JP6512502B1 - Nozzle and dry ice injection device - Google Patents

Abstract

An object of the present invention is to provide a nozzle in which dry ice particles can be sprayed to a target at a pressure of a predetermined value or more in a nozzle having an injection hole formed in a long hole shape, in a wider range than before. . A nozzle for dry ice jetting, which jets a jet body including dry ice particles toward a target object, the jet body introducing passage 23 into which the jet body is introduced, and the downstream side of the jet body introducing passage 23 And an elongated hole shaped injection port 30 formed on the downstream side of the throat portion 26 for injecting an injection body, the longitudinal direction of the throat portion 26; The longitudinal direction of the injection port 30 intersects with the axial line X as viewed from the direction of the axis X. [Selected figure] Figure 3

Description

  The present invention relates to a dry ice jetting apparatus that cleans the surface of a target by jetting dry ice particles toward the target.

  BACKGROUND ART Conventionally, a dry ice injection device has been known which injects dry ice particles generated by adiabatically expanding liquefied carbon dioxide into a carrier gas flow.

  In the dry ice injection device, the liquefied carbon dioxide supplied from the liquefied carbon dioxide gas container is adiabatically expanded in the dry ice generating pipe to generate dry ice particles, and the generated dry ice particles are supplied to the dry ice jet nozzle. Introduce into the gas flow and inject.

  In the dry ice injection device, the size and the shape of the injection port are designed according to the injection target. For example, in Patent Document 1, a jet gun (in the same document, described as "slit port") has a shape of an injection port (described as "discharge port" in the same document). Is disclosed.

  When the injection port of the nozzle is in the form of a long hole, the range in which the dry ice particles are sprayed to the object (hereinafter, also simply referred to as the “spraying range”) can be widely formed. Therefore, the processing such as cleaning can be performed efficiently by spraying the dry ice particles onto the target while moving the nozzle or the target in the direction intersecting the wide direction of the spraying range.

Japanese Utility Model Publication No. 05-49258

  In particular, if the spraying range can be broadened and the spraying pressure of the dry ice particles in the spraying range can be made uniform to some extent, processing is efficiently performed by the amount of the wider size of the spraying range. can do.

  However, according to the nozzle of Patent Document 1, although the spray range is formed to a certain extent, since the dry ice particles can not be jetted at a wide angle, the size in the wide direction of the spray range is not so large. Further, in the nozzle structure of Patent Document 1, since the portion where the spray pressure of the dry ice particles exceeds a certain value in the spray range is concentrated at the central portion of the spray range, the processing such as cleaning is actually performed. The effective spraying range is not very large.

  The present invention provides a nozzle having an injection hole formed in an elongated hole shape and capable of forming a wider range in which dry ice particles can be sprayed to a target with a pressure higher than a predetermined value than in the related art. The purpose is

  In order to solve the above-mentioned subject, a nozzle concerning one mode of the present invention is a nozzle for dry ice injection which jets an injection object containing dry ice particles to an object, and the injection object is introduced Injection body introduction passage, a throat portion having a cross-sectional elongated hole formed downstream of the injection body introduction passage, and a long hole injection which is formed downstream of the throat portion and injects the injection body And a longitudinal direction of the throat portion intersects with a longitudinal direction of the injection port as viewed from an axial direction.

  In the nozzle having the above configuration, a first transition in which the cross-sectional shape gradually changes from the cross-sectional shape of the injection body introduction path to the cross-sectional shape of the throat portion between the jet body introduction path and the throat portion A second transition portion is formed between the throat portion and the injection port, the cross-sectional shape gradually changing from the cross-sectional shape of the throat portion to the shape of the injection port, and the throat portion Preferably, the cross section of the throat portion fits inside the cross section of the injection body introduction path when the cross section of the cross section is projected in the axial direction and superimposed on the cross section of the injection body introduction path.

  A dry ice jetting device according to an aspect of the present invention includes any one of the above nozzles.

  According to the present invention, it is possible to form a wider range in which dry ice particles can be sprayed to a target at a pressure equal to or higher than a predetermined value than in the prior art.

It is a sectional view showing an important section of a dry ice injection device concerning this embodiment. It is the figure which looked at the nozzle concerning this embodiment from the side. It is the figure which looked at the nozzle concerning this embodiment from the direction of an axis. It is a longitudinal cross-sectional view of the nozzle shown in FIG. It is a V-V cross-sectional view of FIG. It is the VI-VI sectional view of FIG. It is VII-VII sectional drawing of FIG. It is a VIII-VIII sectional view of FIG. It is the figure which looked at the nozzle made into comparison object in a test from the direction of an axis. It is XX sectional drawing of FIG. It is XI-XI sectional drawing of FIG. It is a perspective view which shows the mode of a test.

<About the whole configuration of the dry ice injection device>
Hereinafter, the dry ice injection device according to the present embodiment will be described with reference to the drawings. Although the present invention is characterized by the nozzle, prior to the description of the nozzle according to the present embodiment, the entire configuration of the dry ice jetting apparatus will be described.

  As shown in FIG. 1, the dry ice injection device 1 includes an injection device main body 2, a liquefied carbon dioxide supply unit 3, a carrier gas supply unit 4 and the like.

  As shown in FIG. 1, the injection device main body 2 includes a joining member 8, a dry ice production pipe 10, a nozzle 20 and the like. The details of the nozzle 20 will be described in detail later.

  The merging member 8 has a merging space 11 inside. In the confluence space 11, the carrier gas supplied through the carrier gas supply path 7 and the dry ice particles flowing out from the dry ice production pipe 10 described later merge. In the present embodiment, dry air is used as a carrier gas. As the carrier gas, a gas having a low dew point temperature can be used, and in addition to the above-described dry air, a nitrogen gas, a carbon dioxide gas, or the like may be used.

  Further, as shown in FIG. 1, a dry ice generating pipe 10 formed of a double pipe is provided in the merging member 8. The dry ice generating tube 10 is connected at its base end to the liquefied carbon dioxide supply path 6 via the orifice plate 13.

  The orifice plate 13 is formed of a thin plate on which one or more ejection holes 16 are formed. For example, the orifice plate 13 is formed with 2 to 5 ejection holes 16 with an inner diameter of 0.1 mm to 0.2 mm. Further, as the orifice plate 13, for example, a disc having a plate thickness of 1 mm is used. The orifice plate 13 is provided at the boundary between the downstream end of the liquefied carbon dioxide supply passage 6 and the dry ice generating tube 10.

  The ejection holes 16 formed in the orifice plate 13 eject the liquefied carbon dioxide supplied from the liquefied carbon dioxide supply path 6. In the present embodiment, liquefied carbon dioxide supplied from the carbon dioxide supply passage 6 to the orifice plate 13 for liquefaction is liquefied carbon dioxide at a low temperature.

  The dry ice production pipe 10 includes an inner pipe 101 and an outer pipe 102 provided on the outer side of the inner pipe 101 with a gap. The tip end portion 101 a of the inner pipe 101 is located on the tip end side of a predetermined length from the tip end portion 102 a of the outer pipe 102. In the present embodiment, the proximal end portion of the outer pipe 102 is fixed to the outer peripheral surface of the inner pipe 101.

  The inside of the inner pipe 101 of the dry ice generating pipe 10 functions as an expansion space 10a. Also, the cross-sectional area of the upstream portion in the dry ice forming tube 10 is an orifice so that liquefied carbon dioxide ejected from the ejection holes 16 of the orifice plate 13 into the expansion space 10a is adiabatically expanded to form hard dry ice particles. The cross-sectional area of the ejection holes 16 formed in the plate 13 is set to be somewhat large.

  The carrier gas supply passage 7 is configured of an internal carrier gas supply passage 7 a formed inside the merging member 8 and an external carrier gas supply passage 7 b formed outside the merging member 8.

  The internal carrier gas supply passage 7 a is formed to supply the carrier gas toward the dry ice generating tube 10. In the present embodiment, the internal carrier gas supply passage 7a forms a linear flow passage, and supplies the carrier gas at a predetermined acute angle toward the straight dry ice tube 10. In other words, the angle of the center line of the internal carrier gas supply passage 7a with respect to the center line of the dry ice generating tube 10 is a predetermined acute angle (30 degrees in the example of FIG. 2). The angle between the center lines is desirably a predetermined acute angle, but may be approximately 90 degrees or a predetermined obtuse angle.

  In the merging space 11, the carrier gas supplied from the carrier gas supply path 7 and the dry ice particles generated in the inner pipe 101 of the dry ice generating pipe 10 merge. An injection path 18 is formed in the joining member 8 and in the nozzle 20 from the joining space 11 to the injection port 30 at the tip of the nozzle 20 of the injection device main body 2. The ice particles are accelerated by the flow of carrier gas and injected from the injection port 30 toward the object.

  The external carrier gas supply passage 7 b is formed from an air pressure source (not shown) to the joining member 8, and is formed to supply the carrier gas into the joining member 8 of the injection device main body 2.

  In the dry ice injection device 1 having the above configuration, when a predetermined operation for operation start is performed, liquefied carbon dioxide is sent to the ejection holes 16 of the orifice plate 13 through the liquefied carbon dioxide supply passage 6 to be liquefied. The carbon dioxide is jetted from the jet holes 16 into the expansion space 10 a in the inner pipe 101 of the dry ice production pipe 10. And liquefied carbon dioxide adiabatically expands in expansion space 10a, and becomes dry ice particles. At the same time, the carrier gas is supplied toward the outer pipe 102 of the dry ice production pipe 10 through the carrier gas supply path 7, and is injected from the injection port 30 through the injection path 18. The dry ice particles flowing out from the inner pipe 101 of the dry ice generating pipe 10 are mixed in the carrier gas flowing toward the injection port 30 in the merging space 11, and are carried on the carrier gas flow, from the injection port 30 to the object It is injected towards. Hereinafter, the carrier gas containing dry ice particles is also referred to as a "projector".

<About the nozzle>
Subsequently, the nozzle 20 will be described. As shown in FIG. 2, the nozzle 20 has a body portion 21 whose outer appearance is formed in a cylindrical shape, and an injection port forming portion 22 formed on the tip end side of the body portion 21. The nozzle 20 is detachably attached to the injection device main body 2 by a detachable member such as a nut. In this embodiment, it is attached using a detachable member 28 such as a nut. Various structures for attaching the nozzle 20 to the injection device body 2 can be selected. For example, the nozzle 20 may be formed directly on the tip of the injector main body 2. The nozzle 20 may be detachable from the injection device main body 2 without using the detachable member 20 such as a nut.

  Inside the nozzle 20, as shown in FIGS. 4-8, as the flow path of the injection body, the injection body introduction path 23, the first transition portion 24, the throat portion 26, and the second transition in this order from the upstream side. The part 27 and the injection port 30 are formed.

  An injection body is introduced into the injection body introduction passage 23. In the present embodiment, the injection body introduction passage 23 forms a straight flow passage having a circular cross section. However, the injection body introduction passage 23 is not limited to a straight flow passage having a circular cross section. For example, the injection body introduction path 23 may be a curved flow path or a flow path having a non-circular cross section.

  The first transition portion 24 forms a flow path connecting the injection body introduction path 23 and the throat portion 26 described later. The cross-sectional shape of the first transition portion 24 gradually changes from the cross-sectional shape of the injection body introduction passage 23 to the cross-sectional shape of the throat portion 26 so that pressure loss does not occur as much as possible.

  The throat portion 26 is formed in the shape of an elongated hole in cross section. In the present embodiment, as shown in FIG. 7, the cross section of the throat portion 26 is formed in an elliptical shape. The cross-sectional shape of the throat portion 26 may be another elongated hole shape, for example, a rectangle, the same shape as the shape of the injection port 30 described later, or the like. Further, when the cross section of the throat portion 26 is projected in the direction of the axis X and superimposed on the cross section of the injection body introduction path 23, the cross section of the throat portion 26 is inside the cross section of the injection body introduction path 23 The throat portion 26 and the injection body introduction passage 23 are formed so as to be accommodated. Therefore, the dimension L in the longitudinal direction of the throat portion 26 is smaller than the diameter D of the injection body introduction passage 23.

  The second transition portion 27 forms a flow path connecting the throat portion 26 and the injection port 30. The cross-sectional shape of the second transition portion 27 gradually changes from the cross-sectional shape of the throat portion 26 to the cross-sectional shape of the injection port 30 so that pressure loss does not occur as much as possible.

  The injection port 30 is formed in a long hole shape as viewed from the direction of the axis X as shown in FIG. In the present embodiment, the shape of the injection port 30 is composed of two line segments parallel to each other and a semicircle connected to both ends of the two line segments. However, the shape of the injection port 30 is not limited to the above shape, and may be another long hole shape, for example, a rectangle, an ellipse, or the like.

  The longitudinal direction of the injection port 30 (hereinafter also referred to as “lateral direction”) is viewed from the direction of the axis X and directed to a direction intersecting the longitudinal direction of the throat portion 26 (hereinafter also referred to as “longitudinal direction”). ing. In the present embodiment, the “crossing direction” is a “crossing direction”. In addition, the position where the injection port 30 and the throat part 26 cross | intersect is each longitudinal direction center part.

  In the present embodiment, the injection port 30 is formed in a substantially square frustum-shaped injection port forming portion 22. In other words, the outer surface around the injection port 30 is formed in a substantially square frustum shape.

  In the nozzle 20, when the injection body is introduced into the injection body introduction passage 23, the injection body moves toward the injection port 30 while accelerating the inside of the first transition portion 24, and the cross section of the injection hole is formed. Pass through the throat section 26. Next, in the second transition portion 27 in which the cross section changes from the longitudinally elongated shape to the gradually elongated shape in the lateral direction, kinetic energy that diffuses laterally to the spray body is applied. Then, the injection body is injected from the injection port 30 toward the object at a wide angle.

  According to the nozzle 20 according to the present embodiment having the above configuration, the longitudinal direction of the throat portion 26 and the longitudinal direction of the injection port 30 intersect with each other when viewed from the axis X direction. The lateral dimension of the throat portion 26 can be reduced without reducing the area. As a result, as shown in FIG. 5, it is possible to easily increase the lateral spread angle θ in the second transition portion 27. In addition, since it is not necessary to reduce the cross-sectional area of the throat portion 26, the flow rate of the injection body passing through the throat portion 26 at a high speed is sufficiently ensured, and the pressure of the dry ice particles to the target is the spreading angle θ (injection It is likely to be even throughout the range of the range).

  Further, according to the nozzle 20 according to the present embodiment, when the cross section of the throat portion 26 is projected in the direction of the axis X and superimposed on the cross section of the injection body introduction path 23, as shown in FIG. Since the throat portion 26 and the injection body introduction path 23 are formed so that the inside of the cross section of the injection body introduction path 23 is formed, as shown in FIG. 4, from the injection body introduction path 23 to the injection port 30 The change of the dimension in the vertical direction (vertical direction in FIG. 4) is slow. As a result, the pressure loss is suppressed, and the spray pressure of the dry ice particles to the target can be increased.

<Comparison test>
The test which compared the nozzle 20 which concerns on this embodiment, and the other nozzle 20A was implemented. In the other nozzle 20A (hereinafter referred to as "the nozzle 20A relating to comparison object"), the longitudinal direction of the injection port 30A and the longitudinal direction of the throat portion 26A face the same direction when viewed from the axis X direction. The test content is explained below.

  The nozzle 20A which concerns on comparison object in FIGS. 9-11 is shown. As shown in FIG. 9, in the nozzle 20A, the longitudinal direction of the injection port 30A and the longitudinal direction of the throat portion 26A face in the same direction as viewed from the axis X direction, and overlap. Further, since the injection port 30A of the nozzle 20A and the throat portion 26A have substantially the same shape and cross sectional area, the cross section of the portion 27A corresponding to the second transition portion 27 of the nozzle 20 according to the present embodiment changes. I did not.

  The parts other than the above are the same in the nozzle 20A and the nozzle 20. That is, the injection body introduction path 23A of the nozzle 20A has the same diameter and length as the injection body introduction path 23 of the nozzle 20. The throat portion 26A of the nozzle 20A has the same shape and cross-sectional area as the throat portion 26 of the nozzle 20. In addition, the injection port 30A of the nozzle 20A has the same shape and cross-sectional area as the injection port 30 of the nozzle 20.

The dimensions and the like of each part of the nozzles 20 and 20A used in the test are as follows. The diameter of each of the injection body introduction paths 23, 23A is 10 mm, and the length of each of the injection body introduction paths 23, 23A is 20 mm. The length of each of the first transition portions 24 and 24A is 6.47 mm. The lengths of the throat portions 26 and 26A are both 1.25 mm, and the cross-sectional areas of the throat portions 26 and 26A are 15.89 mm ² each. The length of each of the portions 27A corresponding to the second transition portion 27 and the second transition portion 27 is 22.2 mm. The cross-sectional area of each of the injection ports 30, 30A is 15.92 mm ² , and the size in the longitudinal direction (lateral direction) of each of the injection ports 30, 30A is 8 mm. The above "length" is the length in the direction of the axis X in each case.

  In the test, a pressure sensitive paper which develops color in response to the applied pressure was used to confirm the longitudinal size of the spray area on the object. The pressure-sensitive paper used is a pre-sheet "for high pressure" (HS) mono-sheet manufactured by Fujifilm Corporation.

  In the test, as shown in FIG. 12, the nozzles 20 and 20A are vertically opposed to the pressure sensitive paper 40, and the distance from the tips of the nozzles 20 and 20A to the pressure sensitive paper 40 is maintained at a constant distance. The nozzles 20 and 20A were moved in a direction parallel to the pressure sensitive paper 40 at a constant speed while ejecting particles. Of course, the direction of the movement is a direction orthogonal to the longitudinal direction of the injection ports 30, 30A. Thereafter, the width W (see FIG. 12) of the portion of the pressure-sensitive paper which has developed a color showing a pressure value higher than a predetermined value was measured.

  As a result of conducting said test, when using nozzle 20 concerning this embodiment, width W was 15 mm. On the other hand, when the nozzle 20A related to comparison was used, the width W was 11.5 mm. From this test result, it is better to use the nozzle 20 according to the present embodiment than to use the nozzle 20A according to the comparison target in a range where the dry ice particles are sprayed to the object at a pressure higher than a predetermined value. It can be said that it will be much wider.

  The present invention can be applied to a nozzle of a dry ice jetting apparatus that cleans the surface of a target by jetting dry ice particles toward the target.

DESCRIPTION OF SYMBOLS 1 dry ice injection apparatus 20 nozzle 23 injection body introduction path 24 1st transition part 26 throat part 27 2nd transition part 30 injection port

Claims (3)

A nozzle for dry ice jet, which jets a jet body including dry ice particles toward an object,
An injection body introduction path into which the injection body is introduced;
An elongated hole shaped throat portion formed in the downstream side of the injection body introduction path;
An elongated hole-shaped injection port formed on the downstream side of the throat portion for injecting the injection body;
Equipped with
The longitudinal direction of the throat portion intersects with the longitudinal direction of the injection port when viewed from the axial direction.
A nozzle characterized by In the nozzle according to claim 1,
Between the injection body introduction path and the throat portion, a first transition portion in which the cross-sectional shape gradually changes from the cross-sectional shape of the injection body introduction path to the cross-sectional shape of the throat portion is formed.
Between the throat portion and the injection port, a second transition portion in which the cross-sectional shape gradually changes from the cross-sectional shape of the throat portion to the shape of the injection port is formed;
When the cross section of the throat portion is projected in the axial direction and superimposed on the cross section of the injection body introduction path, the cross section of the throat portion fits inside the cross section of the injection body introduction path
A nozzle characterized by A dry ice jetting apparatus comprising the nozzle according to claim 1 or 2.

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