Computer Control System For Sewage Disposing Of Steel Manufactory

Although a sewage disposing system has great social benefit, it is a fact that the cost is high, and the economic benefit is low. It is necessary to apply the computer control technology for semi-automatic or full-automatic control on the process of sewage disposing.Considering the actual control requirement in sewage disposing, this paper compares and analyzes several industry network patterns in an integrated automatic system's integrality, reliability, extendibility and open capability, and brings forwards a communication network system, which is based on PROFIBUS field bus. It also offers the network's constituent parts and the steps of setting the network. The upper computer includes an industrial control computer, a display in charge of watching and administration and a printer in charge of recording data; the lower one is the PLC whose duty is to control and collect information; the real-time communication between them is through PROFIBUS-DP local bus.And then this paper expatiates the electric control request of the system and the software and hardware design of the upper and lower computer. Since there are so many pumps and valves whose control methods are familiar that this paper only expatiates the control of the pumps and valves in measuring pool and the others are only offered with the constituent parts and basic programming flows. There are many difficulties in PH value control of the sewage disposing such as no-linearity and delay. Based on the traditional PID control method and the original scheme of the system, this paper brings up severel improved control methods.In view of the high-power equipments, the local control station's designs adopt frequency changer and soft motor starter to save energy and protect equipments.