Heat exchanger maintenance technique

摘要

A heat exchanger is cleaned, inspected and/or plugged while the heat exchanger is in operation. In some embodiments, the heat exchanger includes a channel cover having valve-seal assemblies allowing isolation tools to be inserted through the channel cover into sealing engagement with the ends of tubes to provide a flow path separate from the normal flow paths through the heat exchanger. Cleaning and/or inspecting can be done through the isolation tools and tubes that are leaking can be plugged through the valve-seal assemblies. In some embodiments, brushes are located inside the heat exchanger and can be independently advanced into cleaning relation with a large majority of the tubes.

主权项

1. A combination comprising
a heat exchanger comprising a pair of compartments, an array of closely spaced tubes having an inlet end opening into a first of the compartments and an outlet end opening into a second of the compartments, a channel cover closing an end of at least one of the compartments and providing passages directed at ends of the tubes, the tubes providing a first path of fluid movement therethrough, a second path of fluid movement being on an exterior of the tubes, at least a plurality of assemblies on the channel cover adapted to insert maintenance elements through the channel cover passages into the heat exchanger under pressure and minimizing leakage from the heat exchanger, and a maintenance element extending through at least one of the assemblies for conducting maintenance on one of the tubes, the assemblies including a seal adapted to seal on the outside of the maintenance elements and a valve, having a valve passage therethrough, between the seal and the channel cover, the valve comprising a valve seat and a valve member, the valve member being movable between a first position allowing movement of the maintenance element through the valve passage and a second position closing the valve passage after removal of the maintenance element, the maintenance element being movable axially through the seal toward and away from the tubes and being moveable through the valve passage in one direction and out of the valve in an opposite direction whereby the maintenance element may be removed from the heat exchanger compartment while the heat exchanger is under pressure, the assemblies being positioned and being adapted so maintenance elements can be inserted through the assemblies into at least 80% of the tube ends.