1. Field
Embodiments of the present invention relate generally to the cooling of work rolls in a rolling mill, and are concerned in particular with improving the cooling efficiency of liquid coolants such as water or the like applied to the roll surfaces.
2. Description of Related Art
In a known arrangement, as disclosed for example in U.S. Pat. No. 6,385,989 (Cassidy), a coolant delivery device partially surrounds a work roll and serves as a supply manifold for nozzles arranged to apply cooling water to the roll surface. Although such devices operate in a generally satisfactory manner, it has now been determined that their efficiency is compromised by the Leidenfrost effect, a phenomenon in which a liquid, in near contact with a body significantly hotter than the liquid's boiling point, produces an insulating vapor layer that keeps the liquid from boiling rapidly. The thermal conductivity of the vapor is much poorer than that of the liquid, resulting in reduced cooling efficiency.
Broadly stated, embodiments of the present invention are directed to disrupting the Leidenfrost effect, thereby increasing the cooling efficiency of a liquid coolant being applied to a work roll surface.
In exemplary embodiments of the present invention, the application of the liquid coolant to a surface area of a work roll is accompanied by the simultaneous application to the same surface area of a pressurized gas.
Typically, the liquid coolant is water and the pressurized gas is compressed air.
In a preferred embodiment of a cooling device in accordance with the present invention, a manifold housing has a generally concave inner edge configured and dimensioned to surround a surface area of the work roll. The housing includes a first means for applying water or other like liquid coolant to the work roll surface area via first outlets arrayed along the housing inner edge, and second means for simultaneously applying compressed air or other like pressurized gas to the same work roll surface area via second outlets also arrayed along the inner housing edge.
Preferably the first nozzles are located in two parallel first planes, and the second nozzles are located in a second plane between and parallel to the first planes.
These and other features, objectives and advantages of the present invention will become more apparent upon reading the following detailed description in conjunction with the accompanying drawings.
The components described hereinafter as making up the various embodiments are intended to be illustrative and not restrictive. Other suitable components that are capable of performing the same or similar functions as well as the materials described herein are intended to be encompassed within the scope of the present invention.
With reference initially to
The cooling device 10 comprises a manifold housing 16 having a generally concave inner edge 18 configured and dimensioned to surround a surface area āAā of the work roll 12a.
With reference additionally to
Networks of first grooves 26 on the interior surfaces of the first housing sections 20a, 20b comprise a first means for applying a liquid coolant to the work roll surface area A via first outlets 28 arrayed along the inner edge 18 of the manifold housing 16.
With reference to
As can best be seen in
The network of first grooves 26 on the inner surface of exterior first section 20b are closed by an abutting surface of the interior second section 22. The network of second grooves 30 are closed by an interior cover plate 34.
The network of first grooves 26 on the interior surface of exterior first section 20a are closed by an outer abutting surface of the cover plate 34.
The networks of first grooves 26 may be supplied by liquid coolant received via external connections 36, and the network of second grooves 30 may be similarly supplied with pressurized gas via external connections 38.
In
The modular design of the cooling device 10 accommodates disassembly of the constituent sections 20a, 20b, 22 for periodic cleaning of the groove networks 26, 30 and associated outlets 28, 32. The groove networks and outlets are machined into the housing sections, and as such can be tailored to suit specific applications.
The cooling device of the present invention can readily be made from many different materials including metal plate, cast metal, plastic, ceramic, or composite materials. Thus, in a rolling mill environment where cooling water can often have entrained abrasive particles, an abrasion resistant material can be used. If the cooling water contains minerals that can adhere to passage walls, a non-stick lining or coating can be applied to interior surfaces. Corrosion-resistant coating may also be employed where appropriate.
The geometry of the manifold conduit can also be varied to provide each delivery outlet with near equal pressure thereby further optimizing coolant delivery.
Although not shown, it is to be understood that a second cooling device in accordance with the present invention and as described above is employed to cool the companion work roll 12b.
In light of the foregoing, it will now be understood that in accordance with the present invention, the application of a liquid coolant to a surface area of a work roll is simultaneously accompanied by the application of a pressurized gas to the same surface area. The application of pressurized gas serves to disrupt and eliminate or at least significantly reduce the Leidenfrost effect, thereby beneficially enhancing cooling efficiency.
Number | Name | Date | Kind |
---|---|---|---|
3357224 | Muller | Dec 1967 | A |
3880358 | Schaming | Apr 1975 | A |
4019560 | Butz | Apr 1977 | A |
4061010 | Dougan | Dec 1977 | A |
4226108 | Economopoulos | Oct 1980 | A |
4250951 | Christner | Feb 1981 | A |
4400961 | Schaming | Aug 1983 | A |
4422318 | Christ | Dec 1983 | A |
4688724 | Pal | Aug 1987 | A |
5046347 | Crosato | Sep 1991 | A |
5697169 | Jacob | Dec 1997 | A |
5855134 | Womelsdorf | Jan 1999 | A |
6385989 | Cassidy | May 2002 | B1 |
6904953 | Fecht | Jun 2005 | B2 |
8978437 | Malas | Mar 2015 | B2 |
20020162374 | Plicht | Nov 2002 | A1 |
20070175255 | Pawelski | Aug 2007 | A1 |
20110036555 | Plicht | Feb 2011 | A1 |
20150128677 | Dauphinais | May 2015 | A1 |
Number | Date | Country |
---|---|---|
2111885 | Jul 1983 | GB |
S63290610 | Nov 1988 | JP |
Entry |
---|
International Search Report and Written Opinion mailed Jan. 21, 2015 in corresponding PCT Application No. PCT/US2014/063085. |
Number | Date | Country | |
---|---|---|---|
20150128677 A1 | May 2015 | US |