powders of specific particle size, high productivity and versatile applications. By definition, âSpray drying is the transformation of feed from a fluid state into a dried. particulate form by spraying the feed into a hot drying medium.â (Masters, 1991) A spray dryer operates on convection mode.
Sometimes the grounds and maintenance department of a town or county creates mulch from trees that have been cut down and they make it available to the public. To lay a 4-inch-deep spread of bark mulch in a 300-square-foot area, a landscape or garden service will charge $425, which includes the material and labor. You can buy the mulch for $85 and do it yourself, and pocket a 80 percent saving.
1 Most bark mulch and wood chips fall cost $20-$30 per cubic yard. 2  Gravel and stone start at about $25 per cubic yard but can range up to $80, depending on quality, color and availability.