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Drum Heat-Up Time Calculator
Enter what is in the drum, how far you need to raise it and how much band wattage you are putting on. The calculator returns the energy the batch needs and the hours a band of that rating takes to deliver it.
Your Batch
Band Wattage to Enter
Wattage comes from the model, not the drum. Add the bands together when more than one goes on the same drum.
| Model | Band width | Rating | Two bands | Three bands |
|---|---|---|---|---|
| FLB-SDH-250 | 250 mm (9.8 in) | 2,000 W | 4,000 W | 6,000 W |
| FLB-SDH-150 | 150 mm (5.9 in) | 1,000 W | 2,000 W | 3,000 W |
| FLB-SDH-125 | 125 mm (4.9 in) | 1,000 W | 2,000 W | 3,000 W |
Planning Values for Specific Heat
Take the figure from your medium’s datasheet whenever you have one. The entries below are planning approximations for a first pass, not property data for a specification.
| Medium | Planning value (kJ per kg per K) |
|---|---|
| Water and water-based solutions | 4.18 |
| Mineral and lubricating oils | 1.8 to 2.0 |
| Glycerine and glycols | 2.3 to 2.5 |
| Waxes and fatty acids, above the melt | 2.1 to 2.3 |
Why the Fraction Field Exists
A band wrapped on one third of the drum wall heats the contents through that contact area alone, and the uncovered wall loses heat to the room the whole time. The fraction field is where you say how much of the nameplate wattage you expect to reach the contents; 0.8 is a starting assumption for an indoor drum with the band covered by a jacket, and 0.5 to 0.6 suits an uninsulated drum outdoors.
Where the Answer Is Wrong
This calculation covers sensible heat only, so it does not include the energy that melts a solid or breaks a crystal structure. A wax or a fatty acid absorbs a large amount of energy at constant temperature while it melts, and the drum will sit at that temperature far longer than the number below suggests.
Send the batch details with your enquiry and the band count is worked out against your cycle time. Model specifications are on the silicone drum heaters page, and the Duty Class Selector converts an answer here into a band count.
Send Your Batch Details for a QuoteModel assumptions: energy = mass × specific heat × temperature rise; time = energy ÷ (wattage × fraction reaching the contents). Standing loss = exposed area × temperature difference × 8 W per m² per K, a planning figure for a bare vertical steel wall in still indoor air. Inputs are scoped to a net mass of 100,000 kg, and cooling is out of scope, so a target below the starting temperature returns no result.

