Electric Power Control

Author:  Keller, A. M.
Source:  US Patent 2,505,049
Doc ID:  1950000
Year of Publication:  1950
Abstract:  
This invention relates to the art of feeding powder, and more particularly to electrical means for controlling the flow of powder. In feeding powder, especially iron powder, which is carried and propelled by a fluid, such as air flowing under substantially constant pressure through a conduit, the scouring and rapid erosion of mechanical valves present a serious problem. Such valves must be properly designed to prevent clogging, and they need to be replaced frequently. This is not only expensive, but requires entire systems to be shut down while the valves are being repaired or replaced. The main objects of the invention are to provide an improved method and means for feeding powder, particularly powder containing or comosed of particles responsive to an electric field: and to provide novel feed means for measuring powder in a feeding system. According to the invention the feeding of ferrous powder, for example, is controlled by a magnetic field crossing the path of such powder. In one form of the invention a novel magnetic powder feed system is provided which includes a nonmagnetic tube for conducting powder therethrough and and electromagnet for polarizing powder in such tube to control the powder fed through the tube. The powder may be paramagnetic or diamagnetic as well as ferromagnetic, such as powdered iron, nickel, or magnetic alloy. In any case the novel control is quite simple and avoids disadvantages of the prior art.