Furnace operations context: Which of the following industrial furnaces is typically operated in batch mode (charge is heated in discrete lots rather than in a continuous stream)?

Introduction / Context:
Industrial furnaces can be classified by how material flows through them: batch (charges are processed in discrete lots) or continuous (material moves steadily through the hot zone). Being able to identify common furnace types by their operating mode is essential in furnace technology and thermal process design.

Given Data / Assumptions:

• Cupola furnaces are used in foundries for continuous melting of iron.
• Reheating furnaces can be designed and operated either as batch (soak/box) or as continuous (pusher/walking beam); the question seeks an example that is typically run in batch mode.
• Glass tank furnaces commonly run continuously for long campaigns.
• “Batch crucible furnace” is a generic label but not one of the main canonical industrial choices provided in the stem; it is added as a distractor.

Concept / Approach:
Batch furnaces heat a stationary charge to target temperature and soak it, then unload and reload. Many heat-treatment and forge shops rely on batch reheating furnaces (box or car-bottom types) to bring billets/forgings to temperature for subsequent deformation. By contrast, cupolas and glass tank furnaces are iconic continuous units.

Step-by-Step Solution:
Identify which option is commonly batch: reheating furnaces are very often batch in forging/heat-treatment service (though continuous variants exist).Eliminate continuous examples: cupola (continuous melt), glass tank (continuous glass production).Select the best match: Reheating furnace.

Verification / Alternative check:
Operating practice: batch reheating furnaces load material on racks or cars, heat/soak to uniform temperature, then discharge. This clearly matches batch operation behavior.

Why Other Options Are Wrong:
Cupola: classic continuous melting with continuous tapping.Glass tank furnace: designed for continuous pull of molten glass.None of these: incorrect, as a batch-operated reheating furnace is a standard unit.Batch crucible furnace: while batch by nature, it is a distractor not matching the main industrial choices emphasized in the stem.

Common Pitfalls:
Assuming every reheating furnace is continuous; many facilities still use batch box/car-bottom designs for flexibility and scheduling.

Final Answer:
Reheating furnace