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: Evaluate the process. A wet warp sheet dries via "physical contact" with a "hot drum surface".

Step 2: Explain heat transfer methods.
- Conduction: Heat transfer through direct contact. Heat moves from a hotter to a colder object in contact.
- Convection: Heat transfer via fluid (liquid or gas) movement. Hot air over a surface is an example.
- Radiation: Heat transfer through electromagnetic waves, needing no medium. Sunlight is an example.

Step 3: Apply principles to the scenario. Direct contact between the warp sheet and the hot drum results in heat transfer from the drum to the wet yarn. This is conduction. Although convection (from surrounding hot air) and radiation may occur, conduction is the primary method.