SOL ALPHA
Evaporation · Kettle reboiler

Design a kettle reboiler for a distillation column

Systematically determine evaporation duty, heating area, circulation hydraulics and pressure parts of a kettle reboiler.

5 solution steps6 suggested modulesStatus: solution concept

The engineering task

The bottom of a distillation column requires a defined vapour rate. The heating medium must transfer the latent heat without excessive wall superheat or unstable two-phase flow.

Liquid level above the bundle, vapour disengagement area, freeboard, entrainment and inlet/return pressure losses must be assessed together. Mechanical design follows only after thermal and hydraulic geometry has been fixed.

Required design data

  • Bottom composition, pressure and required vapour rate
  • Heating medium, condensing state and available pressure
  • Allowable pressure drop and surface heat flux
  • Turndown, fouling and control concept

Technical solution approach

Convert separation duty into heat duty

Determine reboiler duty from vapour rate, composition and latent heat.

Evaluate boiling conditions

Check boiling temperature, driving force and allowable heat flux with adequate margin to critical heat flux.

Size bundle and vapour space

Select area, tube layout, liquid coverage and disengagement area for stable boiling without excessive entrainment.

Close the hydraulic feedback

Inlet, return, static head and two-phase losses determine circulation and are iterated with heat transfer.

Design pressure parts and relief

Verify tubesheet, shell, heads and nozzles, including a high-pressure heating-side breakthrough case.

Expected deliverables

Reboiler duty and vapour rate
Heating area and bundle geometry
Circulation and two-phase hydraulics
Pressure-part and relief verification

Suitable SOL ALPHA modules

The modules form a technically plausible toolchain. Their final selection and sequence will be confirmed during the later calculation against the applicable code and project conditions.

SCUTProcess designMulticomponent distillationprovides the separation duty and required vapour rate→NAVEThermal designHeat transfer in evaporatorscovers heat transfer in the evaporator→VERDThermal designVaporization of pure substances in shell-and-tube or double pipe heat exchangerscalculates vaporisation in the tube bundle→TSIPHydraulicsHydraulic balance for kettle reboilerscloses the hydraulic balance→E135Mechanical designFixed tubesheetsverifies the fixed tubesheet→A2SafetySafety facilities to protect against pressure transgression: Safety valvessizes relief for heating-side breakthrough→