| 摘要 |
<p>A method of gravity mixing of powdery to granular material stored in a comparatively slender vessel or silo, consists of discharging the material from the bottom of the silo and recycling it to the top in a specific sequence. In a first stage, the entire quantity to be recycled is discharged from the tapering bottom of the silo via a central pipe and is recycled to the top. During succeeding stages, the entire quantity to be cycled is drawn from the bottom of the silo via a number of discharge pipes and also simultaneously from the central pipe. All the pipes are of equal cross-section. Pref., in the second and all subsequent stages the material is drawn partic. from the tapering hopper bottom of the silo. Esp. for mixing stored plastics powder or granules. It is found that when the silo bottom is first opened and discharge is permitted through the central pipe, this produces a 'chimney' effect in the silo which effectively draws off material from all levels up to the top. In this way different sizes at different levels become thoroughly mixed during the first stage.</p> |
