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Andritz sets out new Yankee life cycle scheme

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Andritz sets out new Yankee life cycle scheme

September 29, 2014 - 08:36

BRUSSELS, Sept 1, 2014 (PPI Magazine) -Andritz has made a reputable name for itself in the production and supply of Yankee cylinders for various grades, and particularly for tissue and specialty paper.

The Austrian company is now offering a complete life cycle management package to go along with the installation of its Yankee cylinders. PPI spoke to Erwin Walcher, director of Yankee Service for Andritz, about the new life cycle scheme.

PPI: Can you explain why Andritz is offering the new life cycle scheme?

Walcher: Suppliers often provide only single Yankee service components like grinding or leave the customer - after purchase -"alone" with the Yankee. This is a pity as a well maintained Yankee offers a high potential for improved runability and efficient production - a remarkable competitive advantage for the customer. With the Yankee life cycle management (LCM) Andritz focuses on the overall added value of Yankees: from calculation, to manufacturing, coating (PrimeCoat Stratos), operation and optimization. To conclude: Andritz is one of the few suppliers being able to offer to customers' a life-time forecast of their Yankees. This is possible due to our experience in Yankee development and manufacturing that is done solely within Andritz - all out of one hand.

Within the last years Andritz has become the market leader for large and wide steel Yankees as those Yankees are manufactured only in Andritz workshops. It was just a question of time before we developed our own grinding and metalizing process as well, to offer the complete range of manufacturing and service possibilities. But Yankee service comprises more than that: it starts being next to the customer, ready to act. It starts with customized solutions for new Yankees and rebuilds and then escorts the customer through the complete Yankee life cycle.

What ultimate benefits will it bring to Yankee cylinder customers?

As a machine supplier being able to offer complete lines for tissue, paper, board and special paper production, Andritz experts do not see the Yankee as a stand-alone solution but in its "complete environment". Having supplied and started-up several hundred hoods worldwide, Andritz has a vast experience in the area of drying; it is its daily business.

In the course of the life cycle management package the Yankee is analyzed and maintained in its interaction with other key components like condensate removal system, press, etc. The life cycle management service is valid not only for steel Yankees, but for cast Yankees as well - no matter if tissue, paper, MG-paper or tobacco; no matter what brand, no matter if old or new.

Can you give some examples of what the life cycle scheme will cover?

Life cycle management comprises service activities and local support from the start of purchase/rebuild negotiation to the long-term operation of the Yankee. The whole package includes engineering, manufacturing, logistics, start-up support, on-site service (like grinding, coating, on the run measurements, leakage repair, bearing change, even welding are possible and developed), maintenance, analysis (like FE analysis) and diagnostics.

The service package in detail:

1. Mechanical on-site services

a. Grinding of the Yankee

b. Metalizing

c. Spot repair

d. Upgrade and repair of the internal parts

2. Safety and risk management

a. Life time calculation of the Yankee

b. Inspections like ultrasonic, metallurgical and acoustic measurement (replaces in many countries the frequent requested hydrostatic test)

c. Services requested by the major insurance companies

3. Logistic and engineering

a. Customized solutions for replacements

b. On site assembly to avoid transportation restrictions

c. On site welding for large Yankees up to 22-ft diameter

d. Seeing the complete picture: not only focusing on the Yankee but on the steam and condensate system, on the doctors, the right coating application, press concepts, etc.

4. Performance and consulting

For example, calculation of the drying limit of the machine, evaluation of the machine's performance and runability potential in respect of drying costs. Andritz has developed a resource management system (RMS) to analyze and monitor energy consumption and costs of the complete plant.

5. Troubleshooting

In case of any problems the Andritz experts are able to find solutions covering not only the mechanical side such as Yankee surface and Yankee internal inspections but also control logic issues of the steam and condensate system as well as automation issues. 

Additionally the dewatering rate can be checked and compared with the designed optimum running conditions. 

As Andritz understands its service covers the whole process even runnability issues caused by coating chemicals, steam and condensate chemical treatment or Yankee doctor issues can be fast detected and solved.

6. Diagnostic and analysis

For example, on the run measurements to check the Yankee's shape and temperature profile to find the right time for regrinding and metalizing. Crowing issues can be measured and solved. The operation of the condensate removal system can measured during regular operation.

As a real highlight Andritz is also able to measure the thickness and evenness of the organic coating. This helps to optimize it and to save money.

Will it extend the working life of a Yankee cylinder, and if so, by how much?

A Yankee's lifetime is influenced by several aspects, namely parameters of safety, strength and production (behaviour). During its life-time a lot of factors work against its life span. For instance, it may be wear caused by wrong crowning, an insufficiently working felt conditioning system, failures in the steam and condensate system as well as wrong settings in the doctors. The Andritz LCM nips those things in the bud by using diagnostic tools like on the run measurement to set the right grinding intervals or to optimize the organic coating. Frequently conducted diagnostics of the Yankee and its equipment help achieve constant running at high efficiency levels and increase the Yankee's life-time by years.

What is the ROI like, will it speed up the return on investment of a recently installed Yankee?

The great advantage is that Andritz resorts to a long-term and comprehensive knowledge in drying technology and processes. With the EMS (energy management system) customers have the right tools for energy consumption optimization, in combination with the LCM the complete access to the experts' knowledge. This allows defining the specific bottlenecks and highlights the potential of existing equipment.

In fact it doesn't matter if the Yankee is new or old - the LCM is always the right solution. One of our strengths is that we usually offer complete lines - we have the knowledge of and experience about the whole production process. We are not limited to mechanical issues or chemical processes, we have the complete "power" from process, automation, instrumentation and operational experience combined in this one tool.

Anything else the life cycle management scheme offers customers, i.e., not just the Yankee, but service around it on paper and board machines?

Apart from the Yankee itself, the life cycle management covers "everything around the Yankee", namely press rolls, hood and process air system, doctors and the chemical coating application. Measurements can be made in the press roll area (nip loads or vibrations); case studies of press concepts for specific customer requirements (end product qualities) can be conducted. In the hood section measurements and adjustments of the ventilation system (right balance) can be done, the system's economy can be defined and optimization possibilities (e.g. switch from gas to steam) can be shown. The doctors' check (working mode, necessity of blade material change)completes this area

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