JP2010253522A - Spray nozzle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flat spray nozzle capable of giving anisotropy to width-directional collision force of a discharge flow from a nozzle. <P>SOLUTION: The flat spray nozzle, from which water is discharged, is a descaling nozzle for removing scale from the surface of a steel sheet. In the descaling nozzle, the shape of a discharge hole 15 of its tip end is made an anisotropic shape having major and minor axes, and made an asymmetric shape with respect to the minor axis. The anisotropic shape of the discharge hole may be made an approximately elliptical shape while making the ratio of the long diameter to the short diameter 1.2-3 times. Further, when dividing the shape of the discharge hole into two parts with respect to the minor axis, the areas of the divided parts may be different while making the ratio of the area of the large area part 15a to that of the small area part 15b 1.1-1.5. The shape of the small area part may be a semi-elliptical shape while making the shape of the large area part a curved U-shape. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a flat spray nozzle suitable for a spray nozzle for injecting liquid in a flat pattern, particularly a descaling nozzle for removing scale on the surface of hot-rolled rolled steel, and a carbide tip useful for this nozzle. .

  Hot-rolled steel is manufactured by heating a steel slab to about 1100 to 1400 ° C. in a heating furnace in an oxidizing atmosphere and hot rolling with a rolling mill. By the heating in the heating furnace, a scale composed of iron oxide is generated on the surface of the steel slab, and when hot rolling is performed without removing the scale, scale flaws are generated on the surface of the rolled steel sheet, thereby reducing the product value. . In order to remove such a scale, a descaling nozzle for injecting water at a high pressure is used. In addition, since the steel plate produced industrially is wide, a several descaling nozzle is normally used with respect to one steel plate.

  FIG. 6 is a schematic diagram illustrating an example of how the descaling nozzle is used. In FIG. 6, the plurality of descaling nozzles 21 are arranged in parallel to the descaling header 24 at a predetermined interval so that the direction of the discharge flow 22 is substantially perpendicular to the steel plate 25, and the X direction A water discharge flow 22 is jetted from each nozzle 21 to the steel plate 25 at a high pressure with respect to the steel plate 25 continuously conveyed. At this time, for example, the shape of the ejection hole of the nozzle 21 is normally reflected in the ejection region (ejection pattern), and the shape of the ejection hole is an elliptical shape having a major axis in a direction substantially perpendicular to the X direction. In this case, the jet region 23 of the jetted water also has a linear pattern extending in the major axis direction of the elliptical shape of the discharge hole. Further, in this usage mode of the descaling nozzle, in order to cause the discharge flow (high pressure jet flow) 22 to collide with the entire surface of the steel plate 25, the end portions of the adjacent jet regions 23 are overlapped to form a wrap region 23a. Thus, there has been proposed a method for eliminating the breaks in the ejection region 23 and improving the removal efficiency of the scale.

  For example, in Japanese Patent Application Laid-Open No. 5-261426 (Patent Document 1), descaling rows are arranged in a plurality of stages, and the wrapping area between the ejection patterns of the respective descaling nozzles is set to 5 to 30 mm in each descaling operation stage. A descaling system has been proposed.

  However, in this system, the collision force of the jet flow can be averaged to some extent by providing a wrap region and eliminating the break in the injection pattern.However, the collision force is reduced in the wrap region compared to the non-wrap region, and the remaining scale is reduced. appear. That is, in the lap region, although the flow rate increases due to the collision of water flows from different directions, the collision force against the steel plate decreases because the water pressure is offset.

  Furthermore, in order to eliminate such scale residue in the lap region, Japanese Patent Application Laid-Open No. 2006-247714 (Patent Document 2) discloses a plurality of elements arranged in a descaling header provided in the width direction of the hot rolled material. In a hot-rolled material descaling method performed by injecting high-pressure water from a single descaling nozzle, the flow rate at one end in the width direction of the spray region of the descaling nozzle is greater than the flow rate at the center in the width direction. There has been proposed a descaling method for a hot rolled material that is large and has a distribution in which the flow rate at the other widthwise end is smaller than the flow rate at the widthwise center. Furthermore, this document describes processing a slit in the tip portion of the nozzle in order to inject with the flow rate distribution.

  However, this document does not describe the details of the shape of the slit in the nozzle tip portion and the specific structure. In addition, while the impact pressure is dominant in the descaling capability, this document describes a descaling nozzle having a flow rate distribution in the width direction, but the flow rate and the impact pressure are not necessarily correlated. Does not have.

JP-A-5-261426 (Claim 1, FIG. 3) JP 2006-247714 A (Claim 1, paragraph [0016])

  Accordingly, an object of the present invention is to provide a flat spray nozzle and a carbide nozzle tip capable of imparting anisotropy to the collision force in the width direction of the discharge flow from the nozzle.

  Another object of the present invention is to provide a descaling nozzle and a carbide nozzle tip that can suppress wrap breakage in overlapping injection regions (wrap regions) between adjacent nozzles and can efficiently remove scale.

  Still another object of the present invention is to provide a descaling nozzle and a carbide nozzle tip that can efficiently remove scale even at low pressure and / or low flow rate.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have determined that when the shape of the discharge hole at the tip of the nozzle is formed in a specific anisotropic shape, the distribution of the collision force in the width direction of the discharge flow from the nozzle is obtained. The present invention was completed by finding that it can be tilted appropriately.

  That is, the spray nozzle of the present invention is a flat spray nozzle that discharges water from the nozzle, the shape of the discharge hole at the tip of the nozzle is an anisotropic shape having a major axis and a minor axis, and a minor axis. As a reference, the shape of the discharge hole is asymmetric. In this spray nozzle, the anisotropic shape of the discharge hole may be substantially elliptical, and the ratio of the major axis to the minor axis (major axis / minor axis) may be about 1.2 to 3 times. Further, when the anisotropic shape of the discharge hole is divided into two along the short axis, the areas of the divided areas are different, and the area ratio of the large area part to the small area part (large area part / small area part) is 1.1 to 1. It may be about 5 times. Further, the shape of the small area portion may be a semi-elliptical shape, and the shape of the large area portion may be a curved U shape. By setting the shape of the discharge hole to such a shape, anisotropy can be imparted to the collision force in the width direction of the discharge flow. This spray nozzle is suitable as a descaling nozzle for discharging water from the nozzle to remove the scale on the surface of the steel sheet.

  Furthermore, in the spray nozzle of the present invention, the distribution of the collision force in the width direction of the discharge flow is inclined, and the maximum collision force value may be 20% or more higher than the minimum collision force value. The collision force value at one end portion may be 1.1 times or more and the collision force value at the other end portion may be 0.9 times or less than the collision force value at the center portion of. When the collision force of the discharge flow is distributed in this way, for example, when used as a descaling nozzle, the collision force is canceled even in the wrap region between adjacent nozzles while maintaining a high collision force in each region. This prevents the remaining scale from occurring.

  The discharge hole may be opened in a substantially elliptical shape with a concave surface or a concave portion formed in the nozzle tip. Thus, by forming the discharge hole in the concave surface or the concave portion, it can be easily opened in an asymmetrical substantially elliptical shape.

  Furthermore, the spray nozzle of the present invention is usually provided with a nozzle tip (a cemented carbide nozzle tip) at the tip. Therefore, the present invention also includes a nozzle tip that can be attached to the tip of the nozzle. The nozzle tip includes a concave surface or a concave portion formed at the tip portion, a discharge hole opened by the concave surface or the concave portion, and a conical flow path extending upstream from the discharge hole at a predetermined taper angle θ. The concave surface or the concave portion may include an inclined side wall inclined inward in the radial direction as it goes upstream from the tip portion. By providing the nozzle with such a specific conical flow path, for example, when used as a descaling nozzle, descaling efficiency can be improved even at a low pressure and / or a low flow rate.

  In the present specification, the short axis means an axis at the midpoint of the long axis.

  In the present invention, the shape of the discharge hole at the tip of the nozzle is formed into a specific anisotropic shape having a major axis and a minor axis, so that the distribution of the collision force in the width direction of the ejection flow from the nozzle is appropriately inclined. it can. When used as a descaling nozzle, it is possible to suppress wrap breakage in an overlapping injection region between adjacent nozzles, and in the case of a descaling nozzle, the scale can be efficiently removed. Further, by combining with a specific conical channel, the scale can be efficiently removed even at a low pressure and / or a low flow rate. Moreover, since the erosion efficiency can be improved even at a low flow rate, the temperature drop of the steel sheet can be suppressed.

FIG. 1 is a schematic perspective view showing an example of a descaling nozzle according to an embodiment of a spray nozzle of the present invention. 2 is a schematic sectional view taken along line II-II in FIG. FIG. 3 is a schematic front view of the nozzle tip of FIG. FIG. 4 is a schematic perspective view of the tip of the nozzle tip of FIG. FIG. 5 is a schematic front view of the tip of the nozzle tip of FIG. FIG. 6 is a schematic diagram illustrating an example of how the descaling nozzle is used. FIG. 7 is a graph illustrating the collision force distribution in the width direction of the discharge flow in the first embodiment. FIG. 8 is a graph showing the collision force distribution in the width direction of the discharge flow in Comparative Example 1. FIG. 9 is a photograph showing aluminum lap region erosion characteristics in Example 1. FIG. 10 is a photograph showing aluminum lap region erosion characteristics in Comparative Example 1.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings as necessary.

  1 is a schematic perspective view showing an example of a descaling nozzle according to an embodiment of the spray nozzle of the present invention, FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. 1, and FIG. 3 is a nozzle in FIG. It is a schematic front view of a front-end | tip part. 4 is a schematic perspective view of the tip of the nozzle tip of FIG. 1, and FIG. 5 is a schematic front view of the tip of the nozzle tip of FIG.

  As shown in FIGS. 1 to 5, the descaling nozzle 1 has a cylindrical casing 2 into which water can flow from the upstream side and a cylindrical flow path (or nozzle hole), and the casing is mounted. A cylindrical nozzle case 11 that can be used, and a cemented carbide nozzle tip 12 that is attached to the tip of the nozzle case and ejects a discharge flow from the tip through a flow path (or nozzle hole). In addition, nozzle holes or flow paths are formed in the axial direction on the shaft cores of these members. In this example, the cylindrical casing 2 includes a first casing 2a that can be screwed to the nozzle case 11, and a second casing 2b that can be attached to the casing. The first casing 2a and the second casing 2b are integrated with each other by screwing or the like.

  A plurality of slits (or inlets) 3 extending in the axial direction in order to allow water to flow into the peripheral surface and end surface (flat surface) of the upstream end portion of the second casing 2b while restricting the inflow of impurities. Are formed at predetermined intervals in the circumferential direction to constitute a filter. The flow path in the second casing 2b is provided with a rectification unit (or rectifier or stabilizer) 4 for guiding the water flowing from the filter to the nozzle hole. A plurality of rectifying plates (rectifying blades) 5 extending in the radial direction from the body, and acute cone portions (coaxially formed on the upstream side and the downstream side of the core body, and formed with their tip portions directed in the upstream and downstream directions, respectively ( (Conical portions 6a, 6b whose upstream side or downstream side is tapered). The 2nd casing 2b which comprises a filter and was equipped with the rectification unit can also be called a filter unit or a rectification casing. The rectifying plate 5 of the rectifying unit 4 is in contact with the inner wall of the casing, and the rectifying unit 4 is restricted from moving downstream by fixing means (locking, mounting, welding, fixing, etc.).

  The flow path of the cylindrical casing 2 extends from the upstream end (inlet) of the second casing 2b to the downstream end of the rectification unit 4 and has substantially the same inner diameter as the cylindrical flow path P1. An inclined flow path (annular inclined flow path) P2 that reaches the middle of the first casing 2a from the downstream end of the unit 4 toward the downstream direction and narrows in a tapered shape with a gentle inclination, and a downstream end of the inclined flow path And a cylindrical flow path P3 having substantially the same inner diameter. In this example, the taper angle of the inclined wall (tapered portion) forming the inclined channel (annular inclined channel) P2 is, for example, about 5 to 12 ° (for example, 5 to 10 °, preferably 6 to 9 °). Is formed.

  In the nozzle case 11, a cemented carbide nozzle tip 12 and a bush having substantially the same inner diameter as the downstream end of the first casing 2 a are formed in the nozzle case 11 in the upstream direction. (Or annular side wall) 17 are sequentially mounted, and the nozzle tip 12 is regulated by the latching step portion 13 in the direction of the tip portion. A curved groove 14 having a U-shaped cross section is formed in the radial direction at the tip surface of the nozzle chip 12, and a substantially elliptical discharge hole 15 is opened in the curved concave surface of the curved groove 14. . Note that the bottom surface of the curved groove 14 having a U-shaped cross section may be a curved bottom surface with both ends projecting in the protruding direction (or extending direction or radial direction) with the discharge hole 15 as the lowermost part.

  A nozzle hole extending in the axial direction of the nozzle 1 is formed in a discharge hole (or a jet port) 15 that is opened in a substantially elliptic shape by the curved concave surface 14 and the nozzle tip 12, and is upstream of the axis line from the discharge hole 15. A conical flow path P5 formed by a tapered portion (or conical inclined wall) 16 extending linearly in the direction of the direction, and the bush 17 and an axis line from the upstream end of the tapered portion 16 It is comprised with the cylindrical flow path P4 which continues in an upstream direction with the substantially same internal diameter along a direction. That is, the flow path (nozzle hole) of the nozzle 1 has a discharge hole 15 opened in an elliptical shape with a curved concave surface 14 at the tip, and a taper part (taper side wall, conical side wall or conical inclined wall) 16 from the discharge hole. A tapered flow path (or conical flow path) P5 extending upstream at a predetermined taper angle θ and a cylindrical flow extending from the upstream end of the taper flow path with substantially the same inner diameter by the annular side wall of the bush 17 Path (flow path from the upstream end of the tapered flow path P5 to the upstream end of the rectifying unit 4) P4 to P1. In addition, the flow paths (in this example, the cylindrical flow paths P3 and P4 from the upstream end of the large diameter portion to the downstream end of the gently inclined flow path) extend from the upstream end of the tapered portion 16 with substantially the same inner diameter. The large diameter portion 18 can be obtained.

  In the present specification, the “large-diameter portion” means a flow passage that extends in the upstream direction from the tapered portion that is continuous with the discharge hole, and a flow passage that extends from the upstream end of the tapered portion with substantially the same inner diameter Dc. . Therefore, “large diameter portion” can be used synonymously with “cylindrical channel”. “Substantially the same inner diameter” from the upstream end of the tapered portion means an average inner diameter of the flow path extending at an angle of 0 to 5 ° (for example, 0 to 3 °). Can be prescribed. Here, “taper angle” (or “angle”) means an angle formed by an extension line of an inclined wall (or an inclined side wall) in a cross section of the taper portion (a cross section passing through the central axis of the flow path). However, it does not mean an angle with respect to the horizontal direction. Further, in this specification, the “taper angle” (or “angle”) may be referred to as “inclination angle”. Furthermore, “a flow path extending with substantially the same inner diameter” means a flow path whose ratio (L / Dc) of the flow path length L to the inner diameter Dc of the flow path is 1 or more. Further, even if the inner diameter portion is substantially the same, a portion where the ratio (L / Dc) of the flow path length L to the inner diameter Dc of the flow path is less than 1 (L / Dc <1) is a part of the tapered portion. And Therefore, a nozzle or nozzle tip formed with a cylindrical flow path extending in the upstream direction from the discharge hole with substantially the same inner diameter, and a conical flow path extending in a tapered shape from the cylindrical flow path in the upstream direction, In the nozzle or nozzle tip in which a conical channel extending in a taper shape in the upstream direction from the discharge hole and a cylindrical channel extending in the upstream direction from the conical channel with substantially the same inner diameter are formed, the cylinder When the ratio (L / Dc) of the channel length L to the inner diameter Dc of the cylindrical channel is less than 1 (L / Dc <1), these cylindrical channels constitute a tapered channel. Furthermore, “the ratio of the inner diameter of the large diameter portion to the major diameter of the discharge hole” means “the ratio of the inner diameter of the downstream end of the large diameter portion (or the upstream end of the taper portion) to the major diameter of the discharge hole”.

  The substantially elliptical shape of the discharge hole 15 is an anisotropic shape having a major axis and a minor axis, but the shape of the ejection hole 15 is asymmetric with respect to the minor axis. That is, when the anisotropic shape of the discharge hole 15 is divided into two along the short axis, the area of the divided area (adjacent area) is different, and the shape of the large area part (first discharge area) 15a is a curved U-shape (the corner part is The shape of the small area portion (second discharge area) 15b is a semi-elliptical shape. The ratio (Da / Db) of the major axis Da to the minor axis Db of the substantially elliptical discharge hole 15 is about 1.8 to 2.2 times. The area ratio of the large area part 15a to the small area part 15b (large area part 15a / small area part 15b) is about 1.1 to 1.5 times.

  In this nozzle, since the discharge hole has such a shape, the distribution of the collision force in the width direction of the discharge flow corresponding to the major axis direction of the discharge hole is inclined, and the large area portion 15a of the discharge hole. The maximum collision force value at the end on the side is about 100 to 150% higher than the lowest collision force value at the end on the small area portion 15b side, and the large area is larger than the collision force value at the center in the width direction. The collision force value at the end on the part 15a side is about 1.3 to 1.6 times, and the collision force value at the end on the small area part 15b side is about 0.4 to 0.7 times.

  The curved groove 14 has a U-shaped cross section along the major axis direction of the discharge hole 15 and is formed to be gently curved as a whole. Further, the curved groove 14 has a shape in which both ends are raised in the major axis direction with the discharge hole 15 being the lowest part of the groove, and the large area side of the discharge hole 15a is formed wider than the small area side. Has been. That is, the cross-sectional shape of the groove in the direction perpendicular to the major axis direction of the discharge hole 15 is such that the large area portion side of the discharge hole 15 is formed wider than the small area portion side, and the depth is substantially the same. It is formed with depth. Specifically, regarding the cross-sectional shape of both ends of the curved groove 14b in the major axis direction of the discharge hole 15, the ratio of the width at the end of the curved groove 14a to the end of the curved groove 14b is 1.3 to 1.4 times. Degree. Thus, by adjusting the groove width of the curved groove 14 asymmetrically, the shape of the corresponding discharge hole 15 can be easily processed into an asymmetric shape.

  Furthermore, regarding the relationship between the substantially elliptical discharge hole 15 and the large-diameter portion 18, the large-diameter portion 18 (cylindrical flow paths P3 and P4, or the inclined flow path extending in the downstream direction from the rectifying unit) with respect to the long diameter Da of the discharge hole 15. The ratio (Dc / Da) of the inner diameter Dc of the downstream end of P2 is set to about 3.6 to 7 in order to reduce the size of the nozzle and increase the average diameter of the droplets (or spray droplets). Yes. Further, the inner diameter Dc of the large diameter portion 18 is set to about 11 to 20 mm, and the length L is set to about 60 to 80 mm, and the ratio of the length L of the large diameter portion to the inner diameter Dc of the large diameter portion (L / Dc) is about 4.2 to 6.0. Furthermore, the angle (taper angle) θ of the tapered portion 16 is set to about 45 to 55 ° in order to increase the collision force even at a low pressure and / or a low flow rate.

  In addition, in a suitable place (in this example, the nozzle case) of the nozzle case 11 and the cylindrical casing 2, a flange (not shown) for attaching the nozzle 1 to a conduit (not shown) using an adapter (not shown). Alternatively, a mounting portion such as a flange 19 can be formed. In addition, the nozzle case 11 may be provided with a positioning projection 20 for positioning the conduit in order to improve positioning accuracy and to eject a flat or strip-like discharge flow in a predetermined direction.

  When such a nozzle 1 is used, the shape of the discharge hole 15 is a specific substantially elliptical shape, and anisotropy can be expressed in the distribution of the collision force. In other words, since the collision force in the large area part based on the substantially elliptical short axis can be made larger than the collision force in the small area part, the small area part and the large area part overlap in the wrap region between adjacent nozzles. If the nozzles are arranged in such a manner, it is possible to suppress a decrease in collision force due to interference in the lap region.

  Further, since the taper portion 16 is linearly inclined through the nozzle hole large diameter portion 18 to reach the discharge hole 15, a sharp collision force distribution can be realized, and the discharge hole is made different on the basis of the short axis. It is formed in a substantially elliptical shape with directionality, and the nozzle hole extending from the discharge hole is formed as a specific conical taper part, realizing a collision force distribution with an inclination in the width direction of the discharge flow and suppressing wrap breakage Even if it is small, the erosion ability is high, and the scale can be efficiently removed at low pressure and / or low flow rate. Moreover, since descaling can be performed at a low pressure and / or a low flow rate, descaling performance can be improved while suppressing cooling of the steel sheet. Further, by bringing the nozzle 1 close to the steel plate, the collision force can be further improved and the descaling performance can be improved. Therefore, the nozzle 1 is useful as a descaling nozzle (or flat descaling nozzle) for discharging droplets (or spray liquid) and removing scales on the surface of the steel plate such as hot rolling.

  The shape of the discharge hole of the nozzle is an anisotropic shape having a major axis and a minor axis, but the shape of the ejection hole may be asymmetric with respect to the minor axis, and is limited to the specific substantially elliptical shape. However, from the point that the flow rate at the center part can be secured and light weight can be given to the collision force at the end part, the substantially elliptical shape, especially the anisotropic shape of the discharge hole, is the short axis. When divided into two, the area of the divided area is different, the shape of the small area portion is semi-elliptical, and the shape of the large area portion is preferably a substantially elliptical shape having a curved U shape.

  The area ratio of the first discharge area (large area part) to the second discharge area (small area part) is, for example, 1.1 to 1.5 times, preferably 1.15 to 1.45 times, and more preferably. Is about 1.2 to 1.4 times (especially 1.25 to 1.35 times). The substantially elliptical discharge hole having the area ratio of the divided areas within this range can secure a sufficient collision force even in the non-wrap area while suppressing a decrease in the collision force due to interference in the wrap area.

  In the shape of the discharge hole, the ratio of the major axis Da to the minor axis Db (Da / Db) is 1.2 to 3 times (for example, 1.3 to 2.5 times), preferably 1.5 to 2.5 times. More preferably, it is about 1.6 to 2.4 times (particularly 1.8 to 2.2 times). The major axis Da of the discharge hole may be, for example, about 1.5 to 12 mm, preferably about 2 to 10 mm, and more preferably about 4 to 8 mm. The minor axis Db may be about 1 to 5 mm (preferably 1.5 to 4 mm, more preferably 2 to 3.5 mm).

  In the present invention, since the discharge hole of the nozzle has such a shape, the distribution of the collision force in the width direction of the discharge flow is inclined, and the maximum collision force value (for example, a large area portion of the discharge hole) The collision force value at the end on the side may be 20% or more higher than the lowest collision force value (for example, the collision force value at the end on the small area side of the discharge hole), for example, 30 to 300%. , Preferably 50 to 250%, more preferably 80 to 200% (particularly 100 to 150%).

  Further, the collision force value at one end (for example, the collision force value at the end portion on the large area side of the discharge hole) is 1.1 times or more than the collision force value at the center in the width direction. For example, it is 1.1 to 5 times, preferably 1.2 to 3 times, more preferably 1.35 to 2 times (particularly 1.3 to 1.6 times), and the other end. The collision force value (for example, the collision force value at the end of the discharge hole on the small area side) may be 0.9 times or less, for example, 0.1 to 0.9 times, preferably 0.2. It is about -0.8 times, more preferably about 0.4-0.7 times. In the present invention, since the collision force value has such a distribution, it is possible to maintain a balance between the suppression of the decrease in the collision force in the lap region and the securing of the collision force in the non-wrap region.

  If the discharge hole can be formed in the asymmetrical shape, the concave surface of the nozzle tip is a U-shaped groove (cross-sectional curved surface) or a curved concave surface (opened side is widened and the upstream side is narrowed) However, it may be a curved concave surface such as a bowl-shaped concave surface or a trumpet-shaped concave surface. Furthermore, the concave surface of the nozzle tip portion may be formed by a concave portion having a curved or linearly inclined side wall. Among these concave shapes, a groove having a U-shaped cross section is preferable because the discharge hole can be easily formed into a substantially elliptical shape.

  When the concave surface has a U-shaped cross section, the end on the large area portion side of the discharge hole with respect to the end portion on the small area side of the discharge hole with respect to the cross-sectional shape of both ends of the curved concave surface (groove) in the major axis direction of the discharge hole The width ratio (large area part side / small area part side) in the part is, for example, 1.1 to 2 times, preferably 1.2 to 1.5 times, more preferably about 1.3 to 1.4 times. It is.

  In the nozzle of the present invention, the shape of the nozzle hole including the tapered portion is particularly limited as long as it has a nozzle hole extending from the large diameter portion to the discharge hole through a predetermined tapered portion and can constitute a flat spray nozzle. First, various nozzle holes (for example, the nozzle holes described in Japanese Patent No. 4084295) can be used. For example, as described above, the taper portion is not limited to the taper portion that is linearly inclined at a predetermined angle, but may be a taper portion that is inclined at a plurality of different angles (multi-stage taper portion), The taper part may be curved and inclined.

  The nozzle hole may normally be composed of a discharge hole opened by a concave surface or a concave portion of the tip portion, a tapered portion extending from the discharge hole, and a large diameter portion connected to the tapered portion. In general, an inclined wall is formed between them.

  The angle (taper angle) θ of the tapered portion is not particularly limited, and may be selected from a range of about 20 to 80 °, and is usually, for example, 30 to 80 °, preferably 35 to 75 ° (for example, 35). ~ 60 [deg.]), More preferably 40-70 [deg.], And particularly 40 to 60 [deg.]. When the taper portion is a curved portion, the taper angle θ is defined as the minimum hole portion (discharge hole) located on the discharge side (downstream side) and the starting end portion of the large diameter portion located on the upstream side. Is an angle formed by a line connecting the two. Moreover, when the taper part is comprised by the some taper part, the said taper angle (theta) means the angle of the taper part located in the most discharge side (downstream side) which affects spray characteristics.

  Further, the ratio (Dc / Db) of the inner diameter Dc of the large diameter portion to the short diameter Db of the discharge hole is not particularly limited, and may be about 2 to 10. In order to reduce the size of the nozzle, the ratio (Dc / Db) is 3 or more (particularly 3 or more and less than 7), for example, 3 to 6.9 (for example, 3 to 6), preferably 3.5 to 6 0.9 (for example, 3.5 to 6), more preferably about 4 to 6.5 (for example, 4 to 6), and about 4.5 to 6 (for example, 4.5 to 5.5). May be. The inner diameter Dc of the large diameter portion may be about 8 to 20 mm (for example, 8 to 15 mm, preferably 9 to 15 mm).

  The large-diameter portion is usually formed to have substantially the same inner diameter. However, unless the descaling efficiency is impaired, the large-diameter portion is upstream at an angle of 0 to 5 ° (for example, 0 to 3 °) as long as the inclined portion is not impaired. The inner diameter may be slightly enlarged and inclined in the direction. The taper angle of the inclined flow path (annular inclined flow path) P2 of the cylindrical casing in FIG. 2 is, for example, about 5 ° to 25 ° [preferably 7 to 15 ° (for example, 10 to 15 °)]. It may be formed. The overall length of the large diameter portion (cylindrical large diameter portion or large diameter flow path portion) is not particularly limited, and is, for example, 30 to 300 mm (for example, 50 to 200 mm), preferably 50 to 150 mm (for example, 75). ˜150 mm). Note that the length of the large-diameter portion extending from the upstream end of the tapered portion with substantially the same inner diameter (for example, the length of the flow path extending to the middle of the first casing 2a in the example shown in FIG. 2) is, for example, It may be about 25 to 200 mm (for example, 30 to 150 mm), preferably about 35 to 150 mm (for example, 40 to 125 mm).

  The nozzle of this invention should just be provided with the taper part extended in the upstream direction from the said discharge hole, and the large diameter part extended with the substantially same internal diameter from this taper part, and the said cylindrical casing is not necessarily required. Further, the rectifying unit is not necessarily required upstream of the nozzle, but usually a rectifying means, for example, the stabilizer (or the rectifying unit) is provided. As the casing and stabilizer, for example, the casing and stabilizer described in Japanese Patent No. 4084295 can be used in addition to the casing and stabilizer shown in FIGS. 1 and 2.

  As is clear from the above, this specification is made of cemented carbide, and the shape of the discharge hole opened by the concave surface or the concave portion is an anisotropic shape having a major axis and a minor axis, and a minor axis. Also disclosed is a cemented carbide nozzle tip which is a nozzle tip having an asymmetrical shape of the discharge hole with respect to the core, and which can be mounted on the nozzle tip.

  The nozzle of the present invention is useful for forming a wrap region in an ejection region (discharge region) between adjacent nozzles. The pitch between adjacent nozzles (distance between the center points of adjacent nozzles) is not particularly limited as long as a wrap region can be formed, and depends on the injection pressure, but is, for example, 30 to 200 mm, preferably 50 to 150 mm, and more preferably Is about 60-120 mm (especially 70-100 mm). In the present invention, it is useful when a plurality of nozzles (for example, nozzles of about 2 to 150, usually about 4 to 70) are used in parallel at equal intervals. Multiple stages may be used.

  When a water flow is jetted through the discharge holes having the anisotropic shape, the jet region becomes a linear (oval) region extending in the major axis direction of the discharge hole while having a predetermined erosion thickness angle. . The ratio (the length ratio of the wrap region in the width direction of the injection region) occupied by the wrap region (total of both ends) in such an injection region is, for example, 1 to 60%, preferably 5 to 50%, and more preferably. It may be about 10 to 45% (particularly 10 to 20%). When the wrap region is formed at such a ratio, the collision force of the discharge flow can be suppressed in the wrap region, and a high collision force can be maintained even in the non-wrap region. The length of the injection region in the width direction is, for example, about 40 to 250 mm, preferably about 60 to 200 mm, and more preferably about 70 to 150 mm.

  With such a nozzle, a sharp and non-uniform (inclined) collision force distribution can be realized. That is, with the nozzle of the present invention, in the collision force distribution of the discharge flow, not only does one end in the width direction show a sharp rise, but also the non-uniformity in which the collision force decreases toward the other end in the width direction. Show a good collision force. With such a collision force distribution, one end portion exhibiting a high collision force suppresses a decrease in the collision force in the lap region, and a relatively high collision force can be maintained even in the central region. In this respect, the conventional nozzle that shows a collision force distribution in the shape of a mountain and a uniform collision force distribution, where the collision force at the center in the width direction is strong and the collision force decreases toward the side, is the point of collision force distribution. to differ greatly.

  The angle of each nozzle with respect to the substrate to be treated (steel plate) is such that the angle of attack is, for example, about 0 to 30 °, preferably 3 to 20 °, more preferably about 5 to 15 ° (particularly 8 to 12 °). The twist angle is, for example, about 0 to 20 °, preferably 1 to 10 °, more preferably about 2 to 8 ° (particularly 3 to 7 °). In the present invention, by setting the nozzle at such an angle, it is possible to suppress a decrease in the collision force in the lap region. In the present specification, the angle of attack means the angle of the axis of the nozzle with respect to the line connecting the tip of the nozzle and the steel plate at the minimum distance, and the twist angle means the steel plate with respect to the major axis of the nozzle discharge hole. It means the angle in the direction perpendicular to the direction of travel.

  The spray distance (spray distance) with respect to the steel plate is not particularly limited as long as the wrap region can be formed at the above ratio, and can be appropriately selected from a range of 600 mm or less (for example, about 50 to 500 mm). For efficient descaling, the nozzle is used close to the steel plate. The spray distance may be 300 mm or less, for example, 50 to 200 mm, preferably 70 to 150 mm, and more preferably about 80 to 120 mm.

  The nozzle is also useful for removing scale of a steel plate (eg, silicon content of 0.5 wt% or more, particularly 1 wt% or more) at high pressure and / or high flow rate. In such a method, liquid droplets (or spray liquid) may be discharged or ejected at a high pressure exceeding 30 MPa (for example, about 35 to 80 MPa, preferably about 37 to 60 MPa, more preferably about 40 to 50 MPa). Further, from the discharge hole, a large discharge flow rate (or spray flow rate), for example, a flow rate of 80 liter / minute or more (for example, 80 to 300 liter / minute, preferably 80 to 250 liter / minute, more preferably 80 to 150). A droplet (or spray liquid) may be ejected at a rate of about 1 liter / minute.

  On the other hand, the nozzle of the present invention can greatly improve descaling efficiency even at low pressure and / or low flow rate. Therefore, in a preferable descaling method, liquid droplets (or spray liquid) from the nozzle at a low pressure, for example, a discharge pressure or an injection pressure of about 5 to 30 MPa (preferably 8 to 25 MPa, more preferably 10 to 20 MPa, particularly 12 to 18 MPa). The scale of the steel sheet can be removed by discharging. Therefore, cooling of the steel plate in the descaling process can be suppressed, and hot rolling can be performed smoothly.

  In the nozzle of the present invention, as described above, a water flow can be injected with a high collision force over the entire surface of the steel sheet without causing lap breakage.

  In addition, the nozzle of this invention is not limited to a descaling nozzle, It can utilize for various flat spray nozzles (nozzle sprayed in a fan shape), for example, a nozzle for cooling a slab during continuous casting for iron making, It can be used for a nozzle for cooling steel material after rolling, a nozzle for cleaning a liquid crystal substrate, and the like. Even in these applications, as described above, the cooling water and the cleaning water can collide over the entire surface of the steel plate and the liquid crystal substrate without causing the wrap to break, so that uniform cooling and cleaning are performed in the width direction. be able to.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In addition, the evaluation method of each evaluation item in an Example, a comparative example, and a reference example is as follows.

Example 1 and Comparative Example 1
The descaling nozzle shown in FIG. 2 was used. The nozzle of Example 1 is a nozzle chip discharge hole (asymmetrical elliptical discharge hole with reference to the short axis shown in FIG. 5, major axis 4.67 mm, minor axis 2.24 mm, large area part / small area part) (Area ratio) = 1.16), taper angle θ of taper portion = 50 °, cylindrical flow path (large diameter portion) having an inner diameter of 11 mmφ and a length of 43.4 mm extending to the middle portion of the nozzle case and the first casing An inclined portion inclined channel (length: 36.1 mm) extending from the upstream end of the cylindrical channel (large diameter portion) at a taper angle of 7.5 °, extending from the upstream end of the inclined channel with an inner diameter of 16 mmφ, and Cylindrical flow path in which a stabilizer (the axial length of the blade is 16 mm, the number of blades extending radially from the shaft portion is 8), a plurality of slits formed at the upstream end of the second casing have. The stabilizer includes conical members whose leading ends are directed upstream and downstream, respectively, on the upstream side and the downstream side.

  In the nozzle used in Comparative Example 1, the shape of the discharge hole of the nozzle tip is 4.68 mm in major axis, 2.16 mm in minor axis, large area part / small area part (area ratio) = 1, and minor axis. The nozzle has the same structure as that of the nozzle of the first embodiment except that it has a symmetrical elliptical shape with reference to.

  And, spray spray pressure (discharge pressure) 15MPa, spray distance 101.5mm, nozzle pitch 81mm, angle of attack 10 °, twist angle 5 °, wrap length 20mm, under conditions of aluminum erosion time 180 seconds, The aluminum lap region erosion characteristics were examined for the aluminum plate A1050. In addition, the collision force distribution in the width direction (longitudinal direction) of spraying with a single nozzle was examined using a sensor having an injection pressure of 15 MPa and an injection distance of 101.5 mm and a pressure receiving portion of 6 mm. Graphs of the collision force distribution in the width direction of the discharge flow of Example 1 and Comparative Example 1 are shown in FIGS. 7 and 8, respectively.

  As is clear from FIG. 7, in Example 1, the collision force distribution in the width direction (longitudinal direction) of spraying with a single nozzle is 1200 gf at one end with respect to 1200 gf at the center, and the other end. Showed an inclined type of 800 gf. Furthermore, as for the wrap area erosion characteristics of aluminum, the erosion of the 20 mm wrap area was normal, and no wrap breakage occurred as shown in FIG.

  On the other hand, as is clear from FIG. 8, in Comparative Example 1, the collision force distribution in the width direction (longitudinal direction) of the spray with a single nozzle is 1200gf at one end with respect to 1150gf at the center, The end portion was 1300 gf, indicating a substantially uniform distribution. Furthermore, as for the wrap area erosion characteristics of aluminum, erosion of the 20 mm wrap area was insufficient, and as shown in FIG.

  The present invention can be used for various flat spray nozzles, such as descaling nozzles, nozzles for cooling slabs during continuous casting for steel making, nozzles for cooling steel products after hot rolling, and nozzles for cleaning liquid crystal substrates. . In particular, it is suitable for descaling of the steel sheet surface (descaling of the steel sheet surface in the hot rolling process), and the type of the steel sheet is not particularly limited. For example, the steel sheet may be a high Si steel sheet with a high Si content, but a low Si steel with a low Si content (for example, the Si content is 0.5 wt% or less (0.2 to 0.5 wt%). It can be used effectively for descaling of ordinary steel.

DESCRIPTION OF SYMBOLS 1,21 ... Descaling nozzle 2 ... Cylindrical casing 4 ... Rectification unit 11 ... Nozzle case 12 ... Nozzle tip 14 ... Curve groove 15 ... Discharge hole 16 ... Tapered part (or conical inclined wall)
17 ... Bush (or annular side wall)
18 ... Large-diameter portion P1 ... Cylindrical channel P2 ... Inclined channel P3 ... Cylindrical channel P4 ... Cylindrical channel P5 ... Conical channel 22 ... Discharge flow 23 ... Injection pattern 23a ... Lapping region 24 ... Descaling Header 25 ... Steel plate

Claims (10)

  A flat spray nozzle that discharges water from a nozzle, the shape of the discharge hole at the tip of the nozzle is an anisotropic shape having a major axis and a minor axis, and the shape of the ejection hole is asymmetric with respect to the minor axis Spray nozzle that is in shape.   The spray nozzle according to claim 1, wherein the anisotropic shape of the discharge hole is substantially elliptical, and the ratio of the major axis to the minor axis is 1.2 to 3 times.   The area of the divided area is different when the anisotropic shape of the discharge hole is divided into two along the short axis, and the area ratio of the large area part to the small area part is 1.1 to 1.5 times. spray nozzle.   The spray nozzle according to claim 3, wherein the shape of the small area portion is a semi-elliptical shape, and the shape of the large area portion is a curved U shape.   The spray nozzle according to any one of claims 1 to 4, wherein the spray nozzle is a descaling nozzle for discharging scale from the nozzle to remove scale on the surface of the steel sheet.   The spray nozzle according to any one of claims 1 to 5, wherein the collision force distribution in the width direction of the discharge flow is inclined, and the maximum collision force value is 20% or more higher than the minimum collision force value.   The distribution of the collision force in the width direction of the discharge flow is inclined, the collision force value at one end is 1.1 times or more than the collision force value at the center in the width direction, and the other end The spray nozzle according to claim 1, which has a collision force value of 0.9 times or less.   The spray nozzle according to any one of claims 1 to 7, wherein the discharge hole is opened in a substantially elliptical shape by a concave surface or a concave portion formed in the nozzle tip.   A nozzle tip is attached to the tip, and the nozzle tip is formed in a concave surface or recess formed in the tip, a discharge hole opened in the recess or recess, and an upstream direction from the discharge hole at a predetermined taper angle θ. A conical flow path extending in the direction, and the concave surface or the concave portion includes an inclined side wall that is inclined inward in the radial direction as it goes upstream from the tip portion. Spray nozzle.   The shape of the discharge hole, which is made of cemented carbide and opened by a concave or concave surface, is an anisotropic shape having a major axis and a minor axis, and the shape of the ejection hole is asymmetric with respect to the axis of the minor axis A carbide tip that can be attached to the tip of the nozzle according to any one of claims 1 to 9.