# Calculation Method - Shell and Tube Exchanger

The Tubeside pressure loss for flow through a shell and tube exchanger is composed of 3 contributing parts: Δ P = Tube Friction Loss + Tube Entrance/Exit Loss + Nozzle Loss. 1) The tube friction loss is calculated assuming a tube roughness of 0.05mm, using the pipe equation calculation methods. 2) The tube entrance and exit losses are: For laminar flow: KTubes := 3.25 NTubePasses - 1.5. For turbulent flow: KTubes := 2.00 NTubePasses - 1.5. The tube Entrance/Exit Loss is then: 0.5 G2 KTubes / ρ. 3) The nozzle losses are: 0.75 G2 / ρ. The Shellside pressure loss is composed of 2 contributing parts: 1) The shell pressure loss is calculated according to the Delaware method. ΔP = 0.5 fD G2 (NBaffleCount + 1) Dis / (ρ Dh). The friction factor is determined from regression analysis of the charts provided in Serth [12] 2) The nozzle losses are calculated using: 0.75 G2 / ρ. The variables used in the above equations are described below. G is the mass flux. KTubes is the K factor determined as noted above. ρ is the fluid density. fD is the friction factor (Darcy). Dis is the inside shell diameter. Dh is the hydraulic diameter. NBaffleCount is the number of baffles. NTubePasses is the number of tube side passes. KTubes is the entrance/exit loss coefficient.