Smith Designs Custom Water System for CooperVision in Costa Rica
CooperVision, one of the world’s leading manufacturer of soft contact lenses and related products, was in need of a water purification system for their plant expansion in Coyol, Costa Rica. Smith Engineering’s VP, Bob Lucas, along with Xavier Morice, owner of Smith Engineering’s Central American affiliate, Aquametric SA, made a site visit to assess the requirements of CooperVision.
Smith Engineering Design Engineer, Jake Weiers, designed the 20 GPM RO/20 GPM CEDI system to fit CooperVision’s specific needs. The greatest challenge with this project was the high level of silica in the source water. High levels of dissolved silica create issues at many water treatment steps but especially with RO membranes. The levels were so high fouling that the membranes were a legitimate concern.
Because the membrane fouling occurs when silica is super saturated and comes out of solution, it was decided the most logical path would be to find ways to keep the saturation percentage down and keep silica in solution longer. In order to accomplish this, the percentage of reject water was increased. This kept the concentration down by means of dilution. Secondarily, the pH of the incoming water was adjusted to a higher level.
Silica is more soluble at a higher pH. This allowed operation at a higher concentration. The water system is now capable of running on source water with a higher than normal silica concentration. Balancing the pH and reject water allowed for an operating condition that the customer was pleased with. These design changes prevent premature RO membrane fouling which was critical to CooperVision as they have a history of replacing RO membranes annually with their existing water system.
An additional design challenge was the limited space available. Bob Lucas stated, “Our design group did a fantastic job of shrinking the footprint of this system through 3D Modeling. This might be the tightest package for a system of that size I have ever seen us build.”
Xavier Morice commented on the customer’s satisfaction, “The CooperVision plant manager is very happy with the performance of the new water system, not to mention the expected annual operating cost savings and downtime reduction.”