초록 ▼

(EN) The present invention relates to a device for cooling a working roll (1, 2) belonging to a rolling stand used for rolling a long or flat product (3), characterized in that it comprises a cooling head in the form of a box section (6A, 6B) that is sealed except along a front face (42) lying a sho

(EN) The present invention relates to a device for cooling a working roll (1, 2) belonging to a rolling stand used for rolling a long or flat product (3), characterized in that it comprises a cooling head in the form of a box section (6A, 6B) that is sealed except along a front face (42) lying a short distance from said roll (1, 2), and in which face a plurality of nozzles (41) has been machined or positioned in a determined pattern, said box section (6A, 6B) being concave and cylindrical at its front face (42). The box section (6A, 6B) is also fitted with transverse (5, 7) and lateral (8) plates which collaborate with the front face (42) of the box section so as to control the flow of cooling liquid and confine said liquid in the form of a highly turbulent flow. This then yields optimal cooling of the roll both in terms of the uniformity of the cooling across the surface thereof and in terms of the reduction in temperature as a result of the turbulent effect created.

대표청구항 ▼

1. Rolling stand for rolling a long or flat product comprising a work cylinder (1,2) and a device for cooling said work cylinder (1,2), characterised in that it comprises a cooling head in the form of a box that is more or less watertight in itself (6A,6B) except on its front (42), positioned a shor

1. Rolling stand for rolling a long or flat product comprising a work cylinder (1,2) and a device for cooling said work cylinder (1,2), characterised in that it comprises a cooling head in the form of a box that is more or less watertight in itself (6A,6B) except on its front (42), positioned a short distance from said cylinder (1,2) and in which several nozzles (41) have been machined or positioned according to a two-dimensional pattern, said box (6A,6B), equipped with a means for supplying a liquid coolant, being concave and cylindrical at a level of its front (42) with a radius such that, when the device is in the working position, a distance in the radial direction between said front (42) and the surface of the cylinder (1,2) increases starting from the end of the box (6A,6B) closest to the rollgap (9) and going away from the product being rolled. 2. Rolling stand as in claim 1, wherein the cooling head (6A,6B) is equipped with a transverse lower plate (5,7) positioned lengthwise relative to the cylinder (1,2) and located at a distance from the cylinder (1,2) such that said lower plate (5,7) co-operates with the front (42) of the box in order to ensure the control of the flow of liquid coolant and its confinement in the form of a highly turbulent water pillow. 3. Rolling stand as in claim 2, wherein the cooling head (6A,6B) is moreover equipped with adjustable side plates (8) positioned at the side of the transverse ends of the cylinder (1,2) and located at a distance from the cylinder (1,2) such that said side plates (8) co-operate with the front (42) of the box and with the transverse lower plate (5,7) in order to ensure the control of the flow of liquid coolant and its confinement in the form of a highly turbulent water pillow. 4. Rolling stand as in claim 3, wherein the curve of the side plates (8) matches the maximum curve of the cylinders (1,2) used in the installation. 5. Rolling stand as in claim 1, wherein the front (42) comprises a plate or sheet in which are positioned or machined the nozzles (41) whose apertures are made of little holes of straight axial cross-section. 6. Rolling stand as in claim 5, wherein the apertures of the nozzles (41) are of round, square or oval transverse cross-section. 7. Rolling stand as in claim 1, wherein the radius of the cylindrical concave surface of the front (42) has a value higher than the predetermined maximum value of the radius of the cylinder (1,2), which restricts the range of size of usable cylinders. 8. Rolling stand as in claim 1, wherein the machining pattern of the nozzles (41) is selected so as to make the cooling of the cylinder as homogeneous as possible across the whole surface of the cylinder (1,2) and in particular across the width of the cylinder. 9. Rolling stand as in claim 5, wherein the machining pattern of the nozzles (41) is defined by the number, position and diameter or size of the apertures in the plate of said front (42). 10. Rolling stand as in claim 9, wherein the apertures are machined according to a specified matrix and wherein the above-mentioned pattern is obtained by blocking some apertures. 11. Rolling stand as in claim 1, wherein the liquid coolant comprises water. 12. Method for cooling a work cylinder in a rolling stand for a long or flat product, in particular a metal strip (3), implementing the device of claim 1, wherein: the cooling head is positioned close to the surface of the cylinder in order to create a gap of between 5 and 200 mm between the front (42) of the box (6A,6B) and said surface of the cylinder (1,2), said gap increasing starting from the rollgap (9) and going away from the product being rolled;the cooling head is supplied with liquid coolant, preferably water, and this water is sprayed into said gap through nozzles (41) having apertures with a diameter of between 1 and 6 mm;the pressure of the liquid coolant is adjusted to a value of between 1 and 6 bar and the specific flow rate between 100 and 500 m3/hour/m2, in order to create in the above-mentioned gap a liquid pillow in a highly turbulent state. 13. Method as in claim 12, wherein the pressure of liquid coolant in the box (6A,6B) is below 4 bar. 14. Method as in claim 13, wherein the pressure of liquid coolant is between 2 and 4 bar. 15. Method as in claim 12, wherein the distance between the transverse lower plate (5,7) and the cylinder (1,2) is adjusted so as to obtain in the gap a specific flow rate of liquid of between 2 and 10 m/s, and preferably greater than 3 m/s. 16. Method as in claim 12, wherein the side plates are adjusted so as to have a minimum aperture of between 0 and 10 mm. 17. Rolling stand as in claim 1, wherein the box of the device maintains a fixed position relative to the cylinder. 18. Rolling stand as in claim 1, wherein the nozzles emit straight jets of the liquid coolant. 19. Method of claim 12, further comprising the step of fixing the position of the cooling head relative to the cylinder.