Foundry & Forging worked example

Furnace Charge Calculator at 17% charge handling allowance: a worked example

What does the result look like when charge handling allowance reaches 17%? The full calculation is worked below with real intermediate numbers. Use it when the melt shop needs to schedule charge loading, alloy additions, returns, pig, scrap, flux, furnace door time, and operator labor.

The inputs for this scenario

  • Charge buckets or batches required: 8 batches (unchanged)
  • Charge loading rate: 2 batches / hr (unchanged)
  • Charge handling allowance: 17 % (raised for this scenario; the documented default is 15)

Working through the calculation

  • Applying the documented formula (Base furnace charge calculator = charge weight or buckets required รท charge loading completion rate) to the inputs above produces each figure below.
  • At this operating point the engine returns 4.68 hr for required furnace charge time, the number this scenario is built around.
  • At this operating point the engine returns 4 hr for base furnace charge calculator.
  • At this operating point the engine returns 17 % for charge handling allowance.
  • At this operating point the engine returns 2 pieces / min for charge loading completion rate.

How this compares with the baseline

  • Against the tool's baseline example, where charge handling allowance sits at 15% and the headline result is 4.6 hr, this scenario comes in 1.74% above the baseline at 4.68 hr.
  • A figure at this level is achievable when charge handling allowance is genuinely sustained, not just peaked for a shift. It assumes a steady loading rate; in practice the first heavy returns and the final trim-charge often load slower, so the allowance must absorb that variation.

Results at a glance

  • Required furnace charge time: 4.68 hr (headline result)
  • Base furnace charge calculator: 4 hr
  • Charge handling allowance: 17 %
  • Charge loading completion rate: 2 pieces / min

Run it with your numbers

  • Every input above is editable in the live Furnace Charge Calculator calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.