| Abstract:After introducing the principle of air ventilation and moisture removed of the closed steam hood, the key and difficult points for control were analyzed. Aiming at the coated white paper board machine with surface sizing and high steam consumption, a SIMATIC S7-300 PLC based DCS control system for closed steam hood was designed. The paper illustrated the advanced control algorithms or control strategies such as the selection control of the temperature and humidity of the discharged air, the feedforward and feedback control of the steam hood zero-level pressure, the split range control of the hot feed air, the intelligent control of fire protection, optimization control of energy consuming, etc. Several pieces of advice on paper board machine closed steam hood design were proposed at last. The control system proposed in this paper has been used in nearly 10 paper board plants in the coated white paper board base of Fuyang, Zhejiang province and satisfactory energy-saving performances were reported. |
