Skip to main content
[Combustion Systems]
Free tool

Incinerator Burn Rate

Screen an incinerator's declared throughput against the heat, combustion air, chamber loading and secondary residence time the unit can actually sustain.

[FREE_TOOLS]
Built by our engineers
[EXPLORE]
More tools, always free
[CALCULATOR]
Reference case

MAIN!C31 and CARCASSE-DATABASE!B3:B10. Batch mass and cycle are the spreadsheet's own.

Declared throughput

Time the whole cycle: loading, active burn and the final burndown to ash.

Waste composition
100.0% total
Combustion and hot zone
Equipment limits — optional

Every blank field is left out of the ceiling. Enter only ratings you can evidence.

Burn-rate screen
Declared throughput
45.0kg/h
Engineering ceiling
67.2kg/h
Governing constraintSecondary-chamber residence time
Regulatory classlow-capacity (<50 kg/h)

What limits the rate

Secondary-chamber residence time — governing67.2 kg/h
Auxiliary heat and 850°C heat balance89.0 kg/h

Working numbers

Corrected waste LHV0.762 MJ/kg
Required hot-zone volume0.779 m³
Actual wet gas flow1,402 m³/h
Combustion air274 Nm³/h
Heat margin32.6 kW
Mass-balance error0.000000 kg/h

Steady state, complete combustion, mean heat capacities. Transient peaks, leakage, burnout and emissions are excluded — the method is set out below the calculator.

[READ_THE_NUMBERS]

Results are indicative

Figures assume typical conditions and the stated method. For measured, guaranteed numbers on your plant, our engineers run site surveys, heat loss audits, and full process models.

[NEXT_STEP]

Send us the result — we'll tell you what it means for your plant.

[ABOUT_THIS_TOOL]

Incinerator Burn Rate Screening

Separates two numbers that are routinely, and expensively, treated as one:

Declared (regulatory) throughput — the rate the unit is operated at:

m˙declared​=tcycle​mbatch​​

where tcycle​ is the complete cycle: loading, active burn and final burndown to ash. Using only the active burn period inflates the figure, often by a factor of two.

Engineering screening ceiling — the lowest rate the entered equipment can support. Each populated limit is inverted into a maximum burn rate and the smallest one governs:

  • secondary-chamber residence time at the required hot-zone volume;
  • combustion-air capacity to hold the target wet O₂;
  • maximum permitted or nameplate thermal input;
  • primary-chamber loading (volume × fill fraction × bulk density ÷ dwell time);
  • the auxiliary-burner heat balance at the secondary set point.

Blank equipment fields are excluded, so the ceiling only ever reflects data you actually entered.

Method

Waste composition is entered as received and must total 100% ±0.5%. The tool runs a Dulong-style HHV/LHV estimate, stoichiometric oxygen demand for C, H, O, N, S and Cl, auxiliary natural gas approximated as methane, combustion air solved to the entered wet O₂ target, and a species mass balance with an automated closure check. Flue-gas volume is evaluated at the actual secondary temperature and absolute pressure. Normal volumes are at 0 °C and 101.325 kPa.

Regulatory context

50 kg/h is the UK boundary between the low- and high-capacity incineration routes. Animal by-product plant is commonly operated on either the 850 °C for 2 s or the 1100 °C for 0.2 s secondary route; both are selectable.

What it does not model

Refractory warm-up, batch-release peaks, combustion kinetics, CO and unburned carbon, fan pressure, air leakage, detailed radiation and convection, ash burnout and emissions. Those need a dynamic design model and commissioning data — this is a screening tool, not a certified capacity statement.

[UPGRADE]

Need this tool, but deeper?

We build advanced versions on request — your fluids, your geometry, your standards, validated against plant data.

[REQUEST]

Missing a calculator?

Tell us what you're sizing or estimating — we build the calculators engineers actually ask for.

[FAQ]

Frequently asked questions

Batch mass divided by the complete cycle time — from first load to fully burned down, including loading and the final burndown. Not the peak rate during active burning, and not the burner's firing rate. A 450 kg charge over a 10-hour cycle is 45 kg/h, even if the middle of the burn is far faster than that.

They answer different questions. The declared throughput is how you operate the unit: charge mass over the full cycle. The engineering ceiling asks whether the equipment you entered can sustain that rate — hot-zone volume, air capacity, thermal input, loading and the heat balance. If the ceiling is below your declared rate, the unit cannot really do what it is rated at.

It is the UK boundary between the low-capacity and high-capacity incineration routes, and the two carry very different permitting and monitoring obligations. A unit declared just under 50 kg/h on an optimistic cycle time can be pushed over the line by an honest recalculation, so it is worth checking before the declaration is made.

Waste compositions taken from an existing carcass-incinerator spreadsheet, kept for comparison. Only the MAIN sheet case carries a real batch mass and cycle (450 kg over 10 hours). The others are composition samples placed on an assumed one-hour cycle purely to reproduce the rate that was typed into the original sheet by hand. Replace both numbers with your measured batch mass and full cycle before reading anything into the result.

No. It is a screening calculation from the values you enter, and it deliberately excludes transient effects, leakage, burnout and emissions. Use it to sanity-check a proposed rating or spot a unit that is over-declared, then validate the final figure against measured flows, commissioning trials and the applicable permit. Our engineers can run that study.