| 摘要 |
PROBLEM TO BE SOLVED: To attenuate large crushing sound at a time of the vol. reducing treatment of a waste plastic material by sending hot air into a treatment container through a hot air circulating passage and circulating the hot air flowing out of a heat insulating container by a blower and arranging a noise attenuating device around the treatment container. SOLUTION: A heat insulating soundproof layer 17 is the heat insulating sound absorbing material layer arranged to the entire inner surface of a heat insulating container 16 and formed from glass wool or the like. Since the heat insulating sound absorbing material has heat resistance, low heat conductivity, a fibrous structure and sound absorbing action, internal heat can be confined in the heat insulating container 16 only by laminating the heat insulating sound absorbing material to the container and the crushing sound of a waste plastic material generated within the container, especially, a sound of a relatively wide frequency range such as a medium- and high-pitched sound can be absorbed by the layer of the heat insulating sound absorbing material. Since not only a compression sound source but also the mechanical noise source of a blower 7 or an air pump 21 are present in this apparatus for reducing the vol. of a waste plastic material, a noise attenuation device is further provided to the inner peripheral surface of the main body covering all of devices such as the blower 7 and the like. |
