Evaluation of the effectiveness of the bulk thermal stresses for kraft recovery boiler fireside deposit cleaning.APPLICATION: This work can help mills determine how to achieve the maximum thermal shock Thermal shock in mechanical models Thermal shock is the name given to cracking as a result of rapid temperature change. Glass and ceramic objects are particularly vulnerable to this form of failure, due to their low toughness, low thermal conductivity, and high effect, leading to a soot-blowing process that is most beneficial for cleaning fireside deposits. Removal of fireside deposits from the heat transfer tubes in kraft recovery boilers Recovery boiler is the part of Kraft process of pulping where chemicals for white liquor are recovered and reformed from black liquor. In the process lignin of the wood, bound in black liquor at this phase, is burned and heat generated. is carried out by sootblowing and occasionally "chill-and-blow" practices. During chill-and-blow, black liquor Black liquor is a byproduct of the Kraft process, (also known as Kraft pulping or sulfate process) during the production of paper pulp. Wood is decomposed into cellulose fibers (from which paper is made), hemicellulose and lignin fragments. flow is reduced to rapidly cool the deposits. Thermal stresses generated in the deposit as a result of thermal shock can effectively weaken the deposit, facilitating its cleaning. This work involves the investigation and quantification of the mechanical weakening effect of thermal stresses generated by the transient temperature gradients temperature gradient n. The rate of change of temperature with displacement in a given direction from a given reference point. temperature gradient . |
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