This article explores the hydraulic design and control of
several machines used in the waste & recycling industry. To most
of us, recycling means lugging a bin of cans, bottles, plastics,
paper, or cardboard — or any combination of these — to the curb
for pickup by our community's recycling personnel or to a
recycling center. Residential materials, however, are just the
tip of the recycling iceberg. Industry generates huge amounts of
byproducts that once were discarded but now are recycled — in
essence, turning trash into cash. In the construction industry,
for example, clearing land to make way for a building can
produce a mountain of surplus soil that can be transported to an
area where it is needed. Brush and branches can be run through a
chipper-shredder to produce mulch for subsequent landscaping,
but tree stumps call for a different process. Here, stump
grinders have emerged as a specialized tool to quickly transform
tree stumps into shredded mulch for landscaping. As you might
expect, stump grinders re