Magnum-sized recovery boilers – enabling the creation of giant pulp mills

Ageu Silva, LATAM Divisional Director, Pulp & Power, ANDRITZ, says, “Up until relatively recently the size of the recovery boiler limited the capacity of the fiberline at pulp mills. The reason for this limitation was due to availability, as when recovery boilers go down, all production at the pulp mills stops.

ADAPTING TECHNOLOGY FOR SAFETY AND EFFICIENCY    

While increasing capacity, there are several examples of how ANDRITZ has improved the technology required for larger boilers over the years. One such example is the introduction of an increased tube size diameter for furnace walls to improve circulation and avoid leakages. The larger diameter of the tubes creates less pressure drop and allows the water to circulate better, cooling down the tubes more effectively. 

Silva adds, “Due to the greater size of the boiler furnaces ANDRITZ considers larger diameter tubes as the only safe solution to avoid leakages and possible explosions.” 

Another example is the location of the sootblowers in the boiler bank which ensures the boiler is kept clean for maximum uptime. Lindh explains, “For larger recovery boilers a boiler bank with two sootblower cavities is supplied to ensure the range covers all areas. ANDRITZ has also created a solution that contains a wider boiler bank spacing in order to prevent fouling or plugging in this critical area.”

Furthermore, ANDRITZ has introduced added automation and robotics to enhance safety and improve efficiency of the larger boilers. Silva says, “We have successfully installed various digital technologies and robotics, including Smart Smelt Spout Robots which improve the safety of the furnace area of the recovery boiler and our vision systems that convert process images into digital data for improved operational performance, and less manual intervention.”   

MAXIMIZING RAMP UP SPEED AND QUALITY OF ONGOING SERVICE 

With the experience of having seven of the largest recovery boilers in operation or under construction around the world, ANDRITZ prides itself in fast start-up and ramp up speeds, “The speedy ramp up to full design capacity is a very important issue for our customers,” says Silva. “Our experience in the installation, start-up and ramp up of recovery boilers and complete mills is second to none, and our installations are ramping up faster and faster, often reaching nominal capacity in record times. 

When it comes to service, ANDRITZ has located its service centers with skilled engineers and spare parts close to customers’ mills to ensure maximum lifetime service levels.  The latest developments include an upcoming modern service center located at Três Lagoas in Mato Grosso do Sul state, Brazil, in addition to the outstanding existing service center at Araucaria in Paraná state. Another development is a brand-new service center at Palembang on the island of Sumatra in Indonesia, which will be fully operational at the end of the year. The center will allow ANDRITZ to service the larger mills on the island as well as provide services to other mills in South-East Asia. 

Silva concludes, “Our customers are delighted with our exponentially growing service offerings, particularly at the heart of large, new pulp mill expansion areas. We now have the ability to manufacture spare parts for large recovery boilers, as well as for parts across the rest of the mill, ensuring maximum uptime and quality maintenance and service.”