Chemical Graduate Engineer Trainee Interview Questions and Answers

Pressure decreases with altitude due to the decrease in air density as altitude increases.

• Pressure decreases by about 12% for every 1000 meters increase in altitude.

• This is because as altitude increases, the air becomes less dense, leading to fewer air molecules exerting pressure.

• For example, at sea level, the average atmospheric pressure is around 1013 hPa, while at the summit of Mount Everest, it is around 300 hPa.

Shell and tube heat exchanger is a type of heat exchanger that uses multiple tubes enclosed in a shell to transfer heat between two fluids.

• Consists of a shell (outer vessel) and tubes (inner vessels)

• One fluid flows through the tubes while the other flows around the tubes in the shell

• Heat is transferred from one fluid to the other through the tube walls

• Commonly used in industrial processes, HVAC systems, and refrigeration

• Examples include condensers, evaporators, and oil cooler...read more

Heat exchangers are devices used to transfer heat between two or more fluids, without them mixing together.

• Heat exchangers are commonly used in industrial processes, HVAC systems, and refrigeration systems.

• They work by transferring heat from one fluid to another through a solid wall, without the fluids coming into direct contact.

• Examples of heat exchangers include shell and tube, plate, and finned tube heat exchangers.

Radiation is the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles that cause ionization.

• Radiation can be classified into ionizing radiation (e.g. gamma rays, X-rays) and non-ionizing radiation (e.g. visible light, radio waves)

• Ionizing radiation has enough energy to remove tightly bound electrons from atoms, creating ions

• Radiation is used in various fields such as medicine (radiation therapy), industry (sterilizatio...read more

Laws of thermodynamics are fundamental principles governing energy and heat transfer in physical systems.

• First Law: Conservation of energy - energy cannot be created or destroyed, only transferred or converted.

• Second Law: Entropy always increases in isolated systems - heat naturally flows from hot to cold objects.

• Third Law: As temperature approaches absolute zero, entropy approaches a minimum value.

• Examples: A car engine converting fuel into motion follows the laws of thermod...read more

NPSH stands for Net Positive Suction Head and is a measure of the pressure available at the suction port of a pump.

• NPSH is important for ensuring that a pump does not cavitate, which can damage the pump and reduce efficiency.

• It is calculated by subtracting the vapor pressure of the liquid being pumped from the total suction head of the pump.

• NPSH is typically provided by the pump manufacturer and must be greater than the required NPSH for the pump to operate properly.

• If the NP...read more