| 摘要 |
Vacuum apparatus and methods for unloading bulk fluent material from a receptacle. An unloading tool coupled to a vacuum conveying system is moved through the fluent material at a rate automatically controlled in accordance with the vacuum pressure within the conveying system so as to afford continuous maximum efficiency of intake and conveying of the fluent material. In one embodiment, the unloading tool is supported to pivot in a vertical plane, and automatic controls are provided to coordinate the vertical and horizontal movements of the tool so that the tool nozzle moves along a straight-line path through the material, thereby allowing the nozzle to be maintained at the proper depth for optimum delivery of the material and facilitating the unloading of layers of material of uniform thickness. Structure associated with the unloading tool agitates and redistributes the fluent material in the vicinity of the tool to surround the tool nozzle with a continuous supply of free-flowing material. A safety device breaks the vacuum in the conveying system at a predetermined pressure level, thus avoiding stalling of, or damage to, the system from too high vacuums. |
