Sherwin Williams Automotive Paint Facility, supplying products to the refinishing and collision markets, had used a thin film evaporator (TFE) to recycle their clean up solvent. The TFE had the capability to handle as much as 500 gallons per hour; however, variables in the dirty solvent stream made the process very labor intensive in that an operator was needed continuously to control the unit as the various combinations of solvents and paints were processed. Because the unit at this facility had been in service a number of years and needed continual repair, the plant’s maintenance department logged many hours of overtime, including working weekends to keep the TFE operable during the week.
Compounding the problem, Sherwin Williams was expecting growth in their product line which would increase their waste solvent volume to 800 gallons per hour. An additional TFE was considered, but the high initial capital cost and the plant’s experience with their TFE caused them to seek another solution. In evaluating alternative solutions, Sherwin Williams looked for a technology that would be versatile enough to handle the wide range of resins and variable solvent blend used at the facility. In addition, they wanted the unit to run virtually by itself to free up personnel for other duties. To bolster their confidence level, they were also looking for a vendor with demonstrable experience with a system with the plant’s expected volume capacity and the automation they required.
The answer to the problem was found in a solvent recovery system engineered and built by Progressive Recovery, Inc. (PRI). To demonstrate the viability of the PRI technology, a field visit was made to a plant that supplies OEM automotive finishes that had a PRI system of nearly identical design to the one proposed for the Sherwin Williams plant and had been in service for several years. That unit operated unattended and processes a highly variable blend of solvents, producing 5000 + gallons of clean solvent per day. During the ongoing discussion of the plant’s needs and wants, it was determined that the facility did not want one large distillation unit but two smaller ones with the total capacity to meet their needs. Having two systems gave them redundancy and prevented major problems if one unit was down for maintenance. This and other details relating to the equipment and operation were agreed upon and authorization was given to start the project.
Prior to the shipping date, PRI worked with the plant by supplying submittal drawings that included general arrangement drawings, a P&ID and Electrical Schematic. PRI also participated in a HAZ OPS meeting with plant and corporate personnel. After shipping, PRI Field Service Technicians were on hand to commission the system as well as train the plant operations and maintenance personnel on the recovery units.
The Sherwin Williams Plant now has a recovery system that has the capability of processing 800 + gallons of dirty solvent each hour and was done at an installed cost of roughly one-half of the capital price of a replacement TFE. Because of the fully automated features of the system, operator and maintenance costs have been practically eliminated. Reliability and recovery rates are so high that the volume of waste sent off-site has been greatly reduced and clean-up solvent purchases have also declined.
Recycling solvent on-site is the most economical, environmentally correct, and responsible choice that a firm can make. The larger the volume to be recycled, the shorter the payback. Economic payback under one year is not uncommon, with most units falling in the one to two-year range when all installation costs are included.