Plate Cleaning

Mineral scale from hard water dissolves in an acid wash, while protein, fat and biofilm respond to an alkaline detergent, often followed by an acid rinse. Order matters on mixed deposits, since an organic layer can shield the scale beneath it. Before switching cleaners, check them against both the gasket compound and the plate alloy, because a product that removes the deposit can still attack either one.

Use soft nylon brushes and a low pressure water rinse, and lay the plate flat on a support rather than working on it while it hangs. Wire brushes, steel wool and scrapers cut the surface and leave sites where deposits grip faster next time. High pressure water aimed at the gasket can lift it from the groove, so keep the spray on the heat transfer area.

Cleaning depends on chemistry, temperature, time and shear at the plate surface, and shear comes from velocity. A cleaning pump smaller than the process pump leaves the far channels barely touched and their deposits intact. Plan the CIP circuit to match or excede process flow through the pack, and watch the outlet temperature during the wash to confirm the whole pack is reached.

Many plants do exactly that on critical duty, holding a second plate set so the frame closes again quickly. The removed plates are then cleaned, inspected, regasketed and stored ready for the next swap. A spare set must match the frame's pattern sequence, so order it against the serial number rather than by plate size.

Usually something in the cleaning is roughening the surface or leaving residue, such as abrasive tools, a chemistry that etches the plate, or incomplete rinsing. It can also mean the deposit is never fully removed, so each cycle starts from a thicker base. Compare the approach temperature right after each service, and if it stops returning to the baseline, open the pack and look.