US 4,393,564 A · Method and apparatus for repairing heat exchangers

Abstract

A shell and tube type heat exchanger having a tube bundle supported at opposite ends in tube sheets is capable of being repaired quickly by closing off opposite ends of a damaged tube using the method and apparatus disclosed. The apparatus comprises a two-part tapered plug assembly which is adapted to be installed in the tube in alignment with the tube sheet and expanded radially outward into tight engagement with the interior of a tube by pulling an inner wedge portion of the plug assembly axially relative to an outer ring portion. The pulling is effected by an hydraulic ram which is connected by a breakaway unit to a pull rod which slides axially relative to a compression tube both of which are received axially within the defective tube. The hydraulic ram pulls the rod relative to the compression tube and thereby draws the wedge inside the ring until the breakaway connection releases the pull rod and enables the pull rod, compression tube and auxiliary parts to be withdrawn from the defective tube. A shorter length of compression tube and pull rod is utilized for plugging the other end of the defective tube and for plugging U-bend types of heat exchangers.

Claims15

Dependent claims

Apparatus for use in plugging a tube in a heat exchanger having a bundle of tubes mounted at opposite ends in spaced tube sheets comprising:

a plug assembly adapted to be installed inside one end of the tube in the zone of one of said tube sheets, said plug assembly including an expandable ring and a wedge mounted in the ring and slidable relative thereto to expand the ring radially outward against the inside of the tube;
breakaway means connected to said wedge and projecting into said tube;
pull rod means connected at one end to said breakaway means and extending lengthwise of said tube beyond the other of said tube sheets;
compression tube means engaged at one end with said ring and surrounding said pull rod means inside said heat exchanger tube and extending therealong from said ring into proximity with the other tube sheet;
ram means disposed adjacent said other tube sheet for applying tension to said pull rod means and compression to said compression tube means while maintaining said plug assembly aligned with its tube sheet;
whereby upon application of tension and compression the wedge is drawn into the ring until a predetermined outward pressure is reached causing the breakaway means to separate for affording withdrawal of the compression tube means and pull rod means from inside the heat exchanger tube.

3 more elements

A method of plugging a tube in a heat exchanger having a bundle of tubes mounted at opposite ends in a pair of tube sheets, comprising the steps of:

disposing inside said tube in the zone of one of said tube sheets a plug assembly having an expandable ring and a wedge within the ring connected to breakaway means coupled to pull rod means extending lengthwise in the tube,
disposing elongated compression tube means in said heat exchanger tube around said pull rod means and engaging one end against said ring,
providing exteriorily of said tube sheet ram means capable of being expanded axially of said tube,
connecting said ram means to said pull rod means and said compression tube means to cause tension to be applied to said pull rod means and compression to be applied to said expandable ring through said compression tube means, and
actuating said ram means for pulling said wedge into said ring and expanding said ring into tight engagement with the interior of said heat exchanger tube until said breakaway means ruptures.

2 more elements

Dependencies are inferred from the claim text.

Method and apparatus for repairing heat exchangers

Life of this patent

Method and apparatus for repairing heat exchangers

Life of this patent

Abstract

Claims15