Advantage Yankee casted and steel

The heart of Tissue Machine 

More than a century after it was invented, the Yankee is still the heart of the tissue machine. Nothing has surpassed it. Of course, technical development has been extensive. Modern Yankee cylinders are safe and reliable and offer great performance along with energy efficiency. Customer needs have evolved, too, and not all tissue-making is the same.

The world’s only complete range of Yankee solutions

We believe in providing the ability to choose, and therefore we offer both steel and cast-iron Yankee cylinders. And we are the only manufacturer that can do so. We also offer the most complete range of machines and solutions for tissue, paper and board manufacturing.  

The most important benefits of Valmet Advantage Yankee dryers come down to two words: proven and choice. Matched exactly to your needs, rest assured you have top safety, availability, long service life and excellent performance along with simple design, quality materials and high-precision machining and welding. Among our installed machines and Yankee cylinders are found the world’s absolute fastest, most energy efficient and most productive. You can also count on unbeatable process knowledge and support with a worldwide service network. 

Adaptable to different needs

In addition to principal requirements from the Yankee, such as safety and drying performance, there are also specific needs for different paper making processes. Conventional processes typically mean wide operating ranges and high pressing loads in combination with demands for uniformity and low vibration levels. Emerging hybrid processes, like the Advantage NTT technology for manufacturing textured tissue, as well as the Advantage ThruAir or TAD process for structured tissue, require the Yankee dryer to function at varying condensing rates, withstand high doctor loads and have a surface susceptible to specialized process chemicals. 

 

Steel Yankee dryer

   

Cast-iron Yankee dryer

 

 

Compare the advantages: steel and cast-iron Yankee dryers  

Drying capacity, energy savings and safety are, of course, important in Yankee selection. Yet there are other critical characteristics to consider when choosing a Yankee dryer for the paper machine and process. This comparison chart provides a quick overview to help you get started with defining your needs. 

 

Comparison Chart
Feature  Steel Cast
Drying capacity (theoretical)

Stronger steel allows for thinner shell but can be compensated by deeper grooves for cast. Practical, process dependent drying limitations.

 

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Energy efficiency (theoretical)

Relates to drying capacity. Drying more with Yankee reduce losses in AirCap. Yankee itself does not use less energy.

 

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Saftey

Steel is generally a better material for pressure vessels. But design and quality are equal important. Valmet has excellent safety record.

 

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Surface proporties (when metallized)

Both cast and steel shells are metallized with the same type of thermal coatings.

 

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Surface proporties w/o coating

Cast iron provides a good papermaking surface as is. A steel shell is too soft and must be metallized for papermaking.

 

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Long-term reliability and durability

Cast iron has been used and proven for over 150 years. Ribbed steel dryers have been in operation for much shorter time.

 

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Surface temperature uniformity

High quality cast iron is uniform with even properties. A welded shell has small variation between weld and plates. Thinner shells more sensitive.

 

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Vibration damping properties

Grey cast iron has excellent vibration damping properties, 10 to 20 times that of steel.

 

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Corrosion and erosion resistance

The free graphite of cast iron forms a barrier to corrosion. Steel has no free graphite and is more exposed to fatigue and erosion.

 

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Maintenance and inspections

Well-established recommendations and methods for cast Yankee. Know-how for steel Yankee under development.

 

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Process compatibility (TAD, hybrid)

TAD and hybrid processes utilize higher doctor loads known to quickly deteriorate metallized shells. Steel unproven.

 

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High press load capability

Very little experience in the industry with steel Yankee and high press loads. Steel is stronger but cast iron has good fatigue resistance.

 

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Others (top speed, stability)

Limited experience in the industry with steel Yankees in top speed tissue machines..

 

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