A History of Tower TechPioneering an Industry: Temporary Cooling Towers
The Tower Tech Modular Cooling Tower
The Tower Tech Concrete Modular Cooling Tower
Temporary Cooling Towers, Part 2
Building a Customer-Driven Company
Tower Tech was founded in 1985 by Mr. Harold D. Curtis, an inventor with nearly two decades of experience in the cooling tower reconstruction and erection industry. From 1985 to 1989, Tower Tech was one of a number of small, independently owned manufacturers of field-erected cooling towers.
Pioneering an Industry: Temporary Cooling TowersIn the late 1980s Tower Tech created a temporary cooling tower division in hopes that the pioneering effort would allow the company to compete in a market that was being choked by a lingering recession. In 1989, following a year of research and development, the first mobile cooling tower was finished at the company's plant in Chickasha, Oklahoma. The patented design met with resounding success and the fleet of mobile towers grew to a total of twelve by 1992, totaling 18,000 tons of mobile cooling capacity. In the event of an emergency, or if additional cooling capacity was required during the peak heat loads of the summer, mobile rental units could be put into service within hours.
Top of Page
The Tower Tech Modular Cooling TowerWhile highly successful, the rental fleet's primary use was for emergency tower replacement and for additional cooling needs at peak demand during summer months. In 1991, a decision to develop a packaged-tower line whose revenues would help offset the seasonal variation in revenues. Since there were dozens of cooling tower companies on the market, all of similar 'conventional' design, Tower Tech decided to develop a new generation of cooling tower that would be radically different and better than other manufacturers' towers. Different alone was not sufficient impetus for a customer to justify the purchase of a manufacturer's new tower line. It was imperative that the design significantly improves upon the hundred-year-old design philosophy that permeated the cooling tower industry.
Paralleling the development of the mobile tower, the new tower had to be packaged so that it could be delivered unescorted on a conventional semi trailer. In addition, it was decided that the new design should not require assembly by field personnel. These constraints forced the development of a new water distribution system to minimize the height of the tower. To this design objective was added a requirement to minimize the ability of the water distribution nozzle to clog. This was essential since a primary deficiency of conventional nozzles is their tendency to clog, especially in dirty-water applications and in applications where bacteriological growth is likely to form. Since cooling tower nozzles are designed for a primary flow rate, and performance drops off dramatically at off-design points, it was apparent that a design that would maintain hydraulically-uniform water distribution at varying flow rates would have exceptional market potential. The design that resulted, the Rotary Spray Nozzle, achieved a low water profile by employing a lateral spray pattern, provided essentially clog-free operation by incorporating a turbine into the nozzle, and maintained a spray pattern size and near constant pressure drop by use of an automatically-adjusting flow-sensitive orifice. The nozzle required less pressure head to since the turbine in the nozzle was a much more efficient device than the atomization approach used in a conventional fixed-orifice spray nozzle. Two patents on the design were awarded in the 1990s.
Another design shortcoming of 'conventional' cooling towers is their cold-water collection basins. These open basins tend to accumulate trash, are exposed to direct sunlight, and contain regions of stagnant water. In combination, these can lead to excessive sediment build-up and increase the need for algaecides and biocides. Further, a water free-fall rain zone above the basin that allows airflow into the tower is an integral part of conventional tower designs. This is an inefficient part of the cooling tower from a thermal perspective since the cooling achieved in ten feet of rain zone could be had in less than a foot of fill media. Further, the pump energy required to lift the hot water above this rain zone is used extremely inefficiently.
Tower Tech's enclosed, elevated-basin design is called a Flow-Thru Basin. This design feature eliminates most of the problems associated with conventional basins and removes the inefficient free-fall rain zone. Pump energy requirements were reduced, basin maintenance was virtually eliminated, and there was a reduction in algaecide use since the basin water was not exposed to sunlight. In addition, the Flow-Thru Basin significantly reduced the amount of dirt and trash that is typically blown into an open basin. The self-cleaning nature of the Tower Tech Flow-Thru Basin eliminated the build-up of sludge, common in stagnant regions of most towers. Bacteria, such as Legionella, can remain protected from chemical attack under this sludge.
The Flow-Thru Basin on the Tower Tech design was made possible by the invention of a system of water collection channels above the fans. These channels move the water laterally from the bottom of the fill to the enclosed basin while still allowing air into the fill. Patents on the Water Collection System were awarded in the 1990s. The installation of the Water Collection System creates a dry region under the tower. This allowed for the removal of the fan from the moist, hot air stream on the top of the tower. Placement of the tower mechanical equipment at ground level increased the longevity and maintainability of the equipment.
To add flexibility to the modular design, a number of small fans were used instead of a few large fans. This made motor replacement less expensive and the increased number of fans typically doubled the number of fan set points, allowing fan power to more closely match the changing heat load. The performance of the new modular design was optimized by the installation of relatively small motors that were installed vertically (shaft down), and fans were direct-drive, which obviated the need for gear reducers, driveshafts, couplings, or pulleys.
The original modular tower's walls and structural members were manufactured of hand-laid fiberglass components. Fiberglass was employed to eliminate the possibility of corrosion that is typically encountered on galvanized towers. The first hand-laid fiberglass tower was built in 1992. From 1992 to early 1994, more than 130 hand-laid fiberglass towers were produced and either rented or sold. Most of the development work and tool costs associated with the tower were financed by the sale of the mobile tower fleet in 1992.
While successful, the hand-laid tower proved too costly to manufacture. Extensive manpower was required to construct the tower and the reliance on man-made parts also made it difficult to maintain consistent tolerances. Also, the added cost of hand-laid fiberglass priced the tower on the high end of the market. To counter this fundamental drawback, the decision was made to change from a hand-laid fiberglass tower to a pultrusion fiberglass design.
An initial public offering of the company's stock was made in 1993 to finance the redesign of the modular tower. A rotational mold and several pultrusion, injection and fiberglass fan stack molds were designed and built. The plastic parts were made of corrosion-resistant ABS, glass-reinforced nylon, and polyethylene. At the time, the fiberglass parts were the largest pultruded profiles in the world and Tower Tech was awarded the Composite Structures Association Excellence in Innovation award in 1995. A patent for the pultruded, elevated basin was awarded in the 1990s. The first pultruded fiberglass tower was sold in 1994.
Much of the success of the fiberglass tower can be attributed to the company's decision to have the Cooling Technology Institute (CTI) certify thermal performance in 1993. An annual retest by CTI has maintained the certification continuously since 1993.
Top of Page
The Tower Tech Concrete Modular Cooling TowerA majority of the package cooling towers sold by the cooling tower industry are used in the commercial (comfort cooling) segment of the market. Until the 1990s, it was generally thought that packaged towers did not lend themselves readily to larger industrial and utility applications, so in 1994 Tower Tech developed a modular concrete cooling tower using a design similar to its already successful factory assembled fiberglass modular cooling tower. Concrete tower cells could be erected using any of the three common construction methods: cast in place, precast, or tilt-up. In all three variations, concrete columns and walls defined the perimeter of each cell, and concrete troughs on the exterior or the interior of each tower cell channeled cooled water from the Water Collection System into a grade-level cold water reservoir situated at the end of a row of tower cells. The Water Collection System rests on the concrete troughs, however due to their expanse, they are also supported from above, within the tower cell. The water distribution systems are constructed either of concrete-encased pipes or of PVC piping. The tower mechanical equipment is mounted on a concrete post or lintel beneath the tower. This arrangement provides for the same easy access and rapidity of maintenance found on Tower Tech's line of factory assembled modular cooling towers. The Tilt-Up Concrete Association's presented its Innovation in Design Achievement Award to Tower Tech in 1995, and method patents on the concrete tower design were awarded to Tower Tech in 1996. Tower Tech sold and erected its first concrete tower in 1995, and by 2001 more than a hundred concrete modular cooling towers had been erected worldwide.
Top of Page
Temporary Cooling Towers, Part 2By 1998, Tower Tech's phenomenal pioneering success in the temporary cooling tower industry had attracted dozens of competitors. And yet, Tower Tech's "fleet" of temporary cooling towers had more cooling capacity than all the other cooling tower rental companies' combined fleets. By 1998, Tower Tech had more than 160 modular cooling towers dedicated to temporary projects across North America. After completing a temporary project that year which required 80 large tower modules, Tower Tech sold its temporary cooling tower division to a competitor, entering into a five-year non-competition agreement and 10-year licensing agreement in that transaction. Those agreements expired in 2003 and 2008, respectively, and Tower Tech re-entered the temporary cooling tower industry in 2003. Tower Tech adds new cooling towers, pumps, piping, and electrical equipment to its fleet each year and currently boasts 70,000 cooling tons (210,000 GPM) of cooling tower capacity which is rented and leased to customers worldwide.
Top of Page
Accessory PartsWhen equipped with optionally available Tower Tech electrical control panels and variable frequency drives, Tower Tech modular cooling towers allow for more operating scenarios and flexibility, more energy opportunities, and greater built-in redundancy, than are available with any conventionally designed cooling tower.
Top of Page
Temporary SetbackFrom 1999-2001, in an attempt to reduce manufacturing costs, Tower Tech built approximately 156 factory-assembled cooling towers having plastic walls. Some of those units experienced problems, especially related to improper selection of sealant compounds. Tower Tech worked with those customers to resolve those issues, and today some 140 of those plastic towers remain in operation. However, those product issues eroded customer confidence and resulted in accumulation of heavy debt, and by late 2000 the company's chief executive officer had decided to resign for the good of the company and the technology to which he had given birth.
Top of Page
Building a Customer-Driven CompanyIn late 2000, Tower Tech's board of directors elected Robert Brink as the new chief executive. Despite the aforementioned product problems, Brink, who had led the company's rapid sales build-up from 1995, remained convinced that a market for Tower Tech technology still existed. He believed customers with high-value and mission-critical applications would continue to seek out and specify high quality mechanical equipment that can reduce costs. Brink focused his team on improving and reintroducing the company's line of heavy-duty fiberglass modular cooling towers that had met with such fine market acceptance from 1994 to 1998.
Tower Tech's board of directors authorized Brink to restructure or reorganize the company. Before doing so, Brink solicited the advice of customers who had been affected by the aforementioned quality issues. He then formed a permanent Customer Advisory Board which is comprised of five or more high-profile customers. The CAB gives direct feedback to Tower Tech senior management in the areas of product design, materials of construction, general quality management, staff education, and other matters. Brink also sought advice from shareholders, suppliers, creditors, and employees. After learning of Brink's plan to discontinue production of the plastic cooling towers and reintroduce the once-successful fiberglass tower line, the company's longtime investor group agreed to fund operations through a reorganizational process. Tower Tech filed a voluntary petition with the U.S. Bankruptcy Court in December 2000. Tower Tech emerged from Chapter 11 on February 1, 2002. Management credits the rapidity and success of this reorganization to the support of the company's loyal customers, shareholders, suppliers, creditors, and associates.
In 2001-02, Tower Tech adopted Lean Enterprise principles and implemented a company-wide quality management process. Product designs were further improved, non-essential assets were abandoned, and the manufacture of most component parts was outsourced. Senior management became deeply committed to the continuous improvement of products, processes, and people. Most Tower Tech associates have attended several Lean Enterprise and Six Sigma workshops and earned Six Sigma Black Belts, Six Sigma Green Belts, and received other industry recognition. All Tower Tech associates are encouraged to attend college and pursue other avenues of professional growth. And virtually all Tower Tech associates have attended Tower Tech University's seven certification courses which emphasize cross-pollination of the company's various work disciplines.
Today, Tower Tech manufactures only TTXL Series Modular Cooling Towers. These highly refined, premium fiberglass cooling towers have, as a standard offering, engineering certifications covering Zone 4 seismic restraint and 150 MPH wind loading. Acoustic certifications are also available. Too, as with all Tower Tech Modular Cooling Towers produced since 1993, the thermal performance of all TTXL Series Modular Cooling Towers is certified by the Cooling Technology Institute (CTI).
In 2008, Tower Tech relocated its headquarters offices and plant operations to a larger facility in Oklahoma City, Oklahoma, USA.
Over the course of two decades, Tower Tech has grown from a small wooden cooling tower constructor to a mid-sized manufacturer that's well known for offering innovative cooling towers that are easy to install and that offer ultra-low operating costs, excellent maintenance and safety characteristics, unmatched redundancy, and long service life. Tower Tech enjoys a niche in the comfort cooling market, process market, and co-generation market. The company's revolutionary design has been accepted by numerous offshore companies who now promote Tower Tech technology in their respective countries and regions.
To date, Tower Tech and its international network of partners have sold more than 2,500 factory assembled modular cooling towers valued at more than $250 million.