column_design

General functional algorithms for the design and purchase cost estimation of distillation columns.

References

[1] (1,2,3,4,5,6,7)

Seider, W. D., Lewin, D. R., Seader, J. D., Widagdo, S., Gani, R., & Ng, M. K. (2017). Product and Process Design Principles. Wiley. Cost Accounting and Capital Cost Estimation (Chapter 16)

[2]

M. Duss, R. Taylor. (2018) Predict Distillation Tray Efficiency. AICHE

[3] (1,2,3,4,5,6)

Green, D. W. Distillation. In Perry’s Chemical Engineers’ 674 Handbook, 9 ed.; McGraw-Hill Education, 2018.

compute_purchase_cost_of_trays(N_T, Di)

Return total cost of all trays at BioSTEAM’s CEPCI.

Parameters:

• N_T (int) – Number of trays.

• Di (float) – Inner diameter [ft].

Notes

The purchase cost is given by [1]. See source code for details. The purchase cost is scaled according to BioSTEAM’s Chemical Plant Cost Index, biosteam.CE.

compute_empty_tower_cost(W)

Return the cost [C_V; in USD] of an empty tower vessel at BioSTEAM’s CEPCI.

Parameters:

W (float) – Weight [lb].

Notes

The purchase cost is given by [1]. See source code for details.

compute_plaform_ladder_cost(Di, L)

Return the cost [C_PL; in USD] of platforms and ladders at BioSTEAM’s CEPCI.

Parameters:

• Di (float) – Inner diameter [ft].

• L (float) – Legnth [ft].

Notes

The purchase cost is given by [1]. See source code for details.

compute_tower_weight(Di, L, tv, rho_M)

Return the weight [W; in lb] of the tower assuming 2:1 elliptical head.

Parameters:

• Di (float) – Inner diameter [ft].

• L (float) – Legnth [ft].

• tv (float) – Shell thickness [in].

• rho_M (floa) – Density of material [lb/in^3].

Notes

The tower weight is given by [1]. See source code for details.

compute_tower_wall_thickness(Po, Di, L, S=15000.0, E=None, M=29.5)

Return the wall thinkness [tv; in inches] designed to withstand the internal pressure and the wind/earthquake load at the bottom.

Parameters:

• Po (float) – Operating internal pressure [psi].

• Di (float) – Internal diameter [ft].

• L (float) – Height [ft].

• S (float) – Maximum stress [psi].

• E (float) – Fractional weld efficiency

• M (float) – Elasticity [psi].

Notes

The wall thickness is given by [1]. See source code for details.

Warning

This function is only applicable to positive internal pressures (no vacuums). Vacuum pressure vessels may require stiffening rings and higher vessel thickness.

compute_tray_base_purchase_cost(Di)

Return the base cost of a tray [C_BT; USD] at a CE of 500.

Parameters:

Di (float) – Inner diameter [ft].

Notes

The purchase cost is given by [1]. See source code for details.

compute_n_trays_factor(N_T)

Return the cost factor for number of trays, F_NT.

Parameters:

N_T (Number of trays)

Notes

The cost factor is given by [1]. See source code for details.

compute_murphree_stage_efficiency(mu, alpha, L, V)

Return the sectional murphree efficiency, E_mv.

Parameters:

• mu (float) – Viscosity [mPa*s]

• alpha (float) – Relative volatility.

• L (float) – Liquid flow rate by mol.

• V (float) – Vapor flow rate by mol.

Notes

The efficiency is given by [2]. See source code for details.

compute_flow_parameter(L, V, rho_V, rho_L)

Return the flow parameter, F_LV.

Parameters:

• L (float) – Liquid flow rate by mass.

• V (float) – Vapor flow rate by mass.

• rho_V (float) – Vapor density.

• rho_L (float) – Liquid density.

Notes

The flow parameter is given by [3]. See source code for details.

compute_max_capacity_parameter(TS, F_LV)

Return the maximum capacity parameter before flooding [C_sbf; in m/s].

Parameters:

• TS (float) – Tray spacing [mm].

• F_LV (float) – Flow parameter.

Notes

The max capacity parameter is given by [3]. See source code for details.

compute_max_vapor_velocity(C_sbf, sigma, rho_L, rho_V, F_F, A_ha)

Return the maximum allowable vapor velocity through the net area of flow before flooding [U_f; in m/s].

Parameters:

• C_sbf – Maximum Capacity Parameter (m/s)

• sigma – Liquid surface tension (dyn/cm)

• rho_L – Liquid density

• rho_V – Vapor density

• F_F – Foaming factor

• A_ha – Ratio of open area, A_h, to active area, A_a.

Notes

The max vapor velocity is given by [3]. See source code for details.

compute_downcomer_area_fraction(F_LV)

Return the ratio of downcomer area to net (total) area, A_dn.

Parameters:

F_LV (float) – Flow parameter.

Notes

The fraction of downcomer area is given by [3]. See source code for details.

compute_tower_diameter(V_vol, U_f, f, A_dn)

Return tower diameter [D_T; in meter].

Parameters:

• V_vol (float) – Vapor volumetric flow rate [m^3/s].

• U_f (float) – Maximum vapor velocity before flooding [m/s].

• f (float) – Ratio of actual velocity to U_f.

• A_dn (float) – Ratio of downcomer area to net (total) area.

Notes

The tower diameter is given by [3]. See source code for details.

compute_tower_height(TS, N_stages, top=True, bottom=True)

Return the height of a tower [H; in meter].

Parameters:

• TS (float) – Tray spacing [mm].

• N_stages (float) – Number of stages.

Notes

The tower height is given by [3]. See source code for details.