Lecture2
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The document discusses heat transfer concepts and equipment used in petrochemical engineering processes. It defines heat transfer and the main types of heat exchangers used, including double pipe exchangers, shell and tube exchangers, plate and frame exchangers, and fired heaters. It specifically focuses on pipe still heaters, classifying them according to their mode of heat transfer, charging method, and type of fuel used.
Lecture2
- 2. Syllabus Unit I Heating of crude oil through exchangers. Pipestill heaters, their types and constructional features, estimation of heat duty, combustion calculation and heat transfer area in different parts in pipe still heater. Calculation of pressure drop and stack height
- 3. Designing & Optimization in Petroleum Refining • Petroleum refining is a major industry • Petroleum products are most important fuels • Petroleum are the starting point for many syntheses in the chemical industry. • Optimization is the process of determining the best possible way of selecting the process scheme and fixing the unit schemes etc.
- 4. Heat transfer • Basic Definitions • Heat transfer is the science which deals with the rates of exchange of heat between hot and cold bodies called as source and receiver. • Process heat transfer deals with the rates of heat exchange as they occur in the heat transfer equipment of the engineering and chemical processes. • Exchangers recover heat between two process streams. • Heaters are used preliminary to heat process fluids. • Coolers are employed to cool process fluids. • Condensers are coolers whose primary purpose is the removal of latent heat. • Reboilers is to supply the heat requirements of a distillation process as latent heat.
- 5. • Evaporator s are used for the concentration of a solution by evaporation of water. • Vaporizers – Evaporation of any other fluids except water.
- 6. Principal Types of Heat Exchanger 1. Double-pipe exchanger: the simplest type, used for cooling and heating. 2. Shell and tube exchangers: used for all applications. 3. Plate and frame exchangers (plate heat exchangers): used for heating and cooling. 4. Plate-fin exchangers. 5. Spiral heat exchangers. 6. Air cooled: coolers and condensers. 7. Direct contact: cooling and quenching. 8. Agitated vessels. 9. Fired heaters.
- 7. Double Pipe Exchangers Usually assembled in 12-, 15- 20ft effective length
- 8. • Advantages • Easy to assemble by using standard parts • inexpensive • Disadvantages • Small heat transfer area • Requires large floor area for the battery of exchangers • Each exchangers introduces more than 14 potential leakage points • High maintaince cost and time requirement
- 9. Shell and Tube Heat Exchangers
- 10. Pipe Still Heaters • Classification • According to mode of heat transfer • Open fired furnace • Heated through medium • According to mode of charging • Batchwise • Continuous • According to mode of recovery • Regenerative • Recuperative • Depending on fuel • Combustion type • Electric type