Investigation of Slurry Erosion in Pipeline Materials

Abstract

Erosion wear is very serious problem in slurry pipelines specifically in thermal power plants. Wear of the pipelines results in loss of capital money due to failure and frequent replacement of pipelines. According to FAU-2012, 88 thermal power plants in India with installed capacity of 80458MW, consume 407.61 million tonne of coal (lignite based) every year. Huge amount of bottom ash is produced every year in these thermal power plants and this is transported to ash ponds mainly through mild steel piping system. Literature survey of various researchers shows the high erosion wear of mild steel pipeline material with bottom ash slurry. In the view of above, author is motivated to study erosion wear behavior of different general purpose materials and coatings. Erosion wear of WC-12Co and Ni-20Cr2O3 coated and uncoated Mild steel, SS 304 and SS 202 materials is evaluated by using slurry pot tester with bottom ash slurry. High velocity oxy-fuel process is used for the coating. Erosion wear at four different speeds 500rpm, 800rpm, 1100rpm and 1400rpm is evaluated at 25% and 45% slurry concentrations with 90min and 180min experimental study. Erosion wear increases with increase in slurry concentration and speed, it is noticed that at low speeds (500rpm to 800rpm) rate of erosion wear is more as compared to higher speeds(1100rpm to 1400rpm). The speed exponent and concentration exponent are also calculated and are in good agreement with previous research works, experimental results are also investigated with taguchi approach so as to evaluate the influence of speed, concentration and time parameters on the erosion wear of the materials and it is found that influence (percentage) of speed is more on erosion wear and is followed by time and concentration parameters.