So velocity selected should be just enough to prevent settling of suspended soilds. High fluid velocities increases heat transfer coefficients and reduces fouling but causes erosion and increases pressure drop. The following table (Table-1) provides general guidelines for shell and tube side fluid allocation in a shell and tube heat exchanger: Fluid Parameters Fluid Allocation-Shell Side Fluid Allocation-Tube Side High Pressure Fluid Stream X Corrosive Fluid X High fouling fluid stream X More Viscous fluid X Lower Flow Rate Fluid X Fluid with low heat transfer co-efficient X Toxic Fluid X Table 1: Shell and Tube-side Fluid Allocation Fluid Velocity inside Shell and Tube General design Considerations for shell and tube heat exchanger Fluid Allocation: Shell side vs Tube Side Once the requirements are met, a process datasheet is developed indicating all process design parameters of shell and tube heat exchanger design. Otherwise, adjust the assumed geometry and repeat the above steps. If the pressure drop is within the allowable pressure drop design is acceptable.Comparison of shell and tube-side pressure drop with allowable pressure drop.Comparison of calculated area with the assumed geometry.Estimation of required heat transfer area.Calculation of Mean temperature difference (log mean temperature difference) from the inlet and outlet temperatures of the two fluids.Determination of wall resistance and overall heat transfer coefficient.Estimation of tube side heat transfer coefficient and pressure drop.Calculation of shell side flow distribution and heat transfer co-efficient.Further steps for the shell and tube heat exchanger design consist of

Tube in tube condenser design