1. Understanding Steam Efficiency IPPTA Conference Kolkata March 2016 Rob Parker – Kadant Johnson

2. Steam – What we all know It’s hot! It’s expensive! We need it ……a lot of it!

3. Steam – Usage Major Energy Consumer in Paper Machine Conservation of Steam Use is Key to Competitiveness Usage must be measured Usage must be controlled

4. Steam – Usage “You can't control what you can't measure” Tom DeMarco Controlling Software Projects, Management Measurement & Estimation (1982), p. 3 What is actually being measured? What does it mean? How can it be controlled?

5. Steam – Specific Steam Consumption T Steam / T Paper Key indicator for monitoring efficiency All mills have a figure or range Easily available …..Simple?

6. Steam – Specific Steam Consumption Consider the Variables: Measured Energy Value: All steam supplied to the machine Fuel mass used at boiler x boiler efficiency Steam supplied only to the dryer section Measured Production Value: Finished Paper Throughput Pope Reel Throughput

7. Steam – Specific Steam Consumption Consider the Time Period: Daily Average Monthly Average Sheet-On Stable Production

8. Steam – Specific Steam Consumption Consider the Moisture: Press moisture affects steam consumption significantly 1% moisture increase = up to 5% steam increase Analyse steam consumption compared to H 2 O evaporated for meaningful benchmarking

9. Steam – Benchmarking Moisture Ratio: (% Dry Out / % Dry In) – 1 EG. Kraftmill, 93% Popereel, 49% Press (93 / 49) – 1 = 0.89 T Steam / T H 2 O Evap

10. Steam – Benchmarking Good level for steam consumption / water evaporated: 1.35 EG. Same Kraftmill – 1.35 x 0.89 = 1.20 T / T Paper @ 100% efficiency, m/c draw, sheet-on, dryers only T Steam / T H 2 O Evap

11. Steam – Benchmarking For sized grades there are different considerations: 75gsm sized copier grade, size application of 2gsm @ 7% solids 3.5m wide sheet, 500m/min Press Dryness 43.0% Pre-Size Press 95.0% Sheet Weight – 73gsm Exit Size Press70.2% Pope95.0% Sheet Weight – 75gsm T Steam / T H 2 O Evap

12. Steam – Benchmarking Production rate for each section should be calculated: Pre-dryer 73gsm x 3.5m x 500m/min = 7665 kg/hr Post-dryer 75gsm x 3.5m x 500m/min = 7875 kg/hr T Steam / T H 2 O Evap

13. Steam – Benchmarking Evaporation rate for each section should be calculated: Pre-dryer (95 / 43) - 1 = 1.21 7665 kg/hr x 1.21 = 9275 kg/hr H20 Evaporated Post-dryer (95/70.2) – 1 = 0.35 7875 kg/hr x 0.35 = 2756 kg/hr H2O Evaporated T Steam / T H 2 O Evap

14. Steam – Benchmarking Evaporation rate for each section should be calculated: Pre-dryer (95 / 43) - 1 = 1.21 7665 kg/hr x 1.21 = 9275 kg/hr H20 Evaporated Post-dryer (95/70.2) – 1 = 0.35 7875 kg/hr x 0.35 = 2756 kg/hr H2O Evaporated T Steam / T H 2 O Evap

15. Steam – Benchmarking Total machine evaporation = 12031 kg/hr At 1.35 T Steam / T H2O Evap = 16242 kg/hr Divided by machine production of 7875kg/hr Good Consumption: 2.06 T Steam / T Paper @ 100% efficiency, m/c draw, sheet-on, dryers only T Steam / T H 2 O Evap

16. Steam – Benchmarking Steam consumption for dryers only is benchmarked If < 1.35, other inefficiencies should be targeted. If > 1.35, steam and condensate system needs to be examined T Steam / T H 2 O Evap

17. Steam – Benchmarking Also monitor: Press Performance – samples to TAPPI standards % Downtime (sheet breaks) % Downtime (shuts/breakdowns) %Finishing Losses Steam flows to ancillary users – PV system, Starch Cooking, Silo Heating

18. Steam – Flow Measurement Accuracy Check Points: Orifice Plate Installation Flow Transmitter Installation Orifice Plate Specification Density Compensation Correct Steam Quality

19. Steam – Flow Measurement Accuracy Check Points: Orifice Plate Installation Flow Transmitter Installation Orifice Plate Specification Density Compensation Correct Steam Quality

20. Steam – Flow Measurement Accuracy Check Points: Orifice Plate Installation Flow Transmitter Installation Orifice Plate Specification Density Compensation Correct Steam Quality

21. Steam – Flow Measurement Accuracy Check Points: Orifice Plate Installation Flow Transmitter Installation Orifice Plate Specification Density Compensation Correct Steam Quality

22. Steam – Flow Measurement Accuracy Check Points: Orifice Plate Installation Flow Transmitter Installation Orifice Plate Specification Density Compensation Correct Steam Quality

23. Steam – Reducing Usage in System Flash Steam and Heat Recovery Minimise Number of Dryers Draining to Condenser Install Stationary Syphons Minimise Venting to Condenser Eliminate Traps blowing to drain Ensure Dry Steam in Supply Good Pipe Insulation Also……condensate return, condense and return to boiler house!

24. Steam – Flash Steam Recovery Example >800TPD linerboard machine 7 bar(G) in dryers No flash recovery – venting to overloaded condenser Installed flash recovery vessel Use flash in steam box Around 5% saving in steam consumption

25. Steam – Flash Steam Recovery Example <300TPD kraft machine <3 bar(G) in dryers Lots of vented steam due to passing steam traps Heat transfer for drying is very good Installed dP style system with stationary syphons Installed flash recovery systems Steam consumption reduced >10%

26. Steam – Conclusion Measure Accurately Benchmark Consistently Target Problems Effectively Reduce and Control Usage

27. Understanding Steam Efficiency