A major concern during the shredder evaluation
procedure was the potential deterioration of performance,
as measured by particle size distribution.
This might occur when hammers wear excessively
and thus allow progressively larger particles to
leave as product.
Fig. 6 is a plot of the percent fmer than several
sizes as measured over the entire trial period. The
refuse processed (tons) is the value at the end of
the working day.
There seems to be no deterioration of particle
204
size reduction during the trial period. In fact, the
shredder performed well enough tohave been able
to meet a guarantee of 70 percent less than 2 in.
(50.8 mm) in size if that was required.
One major drawback in the analysis of particle
size distributions is that no single parameter can
be used to describe a distribution. A solution to
this problem is to plot the data in such a way as
to obtain a straight line, which then allows for a
complete description using only the slope and one
point. The Rosin-Ramrnler equation [7] is such an
empirical model, and is stated as