| 摘要 |
A pipeline pig comprises a body (2) provided with means (3) for positioning the pig in a pipeline (1). The body (2) will permit the fluid transported in the pipeline to flow through the pig without creating a substantial pressure drop. The pig is provided with a turbine (8) driven by the fluid flow therethrough, the turbine in turn driving wheels (16) biased against the pipeline wall. The power transmission may be accomplished by a pump (11) driven by the turbine (8), the pump output in turn driving hydraulic motors (14) connected to the wheels (16). An hydraulic cylinder (17) connected to the pump (11) may be used for biasing the wheels (16) against the pipeline. The drive system is preferably reversible, so that the pig may move both with and against the fluid flow in the pipeline. The pig may carry instrumentation for checking the condition of the pipeline, and power to this instrumentation may be provided by a generator driven by the turbine (8). Both the instrumentation and the reversing mechanism may be controlled by acoustical signals or an electronic computer included in the pig. |
