JPS593703B2 - air curtain nozzle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a nozzle used for air purging for water removal, steam removal, and dust removal, which is used when measuring the moving speed of an object to be measured using a laser.

When measuring the surface velocity of a steel plate, etc. without contact using a laser, if there is water or steam in the optical path between the sensor and the object to be measured or on the surface of the object to be measured, the laser light will attenuate and accurate measurements will not be possible. There's a problem.

This invention proposes a nozzle for eliminating such problems. The invention will be explained below with reference to the drawings.

FIG. 1 is a schematic diagram showing the operation of the present invention.

In the figure, reference numeral 1 is fixed to a pedestal 2 and is heated by a nozzle in contact with a sensor 3, which has a hollow cylindrical shape through which laser light 4 and reflected light 5 pass. Purge air 7 is blown from a nozzle 1 onto an object to be measured 6 to remove water 8 and steam 9. FIG. 2 is a cross-sectional view showing the details of the nozzle 1, in which 10 is an outer wall of an annular gap 11 for ejecting purge air T from the nozzle tip, and the incoming air 1
The first outer cylinder constitutes the outer wall of the air reservoir 14 and the air intake port 15 to make the pressure of the air 2 and the air 13 the same and the speed of the air ejected from the nozzle tip, and its shape is a hollow cylinder. It is.

16 is located on the hollow inner surface of the first outer cylinder 10, and is an optical path 1 through which the laser beam and the reflected light 5 pass through the hollow cylinder outer surface that constitutes the inner wall of the annular gap 11 and the inner wall of the air reservoir 14.
The first inner cylinder has a hollow cylindrical shape.

The first outer cylinder 10 and the first inner cylinder 16 constitute an air intake 15, an air reservoir 14, an annular gap 11, and a part of the optical path IT. Air 13 is blown out from the annular gap 11 to the object 6 to be measured through the annular gap 11 to create purge air T for removing water and steam. Next, when the purge air T is ejected, the pressure in the optical path IT drops, the purge air □ becomes turbulent, and the rope purge falls.

Optical path 1 to eliminate this problem? It is necessary to place an appropriate amount of auxiliary air 18 inside the tank to prevent a drop in pressure and prevent the purge from falling. Reference numeral 19 is a hollow cylindrical shape, and the outer surface stores air to make the inflow air 20 and the auxiliary air 18 have the same pressure, and the air reservoir 22 is used to equalize the speed of the auxiliary air 18 exiting from several outflow holes 21 around the circumference. This is a second inner cylinder that constitutes an inner wall and a part of the optical path 17.

A second outer cylinder 23 is located on the outer surface of the second inner cylinder 19 and forms the outer wall of the air reservoir 22 and the air intake port 24, and has a hollow cylindrical shape.

The second inner cylinder 19 and the second outer cylinder 23 constitute an air intake port 24 , an air reservoir 22 , and an outflow hole 21 . A suitable amount of auxiliary air 18 is blown out, and the optical path 17 is
This serves to prevent a drop in the internal pressure, prevent the purge air 7 from becoming turbulent, and maintain the purge air. By the way, it is well known that the jet flow that exits the jet nozzle generally spreads at a certain angle.

Therefore, at a position a predetermined distance away from the jet nozzle, interference occurs between the inner jet and the outer jet. Therefore, when removing water and steam with purge air 7, the outer jet may enter the inner jet and steam 19 may mix into purge air 7, so the jetting speed is lower than the jetting speed of purge air 7. It is necessary to prevent steam from getting mixed in by blowing out auxiliary purge air 25. 26 is auxiliary purge air
The outer wall of the annular gap 27 for blowing out the air 25 and the annular gap 2 collect air to make the incoming air 28 and the air 29 the same pressure.
7 and a third outer cylinder constituting the outer wall of the air reservoir 31 and the air intake port 32 for equalizing the speed of air ejected from the plurality of spiral grooves 30, and its shape is a hollow cylinder. be.

A third inner cylinder 33 is located on the hollow inner surface of the outer cylinder 26 and constitutes the inner wall of the annular gap 27, the plurality of spiral grooves 30, and the inner wall of the air reservoir 31, and is hollow in shape. It is cylindrical.

The third outer cylinder 26 and the third inner cylinder 33 have an air intake port 32, an air reservoir 31, an annular gap 27, and a spiral groove 30.
The inflow air 28 is introduced from the air intake port 32, passes through the air reservoir 31, and air 29 is ejected with spiral component force from the spiral groove and the annular gap 27 to create auxiliary purge air 25 and flow into the purge air 7. This prevents steam from entering the tank. Note that the spiral groove 30 is provided not only on the outer wall of the third inner cylinder 33 but also on the inner wall of the third outer cylinder 26 or on both the outer wall of the third inner cylinder 33 and the inner wall of the third outer cylinder 26. It's okay. As described above, the nozzle of this invention creates a double annular air curtain so that the ejection velocity of the inner annular air curtain is higher than that of the outer annular air curtain, and ejects steam from the outer wall annular air curtain through the spiral groove. It is possible to prevent the particles from getting mixed into the purge air by scattering them in the opposite direction.

As described above, according to the present invention, water and steam can be removed from the optical path between the sensor and the object to be measured and from the surface of the object to be measured, thereby making it possible to perform accurate measurements. It goes without saying that the air curtain nozzle according to the present invention can not only remove water and steam, but also dust.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the operation of the present invention, and FIG. 2 is a sectional view showing details of the nozzle, in which 1 is a nozzle, 2 is a pedestal, and 3
is a sensor, 4 is a laser beam, 5 is a reflected light, 6 is an initial region 1 constant, 7 is a purge air, 8 is water, 9 is steam, 10 is a first outer cylinder, 11 is an annular gap, 14 is air 16 is a first inner cylinder, 17 is an optical path, 18 is auxiliary air, 25 is auxiliary purge air, 26 is a third outer cylinder, 30 is a spiral groove, and 33 is a third inner cylinder.

Claims (1)

[Claims] 1. Create a double annular air curtain so that the ejection speed of the inner annular air curtain is greater than the ejection speed of the outer annular air curtain, and allow light to pass inside the inner annular air curtain, while allowing light to pass through the inner annular air curtain. An air curtain nozzle characterized in that the nozzle groove has a plurality of spiral grooves on an outer wall, an inner wall, or an inner and outer wall within an annular groove.