Abstract: A portable apparatus and method for chemically cleaning a single pass plate and frame heat exchanger allows the cleaning solution to be uniformly distributed across the plate pack. This portable system of one pump of preferably 10-horsepower, capable of 300 gallons per minute flow through a discharge port; at least two distribution/collection tubes with apertures of predetermined diameter and predetermined placement; one reversing manifold; two bag filters; and one circulation tank with a capacity at least on the order of 150 to 200 gallons; attaches to a single pass plate and frame heat exchanger. The single pass plate and frame heat exchanger is configured with at least two removable flanges that, once removed, allow for the installation of the distribution/collection tubes. The apertures in the distribution/collection tubes are placed facing downwards depending upon the direction of the operational fluid to enhance a vacuuming effect for particle and debris removal during cleaning.