A side spray method for cooling the steel strip after hot rolling

A side spray method for cooling the steel strip after hot rolling, comprising the following steps:

• a) providing side spray devices behind multiple cooling sections on both sides of run out roller table of the steel strip after hot rolling, wherein the side spray devices are staggered along the two sides of the run out roller table of the steel strip, the side spray devices include at least two spray units, each spray unit includes spray tube and nozzles on the tube, the spray tubes being in parallel and vertically arranged along running direction of the steel strip, and being movable along the running direction of the steel strip;
• the covering ranges of the nozzles on the side spray devices are partially overlapped, and a total spray coverage covering of nozzles covers the width of the run out roller table of the steel strip;
• side spray water collecting devices are provided on the other side of the run out roller table of the steel strip that is opposite to side spray devices, so that side spray water being collected by the water collecting devices;
• b) controlling the side spray devices in a mode of open-in-pairs, wherein multiple cooling sections and side spray devices are numbered in the running direction of the steel strip after hot rolling, when the valve at the cooling sections with odd number is opened, two consecutive staggered side spray devices behind the cooling sections are opened at the same time;
• when the valve at the cooling sections with even number is opened, the side spray device behind the cooling sections has been already open, and no further side spray device needs to be open.