Abstract: A cooling system for cooling a metal strip moving horizontally along a roller conveyor has a plurality of water boxes (4) arranged between the rollers (1,2,3) of the roller conveyor and each having upwardly directed outlet ducts (6) from which cooling water is projected onto the underside of the metal strip. The ducts (6) are parallel to each other and uniformly spaced across the width of the strip. To improve cooling, particularly its uniformity, the outlet ducts (6) are all shaped and oriented so as to project the cooling water with a component of motion opposite to the direction of movement of the metal strip, and each water box (4) is shaped and located relative to the next preceding roller (1,2,3) in the direction of movement of the metal strip so that during operation the water projected from each water box also cools said next preceding roller.

Abstract: A gas which is intermittently and/or irregularly released e.g. carbon monoxide-containing gas from an oxygen steel converter, is collected in a gas holder and delivered from the gas holder to a user installation. To avoid wastage of gas when the average release of gas varies and to permit use of a smaller gas holder, the output rate from the gas holder is determined by deriving a modified filling level signal by filtering a filling level signal of the gas holder so as to attenuate frequencies in the filling level signal above a predetermined limit frequency by a factor of at least ten, and adjusting the rate of delivery of the gas from a gas holder in dependence on variations in said modified filling level signal, such adjustment being in the same direction (up or down) as the variation in the modified filling level signal.