System and method for cleaning a tube bundle of a heat exchanger core

A system for cleaning a tube bundle of a heat exchanger core, the system comprising:

• a lance for directing a jet of fluid into spaces between the tubes of the bundle in a direction transverse to the tubes of the bundle,
• a carriage for advancing the lance into the bundle,
• a mount movable relative to the carriage for holding the lance,
• a spring acting on the mount to urge the lance towards the tube bundle,
• a sensor for detecting relative movement between the lance and the carriage, so as to detect when a reaction force acting on the lance upon encountering an obstruction in the tube bundle exceeds a predetermined limit,
• at least two fixed members with a shaft extending therebetween and connected for movement with the carriage, and
• at least one slidable member connected for movement with the lance and slidable on the shaft,
• wherein the relative movement between the lance and the carriage is achieved by the at least one slidable member traversing the shaft,
• wherein the sensor is mounted to one of the at least one slidable members and senses its proximity to a rod in axial alignment with the sensor, and
• wherein the sensor used for detecting the reaction force is a proximity sensor.