Driving Toward Energy Efficiency

1. Steam Driving Toward Energy Efficiency Emerson Process Management Novaspect. Inc. June 22 / 23, 2010

2. Steam – Take a System Approach

3. Topics Insulation Pressure Reduction Flash Recovery / Cascade Systems Steam Trapping & Steam Trap Management Steam Leak Detection & Repair Air Venting Steam Using Process Equipment Steam Tracing Atmospheric Flash Tanks / Flash Condensing Condensate Return

4. Note •Today’s presentation is efficiency centric. •Historically, projects have not been driven solely on energy savings. •Other drivers include: -Safety -Throughput -Reliability / Maintenance

5. What Do You Want to Know & Why (Monitoring Points / Value) • You can’t manage or control what you don’t measure • -Typically steam systems are under measured • Typical measurement points serve to determine where the steam goes, how • much is being used, determine where losses are occurring and to help troubleshoot system issues. • -In steam using process equipment, temperature and ΔP measurements lead to informed process and efficiency improvement decisions. • -In the distribution / condensate return system the ΔP is the condensate driver; flow and temperature measurement let you monitor and put a value to the energy being returned back to the boiler.

6. Assumptions / Clarifications •Cost of Steam •Definitions -Sensible Heat: Btu’s contained in liquid -Latent Heat: Btu’s gained at vaporization and given up at condensation -Superheat: Btu’s over and above those gained at the at vaporization – generally measured as temperature above that of saturated steam

7. Cost Savings through Steam Efficiency

8. Insulation Prevention of radiant heat loss (condensing of steam) 100 PSIG Steam, 100’ 8”, Schedule 40 Pipe, 10 MPH Wind Speed, 40°F •Uninsulated Pipe -415 PPH Condensate / 365,700.9 Btu/HR -$32,337 Annual Cost •Insulated Pipe (2” Calcium Silicate) -19.1 PPH Condensate / 17,097.4 Btu/HR -$1,512 Annual Cost / $30,825 Annual Savings -Approximate Payback = 36 days based an installed insulation cost of $3,000; 71 days based an installed insulation cost of $6,000

9. Insulation Prevention of radiant heat loss (condensing of steam) 100 PSIG Steam, 100’ 8”, Schedule 40 Pipe, 0 MPH Wind Speed, 70°F •Uninsulated Pipe -206 PPH Condensate / 181,654 Btu/HR -$16,063 Annual Cost •Insulated Pipe (2” Calcium Silicate) -19.8 PPH Condensate / 17,426 BTU -$1,541 Annual Cost / $14,522 Annual Savings -Approximate Payback = 75 days based an installed insulation cost of $3,000; 151 days based an installed insulation cost of $6,000

10. Pressure Reduction • Ideally, you would produce steam at the pressure you need at the location it’s required in the quantity needed… • •Higher pressure generation • -Smaller Pipe Diameter • -Superheated Steam • -Need for pressure reduction • •Do work during the reduction process • -Generate electricity, compress air • •Elimination of superheat (process fouling) • -Latent heat transfer

11. Flash Recovery / Cascade Systems • Condensate from higher pressure system sent to steam trap(s). • Traps discharge into a vessel that is regulated at a pressure slightly above the lower pressure steam system. • The portion of the condensate that “flashes” into steam is recovered into the lower pressure system. • Lower pressure system requirements not met by the flash recovery / cascade system are supplied through supplemental let down and / or lower pressure steam production. • This allows for multiple uses of each pound of generated steam

12. Flash Recovery / Cascade Systems Value

13. Steam Trapping Where: -Every 100-150’, before rise, after fall, before control valve, at end of line, at steam using process equipment as appropriate. Why: -Condensate removal / maximum Btu latent heat per pound of steam -Reliability (hydraulic shock, cutting valves / components) -System Start Up

14. Steam Trapping – Trap Efficiency

15. Steam Trap Management

16. Steam Leak Detection & Repair 100 PSIG Steam / 100 PSID

17. Air Venting Removal of entrained air or inert gasses. - Insulator / inefficient heat transfer medium - % by volume leads to reduced BTU availability Tell-tale -Temperature reduction Secondary Benefits -Reduction of probability of hydraulic shock -Reduction of temperature stratification (process)

18. •Use the lowest pressure that will meet the process needs. Steam Using Process Equipment

19. Steam Using Process Equipment •Use of saturated steam for process heat exchange. •50°F of superheat results in an additional 29 Btu per LB, or .58 Btu per degree of temperature. •The process has to shed temperature (at .58 Btu per degree) before it gets to the point of latent heat transfer by condensing at saturation temperature.

20. Steam Using Process Equipment •Complete condensate drainage of heat exchange equipment -Steam Trap -Other condensate drainage method

21. Steam Tracing •Seasonal isolation of manifolds. -Automated drainage scheme •Installation best practices to ensure maximum heat transfer. -Insulated, heat transfer cement, no air gaps •Pay attention to ΔP across traps. -Follow maximum tracing run guidelines •Sensible heat for low demand / non-critical tracing. -Instrument & instrument enclosures •Segment Tracing Application Specifications Based on Criticality.

22. Atmospheric Flash Tanks / Flash Condensing •Every Btu counts -“Waste Heat” vs. pre-heat of BFW, freeze protection -Reduced flash venting -More warm condensate returned for reuse •Wrapped tubing, pipe in pipe heat exchanger, plate & frame HX

23. Condensate Recovery • Rule of Thumb Best Practice: • Minimum 7 turns of BFW, 13% Make-up • Recovery of water, treatment costs, sensible heat value coupled with cost avoidance (sewage / treatment). • How • ΔP as motive • Local vented receiver with electric or secondary motive pressure pumps

24. Condensate Recovery - Value

25. Condensate Recovery - Value

26. Next Steps Take Action on Previously Identified Opportunities Steam System Audit -Leak Survey -Insulation Survey -Information “White Space” Process Audit Steam Trap Survey Identify Low Hanging Fruit Identify Costs / Losses / ROI Prioritize Act

27. Questions