Abstract: A handling line that includes a valve in a feed line that sets the valve to a respective opening position (s) for adjusting a coolant flow (F) to a metal strip per unit of time; an upstream condition detection device upstream of the valve device in the feed line that detects an upstream condition (ZV) of the coolant; a control unit that determines a set point (s*) for an opening position (s) of the valve device corresponding to the set point (F*) for the coolant flow (F) based on a set point (F*) for the coolant flow (F*), the upstream condition (ZV) of the coolant and a valve characteristic (C) of the valve device.

Abstract: In some examples, an apparatus includes a pallet supporting a plurality of workpieces, the pallet including through-holes structured to pass a quenching fluid. In some examples, the apparatus further includes a reservoir of quenching fluid configured to provide the quenching fluid, and a plurality of upturned wall portions extending from the pallet and substantially surrounding the exteriors of the plurality of workpieces. The plurality of upturned wall portions may be located in relative orientation to the plurality of workpieces to regulate heat transfer coefficients of the plurality of workpieces during a quenching operation.

Abstract: A method of manufacturing a hollow element which has an internal space and of which the internal space is cryogenically used, the method comprising a base material forming step of forming a base material which has a space to serve as the internal space; a filling step of filling the internal space of the formed base material with fluid having a temperature equal to or lower than a temperature at which the base material is subjected to solid-phase transformation and causing the base material to be subjected to the solid-phase transformation; and a finishing step of finishing the base material after the base material is subjected to phase transformation.

Abstract: Provided is a coolant spray module system for a heat treatment metal product, comprising: a first coolant spray module (1A), wherein the first coolant spray module (1A) comprises a first module housing (10), a first module cover (20), and a first nozzle (30), wherein the first nozzle (30) is fixed between the first module housing (10) and the first module cover (20) by first nozzle fixing blocks (13) and second nozzle fixing blocks (23), wherein the coolant spray module system sprays the coolant onto the heat treatment metal product to quench and clean the heat treatment metal product.

Abstract: A flat rolled article (2) passes through a cooling device (1) in a transportation direction (x) at the level of a passline (3). Spray bars (5, 6) extend transversely with respect to the transportation direction (x). The spray bars (5, 6) have, as viewed perpendicular to the transportation direction (x), in each case two outer regions (7, 8) and a central region (9) in between. A liquid cooling medium (13) can be fed into the regions (7, 8, 9) via respective dedicated, individually controllable valve devices (10, 11, 12). Flow rate profiles, pertaining to each region may be set, wherein each region (7, 8, 9) is triangular in shape. The central triangle and the two outer triangles combine to form a rectangle.

Abstract: Provided are a cooling method and a cooling apparatus that, in the cooling of a hot-rolled steel strip, regulates the amount of cooling water in a two-stage manner for each set of headers in the width direction and changes the rate at which the steel strip is cooled, in a multistage manner by a simple method, and that is effective particularly in cooling the lower surface of the steel strip, where space is narrow. The spray nozzles 5 are arranged in a row in the width direction of the steel strip at a predetermined pitch. Two systems of cooling headers 6 are arranged for one set so that spray nozzles 5 adjacent in the width direction can be supplied with cooling water from different pipe systems, and a spray valve 7 is attached to each cooling header 7 so that spraying/stop of spraying of cooling water can be individually performed.

Abstract: A water-blocking apparatus for cooling water for a hot-rolled steel sheet according to the present invention, which blocks cooling water sprayed onto a hot-rolled steel sheet at a sprayed water density of higher than 4 m3/m2/min and equal to or less than 10 m3/m2/min when the hot-rolled steel sheet is cooled after finish rolling of a hot-rolling process, includes: a plurality of water-blocking nozzles which spray water-blocking water onto the hot-rolled steel sheet. Impact areas of the water-blocking water respectively sprayed from the water-blocking nozzles are continuously lined up in a straight line in a width direction of the hot-rolled steel sheet on a surface of the hot-rolled steel sheet and the adjacent impact areas partially overlap.

Abstract: A rail heat treatment device includes a cooling header, an oscillation mechanism, and a control system including: a storage unit that stores therein at least information required for a oscillation control; and a control unit that obtains a permissible range of required cooling time for a rail that satisfies a permissible range of hardness of the rail based on a correlation expression representing a correlation between the cooling time for the rail with the cooling header and the hardness of the rail after cooling, controls a stroke and a speed of relative reciprocation of the rail and the cooling header based on the permissible range of the required cooling time, and causes the oscillation mechanism to perform the relative reciprocation of the rail and the cooling header by the stroke and at the speed.

Abstract: A spray quench system is provided with one or more spray quench rings that eject a controlled volume of quenchant spray onto a workpiece passing through the quench rings. Supply of the quenchant to the quench rings is coordinated with control of the quench rings to selectively change the pressure, quenchant spray exit velocity from the quench rings, flow rate or pattern of the quenchant spray onto the workpiece depending upon mass cooling requirements as the workpiece passes through the quench rings.

Abstract: A method of quenching a workpiece is provided with one or more spray quench rings that eject a controlled variable volume of spray quench onto a workpiece passing through the quench rings by dynamically adjusting the axially adjustable distance between the inner and outer ring elements of each quench ring while the workpiece passes through the quench rings in response to mass cooling requirements of the workpiece passing through the quench rings. The quench rings can also be axial adjusted relative to each other in response to the mass cooling requirements. Dynamically adjustable reflected spray guards can be provided to prevent quench spray pattern interference between adjacent quench rings.

Abstract: The present invention provides a method of cooling a hot-rolled steel strip which has passed through a finishing rolling, including: cooling the hot-rolled steel strip from a first temperature of not lower than 600° C. and not higher than 650° C. to a second temperature of not higher than 450° C. with cooling water having the water amount density of not lower than 4 m3/m2/min and not higher than 10 m3/m2/min, wherein with respect to the area of the target surface, the area of a portion where a plurality of spray jets of the cooling water directly strikes on the target surface is at least 80%.

Abstract: Systems and methods for cooling a heat-treated metallic part include a plurality of atomization nozzles disposed on a stage and radially disposed about the part to be cooled; and a fluid in fluid communication with the atomization nozzles. The fluid may gas, liquid, or a combination thereof, e.g., water and gas. During use, the atomization nozzles are generally configured to rapidly cool the thicker sections of the part relative to the thinner section since the thicker sections are generally slower to cool. In some embodiments, the stage can be configured to rotate about the part during cooling. Methods are also disclosed.

Abstract: A hydrometallurgical plant for nickel laterite ore extraction having a plurality of treatment facility lines wherein the plant is capable of minimizing a decrease in throughput when line failure occurs and efficiently restoring normal operation status Each line of the treatment facility includes a pretreatment step, a leaching step, a solid-liquid separation step, a neutralization step, a zinc removal step, a sulfurization step and a detoxification step. The lines are coupled by pipelines, each having a valve, installed after the solid-liquid separation step for sending a liquid from the solid-liquid separation step to the neutralization step in each line and/or after the sulfurization step for sending a liquid from the sulfurization step to the detoxification step in each line.

Abstract: A charging frame for accommodating a batch of parts to be quenched, e.g., metal workpieces, has a circumferentially closed peripheral wall which surrounds the batch and thereby forms a flow channel which prevents bypass flows. The charging frame is a part of a quenching device.

Abstract: In some examples, an apparatus includes a pallet supporting a plurality of workpieces, the pallet including through-holes structured to pass a quenching fluid. In some examples, the apparatus further includes a reservoir of quenching fluid configured to provide the quenching fluid, and a plurality of upturned wall portions extending from the pallet and substantially surrounding the exteriors of the plurality of workpieces. The plurality of upturned wall portions may be located in relative orientation to the plurality of workpieces to regulate heat transfer coefficients of the plurality of workpieces during a quenching operation.

Abstract: A cooling chamber is provided which cools workpieces that have been heated. Cooling units are provided in the cooling chamber, and respectively include: a conveyor which simultaneously and uniserially conveys a plurality of workpieces; a mist cooling device which is disposed so as to surround the conveyance path of the conveyor and which supplies mist-like cooling liquid; and a gas cooling device which is disposed so as to surround the conveyance path of the conveyor and which supplies cooling gas.

Abstract: A cooling system that cools hot rolled long steel bar, provided with a plurality of chambers that are arranged along the longitudinal direction of the rolled steel bar. Each of the plurality of chambers is provided with a blow outlet that, facing from the chamber to the rolled steel bar, blows out compressed air for cooling that is introduced to the chamber from a gas inlet that is connected to the chamber; a nozzle plate having a plurality of nozzle holes that is provided at this blow outlet so as to face the rolled steel bar; a cooling water supply nozzle that supplies cooling water into the chamber; and a rectifying plate that is provided between the gas inlet and the cooling water supply nozzle, and that prevents the compressed gas for cooling that is introduced from the gas inlet from directly striking the nozzle plate.

Abstract: A process for the recovery of gold from a gold-bearing aqueous filtrate, the process comprising the steps of: (A) Contacting the aqueous filtrate with dibutyl carbitol (DBC) in a two-stage solvent extraction process to remove the gold from the aqueous filtrate into the DBC to form a gold-loaded DBC; and (D) Contacting the gold-loaded DBC with an aqueous acid scrub of hydrochloric acid in a four-stage countercurrent scrub process to remove impurities, e.g., non-gold metal, from the DBC into the aqueous scrub solution to form an impurity-loaded aqueous scrub. Each stage of the solvent extraction circuit and the aqueous acid scrub circuit is equipped with a mixing assembly and a phase separation tank in a head-tail arrangement such that the mixing assembly of one stage is adjacent to the phase separation tank of the adjacent stage.

Abstract: A process and apparatus for quenching a metal workload from an elevated heat treating temperature are disclosed. The process includes the step of flowing a vegetable oil quenchant over the metal workload to provide a cooling rate sufficient to transform the metal substantially completely to a desired second phase comprising martensite, bainite, pearlite, or a combination thereof within a preselected time period. The apparatus includes a quenching chamber that has a base, an upper housing, a door, and an associated actuator for opening and closing the quenching chamber. The apparatus also includes a vessel for holding a volume of a vegetable oil quenchant, means for conducting the vegetable oil quenchant from the vessel to the quenching chamber, and means disposed in the quenching chamber for flowing the vegetable oil quenchant over a metal workload disposed in the quenching chamber.

Abstract: A process and apparatus for refining iron from high-phosphorus content iron ores. The process involves mixing a high-phosphorus iron oxide ore and an alkaline solution of pH between about 12.5 and 13.5, screening the mixture by gravity to separate an alkaline-high-phosphorus solution from a low-phosphorus iron ore; and treating the low-phosphorus iron ore with lime and a natural gas.

Abstract: A handling machine for handling rails, arranged in line immediately downstream of a rolling plant, which allows an optimal clamping of the rail along its longitudinal extension, thus effectively withstanding the deflection and its variations, while allowing a longitudinal movement of the rail caused by thermal shrinkage, thus avoiding damages both to the external surface of the rail and to the handlers. A process of handling the rail is also described, which optimizes moving, positioning along a roller table and maintaining the rail substantially rectilinear during the thermal treatment to which it is subjected.

Abstract: An annular workplace quenching method includes: cooling an annular workpiece with an inner die arranged radially inward of the workpiece heated at a quenching temperature; pressing the workpiece in a width direction at a low pressure and inserting the workpiece in an outer die with restraint of an inner peripheral surface of the workpiece continued, when the restraint is started by contact with the inner die, after a temperature of the workpiece is decreased to 500° C. or lower but before the temperature is decreased to a martensitic transformation start temperature (Ms point); and restraining the workpiece in the width direction by pressing the workpiece in the width direction at a high pressure, and restraining an outer peripheral surface of the workpiece that undergoes volume expansion due to martensitic transformation, using the outer die, after the temperature of the workpiece is decreased to the Ms point or lower.

Abstract: A spray quench system is provided with one or more spray quench rings that eject a controlled volume of quenchant spray onto a workpiece passing through the quench rings. Supply of the quenchant to the quench rings is coordinated with control of the quench rings to selectively change the pressure, quenchant spray exit velocity from the quench rings, flow rate or pattern of the quenchant spray onto the workpiece depending upon mass cooling requirements as the workpiece passes through the quench rings.

Abstract: Provided is a cooling system for a hot-rolled steel strip capable of increasing the cooling rate for rapidly cooling a rolled steel immediately after rolling and suitable for an apparatus for manufacturing a hot-rolled steel strip having a fine-grained structure. For this purpose, guides (16A, 16B) having guiding surfaces (16a, 16b) to guide a rolled steel (W) exiting work rolls (12A, 12B) in the conveyance direction are provided at exits of the work rolls in a final stand (Sn) of a finish rolling mill line in a manner that the guides can follow a change in the diameter of the work rolls, a number of injection holes (21A, 21B) are formed in the guides, and a number of rolled steel cooling nozzles (23A, 23B) are provided to spray a large amount of cooling water through the injection holes directly onto the rolled steel.

Abstract: Porous leach pipe and method for leaching metals from mining ores. The porous pipe may be buried beneath the surface of a pile of mined ore, providing a more even and uniform distribution of the leaching solution across the pile, increasing metal yields, reducing water consumption and eliminating pooling and ponding of the solution on the top of the piles as occurs with prior art drip line emitters.

Abstract: A wet smelting plant for nickel oxide ore is provided in which, even when a serious trouble occurs in a processing facility, the preparation period of time of the processing facility required for discontinuing and restarting the operation can be minimized.

Abstract: A method and a device adjust the cooling of a steel strip in an annealing or galvanization phase. The device is suitable for the forced cooling of a steel strip continuously running in a plant adapted for the continuous annealing or the continuous tempering galvanization. The device has at least one exchange member for transferring the heat of the steel strip to cooling water and includes an outlet for the cooling water thus heated up. At least one cooling unit is provided and has a sealed enclosure connected to the outlet of the exchange member and includes at least one outlet to a Venturi effect device such as a vapor outlet ejector and in which the cooling water itself is subjected to a vacuum-vaporization cooling. An auxiliary outlet of the sealed enclosure is connected to an inlet of the exchange member.

Abstract: A cooling unit, a heating-cooling operation including a cooling unit, a rod or wire manufacturing system, a method for manufacturing a rod or wire, a method for heat treating of a rod or wire, a method for treating metal, a steel rod or steel wire, and a treated metal having an improved tensile strength are disclosed. The cooling unit includes at least one adaptable quenching zone and at least one adaptable soaking zone. The at least one adaptable quenching zone is capable of quenching to a soaking temperature. The at least one adaptable soaking zone is capable of maintaining substantially the soak temperature.

Abstract: A spray quench system is provided with one or more spray quench rings that eject a controlled volume of spray onto a workpiece passing through the quench rings. The quench rings can be adjusted in position independently of each other relative to the workpiece being sprayed. Reflected spray guards may be provided to prevent spray interference between adjacent quench rings. The outlets of the quench rings may be adjustable in volume. A controller can be provided to optimize the distribution of quench cooling flows from the quench rings. Sets of quench rings with different diameters in each set may be provided in modular form.

Abstract: The present invention provides a manufacturing apparatus of a hot-rolled steel sheet capable of cooling control of a steel sheet even when disposing a cooling device capable of cooling from inside a finishing mill. The manufacturing apparatus of a hot-rolled steel sheet comprises: an immediate rapid-cooling device capable of spraying cooling water, at least a part thereof being disposed inside a final stand in the row of hot finishing mills; a device for measuring a temperature on an entry side of a final stand; a device for measuring a steel sheet passing speed; a device for predicting a rapid-cooling stopping temperature which calculates a predicted rapid-cooling stopping temperature; and an immediate rapid-cooling control device which corrects the water supply volume or water supply pressure of the immediate rapid-cooling device such that the predicted rapid-cooling stopping temperature matches a targeted rapid-cooling stopping temperature.

Abstract: A load transport mechanism for moving a heat treating load in a multi-station heat treating system is disclosed. The transport mechanism has a compact construction that allows it to fit in a centrally located stationary transport chamber. The transport chamber is adapted to provide ready access to multiple treating chambers arrayed around the chamber. The transport mechanism includes a load translation mechanism for moving the load linearly and a load rotation mechanism for rotating the load within the transport chamber. A multi-station heat treating system having a centrally located quenching chamber that includes the load transport mechanism is also disclosed.

Abstract: A hot-strip cooling device for cooling a hot strip that has been subjected to finish rolling while being conveyed over a run-out table. The device includes a plurality of cooling nozzles that are disposed above a steel strip and eject rod-like flows of coolant at an ejection angle tilted toward the upstream side in a steel-strip traveling direction; and purging means that is disposed on the upstream side with respect to the cooling nozzles and purges the coolant that has been ejected from the cooling nozzles and resides on the steel strip.

Abstract: The present invention provides a cooling apparatus of a hot-rolled steel sheet capable of manufacturing a hot-rolled steel sheet having ultra fine crystal grains. In the cooling apparatus, when defining as L1, a length in a transporting direction of a steel sheet, of a zone from a rolling reduction point in a final stand to an exit side of a housing post; defining as L2, a length in the transporting direction of the steel sheet, of an area where high-pressure water is continuously sprayed over the steel sheet, within the zone; and defining a ratio of L2/L1 as X, an average value Ps [kPa], in the transporting direction of the steel sheet, of an impact pressure of the high-pressure water on a surface of the steel sheet in the area of the length L2 satisfies Ps?2.5X(?1/0.6) on the above upper surface and lower surface of the steel sheet.

Abstract: The invention relates to a method for the extraction of precious metals, using halogens. It has been found that introducing halogens in the reactor in the form of hypohalites rather than free halogens simplified greatly the recycling of halogens by electrolysis. It increases the rate of addition of the halogens and significantly reduces secondary reactions with base metals such as iron. Operating under acidic conditions, the gold recovery has been found as high with hypochlorite as with elemental chlorine, with an active chlorine to ore ratio reduced by a factor of two to five.

Abstract: A cooling device and a cooling method for a hot strip allow uniform and stable cooling of the strip at a high cooling rate when supplying the coolant to the upper surface of the hot strip. The cooling device includes an upper header unit 21 for supplying a rod-like flow to the upper surface of the strip 10. The upper header unit 21 is formed of the first upper header group including plural first upper headers 21a arranged in a conveying direction and a second upper header group including plural second upper headers 21b arranged in the conveying direction. The cooling device is provided with an ON-OFF mechanism 30 to allow each of the upper headers 21a and 21b of the first and the second upper header groups to independently execute the ON-OFF control (start/end injection control) of an injection (feeding) of the rod-like flow.

Abstract: The mist cooling apparatus (3) includes: a cooling system (30) which includes a nozzle (35, 35A) that sprays cooling liquid in a form of a mist onto a treatment object which has been heated and provided in a cooling furnace (10), and a pump (33) that is driven by a drive source and thereby makes the cooling liquid flow toward the nozzle (35, 35A); and a second cooling system (40) which operates in response to a stoppage of the drive source, and thereby cools the treatment object.

Abstract: A process and apparatus for refining iron from high-phosphorus content iron ores. The process involves mixing a high-phosphorus iron oxide ore and an alkaline solution of pH between about 12.5 and 13.5, screening the mixture by gravity to separate an alkaline-high-phosphorus solution from a low-phosphorus iron ore; and treating the low-phosphorus iron ore with lime and a natural gas.

Abstract: A method for preparing metal-matrix composites including cold-process isostatic compaction of previously mixed powders and hot-process uniaxial pressing of the resulting compact is disclosed. The method enables metal-matrix composites with improved properties to be obtained. A device for implementing isostatic compaction comprising a latex sheath into which the mixture of powders is poured, a perforated cylindrical container in which the latex sheath is arranged, and means for sealed insulation of the mixture of powders contained in the sheath is also disclosed.

Abstract: The present invention provides a method of cooling a hot-rolled steel strip which has passed through a finishing rolling, including: cooling the hot-rolled steel strip from a first temperature of not lower than 600° C. and not higher than 650° C. to a second temperature of not higher than 450° C. with cooling water having the water amount density of not lower than 4 m3/m2/min and not higher than 10 m3/m2/min, wherein with respect to the area of the target surface, the area of a portion where a plurality of spray jets of the cooling water directly strikes on the target surface is at least 80%.

Abstract: A device and a method for cooling a hot strip capable of uniformly cooling the hot-rolled steel strip from the leading end to the trailing end thereof during cooling of the steel strip using cooling water are provided. A cooling device 10 includes a plurality of tubular nozzles 15 inclined so as to eject rod-like flows of cooling water to a steel strip 12 at an ejecting angle ? in a traveling direction of the steel strip 12 and a pinch roller 11 disposed downstream of the tubular nozzles, the steel strip 12 to be nipped between the pinch roller 11 and a table roller 8.

Abstract: The invention relates to a device for loading and unloading a heat treatment furnace and to a corresponding method. Heat treatment furnaces are normally loaded and unloaded by means of a so-called elevator. During unloading, a removed workpiece is usually lowered by means of the elevator into an oil bath, in which it is then removed from the elevator. Oil is then transferred into the furnace chamber via the oil-covered elevator. Such an application of oil is avoided by means of a device comprising a frame rack having a first and a second level, which are disposed parallel above each other, and are connected to each other by means of a plurality of frame braces, wherein the first and the second levels have a plurality of openings and the frame braces have guide means.

Abstract: A process for quenching heat treated metal parts using a liquid quenchant and high pressure is disclosed. In general, the process includes the steps of providing a load of heat treated metal parts in a pressure vessel wherein the load is at an elevated temperature after being heat treated. In a subsequent step, a liquid quenchant is injected into the pressure vessel such that a vapor of the liquid quenchant forms rapidly in the pressure vessel and cools the metal parts. The step of injecting the liquid quenchant into the pressure vessel is continued for a time sufficient to establish a desired peak vapor pressure in the pressure vessel. An apparatus for carrying out the disclosed process is also described.

Abstract: The invention adopts a mist cooling apparatus (3) that cools a heated treated subject M by spraying a cooling mist thereto, the mist cooling apparatus including: a first nozzle (35) that sprays a cooling mist; and a second nozzle (45) that sprays a cooling mist having a particle diameter smaller than the particle diameter of the cooling mist sprayed from the first nozzle.

Abstract: A hot-strip cooling device and a cooling method are provided wherein uniform cooling of a hot-rolled steel strip using coolant is possible from the leading end to the trailing end of the steel strip. A cooling device (10) includes a plurality of round nozzles (15) disposed obliquely in such a manner as to eject rod-like flows of coolant at an ejection angle ? toward the upstream side in a direction in which a steel strip (12) travels, and a pinch roll (11) disposed on the upstream side with respect to the round nozzles (15) and configured to pinch the steel strip (12) in combination with a roller table (8).

Abstract: A method and system are provided in which a gold and/or silver-collecting resin-in-leach circuit comprises both co-current and counter-current sections.

Abstract: In a hydrometallurgical plant of a nickel laterite ore having a plurality of lines of treatment facilities, the hydrometallurgical plant of the nickel laterite ore which is, even when a serious trouble will occur in said treatment facilities, capable of minimizing decrease in throughput caused by this, and restoring a normal operation state early, after eliminating the serious trouble, and an operation method thereof. A hydrometallurgical plant of a nickel laterite ore having a plurality of lines, as treatment facilities including a pretreatment step, a leaching step, a solid-liquid separation step, a neutralization step, a zinc removal step, a sulfurization step and a detoxification step as one line, wherein a coupling pipeline having a valve is installed between a liquid sending pipeline from the solid-liquid separation step to the neutralization step in each line and/or between a liquid sending pipeline from the sulfurization step to the detoxification step in each line.

Abstract: Porous leach pipe and method for leaching metals from mining ores. The porous pipe may be buried beneath the surface of a pile of mined ore, providing a more even and uniform distribution of the leaching solution across the pile, increasing metal yields, reducing water consumption and eliminating pooling and ponding of the solution on the top of the piles as occurs with prior art drip line emitters.

Abstract: An improved method and system is described for applying a leach solution to ore in the process of heap leaching. The Hybrid Irrigation System (HIS) relies on both surface solution delivery techniques as well as sub-surface solution application to improve the solution uniformity and metallurgical performance of a leaching process. The methods and systems allow for controlled application of leach solution with a hydraulic head applied that can be adjusted or varied depending on the conditions of the ore from negative, atmospheric or positive pressure, while distributing leaching solution in a uniform manner independent of surface variability with respect to elevation and infiltration capacity of the ore surface.

Abstract: A system and method for recovering a metal value from a metal-bearing ore material are provided. A metal-bearing ore can be mixed with certain substances and to form an agglomerated ore. In an intermediate state, between agglomeration and heap formation, bacteria can be added to the metal-bearing ore material to produce an augmented ore. The augmented ore can then be formed into a heap.

Abstract: A cooling apparatus of a steel sheet, which is excellent in discharging water without hindering the movement of a steel sheet, is disposed on a lower process side of a final stand in a row of hot finish rolling mills. The apparatus includes a plurality of cooling nozzles arranged to cool a steel sheet transported on transporting rolls, wherein the cooling nozzles are arranged on upper and lower surface sides of an area in which the steel sheet passes. A lower surface guide is arranged on the lower surface side with the lower surface guide comprising inlet holes through which cooling water sprayed from the cooling nozzles on the lower surface side passes and outlet holes through which the cooling water passes, dropping downwardly to be discharged. The inlet holes and the outlet holes are arranged alternately in a moving direction of the steel sheet.