摘要 |
1. Process for the injection of metered quantities of pulverulent materials by pneumatic means and at a plurality of different points into an enclosure which is under variable pressure, through pneumatic channels fed with pulverulent material and propulsion fluid under pressure supplied by a booster, characterized in that in each transport track an intermediate deposit of pulverulent material is provided in a proportioning hopper into which the pulverulent material is introduced at pressure P1 , in that the pulverulent material is extracted by means of a current of gas at a pressure P2 lower than P1 , in that the pressure difference DELTA p = P1 - P2 is continuously measured and in that the pressure P2 is set at a level which ensures that the pressure difference DELTA p will correspond to a certain quantity of pulverulent material transported per unit of time by the carrier gas at a pressure P2 . |