Energy Saving and Process Optimization in a Conventional Hot Strip Mill by Application of the Latest High-efficient Descaling Technology

Abstract

The paper describes the conversion to a new generation of descaling nozzles in a conventional hot strip mill for steel. There are descaling stations behind the reheating furnace, on the roughing mill stands, and in front of the finishing mill. Before the converting, three high pressure pumps had been in operation to supply the descaling stations. The new descaling nozzles were tested first in the finishing mill descaler with good results. There were considerable water savings without compromising the descaling effect and the material surface quality. After a successful test, the remaining descaling stations were converted accordingly. The overall water saving was approx. 20%, which allowed shutting off one of the three high-pressure pumps. The electrical energy saving amounts to 30,000 kWh/day or about 9,300,000 kWh/year. At the current energy costs, this is equivalent to about 642,000 €. Additional advantages are also seen, such as reduced material cooling and the lower wear of the components of the whole high-pressure water hydraulic system.