Bøger af Sandeep Soni

Durante a laminagem o plano é mantido dentro das tolerâncias pelo sistema de controlo do plano, o objectivo importante deste trabalho é estudar o controlo do plano e melhorar a qualidade do produto laminado no laminador a quente. HAGC (sistema de controlo automático hidráulico de calibragem) é definido como um sistema de controlo do equipamento do laminador de linha para assegurar a espessura dos produtos laminados de modo a cumprir as tolerâncias alvo. Todo o trem de laminagem em stand by (desbaste e acabamento) equipado com tempo de reacção curto, repetição do cilindro hidráulico de curso longo e posicionamento de alta precisão (sem parafuso de pressão), espessura da fita pode atingir alta precisão. Depois de utilizar um cilindro hidráulico de curso longo, pode melhorar significativamente a precisão de controlo e a capacidade de resposta dinâmica, e reduzir significativamente o comprimento da zona de tolerância da espessura da fita.

During rolling the flatness is kept within tolerances by the flatness control system, the important objective of this work is to study about the flatness control and improve the quality of the rolling product in hot rolling mill. HAGC (hydraulic automatic gauge control system) is defined as a control system for line conditioning mill equipment to ensure the thickness of rolled products to meet the target tolerances. All the mill stand by (roughing mill and finishing mill) equipped with short reaction time, repeated the long-stroke and high precision positioning hydraulic cylinder (no pressure screw), strip thickness can achieve high accuracy. After using a long stroke hydraulic cylinder, can significantly improve control accuracy and dynamic response capabilities, and significantly reduce the length of strip thickness tolerance zone.

Boiler tubes may fail in service condition due to many reasons. Some of these reasons are: creep rupture, tube surface pitting, stress corrosion cracking, carbide graphitization, oxidation, sulfidation, caustic embrittlement, etc. Several other important factors often associated with component failures are deficiency in design, fabrication, operating conditions, unsuitable materials selection, and expended useful life. These conditions which gives rise to early failure of tubes. They are attributed to one or a combination of the above reasons. Waterside corrosion problems can seriously affect reliability of boiler systems. Two significant of waterside corrosion mechanisms are caustic corrosion and phosphate corrosion. Two critical factors contribute to these failures. The first is availability of NaOH or of alkaline-producing salts. The second contributing factor is the mechanism of concentration. These factors are of primary consideration. The tube failure study for evaluation is provided in a step by step approach. This includes collection of background information, mechanism and causes of failure, literature review, on-site inspection and data collection.