US3889507A

US3889507A - Apparatus for cooling a steel member while being rolled on a continuous hot-rolling mill

Info

Publication number: US3889507A
Application number: US416310A
Authority: US
Inventors: Helmut Kranenberg; Michael Sawitz
Original assignee: Bethlehem Steel Corp
Current assignee: Bethlehem Steel Corp
Priority date: 1973-11-15
Filing date: 1973-11-15
Publication date: 1975-06-17
Anticipated expiration: 1992-06-17
Also published as: NL7414954A; SE414590B; JPS5435873B2; ZA747328B; IT1023240B; JPS5080254A; LU71287A1; FR2251385A1; DE2453742A1; SE7414293L; BE822243A; CA1021969A; FR2251385B1; GB1485020A

Abstract

A spray unit positioned between roll stands in the path of a steel workpiece advancing in a predetermined substantially horizontal pass line in a continuous hot-rolling mill, includes a pair or spaced spray chambers longitudinally aligned in tandem. The steel workpiece passes through a spray section in each of the spray chambers. As the steel workpiece passes through the spray sections, water is sprayed by high pressure nozzles onto the entire surface of the steel workpiece to reduce the temperature thereof. Guard means are provided to prevent damage to the high pressure nozzles. The steel workpiece is aligned axially in the spray chambers by positioning means. The sprayed water is rapidly removed from the spray sections to prevent the formation of a water bath in the spray chambers.

Description

United States Patent Kranenberg et al.

APPARATUS FOR COOLING A STEEL MEMBER WHILE BEING ROLLED ON A CONTINUOUS HOT-ROLLING MILL Inventors: Helmut Kranenberg; Michael Sawitz, both of Bethlehem, Pa.

Assignee: Bethlehem Steel Corporation,

Bethlehem, Pa.

Filed: Nov. 15, 1973 Appl. N0.: 416,310

[52] US. Cl 72/201; 266/65 [51] Int. Cl B2lb 45/02 [58] Field of Search 72/200, 201, 202, 236;

[56] References Cited UNITED STATES PATENTS 1,931,912 10/1933 Whitzel U 72/201 2,067,514 1/1937 Trinks 1. 72/202 3,036,825 5/1962 Eisenmenger 266/4 S 3,671,028 6/1972 Hemsath 266/6 S 3,738,629 6/1973 Coleman 266/6 S I ll! 3,766,763 10/1973 Cofer et al 72/201 Primary Examiner-C. W. Lanham Assistant Examiner-E. M. Combs Attorney, Agent, or Firm-loseph J, OKeefe; Charles A. Wilkinson; John S. Simitz 5 7] ABSTRACT A spray unit positioned between roll stands in the path of a steel workpiece advancing in a predetermined substantially horizontal pass line in a continuous hotrolling mill, includes a pair or spaced spray chambers longitudinally aligned in tandem. The steel workpiece passes through a spray section in each of the spray chambers. As the steel workpiece passes through the spray sections, water is sprayed by high pressure nozzles onto the entire surface of the steel workpiece to reduce the temperature thereof. Guard means are provided to prevent damage to the high pressure nozzles. The steel workpiece is aligned axially in the spray chambers by positioning means. The sprayed water is rapidly removed from the spray sections to prevent the formation of a water bath in the spray chambers.

8 Claims, 6 Drawing Figures PATENTEDJUN 17 1975 3.8 89 5O 7 SHEET 3 APPARATUS FOR COOLING A STEEL MEMBER WHILE BEING ROLLED ON A CONTINUOUS HOT-ROLLING MILL BACKGROUND OF THE INVENTION This invention is directed to apparatus for spraying water or other coolant onto the surface of a steel workpiece while the workpiece is being hot-rolled in a continuous hot rolling mill to control the finishing temperature of the steel workpiece off-the-mill. The apparatus of the invention more particularly comprises a spray unit having a pair of spray chambers wherein spray means are used to spray water onto the surface of the steel workpiece as it passes through said spray chambers.

Steel products, such as bars and rods, are produced by hot rolling steel billets in a continuous hot-rolling mill, for example, a bar mill, a rod mill or the like. The hot rolled steel generally is finish rolled at temperatures of between about 1,950 to 2,l F. and is then aircooled to ambient temperature. During air-cooling a non-uniform, thick, coarse and sometimes blustery scale forms on the surface of the steel and the steel does not attain uniform metallurgical characteristics. All prior art processes to control the scale formation and to produce steel having uniform metallurgical characteristics have generally involved apparatus to treat the steel after it has been finish rolled but prior to air-cooling, as exemplified, for example, in U.S. Pat. No. 3,735,966 issued May 29, I973 to Bernd Hoffmann and entitled Method for Heat Treating Steel Wire Rod. Hot-rolled rod is passed in accordance with the disclosure of this patent through alternate quenching and heat compensating zones to cool the surface temperature of the rod to below about 400 C. (752 F.) subsequent to finish rolling and prior to coiling in flat overlapping wraps on a conveyor. The apparatus is comprised of water cooling units and air cooling units. The length of the water cooling units becomes shorter and the length of the air cooling units becomes longer in the direction of travel of the finished rod according to a logarithmic relationship.

U.S. Pat. No. 1,988,l92 issued Apr. 16, I935 to A. B. Haswell entitled Means for Guiding and Cooling Rolled Metal is directed to apparatus for guiding and cooling hot-rolled stock such as rounds, squares, strip and similar sections as the hot-rolled stock comes from the rolls of a rolling mill in a highly heated state. The apparatus comprises water boxes spaced above and below a passage for the steel. Steel members close the sides of the passage. The water-boxes are much larger than the passage to thereby prevent heating of the cooling water in the water-boxes. The water is fed into the passage from the water boxes by ports provided therein. The amount of water in the passage is sufficient to form a bath through which the steel passes.

Unfortunately, when steel at elevated temperatures comes into contact with water, a steam blanket forms around the steel. The steam blanket insulates the steel, preventing contact between water and steel. The cooling effect of the water is retarded if not altogether blocked. Passing the steel through a water bath is not an effective way to reduce the temperature of the steel.

It is the primary object of this invention to provide apparatus positioned between roll stands for spraying water onto the entire surface of a steel workpiece as it is being advanced in a continuous hot-rolling mill.

SUMMARY OF THE INVENTION The apparatus of the invention is a spray unit which includes a pair of spaced spray chambers enclosing a portion of the pass line in a continuous hot-rolling mill and spray means in said spray chambers to spray a coolant onto the entire surface of a steel workpiece being hot-rolled. Guard means mounted on support means in said spray chambers protects the spray means from contact with the steel workpiece. Means for positioning the steel workpiece axially in said spray chambers is provided at the middle portion and exit end of the spray unit. The spray unit is mounted between the roll stands of a continuous hot-rolling mill.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic plan view of the spray apparatus between roll stands in a continuous hot-rolling mill.

FIG. 2 is a view in elevation of the apparatus of the invention.

FIG. 3 is a cross-sectional view along 33 of FIG. 2.

FIG. 4 is a cross-sectional view along 44 of FIG. 2.

FIG. 5 is a longitudinal sectional view of the apparatus shown in FIG. 2.

FIG. 6 is a cross-sectional view along 6-6 in FIG. 5 of a control box in the spray apparatus.

PREFERRED EMBODIMENT OF THE INVENTION A steel workpiece which is being hot-rolled on a continuous hot-rolling mill, such as a bar mill, rod mill and the like, is cooled during hot-rolling by passing the steel workpiece through at least one spray unit mounted between roll stands in line with the predetermined substantially horizontal pass line defined by the roll passes in the roll stands of the mill. Water is sprayed onto the entire surface of the steel workpiece to cool the surface of the steel workpiece during hot rolling. The as-rolled product off-the-mill has an integrated mean temperature of not more than about l,750 F. A diagrammatic plan view of a continuous hot-rolling mill and auxiliary equipment with spray units in position between roll stands of the mill is shown in FIG. 1.

Turning now to FIG. 1, the steel workpiece is heated to a rolling temperature within the range of about 1,950 to about 2,100 F. in a furnace 10 generally used for this purpose. The steel member is discharged from furnace l0 and is hot-rolled to finish size in mill 1] which comprises a roughing train 12 having roll stands l3, l4, 15, 16, l7, l8, l9 and 20; an intermediate train 21 having roll stands 22, 23, 24, 25, 26 and 27; finishing train 28 having roll stands 29, 30, 31 and 32; a run-out table 33', a coiling station 34 having

coilers

35, 36, 37 and 38 and a cooling bed 39. A flying shear 40 is provided between the roughing train 12 and intermediate train 21.

Repeaters

41 and 42 in the intermediate train 21 and repeater 43 between the intermediate train 21 and finishing train 28 are provided to loop the steel workpiece during hot-rolling. Troughs 44,45, 46 and 47 in the intermediate train 21 and trough 48 between repeater 43 and the finishing train 28 provide support for the steel workpiece as it passes through the mill 11. A flying shear 49 after the finishing train 28 cuts the steel to length when required. Spray units 50 amd 51 in the intermediate train 21 and spray units 52 and 53 between the intermediate train 21 and finishing train 28 are used to spray water onto the surface of the steel workpiece as it is being hot-rolled to control the temperature of the steel workpiece.

In operation, the steel workpiece is passed from the furnace to the mill 11 and passes progressively continuously through the roll stands 13, l4, 15, 16, 17, 18, 19 and 20 in the roughing train 12. The temperature of the steel workpiece is observed by use of radiation-type pyrometer RP1 between roll stands 13 and 14. A short portion of the front end of the steel workpiece is cropped by flying shear 40 as the steel workpieces passes between roll stand 20 and the first roll stand 22 of the intermediate train 21. The steel workpiece continues through the roll stands 22, 23, 24, 25, 26 and 27 of the intermediate train 21. Roll stands 24 and 25 appear as dummy stands in FIG. 1, that is, there are no rolls in the roll stands and hence the steel workpiece is not reduced in cross-sectional area as it passes through these stands. However, dependent upon the size of steel workpiece being hot-rolled and the desired finish size, the stands can be equipped with matches rolls to also reduce the cross-sectional area of the steel workpiece during its passage through these stands. The temperature of the steel workpiece is taken by a radiation-type pyrometer, RP-2, as it passes between roll stands 24 and 25. As the steel workpiece passes through the intermediate train 21, it is looped l80 by

repeaters

41 and 42. Of course, the steel workpiece can be hotrolled in an in-line continuous hot-rolling mill which does not require the use of repeaters. As the steel work piece passes through the intermediate train 21, the steel workpiece passes through

spray units

50 and 51 located between roll stands 25 and 26. Water is sprayed onto the surface of the steel workpiece as it passes through the

spray units

50 and 51. The flow of water in each spray unit in the mill is controlled to start after the leading end of the steel workpiece has passed through the spray unit to prevent hardening of the leading end of the steel workpiece and thereby prevent marring or spalling of the surface of the work rolls in the roll stands which could occur as the steel workpiece enters the roll passes in the roll stands. The steel workpiece is supported by trough 44 as it passes between first spray unit 50 and second spray unit 51. The steel workpiece is looped 180 in repeater 41 and is supported by trough 45 as it passes to roll stand 26. Trough 46 supports the steel workpiece as it passes to repeater 42 where the steel workpiece is again looped 180 and is passed to roll stand 27 which is the last roll stand in the intermediate train 21. The temperature of the steel workpiece is again taken by a third radiation-type pyrometer, RP-3, prior to rolling in roll stand 27. After the steel workpiece passes from the intermediate train 21 it passes through spray units 52 and 53 arranged in tandem. The steel workpiece is again looped 180 in repeater 43, passes through trough 48 and is rolled to a desired finish size in roll stands 29, 30, 31 and 32 of the finishing train 28. A flying shear 49 after roll stand 32 cuts the steel workpiece to the desired length. The temperature of the steel workpiece is again taken by a radiation-type pyrometer, RP4, as it leaves the last roll stand 32 in the finishing train 28. If it is desired to coil the steel workpiece, it is passed to one of

coilers

35, 36, 37, 38 in coiling station 34. If straight bars are being produced, the steel workpiece is passed to the run-out table 33 and then to cooling bed 39. In either case, the steel workpiece is air-cooled to ambient temperature after finish rolling.

We have found that by hot-rolling the steel workpiece as described above, the temperature of the surface of the steel workpiece off-the-mill is controlled to about 1,740 F. for finished bars and rods having a diameter of one-half of an inch, and preferably not more than about l,700 F. for finished bars and rods having large diameters. The integrated mean temperature of the steel workpiece off-the-mill is not higher than about l.750 F. A steel workpiece hot-rolled in the conventional manner, that is, wherein the steel workpiece is not water sprayed during rolling, has a surface temperature of between about [900 and 2,100 F. and an integrated mean temperature of about l,950 F. or higher.

Since

spray units

50, 51, 52 and 53 are identical. we will describe only spray unit 50. Referring now to FIG. 2, the spray unit includes a pair of spray chambers 54, 55 aligned longitudinally in tandem in line with the predetermined substantially horizontal pass line of the steel workpiece as it passes through the mill. The spray unit 50 has an entry end 56 and an exit end 57. The entire spray unit 50 is supported by

stands

58, 59 which can be of any suitable material. such as reinforced concrete, steel structural framework and the like. Spray chambers 54 and 55 are substantially the same. Therefore only spray chamber 54 will be described in detail. Identical numbers will be used to identify identical parts of each spray chamber. Spray chamber 54 has an entry end 56, which is also the entry end 56 of the spray unit 50, and an exit end 60. The spray chamber 54 comprises a cover 61 shown contiguous with a bottom portion 62 as described hereinafter and shoen in FIG. 3. The ends 56 and 60 are made watertight by welding

metallic plates

56a and 56b, 60a and 60b to the cover 61 and bottom portion 62, respectively. The cover 61 can be pivotally lifted manually from the bottom portion 62 by means of handles 63. An elongated water collecting and disposal trough 64 is fastened to bottom portion 62 and extends substantially the length of the spray unit 50. A plurality of outlet pipes 65 extend downwardly from the bottom of the trough 64 and communicate therewith by means of ports (not shown), which allow the rapid removal of water to waste or to storage. The cover 61 and bottom portion 62 are provided with a plurality of inlet pipes, 66, 67, and 68, 69 respectively whereby water under pressure, for example, about 25 pounds per square inch gage to about 60 pounds per square inch gage, is pumped therein. Although water under a gage pressure of 25 pounds per square inch can be used to advantage, we prefer to use water having a gage pressure of 35 pounds per square inch. A hell or guide cone assembly 70 comprises a base plate 70a integral with a guide cone 70b. The guide cone assembly 70 is attached to the end plate 56b, for example, by bolt and nut assemblies (not shown) and guides the steel workpiece axially into the spray chamber 54. The spray chambers 54 and 55 are spaced a distance apart. A first control box 71 is provided in the space between spray chambers 54 and 55 to provide means interiorly (hereinafter described) for positioning; the steel workpiece axially in conjunction with a second control box 77 in the spray unit 50. The control box 81 has a box-like exterior housing 72 having end plates 72a and side plates 72b. A control arm 73 is rotatably attached to a shaft 74. A control handle 730 on control arm 73 provides means to rotate control arm 73 through A semicircular locking hub 73b positioned between the control arm 73 and side plate 72b provides means for locking a positioning funnel (shown in FIG. 3 and identified as 76) in a desired position interiorly in the control box 71. A guard cone 720 is provided atop the housing 72 to prevent the steel workpiece from passing upwardly and straying from the pass line of the mill when passing from spray chamber 54 to spray chamber 55. A water inlet pipe 72d atop the guard cone 72c allows water to be passed downwardly through the control box 71 to prevent over-heating of the metallic parts interiorly the control box 71. The control box 71 is secured to end

plates

60b and 56b by any means, for example, welding. Control box 77 is attached by any means, for example, welding, to the end plate 60b.

Turning now to FIG. 3, which is a cross-sectional view of spray chamber 54, along line 3-3 in FIG. 2, the cover 61 is an elongated box-like watertight header, fabricated in the shape shown from two

metallic plates

78 and 79. The two

metallic plates

78 and 79 are welded together to form the watertight structure shown. Water W is pumpled into header 61 by means of two

inlet pipes

66 and 67. Plate 79 is provided with ports (not shown) wherein couplings 80a are fixedly attached. High pressure nozzles 80 are threaded into the couplings and communicate with the interior of header 61. The high pressure nozzles 80 spray water in a fan-shaped jet. An angle 70 defines the extent of the jet. The fan-shaped jet defines a substantially steaight line on the surface of the steel workpiece which is impinged by the jet. The fan-shaped water jet is formed by a generally oval opening in each nozzle 80. The nozzles 80 in the spray chambers 54, 55 are positioned in the header in a manner such that the fanshaped jet is at an angle of 20 to the axis of the steel workpiece. By positioning the nozzles 80 in this manner the substantially straight line impinged on the surface is made wider and a larger surface area of the steel workpiece is impinged by the fan-shaped jet than if the oval opening is positioned parallel to the axis of the steel workpiece. In the latter position, non-uniform cooling of the surface of the steel workpiece would occur. Two horizontal lips 78a and 78b are formed in plate 78.

A downwardly open yoke 81 is fastened to the header 61 by fastening means, for example, a sleeve and bolt combination 82, extending downwardly through two ports (not shown) in the header 61. A plurality of the yokes 81 spaced a distance apart are provided along the length of the chamber 54. A plurality of spaced buard bars 83, generally rectangular in cross-section, are attached, for example, by welding, to each of the yokes 81 and extend longitudinally and substantially the length of the header 61. It must be understood that the yokes 81 can be other geometric shapes, such as a semi-circle, other polygonal shapes and the like. Likewise, the guard bars 83 can be of any shape in crosssection, for example, square, rectangular, triangular, and the like. The guard bars 83 protect the high pressure nozzles 80 from damage by the passing steel workpiece S particularly in the case of a cobble or by the leading edge (not shown) of the steel workpiece S as it passes through the spray chamber 54.

The bottom portion 62 of the spray chamber 54 comprises two elongated box-

like headers

84 and 85 which are fabricated in the shapes shown and are watertight. The

headers

84, 85 are mirror images of each other and are in longitudinally spaced parallel relationship to each other. The space between and defined by the headers 84, is an elongated slot 86 extending the length of the spray chamber 54. Since the

headers

84, 85 are mirror images of each other, only header 84 will be described, and similar parts of the

headers

84, 85 will be identified with the same numerals. Header 84 is fabricated from two

metallic plates

87, 88 in the shape shown. Header 84 can best be described as generally being an open L in shape. The open L is formed by an outer vertical leg 87a and a horizontal base 87b formed by plate 87 and an inner generally horizontal lip 880, a vertical leg 88b perpendicular to the lip 88a, and a generally sloping lower leg 88c extending from leg 88b to a short vertical leg 88d. The lip 88a is parallel to base 87b and is welded to the upper edge of leg 87a. The leg 88d is parallel to leg 87 a and is welded to the base 87 b to make a watertight container. End plates (not shown) are welded to each end of the header 84 to make a watertight container. The horizontal lip 88a provides a surface 88c which is contiguous with lip 780 when the cover 61 is placed atop the bottom portion 62 to form a closure through which the steel workpiece S passes. When the cover 61 is closed atop bottom portion 62 a spray section A is formed which encloses a portion of the substantially horizontal pass line of the mill. The vertical leg 88b and the sloping leg 880 are provided with ports (not shown) wherein couplings 800 are fixedly attached. High pressure nozzles 80 are threaded into the couplings and communicate with the interior of the header 84. Water having a gage pressure of betwen about 25 pounds per square inch, but preferably 35 pounds per square inch, to 60 pounds per square inch is pumped into the header 84 through two

inlet pipes

68, 69 extending horizontally inwardly through ports (not shown) in the vertical leg 870.

An upwardly open yoke 89 having bosses 90 and 91 is fastened by means, for example, bolts 92, to supports 93 and 94 welded to the base 87b and extending upwardly into the bottom portion 62. The yoke 89 can have other geometric shapes, for example, any type of polygon, circular and the like. A plurality of elongated spaced guard bars 83 are attached, for example, by welding, to a plurality of yokes 89 spaced longitudinally in the spray chamber 54. The guard bars 83 extend the length of the spray chamber 54. While shown as being generally rectangular, the guard bars 83 can be any shape, for example, square, triangle, and the like.

The collecting and disposal means 64 is an elongated generally U-shaped trough fabriacated from metallic sheet 95 in the shape shown. The trough is fastened to the spray unit 50 by means, for example, bolt and nut assemblies 96 passing through

lips

96a and 96b attached to the bottom portion 62, for example, by welding. Water is discharged from the trough 64 through outlet pipe 65 which communicates with the trough 64 through a port (not shown).

A vertically movable positioning funnel (shown in FIG. 5 and identified as 76) positions the steel workpiece S axially in the spray unit 50. The positioning funnel 76 in conjunction with a second positioning funnel 76' (FIG. 5) at the exit end 57 supports the steel workpiece S as it passes through the spray unit 50. The guide cone assembly 70 in FIG. 2 guides the steel workpiece S axially into the spray unit 50 but does not support the steel workpiece S as it passes through the mill.

The header 61 (shown in the open position in phantom) is pivotally attached to the bottom portion 62 by a hinge assembly 98 comprising a pair of

metallic brackets

98a and 98b which are fastened by suitable means to the back walls 610 and 84a of the header 61 and header 84, respectively. Each of the

brackets

98a and 98b is provided with a hub 98c and 98d, respectively. The hubs 98c and 98d have an aperture 98e therein. When assembled, the hubs 98c and 98d overlap so that the apertures 98c are aligned. A smooth bearing type rod 98f is inserted into the apertures 98e so as to hold the

brackets

98a and 98b together in pivoted relationship. Removable L-shaped pins 98g are inserted into passages 98/1 on either side of the

brackets

98a and 98b in the rod 98f to prevent accidental removal of rod 98f. Only one L-shaped pin and aperture are shown.

When the header 61 is contiguous with the bottom portion 62, that is, lips 78a and 78b are contiguous with lips 88, a generally cylindrical spray section A is formed wherein the steel workpiece S passes through the spray unit and is sprayed with water. The high pressure nozzles 80 form a generally annular configuration and are spaced about 60 apart.

The spray chamber 55 of the spray unit 50 is shown in FIG. 4 which is a cross-sectional view taken along the line 44 of FIG. 2. The header 61' is fabriacted from

metallic plates

99 and 100 to form a header 61' in the shape shown. Metallic plate 99 is generally U- shaped having a horizontal base 99a and two downwardly extending legs 99b and 99c. Metallic plate 100 has a horizontal base section 1000, two downwardly and outwardly extending legs lb and 100a and horizontal arms 100d and 100e extending horizontally outwardly from the legs 10012 and 100e, respectively. The extremities of the arms 100d and 100s are welded to the extremities of the legs 99b and 99c respectively to form a watertight header 61'. A plurality of ports (not shown) are provided in the base 100a and the legs l00b and l00c wherein couplings 80a are fixedly attached. High pressure nozzles 80' are threaded into the couplings 80a and communicate with the interior of the header 61. Water W having a gage pressure of between 25 pounds per square inch, and preferably 35 pounds per square inch, to about 60 pounds per square inch is pumped into the header 6] by conventional pumping equipment (not shown) through inlet pipes 66' and 67'. The water is sprayed onto the surface of steel workpiece S passing through spray section A of the spray chamber 55 which is in line with spray section A in spray chamber 54. The high pressure nozzles 80' form a similar spray as described previously. The high pressure nozzles 80' are annularly positioned 60' apart. Aligned ports (not shown) are provided in the base 990 and 100a whereby fastening means 101, for example, a sleeve and bolt assembly, are used to support a downwardly open yoke 102 of the shape shown. A plurality of guard bars 83' are fixedly attached to the yoke 102, for example by welding. The guard bars 83' prevent damage to the high pressure nozzles 80' by cobbles or from the leading edge of the steel workpiece S as it passes through the spray chamber 55. As noted previously, the shape of the guard bars 83' is generally rectangular, but any shape can bee used.

The bottom portion 62' comprises two headers 103 and 104 fabricated from

metallic plates

105, 106 and 107, 108, respectively, in the shapes shown. Header 103 can be described as having an open elongated L shape. The open L shape is formed by an outer vertical leg 105a and a horizontal base [05b perpendicular to leg 105a, a short vertical leg 105C formed from plate 105 and a horizontal lip 106a, a short vertical leg 106b, a sloping portion 1060 and a horizontal base 106d formed from plate 106. The extremity of lip 1060 is welded to the upper surface of leg 105a and the horizontal base 106d is welded to vertical leg 105c to form a watertight closure. End plates (not shown) are welded to each end of the header 103 to form a watertight container. Sloping portion 106C and horizontal base 106d are provided with ports (not shown) whereby couplings 800' are fixedly attached. High pressure nozzles 80' are threaded into the couplings 80a and communicate with the interior of the header 103. Header 104 is formed by joining two

metallic plates

107 and 108 which have two generally vertical legs 107a and 1080 and two horizontal bases l07b and 108b. Vertical leg 1070 has a sloping section 1071: provided with a port (not shown) wherein a coupling 80a is fixedly attached. A high pressure nozzle 80 is threaded into the coupling 80a and communicates with the interior of header 104. Vertical leg 107a is welded to horizontal base 108b, and horizontal base 107b is welded to vertical leg 108a to form a watertight closure. End plates (not shown) are welded to either end of header 104 to make a watertight container. Water under a gage pressure of 25 pounds per square inch, and preferably 35 pounds per square inch, to 60 pounds per square inch is introduced into header 103 through inlet pipes 68' and 69' and into header 104 through inlet pipes 68' and 69'.

An upwardly opening yoke 109 of the shape shown is attached to the bottom portion 62' by fastener means 110, for example, a sleeve and bolt assembly, extending through ports (not shown) provided in headers [03 and 104, respectively. A plurality of spaced guard bars 83' are fixedly attached to the yoke 109.

The headers 103 and 104 are spaced a distance apart and form an elongated longitudinal slot 86 whereby the watei" after being sprayed onto the steel workpiece S can freely pass out of the spray section A, formed when header 61' is contiguous with bottom portion 62', to the collecting and disposal trough 64 which is attached to the bottom portion 62' of the spray unit 50 by fastening means 96' and 96' passing through

lips

96a and 96b. The water passes from trough 64 to waste by means of outlet pipe 65.

The header 6] is pivotally attached to the bottom portion 62' by identical hinge assembly 98' used in spray chamber 54 and which was previously described.

When the header 61' is in the operating position the high pressure nozzles 80' form a generally annular configuration and are spaced about 60 apart. The high pressure nozzles 80' are not aligned with the high pressure nozzles 80 in the spray chamber 54 but are rotated about 30 therefrom to thereby give a simulated rotation effect to the steel workpiece S as it passes through the spray unit 50 and to assure that the entire surface of the steel workpiece S is sprayed with water. The use of two spray chambers in tandem provides a thorough force cooling of the entire surface of the workpiece.

FIG. 5 is a longitudinal sectional view of the paired spaced spray chambers 54 and 55 longitudinally in tandem of the invention. The spray chamber 54 is provided with a guide cone assemply as previously described at the entry end 56 of the spray unit 50 to guide the steel workpiece S axially into the spray section A. The steel workpiece S proceeds axially through the spray chamber 54 to a first control box 71 wherein steel workpiece S is guided axially by positioning funnel 76 into spray chamber 55. The steel workpiece S travels axially through spray chamber 55 and leaves at the exit end 57 of the spray unit 50 through a second control box 77. The positioning funnel 76' in the second control box 77 guides the steel workpiece S axially out of the spray unit 50 and keeps the steel workpiece S in the substantially horizontal predetermined pass line of the mill. As the steel workpiece S passes through the spray unit 50, the water is sprayed onto the surface thereof by means of a plurality of high pressure nozzles 80 and 80' which are in a generally annular configuration as shown in FIGS. 3 and 4. The annular configurations are spaced a distance apart and extend the length of each of the spray chambers 54 and S5. A plurality of longitudinally extending guard bars 83 and 83' fixedly attached to

yokes

81, 89 and 102, 109, respectively, to guard the high pressure nozzles 80 and 80' from damage which can occur because of cobbles or from contact with the leading edge of the steel workpiece S as it passes through the spray unit 50. In operation, the nozzles 80 and 80' are not activated until the leading edge of the steel workpiece S has passed through the spray unit 50 to thereby prevent hardening of the leading edge of the steel workpiece. Spraying the leading edge with water would harden the leading edge and damage could occur to the rolls when the leading edge enters the roll pass between the rolls. The collecting and disposal trough 64 described previously and shown in cross-section in FIGS. 3 and 4 extends substantially the length of the spray unit 50.

The

control boxes

71 and 77 are identical. To fully describe the

control boxes

71 and 77 we have shown control box 71 in longitudinal section and control box 77 in a plan view in elevation of the exterior in FIG. 5. Turning now to the control box 77, a control arm 73' is fixedly attached to a longitudinal shaft 74 extending through the control box 77. A control handle 73a is provided on control arm 73' whereby the control arm 73' can be rotated about shaft 74' for a distance of 180. A slot 73c is cut in control arm 73. a generally L-shaped lever 73d is pivotally mounted between two parallel ears 73e welded to control arm 73 so as to pass through the slot 73c. The lever 73d pivots on a short headed pin 73]" which is passed through apertures 73: in the ears 73e. As shown in FIG. 6, a locking pin 73g chained to one of the ears 73e is passed through aperture 73k in the lever 73d and apertures 73: in the ears 73e to lock the lever 73d in place in any of the notches N provided in the hub 73b as described below. A generally semicircular hub 73b having a plurality of predetermined radially disposed notches N is mounted between the housing 72' of the control box 77 and the control arm 73. The notches N are placed so that when control arm 73' is rotated about shaft 74' a positioning funnel 76' interiorly the control box 77 is raised or lowered. The lever 73d can be inserted into one of the notches N to thereby lock the positioning funnel 76' into the proper position so that the steel workpiece S will be positioned axially in the spray unit 50. A coneshaped guard 720 is provided over the control box 77 to prevent the steel workpiece S from passing outwardly from the pass line of the mill as it passes from chamber 54 to spray chamber 55. A water inlet pipe 72d allows water to be passed into the control box 77 to cool the metallic members in the interior of control box 77. The water is collected in a lower collecting box 77a and is discharged therefrom through outlet pipe 77b.

Turning now to FIG. 5 which is a longitudinal sectional view of control box 71, the positioning funnel 76 has a flared semi-conical guiding portion 760 and a horizontal semicylindrical supporting section 76b, and a downwardly depending leg 76c. The leg 760 has three generally parallel open slots 76d, 76:: and 76fextending upwardly a predetermined distance from the bottom surface 763. The positioning funnel 76 is supported on bolts 76h. The positioning funnel 76 can be moved vertically by cam 74b (shown in FIG. 6 and described below) extending through slot 76e.

FIG. 6 is a cross-sectional view of control box 77. The interior metallic parts include the positioning funnel 76 and a U-shaped bracket assembly 11] extending upwardly on either side of the downwardly depending leg 76c supported upon and vertically movable by a rotatable shaft 74. The Ushaped bracket has two parallel upwardly extending legs 112 welded to a horizontal base member 113. A plurality of support legs 114 extend downwardly from the bracket assembly. A pair of outwardly extending arms 115 perpendicular to the legs 112 aid in aligning the positioning funnel 76' in the control box 77. Two nut and bolt assemblies 116 (one is shown) on either side of shaft 74' extending through the legs 112 and downwardly depending leg 76c, support the positioning funnel 76'. The U-shaped bracket assembly gives support to the downwardly depending leg 760' to prevent distortion of the leg 76c during use. The positioning funnel 76' and bracket assembly 111 are vertically movable as a unit. If maintenance is required, positioning funnel 76' can be lifted out of the control box 77 without removing any other part of the apparatus.

The shaft 74' extends through the housing 72' of the control box 77 and is divided into three segments, 74a, 74b and 740. The largest diameter segment 74a provides a bearing surface upon which the shaft can be rotated and gives the strength required to prevent early failure of the shaft. The middle segment 74b is a cam by which the positioning funnel 76' is positioned. The cam 74b by definition is an eccentric. A circle defined by the outer surface of the cam 74b when it is rotated through 360 has the same diameter as the actual diameter of segment 74a. Therefore, the positioning funnel 76', vertically movable on cam 74b, can be raised or lowered a desired distance to position the steel workpiece S axially in the spray unit 50. Segment 74c has the smallest diameter of the shaft, The segment 74c provides two bearing surfaces 74d and 74e for the shaft 74' and also aligns the shaft 74' horizontally and perpendicular to the pass line of the mill.

A pair of

metallic support plates

116 and 117, which extend interiorly the length of the control box 77, are welded to the end plates 72a. Apertures 116a and 1170 of appropriate size are provided in

plates

116 and 117, respectively, to provide bearing surfaces for shaft segments 74c and 740, respectively.

Metallic mounting brackets 118a extending perpendicularly outwardly from the side plates 72!) of the housing 72 are provided whereby the control box 77 can be fastened to the end plate 60b of the spray unit 50 by means such as nut and bolt assemblies (not shown) passed through the apertures 118a and mating apertures (not shown) in the end plate 60b.

While we have described the above apparatus being used to control the temperature of a steel workpiece which is being hot-rolled on a continuous hotrolling mill, it must be understood that the apparatus can also be used to control the temperature of a steel workpiece which is being prepared by thermomechanical means or by ausforming means or by ferritic rolling means.

We claim:

1. In a continuous hot-rolling mill having a plurality of roll stands for advancing a solid steel workpiece in a predetermined substantially horizontal pass line, the improvement comprising:

a. at least one spray unit comprising a pair of spaced coolant spray chambers, aligned longitudinally in tandem, positioned between two of said roll stands in said mill and surrounding a portion of said pass line,

b. a plurality of spray means in each of said spray chambers for spraying water onto the surface of said steel workpiece as said steel workpiece is advancing along said pass line, and

c. elongated guard means in each of said spray cham bers to guard said spray means from contact with said steel workpiece said guard means in each of said spray chambers comprising a plurality of spaced elongated metallic bars generally rectangular in cross section extending longitudinally substantially the length ofeach of said spray chambers, the space between said guard means providing access for spray water from said spray means to impinge on the surface of said advancing steel workpiece.

2. The spray unit of claim 1 wherein said spray means in each of said spray chambers are arranged in linear rows and the rows of said spray means in one of said spray chambers are rotated a predetermined distance about the pass line of the apparatus from the line of said spray means in said other spray chamber.

3. The spray unit of claim 1 wherein said spray means in each of said spray chambers comprise a plurality of high pressure nozzles in annular configuration; a plurality of said annular configurations being spaced a distance apart longitudinally substantially the length of each of said spray chambers, said high pressure nozzles defining a spray section surrounding a portion of said pass line in said mill.

4. The spray unit of claim 1 wherein a first control means is inserted between said pair of spaced spray chambers to position said advancing steel workpiece in a continuous generally horizontal line when it passes from one spray chamber to the other spray chamber and a second control means is provided at said exit end of said spray unit to guide said advancing steel workpiece in said pass line.

5. The spray unit of claim 1 wherein each of said pair of spray chambers comprises a cover, contiguous with a bottom portion and partially attached to said bottom portion, and said cover being pivotally removable verti cally from said bottom portion to expose the interior of said spray chamber.

6. The spray unit of claim 5 wherein the cover of each of said spray chambers is a fabricated elongated box-like header wherein water under a gage pressure of about 25 pounds per square inch to about 60 pounds per square inch can be held prior to spraying onto said surface of said advancing steel workpiece.

7. The spray unit of claim 4 wherein the control means is a control box comprising a metallic cone like cover provided with a water inlet to prevent said ad vancing steel workpiece from leaving said pass line of said mill, a semi-cylindrical funnel-like positioning member having a downwardly extending arm provided with a plurality of downwardly open slots, and a pair of pins mounted on said arm wherein two of said slots are supported in a manner so as to restrict horizontal movement of said guide member but to allow vertical movement thereof, the other of said open slots resting on a cam of a shaft extending through said control means and being supported on a bearing member, said shaft being attached to a control arm provided with a central handle whereby said control arm can be rotated to rotate said cam through a distance of when said control arm is raised to a predetermined position to raise or lower said positioning member to position said steel workpiece in said spray chamber.

8. Apparatus for spraying water onto the surface of a steel workpiece advancing along a predetermined substantially horizontal pass line in a continuous hotrolling mill, to control the temperature of said steel workpiece and produce a product off-the-mill which has an integrated mean temperature of not more than 1,750 E, comprising:

a. a spray unit, having an entry end, a center portion and exit end, positioned to encircle a portion of the pass line, said spray unit comprising:

1. a pair of spaced spray chambers arranged longi tudinally in tandem, each of said spray chambers having a cover contiguous with and partially attached to a bottom portion,

2. spray means inside of each of said covers and said bottom portions in an annular configuration spaced longitudinally the length of each of the spray chambers,

3. transverse support means spaced the length of said spray chambers,

4. guard means fastened to said support means and extending longitudinally the length of said spray chambers,

b. a water collecting and disposal means attached to the bottom of said spray unit, and

c. positioning means at the center section and exit end of said spray unit whereby said steel workpiece is aligned for passage axially through said spray units.

PATENT NO.

DATED INVENTOR(S) I Col.

Col.

Col

Col.

It is certrfred Ural error appears In the ab0ve-|dentifred patent and that said Lelters Patent are hereby corrected as shown below:

2, Abstract, line 4, "or" should read --of-.

l of Background line 22, "blustery" should read -blister"- l, line line line

line

[SEAL] Helmut Kranenberg et a1.

"a generally" should read --A generally-.

UNITED STATES m'n'ar T, OFFICE CERTRFICATE OI" CORR .ECTION June 17, 1975 "shoen" should read --shown--.

"81" should read --7l-.

"betwen" should read --between.

"fabriacted" should read -fabricated--.

"80a" should read --80a'.

"bee" should read -be--.

"assemply" should read --assembly.

(Capital A) Signed and Scaled this sixteenth D3) Of September1975 A ttesr:

RUTH C. MASON ilresting Officer

Claims

1. In a continuous hot-rolling mill having a plurality of roll stands for advancing a solid steel workpiece in a predetermined substantially horizontal pass line, the improvement comprising: a. at least one spray unit comprising a pair of spaced coolant spray chambers, aligned longitudinally in tandem, positioned between two of said roll stands in said mill and surrounding a portion of said pass line, b. a plurality of spray means in each of said spray chambers for spraying water onto the surface of said steel workpiece as said steel workpiece is advancing along said pass line, and c. elongated guard means in each of said spray chambers to guard said spray means from contact with said steel workpiece said guard means in each of said spray chambers comprising a plurality of spaced elongated metallic bars generally rectangular in cross seCtion extending longitudinally substantially the length of each of said spray chambers, the space between said guard means providing access for spray water from said spray means to impinge on the surface of said advancing steel workpiece.

3. transverse support means spaced the length of said spray chambers,

4. guard means fastened to said support means and extending longitudinally the length of said spray chambers, b. a water collecting and disposal means attached to the bottom of said spray unit, and c. positioning means at the center section and exit end of said spray unit whereby said steel workpiece is aligned for passage axially through said spray units.

5. The spray unit of claim 1 wherein each of said pair of spray chambers comprises a cover, contiguous with a bottom portion and partially attached to said bottom portion, and said cover being pivotally removable vertically from said bottom portion to expose the interior of said spray chamber.

7. The spray unit of claim 4 wherein the control means is a control box comprising a metallic cone-like cover provided with a water inlet to prevent said advancing steel workpiece from leaving said pass line of said mill, a semi-cylindrical funnel-like positioning member having a downwardly extending arm provided with a plurality of downwardly open slots, and a pair of pins mounted on said arm wherein two of said slots are supported in a manner so as to restrict horizontal movement of said guide member but to allow vertical movement thereof, the other of said open slots resting on a cam of a shaft extending through said control means and being supported on a bearing member, said shaft being attached to a control arm provided with a central handle whereby said control arm can be rotated to rotate said cam through a distance of 180* when said control arm is raised to a predetermined position to raise or lower said positioning member to position said steel workpiece in said spray chamber.

8. Apparatus for spraying water onto the surface of a steel workpiece advancing along a predetermined substantially horizontal pass line in a continuous hot-rolling mill, to control the temperature of said steel workpiece and produce a product off-the-mill which has an integrated mean temperature of not more than 1,750* F., comprising: a. a spray unit, having an entry end, a center portion and exit end, positioned to encircle a portion of the pass line, said spray unit comprising: