Circular giants meet booming industrial demands for stacking and reclaiming
25 Mar 2022
Amid a year-on-year growing market upturn for containerboard and renewable energy, managing the huge volumes of organic material required for these booming industries requires an expert touch, not only to ensure the quality of the material, but also the safety of the pile and its efficient management.
All these elements are tied up in each other, and automation is proving to be the solution. This is a Bruks Siwertell speciality. With an install base that totals into the hundreds, a very popular choice is the fully automated Bruks circular blending bed stacker reclaimer (CBBSR). Almost hypnotic to watch in action, they are in increasingly high demand. A recent order from an undisclosed packaging solutions giant, comprising a new CBBSR and truck dumper with receiving system, further swells our reference list.
Woodyards supplied by Bruks Siwertell are seen as the industry model for high-volume wood processing, expertly managing vast, neat swathes of wood chips and various other materials.
Essentially, the Bruks CBBSR lays down successive layers of material in a continuous 360-degree rotational pattern using a stacking conveyor that pivots through a complete circle. At ground level, a reclaim bridge moves into the pile with a harrow simultaneously agitating and fluidizing the material on its reclaiming face. A large diameter screw catches all the falling material and transfers it to the center where it drops onto the reclaim belt. This passes under the pile and emerges beyond its edge, leaving the base undisturbed.
They are a lifeline in the pulp and paper and bioenergy industries, which benefit fully from their true first-in first-out (FIFO) mechanism, with the oldest material in the pile always being reclaimed first and blending reducing any variation to a minimum.
This is particularly key because of their organic feedstock; a residual side-stream from wood processing, namely, wood chips and sawdust, making it essential to protect them from degradation and the risk of ‘hot spots’ from microbial action.
Automation has brought considerable benefits to woodyards. Fully automated stacker reclaimers minimize the number of personnel-hours required for daily operations, delivering significant cost savings. They have a unique design that improves inventory control, as well as maintaining consistent quality.
Automated systems also have a fraction of the carbon footprint of a manually managed pile and offer much improved emissions control. These environmental gains stem from eliminating the continuous use of diesel-powered machines used to manage the piles. Fugitive dust emissions are also reduced in comparison to them, as the gentle nature of CBBSRs mean that they do not ‘stir up’ fines and dust.
One of the largest manufacturers of containerboard and corrugated packaging in the United States, Packaging Corporation of America (PCA) – operating a network of six containerboard mills – has repeatedly turned to Bruks Siwertell for its wood-processing and handling expertise.
In 2019, Bruks Siwertell’s air-cushioned conveyor technology, The Belt ConveyorTM, made its debut at PCA’s highest-volume mill, Counce, in Tennessee, and in 2020, the company also required something special for its Wallula mill, in Washington.
The Wallula mill has two containerboard machines producing semi-chemical corrugating medium and kraft linerboard. To improve operating efficiencies and reduce environmental impact and material degradation, PCA approached Bruks Siwertell looking to automate its woodyard.
Bruks Siwertell’s comprehensive solution includes two Bruks back-on truck dumpers, with covered receiving hoppers, which can each process up to six bulk trucks an hour; two circular blending bed stacker reclaimers (CBBSRs), one for handling wood chips, with a storage capacity of 35,000 tons and the other for sawdust, with a storage capacity of 20,000 tons; a sawdust metering tower; and a complete conveyor system featuring Bruks air-cushion conveying technology, The Belt Conveyor.
The entire package of equipment is designed to reduce dust emissions and control them. This is particularly important as the mill is located in an extremely arid environment, with an average rainfall of less than 20cm a year. For example, the truck receiving systems are covered and equipped with dust collection systems, the conveyors are fully enclosed, and the overall system is design to operate at speeds that mitigate dust creation.
Phase one of this installation, which includes the two fully enclosed truck dumpers, the conveying system featuring The Belt Conveyor, and one CBBSR, is now commissioned and in operation. Closely following is phase two, which will include the installation of additional The Belt Conveyors and the second Bruks CBBSR. This will be completed towards the end of 2022.
Committed to good service
Like all our machines, the CBBSR is designed for maximum wear life. The harrow and carriage are mounted on a robust rail system located on top of the bridge, allowing the unit to reliably travel alongside the pile. The bridge is fitted with a dedicated control room that houses critical electrical engineering components.
All stacker reclaimers are fitted with similar insulated motor control units that have an isolated cabinet complete with industrial environmental controls. Control rooms are shipped to customers’ sites pre-tested and fully assembled.
In line with our commitment to service from order to through life care, our teams are on hand when they are needed. Bruks Siwertell Americas offers customers strategic stocking programs, which ensure that any necessary spare parts are rapidly available; an agreed quantity can be pre-ordered, consolidated, tagged, packed and shipped at any time.
All our customers are assigned a key account manager following commissioning and our service team have already spent time with PCA at the Wallula mill to ensure ongoing support and the necessary spare parts are to hand.
Packaging is not the only industry where demand is increasing. The energy sector has been increasingly offsetting the use of coal in power plants by substituting it with biomass pellets. To get the highest possible energy content for the end user, every stage of the biomass production process needs to be handled with care.
At the US Greenwood Colombo Energy plant, in South Carolina, which is owned and operated by the world’s largest producer of industrial wood pellets, Enviva, several Bruks systems are in operation. The site has undergone a number of modernizations since opening in 2016, including the adoption of a fully automated woodyard from Bruks Siwertell, which now realizes its owners’ ambitious plans for growing sustainable bioenergy production.
The plant either takes delivery of pre-processed wood chips via its two Bruks back-on truck dumpers, or takes delivery of full logs which are then processed in a Bruks drum chipper to turn them into chips. All wood chips are stacked and stored using a Bruks CBBSR. The entire wood-processing and handling operation delivers a very efficient system that benefits from all the advantages of automation, ensuring the plant’s highest yields.
Enviva Biomass also operates a Bruks CBBSR at its Green Circle Bio Energy Inc plant in Cottondale, Florida. It began operations in 2008 and, with the help of its fully automated woodyard, has gone from an annual green wood chip processing capacity of 500,000 metric tons to three million.
Mills, pellet plants and power-generation facilities all operate on tightly controlled schedules with very little downtime. Our woodyards, and all their constitute components, such as fully automated CBBSRs are heavily relied upon to deliver their contents day-in, day-out with the same levels of efficiency, reliability and material consistency; and they do. They also deliver environmentally, adding sustainability to industry processes.