JPH0572943U - UV irradiation device - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide an ultraviolet irradiating device which can uniformly cool the surface of a discharge lamp by using a blowing type fan in order to improve cooling efficiency. A discharge lamp, a gutter-shaped elliptical cold mirror that reflects radiation of the discharge lamp, a lamp case that configures the discharge lamp and the gutter-shaped elliptical cold mirror, and a blower duct toward the lamp case. In the ultraviolet irradiation device having a blow-type cooling fan for supplying cooling air through the elliptical cold mirror, a large number of air holes for directing the cooling air to almost the entire surface of the discharge lamp are provided, and the elliptical cold mirror is provided. It is characterized in that there is no wind hole at the position on the major axis of the cold mirror.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to an ultraviolet irradiation device.

[0002]

[Prior Art]

 The ultraviolet irradiation device is used to perform various kinds of processing using ultraviolet rays. For example, it is used to cure coating agents applied to the surface of optical fibers and to cure printing inks.

FIG. 4 is a schematic explanatory view of a conventional ultraviolet irradiation device. First, the configuration will be described. Reference numeral 10 is a rod-shaped electroded discharge lamp that emits ultraviolet rays, 20 is a gutter-shaped elliptical cold mirror that covers the discharge lamp 10, 30 is provided above the discharge lamp 10, and a wind tunnel 50 and a discharge lamp 10 are provided. A partition wall that separates the light irradiation unit, 40 is a suction hole provided in the partition wall 30, 50 is a wind tunnel for sucking hot air and discharging it to the duct 80, and 60 is a lamp that constitutes the wind tunnel 50 and the light irradiation unit. A case, 70 is a light irradiation port provided at the bottom of the lamp case 60, 80 is an exhaust duct for discharging the hot air of the lamp case 60 to the outside, and 90 is a suction type fan. Next, the operation will be described. In the ultraviolet irradiation apparatus of FIG. 4, an irradiation object (not shown) is arranged below the light irradiation port 70 and is irradiated by the direct light of the discharge lamp 10 and the reflected light from the cold mirror 20.

Conventionally, as the discharge lamp 10, a metal halide lamp or a high pressure mercury lamp having a high radiation efficiency of ultraviolet rays is used. These lamps can get quite hot during operation. Then, when the temperature becomes higher than necessary, the quartz glass of the arc tube is devitrified, resulting in a problem that the life is shortened. Generally, in order to solve this problem, a cooling fan 90 of suction type is used to blow cooling air around the discharge lamp 10 through the exhaust duct 80. The flow of this cooling air is shown by the arrow in the figure. Further, in such cooling of the discharge lamp 10, it is known that the cooling effect of the discharge lamp 10 is further increased by increasing the velocity of the cooling air flowing on the surface of the discharge lamp. For this reason, it is also considered to use a blow-type fan instead of the suction-type fan 90. This is because the blow-type cooling fan is much smaller than the suction-type cooling fan in order to obtain the same wind speed. As an example, in a device with a lamp input of 4 kW, in order to obtain a wind speed of 12 to 14 m / sec, a suction type cooling fan requires a rated output of 750 W, while a blowing type cooling fan requires a power output of 300 W. Is enough. Therefore, there is an advantage that the device becomes compact.

[0005]

[Problems to be solved by the device]

 When a blow-type cooling fan is used in the conventional device shown in FIG. 4, there is a large difference in temperature between the surface portion of the lamp to which direct cooling air is blown and the surface portion of the lamp that is not blown. .. As a result, the enclosed metal does not evaporate in the sprayed portion, or the quartz tube devitrifies in the non-sprayed portion.

[0006] The present invention has been made in order to solve such a problem, and uses a blow-type cooling fan to increase the cooling efficiency, and ultraviolet irradiation capable of cooling the entire surface of the discharge lamp almost uniformly. The purpose is to provide a device.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the ultraviolet irradiation device of the present invention comprises a rod-shaped electrode discharge lamp, an elliptic cold mirror having a gutter-shaped cross section for reflecting the emitted light of the discharge lamp in the direction of an object to be irradiated, In the ultraviolet irradiation device having a lamp case surrounding the discharge lamp and the elliptical cold mirror, and a blow-type cooling fan for supplying cooling air to the lamp case through a duct, the elliptical cold mirror includes: A large number of air holes for directing cooling air are provided on almost the entire surface of the discharge lamp, and no air holes are provided on the major axis of the elliptical cold mirror.

[0008]

[Action]

 With such a configuration, since a small blow-type cooling fan is used, the cooling efficiency can be improved, and the surface of the discharge lamp can be cooled substantially uniformly.

[0009]

【Example】

 FIG. 1 is a schematic explanatory view of an ultraviolet irradiation device which is an embodiment of the present invention. FIG. 2 shows a cross-sectional view taken along the line AA shown in FIG. FIG. 3 is a view showing only the elliptical cold mirror 21 and the discharge lamp 10 arranged in the lamp case 60 in FIG. 1 and seen from the irradiation surface side. First, the configuration of an embodiment of the present invention will be described. In the figure, reference numeral 21 denotes an elliptical cold mirror in which a large number of air holes for directing cooling air are provided on almost the entire surface of the discharge lamp 10 and no air holes are provided on the major axis. 41 and 42 are air holes provided in the cold mirror 21 through which cooling air passes, 43 is a metal block for holding the cold mirror 21, 81 is a ventilation duct that sends the cooling air to the lamp case 60, and 91 is a blow-type cooling Show each fan. In addition, the same reference numerals as those in FIG. 4 indicate the same parts. Further, the operation of the ultraviolet irradiation processing is the same as that of the conventional ultraviolet irradiation processing shown in FIG. Next, a method of cooling the discharge lamp in this invention will be described. As an example, a blowing sirocco type cooling fan 91 is used to generate a flow of cooling air. Then, the cooling air is sent to the wind tunnel 50 through the air duct 81, passes through the air holes 41 and 42 of the elliptical cold mirror 21, and the cooling air is made to flow around the discharge lamp 10. The flow of cooling air is shown by the arrows in the figure. As described above, the elliptical cold mirror 21 is provided with air holes 41 and 42 so that the cooling air is uniformly directed to almost the entire surface of the discharge lamp 10.

Here, if the air hole 42 exists in the range H 2 having a certain width on the major axis of the elliptical cold mirror 21, the cooling air that flows through the duct 81 directly appears on the surface B of the discharge lamp 10. Therefore, it is overcooled and falls below the proper temperature. The proper temperature referred to here is the temperature at which the metal for generating ultraviolet rays is enclosed in the discharge lamp 10, the evaporation of the enclosed metal is promoted, and as a result, the light emission spectrum peculiar to the metal is obtained. Say. Further, if the rated output of the cooling fan 91 is reduced so that the temperature on the surface B of the discharge lamp 10 is maintained at an appropriate temperature, then the surface C of the discharge lamp 10 is not cooled as much as necessary. This is the most difficult place to cool the surface C of the discharge lamp 10 due to the influence of the cooling air. As a result, the temperature of the quartz constituting the arc tube near the surface C of the discharge lamp 10 becomes high, causing a problem of devitrification, that is, clouding.

Therefore, the present invention is characterized in that, as shown in FIGS. 2 and 3, the elliptical cold mirror 21 does not have air holes 41 and 42 through which cooling air passes in a range H having a certain width on the major axis. I am trying. As an example, the air hole 41 is in the range of 40 mm to 90 mm in width about the major axis of the elliptical cold mirror 21. Further, it is desirable that the air holes 42 are not within the range of 8 mm around the major axis of the elliptical cold mirror 21. The size of the air holes 41 is preferably about 5Φ to 6Φ, and the size of the air holes 42 is preferably about 2.5Φ to 3Φ. Further, the total area of the air holes 41, 42 through which the cooling air passes is preferably within 10% of the effective reflection area of the elliptic cord mirror 21. By using the elliptical cold mirror 21 having such a configuration, the discharge lamp 10 is cooled uniformly. Further, in this embodiment, the temperature of the surface of the light emitting portion of the discharge lamp 10 is set to, for example, 550 to 850 ° C.

[0012]

As described above, in the ultraviolet irradiation device, a large number of air holes for directing the cooling air are provided, and the elliptical cold miller having no air holes on the major axis is used for spraying. By adopting the mold cooling method, the discharge lamp is cooled uniformly at the proper temperature.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of an ultraviolet irradiation device according to an embodiment of the present invention.

2 shows a cross-sectional view taken along the line AA shown in FIG.

FIG. 3 is a view showing only the elliptical cold mirror and the discharge lamp arranged in the lamp case taken out from the irradiation surface side in FIG.

FIG. 4 is a schematic explanatory view of a conventional ultraviolet irradiation device.

[Explanation of symbols]

 10 Electrode discharge lamp 20 Elliptical cold mirror 21 Elliptical cold mirror 30 Partition 40 Suction hole 41 Wind hole 42 Wind hole 43 Metal block 50 Wind tunnel 60 Lamp case 70 Light irradiation port 80 Exhaust duct 81 Air duct 90 Suction fan 91 Blowing fan H Oval cold Position on the major axis of the mirror

Claims (1)

[Scope of utility model registration request] 1. A rod-shaped electroded discharge lamp, an elliptical cold mirror having a gutter-shaped cross section for reflecting radiation of the discharge lamp toward an object to be irradiated, and a lamp case surrounding the discharge lamp and the elliptical cold mirror. In an ultraviolet irradiation device having a blow-type cooling fan that supplies cooling air toward the lamp case through a duct, the elliptical cold mirror directs cooling air to almost the entire surface of the discharge lamp. There are many air holes
Moreover, the ultraviolet irradiation device is characterized in that the elliptical cold mirror is not provided with a wind hole at a position on the major axis.