Philip Vella, VRTX Technologies, Schertz, TX USA
Co-author(s): Peter Koestler, The Gambrinus Company, San Antonio, TX, USA
ABSTRACT: VRTX Technologies implemented the use of non-chemical technology for the treatment of cooling water from evaporative condensers at a brewery that has three evaporative condensers with a total cooling capacity of 1,500 tons. The technology used is controlled hydrodynamic cavitation (CHC). CHC is one of the most innovative technologies employed today and is unlike all other non-chemical technologies currently available. CHC provides scale, corrosion, and microbiological control in addition to water conservation and reuse options. In order to minimize the volume of water being discharged to the sewer, most evaporative cooling systems use a chemical scale inhibitor to prevent calcium deposits from building on those heat transfer surfaces. Eventually the water becomes so concentrated that chemical addition is no longer effective. The water is purged to the sanitary sewer and ultimately ends up at a wastewater treatment plant. Established in 1909, the Spoetzl Brewery, Inc. in Shiner, TX, is Texas’ oldest independent brewery. The original chemical water treatment system used four different chemicals to maintain proper operation of the system. Sulfuric acid was added to prevent calcium carbonate buildup. Chlorine and a non-oxidizing biocide were used to control microorganism growth and as a corrosion inhibitor to reduce corrosion rates. In conjunction with the chemical treatment, cycles of concentration (COC) were kept low with an average around 2. Despite these efforts, significant calcium carbonate deposits accumulated on and around the condenser tubes and inside the condensers. Based on the poor performance of chemical treatment it was replaced by a CHC system. There were five objectives to the study: 1) provide scale, corrosion, and microbiological control, 2) improve condenser operating efficiency over the existing condenser systems, 3) conserve water by minimizing condenser makeup discharge, 4) produce a reduced quantity of condenser bleed that possesses minimal pollution, and 5) implement environmental improvements and worker safety wherever possible. With the CHC system in operation it was determined that the daily makeup water declined from an average of 19,251 to 12,619 gal/day, representing a 34.5% reduction. Daily blowdown declined from an average of 8,417 to 1,657 gal/day, representing a 80.3% reduction. The average COC increased from 2.3 to 7.6 resulting in an annual water saving of over 2.0 million gal. An added benefit to the water savings from CHC is that the facility has removed chemical addition from its water treatment program, including acid, resulting in a safer and more environmentally friendly workplace. Also, since the blowdown is free from any added chemicals it may be able to be used for landscape irrigation or exempt for NPDES permits.
Phil Vella received his Ph.D. degree in chemistry from the University of New York at Albany. He did his post-doctoral work at Argonne National Laboratory in Illinois. Phil is currently the technical director for VRTX Technologies. He is responsible for providing technical support in the cooling water treatment area and directing research and applications development using controlled hydrodynamic cavitation (CHC) for wastewater, produced water, biofuels, remediation, drinking water treatment, and other environmental areas. Prior to joining VRTX, he was the manager of technology support for Carus Corporation. His technical responsibility was in oxidation chemistry, including the application of ozone, hydrogen peroxide, AOP processes, and chlorine dioxide, with emphasis on permanganates used in the municipal drinking and wastewater markets, industrial applications, and for the remediation of contaminated soil and groundwater. In addition, he was responsible for phosphate products used for corrosion control and sequestration in drinking water systems. In his 25 years in the water industry he has more than 60 publications and presentations worldwide, 4 patents, and has participated in numerous technology transfer seminars. He is a member of ASHRAE, AWT, RETA, AWWA, and WEF.