METHOD OF CLEANING CYLINDERS OR ROLLS
A method of cleaning cylinders ( 5 ) and/or rolls ( 5 ), e.g., working rolls ( 5 ) in a rolling stand, wherein a liquid is sprayed onto the cylinders ( 5 ) at high pressure through several nozzles (D 1 -Dn) of a number of nozzles (D 1 -Dn) stationary arranged in and/or on a nozzle beam ( 10 ), with at least one on-off valve being associated with each nozzle (D 1 -Dn), and one or several nozzle(s) (D 1 -Dn) are sequentially switched on and off one after another starting from one end of the nozzle beam.
1 . A method of cleaning working rolls of a rolling stand, comprising the steps of providing an apparatus for cleaning a working roll and including a beam extending in a longitudinal direction of a cleanable roll, a plurality of nozzles for spraying a cleaning liquid under pressure onto the roll, supported on the nozzle beam and arranged in a row extending in a longitudinal direction of the cleanable roll from one end of the nozzle beam to another end of the nozzle beam, with the nozzles being arranged in pairs of adjacent nozzles following one another in the longitudinal direction of the cleanable roll, and a plurality of on-off valves with a single on-of valve being used for switching each pair of adjacent nozzles; and upon staring a cleaning process, sequentially and simultaneously switching each pair of adjacent nozzles on and off, starting from the one end of the beam.
2 . A method according to claim 1 , wherein a third nozzle pair, in the longitudinal direction of the cleanable roll, of a set of three, following one another nozzle pairs, is switched on when a first nozzle pair of the set of the three following one another nozzle pairs is switched off.
3 . A method according to claim 1 , comprising the step of starting a new cleaning period immediately after an end of the working roll ( 5 ) opposite the another end of the nozzle beam has been cleaned.
4 . A method according to claim 3 , wherein a further cleaning period following the new cleaning period is carried out with a time delay.
5 . A method according to claim 1 , wherein switching of respective pairs of at least two adjacent nozzles on and off depends on a roll speed.
6 . A method of cleaning working rolls of a rolling stand, comprising the steps of providing an apparatus for cleaning a working roll and including a beam extending in a longitudinal direction of a cleanable roll, a plurality of nozzles for spraying a cleaning liquid under pressure onto the roll, arranged in a row extending in a longitudinal direction of the cleanable roll from one end of the nozzle beam to another end of the nozzle beam and supported on the nozzle beam, and a plurality of on-off valves for switching respective nozzles (D 1 -Dn) on and off; and upon starting a cleaning process, sequentially switching the nozzles on and off starting from the one end of the nozzle beam to another end of the nozzle beam, with every third nozzle, in the longitudinal direction of the cleanable roll, of a set of three, following one another, nozzles being switched on when a respective first nozzle of the set of three following one another nozzles is switched off.
7 . A method according to claim 6 , comprising the step of starting a new cleaning period immediately after an end of the working roll ( 5 ) opposite the another end of the nozzle beam has been cleaned.
8 . A method according to claim 6 , wherein a further cleaning period following the new cleaning period is carried out with a time delay. A method according to claim 6 , wherein switching of nozzles on and off depends on a roll speed.