Ash deposition mechanisms in Waste-to-Energy plants

抄録

Some ash particles in municipal and industrial waste adhere to heat exchanger tube surfaces, which causes problems such as heat-transfer inhibition and operational problems in Waste-to-Energy (WtE) plants. The objective of this study is to provide further understanding of ash-deposition mechanisms for various metal surfaces in WtE plants. First, the adhesion force between an ash pellet, which was sampled from a WtE plant, and an alloy specimen was measured to investigate the mechanisms that increase ash deposition. Second, the adhesion interfaces of the specimens were analyzed after the adhesion force measurement. The result was that the adhesion forces of all specimens increased with the interface temperature, and there was a clear temperature dependency on the force. The adhesion force of the ash pellet to austenite stainless steel AISI 304 was larger than to AISI 310S or to a surface-modified AISI 304 due to a lower Cr content. Moreover, analysis of the adhesion interface and the thermodynamic equilibrium calculation supported the results of the adhesion measurements.