3. Results and discussion
3.1 Morphologies of PPS-based bag
filter materials
SEM images of PPS-based bag filter materials collecting from coal-fired
power plants with different loading units were shown in Fig. 1. A
three-dimensional interpenetrated configuration is easily observed for
all samples regardless of loading units of coal-fired power plants,
which is built by stacking of PPS fibers through nonwoven technology to
furnish the bag filter with open-cells pores and high porosity. The
existence of above network makes it possible to filter dust particles
effectively for PPS-based bag filters with excellent dust rejection
rate.
When the loading units is below 200 MW (sample 1#-5#), the relatively
smooth surface along the fiber axis accompanying with little particles
is observed for sample 1# and 2#. While the regular cracks liking
knife cuts that vertical to the fiber axis appear for sample 3#, 4#
and 5#. From Table 1, the status of bag filters changes from using to
complete failure for sample 1#-5#, indicating that the evolution of
surface of PPS-based bag filter materials from smooth to cracked occurs
as failure degree increases, which is in line with the content variation
of SO2 in the system and would be discussed in detailed
in section 3.4. The depth of cracks becomes more intensified for
completely