JP2013063369A - Spray nozzle, spray nozzle device and spray method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spray nozzle which can stably and uniformly cool a sheet steel even if the amount of spray greatly changes, and can control cooling speed of a slab or a sheet steel in a wide range.SOLUTION: A cylindrical spray nozzle 1 includes: a liquid flow path 2, enabling circulation of a liquid; a gas flow path 7, enabling circulation of a gas; a mixing room 9 for mixing the liquid with the gas, both of which have joined after passing through these paths; and a spray port 12 for spraying mist generated in the mixing room; wherein the direction of the circulation in the liquid flow path and the direction of the circulation in the gas flow path are opposite. In the spray nozzle, the cylindrical liquid flow path 2 is provided along the central axial line of the nozzle. In this cylindrical liquid flow path 2, a liquid circulation member 5 is disposed, while at the outer periphery of the liquid flow path, the gas flow path 7 separated by a partition wall 8 is disposed. At the gas flow path 7, a gas inlet port 7a which enables the gas circulation may be formed.

Description

  The present invention relates to an injection nozzle useful for injecting or spraying mist by mixing two fluids of liquid and gas, an injection nozzle device having the nozzle, and a method of spraying or injecting mist by the nozzle.

  A method is known in which air and water are respectively introduced into nozzles and the slab is cooled by spraying or spraying mist on the continuously cast slab.

  For example, Japanese Patent Laid-Open No. 9-220495 (Patent Document 1) discloses a fluid ejection nozzle in which an ejection hole for ejecting a fluid mixture of liquid and gas in a state having an ejection angle is formed at the nozzle tip. A fluid ejection nozzle that ejects the fluid in a more effectively dispersed state while maintaining a desired ejection pattern is disclosed. Japanese Patent Application Laid-Open No. 2008-168167 (Patent Document 2) discloses a nozzle having a nozzle body and a plurality of slit-shaped discharge ports formed at the tip of the nozzle body. A two-fluid nozzle that can improve the uniformity of spray distribution in the thickness direction is disclosed.

  However, in these nozzles, the uniformity of the water amount distribution in the spray and the collision force distribution against the slab and the stability of the spray state are not sufficient. Also, since the spray pattern is a flat pattern (rectangular or oval pattern) with a wide spray width, when a plurality of nozzles are arranged at regular intervals, the spray width is wide, so the ratio of the adjacent spray wraps Decreases with respect to the ratio of the non-wrapped portion. Therefore, the cooling mode differs between the non-wrapped portion and the wrapped portion, and uniform cooling in the width direction of the slab is difficult. Furthermore, since a plurality of nozzles are independently attached to the gas piping and liquid piping of the header, the piping system becomes complicated.

  On the other hand, as a nozzle having a simplified structure, Japanese Patent Laying-Open No. 2005-230715 (Patent Document 3) discloses a cleaning nozzle that can increase the ratio of the wrap width by arranging a plurality of nozzles. When this cleaning nozzle is used for cooling, the uniformity in the width direction of the slab is improved as compared with the conventional nozzle.

  However, even with this nozzle, the uniformity in the width direction of the slab is not sufficient, and the spraying thickness is thin, so the cooling ability is low.

  In addition, as a nozzle for uniformly cooling a hot-rolled high-temperature steel sheet with mist, Japanese Patent Application Laid-Open No. 2006-110611 (Patent Document 4) discloses a mist spray nozzle for performing mist cooling downstream of the mist spray nozzle. A cylindrical lower main body having a throat portion, a cylindrical upper main body provided with an air supply port on the upstream side and a water supply port on the circumferential portion to form a mist, and a mist spray between the lower main body and the upper main body Discloses a hot-rolled steel plate mist cooling device provided with swirl vanes provided with spiral through grooves for stabilizing the shape of the steel plate. This document describes that when the spread angle of the spray is less than 5 °, it becomes a rod-like water flow, and when it exceeds 15 °, it becomes a holocone shape. Furthermore, the effect of the swirl vane can be synergistically doubled by decentering one or more supply ports of air or water in one direction with respect to the nozzle central axis so as to be in the same rotational direction as the swirl vane. Is described.

  However, in this nozzle, when swirling and spraying after gas-liquid mixing, the particles on the outer periphery tend to become coarse, and the stability of the mist in the spray is low. Furthermore, since the spray angle is narrow, the number of nozzles arranged in parallel increases.

  On the other hand, as a nozzle used for an oil burner or the like, Japanese Patent Application Laid-Open No. 2002-126585 (Patent Document 5) is provided with a liquid ejecting section that ejects a liquid pumped from a liquid supply passage while swirling the liquid pumped from the liquid supply passage A gas-liquid mixed spray nozzle provided with a gas jetting section for jetting and feeding the gas pumped from the gas supply path to the liquid jetted from the liquid jet port so that the liquid is atomized, There is disclosed a gas-liquid mixed spray nozzle in which the gas ejection part is configured to eject the gas while swirling the gas. In this nozzle, since the gas swirled in the same direction is ejected to the swirled fluid, the diameter of the ejected liquid particles can be further reduced.

  However, this nozzle has low pattern stability. In particular, in the actual line, it is necessary to change the spray amount depending on the process, but even if the spray amount changes, it is difficult to spray stably and uniformly. In addition, the structure of the nozzle is complicated, and the orifice diameter is as small as about 0.5 mm or less due to the nature of the burner nozzle.

JP-A-9-220495 (Claim 1, paragraph [0006]) JP 2008-168167 A (Claim 1, paragraph [0007]) Japanese Patent Laying-Open No. 2005-230715 (Claim 1, FIG. 3) JP 2006-110611 A (Claim 1, paragraphs [0015] [0016]) JP 2002-126585 A (Claim 1, paragraphs [0008] and [0009], drawings)

  Accordingly, an object of the present invention is to provide a jet nozzle capable of stably and uniformly cooling a slab or steel plate even when the spray amount changes greatly, and controlling the cooling rate of the slab or steel plate in a wide range, and the nozzle. It is an object to provide an injection nozzle device and a spraying method using the above.

  Another object of the present invention is to provide an injection nozzle capable of continuously and stably spraying mist even when the spray amount changes greatly, and an injection nozzle device and a spray method using the nozzle.

  Still another object of the present invention is to provide a spray nozzle capable of spraying mist having a uniform water amount distribution and collision force distribution even when a plurality of spray nozzles are sprayed in parallel at equal intervals, and a spray nozzle device using the nozzle, and It is to provide a spraying method.

  Another object of the present invention is to provide a spray nozzle capable of suppressing a decrease in spray uniformity due to a wrap portion even if a plurality of spray nozzles are sprayed in parallel at equal intervals, and a spray nozzle device and a spray method using the nozzle. Is to provide.

  Still another object of the present invention is to provide an injection nozzle device capable of simplifying the structure even when a plurality of injection nozzles are combined.

  As a result of intensive studies on the reason why stable spraying is difficult in the nozzle of Patent Document 5, the present inventor has found that the liquid swirling direction and the gas swirling direction are the same. did. Furthermore, as a result of continuous investigations, the present inventor has conducted a multiplex wrap (a plurality of patterns are overlapped and jetted in parallel with each other) by mixing the liquid and gas that have passed through the liquid flow path and the gas flow path and joined together. In a cylindrical injection nozzle for jetting in a full cone pattern, the swirling direction (or the rotating direction) of the gas flow path and the swirling direction of the liquid flow path are adjusted in opposite directions, Stable and uniform cooling of slabs and steel sheets, etc., even if the spray amount changes greatly. In addition, the cooling rate of slabs and steel sheets, etc. is controlled over a wide range in order to have a large cooling performance at a high spray amount. The present invention has been completed by finding out what can be done.

  That is, the jet nozzle of the present invention includes a liquid flow path capable of swirling liquid, a gas flow path capable of swirling gas, and a mixing chamber for mixing the liquid and the gas that have merged after passing through the flow paths. And a cylindrical injection nozzle having an injection port for injecting the mist generated in the mixing chamber, wherein the swirling direction of the gas flow path and the swirling direction of the liquid flow path are opposite to each other . In the present invention, the mist is continuously sprayed with a stable spray amount because the swirl direction of the gas flow path and the swirl direction of the liquid flow path are reversed so that the liquid and the gas are sufficiently mixed. it can.

  The spray nozzle of the present invention is provided with a cylindrical liquid flow path along the nozzle center axis, and a liquid swirling member is disposed in the liquid flow path, and a gas is provided around the liquid flow path with a partition wall therebetween. A flow path may be provided, and a gas inlet capable of turning the gas may be formed in the gas flow path. By disposing the liquid flow path and the gas flow path in a double tubular shape in this manner, the swirled gas can be efficiently applied to the swirled liquid in the mixing chamber.

  The liquid swirling member includes a columnar member and a plurality of spiral flows formed at equal intervals in the circumferential direction of the columnar member and spirally inclined at a predetermined angle with respect to the axial direction of the columnar member. It may be formed with a road. Further, in the nozzle axis direction, the length of the liquid swirl member may be about 1.5 to 8 times the length of the mixing chamber. By setting the liquid swirling member to such a structure, the liquid can be swirled stably with a simple structure.

  In the gas flow path capable of swirling gas, a plurality of gas inlets are formed on the side surfaces of the gas flow path, and the flow paths of the respective gas inlets are directed to the central axis of the nozzle in a cross section perpendicular to the nozzle axis direction. The direction may be inclined by a predetermined angle in the same direction as the spiral direction of the spiral flow path in the liquid swirling member. By forming such a gas inlet, the gas can be swirled stably with a simple structure.

  In the injection nozzle of the present invention, a conical channel having a concentrically increasing diameter in the downstream direction is formed on the downstream side of the mixing chamber, and the shape of the injection port located at the tip of the conical channel is substantially the same. It may be circular. By having such an injection port shape and a conical channel, a full cone pattern mist can be injected.

  In the spray nozzle of the present invention, a throat portion may be interposed between the mixing chamber and the conical channel. By interposing the throat portion, uniform mist can be injected by narrowing down the mist generated in the mixing chamber.

  In the spray nozzle of the present invention, an orifice portion having a diameter narrower than that of the liquid channel may be formed on the upstream side of the liquid swirl member. By forming the orifice portion, the supply amount of the liquid can be stabilized. The flow path diameter of the orifice part may be 1 mm or more, and since the orifice part has such a flow path diameter, mist can be smoothly injected.

  In the spray nozzle of the present invention, the gas is usually air and the liquid is water.

  The present invention also includes a method of injecting mist using the injection nozzle. When the spray nozzle of the present invention is used, it is possible to spray mist having a uniform water amount distribution. The method of the present invention may be a method of injecting a full cone pattern mist. Mist of full cone pattern can be sprayed mist stably and continuously when it is juxtaposed with small pitch multiple laps (with the pitch interval between adjacent full cone patterns being reduced and the overlap part being enlarged). It is possible to suppress a decrease in the uniformity of spraying.

  In the present invention, a long cylindrical first header for supplying liquid, a long cylindrical second header for supplying gas, and an interval in the longitudinal direction of these headers are provided. A plurality of spray nozzles attached through the headers, wherein the plurality of spray nozzles are the spray nozzles, and the liquid flow path of the spray nozzles is in the first header. And an injection nozzle device having a gas flow path leading into the second header. This spray nozzle device has a simple structure despite a combination of a plurality of nozzles. In the nozzle device of the present invention, the injection nozzles may be attached to the header at regular intervals with a pitch of 40 to 120 mm. Further, the present invention includes a method of cooling a slab or a steel plate by injecting a full cone pattern mist that spreads at an angle of 15 to 90 ° from each injection nozzle of the injection nozzle device. By attaching the spray nozzles at the pitch and spraying the full cone pattern mist, even if a plurality of spray nozzles are sprayed in parallel at equal intervals, a mist with a uniform water volume distribution and collision force distribution can be sprayed. Decrease in spray uniformity due to the portion can be suppressed. In the present invention, by appropriately controlling the number of nozzles and the spray pattern of the nozzles, it is possible to suppress a decrease in spray uniformity due to the wrap portion, and to stably eject uniform mist.

  In the present specification, the “taper angle” (or “angle”) is formed by an extended 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). It means an angle, not an angle with respect to the horizontal direction.

  In the present invention, in a cylindrical injection nozzle for injecting a mist that is a mixture of a liquid and a gas that have passed through a liquid channel and a gas channel, the swirling direction of the gas channel and the liquid channel Since the swirl direction is opposite, the slab and steel plate can be cooled stably and uniformly even when the spray amount changes greatly (with wide turndown), and the cooling rate of the steel plate can be controlled over a wide range. it can. In particular, slabs and steel sheets can be uniformly cooled even with a spray amount of about 1/20 times the spray amount used (town down of 1/20). That is, the spray nozzle of the present invention can be sprayed stably and continuously. Therefore, even if a plurality of spray nozzles are sprayed in parallel at equal intervals, mist having a uniform water amount distribution and collision force distribution can be sprayed. Moreover, even if a plurality of spray nozzles are sprayed in parallel at equal intervals, it is possible to suppress a decrease in spray uniformity due to the wrap portion. Furthermore, the structure is simple despite the combination of a plurality of injection nozzles. The spray nozzle of the present invention having such characteristics is suitable for cooling steel plates and cast slabs because uniform cooling is possible.

FIG. 1 is a schematic cross-sectional view showing an example of the injection nozzle of the present invention. FIG. 2 is a schematic sectional view taken along line AA of the injection nozzle of FIG. FIG. 3 is a schematic perspective view of a liquid swirl member constituting the injection nozzle of FIG. FIG. 4 is a schematic perspective view showing a state where mist is jetted using an example of the jet nozzle apparatus of the present invention. FIG. 5 is a schematic diagram comparing the spray patterns of Example 1 and Comparative Examples 1-2.

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

[Injection nozzle]
The jet nozzle of the present invention includes a liquid flow path capable of swirling liquid, a gas flow path capable of swirling gas, a mixing chamber for mixing the liquid and the gas that have passed through each of the flow paths, A cylindrical injection nozzle having an injection port for injecting mist generated in the mixing chamber, wherein the swirl direction of the gas flow path and the swirl direction of the liquid flow path are opposite to each other. In the present invention, the liquid and gas are sufficiently mixed in the mixing chamber by adjusting the swirl direction with the liquid flow path and the swirl direction with the gas flow path in the opposite direction, or the mist with a stable spray amount. The structure of the gas channel and the liquid channel is not particularly limited. In general, an injection nozzle has a cylindrical inner flow path, and has a simple structure and can spray a stable mist. Therefore, a cylindrical liquid flow path is provided along the nozzle central axis, and the liquid flow path is provided. A structure in which a liquid swirling member is provided, a gas flow path is provided on the outer periphery of the liquid flow path with a partition wall therebetween, and a gas inlet is formed in a direction in which the gas can swirl is preferable.

  1 is a schematic cross-sectional view showing an example of the injection nozzle of the present invention, FIG. 2 is a schematic cross-sectional view taken along line AA of the injection nozzle of FIG. 1, and FIG. 3 is a liquid swirl constituting the injection nozzle of FIG. It is a schematic perspective view of a member.

  This injection nozzle 1 has, as a main structure, a liquid channel for supplying liquid from the first cylindrical channel 2 to the third cylindrical channel 6, and a downstream portion of the liquid channel. A gas flow path 7 (annular flow path) for supplying gas formed independently of the liquid flow path with a partition wall 8 on the outer periphery, and the liquid flow path and the gas flow path 7 in opposite directions, respectively. Are provided with a mixing chamber 9 for mixing and mixing the liquid and gas that are swirled and supplied, and an injection port 12 for injecting the mist generated in the mixing chamber 9.

  Specifically, in the liquid flow path, two cylindrical liquid inlets 2a facing each other are formed on the side of the first cylindrical flow path 2 at the upstream portion of the first cylindrical flow path 2. Thus, liquid can flow in from the liquid inlet 2a in a direction perpendicular to the axis of the nozzle. The diameter of the liquid inlet 2 a is formed with a narrower width than the diameter of the first cylindrical channel 2. The diameter of the liquid inlet 2 a is about 0.4 to 0.9 times the channel diameter of the first cylindrical channel 2.

  In the liquid channel, a cylindrical orifice portion 3 having a channel width narrower than that of the first cylindrical channel (large-diameter cylindrical channel) 2 is formed on the downstream side of the liquid inlet 2a. Has been. By passing the liquid through the orifice portion 3, the flow rate of the liquid supplied from the liquid inlet 2a to the liquid flow path 2 can be made constant. The flow path diameter of the orifice portion 3 is about 0.1 to 0.3 times the flow path diameter of the liquid flow path 2.

  The first cylindrical flow channel 2 and a second cylindrical flow channel (large-diameter cylindrical flow channel) 4 having the same diameter as the flow channel communicate with each other through the orifice portion 3. A liquid swirling member 5 for further swirling the liquid is disposed downstream of the second cylindrical flow path 4. The liquid revolving member 5 is formed in a spiral shape at an angle of about 30 to 60 degrees with respect to the columnar member 5a and the circumferential direction of the columnar member 5a and at an equal interval with respect to the axial direction of the columnar member 5a. And four spiral channels 5b that are inclined and have a substantially U-shaped cross section. That is, in the liquid turning member 5, since the four flow paths 5b are formed in a spiral shape in the same direction, the liquid that has passed through the spiral flow path is in a certain direction (clockwise direction in FIG. 2). Turn. The spiral channel 5b has a channel diameter (average of the long side and the short side) of about 0.1 to 0.3 times the channel diameter of the second cylindrical channel 4.

  In the injection nozzle 1, the length of the liquid swirling member 5 in the nozzle axial direction is about 1.5 to 8 times the length of the mixing chamber 9 (L in FIG. 1). Therefore, the liquid can be sufficiently swirled and supplied to the mixing chamber.

  Via the liquid swirl member 5, the second cylindrical flow path 4 and a third cylindrical flow path (long cylindrical flow path) 6 having the same diameter as the flow path communicate with each other. The cylindrical flow path 6 communicates with the mixing chamber 9.

  On the other hand, the gas flow path 7 is formed independently of the liquid flow path with a partition wall 8 around the outer periphery of the liquid turning member 5 and the third cylindrical flow path 6. Furthermore, the gas flow path 7 is provided with two gas inlets 7a in the inner wall which opposes the upstream part, and each gas inlet 7a is eccentric from the central axis, and is an annular gas flow path. The gas can flow in from a substantially tangential direction so as to follow the outer wall of the nozzle 7, and more specifically, in each of the cross sections perpendicular to the nozzle axis direction, the spiral in the liquid swiveling member 5 with respect to the direction toward the central axis of the nozzle It is inclined at an angle of 50 to 70 ° (θ in FIG. 2) in the same direction as the spiral direction of the channel 5b. Therefore, gas can flow in the circumferential direction along the inner wall of the gas flow path 7 from each gas inlet 7a, and the gas that has passed through the gas flow path is in a certain direction (counterclockwise direction in FIG. 2). ). In the present invention, in order to adjust the swirling direction of the gas in the gas flow path 7 in the direction opposite to the swirling direction of the liquid in the liquid flow path, the combined gas and liquid are mixed in the subsequent mixing chamber 9. Thoroughly mixed and stable spraying is possible. The thickness of the annular gas channel 7 is about 0.05 to 0.2 times the channel diameter of the first to third cylindrical channels of the liquid channel. Furthermore, the flow path diameter of the gas inlet 7 a is substantially the same as the thickness of the annular gas flow path 7.

  The third cylindrical channel 6 and the gas channel 7 both communicate with the mixing chamber 9, and the gas and liquid swirling in the opposite directions independently from each other merge in the mixing chamber 9. The mixing chamber 9 is formed in a conical shape whose diameter decreases concentrically in the downstream direction. Therefore, along the conical wall surface, the liquid and the gas supplied from the liquid channel and the gas channel are supplied while smoothly turning, and the liquid and the gas are sufficiently turned by turning in the opposite directions. And a stable mist is prepared. The taper angle of the inclined wall (tapered portion) forming the conical channel of the mixing chamber 9 is formed to be about 90 to 120 °.

  A cylindrical throat portion 10 is formed on the downstream side of the mixing chamber 9. The mist generated in the mixing chamber 9 is squeezed by passing through the throat portion 10 and can be injected with a constant spray amount. The channel diameter of the throat portion 10 is about 0.1 to 0.3 times the first to third cylindrical channel diameters of the liquid channel. The flow path length of the throat portion 10 is about 0.1 to 1.5 times the length of the mixing chamber 9 in the nozzle axis direction.

  A conical channel (spray pattern forming portion) 11 whose diameter increases concentrically in the downstream direction is formed on the downstream side of the throat portion 10, and a substantially circular injection port 12 is formed at the nozzle tip. It is open. The mist that has passed through the throat portion 10 is released by passing through the spray pattern forming portion 11 and expands in a conical shape. The length of the spray pattern forming portion 11 in the nozzle axis direction is about 3 to 10 times the flow path length of the throat portion 10. The taper angle of the inclined wall (taper portion) forming the conical flow path of the spray pattern portion 11 is formed to be about 15 to 90 °. Since the length and the taper angle of the spray pattern forming portion are within this range, the mist expanded in a conical shape can stably spray the mist of the full cone pattern while the water amount distribution is kept uniformly.

  Note that, as described above, the injection nozzle of the present invention only needs to exhibit the above effect by adjusting the swirling direction of the liquid and the gas in the reverse direction, and the nozzle structure for adjusting the swirling direction is the above drawing. It is not limited to the structure.

  In the injection nozzle having such a structure, the shape of the liquid channel is not limited to a cylindrical shape, and may be an elliptical column shape, a prism shape, a conical shape or a pyramid shape in which the flow channel narrows in the downstream direction. .

  The number of liquid inlets is not limited to two and can be selected from about 1 to 6, but 2 to 4 (especially 2) is preferable from the viewpoint that liquid can be stably supplied to the liquid flow path. In the case of forming a plurality of liquid inlets, it is preferable to form the liquid inlets at symmetrical positions in the cross section of the liquid channel from the viewpoint that the liquid can be stably supplied to the liquid channel. The shape of the liquid inlet is not limited to a cylindrical shape, and may be, for example, an elliptical column shape or a prismatic shape. The diameter of the liquid inflow port is not limited to a width narrower than the diameter of the large cylindrical flow path, and may be a wide width. A width narrower than the channel diameter of the channel is preferable, for example, 0.1 to 1 times, preferably 0.2 to 0.9 times, and more preferably about 0.4 to 0.9 times.

  The shape of the orifice portion is not limited to a cylindrical shape, and may be an elliptical column shape, a rectangular column shape, or the like, but it is a cylinder from the viewpoint of stably supplying liquid to the liquid swirling member and easily spraying full cone pattern mist. The shape is preferred. The flow path diameter of the orifice part may be narrower than the flow path diameter of the large cylindrical flow path (minimum flow path diameter when having different flow path diameters), for example, 0.05 to 0.8 times, preferably It is about 0.08 to 0.5 times, more preferably about 0.1 to 0.3 times. Although depending on the size of the nozzle, the flow path diameter of the orifice part may be, for example, about 0.5 to 6 mm, preferably about 1 to 5 mm, and more preferably about 2 to 4 mm. In particular, the flow path diameter of the orifice portion is particularly preferably 1 mm or more (for example, 1 to 4 mm) from the viewpoint that mist can be smoothly injected without clogging.

  The liquid swirl member may be formed on the downstream side of the orifice portion and can swirl the liquid. However, a cylindrical member having a spiral flow path is preferable from the viewpoint that the liquid can be swirled easily.

  In this liquid swirling member, the number of spiral flow paths penetrating in the substantially axial direction of the nozzle is not particularly limited, and can be selected from a range of about 1 to 10, but the liquid swirled stably into the mixing chamber can be selected. From the point which can supply, multiple, for example, 2-8 pieces, Preferably 3-6 pieces, More preferably, about 3-4 pieces are preferable. The cross-sectional shape of the spiral channel is not particularly limited, and may be, for example, a substantially square shape, a substantially semicircular shape, a substantially U shape, or the like, in addition to a substantially U shape (or a substantially rectangular shape). The spiral flow path only needs to be formed in a spiral shape by tilting in the axial direction of the cylindrical member in order to swirl the liquid, and the tilt angle with respect to the axial direction can be selected according to the arrangement of the nozzles, If the distance is short, it may be adjusted to a wide angle, while if it is long, it may be adjusted to a narrow angle. The specific inclination angle may be, for example, about 10 to 80 °, preferably 20 to 70 °, more preferably about 30 to 60 ° (particularly 40 to 60 °) from the viewpoint that the liquid can be swirled stably. Good. The channel diameter of the spiral channel (in the case of an anisotropic shape, the average of the long side and the short side) depends on the number of spiral channels, but for example, with respect to the channel diameter of the liquid channel, for example, It is 0.1 to 0.5 times, preferably 0.1 to 0.4 times, and more preferably about 0.1 to 0.3 times.

  The length in the nozzle axis direction of the liquid swirl member may be shorter than the length in the nozzle axis direction of the mixing chamber, but is longer than the length of the mixing chamber in that the liquid can be sufficiently swirled and supplied to the mixing chamber. For example, 1.1 to 12 times, preferably 1.2 to 10 times, more preferably 1.5 to 8 times (particularly 2 to 6 times) the length of the mixing chamber. Also good.

  Although the thickness of the annular gas channel depends on the channel diameter of the liquid swirl member, the thickness of the annular gas channel is, for example, 0.01 to 0 with respect to the channel diameter of the liquid channel because it can be effectively mixed with the liquid in the mixing chamber. 0.5 times, preferably 0.03 to 0.3 times, more preferably 0.05 to 0.2 times (particularly 0.06 to 0.15 times).

  The number of gas inlets is not limited to two, and can be selected from about 1 to 6, but is preferably about 2 to 4 because gas can be stably supplied to the gas flow path. When a plurality of gas inlets are formed, they are formed at symmetrical positions in a cross section perpendicular to the nozzle axis direction from the point that gas can be stably supplied to the gas flow path (disposed at equal positions in the circumferential direction). Are preferred).

  The gas inlet only needs to be eccentric from the central axis so as to flow along the outer wall of the gas flow path in order to swirl the gas in the gas flow path. Therefore, it is necessary to incline in the same direction as the spiral direction of the spiral flow path in the liquid swirling member with respect to the direction toward the central axis of the nozzle. That is, the gas inlet is, for example, an angle of 10 to 90 °, preferably 30 to 90 °, more preferably 40 to 90 ° (particularly 50 to 90 °) with respect to the direction toward the axis of the nozzle (see FIG. 2 may be formed at an inclination of θ. Inclining the gas inlet by 90 ° means that the gas inlet is formed in the tangential direction of the inner peripheral wall of the annular gas flow. The larger the inclination angle, the easier the gas is swirled. The pressure can be appropriately selected according to the pressure of the liquid. When a plurality of gas inlets are formed, each gas inlet only needs to be inclined in the same direction as the spiral direction of the spiral flow path, and the inclination angle may be different, but usually the same It is.

  The shape of the gas inlet is not limited to a cylindrical shape, and may be, for example, an elliptical column shape or a prismatic shape. The diameter of the gas inlet is not limited to the same thickness as the annular gas channel, and may be different from the thickness of the gas channel, but the cross-sectional area of the gas channel is larger than the cross-sectional area of the gas inlet. For example, 0.3 to 3 times, preferably 0.5 to 2 times, and more preferably 0.8 to 1.5 from the point that gas can be effectively swirled in the annular gas flow path because it needs to be large. Double (especially approximately the same thickness) is preferred. Although depending on the size of the nozzle, the diameter of the gas inlet may be, for example, 0.3 to 3 mm, preferably 0.5 to 2 mm, and more preferably about 0.8 to 1.5 mm.

  The shape of the mixing chamber is not limited to a conical shape whose diameter decreases toward the downstream direction, but is a pyramid shape, a cannonball shape, or a bowl shape whose diameter decreases toward the downstream direction (a curved surface shape in which a conical inclined wall extends outward). Or a shape that is R-shaped), a cylindrical shape, an elliptical columnar shape, a prismatic shape, or the like. The shape is preferred. When the mixing chamber forms a conical channel, the taper angle of the inclined wall is, for example, about 30 to 150 °, preferably about 50 to 140 °, and more preferably about 60 to 130 °.

  The throat part is formed in order to stably spray the mist generated in the mixing chamber, and the channel diameter of the throat part is 0.05 to 0.5 times the channel diameter of the liquid channel, preferably 0. 0.08 to 0.4 times, more preferably about 0.1 to 0.3 times. Although depending on the size of the nozzle, the flow path diameter of the throat portion may be, for example, 0.5 to 6 mm, preferably 1 to 5 mm, and more preferably about 1.5 to 4 mm. The flow path length of the throat portion is, for example, 0.1 to 3 times, preferably 0.1 to 2 times, more preferably 0.1 to 1.5 times the length of the mixing chamber in the nozzle axis direction. Degree.

  The shape of the spray pattern forming portion (conical channel) can be selected according to the shape of the spray pattern, and when spraying a full cone pattern mist, it is a conical shape whose diameter concentrically expands in the downstream direction. The length of the spray pattern forming part in the nozzle axis direction can be selected from a range of about 0.1 to 50 times the flow path length of the throat part, but from the point that mist with a uniform water amount distribution can be sprayed, for example 1 to 30 times, preferably 2 to 20 times, more preferably about 3 to 10 times. When the spray pattern forming part is conical, the taper angle of the inclined wall can be selected from the range of about 5 to 40 °, but the mist of the full cone pattern can be stably sprayed while keeping the water amount distribution uniform. Therefore, it is, for example, about 5 to 120 °, preferably about 10 to 105 °, and more preferably about 15 to 90 °.

  The spray nozzle of the present invention can continuously spray a mist having a uniform water amount distribution and a collision portion distribution with a stable spray amount, and the type of gas and liquid is not particularly limited. And pressurized air is used as the gas.

  In the jet nozzle of the present invention, the flow rate of the liquid supplied to the liquid channel is, for example, 1 to 300 liters / minute · m, preferably 1.5 to 200 liters / minute · m, and more preferably 2 to 100 liters / minute. Min.m (particularly 3-60 liters / min.m). If the flow rate of the liquid is too low, the cooling capacity is low when used as a cooling nozzle, and if the flow rate is too high, the uniformity of the water amount distribution and the collision force distribution decreases.

The amount of gas to be supplied to the gas flow path can be selected according to the structure of the nozzle. For example, 1 to 300 m ³ / h · m (N), preferably ³ to 200 m ³ / h · m, more preferably It is about 5-100 m < ³ > / h * m (especially 10-50 m < ³ > / h * m).

  The volume ratio of gas to liquid is, for example, gas / liquid = 1/1 to 500/1, preferably 2/1 to 400/1, more preferably 3/1 to 300/1 (particularly 4/1 to 250). / 1) grade.

  The pressure of the liquid supplied to the liquid channel is, for example, about 0.01 to 2 MPa, preferably about 0.02 to 1.5 MPa, and more preferably about 0.03 to 1 MPa.

  The pressure of the gas supplied to the gas channel is, for example, about 0.01 to 1.5 MPa, preferably about 0.02 to 1 MPa, and more preferably about 0.03 to 0.7 MPa.

[Injection nozzle device]
The injection nozzle device of the present invention includes a long cylindrical first header for supplying liquid, a long cylindrical second header for supplying gas, and a distance in the longitudinal direction of these headers. And a plurality of injection nozzles attached through these headers, wherein the plurality of injection nozzles are the injection nozzles, and the liquid flow path of the injection nozzles is the first. And the gas flow path communicates with the second header.

  FIG. 4 is a schematic perspective view showing a state in which mist is jetted using an example of the jet nozzle apparatus of the present invention.

  This injection nozzle device is composed of a long hollow cylinder having a rectangular cross section, and is substantially parallel to the first header (or liquid header) 21 for supplying a liquid and the first header. A second header (gas header) 22 that is disposed and is formed of a long and rectangular hollow cylinder and supplies gas, and at almost equal intervals in the longitudinal direction of these headers 21 and 22. In addition, a mounting port (or a through-hole, not shown) formed in a direction orthogonal to the longitudinal direction of the first and second headers 21 and 22 can be inserted through each mounting port. It is comprised with the injection nozzle 23 of the hollow cylinder shape. The liquid inlet of the liquid channel is located in the first header 21, the liquid channel is in communication with the first header 21, and the gas inlet of the gas channel is the second header Located within 22, the liquid flow path leads into the second header 22. Furthermore, the flow path of the liquid inlet and the gas inlet is formed in a direction perpendicular to the longitudinal direction of the header (not shown). In addition, a liquid supply pipe and a gas supply pipe are connected to both side surfaces of the first header 21 and the second header 22 in the longitudinal direction as means for supplying a liquid or a gas, respectively (not shown). ), The supply direction of the liquid and gas is not particularly limited, and the liquid and gas may be supplied in parallel with the mist injection direction, and the liquid and gas are supplied along the longitudinal direction of the header from both side surfaces of the header in the longitudinal direction. You may supply. In addition, the mounting ports (through ports) of the headers 21 and 22 are formed so as to penetrate the opposing surfaces of the headers 21 and 22 having a square cross section. Further, each injection nozzle 23 is attached so as to penetrate the header so that the injection port is located at the lower part of the header, and the nozzle end protruding from the upper part of the header is fixed by a nut 24. Since this injection nozzle device has a plurality of injection nozzles integrated through the header, the structure is simple despite the combination of a plurality of nozzles.

  Such an injection nozzle device is suitable as a cooling nozzle for slabs or steel plates. That is, as shown in FIG. 4, when cooling continuously cast slabs or hot-rolled steel plates, industrially produced slabs or steel plates are wide, so one slab or steel plate On the other hand, the slab and the steel plate are cooled by using a plurality of injection nozzles arranged in parallel at a predetermined interval on the header. Specifically, the full cone pattern mist 15 is sprayed from each spray nozzle toward the slab or steel plate so as to be substantially perpendicular to the surface of the slab or steel plate (not shown). To be cooled.

  In the spray nozzle device of the present invention, the header structure and the mounting method of the spray nozzle to the header can use a conventional header and mounting method. For example, the header and mounting method described in JP-A-2005-230715 Etc. can be used.

  In the spray nozzle device of the present invention, the pitch of the spray nozzles attached to the header in parallel at equal intervals is important. That is, the mist sprayed from each nozzle device is sprayed so as to overlap in order to cool the slab and the like uniformly, but sprays a mist with a uniform water amount distribution and collision force distribution, and a lap portion. The pitch of each nozzle is, for example, about 20 to 150 mm, preferably about 30 to 140 mm, and more preferably about 40 to 120 mm (particularly 50 to 100 mm) from the viewpoint of suppressing a reduction in spray uniformity due to. The pitch of each nozzle may be about 0.1 to 2 times (particularly 0.2 to 1 time) with respect to the ejection distance.

  Furthermore, in the present invention, when the full cone pattern mist is sprayed from the spray nozzles attached to the header at the pitch, the spray angle of the full cone pattern is, for example, 5 to 120 °, preferably 10 to 105 °, Preferably, you may adjust to about 15-90 degrees. When a full cone pattern mist is ejected at such an ejection angle from a nozzle device having injection nozzles attached at the pitch, the full cone patterns are arranged in parallel at a small pitch, and the overlap between adjacent full cone patterns becomes large. Therefore, in the width direction, mist having a uniform water amount distribution and a collision force distribution can be continuously and stably injected, and uniform and high cooling is possible.

  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 and a comparative example is as follows.

[Heat transfer coefficient and cooling uniformity ratio in the width direction]
In the cooling process of a stainless steel plate (SUS304 plate, length 300 mm × width 450 mm × thickness 30 mm) heated to 1050 ° C., cooling is started when the temperature of the steel plate reaches about 1000 ° C., and the cooling capacity at 950 ° C. and its equivalent The rate was determined using a K thermocouple. The K thermocouple is inserted in the thickness direction of the steel plate from the non-cooled surface of the steel plate (the surface opposite to the surface on which the mixed mist is sprayed), and the position of the K thermocouple is 2 mm deep from the cooling surface. It was embedded and fixed as is. Furthermore, the average value of the heat transfer coefficient (HTC) in the thickness direction of each nozzle was calculated at regular intervals in the width direction, and the minimum value when the maximum value was 100% was defined as the uniformity ratio.

Comparative Example 1
Using the injection nozzle described in Example 1 of Japanese Patent Application Laid-Open No. 2008-168167, mist was sprayed on the stainless steel plate under the conditions described in Table 1, and the heat transfer coefficient and the width-direction uniformity ratio were measured.

Comparative Example 2
Using a spray nozzle described in Example 1 of Japanese Patent Laid-Open No. 2005-230715, mist was sprayed on a stainless steel plate under the conditions described in Table 1, and the heat transfer coefficient and the uniformity in the width direction were measured.

Example 1
Using the injection nozzle shown in FIG. 1 (orifice portion diameter 2 mm, gas inlet diameter 1 mm, throat portion diameter 2.5 mm, spray pattern forming portion taper angle 40 °) under the conditions described in Table 1, Mist was sprayed on the stainless steel plate, and the heat transfer coefficient and the uniformity in the width direction were measured.

  The results are shown in Table 1. In addition, the schematic schematic diagram which compared the spray pattern of Comparative Examples 1-2 and Example 1 is shown in FIG. As is clear from FIG. 5, with respect to the steel plate 30, the comparative example 1 is a flat pattern 32 with a large pitch and a small lap, and the comparative example 2 is a flat pattern 32 with a small pitch multiple lap, The first embodiment is a full cone pattern 33 of a small pitch multiple lap. Moreover, in the flat pattern 31 of the comparative example 1, the ratio of a lap | wrap part is few with respect to a non-wrap part, and the cooling uniform rate is low. In the flat pattern 32 of the comparative example 2, since the ratio of the wrap portion is large, the cooling uniformity ratio is improved, but it cannot be said that it is sufficient, and the spray thickness is thin, and the cooling ability is lowered. On the other hand, in the full cone pattern 33 of Example 1, since the ratio of the lap portion is large, the spray pattern is uniform and stable, and the spray thickness is large, the cooling uniformity rate is high, and the large High cooling capacity at flow rate.

  As is clear from the results in Table 1, the injection nozzles of the examples have a higher cooling uniformity ratio in the width direction than the injection nozzles of the comparative example. Furthermore, since the cooling performance is high at the maximum water amount, the cooling rate of the steel sheet can be controlled in a wide range.

Comparative Example 3
The mist was sprayed on the stainless steel plate in the same manner as in Example 1 except that the gas swirl direction and the liquid swirl direction were the same direction, using the spray nozzle having the same structure as that in FIG. The pattern shook and a stable spray pattern could not be formed.

  Since the present invention can stably spray mist with a uniform water amount distribution and collision force distribution, it is suitable for cooling continuously cast slabs and hot rolled steel plates.

DESCRIPTION OF SYMBOLS 1,23 ... Injection nozzle 2,4,6 ... Cylindrical flow path 2a ... Liquid inflow port 3 ... Orifice part 5 ... Liquid turning member 5a ... Cylindrical member 5b ... Spiral flow path 7 ... Gas flow path 7a ... Gas flow Inlet 8 ... Partition 9 ... Mixing chamber 10 ... Throat part 11 ... Spray pattern forming part 12 ... Outlet 21, 22 ... Header

Claims (15)

  A liquid flow path capable of swirling liquid, a gas flow path capable of swirling gas, a mixing chamber for mixing the liquid and the gas that have merged after passing through each flow path, and a mist generated in the mixing chamber An injection nozzle provided with an injection port for injecting gas, wherein the swirl direction of the gas flow path and the swirl direction of the liquid flow path are opposite to each other.   A cylindrical liquid flow path is provided along the central axis of the nozzle, a liquid swirling member is provided in the liquid flow path, and a gas flow path is provided on the outer periphery of the liquid flow path with a partition wall therebetween. The injection nozzle according to claim 1, wherein a gas inlet capable of swirling gas is formed in the flow path.   The liquid swirl member is formed with a cylindrical member and a plurality of spiral flow paths formed at equal intervals in the circumferential direction of the cylindrical member and spirally inclined at a predetermined angle with respect to the axial direction of the cylindrical member. The injection nozzle according to claim 1 or 2, wherein   A plurality of gas inlets are formed on a side surface of the gas flow path, and the flow path of each gas inlet is spiral in the liquid swirl member with respect to the direction toward the central axis of the nozzle in a cross section perpendicular to the nozzle axis direction. The injection nozzle according to claim 1, wherein the injection nozzle is inclined at a predetermined angle in the same direction as the spiral direction of the channel.   The injection nozzle according to any one of claims 1 to 4, wherein in the nozzle axis direction, the length of the liquid swirling member is 1.5 to 8 times the length of the mixing chamber.   2. A conical channel whose diameter concentrically expands in the downstream direction is formed on the downstream side of the mixing chamber, and the shape of the injection port located at the tip of the conical channel is substantially circular. The injection nozzle in any one of -5.   The injection nozzle according to any one of claims 1 to 6, wherein a throat portion is interposed between the mixing chamber and the spray pattern forming portion.   The injection nozzle according to any one of claims 2 to 7, wherein an orifice portion having a narrower diameter than the liquid flow path is formed on the upstream side of the liquid swirl member.   The injection nozzle according to claim 8, wherein a flow path diameter of the orifice portion is 1 mm or more.   The jet nozzle according to claim 1, wherein the gas is air and the liquid is water.   The method to inject mist using the injection nozzle in any one of Claims 1-10.   12. The method of claim 11, wherein a full cone pattern mist is sprayed.   A long cylindrical first header for supplying liquid, a long cylindrical second header for supplying gas, and a distance in the longitudinal direction of these headers. An injection nozzle device comprising a plurality of injection nozzles attached through, wherein the plurality of injection nozzles are the injection nozzles according to any one of claims 1 to 10, and the liquid flow of the injection nozzles An injection nozzle device in which a path leads into a first header and a gas flow path leads into a second header.   The injection nozzle device according to claim 13, wherein the injection nozzles are attached to the header at equal intervals with a pitch of 40 to 120 mm.   15. A method for cooling a steel sheet by spraying a full cone pattern mist that spreads at an angle of 15 to 90 [deg.] From each spray nozzle of the spray nozzle device according to claim 13 or 14.

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