JPH04223452A - Gas curtain type purge device in dust preventing hood for optical instrument - Google Patents

Abstract

PURPOSE:To offer a gas curtain type purge device inside a dust preventing hood for an optical instrument, which can secure safety even if it is used in a high temp. part, and can effectively prevent the invasion of various kind of dust into a dust preventing hood. CONSTITUTION:A curtain purge nozzle 1 for atomizing inactive gas is provided on one side part of the dust preventing hood 10, simultaneously, a discharging fan 3 is provided on a discharging port 11 provided on the other side part of the above-mentioned dust preventing hood 10, and a nozzle for increasing hood internal pressure 2 is provided between the above-mentioned discharging port 11 and an optical instrument 9. On the other hand, the blow-off pipe 14 of a blower 7 is connected with both ends of the curtain purge nozzle 1, a partition plate 4 is provided inside the dust preventing hood 10, and simultaneously, a gas staying part 5 is provided in the circumference of the discharging port 11.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas curtain type purge device in a dust-proof hood that is attached to optical equipment such as industrial television cameras and photoelectronic switches used in steel mills, chemical factories, and the like.

0002

[Prior Art] Conventionally, as a dustproof hood attached to an optical instrument, an air curtain made of air is installed in the middle of the hood attached to the optical instrument, as disclosed in Japanese Patent Application Laid-Open No. 55-48739. The air inlet is provided with an air inlet for forming the air and a suction port opposite to the air inlet, and the air inlet is configured to reduce the amount of air blown from the air inlet and increase the amount of air sucked out from the air outlet. The air outlet is formed larger than the air outlet, and the blower pipe connected to the air inlet and the air intake pipe connected to the air outlet are connected to a blower, and the air is circulated by the blower to form an air curtain inside the hood. There are known structures configured to allow the formation of

0003

[Problems to be Solved by the Invention] In the case of the conventional dust-proof hood for optical equipment, since air is circulated, it is extremely dangerous to use it in a high-temperature area such as near a heating furnace. Since the air curtain is only dustproof, if the atmospheric pressure outside the air curtain increases, there is a risk that the air curtain will break and dust will enter the hood. In addition, since the suction capacity relies only on the blower, there is a concern that when the amount of blowing increases, the amount of blowing may become larger than the amount of suction. Furthermore, as shown in Figure 7, since the blower pipe is connected to one end of the air inlet, the pressure distribution in the length direction of the air inlet changes greatly and turbulence occurs, which deteriorates the performance of the air curtain. Therefore, in the case of conventional dustproof hoods for optical instruments, dust enters the hood and adheres to the glass surface of the optical instrument, causing the glass surface to fog up.
There is a risk of incorrect operation.

0004

[Means for Solving the Problems] The present invention provides a structure on one side of the dustproof hood 10 in order to ensure safety even when used in a high temperature area and to reliably prevent dust from entering the dustproof hood. Curtain purge nozzle 1 that injects inert gas to
At the same time, a discharge fan 3 is provided at the discharge port 11 provided on the other side of the dust-proof hood 10, and a nozzle 2 for increasing the internal pressure of the hood is provided in the dust-proof hood 10 between the discharge port 11 and the optical device 9. . Also curtain purge nozzle 1
In order to equalize the pressure of the inert gas injected from the
In order to connect the discharge pipe 14 of the blower 7 to both ends of the curtain purge nozzle 1 and to reliably prevent dust from entering the dustproof hood 10, a partition plate 4 is installed inside the dustproof hood 10.
In addition, a gas reservoir portion 5 is provided around the discharge port 11.

[0005]

[Embodiment] Figs. 1 and 2 show a gas curtain type purge device in a dustproof hood for optical equipment according to an embodiment of the present invention, Figs. 3 and 4 show a curtain purge nozzle 1, and Figs. 5 and 6 1 shows a nozzle 2 for increasing internal pressure. The base end of a dustproof hood 10 that surrounds the lens is attached to an optical device 9 consisting of an industrial television camera, and a curtain purge nozzle 1 for forming a curtain of inert gas is installed at the middle upper part of the dustproof hood 10. is arranged and fixed so as to extend in the left-right direction, and the dust-proof hood 10
A discharge port 11 extending in the left-right direction at a position facing the curtain purge nozzle 1 is provided at the middle lower portion of the dust-proof hood 10, and a gas reservoir portion 5 surrounding the entire circumference of the discharge port 11 is provided at the bottom of the dust-proof hood 10. furthermore, the gas reservoir part 5
A partition plate 4 projecting upward is fixed to the upper edge of the optical device 9 side, and a nozzle 2 for increasing the internal pressure of the hood is fixed to the base end of the lower part of the dustproof hood 10.

A plurality of discharge fans 3 are provided in the discharge port 11.
is arranged, the suction pipe 12 of the blower 7 is connected to the discharge port 11, the suction pipe 12 is provided with a filter 8 and a flow rate indicating adjustment device 6, and the discharge pipe 13 of the blower 7 is connected to a nozzle for increasing the internal pressure of the hood. A flow rate indicating adjustment device 16 is provided at a portion of the discharge pipe 13 connected to both ends of the nozzle 2, and the discharge pipe 14 of the blower 7 is connected to both ends of the curtain purge nozzle 1. is,
Further, a curtain purge nozzle 1 in the discharge pipe 14
A flow rate indicating and adjusting device 17 is provided at a portion connected to both ends of the flow rate control device 17 . The discharge pipe 14 is provided with an inert gas supply port 15 having a control valve 27, and an inert gas such as nitrogen gas is supplied from the inert gas supply port 15. Further, the tip of the dustproof hood 10 is connected to a monitoring hole of the heating furnace 18, for example.

FIGS. 3 and 4 show the curtain purge nozzle 1.
In this structure, an inner tube 19 is arranged approximately concentrically within an outer tube 20 with a slit, a flange 21 is bent and connected to the edge of the slit in the outer tube 20 with a slit, and each flange 21 An injection port 22 is provided between the
In addition, a large number of jet nozzle width adjustment screws 23 arranged at intervals in the longitudinal direction of the flange are inserted into each flange 21, so that the pressure of the inert gas jetted from the nozzle nozzle 22 is adjusted to the entire length L of the curtain purge nozzle 1. The width of the injection port 22 is adjusted by the screw 23 so that a constant flow rate flows in the longitudinal direction of the flange. Further, both ends of the inner tube 19 are closed, and the inner tube 19 and the outer tube 20 with a slit are connected via a connecting member (not shown), and the inner tube 19 and the outer tube 20 with a slit are connected to each other via a connecting member (not shown).
A discharge pipe 14 is connected between the two.

FIGS. 5 and 6 show the structure of the nozzle 2 for increasing the internal pressure of the hood, in which an inner tube 24 and an outer tube 25 are arranged concentrically and connected through a connecting member (not shown). A large number of injection slits 26 extending in the longitudinal direction of the outer tube are provided in a portion of the outer tube 25 that is connected and disposed inside the dustproof hood, and furthermore, a discharge slit 26 is provided between the inner tube 24 and the outer tube 25. Pipe 13 is connected. Further, in order to prevent uneven pressure distribution as shown in FIG. The inner diameter of the discharge pipe 14 is set larger than the outer diameter, and the inner diameter of the discharge pipe 13 is set larger than the outer diameter of the inner pipe 24.

In the gas curtain type purge device in the dustproof hood of the present invention, when the blower 7 is operated and the exhaust fan 3 is rotated to supply inert gas from the inert gas supply port 15, the inert gas is is blown from the curtain purge nozzle 1 toward the discharge port 11 to form a curtain of inert gas in the dustproof hood 10, and inert gas is also blown into the dustproof hood 10 from the nozzle 2 to form a gas curtain. Since the pressure inside the gas curtain becomes high, the gas curtain will not be broken even if the atmospheric pressure outside the gas curtain becomes a little high.Therefore, it is used in steel plants and factories with bad atmospheres where the atmospheric pressure changes slightly. When a dustproof hood having the gas curtain type purge device is attached to an industrial television camera, it is possible to prevent dust, metal vapor, etc. in the atmosphere from entering the dustproof hood 10.

Even if dust should pass through the gas curtain and try to enter the optical equipment 9 side, the intrusion is prevented by the partition plate 4 and the inert gas injected from the nozzle 2. In addition, the dust that has entered the discharge port 11 is removed by the discharge fan 3.
The gas is transferred toward the blower 7 by the suction force of the blower 7 and filtered by the filter 8, so that clean inert gas is injected from the curtain purge nozzle 1.

[0011] Also, a gas reservoir 5 is provided for safety.
can accumulate a certain amount of blown gas, and furthermore, the flow rate balance can be visually confirmed by the flow rate indicating adjustment devices 6, 16, and 17. Furthermore, since the gas in the dustproof hood 10 is forcibly discharged by the discharge fan 3 provided at the discharge port 11, the amount blown in does not exceed the amount discharged. Since the air curtain type purge device of the present invention circulates inert gas, it can be installed in high-temperature areas such as heating furnaces, and is therefore effective for use in steel plants, chemical factories, and the like.

0012

According to the present invention, since a gas curtain is formed by injecting inert gas from the curtain purge nozzle 1, it is safe to use the optical instrument 9 equipped with the dustproof hood 10 in a high temperature area. In addition, a discharge fan 3 is provided at the discharge port 11 facing the curtain purge nozzle 1, and a nozzle 2 for increasing the internal pressure of the hood is provided in the dust-proof hood 10 between the discharge port 11 and the optical equipment 9, so that the external atmospheric pressure is reduced. Therefore, it is possible to form a strong gas curtain against dust, and therefore, it is possible to effectively prevent dust from entering into the dustproof hood 10. Furthermore, by connecting the discharge pipe 14 of the blower 7 to both ends of the curtain purge nozzle 1, the pressure distribution of the inert gas injected from the curtain purge nozzle 1 can be changed to the pressure distribution of the air injected from the inlet of a conventional dustproof nozzle. It can be made more uniform by comparison, and the discharge port 1
A partition plate 4 is provided on the optical equipment side of 1, and a discharge port 11 is provided.
By providing the gas reservoir 5 around the dustproof hood 10, it is possible to reliably prevent dust from entering into the dustproof hood 10.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view of a gas curtain type purge device in a dustproof hood for optical equipment.

FIG. 2 is a longitudinal sectional front view of the gas curtain type purge device.

FIG. 3 is a perspective view of a curtain purge nozzle.

FIG. 4 is a cross-sectional view of a curtain purge nozzle.

FIG. 5 is a perspective view of a nozzle for increasing the internal pressure of the hood.

FIG. 6 is a sectional view of a nozzle for increasing the internal pressure of the hood.

FIG. 7 is a diagram showing the pressure distribution of the air inlet in a conventional dustproof hood.

[Explanation of symbols]

1 Curtain purge nozzle 2 Nozzle for increasing hood internal pressure 3. Discharge fan 4 Partition plate 5 Gas reservoir part 6 Flow rate indicator adjustment device 7 Blower 8 Filter 9. Optical equipment 10 Dustproof hood 11 Discharge port 12 Suction tube 13 Discharge pipe 14 Discharge pipe 15 Inert gas supply port 16 Flow rate indication adjustment device 17 Flow rate indication adjustment device 18 Heating furnace 19 Inner tube 20 Outer tube with slit 21 Flange 22 Injection port 23 Screw for adjusting the jet nozzle width 24 Inner tube 25 Outer tube 26 Injection slit 27 Control valve

Claims (2)

[Claims] 1. A curtain purge nozzle 1 for forming a gas curtain of inert gas is provided on one side of a dustproof hood 10 attached to the front part of an optical device 9, and a curtain purge nozzle 1 is provided on the other side of the dustproof hood 10. In the section, curtain purge nozzle 1
A discharge port 11 is provided at a position facing the blower, a discharge fan 3 is provided within the discharge port 11, and a nozzle 2 for increasing the internal pressure of the hood is provided between the discharge port 11 and the optical device 9. The suction pipe 12 of No. 7 is connected to the discharge port 1.
1, a discharge pipe 13 of the blower 7 is connected to the nozzle 2, a discharge pipe 14 of the blower 7 is connected to both ends of the curtain purge nozzle 1, and an inert pipe is connected to the suction pipe 12 or the discharge pipe of the blower 7. A gas curtain type purge device inside a dustproof hood for optical equipment, which is provided with a gas supply port 15. 2. A curtain purge nozzle 1 for forming a gas curtain of inert gas is provided on one side of a dustproof hood 10 attached to the front part of the optical device 9, and a curtain purge nozzle 1 is provided on the other side of the dustproof hood 10. In the section, curtain purge nozzle 1
An exhaust port 11, a gas reservoir 5, and an exhaust fan 3 are provided at a position facing the gas reservoir 5, and a partition plate 4 is provided between the gas reservoir 5 and the optical device 9. A nozzle 2 for increasing the internal pressure of the hood is provided between the hood and the hood 9;
The suction pipe 12 of the blower 7 is connected to the discharge port 11, the discharge pipe 13 of the blower 7 is connected to the nozzle 2, the discharge pipe 14 of the blower 7 is connected to the curtain purge nozzle 1, and the suction pipe of the blower 7 is connected to the curtain purge nozzle 1. 12 or a gas curtain type purge device in a dustproof hood for optical equipment, in which an inert gas supply port 15 is provided in the discharge pipe.