The semi-dense phase pneumatic conveying mode foresees that the air speed is lower than 20m/s while the auto level, or depression, rises up to 800 mbar, much higher than in the diluted phase mode. With these values, the powders are partially transported as in the fluid phase transport, the lighter particles “fly” along the pipe, while the heavier particles are transported in “blocks”, obtaining a more delicate treatment of the product. This mode reduces the energy consumption of the whole system and the crushing and de-mixing of the powders.