1. Bryan PicouJames Roberts Advisor: Dr. Junkun Ma ET 494 Instructor : Dr. Cris Koutsougeras Evaporator Optimization Project

2. Domino Sugar Refinery is in Arabi, La Produce 8 million pounds of sugar per day on average It is the third largest sugar refinery in the world

3. Evaporator Optimization Project Steam is one of the most expensive resources for a refinery Take the current operation of the evaporators and make it more efficient Take the current operation of the melters and eliminate the steam

4. Evaporators Evaporator uses steam in a vacuum to heat the sugar liquor and lower its density Left over vapors from this process is what we are trying to optimize

5. Melter Takes the raw sugar and uses steam to melt this sugar into a liquid. It uses direct steam injection Vapors from evaporator will be rerouted to power the melter

6. Current Operation

8. Sugar Parameters Based upon 8 million pound melt rate 8 % scrap rate Sugar going into melters assuming 70 Brix

9. Sketch of Phase 1

10. Energy required to Melt Sugar Q= Specific Heat * Mass of Sugar * ΔTemperature Q=0.65 BTU/lb F * 478,800 lb/hr * (165 F-130 F) Q=10,892,700 Btu/hr

11. Barometric Condenser

12. Condenser Design Q steam = Q sugar Mass of Steam * Latent Heat of Steam = C p of Sugar * Mass of Sugar * Δ Temperature Rearranging: Mass Steam = (C p of Sugar * Mass of Sugar * Δ temperature)/Latent Heat of Steam

13. Steam With Phase Change Qsugar = Mass of Steam * Latent Heat of Steam 10,892,700 BTU/hr = m * 922.6 BTU/lb Mass of Steam = 11,806.525 lb/hr

14. Sugar going to Condenser Q steam = Mass * Specific Heat * Δ Temperature 10,892,700 BTU/hr = m * 0.65 BTU/lb F * (188.421 F – 165 F) M = 715,511.72 lb/hr M = 1079.6 gpm

15. Steam Pipeline Head loss H L = f * (L/D) * (V 2 /2g) H L = 0.015 * (341/24) * (67.51 2 /2*32.2) H L = 180.97

16. Steam Pipeline Design Babcock Formula Δp = 0.47 * (d+3.6/d^6) * m^2 * L * v Δp = 0.47 * (24+3.6/24^6) * 4.436^2 * 522 * 42.16 Δp = 0.0294 psia Δp = 0.33%

17. Steam Pipeline Mach Number Mach Number = Velocity / Sonic Velocity Mach Number = 84.5 ft/s / 1528.09 ft/s Mach Number = 0.056

18. 24” Steam Pipeline Velocity = Volumetric flow Rate / Cross-Sectional Area of pipe V in = 763,077.9 ft^3/hr / 3.14 ft^2 V in = 67.51 ft/s V out = 766,173 ft^3/hr / 3.14 ft^2 V out = 84.5 ft/s

19. Sugar Pipeline Design Volumetric Flow Rate = Velocity * Area Velocity = Volumetric Flow Rate/Area Volumetric Flow Rate of Sugar = 150,949.436 * (1/92.2) = 1637.196 ft 3 /hr Area of 4 in pipe = 0.0872 ft 2 Velocity = 5.214 ft/s

20. Residence Time λ = Volume of Melter / Volumetric Flow Rate Volume of Melter = 329.867 ft 3 Volumetric Flow Rate = 2884.34 ft 3 /hr λ = 6.86 min

21. Residence Time Residence Time with South Melter λ = 10.29 min

22. Sugar Dissolution Lab

23. Adding a Melter the same size Theoretical Temperature = 246.75 * x -0.173 Theoretical Temperature = 246.75 * 13.72 -0.173 Theoretical Temperature = 156.85 F

24. Residence Time with New Melter λ = 13.72 min This extra melter would give the sugar an extra 33.24% more residence time than theoretically needed

25. Heat Exchangers Δp in HX#1 to HX#2 = Inlet from G5 pump – Inlet of HX #2 Δp in HX#1 to HX#2 = 47.39 psia – 41.39 psia Δp in HX#1 to HX#2 = 6 psia Approach Temperature

26. 3 Pumps P 1 / γ 1 + Z 1 + V 1 2 /2g – h L + h A = P 2 / γ 2 + Z 2 + V 2 2 /2g Condenser Pump h L = 2.48 ft h A = 10 psia

27. Pipelines V = Q/A Melter Recirculation Pipeline (8”) V = 8659.33 ft^3 / (0.349 *3600) V = 6.89 ft/sec

28. Steam Pipeline Supports F = E * I * π ^2 / K * L^2 F = 29000000 psi * 28.09 in^4 * π ^2 / 2 * 420^2 in^2 F = 22,788.8 lb

29. Deflection Y = W * L^3/ 3 * E * I Deflection of I beam Y = 1904.26 lb * 20^3 in ^3/ 3 * 29000000 psi * 127.7 in^4 Y = 0.00137 in

30. Bolts (5/8”) σ = F/A σ = 9427 psi σ = 9427 psi/4 Bolts σ = 2356.7 psi / Bolt

31. Clevis Hangers σ = F/πr^2 24” Steam Pipeline R = 1904.26 / π * 18000 R = 0.183 in Diameter = 0.367 in

32. Condenser Supports (Stress) σ = W * L / Z σ = 17,314 lb * 109 in / 91.3 in^4 σ = 20,671.79 psi

33. Thermal Expansion ΔL = L o * α * ΔT Steam Pipeline ΔL = 3.96 in

34. Evaporators M si L si + M Li L Li = M so L so + M so L so 4A Evaporator M si = (11.81 * 1141.4)+(476.35*107.5)- (488.16*104.8)/949.7 M si = 14.24 kpph

35. Evaporators Density of Liquor Exiting = Mass of Feed liquor * Density of Feed Liquor / Mass of Exiting Liquor Density = 488.16 kpph * 64.4 Brix / 476.35 kpph Density = 65.996 Brix

36. Evaporators Exiting Temperature of Liquor = Boiling Point Rise + Steam Temperature Exiting Temperature = 7.056 + 188.58 Exiting Temperature = 195.64 F

37. Phase 2

38. Heat Exchanger Q = U *A * ΔT LM UA = Q * ΔT LM Current Operation UA = 149,103.6 Evaporator Optimization Project UA = 149,943.9

39. Savings Phase 1 $/year = (12,000 lb/hr * 986.2 BTU/lb / 79.5% Boiler Efficiency) * 24 hrs * ($3.73/1,000,000 BTU) * 260 days $/year = 346,734.88

40. Savings Phase 2 $/year = (2,600 lb/hr * 949.6 BTU/lb / 79.5% Boiler Efficiency) * 24 hrs * ($3.73/1,000,000 BTU) * 260 days $/year = 72,283.70

41. Savings Combined $/year = 419,072.69

42. Prices Phase 1 Total Cost = $1,205,105.29 (+/- 15%) Phase 2 Total Cost = $221,429.38 (+/- 15%) Combined Total Cost = $1,426,534.67 (+/- 15%)

43. Return on Investment Phase 1 ROI = 3.48 years Phase 2 ROI = 3.06 years Combined ROI = 3.41 years

44. Further Research Eliminating Steam to Saturators

45. Final Proposal

46. References Domino Sugar Corporation Cane Sugar Refining Handbook www.sugartech.co.za