When we often use pressure processing steel, rolling steel can change the shape of rotating rolls. According to the different treatment methods, steel rolling can be divided into hot rolling, cold rolling, longitudinal rolling, transverse rolling, oblique rolling, periodic rolling, rotary rolling and bending forming, etc. The main uses of these processes are two. One is to process materials such as steel plate, strip steel, wire rod and various section steel to the required shape; the other is to improve the internal quality of steel by changing the form of materials, so as to promote the quality of steel.To meet the high-speed responsiveness, the system uses PLC and FGI FD300 frequency inverter for PROFIBUS-DP protocol communication.

In order to save energy and reduce urban pollution, the waste heat of steam turbine after power generation from thermal power plants is fully utilized to provide central heating for northern cities in winter. When the hot water from the power plant is sent to the urban heat exchange station, the temperature of the primary water supply is above 90 degrees. After the heat exchanger, the hot water temperature of a return water is reduced to more than 60 degrees, and then returned to the power plant. The hot water sent to the homes of urban residents, the secondary return water temperature into the heat exchanger of the heat exchange station is above 50 degrees, and the secondary water supply temperature is above 60 degrees. There are many such heat exchange stations in Baoji City, Shaanxi Province, including a heat exchange station with 4 heat exchangers, a circulating pump group consisting of 4 37kW pipeline pumps, and a 3.7kW supplementary pump. The circulation pump and filling pump use manual opening and closing valve to control the flow rate, which increases the damping of the pipeline and causes power waste. In order to further save energy, the heat exchange station has been automatically transformed, using FD100 frequency inverter produced by FGI company to adjust the circulation pump and supplementary pump, and the entire urban heating system is monitored by computer to achieve unattended heat exchange station.