Flash Separator – Material Properties Method

Material mass flow M kg/h Known

Material density ρ₁ kg/m³ Known

Specific heat Cp kJ/(°C·kg) Known

Initial temp t₀ °C Known

Final temp t₁ °C Known

Latent heat r kJ/kg Look-up table

Steam temp T °C Known

Steam density ρg kg/m³ Look-up table

Selected diameter D' m Custom

Residence time t min Design

VL = M/ρ₁ m³/h

M' = M·Cp·(t₀−t₁)/r kg/h

V = M'/ρg m³/h

U = 0.0512((ρ₁−ρg)/ρg)^0.5 m/s

D = (V/(3600·0.785·U))^0.5 m

Ua = V/(3600·0.785·D'²) m/s

HL = VL·t/(47.1·D'²) m

HG (if 0.1D<150, HG=150+1.2D, else 1.3D) mm

H = HL + HG mm

Evaporator Separator Chamber

Secondary steam rate W kg/h

Steam density ρ kg/m³

Volume intensity U m³/(m³·s) 1 ~ 1.5

Height / Diameter ratio (H/D) 1 ~ 2

V = W/(3600·ρ·U) m³

D m

H = D · (H/D) m

Rounded D m

Rounded H m

Actual H/D

Inlet liquid vol. flow m³/h

Inlet velocity m/s 1.5~2

Inlet pipe ID mm

Outlet liquid vol. flow m³/h

Outlet velocity m/s

Outlet pipe ID mm

Drain vol. flow m³/h

Drain velocity m/s 0.8~1.8

Drain pipe ID mm

Secondary steam vol. flow m³/h

Steam velocity m/s 30~50

Steam pipe ID mm

Typical design velocities used in the evaporator/separator nozzle sizing section above.