIG. 3, the side flow member 15 has a substantially triangular cross section, and both sides 16 thereof are connected to the high pressure discharge lamp 1.
It may be formed in a shape that follows the flow of gas flowing from both sides.

Further, in the above embodiment, the side flow member 15 was placed in contact with the surface of the high pressure discharge lamp 1, but it may be placed close to the surface of the high pressure discharge lamp 1 by about 1 to 2 feet away.
Alternatively, it may be formed integrally on the surface of the high-pressure discharge lamp 1.

In the above embodiment, the reflector 2 is made of a metal plate so that almost all of the light emitted from the high-pressure discharge lamp 1 is reflected, but the reflector 2 is made of quartz glass and has a quadratic curved surface. For example, titanium oxide (TiOz>
, a multilayer interference Wl film consisting of 10 to 60 alternate layers of high refractive index layers made of filled zirconium (ZrOz) and low refractive index layers made of silica (SiOz), magnesium fluoride (HOF2), etc. is deposited. The reflector 2 may be used to effectively reflect ultraviolet rays emitted from the high-pressure discharge lamp 1 to the irradiation opening 3, and allow infrared rays and some visible rays to pass through and be removed.

〔Effect of the invention〕

According to the present invention, since the side flow member is disposed between the exhaust port of the reflector and the leeward side of the high-pressure discharge lamp, it is possible to suppress the generation of eddies that tend to occur on the leeward side of the high-pressure discharge lamp.
It is possible to reduce the temperature of the tube wall on the leeward side of the high-pressure discharge lamp, and to make the iR wall temperature distribution of the high-pressure discharge lamp uniform. It is possible to reduce the ambient temperature and protect the reflector near the high-pressure discharge lamp, which is prone to thermal deterioration.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the ultraviolet irradiation device of the present invention, FIG. 2 is a longitudinal cross-sectional view thereof, and FIG. 3 is a longitudinal cross-sectional view of essential parts showing another embodiment of the present invention. 1. High pressure discharge lamp, 2. Reflector, 13. Exhaust port, 15. Side flow member.

Claims (1)

[Claims] (1) A high-pressure discharge lamp, a reflector disposed opposite to the high-pressure discharge lamp and having an exhaust port for sucking and exhausting gas flowing around the high-pressure discharge lamp, and a reflector located close to the leeward part of the high-pressure discharge lamp. An ultraviolet irradiation device comprising: a flow restriction member disposed to restrict gas flowing from the periphery of the high pressure discharge lamp to the exhaust port.