Condensate Management Monitoring Condensate

Transcription

1 Condensate Management Monitoring Condensate Virginia Durham May 2008 Weyerhaeuser_October

2 Outline Goals in condensate management Monitoring Purpose Sampling Testing Major Streams Contaminants Automatic dump systems Weyerhaeuser_October

3 Condensate Management Maximize quantity returned Energy value Maximize quality Boiler reliability (Condensate system reliability) Weyerhaeuser_October

4 The cost of lost condensate 1 GPM: $4300 per year 20 GPM: $1600 per week ($85,000/year) in boiler fuel cost Assuming : $6/mmBTU fuel cost 80 % boiler efficiency 200 degf condensate 70 degf make-up water Weyerhaeuser_October

5 Goal: Monitoring Condensate Quality Maximize condensate quantity and quality to provide economy and boiler protection Contamination detection Treatment program monitoring and control Polisher performance monitoring and control Condensate stream return control Weyerhaeuser_October

6 Condensate quality TAPPI Guidelines Parameter High purity Water system Softened water system (pressure dependent) Total Hardness Non -detectable ppm Silica <.1 ppm Iron <.01 ppm ppm Copper Conductivity <.01 ppm 5 mmhos above expected 30 mmhos From : TAPPI Tips Weyerhaeuser_October

7 Sampling How? Stainless steel sample line Maintain adequate velocity/minimize line length Run sample continuously Cool sample Follow ASTM D3370 Weyerhaeuser_October

8 Routine Sampling Sampling Where? Critical streams Composite streams prior to flash tanks/vented receivers Bulk condensate return streams Non-routine Paper machine receivers Other? Weyerhaeuser_October

9 Example Condensate System Makeup Steam Deaerator Resin Polisher Feedwater Boilers Turbine Generator Magnetic Filter Return Condensate evaporators Digester Paper Machine Pulp Dryer Weyerhaeuser_October

10 Tests ph Metals Testing Corrosion Coupons Conductivity Silica Hardness Oxygen Testing Purpose Program Chemistry/ Program Performance (Contamination) Program Performance Continuous : (Wet analysis, Sub-micron Filtration) Continuous: (Turbidimeters, Particle Counters) Continuous (Continuous) Typical Method Weyerhaeuser_October

11 Tests ph Metals Testing Corrosion Coupons Conductivity Silica Hardness Oxygen Testing Purpose Program Chemistry/ Program Performance (Contamination) Program Performance Continuous : (Wet analysis, Sub-micron Filtration) Continuous: (Turbidimeters, Particle Counters) Continuous (Continuous) Typical Method Weyerhaeuser_October

12 ph Testing Cool sample to 77 o F Avoid loss of volatile species Accurate ph measurement Weyerhaeuser_October

13 Effect of Temperature on Sample ph Sample ph Sample Temperature (Degrees F) Weyerhaeuser_October

14 Temperature compensation of ph Some meters have 2 levels of compensation: electronic solution chemistry Many meters simply address the electronic compensation and do not compensate for temperature effects on solution chemistry Weyerhaeuser_October

15 Sample point location for ph testing Be sure sample points provide meaningful results Challenging for systems with high alkalinity make up water Weyerhaeuser_October

16 Paper Machine wet end dryers main section dryers third section heat exchanger main receiver vacuum pump Weyerhaeuser_October

17 Tests ph Metals Testing Corrosion Coupons Conductivity Silica Hardness Oxygen Testing Purpose Program Chemistry/ Program Performance (Contamination) Program Performance Continuous : (Wet analysis, Sub-micron Filtration) Continuous: (Turbidimeters, Particle Counters) Continuous (Continuous) Typical Method Weyerhaeuser_October

18 Metals Testing Wet chemistry iron copper Sub-micron filtration Continuous Turbidity Particle Counters Weyerhaeuser_October

19 Sub-micron Filtration Example of iron on a paper machine startup Weyerhaeuser_October

20 Turbidity monitoring Indicator of particulate corrosion products Can be used for automatic diversion of condensate Correlation of turbidity with contamination levels is required Weyerhaeuser_October

21 Turbidity Monitoring Turbidity Meter Condensate Cooler Sample Dumped Condensate To Power House Weyerhaeuser_October

22 Tests ph Metals Testing Corrosion Coupons Conductivity Silica Hardness Oxygen Testing Purpose Program Chemistry/ Program Performance (Contamination) Program Performance Continuous : (Wet analysis, Sub-micron Filtration) Continuous: (Turbidimeters, Particle Counters) Continuous (Continuous) Typical Method Weyerhaeuser_October

23 Conductivity Monitoring Typically used as an indication of raw water and liquor contamination Portable meters are a good tool Continuous monitoring is a critical component to a boiler protection program Weyerhaeuser_October

24 Conductivity Monitoring Conductivity Probe Condensate Sample Cooler Conductivity Meter Dumped Condensate To Power House Weyerhaeuser_October

25 Automatic conductivity dumps considerations Location of probe Dead time be sure that probe/meter can detect and divert condensate before contaminants reach the valve Set point point for dumping Low enough to catch intrusion while avoiding nuisance alarms Preventive maintenance Exercise the probe, meter, and the valves. Weyerhaeuser_October

26 Conductivity Monitoring Minimize dead time: Line length and sample flow Condensate Cooler Conductivity Probe Conductivity Meter Sample Dumped Condensate To Power House Weyerhaeuser_October

27 Conductivity Monitoring Condensate Cooler Conductivity Probe Conductivity Meter Set Point for dumping: Low enough for protection Sample Dumped Condensate To Power House Weyerhaeuser_October

28 Conductivity Monitoring Conductivity Probe Condensate Sample Cooler Conductivity Meter Preventive Maintenance: Exercise the valve Dumped Condensate To Power House Weyerhaeuser_October

29 Automatic conductivity dumps considerations Location of probe Dead time be sure that probe/meter can detect and divert condensate before contaminants reach the valve Set point point for dumping Low enough to catch intrusion while avoiding nuisance alarms Preventive maintenance Exercise the probe, meter, and the valves. Weyerhaeuser_October

30 Tests ph Metals Testing Corrosion Coupons Conductivity Silica Hardness Oxygen Testing Purpose Program Chemistry/ Program Performance (Contamination) Program Performance Continuous : (Wet analysis, Sub-micron Filtration) Continuous: (Turbidimeters, Particle Counters) Continuous (Continuous) Typical Method Weyerhaeuser_October

31 Spectrophotometer Low level hardness testing Silica Wet testing for iron, copper Weyerhaeuser_October

32 Oxygen Testing Used typically as a troubleshooting tool in condensate Continuous Weyerhaeuser_October

33 Oxygen Testing Weyerhaeuser_October

34 Typical Routine Monitoring Tests ph Metals Testing Corrosion Coupons Conductivity Silica Hardness Oxygen Purpose Program Chemistry/ Program Performance (Contamination) Program Performance Continuous : (Wet analysis, Sub-micron Filtration) Continuous: (Turbidimeters, Particle Counters) Continuous (Continuous) Typical Method Weyerhaeuser_October

35 Test Sensitivity Issues Set-point for dumping on conductivity Choice of hardness test Use spectrophotometer Silica/hardness test more sensitive than conductivity for raw water intrusion Is conductivity sensitive enough for low level acid intrusion from Chlorine dioxide generator? Weyerhaeuser_October

36 Major Streams and their Contaminants Steam Makeup Deaerator Resin Polisher Feedwater Boilers Turbine Generator Magnetic Filter Return Condensate evaporators Digester Paper Machine Pulp Dryer Weyerhaeuser_October

37 Streams Paper Machine Evaporators/ Concentrators Digester Liquor Heaters Major Streams Major Contaminant Corrosion Products (Iron) Liquor Liquor Minor Contaminants Mill Water Corrosion Products Corrosion Products Pulp Dryer Corrosion Products (Copper) Corrosion Products (Iron) Chlorine Dioxide Generator Condensers/Mill Water Heaters Lube Oil System Glycol System Acid Mill Water Oil Glycol Corrosion Products Corrosion Products Corrosion Products Corrosion Products Weyerhaeuser_October

38 Boiler protection though automatic dump systems Stream Paper machine Evaporator Digester Chlorine Dioxide Generator Other streams with possible liquor, raw water contamination Meter/Dump System Turbidity, (Conductivity) Conductivity Conductivity Conductivity, (ph) Conductivity Weyerhaeuser_October

39 Dumping Practices Automatic Systems - preventive maintenance Full testing of system Frequency? Optimization Opportunity? Allow polishers/filters to do more work Requires a rigorous study of polisher system performance during upset conditions to avoid risk to boiler Ongoing monitoring of polisher system effluent must be in place Monitoring of flows Continuous Walk-downs Also provides information on leaks Weyerhaeuser_October

40 Summary Condensate monitoring program is critical for boiler protection Test method sensitivity should be considered when monitoring for contamination Maintenance and configuration of dump systems require attention to assure protection Look closely at polisher/filter operation and potential to return more condensate Weyerhaeuser_October

41 Thank You Weyerhaeuser_October