Steel cylinders for the dryer section

EvoDry a winner at WEIG-Karton

2015-07-06 - Compared with cast iron cylinders, steel cylinders offer impressive features like higher thermal conductivity and greater material strength. These and other benefits mean that it makes good sense to install steel cylinders when upgrading dryer sections. Recently, WEIG-Karton also opted to install EvoDry steel cylinders at its plant in Mayen, Germany.

Because EvoDry steel cylinders for the dryer section have high material strength they can have a thinner wall thickness than comparable cast iron cylinders. The temperature distribution in EvoDry drying cylinders is very even, which ensures optimum paper quality. The head and shell of EvoDry cylinders are welded to one another, so that larger sheet widths can be passed over the drying cylinder. The high material strength and low wall thickness of the steel cylinder result in higher thermal conductivity, improving heat transfer by 7 – 10 %. Thanks to this high efficiency, production can be stepped up or investment cost minimized when using EvoDry, as fewer drying cylinders need to be installed.
On two machines in Mayen, WEIG-Karton produces recycling board for the folding boxboard industry and plasterboard for the plasterboard industry. Total annual production is 630,000 metric tons of board. In 2014 the company decided to rebuild the dryer section of its BM 6 plasterboard machine. Voith won the order to convert the dryer section and installed a total of 31 EvoDry steel cylinders. The board manufacturer opted in favor of steel cylinders to achieve the maximum possible drying efficiency. As well as supplying the cylinders, Voith was also responsible for assembly and commissioning.

The rebuild of the dryer section was a smooth and fast process. After just 19 days, WEIG-Karton could resume production of plasterboard on its BM 6. “We are absolutely delighted that the rebuild was accomplished so quickly and smoothly,” says Henning Dippel, Operations Manager BM 6, adding: “We are equally pleased about our decision to install the EvoDry steel cylinders. We have been able to save space and yet achieve better runability and energy efficiency than before.” Shortly after startup of the EvoDry steel cylinders the guaranteed CD moisture profile values have already been achieved.

EvoDry drying cylinders can be used for the production of all paper grades. Optimum results are achieved with paper grades that are dried at high temperature, for example board and packaging papers.