Dryer change-out

Affiliated company Irving Tissue, a tissue production firm, had a requirement to remove a 55USt dryer and replace in kind. Both systems have a diameter of 12ft 5in and 13ft 4in-long cylinders with 4ft-long shafts sticking out of either end. Irving was responsible for all movements of the outgoing and incoming units.

Ryan Long, operations manager for southern New Brunswick and Nova Scotia at Irving Equipment, explained that the scope of work presented four standout challenges: travel route, second floor location of the dryer, floor strength, and tight confines for blocking up the loads.

In addition to the LP350, Irving employed an Enerpac EVO power pack system and four 50USt capacity jacks for vertical jacking of the dryer; a pair of 8USt capacity Broderson carry decks for material handling; and a 250USt capacity Liebherr LTM 1200 all-terrain crane, used to hoist the Yankee off the second-floor temporary mezzanine that the dryer was slid out onto.

Since the dryer was a primary component of an existing in-line paper machine, it was deeply embedded within the plant and required the project team to make three directional changes and three elevation changes to avoid existing infrastructure.

Long said: “As the dryer was on the second floor of the plant, in order to get it to ground level a temporary mezzanine was designed and installed outside of the plant at the same elevation as the sliding system, and the back wall of the plant was removed. This allowed us to slide the dryer completely outside of the building and onto the mezzanine before lifting it off with our Liebherr LTM 1200.”

It was determined that the concrete floor of the building could not support the loads that would be imposed by the dryer as it travelled along its path. In order to mitigate this, a steel grillage system was engineered and installed to bridge the floor between supporting columns under the floor for the entire route. Since the dryer removal was part of a larger overall shutdown, the grillage system had to be installed in a sequence that didn’t impede that scope of work.

The underside of the installed dryer was approximately 5ft off of the floor, which made for a considerable amount of blocking to be done when lowering it down to the floor. “Combined with the awkward 5ft of space, we knew it would be time-consuming and hard on the rigging crew to do all of that work while hunched over,” Long said.

The LP350 eliminated the need to remove a roof section and lift out the dryer with a 500USt capacity class crawler crane, which would have added significant mobilization and crane pad costs. The Hydra-Slide system was compact and easy to use within the tight confines of the plant. The method also facilitated the three required directional changes in 31ft, 38ft and 135ft increments, with the aforementioned elevation changes along the way.

The slides took place across two 12-hour shifts. Outside, the LTM 1200, part of Irving’s fleet of 100-plus cranes, lifted the dryers with a Modulift spreader beam beneath the hook and slings basketed around the dryer shafts. The paper machine was shut down whilst the dryer was being replaced.