| 摘要 |
PURPOSE:To efficiently cool steel plate and to prevent occurrence of cooling unevenness, by dividing forced cooling water from a pipe nozzle to pour water on steel plate, and providing means for preventing unbalanced local cooling at initial period in cooling a hot rolled steel plate. CONSTITUTION:At cooling the hot rolled steel plate 11, dividing vessels 19 are respectively provided just under respective pipe nozzle groups 18 of respective upper cooling headers 16 to receive cooling water from pipe nozzles 17. many water pouring holes 26 are provided to the vessel 19 so that cooling water from each nozzle 17 is divided by the holes 26 and can be poured on the plate 11. At initial cooling period of the plate 11, cooling water from the nozzle 17 is divided by the holes 26 and poured on the plate 11 to form retained water layer thereon. After the lapse of about 5-7sec from starting time of cooling, an oil hydraulic cylinder 24 is operated to dismantle the vessels 19 from underside position of the groups 18, and water is directly poured from the nozzles 17. At this time, since there is reservoir water layer on the plate 11, unvalanced local cooling is prevented. |
