Patent ID: 6009745
Filing Date: 2000-01-04
Classification: F28D,F28F,G01M

Abstract:
A method of locating a source of leakage or a crack in a heat transfer surface area of a plate heat exchanger between separate product and service fluid paths arranged in an intimate heat exchange relationship, the method comprises:circulating a solution through one fluid path of the exchanger, the solution comprised of a solvent and a solute in the solvent which has an appreciable vapor pressure under the chosen test conditions;providing a gas flow across another fluid path of the exchange surface by means of at least one of forced and natural convection;applying a positive pressure differential between the solution and the gas flow; anddetecting visually a leakage location from solute deposited at the leakage location upon evaporation of the solvent said solute undergoing an increase in amount deposited as the solvent evaporates and forming an increased surface area aiding in further deposition of said solute and the increased amount of said solute also acting to promote a wicking action to draw leaking solution through the crack.