| Author | Jeeradej Satayayut |
| Call Number | AIT Thesis no. ET-90-19 |
| Subject(s) | Steel industry and trade--Energy consumption
|
| Note | A thesis submitted in partial fulfillment of the requirements of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | With rapid growth in demand for steel products and increase in energy
prices, reduction of energy consumption and increased productivity in the iron
a nd steel industry are now important considerations. In this study, energy auditing
was carried out at the Siam Iron and Steel Factory, with special focus on the
reheating furnace, ladle preheater, and electric arc furnace. The results of energy
analysis on the reheating furnace based on the first a nd second law analyses of
thermodynamics show that the first and second law efficiencies of the reheating
furnace are 37% and 20% respectively. Economic analysis in several areas o f the
reheating system were done to identify energy conservation opportunities. The
reduction of excess air and hot chargfr1g of billets offer great potential for energy
cost savings, reducing the total energy cost by half for the reheating system.
A dynamic ladle preheater model for prechecking heat-up time has been
developed and validated with experiments performed with the existing ladle.
preheater. The results predicted by the model are sufficiently accurate and the
model is convenient to use. Various important operating parameters are investigated
by using the developed model for the purpose of energy conservation and
improvement of ladle preheating. The results obtained show that the increase in
oxygen enrichment leads to appreciable energy savings, shorter heating time as
well as productivity improvement.
The electric arc furnace, the largest energy consumer in [-.his mill, was
analyzed based on the first law of thermodynamics. The results obtained showed
t hat this process of billet manufacturing from scrap iron has a specific energy
consumption of 560 kWh per ton billet fi nd the first law efficiency is 66% including
the partial furnace heat recovery to preheat the scrap. Modified first-law efficiency
which considered the chemical energy from exothermic reactions as inherent
energy input. was 52%. A model for predicting t he temperature profile of molten
steel in the preheated ladle during transfer from arc furnace to the caster was
developed by using the results of ladle preheater model as input. parameter and
validate d with the measured data. The results indicate that rapid temperature
drop takes p lace during bubbling period due to the high heat loss with nitrogen
gas and the preheating of ladle to a higher temperature without oxygen enrichment.
is not economical due to the inefficient preheating using the existing burner and
the low flame temperature of fuel that is used. Ins11lation of exposed surface of
molten steel during casting is more attractive for energy saving in the arc
furnace.
Finally, various energy consecration opportunities for the arc furnace were
studied and a summarized evaluation of the overall energy saving potential in
this steel mill was proposed. |
| Year | 1990 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Energy Technology (ET) |
| Chairperson(s) | Mohanty, B.
|
| Examination Committee(s) | Mora, Jean-Claude ;Surapong Chirarattananon ;Bo, Khin
|
| Scholarship Donor(s) | The Government of Australia |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1990 |