JP2512345B2 - Gas curtain type purging device in dustproof hood for optical equipment - Google Patents

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 purging device in a dustproof hood which is attached to optical equipment such as industrial television cameras and optoelectronic switches used in steelworks and chemical plants.

[0002]

2. Description of the Related Art Conventionally, as a dustproof hood mounted on an optical device, an air curtain with air is provided in the middle of the hood mounted on the optical device as disclosed in Japanese Patent Laid-Open No. 55-48739. A blow port for forming and a suction port facing the blow port are provided, and while reducing the amount of air blown from the blow port, the blow port is increased so that the amount of air sucked from the blow port is increased. The air outlet is formed to be larger than that of the air blower, the air blower pipe connected to the blower outlet and the air blower pipe connected to the air outlet are connected to a blower, and the air is circulated by the blower to form an air curtain in the hood. Structures configured to form are known.

[0003]

In the case of the above-mentioned conventional dustproof hood for optical equipment, since air is circulated, it is very dangerous to use it in a high temperature part such as near a heating furnace, and one air curtain is used. Since it is dust-proof only by itself, if the atmospheric pressure on the outside of the air curtain increases, the air curtain may be broken and dust may enter the hood. Further, since the suction capacity depends only on the blower, there is a concern that when the blow rate increases, the blow rate becomes larger than the blow rate. Furthermore, as shown in FIG. 7, since the blower pipe is connected to one end of the blow-in port, the pressure distribution in the lengthwise direction of the blow-in port changes greatly and turbulence occurs, which deteriorates the performance of the air curtain. Therefore, in the case of the conventional dustproof hood for optical equipment, dust invades into the hood and adheres to the glass surface of the optical equipment, causing the glass surface to fog.
There is a risk of erroneous operation.

[0004]

According to the present invention, one side of the dustproof hood 10 is provided in order to ensure safety even when used in a high temperature part and to reliably prevent dust from entering the dustproof hood. Curtain purge nozzle 1 for injecting an inert gas into the room
And a discharge fan 3 is provided in the discharge port 11 provided on the other side of the dustproof hood 10, and a nozzle 2 for increasing the hood internal pressure is provided in the dustproof hood 10 between the discharge port 11 and the optical device 9. . Also, the curtain purge nozzle 1
In order to equalize the pressure of the inert gas injected from,
The discharge pipe 14 of the blower 7 is connected to both ends of the curtain purge nozzle 1, and in order to reliably prevent dusts from entering the dustproof hood 10, the partition plate 4 is provided in the dustproof hood 10.
And the gas reservoir 5 is provided around the exhaust port 11.

[0005]

1 and 2 show a gas curtain type purging device in a dustproof hood for optical equipment according to an embodiment of the present invention, and FIGS. 3 and 4 show a curtain purge nozzle 1.
5 and 6 show the nozzle 2 for increasing the internal pressure. A base end portion of a dustproof hood 10 surrounding a lens is attached to an optical device 9 composed of an industrial television camera, and a curtain purge nozzle 1 for forming a curtain of an inert gas on an upper part in the middle of the dustproof hood 10. Is fixed so as to extend in the left-right direction, and a discharge port 11 extending in the left-right direction is provided in a lower portion in the middle of the dustproof hood 10 at a position facing the curtain purge nozzle 1, and the dustproof hood is provided. A gas reservoir 5 that surrounds the entire circumference of the discharge port 11 is provided in the lower part of 10, and a partition plate 4 protruding upward is fixed to the upper edge of the gas reservoir 5 on the optical device 9 side. Further, a nozzle 2 for increasing the internal pressure of the hood is fixed to the lower base end portion of the dustproof hood 10.

A plurality of discharge fans 3 are provided in the discharge port 11.
, 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 indicator adjusting device 6, and the discharge pipe 13 of the blower 7 is a hood internal pressure increasing nozzle. 2 is connected to both ends of the discharge pipe 13, and a flow rate indicator adjusting device 16 is provided at a portion of the discharge pipe 13 connected to both ends of the nozzle 2. The discharge pipe 14 of the blower 7 is connected to both ends of the curtain purge nozzle 1. Is
Further, the curtain purge nozzle 1 in the discharge pipe 14
A flow rate indicator adjusting device 17 is provided at a portion connected to both ends of the. 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. The tip of the dustproof hood 10 is connected to, for example, a monitoring hole of the heating furnace 18.

3 and 4 show a curtain purge nozzle 1
The inner pipe 19 is arranged substantially concentrically in the outer pipe 20 with slits, and the flanges 21 are bent and connected to the edges of the slits in the outer pipe 20 with slits. An injection port 22 is provided between
In addition, a large number of injection port width adjusting screws 23, which are arranged at intervals in the longitudinal direction of the flange, are inserted into each flange 21, and the pressure of the inert gas injected from the injection port 22 is the total 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 so as to be substantially uniform over the entire length. Further, both ends of the inner pipe 19 are closed, and the inner pipe 19 and the slit outer pipe 20 are connected to each other (not shown).
And the outer tube 2 with a slit connected to the inner tube 19
The discharge pipe 14 is connected between 0 and 0.

FIG. 5 and FIG. 6 show the structure of the nozzle 2 for increasing the internal pressure of the hood, in which the inner pipe 24 and the outer pipe 25 are arranged concentrically and via a connecting member (not shown). A large number of injection slits 26 extending in the longitudinal direction of the outer pipe are provided in a portion of the outer pipe 25 that is connected and arranged in the dustproof hood, and further discharges between the inner pipe 24 and the outer pipe 25. The pipe 13 is connected. Further, in order to prevent the uneven pressure distribution as shown in FIG. 6, the discharge pipes 14 are connected to both ends of the curtain purge nozzle 1, the discharge pipes 13 are connected to both ends of the nozzle 2, and the inner pipe 19 is connected. 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 purging device in the dustproof hood of the present invention, when the blower 7 is operated, the discharge fan 3 is rotated, and the inert gas is supplied from the inert gas supply port 15, the inert gas is discharged. 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 the inert gas is blown from the nozzle 2 into the dustproof hood 10 as well. Since the internal pressure of the gas becomes high, the gas curtain will not be broken even if the atmospheric pressure on the outside of the gas curtain becomes slightly higher, so it is used in steelworks or factories with bad atmosphere where the atmospheric pressure changes slightly. When a dustproof hood equipped with the gas curtain type purging device is attached to an industrial television camera, the dust and metal vapor in the atmosphere are protected. It can be prevented from entering the hood 10.

Even if dust passes through the gas curtain and enters the optical device 9, the invasion is blocked by the inert gas ejected from the partition plate 4 and the nozzle 2. Also, the dust that has entered the discharge port 11 is
Also, the suction force of the blower 7 transfers the blower 7 toward the blower 7, and the filter 8 filters the blower 7. Therefore, a clean inert gas is injected from the curtain purge nozzle 1.

A gas reservoir 5 provided for safety
Is capable of accumulating a certain amount of blown gas, and the flow rate balance can be visually confirmed by the flow rate control devices 6, 16 and 17. Furthermore, since the gas in the dustproof hood 10 is forcibly discharged by the discharge fan 3 provided in the discharge port 11, the blown amount does not exceed the discharged amount. In the air curtain type purging apparatus of the present invention, since the inert gas is circulated, it can be installed in a high temperature part such as a heating furnace, which is effective for use in a steel mill or a chemical factory.

[0012]

According to the present invention, since an inert gas is jetted from the curtain purge nozzle 1 to form a gas curtain, it is safe to use the optical device 9 equipped with the dustproof hood 10 at a high temperature portion. In addition, since the discharge fan 3 is provided at the discharge port 11 facing the curtain purge nozzle 1, and the hood internal pressure increasing nozzle 2 is provided at the dustproof hood 10 between the discharge port 11 and the optical device 9, the external atmospheric pressure is reduced. Therefore, a strong gas curtain can be formed, so that the intrusion of dusts into the dustproof hood 10 can be effectively prevented. Further, 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 air pressure distribution injected from the blowing port of the conventional dustproof nozzle. Can be made uniform compared to the discharge port 1
The partition plate 4 is provided on the side of the optical device 1 and the outlet 11
By providing the gas reservoir 5 around the periphery of the container, it is possible to reliably prevent dust from entering the dustproof hood 10.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a gas curtain type purging device in a dustproof hood for an optical device.

FIG. 2 is a vertical sectional front view of a gas curtain type purging device.

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

FIG. 4 is a 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 cross-sectional view of a hood internal pressure increasing nozzle.

FIG. 7 is a diagram showing a pressure distribution of a blow-in port in a conventional dustproof hood.

[Explanation of symbols]

 1 Curtain Purge Nozzle 2 Nozzle for Raising Inner Pressure of Hood 3 Discharge Fan 4 Partition Plate 5 Gas Reservoir 6 Flow Rate Control Device 7 Blower 8 Filter 9 Optical Equipment 10 Dustproof Hood 11 Suction Port 12 Suction Pipe 13 Discharge Pipe 14 Discharge Pipe 15 No Active gas supply port 16 Flow rate control device 17 Flow rate control device 18 Heating furnace 19 Inner tube 20 Outer tube with slit 21 Flange 22 Injection port 23 Injection port width adjusting screw 24 Inner tube 25 Outer pipe 26 Injection slit 27 Control valve

Claims (2)

(57) [Claims] 1. A curtain purge nozzle 1 for forming a gas curtain of an inert gas is provided on one side of a dustproof hood 10 mounted on the front part of an optical device 9, and the other side of the dustproof hood 10 is provided. Part is provided with an outlet 11 at a position facing the curtain purge nozzle 1, and
An exhaust fan 3 is provided in the exhaust port 11, a hood internal pressure increasing nozzle 2 is provided between the exhaust port 11 and the optical device 9, and a suction pipe 12 of a blower 7 is provided in the exhaust 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 both ends of the curtain purge nozzle 1, and the suction pipe 12 or the discharge pipe of the blower 7 is supplied with an inert gas. A gas curtain-type purging device in a dustproof hood for an optical device provided with a supply port 15. 2. A curtain purge nozzle 1 for forming a gas curtain of an inert gas is provided on one side of the dustproof hood 10 mounted on the front part of the optical device 9, and the other side of the dustproof hood 10 is provided. Part, a discharge port 11, a gas reservoir 5 and a discharge fan 3 are provided at a position facing the curtain purge nozzle 1, and the gas reservoir 5 and the optical device 9 are provided.
Is provided with a partition plate 4, a nozzle 2 for increasing the internal hood pressure is provided between the partition plate 4 and the optical device 9, and the suction pipe 12 of the blower 7 is connected to the discharge port 11, 7 is connected to the nozzle 2, and the blower 7
Of the blower 7 is connected to the curtain purge nozzle 1, and the suction pipe 12 or the discharge pipe of the blower 7 is provided with an inert gas supply port 15.