The analyses of Janssen, Jenike, Walker and Walters for the wall pressure distribution in the bunker have been drawn attention of many investigators. However, only several experiments have been performed against these analyses, there have been few reported date measured with various experimental condition.
In this paper, the authors measured static and dynamic pressures of the bulk materials (powders of GB 733 and granular materials of GB 708) in the modle bunkers using three defferent hopper angles which retained from horizontal to 75°, 45° and 90°, and discussed.
As the results, the following conclusions are obtained:
(1) Dynamic pressures in the bunker are roughly dependent of the change of discharge velocity but slightly increase in the hopper part closed cylindrical part (within the limited about 300cm
3/s).
(2) In mass flow conditions using hopper angle of 75°, dynamic pressures of the cylindrical part closed to the hopper part do not saturate a constant value for sufficient depth as the analysis of Walters, and become higher.
(3) In case of mass flow conditions with powders, dynamic pressures increase slightly than static pressures, but do not greatly increase as dynamic pressures of granular materials.
(4) In case of funnel flow, the peak of dynamic pressures occurs to two parts of the wall in the bunker, that is in the part changed from mass flow to funnel flow and in the part closed to the discharge opening.
(5) In case of set an obstruction on the wall in the bunker, the dynamic pressures become higher in the part closed to the obstruction, consequently it is found that the obstruction corresponds to the top of the dead space in funnel flow.
(6) Dynamic bottom pressures in a flat-bottom bunker become higher in the part closed to side of wall where correspond to the top of the dead space.
抄録全体を表示