Development of the design of multipurpose equipment for crushing plastics and obtaining powders

A substantially new in design an experimental sample of complex equipment intended for crushing of various fragile and elastic materials, in particular plastics and obtaining powders of a different dispersion was built. The equipment consists of a shock-rotary crusher, a six-polar electromagnetic separator, two types of classifiers that allows to obtain the powders with a dispersity up to 0,05 mm applying raw materials of 5÷15 mm of diameter.

The rotary crusher, that is used in the first stage of crushing, is a modification of well-known design of the Bauman crusher and is refined using the declarative patent of Ukraine 60388 “Method of nanopowder’s classification”. In accordance with Bauman method the calculations of parameters of the nodes of the rotary crusher were made and υcr = 50 m/s value of destruction rate of the material was obtained Based on the calculations for our crusher’s design AC power three-phase motor of 3,5 kW capacity with rotation velocity n = 3,000 r/min have been selected.

At the second stage a rotary electromagnetic separator is installed. The last one provides powders separation by the fractions. Classification occurs under the action of centrifugal force on crevice-sifting surface formed by two bodies of rotation mounted in such way that between the adjacent horizontal surfaces a regulatory gap is formed through a micro-screw that provides the required powder dispersity. The peculiarity of such classifier is that the rotor is made in the form of a disk and a cone. The disk is rigidly fixed on the hub of the engine shaft, and the cone with a hub is fixed movably on the engine shaft. In the hub there are windows for filling the powder. The regulation of powder dispersity is carried out via micro-screws which are connected through the pressure washer with the hub of the cone, and spring mechanism is installed between it and the disk. The combination of separator work and two types of classifiers allows to obtain a small fraction of powder of the crushed material by the size of 0,05÷0,1 mm.

The developed complex equipment is multifunctional and can be applied during the manufacturing of components of composite materials, powders of different nature and dispersity, as well as recycling of plastics.