US 8,234,911 B2Granted

Method and apparatus for detecting a leak in a double pipe

AssigneeAreva Np

InventorPeter Jax

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Abstract

In a method for detecting a leak in a double pipe, a medium located in an intermediate chamber between the interior and exterior pipe is moved toward a first end of the pipe, whereupon the medium flows in from the second end. On the first end the medium is examined for any leakage of a characteristic material, upon the detection of which a leakage signal is generated and a location of the leakage is calculated based on the transport time of the characteristic material from the leakage to the first end and on the mass flow of the medium. A corresponding device contains a conveyor unit for moving the medium through the intermediate chamber. A material sensor is disposed at the first end for examining the medium for the characteristic material. A control and analysis unit is provided for generating a leakage signal and calculating the location of the leakage.

Claims9

Dependent claims

A method for detecting a leak in a double pipe, with the double pipe having an internal pipe and an external pipe surrounding the internal pipe with a gap, which comprises the steps of:

filling the gap with a medium;
moving the medium in the gap in a longitudinal direction of the double pipe to a first end of the double pipe, with the medium subsequently flowing in from a second end;
acquiring at the first end and at the second end, in each case a first mass flow and a second mass flow for the medium flowing into and out of the gap;
investigating, at the first end, the medium for a substance which is characteristic of a leak;
producing a leakage signal if the substance is detected in the medium;
ascertaining a transport time of the substance from the leak to the first end as a time difference between switching on a conveying device and detection of the substance;
ascertaining a point of the leak on a basis of the transport time and on a basis of the first mass flow and second mass flow of the medium;
and
ascertaining, in a case of the leak, a loss rate of the substance which flows through the leak on a basis of the first mass flow and the second mass flow.

6 more elements

Dependencies are inferred from the claim text.