US 7,435,373 B2Granted

Apparatus and method for thermal de-burring of slotted well liners

AssigneeRegent Technologies Ltd.

InventorMike Claerhout

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Abstract

A method and apparatus for removing burrs from inside slotted metal liners exposes the burrs to a high-intensity gas flame that effectively oxidizes or incinerates the burrs, without inducing undesirable temperature levels in the parent metal of the slotted liner. This is accomplished using a torch head assembly having multiple gas torch nozzles disposed radially around the circumferential perimeter of the torch head, such that when the torch head is passed through the interior of a slotted liner, the flames are directed toward the interior surface of the liner. Auxiliary oxygen is introduced at the nozzle outlets, resulting in a large increase in flame velocity and intensity and, in turn, an increase in the flame temperature. The auxiliary oxygen may be introduced through annular passages surrounding the nozzles, such that the auxiliary oxygen effectively forms a cylindrical curtain surrounding the flame at each nozzle.

A de-burring apparatus, for removing burrs from interior surfaces of a slotted metal liner, said apparatus comprising:

(a) a torch carrier body having a front end and a rear end;
(b) a torch head connected to the torch carrier body at the front end thereof, said torch head having a longitudinal axis and a circumferential lateral surface, said torch head having formed therewithin:
b.1 a fuel plenum, for receiving a fuel mixture comprising a combustion gas and a primary oxidizing gas;
b.2 an auxiliary plenum, for receiving and conveying an auxiliary oxidizing gas from a source of auxiliary oxidizing gas;
b.3 a plurality of fuel channels, each fuel channel having an outer end and an inner end, and each fuel channel at its inner end being in fluid communication with the fuel plenum;
and
b.4 a plurality of nozzle ports, each nozzle port extending inward from the circumferential lateral surface of the torch head and having an inner wall surface, and each nozzle port being in fluid communication with a corresponding one of the fuel channels;
and
(c) a plurality of torch nozzles, each nozzle having an outer end, an inner end, and a side surface, an inner end, and each nozzle having a fuel passage extending through the nozzle between said inner and outer ends;
said apparatus being characterized by:
(d) each nozzle being retainingly installed within a corresponding nozzle port and defining an interstitial space between the side surface of the nozzle and the inner wall surface of the nozzle port, said interstitial space having an outer end in proximity to the outer end of the nozzle;
(e) the outer end of each nozzle extending close to or beyond the circumferential surface of the torch head;
(f) the inner end of each nozzle being sealingly engaged with the fuel channel associated with the corresponding nozzle port, such that the outer end of the fuel passage of each nozzle is in fluid communication with the fuel plenum;
and
(g) each interstitial space being in fluid communication with the auxiliary plenum, and intercepting the circumferential surface of the torch head, such that auxiliary oxidizing gas can flow from the auxiliary plenum into the interstitial spaces and exit at the outer end thereof.

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Abstract

Claims38