| 摘要 |
A method and apparatus for pipe pig that is employed in a piping system for the purpose of recovering product. The pipe pig, or simply "pig," is utilized to flush or purge a piping system, which includes a pipe that is normally filled with a product stream. The pig is a substantially solid slug that is introduced into the flow within the pipe. The pipe pig includes at least a component of a product stream and the pig is at least partially frozen to achieve its substantially solid form. The pipe pig is inserted or alternatively formed within a launch chamber that junctions with a pipe. A release valve is opened to allow the pig to enter the pipe. An exterior surface of the launch chamber can be heated to prevent the pig from sticking within the launch chamber or refrigerated to form the pig. The pipe pig can be propelled into the product stream or allowed to fall by gravity or suction alone. Articulations can also be formed into the pipe pig to allow the pig to bend along its length and so allow the pig to travel around elbows and bends in the pipe. Alternatively, a freezing agent can be injected into the pipe that contains the product stream to form the pig. With product recovery using the pig, piping system waste products are minimized. |
