VRM Heat & Mass Balance Calculator

⚙️ Vertical Roller Mill — Heat & Mass Balance Calculator

Cement Plant Process Tool  |  Single-file, browser-only  |  Design case: 385 t/h raw meal
v1.0
Tolerance (%): Max Iter:
Recycle Fraction:
0.00
Auto-solve on edit:
Not solved
Iterations:
Mass residual:
Heat loss:
Last solve:
📥 Feed & Process
🌬️ Gas Streams
🔥 Heat Balance
⚖️ Mass Balance
🏭 Unit Residuals
⚙️ Settings
📦 Raw Meal Feed Composition
ComponentWet%Wet Flow
(t/h)
Moisture
(%)
Dry Flow
(t/h)
Water
(t/h)
TOTAL
🌡️ Process Parameters
Production Capacityt/h (product)
Feed Material Temperature°C
Product Temperature°C
Mill Outlet Gas Temp.°C
Product Moisture Content% (wet basis)
Mill Water Injectionm³/hr
Product Residue (+90µm)%
Separator Efficiency%
Reference Temperature°C
⚡ Power Data
EquipmentkWh/tPower (kW)Speed
Mill Motor 2675
Fan Motor 1564
Separator Motor 12.1 rpm
Fan Speed rpm
kW = kWh/t × Production Rate (auto-computed)
🌬️ Gas Stream Measurements & Composition  Edit O₂, CO₂, H₂O vol% — N₂ is computed as remainder. Enthalpy computed automatically.
Measured Input
Computed
Editable
Stream P
(mmWg)
T (°C) Composition (vol%) Flow
(Nm³/min)
Flow
(m³/min actual)
Flow
(m³/hr)
Density
(kg/Nm³)
Mass Flow
(kg/hr)
Enthalpy
(Mcal/hr)
O₂%CO₂%H₂O%N₂%
(calc)
MW
🔥 Heat Balance — INPUTS
DescriptionMcal/hr%
THERMAL INPUTS
Heat content — Mill Inlet Gases
↳ Preheater gas
↳ Recirculation
Heat content — Feed Materials (dry)
Heat content — Feed Moisture
MECHANICAL INPUTS
Heat content — Mill Drive
Heat content — Fan Drive
TOTAL INPUTS100%
❄️ Heat Balance — OUTPUTS
DescriptionMcal/hr%
PRODUCT & GAS
Heat content — Raw Meal Product
Heat content — Exhaust Gas (to filter)
EVAPORATION
Latent Heat — Drying (feed moisture)
Latent Heat — Water Injection
UNACCOUNTED
Heat Loss (radiation, convection, etc.)
TOTAL OUTPUTS100%
📊 Heat Balance Summary
ParameterValueUnitStatus
Total InputsMcal/hr
Total Outputs (excl. loss)Mcal/hr
Unaccounted Heat LossMcal/hr
Heat Loss (%)%
Heat Consumption (excl. motor)kcal/kg product
Specific Drying Energykcal/kg water evap.
⚖️ Solid Mass Balance
StreamMass Flow (t/h)Status
INPUTS
Fresh Feed (wet)
Fresh Feed (dry)
Feed Moisture
Water Injection
Recycle Flow (to mill)
Mill Feed Total (dry)
OUTPUTS
Product (dry)
Product (moisture in product)
Water Evaporated
Separator Reject (gross)
Mass Balance Residual
📈 Circuit Performance
Circulation Factor
Separator Efficiency%
Specific Power — MillkWh/t
Specific Power — FankWh/t
Total Specific PowerkWh/t
Drying Capacity (feed moisture)t water/hr
Water Evaporation Ratekg/kg feed
🌊 Water Balance
WATER IN
Feed moisture
Water injection
Moisture in hot gas (H₂O)
WATER OUT (t/h)
In exhaust gas (vapor)
In product
Water balance residual
🏭 Unit Operation — VRM (Vertical Raw Mill)
ParameterInOutResidualUnit
Mass (dry solid)t/h
Mass (water)t/h
EnergyMcal/hr
🌀 Unit Operation — Dynamic Separator
ParameterIn (t/h)Product OutReject Out
Mass (dry)
Circulation factor
🌪️ Unit Operation — Cyclone / Dust Collector
ParameterValueUnit
Gas flow to filterNm³/min
Gas temperature at fan inlet°C
Cyclone pressure drop155mmWg
Gas energy (cyclone outlet)Mcal/hr
🏗️ Unit Operation — Hot Gas Duct / Preheater Connection
ParameterValueUnit
Preheater gas flow (measured)Nm³/min
Preheater gas temperature°C
Gas enthalpy (preheater)Mcal/hr
Hot gas damper opening% open
Recirculation damper% open
📤 Unit Operation — Stack / Exhaust
StreamFlow (Nm³/min)Temp (°C)O₂%Mass Flow (kg/hr)Enthalpy (Mcal/hr)Status
Gases to Filter/Stack
⚙️ Thermodynamic Settings
Cp solid (raw meal)kcal/(kg·°C)
Cp liquid waterkcal/(kg·°C)
Cp steam (H₂O vapor)kcal/(kg·°C)
Latent heat of evaporation (T_ref)kcal/kg
Mill drive thermal efficiency (η)— (0–1)
Fan drive thermal efficiency (η)— (0–1)
Gas Cp Coefficients: Cp = a + b·T [kcal/(kg·°C)]
Gasa (const.)b (×10⁻⁵/°C)MW (g/mol)
N₂28
O₂32
CO₂44
H₂O18
🧪 Reaction Chemistry (Optional)

Enable calcination reactions occurring in the preheater or mill. These add endothermic heat to the energy balance.

CaCO₃ → CaO + CO₂ (decarbonation)
CaCO₃ fraction in feed
Calcination degree in mill
ΔH_rxn (endothermic, +ve)
ΔH = 427 kcal/kg CaCO₃ = 3190 kcal/kg CO₂ released
Note: For raw grinding mills, calcination in the mill itself is typically <2%. The preheater cyclones do most calcination. Set calcination degree = 0 to exclude from mill energy balance.