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ANDRITZ MC technology – for smoother running fiberlines

ANDRITZ technologies enable operations at medium consistency (MC) conditions throughout the fiberline – saving water, energy, and equipment

The challenge

Reducing unnecessary dilution phases, saving energy, and reducing the overall equipment space require the maintenance of a constant consistency throughout the system.

The solution

ANDRITZ MC equipment can be utilized throughout the fiberline in key positions to ensure that medium consistency conditions can be maintained throughout the entire process.

Processes and technologies available from ANDRITZ

AMix chemical mixers

The mixing of chemicals in the pulp slurry is key to environmentally sound bleaching. Proper mixing provides homogeneous bleaching conditions, reduces consumption of chemicals and energy, improves product quality, and reduces environmental load.

The ANDRITZ AMix AC chemical mixer is designed for mixing both gaseous and liquid chemicals in medium consistency conditions, while the AMix AZ ozone mixer is designed specifically for ozone bleaching.

AFlow reactor feeders and dischargers

When medium consistency pulp is pumped, a plug flow of pulp is generated in the pipeline. To maintain this flow and avoid channeling in large diameter reactors, the pulp feed must be uniformly divided across the entire diameter of the reactor. When the pulp is discharged from a pressurized reactor (typically required in oxygen delignification and in some bleaching processes) there is potential for plugging and channeling, if the discharge is not performed correctly.

To avoid plugging and channeling, ANDRITZ developed the AFlow ARF reactor feeder and the AFlow ARD reactor discharger. AFlow feeders and dischargers fluidize the pulp to create flow characteristics similar to water. This makes feeding and discharging smooth and clog-free. The ARD reactor discharger is equipped with gas removal capability, which has proven to be beneficial in oxygen-based bleaching processes.

ADS bottom scraper and ATS top scrapers

Scrapers are required in medium- or high-consistency stock towers and in atmospheric reactors in the bleach plant. At the bottom of a stock tower the discharge scraper ADS prevents channeling and ensures even discharge by scraping the stock over the entire bottom area and directing it to the suction opening of the discharge pump.

In bleaching, the ATS-LC and ATS-MC tower top scrapers are designed to ensure a stable, disturbance-free discharge of an atmospheric pressure tower for either low-consistency or medium-consistency discharging. The discharge scraper produces a continuous and stable discharge flow from the bleaching tower, making it possible to feed the washer without the need of intermediate tanks, pumps, or transfer screws.

MC equipment product family

ANDRITZ MC equipment product family

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