1. CHEMCAD Seminar Heat Transfer John Edwards, P&I Design Ltd
January, 2015 1

2. CRYOGENIC BATCH REACTOR OPTIMISATION
HEAT TRANSFER SESSION OBJECTIVES
CRYOGENIC BATCH REACTOR OPTIMISATION
Design procedure for shell and tube heat exchanger sizing
Design parameters review
TEMA layouts
Heat exchanger performance and fouling rating
Consider sensible heat and phase change heat exchangers
Design Margin and Fouling

3. CRYOGENIC BATCH REACTOR OPTIMISATION
HEAT TRANSFER BASIC THEORY
CRYOGENIC BATCH REACTOR OPTIMISATION
Section 7 page 229

4. CRYOGENIC BATCH REACTOR OPTIMISATION
HEAT TRANSFER DESIGN PARAMETERS
CRYOGENIC BATCH REACTOR OPTIMISATION
Section 7 page 259, Simulation Cases
Process
Process fluid assignments to shell side or tube side.
Selection of stream temperature specifications.
Setting shell side and tube side pressure drop design limits.
Setting shell side and tube side velocity limits.
Selection of heat transfer models and fouling coefficients for shell and tube side.
Mechanical
Selection of heat exchanger TEMA layout and number of passes.
Specification of tube parameters - size, layout, pitch and material.
Setting upper and lower design limits on tube length.
Specification of shell parameters – materials, baffle cut, baffle spacing and clearances.
Setting upper and lower design limits on shell diameter, baffle cut and baffle spacing.

5. CRYOGENIC BATCH REACTOR OPTIMISATION
HEAT TRANSFER SHELL AND TUBE TEMA LAYOUTS
CRYOGENIC BATCH REACTOR OPTIMISATION
Section 7 page 245, Appendix IV

6. CRYOGENIC BATCH REACTOR OPTIMISATION
HEAT TRANSFER MODEL SELECTION FLOW CHART
CRYOGENIC BATCH REACTOR OPTIMISATION
Section 7 page 258, Appendix XIV

7. CRYOGENIC BATCH REACTOR OPTIMISATION
HEAT TRANSFER TUBE OR SHELL SIDE FLUID SELECTION
CRYOGENIC BATCH REACTOR OPTIMISATION
Process fluid assignments to shell side or tube side?
Tube side Expensive material of construction
High pressures High fouling potential
Shell side High volume flow rates High viscosity
Heat exchangers for high fouling and high viscosity fluids
Shell and Tube Heat Exchanger Designs
Shell side Helical flow baffles by Lummus
No low velocity zones or bypass flows
Tube side Twisted tubes by Brown Fintube Co
Increase shear
Spiral heat exchanger Plate and frame Plate and Shell

8. CRYOGENIC BATCH REACTOR OPTIMISATION
HEAT TRANSFER CASE 7.04 METHANOL COOLING
CRYOGENIC BATCH REACTOR OPTIMISATION
Section 7 page 270, Case 7.04
Cool kg/h methanol from 95 to 40°C
Coolant brackish water at 25°C maximum return 40°C
Calculated duty 4364 kW water flow required kg/h
Methanol on shell side being the cleanest fluid
Fouling coefficients m2°K/W
Tube side pass 2 Shell side pass 1

9. CRYOGENIC BATCH REACTOR OPTIMISATION
HEAT TRANSFER CASE 7.01 HORIZONTAL CONDENSOR
CRYOGENIC BATCH REACTOR OPTIMISATION
Section 7 page 260, Case 7.01

10. CRYOGENIC BATCH REACTOR OPTIMISATION
HEAT TRANSFER CASE 7.07 EVAPORATIVE COOLING TOWER
CRYOGENIC BATCH REACTOR OPTIMISATION
Section 7 page xxx, Case 7.07 (Edition 3)
A distillation column overhead condenser has a duty of 2740 kW
The condenser design is based on OHTC 50 Btu/h-ft2-°C with HTA 1700 ft2
Cooling water at 102°F is recirculated at kg/h through a fin fan cooler
The tower is simulated using SCDS column in VLE mode with 2 stages
Heat removal is simulated using heat exchanger 120 Btu/h-ft2-°C with HTA 3280 ft2
Inlet air flow is stdV m3/h and humidity is set. Murphree η adjusted to process

11. CRYOGENIC BATCH REACTOR OPTIMISATION
HEAT TRANSFER CASE 7.08 GAS COMPRESSION STATION
CRYOGENIC BATCH REACTOR OPTIMISATION
Section 7 page xxx, Case 7.08 (Edition 3)
Natural gas is compressed from 43 bar at 10°C to 87.2 bar at 72°C
A fin fan air after cooler reduces the temperature to 50°C
The cooler has 1 bay with 2 fans and 2 single pass coils in series with 4 rows
The gas flow is kg/h with MW 18.5 kg/kmol
Air inlet temperature 30°C and outlet temperature 46.2°C at Pa
Mechanical details are entered into the Air Cooler Sizing Tool in Rating Mode

12. CRYOGENIC BATCH REACTOR OPTIMISATION
HEAT TRANSFER CASE 7.09 BITUMEN HEAT EXCHANGER
CRYOGENIC BATCH REACTOR OPTIMISATION
Section 7 page xxx, Case 7.09 (Edition 3)
Design a heat exchanger for 100 te/h bitumen at 140° to be heated to 170°C
Heating fluid Therminol HTO at 270°C with a return temperature of 250°C
Bitumen on the shell side due to high viscosity
Tubes are 1” od with a square pitch of 1.25”
Maximum tube length allowed set at 3 m with no excess design
Fouling tube side W/m2-°K and shell side W/m2-°K

13. CRYOGENIC BATCH REACTOR OPTIMISATION
HEAT TRANSFER CASE 7.10 DOUBLE EFFECT EVAPORATOR
CRYOGENIC BATCH REACTOR OPTIMISATION
Section 7 page xxx, Case 7.10 (Edition 3)
An acetone, water and methyl oleate process stream is separated in a double effect falling film evaporator. The process stream is fed to the second effect in a backward feed mode and the heat input is supplied by steam at 7 bar to the first effect.