Paper Mill processes use raw materials or recycled paper products to produce paper towels, news print or personal tissue items, which require the water quality used to be the major criteria in consistent and reliable manufacturing.
When your paper machine pulp materials are in operation, even a small deviation in water quality to the polymer injection can reduce your output and on line production time. Pulp and paper industries consume on average 17,000 gallons of water per ton of paper produced. Using Ion Exchange processes Puretec Industrial Water can provide a consistent water quantity and quality for the Paper manufacturing process.
Why water is the most critical part of the Pulp and Paper Manufacturing Process:
- Steam Generation Makeup Softening
- Condensate Makeup
- Gas Turbine Water Treatment Solutions
- Process Water Conditioning Equipment
Ion exchange has proven to reduce the water consumption of many of the process within the Pulp Mill.
Several mills have successfully demonstrated water reuse in its bleaching stages by establishing counter-current flows when they have incorporated non-chloride bleaching stages. Since the bleach plant is the single largest consumer of water within pulp mills, focusing on the recycling and efficacy of water within the bleaching sequence can significantly reduce water use within the mill. One such example is a pulp and paper mill in Canton, North Carolina, that has reduced water use by over 40% since 1990 through an ion-exchange system within its bleaching system.
Water Use Water is used in all major process stages, including raw materials preparation (e.g., pulping and bleaching) and paper machines (e.g., pulp slurry dilution and fabric showers). Water is also used for cooling, material transport, equipment cleaning, general facilities operations, and to generate steam for use in both thermal and mechanical processes as well as on-site electricity generation. Overall water intake has been reduced annually through various conservation efforts. Our 2013 water usage was 9.9% less than 2009. Relative Cost of Water The various water systems within the mill have vastly different costs based on electricity consumed for pumping, energy used for heating and any treatment processes required for either incoming or outgoing streams. A hose left running could cost over US$30/day and steam leaks can be very costly if not repaired quickly.
Water Reuse Water is reused in various forms throughout the mill and requires different levels of treatment depending on its use. For example, water used in the steam systems (boiler feedwater) must be purified to minimize corrosion. Once steam is condensed it is recaptured and reused in the steam system. By contrast, raw water can be used without any treatment for non-contact cooling systems and can be returned directly to the river as long as it is not too warm.