Question

In the slasher sizing machine, the principle involved in drying the wet warp sheet by physical contact with a hot drum surface is \(\underline{\hspace{2cm}}\)

• A. Conduction
• B. Convection
• C. Radiation
• D. Combined convection and radiation

Hint:

Think of the modes of heat transfer: - Conduction = Contact - Convection = Current (fluid movement) - Radiation = Rays (waves) The question specifies "physical contact," which directly points to conduction.

Answer 1

The Correct Option is A

Step 1: Analyze the process described. A wet warp sheet is dried by making "physical contact" with a "hot drum surface".

Step 2: Define the heat transfer principles.
- Conduction: Heat transfer through direct physical contact. Heat flows from a hotter object to a colder object they are touching.
- Convection: Heat transfer through the movement of fluids (liquids or gases). Hot air blowing over a surface is an example.
- Radiation: Heat transfer through electromagnetic waves, which does not require a medium. The heat from the sun is an example.

Step 3: Apply the principles to the scenario. Since the warp sheet is in direct physical contact with the hot drum, heat is transferred directly from the drum's surface to the wet yarn. This is the definition of conduction. While some convection (from hot air around the cylinders) and radiation might occur, the primary and dominant principle described is conduction.