Waste paper pulp production process
Installation of the secondary separation pulper for maceration of collected waste paper.
Pulper is a facility to facilitate maceration of collected wastepaper to form a slurry and to remove large foreign materials. The pulper swells fibers to promote maceration and adds a small amount of caustic soda to help remove inks when the treated paper requires deinking.
Current Operation: Wastepaper was soaked in water at a low rate of only several percent and addition of vigorous agitation of a rapid revolving impeller to achieve maceration by slashing.
Drawback: Foreign materials are crushed as well which leads to removal of it in the subsequent processes and the rotation and agitation consumes a large amount of energy. This means that the former process was at very low energy efficiency.
Modification: Secondary pulper is established. The secondary pulper conducts preliminary maceration and continuously remove foreign materials without breaking them. In addition, it reduces the degree of maceration and hence achieve energy saving in the total operation of wastepaper processing.
Heat Recovery by Sludge Incinerator
This technology consists in improving energy conservation efficiency by recovering exhaust heat from the fluidized –bed incinerator for burning sludge discharged from the papermaking process of paper mills.
Current Operation: Sludge and solid waters are disposed by landfilling.
Drawback: Final disposal facilities for sludge and solid wastes are becoming hard to secure and contains combustible substances at high concentration. Under such a circumstance, recovery of exhaust heat from incineration is desired.
1. Sludge and...