Case Studies

USA International Airport:
WSA Brush-type Automatic Tube Cleaning Systems (ATCS) were installed on the centrifugal and absorption chillers.  The two systems are returning the total cost of their original installation every year in energy and labor savings.  These savings are a direct result of reduced energy consumption and maintenance.  Prior to installation of the WSA Brush-type Automatic Tube Cleaning Systems the fouling factor was .0018 and two to three manual tube cleanings were required every year.  Since installation, fouling factors are less than .0002 and manual cleaning has not been required.

High Rise Commercial Building:
During June, July and August a major office building saved approximately $35,500.00 by reducing the steam required to operate their large turbine driven centrifugal chiller.  These savings were a direct result of a WSA Automatic Tube Cleaning System installed on the chiller condenser and steam condenser.  The WSA system prevents build up of deposits which waste energy by interfering with proper heat transfer.  The fouling factor is now maintained at or below the standard allowance provided by the heat exchanger manufacturer.

Chemical Company;
For years, operations were abruptly halted every three to four months for manual cleaning of the tubes on the 380-ton refrigeration unit serving a manufacturing unit at this chemical plant located in southern USA.  Routine monitoring of the temperature around the Freon condenser would indicate a gradual loss in heat transfer performance due to fouling of the cooling water tubes by hard scale.  This in turn was reflected by an increased electrical load on the refrigerant compressor of up to 18% due to a buildup of head pressure.  The product was in high demand, so it was preferred to keep the unit on-line as long as possible, with minimum number of shutdowns.  This meant the refrigeration system would continue operating until the compressor loading reached its limit forcing a shutdown for tube cleaning.  The plant operator had very little control over the timing of a scheduled shutdown.  The plant decided to install WSA’s Automatic Tube Cleaning System and since, there has been no unscheduled shutdowns to clean the condenser and the compressor loading has continuously been typical of a clean, start-up condition.  After one year of service, during the annual turnaround of the entire unit, an inspection revealed the tubes to be free of any fouling.  In fact, the tubes looked better than when they were rodded out just prior to installing the WSA Brush System.  The payback on this installation was less than one year and based on reduced annual power cost and savings in maintenance costs for the unscheduled cleanings.  Not included in these savings, but as significant was the fact that no production was lost due to condenser shutdowns.

Refinery
Refinery management reports markedly reduced steam consumption, tube fouling, and maintenance shutdowns by installing WSA Automatic Tube Cleaning Systems on the twelve condensers in steam turbine systems used to drive pumps and compressors throughout the refinery.  Prior to installing the WSA brush systems, it was necessary to shutdown a condenser every 6 to 8 months for cleaning the tubes because buildup inside the tubes caused heat transfer efficiency to drop significantly.  Now, with the WSA brush systems installed, no effects of fouling have been noted.   Their records show a significant cut in steam consumption and they have cost savings of 40,000 lb. of steam/hr of operation.  (Note: all surface condensers are in water service with water going through the tubes and steam condensing in the shell.)

Power
WSA Brush-type Automatic Tube Cleaning Systems (ATCS) are installed at many power plants within the USA and globally, including in this USA power plant at two stations:  Station #1 has WSA Brush-type Automatic Tube Cleaning Systems (ATCS) installed on the cooling systems of two (2) 850 MW peaking units, as well as in the 87.5 MW (summer net 70MW) run-of river unit. These cooling water circuits have not required chlorination other than for sanitary reasons.  This good performance is due to a combination of clean make-up, peaking service and use of the WSA Brush-type Automatic Tube Cleaning System(s).  Chronic back pressure problems and associated cleaning downtime has been eliminated. Because of this good success, this same power plant installed additional WSA brush systems in two more units and at another site; Station #2, to eliminate off-design back pressure conditions, etc. as well.  The positive change in turbine heat rate has proved a positive effect in reducing the operating costs of these stations, i.e. improving the Btu per kilowatt hour in overall heat rate.