The industrial manufacturing industry has long embraced powder coating as the preferred method of applying paint to finished metal surfaces. A reduction in production costs, better coatings with improved corrosion protection, and the reduction of VOC emissions are some of the advantages. First developed in the late 1960’s, powder coatings work by applying a positively charged, dry, free-flowing powder to a grounded metal substrate. Curing in an oven allows the powder to flow together and form into a durable film after cooling.
When production requires small batches and non-continuous runs, the least efficient component of the process is the heating of both the curing ovens and pre-treatment solution tank. Rinsing the metal to be power coated with a pre-treatment solution is important because it ensures a uniform application. PB Metal Finishing Systems has designed a method of increasing the energy efficiency of production using their new Spray Save system.
The Spray Save system’s innovative solution takes advantage of available oven space by adding a heat exchanger to capture latent heat that would otherwise be wasted. The system is comprised of a closed, coupled pumping system that is fully valved and controlled complete with non-return valves. “Pre-treatment solution is taken at a low level from the tank thereby circulating the coldest area of the tank and also keeping the solution in movement and is then pumped through the stainless steel schedule 10 fully welded and tested heat exchanger. The return of the solution is passed back to the process tank continuously.”
At the beginning of the shift both the oven and pre-treatment tank burner should be switched on. Although the heat exchanger has the capacity to fully heat the pre-treatment tank, turning both on initially will save time. They estimate that during normal shift, the normal run rates of the pre-treatment tank heating can be reduced from 6.5 hour to only 1.5 hours. This happens without any addition load on the curing oven. This reduction in required heating translates into direct saving for operator.