Analysis of transient ash pneumatic conveying over long distance and prediction of transport capacity

• Long distance and high capacity ash pneumatic conveying is investigated.
• Pressure transients in the transport pipeline are measured and analyzed.
• Dispersion of measured pressure amplitudes is observed.
• Analytical method is presented for the prediction of transport pipeline capacity.

Pneumatic conveying of the lignite ash from blow tanks to a nearly 600 m distant silo at the 620 MWe thermal power plant is analyzed based on pressure measurements along the telescoping transport pipeline. Transient character of the ash transport is shown with an occurrence of blockages. The ash transport capacity of the pneumatic conveying is determined by predicting a pressure drop in the steady-state compressible air–ash mixture flow for a defined air flow rate, inlet and outlet pressure values and lengths, diameters and inclinations of pipeline sections. The predicted transport capacity is in agreement with the lignite ash production calculated on the basis of lignite ash content and a lignite mills load. In addition, the calculated pressure change along the pipeline shows good agreement with mean values of measured pressure amplitudes at a number of locations along the pipeline. The presented modelling approach can be applied to the prediction of conveying capacity of ash transport pipelines.

Transport capacity of the ash pneumatic conveying is determined by predicting the pressure drop in steady-state compressible air–ash mixture flow under problem defined air flow rate and inlet and outlet pressure values. The calculated pressure change along the pipeline shows good agreement with mean values of the measured pressure amplitudes.Figure optionsDownload as PowerPoint slide