Abstract: The present invention is to provide a cooling system for cooling a strip in a vertical path of a continuous strip heat-treating process in which cooling nozzles are arranged in a width direction of a strip on the surfaces of cooling headers arranged closely opposed to both surfaces of the strip, and each cooling nozzle is inclined to both edge portions in the width direction of the strip by an inclination angle in such a manner that a center line of a jet of a cooling medium, which is jetted out from the cooling nozzle, is inclined with respect to a normal line at a position on the strip surface where the center line of the jet of the cooling medium crosses the strip.

Abstract: Disclosed herein are a composition comprising an aqueous solution of a gluconate salt and a citrate salt for treatment of a ferrous metal surface, and a method of application of such a composition for the protection of the ferrous metal surface against corrosion by inhibition of the formation of stop stain caused by the flash rusting.

Abstract: Device for the accelerated cooling of a continuous substrate moving rapidly in a vertical plane, formed by a closed chamber, which includes, in succession in the direction of travel of the substrate, at least one so-called main cooling zone provided with coolant injectors, a so-called secondary cooling zone promoting contact between the coolant and the substrate, a coolant extraction zone and coolant retainers both at the inlet and outlet of the cooling device. The main cooling zone includes, spray injectors for forming one or more water/air fog curtains arranged in space so that they come into direct contact with the substrate to be cooled.

Abstract: This invention relates to a process for heat treating light-metal castings, particularly cylinder heads for piston engines, in which, after solidifying and removing the castings from the mold, they are solution treated with the residual casting heat at approximately 530.degree. C., are quenched, aged at approximately 170 to 210.degree. C. and are then cooled to room temperature. The castings are quenched individually with a mist-type fine mixture of air and water, which is nozzle sprayed on all sides by forced convection flow only to approximately 130 to 160.degree. C., and are charged at this temperature, while utilizing the residual heat, into an aging furnace. The evaporation heat of the water is utilized as latent cooling heat. The forming water vapor, carried away by the workpieces, is condensed and the condensed water is guided back to moisten the air/water mixture.

Abstract: A heat treatment system for treating an impact beam is disclosed.

Abstract: A method operating a pickling installation for pickling rolled strips comprises several consecutively disposed pickling basins filled with a pickling agent containing acid, through which the strip 4 is passed. A pickling agent containing acid is injected through injection nozzles disposed at least on the sides of the basin. A flexible adaptation to the respective pickling task with the aim of a reduced pickling time period is made possible if the nozzle injections on the sides are actuated variably. The pickling installation is provided for this purpose on both sides of the plurality of the basins, with injection nozzles above and below the strip traveling plane and upstream or downstream of base slide pads located in the basin.

Abstract: An apparatus for cooling hot ceramic articles from above and below with steam and water.

Abstract: The spray unit lies downstream, in-line with an extrusion press and serves to cool metallic sections in particular sections of aluminum or an aluminum alloy from all sides. The cooling medium emerges from spray nozzles program-controlled in the direction of the section. The distance, the cross-section distribution and the direction of the spray nozzles are adapted specific to the geometrical shape and distribution of mass in the section. The optimum parameters are determined and stored in the unit processor. The spray nozzles are arranged in nozzle beams running in the direction of the extruded section. The nozzle beams comprise at least one longitudinal water channel and two longitudinal air channels, whereby cross-intersecting channels branch off from the water channels to the spray nozzles and the air channels terminate in air gaps which are directed towards the nozzle outlets.

Abstract: An apparatus and method for cooling a metal strip, the apparatus having a header that receives and directs a curtain of water across the strip, a water collector on one side of the curtain of water and a source of air on the opposite side of the curtain of water arranged to direct a flow of air across the curtain of water and divert water into the water collector. A deflector is arranged to interrupt at least a portion of the flow of air such that at least a portion of the wall of water contacts and cools the strip of metal. The flow of air is provided at a pressure of about 50 to 100 psi and, with the flow of air completely blocked by a deflector, the strip of metal is cooled completely across the width of the strip.

Abstract: Descaling device employing water to descale blooms, thin slabs, billets, etc., which cooperates with a mould and the zone immediately downstream therefrom, or with an induction furnace or rolling mill stands, the slabs or blooms (11-24) being fed in cooperation with the descaling device at a speed of feed of the order of 1.5-20 meters per minute, but advantageously between 4 and 10 meters per minute, the device consisting of at least one movable arm (12-13) bearing nozzle means (14) delivering descaling water, the movable arm (12-13) being associated with the face of the slab or bloom (11-24) to be descaled and having a working phase, in which the descaling water acts on the surface of the slab or bloom (11-24), and a shut-off phase, in which the descaling water does not act on the surface of the slab or bloom (11-24).

Abstract: Apparatus for cooling a metal extrusion, such as an aluminum extrusion, may include a carriage which houses the cooling liquid delivery system and is relatively movable with respect to the extrusion press in order to provide the desired amount of air cooling prior to quenching. The quenching apparatus may have a plurality of generally parallel cooling liquid delivery tubes, each having a plurality of nozzles which are preferably independently adjustable as to volume and spray pattern. The cooling liquid delivery tubes may be axially rotated and flow of the cooling liquid within each tube may be independently adjusted. The housing of the quenching unit may have an upper portion which is rotatable generally upwardly and is provided with a transparent window to facilitate viewing of the spraying action. A method of quenching an aluminum extrusion employing such apparatus is provided.

Abstract: A water box is used to cool hot rolled products in a rolling mill. The water box includes a base structure supporting a removable manifold, and a plurality of nozzles removably mounted on and in fluid communication with the manifold. The nozzles are lined with inserts which may be replaced when worn. The manifold is reversible end to end, as are the nozzles, thus enabling the water box to be used on either of two parallel rolling lines.

Abstract: A cooling system for cooling a metal strip moving horizontally along a roller conveyor has a plurality of water boxes (4) arranged between the rollers (1,2,3) of the roller conveyor and each having upwardly directed outlet ducts (6) from which cooling water is projected onto the underside of the metal strip. The ducts (6) are parallel to each other and uniformly spaced across the width of the strip. To improve cooling, particularly its uniformity, the outlet ducts (6) are all shaped and oriented so as to project the cooling water with a component of motion opposite to the direction of movement of the metal strip, and each water box (4) is shaped and located relative to the next preceding roller (1,2,3) in the direction of movement of the metal strip so that during operation the water projected from each water box also cools said next preceding roller.

Abstract: A conveyor defines a path along which hot rolled steel rod is transported in the form of overlapping mutually offset rings. Air nozzles are arranged beneath the conveyor path to direct air upwardly against the rings from underlying plenum chambers fed by motor driven fans. Additional water nozzles are arranged to apply water to the rings. Some of the thus applied water is vaporized by the heat of the rod, and the remainder of the water is drained through the air nozzles into the plenum chambers for subsequent removal.

Abstract: A laminate material of a laminate workpiece with a backing layer and a functional layer, in particular a friction bearing layer with the structure of a solid but fusible dispersion with a matrix and at least one component which is dispersed in the matrix and which at least in the solid condition is insoluble in the material of the matrix or is soluble only in an amount smaller than the amount present, or with the structure of a substantially fusible mixture, which is fixedly combined in itself and which can be used for tribological purposes, of components which are not soluble in each other or which are soluble in each other only in an amount smaller than the amount present, possibly partially in crystal-like form, is transformed into another structure in respect of the dispersion alloy or the mixture at the exposed surface of the functional layer by means of a surface treatment, more specifically by melting and very rapid cooling from the molten condition, so that fine distribution of the undissolved compone

Abstract: A cooling apparatus for a cylindrical member in linear motion comprises a tubular conduit through which the cylindrical member passes axially, an envelope surrounding the tubular conduit and forming therewith an annular chamber therebetween closed at its ends by an upstream wall and a downstream wall, respectively, cooling agent being introduced into the annular chamber. The tubular conduit is pierced radially by a plurality of a straight passages providing communication between the annular chamber and the internal space in the tubular conduit. These passages are located in planes perpendicular to and axially spaced along the longitudinal axis of the tubular conduit and are equally circumferentially spaced within each plane and angularly displaced with respect to the passages in the adjacent planes. Cooling agent passes through the passages radially inwardly and is drained from the internal space of the tubular conduit.

Abstract: In the manufacture of formable steel strip having a thickness between 0.5 and 1.5 mm, the following process steps are performed sequentially in a continuous process:(a) in a continuous casting machine forming liquid steel into a hot slab having a thickness of less than 100 mm,(b) hot rolling the hot slab from step (a), in the austenitic region and below 1100.degree. C., to form strip having a thickness of between 2 and 5 mm,(c) cooling the strip from step (b) to a temperature between 300.degree. C. and the temperature T.sub.t at which 75% of the steel is converted to ferrite,(d) rolling the cooled strip from step (c) at said temperature between 300.degree. C. and T.sub.t with a thickness reduction of at least 25% at a rolling speed not more than 1000 m/min.,(e) coiling the rolled strip from step (d).

Abstract: A method and apparatus for cooling samples of hot rolled steel sections. A programmable controller directs a predetermined sequence of air and cooling water sprays against the sample while held in a closed container. The controlled cooling of the sample prevents dimensional distortion of the sample so that accurate measurements of the finished hot rolled steel section can be determined.

Abstract: Apparatus for cooling at least two bars travelling in parallel linear paths after having been formed from a larger bar in a rolling mill, comprises a common antechamber for receiving the bars, a cooling water inlet and a cooling water outlet communicating with the antechamber, first and second common nozzle chambers, the first nozzle chamber being arranged for receiving the bars from the antechamber and the second nozzle chamber being arranged for receiving the bars from the first nozzle chamber, each of the nozzle chambers being provided with a respective cooling water inlet communicating with the respective nozzle chamber through a respective equalizing chamber, each of the nozzle chambers containing for each of the bars a respective funnel for guiding the bar and a nozzle for receiving the bar from the funnel, the nozzle having passages for conducting water from the chamber into contact with the bar, communicating with each of the nozzles a respective heat exchanger pipe for receiving a respective one of t

Abstract: Disclosed is an improvement of final cooling of the steel strip by immersing in cooling water, which strip has been cooled through a cooling zone in a continuous heat treating line. The improvement is achieved by injecting cooling water to the surface of the immersed strip to rapidly cool the strip to a predetermined temperature until the strip reaches the first sink-roll and resulted in that any dirt adhesion on the surface of the strip caused by contacting with the first sink-roll is prevented without increment of cooling cost.

Abstract: A metal product having at least one plane surface, e.g. steel strip, is cooled by means of an aqueous fluid as it moves along a predetermined path by apparatus comprising a wall disposed opposite the plane surface of the product and substantially parallel thereto so as to form a chamber of substantially constant thickness between the plane surface and the wall, at least one aperture in the wall communicating with the chamber for the passage of the aqueous fluid connected to the aperture through the wall. The aperture is connected to a source of the aqueous fluid. The rate of flow of the aqueous fluid and the spacing between the wall and the plane surface are both adjustable.

Abstract: An apparatus and method for cooling product in a continuous hot-rolling mill. The apparatus comprises a cooling unit including a frame defining a plurality of spaced, cartridge receiving slots in which a plurality of guide and spray cartridges are removably mounted. The guide and spray cartridges are similarly configured so that either cartridge can be mounted in a given frame slot so that the number and ratio of spray to guide cartridges can be varied to modify the cooling characteristics of the cooling unit. Headers, formed integrally with the cooling frame communicate with a source of coolant under pressure and include a plurality of outlets connectable to the spray cartridges by individual conduits. Valves are provided to adjust the coolant flow rate to a cartridge and a quick release coupling is utilized to enable the cartridges to be easily removed for service and/or replacement.

Abstract: The device is intended to facilitate the changing of the sealing element and to increase the life of this element. The device comprises an added bar which is detachably fixed to a wall of the machine and received in a slot in this wall. The bar carries a deformable hollow body which is connected to a source of fluid under pressure and carries the sealing element.

Abstract: The device provides an arrangement of the input and output ends of the machine which is of light and cheap construction, smaller in size and allows an adaptation of the machine in accordance with the width of the product to be treated. The device comprises, for each end of the machine, at least one rigid closing shutter carried by one of the frames of the machine. Guiding devices carried by this frame ensure a displacement of the or each shutter in a direction roughly perpendicular to the plane of the sheet passing through the machine. Devices for shifting the or each shutter are provided. The or each shutter cooperates by its free edge with the other frame of the machine so as to close in a substantially sealed manner the input or output end of the machine.

Abstract: The arrangement is provided in order to limit or prevent leakages of cooling liquid which always occur under various circumstances at the ends of the machine. The arrangement is provided at the input and output ends of the machine for cooling metal sheets or the like, which is of the type comprising an upper frame and a lower frame. Each frame comprises two lateral walls interconnected by a case which defines an enclosure in which the cooling liquid circulates. The arrangement resides in the fact that there are provided, at each of said ends, on one hand, a sump for collecting the cooling liquid and carried by the lower frame and extending throughout the width of the machine and, on the other hand, a device carried by the upper frame and adapted to project toward the interior of the machine a jet of fluid which is directed in counter-current fashion against the cooling liquid which tends to issue from the machine.

Abstract: A cooling apparatus for hot elongated work is formed by a tubular or generally cylindrical cluster of longitudinally extending tubes having interspaced discharge means and surrounding the work so that when the tubes are supplied with cooling fluid the work is showered on all sides.

Abstract: In the manufacture of tubing, and particularly finned tubing, for use by the heat transfer industry in the manufacture of heat exchangers, annealed ends and lands are desirable in certain applications to facilitate the assembly of the tubes to headers and baffles by expanding techniques. Such spot-annealed portions can be produced on a continuous basis by the described apparatus in which the moving tube is passed through a heating chamber which reciprocates on a carriage in the direction of tube movement. The heating chamber has a pair of spaced, power-actuated clamps which grip the tubing at the ends of a discrete length portion. The heating chamber and carriage are moved with the tube while it is clamped to provide sufficient heating time to anneal the discrete length portion. The carriage then returns to its starting position. Heating of the discrete clamped tubing portion can be by a resistance technique through the clamps or by other techniques such as induction heating or gas radiant heat.

Abstract: A water discharging system for cooling hot rolled steel strip including a header for delivering water to the strip, a water supply system for the header, two fixed overflow pipes arranged to control the volume output of said header: one capable of producing the full flow capacity, and the other a half flow capacity of the water delivered by the header, and a valve for bringing into operation one or the other of said overflow pipes.

Abstract: The continuous steel-sheet heat-treatment plant comprises, in sequence, a zone in which the sheet is heated to a temperature above the recrystallization temperature, a zone in which the sheet is held at this temperature for more than 30 seconds, a rapid cooling zone, an optional overaging zone, and a final cooling zone. The rapid cooling zone has devices for spraying a cooling fluid and a tank containing an aqueous bath at above 75.degree. C.

Abstract: Metal articles are cooled continuously by means of a conical jet of liquid injected into a jet of gas projected at low pressure and high speed onto the articles. The injection is carried out in such a way that particles of liquid are distributed throughout the jet, thus forming a mist which is projected onto the articles. Variable high coefficients of heat exchange are obtained.

Abstract: A vertical continuous annealing furnace has two furnace covers vertically spaced away from each other. Each furnace cover is laterally slidable with respect to the furnace proper and has two long narrow openings through which strip is passed. There is a relatively small pre-chamber between the first furnace cover above and the second furnace cover below. The space below the second furnace cover constitutes a heating chamber. A partition extends from the undersurface of the second furnace cover to near the bottom of the furnace, dividing the heating chamber into a heating zone and a soaking zone. In charging and discharging the strip, the two furnace covers are alternately opened and closed, thereby keeping the heating chamber out of exposure to the outside air.

Abstract: A roller apparatus is disclosed for use in a steel sheet transporting device including a table, a plurality of rolls upon which the steel sheet is transported, and water spray nozzels for cooling the rolls and the steel sheet. The roller apparatus including a plurality of helically arranged grooves for tracking the steel sheet to keep it centered as it passes over the transporting device, and for maintaining a controlled and even film of water over said rolls to cool the rolls and steel sheet while preventing the sheet from hydroplaning.

Abstract: Cooling water is sprayed under a predetermined pressure range and at a predetermined discharge rate over the both surfaces of a sheet to be treated which is reciprocated lengthwise at such a velocity that the product of the reciprocating velocity and thickness of the sheet may be maintained within a predetermined range. The spraying direction of each spray nozzle is individually controlled so that any water remaining over the surface of the sheet may be expelled out. The method and apparatus is especially adapted for use in the normalizing process and in the process for cooling hot-rolled sheet steel.

Abstract: The invention relates to an apparatus for spraying a coolant on steel slabs, comprising spraying nozzles preceded by a mixing chamber with separate feed lines for the propellant and the coolant, the nozzle discharges being designed in such a manner that the mixture of propellant and coolant impinges in the form of wide fans, at an acute angle and in opposite directions on the slab surface, in that the nozzle discharges start from a common nozzle housing into which issues the mixing chamber, the coolant connector to the mixing chamber consisting of an exchangeable inset tube projecting into the mixing chamber, in particular as regards slab-format castings obtained from a continuous casting mold, where the particular nozzles located in the gap between two adjoining guide rollers for the cast slab are directed parallel to the axes of the guide rollers and the nozzle housing is mounted between the plane of the guide roller axes and the slab surface.

Abstract: Method and apparatus for cooling a steel strip in a continuous annealing line, which has a first cooling step in which the steel strip immediately after an overageing treatment is cooled from the overageing temperature to a temperature in the range of from about 95.degree. C. to 60.degree. C., a temperature which prevents a surface oxidation but allows self-drying of the strip, in a protective atmosphere using a liquid coolant; and a second cooling step in which the steel strip is cooled to a temperature suitable for a subsequent temper rolling using liquid coolant at a temperature no higher than 40.degree. C.

Abstract: A plate quenching apparatus is described as having a horizontally elongated chamber in which a plurality of rows of metal, tire-like rollers are used to support an element, such as a number number of metal plates, as the element moves along a horizontal pathway between opposing rows of nozzles above and below the pathway. Unfortunately, the metal rollers create wakes when large quantities of quenching liquid are used. These wakes literally surround tear-shaped areas immediately downstream the rollers and prevent adequate amounts of quenching liquid from contacting the element in these areas, especially at the beginning of the quenching process wherein it is critical to uniformly contact the element with quenching material. A plurality of nozzles are specially positioned between adjacent rows of the metal rollers to break up the wakes and insure that the sheet of metal is uniformly contacted with quenching liquid to prevent the element from becoming buckled, warped, or twisted during the quenching operation.

Abstract: A metal product, such as a steel strip or a mill roll, is cooled by spraying a coolant towards a surface of the product travelling along a given path, by means of cooling apparatus comprising two hollow caissons arranged one inside the other and rigidly connected together to constitute a unit. The caissons cool the strip contained within a tunnel. The method is applied to the product surface and extends across the path of the product surface. Each caisson has a plurality of holes in a wall which is to face the product surface, each hole of the outer caisson being paired with a coaxially aligned hole of the inner caisson. A coolant sprayer is fixed in each pair of holes. Preferably, the sprayers are supplied with air from the inner caisson and water from the outer caisson, the water being atomized by the air. The path containing the prouduct is enclosed within a tunnel wherein ends of the tunnel are enclosed by continuous curtains of water which contact the product and effectively seal the ends of the tunnel.

Abstract: Continuously cooling a rolled metal product emerging from the last stand of a rolling mill by spraying a liquid coolant through at least one outlet orifice of at least one hollow housing onto a rolled product vertically downwardly in the form of a compact jet of liquid which does not include any gaseous constituents and all the molecules of which are at the same speed in a given cross-section transverse to the direction of the jet.

Abstract: An apparatus for continuously producing a high strength dual-phase steel strip or sheet having a chemical composition which produces a dual-phase structure composed of ferrite grains and a low temperature transformed phase when rapidly cooled from the (.alpha.+.gamma.) temperature range or from the .gamma. temperature range. The apparatus has a continuous heat treatment furnace in which the strip moves vertically and which is composed of a heating zone, a soaking zone and a cooling zone, and conventional equipment associated therewith. The cooling zone has an upper hearth roll group, a lower hearth roll group and cooling equipment for cooling the strip at a rate in the range between 1.degree. and 300.degree. C./sec. for retaining the austenite in the steel of the strip.

Abstract: A process for reducing pellets containing metal oxides, such as chrome oxide, iron oxide, zinc oxide, etc. with the contained carbon to metallized pellets in a rotary kiln, characterized by carrying out the reduction while blowing air or spraying water into the portion near the charge end of the kiln in order to prevent too rapid heating of the raw pellets is disclosed.

Abstract: Ambient water and steam in a predetermined ratio are delivered into the entrance of a venturi chamber in a fluid accelerator. The steam condenses and in so doing elevates the water temperature significantly. The heated water passes through a venturi throat and then has its pressure elevated considerably above the pressure of the incoming steam prior to discharging from the accelerator into valved piping leading to cleaning spray headers on opposite sides of the moving metal strip. High pressure, high temperature water cleaning sprays are directed through header nozzles onto the strip to thoroughly clean its entire surfaces. Venturi vacuum is utilized whenever desired to draw a cleaning additive into the system where such additive is entrained in the water stream. Simplicity and economy are achieved in a highly efficient cleaning system.

Abstract: Apparatus and methods for hot rolling and treating rod first by depositing the rod in spread-out ring form on a moving conveyor, then gathering it into a relatively loose somewhat offset bundle and thereafter subjecting it to batch treatments among which are conventional annealing, and/or coating and baking as well as new forms of annealing not heretofor practiced.

Abstract: A steel wire directly from the rolling mill is formed into a horizontally advancing helix having a succession of upstanding turns. This helix is fed into a horizontally opening end of an elbow and a roller at the short side of the elbow deflects the helix so that it exits from the downwardly opening outlet end of the elbow. An upright cooling tube is provided immediately at this downstream end and has a multiplicity of throughgoing holes each aligned with a respective nozzle for spraying of liquid on the descending coil so as rapidly to cool it and to transform at least the surface of it into martinsite. At the lower end of the tube the cooled coil, at a temperature of 500.degree. C.-600.degree. C. as compared with the starting temperature of 750.degree. C., is carried horizontally away by a conveyor.

Abstract: Rolled material leaving a rolling mill is cooled by passing it through a series of guide tubes. A pre-mixed mixture of air and water is injected into each of the tubes by nozzles facing in the direction in which the wire passes, and the wire is cooled by the mixture. The water can be removed at the downstream end of the apparatus by a nozzle facing in the opposite direction to that in which the wire travels.

Abstract: An apparatus for producing a continuous curtain of cooling liquid to cool a hot metal workpiece issuing from a rolling mill. A header tank with an elongated slot formed lengthwise along its underside is provided. An elongated nozzle, located in the header has an outlet extending from the slot. Both the inlet and outlet of the nozzle are generally rectangular in form but differ considerably in cross-section. An insert divides the nozzle into several passageways.

Abstract: A cooling arrangement, especially but not exclusively suited for cooling rolled stock such as wires and bars, has two end members provided with axially aligned passages through which a workpiece can travel. The end members are connected by an annularly arranged series of bars between which spaces are left free so that cooling fluid admitted into contact with the workpiece can rapidly flow off again. The space surrounded by the bars converges in the direction of travel of the workpiece. Upstream of one end member is provided a fluid admitting element formed with a workpiece guide passage which is divergent-convergent as considered in the travel direction of the workpiece.

Abstract: A cooling arrangement, especially but not exclusively suited for cooling rolled stock such as wires and bars, has two end members provided with axially aligned passages through which a workpiece can travel. The end members are connected by an annularly arranged series of bars between which spaces are left free so that cooling fluid admitted into contact with the workpiece can rapidly flow off again. The space surrounded by the bars converges in the direction of travel of the workpiece.

Abstract: At the outlet of the finishing stand of a rolling mill, a cooling apparatus is arranged to surface quench only the outer layer of the flat face of a steel section by a cooling fluid. The cooling conditions are adjusted so that, at the outlet of the cooling zone, the unquenched parts of the section are at a temperature still sufficiently high to temper the quenched face, and so that the austenite is transformed into ferrite and carbides in the unquenched parts of the section.

Abstract: In continuous induction heat treatment of an elongated metal member, additional local induction heating is applied to an end portion or portions of the metal member, thereby to obtain uniform induction heating temperature distribution over the whole length of the metal member. The additional local heating or preheating the end portion of the metal member is performed by the use of a preliminary induction heating coil which is maintained in predetermined relative relationship with the metal member for a predetermined period of time.

Abstract: An apparatus for quenching a heated metal plate moving and restrained in a plane has upper and lower rolls which engage the top and bottom surfaces of the plate. Jets of quench fluid are located between the rolls and direct quench fluid onto the top and bottom surfaces of the plate in the direction of travel of the plate. A tank member is positioned underneath and surrounding the bottom rolls for maintaining the level of quenching fluid so that the plate conveyed on the lower rolls will have its bottom surface continuously swept with high velocity turbulent fluid.