Importance Of Paper Machine Building Hall Ventilation: A Rigorous Approach For Evaluation And Problem Solving - Case Studies

摘要

Importance of paper machine building hall ventilation is often given lower priority by mills as common benefits, such as improved personnel working environment and reduced building maintenances do not translate into an immediate financial return. However, severe negative consequences such as condensation and water drip back on finished paper, fog, uncontrolled air flow, building corrosion and structural failure are encountered in long term for a poorly designed building ventilation system. Quite often ad hoc approach is used to assess, design and quantifying performance of a building hall. In designing paper machine building ventilation, a rigorous approach based on system heat load and minimum process exhaust required at maximum production rate in line with Tappi guidelines (TIP 0404-50) is the best approach. Such methodology has been used for case studies of two paper machines producing medium and test liner papers. Analyses of audit data of temperature, humidity, air flow profiles and direction of air movement inside the building hall suggest that the poor ventilation of the building halls housing these two paper machines are very poor. This is supported by the calculated heat load, required and existing process exhausts. The direct consequence of poor ventilation was fog, condensation of water vapour, corrosion and unpleasant working conditions inside the building hall of these two paper machines. The mills are currently in the process of implementation of recommendations arising from this investigation.