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Hwang, Charles J. McCloskey & John A. Hvizdos, Calgon Corporation 1990 Abstract: When managers of cooling water systems operations make decisions concerning a treatment approach for scale, corrosion or deposit control, economics often play a very important role. A treatment program must be economically justified before it is implemented, and managers traditionally strive to optimize cost without sacrificing performance goals and unit reliability. Many factors affect the operations of a recirculating cooling water systems and there are numerous components that comprise the total cost of a treatment program. However, when asked, "What is the cost?" of a given treatment program, the reply often centers on the cost of specialty chemicals used in the program. In fact, a closer look at the variables that affect the total treatment cost gives a more representative picture than specialty chemicals alone. Operating variable such as cycles of concentration and pH of recirculating cooling water and the acceptable level of corrosion inhibitors are important factors to be considered. "Cycles of concentration" of a recirculating cooling water system defines the material balance of a cooling water system, and directly affects a variety of make-up and blowdown related costs. Targeted recirculating cooling water "pH" not only dictates the cost of pH adjustment chemicals, but also influences the concentration of specialty chemicals required for the achievement of scale and corrosion inhibition goals. The acceptable level of "corrosion inhibition" itself can have a great impact on the amount of chemicals needed and, therefore, the treatment costs. This paper describes how decision makers can visually examine the impact of operating variables on various costs elements as well as total cost and quickly make an informed decision. Computer modeling of cost optimization and three-dimensional graphic display play a strong role creating "pictures" of the relationship between cost and operating variables. Cases of practical application in real-world setting using the computer-aided methodology are presented.
An Effective Method for Non-Chemical Control of Microbial Activity in John Dresty, Environmental Research Institute; James Fitzpatrick, Warner Lambert Corp. 1997 Abstract: This paper describes the methodology and results from a field test of a novel electric water treatment system for cooling towers. The technology has been widely used in Europe for over 5 years with success, and is now commercially available in the United States. The Cooling Tower tested was a new installation used to support shop air compressors in a manufacturing facility in Connecticut. The heart of the device is a variable high frequency transformer that imparts electrical energy to the cooling tower water. The system tested achieved high reliability from a patented data feedback circuit that constantly changes the applied voltage and frequency, based on the variable chemical and physical characteristics of the flowing water. The data produced, during the trial, showed excellent promise for non-chemical control of the bacteria and algae, and scale and corrosion prevention in cooling towers.
Get the Limits of Cooling Tower Design: Low Approach-Large Range-Cold Michel Monjoie, Hamon Thermal
Rob Schwalm, Barrick Goldstrike 1999 Abstract: Cooling 65000 GPM geothermal water from 140°F to 38°F with 29°F wet bulb was realized at Barrick Goldstrike mine using two - 10 cell - cooling towers running in series. The paper describes the cooling process, the cooling tower design, and the hydraulic design given safe and flexible operation, the winter operation and the test results.
Cooling Tower Water Conservation Using Solubility Chemistry Stephen E. Mitchell, S & S
Consulting Services 1999 Abstract: Evaluation and successful results of the use of a weak organic acid and amine compound to increase hardness salt solubility at alkaline pH levels in an open recirculating cooling system, which will allow higher cycles of concentration than standard acid and non-acid cooling water programs.
Automating the Cooling Water Triangle David L. Stonecipher, Steven R. Hatch, Daniel A. Meier, Barbara E. Moriarty, and Mita Chattoraj, ONDEO-Nalco Company 2003 Abstract: This paper will introduce a new cooling water approach that combines direct, real-time control of all three corners of the "cooling water triangle" with the appropriate chemistry solution and advanced communications and data management technologies. Three unique monitoring technologies will be presented and the corresponding control algorithms discussed. One molecular sensor directly and dynamically measures the actual system microbial activity (planktonic and sessile), the second sensor provides a surrogate for actual system deposition of scale and/or particulates, and the third sensor offers an improved LPR corrosion monitor. Field use of this new total cooling water management system will be discussed, including the benefits of improved system performance, better response to operational variability, 24/7 conversion of knowledge to value, and minimized operator involvement.
San Antonio Water System's Cooling Tower Audit Program Results In Significant Water Savings Eddie Wilcut, San Antonio Water System and John J. Sims, and Tory Tvedt, Puckorius & Associates, Inc. 2003 Abstract: The SAWS project to reduce fresh water use in cooling tower water systems was initiated in 1999. It has saved many acre feet of fresh water. This water savings to cooling tower users has provided other major benefits, which are outlined and discussed. The methodology utilized in this project is identified along with a number of case history examples.
Power Plant Restores Cooling System Performance With Bio-detergent Cleanup Charles W.H. Foster and Trevor Gent, ONDEO-Nalco Canada Company 2003 Abstract: Cooling tower performance deteriorates continuously over time, but only manifests itself as a problem during adverse ambient conditions. For a power plant this can have severe economic consequences as peak power demand coincides with the very ambient conditions that can limit cooling capacity and power output. This work documents the results achieved in a successful bio-detergent application at a 26 MW power plant.
Low Cost Cooling Tower Biocide Alternatives David Evans and Abdulaziz Turaik, Saudi Aramco 2005 Abstract: Saudi Aramco's Dhahran Utilities department is concerned about both biocide cost and biocide performance for the operation of its seventeen cooling towers (40 cells). The department tested alternative biocides and is now using an effective low cost biocide. Slug dosing calcium hypochlorite was used for many years for microbiological control on the cooling towers. The cost of the calcium hypochlorite was relatively low, however, when it was slugged dosed, the calcium hypochlorite oxidized expensive anti scalant, reducing heat exchanger protection. Therefore using calcium hypochlorite had a high overall cost. The department tested non oxidizing biocides to eliminate the anti scalant oxidizing problems. The non oxidizing biocides worked but they cost twenty times more than calcium hypochlorite. Also, the cooling tower operators did not like the safety concerns with non oxidizing biocides. The department successfully tested and is now using a low cost biocide that is normally used for swimming pools. Testing included microbiological test to confirm the biocides effectiveness.
Sewage Effluent for Cooling: A Forty-Year Experience in the Texas Panhandle Bernie Wieck, Universal Utility Services 2007 Abstract: Sewage effluent for cooling has been utilized in the Texas panhandle since the early 1060's. A history of cooling water treatment for electricity production, as well as recommendations for new installations will be presented.
The Conversion From Gas to Tablet Chlorination: A Case Study Austin Looper, PPG Industries
Billy Smith, ChemTreat, Inc 2008 Abstract: Chlorine gas is used extensively in large cooling tower applications, but the environmental and safety risks have left operators searching for alternatives. This paper will review a conversion from chlorine gas to calcium hypochlorite tablet feed technology on a gulf coast chlor-alkali plant cooling tower. The paper will exhibit, in detail, the impact on cost, corrosion, tower performance, calcium buildup, and safety and handling.