Mixing machine for homogenising a liquid mixture containing bitumen with solid granules

A bitumen mixing machine operable to mix a liquid mixture containing bitumen with solid granules so as to obtain a homogenised liquid bituminous mix, said machine comprising:

• a cylindrical container arranged coaxially to a vertical axis and operable to contain said liquid mixture containing bitumen and said solid granules;
• heating means operable to heat the inner surface of the side wall of said cylindrical container;
• a mixing assembly which is mounted axially rotatable within said container to rotate about said vertical axis;
• a driving unit operable to rotate said mixing assembly about said vertical axis;
• said mixing machine being characterized in that said mixing assembly comprises:
• scraper means comprising a helicoidal blade extending coaxial to said axis within said container and has its outer peripheral edge in contact with said inner surface of said container so as to scrape the material adhering on the inner surface;
• and
• crushing means, which are structured to mechanically crush said solid granules against said inner surface of said container, said crushing means comprise at least one pressure roller, which is arranged in abutment with its outer cylindrical surface on the inner surface of the container and, during rotation of said mixing assembly rotates about an axis parallel to said vertical axis so as to crush the solid granules against the inner surface of the container.