The Dow Chemical Company (Midland, Mich.; www.dow.com) has awarded Veolia Water Technologies (Moon Township, Pa.; www.veoliawatertech.com) a contract for a total overhaul of the process-water treatment plant at Dow’sPittsburg Operations facility in California. The technologies chosen were Veolia’s proprietary Multiflofor softening and HPDMVR Evaporators.
Dow has been investigating the replacement of an existing process water treatment system at its Pittsburg facility in California as the current system has come to the end of its life cycle.
The first stage of this new Veolia system is the Multiflo process. This is a high-rate chemical softening technology that features a modular multi-stage softening design that reduces installation costs. It is also said to be more resistant to process upsets than a conventional reactor or clarifier system.
The feed to the process water treatment system exhibits seasonal variations in flow and composition. The plant has existing tankage to provide buffer capacity to moderate variations in softener feed flow. In order to accommodate the specified flow variation, two HPD Evaporators were proposed, each with the capacity to accommodate 50% of the maximum design flow rate. These two evaporators used after the softening process use a Mechanical Vapor Recompression (MVR) configuration.
These HPD MVR Evaporators enable a high-quality recovered water stream to be produced and utilized as makeup water for the upstream processing facility onsite. This is especially important to Dow due to the location of the plant.
Veolia Water Technologies, Inc. CEO, Klaus Andersen, explained: “California’s water scarcity means water restrictions are quite common for many industrial operations. The solution that Veolia put forth will reduce the overall amount of water used by the facility and thus reduce its environmental impact. Long term, it will also be more economical for Dow.”