| 摘要 |
<p>An apparatus and method for pumping powdered materials. The apparatus includes a hopper having a discharge outlet in one end wall thereof. An agitator gently stirs the powdered material to prevent it from bridging and packing in the hopper. A sliding cylindrical sleeve, axially aligned with the discharge outlet, and a main piston therein are movable in the hopper for successively entrapping, or segregating, and discharging a portion of the powdered material through the discharge outlet. An auxiliary hydraulic cylinder within the sleeve contains a plunger that slides through a bore in the main piston. The plunger is independently movable relative to the main piston and sleeve, and, upon retraction, provides a void in the entrapped material to prevent bridging and packing in the sleeve. A fluidizing element in the hopper below the path of travel of the sleeve keeps the powdered material in a loose condition to further eliminate any tendency to bridge or pack in the sleeve. A slide valve is mounted on said one end wall of the hopper for controlling the discharge of powdered material from the discharge outlet into a chamber that may be pressurized. The method comprises essentially, extending the plunger into the body of powdered material, entrapping a portion of the powdered material adjacent to and surrounding the plunger, withdrawing the plunger from the entrapped powdered material to form a void therein, and discharging the entrapped material.</p> |
