A modular piping system allows the connection of individual pieces of equipment in any configuration to simulate a wide variety of industrial systems.
Equipment available for contract research in fiber recycling is listed below.
Western has two identical Beloit Jones 12 inch double disk refiners. One is located in the recycling plant and the other is located at the wet end of the paper machine. Both refiners can be used during a recycle trial.
In flotation deinking the goal is to remove ink and other hydrophobic contaminants from recycled paper furnish. This unit is very good at removing the small toner particles from laser-printed mixed office waste. The flotation cell is operated at about one percent consistency using a surfactant to help create bubbles. Air is pumped into the center of the cell creating bubbles. Ink particles attach to the bubbles and together float to the surface of the cell. The cell contains paddles that remove the resulting foam. Surfactant levels are nominally in the range of 0.3 to 1.0 percent.
Washing is another common step used in deinking recycled paper. The process of washing involves two steps: dilution of the stock followed by thickening. In Western's pilot plant the diluted stock is thickened by first passing it over a sidehill screen and then a belt press. The stock feeding the sidehill is typically one percent and thickens to five percent. The belt press thickens the five percent stock further to twenty-five to thirty-five percent consistency depending upon the furnish used.
A kneader is a high consistency mixer that provides an intimate fiber-to-fiber rubbing action. This kneading breaks up contaminates (ink) off the fibers. It is also an injection point for bleaching liqours. The action also reduces the size of the ink particles so they are easier to remove later during the recycling processes. Other contaminants are also reduced in size. The Shinhama kneader at Western is fed stock from the belt press.
A dissolved air clarifier (DAF cell) is used to reclaim and clarify mill process water. As mills recycle water to reduce freshwater use, suspended and dissolved solids build up in the water systems. A DAF cell injects air under pressure into the recycled water and the air actually “dissolves” into the water. Next, the water is released into the cell at atmospheric pressure and the air comes out of the solution forming very small bubbles that carry suspended solids to the surface. The clarifier skims off the foam. In a mill, the foam is sent to a press and the thickened solids are sent to a landfill. By controlling surfactant and flocculent chemistry, suspended solids levels as low as a few parts per million can be easily achieved.
The Hollander beater is used to slurry lap pulp which is refined using the double-disk refiner located at the wet end of the paper machine. It makes 180 to 200 pound (80-90 kg) batches at 4% consistency.
The Hydrasieve® is a very coarse screening device normally used to screen out large contaminates, such as wood chips, candy wrappers, and cigarette buts, from reclaimed white water. This type of screen is also known as a “scalping screen”.
Hydarasieve is a registered trademark of Andritz AG
