Steam & Condensate System AuditFor your tissue machine Yankee dryer�e steam input and condensate removal system is integral to the efficient and effective operation of your Yankee dryer. Its care and upkeep is truly a "hot" topic. Even with a good condensate removal system good performance is not a guarantee. A system audit by Valmet will show the level at which your system is currently operating and provide potentially system saving recommendations.

Identify and address potential problems

Ÿ Better productivity with limited investmentŸ Lower cost per ton producedŸ More systematic way to develop

operations, processes and equipmentŸ Better expert network with ValmetŸ Long-term support by a reliable machinery

and process supplierŸ Quick specialist assistance as needed

e Yankee steam and condensate system is a critical part of the drying process. is system must provide a consistent supply of steam to the Yankee cylinder and then remove the condensate that forms.

Unfortunately, all system components will experience a degradation in condition and performance over time. Also, even a good condensate removal system doesn't guarantee optimal performance if it is incorrectly sized.

Only regular inspections can keep you aware of the operating condition of your Yankee steam and condensate system. Some potential problems that can be detected by system inspections:Ÿ Improper controls adjustments and setpointsŸ Excess energy useŸ Steam erosion and leaksŸ CorrosionŸ Drying problemsŸ Safe operationŸ Inefficient syphon and condensate line sizing

Early detection of these problems and many others can yield tremendous savings in time and money, and possibly prevent harm to operating personnel.Valmet has the staff and equipment to quickly and

Case study - Yankee dryer optimizationA system audit by Valmet uncovered that a mill's Yankee steam system was wasting $160,000/year due to the system's unreliability and inconsistent performance . Valmet recommended a system rebuild for energy savings and operational improvements which included changing the condensate removal system to "velocity control". e condensate removal and dryer pressure control were updated to modern performance, resulting in reliable and consistent system operation. ROI was 2-2.5 years based only on the energy savings.

accurately inspect your Yankee steam system and provide a detailed analysis. e audit makes recommendations for maintaining and improving consistent system performance, as well as identify steam energy savings.

Benefits

Condensate header arrangement of a

modern Yankee dryer

Identify and optimize potentialTo meet this need, Valmet's Air Systems Division technical specialists in the Process Engineering department provide evaluation services on the paper machine dryer section steam and condensate system, dust systems and mill ventilation.

Extensive testing by Valmet of paper machine steam systems and dryer sections has shown that the dryer section represents an opportunity for increased productivity, improved quality and reduced operating costs, oen with a relatively modest capital expenditure.

ese surveys can be limited to one narrow area such as the steam and condensate system, or can be very extensive and include all paper machine air systems, depending on the particular needs of the mill. A yankee steam and condensate system audit will typically require one Valmet expert on site for two days to gather the necessary data, perform calculations and generate the report.

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e-mail: paper.service@valmet.comSpeci�cations in this document are subject to change without notice.Product names in this publication are all trademarks of Valmet Corporation.

For more information, contact your local Valmet office. www.valmet.com

Yankee dryer performance analysisis part of the study provides a complete analysis of paper machine Yankee dryer performance in terms of steam energy use including the analysis of dryer drainage performance and steam system operation.

Review and reportsMeasured data is compiled at the mill site and preliminary major conclusions are drawn. e data and conclusions are reviewed with operating management. Mill preferences for upgrading or resolving problems are obtained at this meeting if not previously established. e data are further analyzed at the Valmet Steam Systems office.

A report will be prepared, which will include the following:Ÿ Conclusions and associated short and long term

recommendations to improve dryer performance with emphasis on operating requirements and energy conservation

Ÿ Operation suggestions for improvement in maintenance

Ÿ Implications of the operation of the steam system with a new Yankee dryer syphon

Ÿ Cost/bene�t calculations for all major recommendations, if applicable

Ÿ Suggested implementation sequence for capital and non-capital recommendations

Ÿ Summary of all paper machine data collected by Valmet

Yankee syphon straw velocity (m/sec)

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Calculated operating point

Good syphonperformance

Measuredoperating point

Example yankee rotary syphon velocity performance graph from a steam & condensate audit.

e following areas are studied and compared to standard performance levels:Ÿ Yankee Dryer steam consumptionŸ Steam energy consumption and efficiencyŸ Steam and condensate system design and

performanceŸ Steam and condensate line sizingŸ ermocompressor performance evaluationŸ Condensate handling efficiency and syphon

performance and sizingŸ Future steam system performance requirements and

recommended system changesŸ Yankee dryer surface temperature readings

(depending on accessibility)