Abstract:
A cooling tower structure and method of construction using multiples of standard concrete masonry units (CMUs) properly reinforced, using standard CMU construction methods and specifications, and using block masons of ordinary skill, costing less for construction and maintenance, requiring less heavy equipment, less transportation and lifting of heavy and large components, a smaller construction work site, and requiring significantly less time to construct and make operational.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention provides a method of constructing water cooling towers using concrete masonry units (CMUs) more quickly, at lower cost, requiring no heavy construction equipment, resulting in a more durable, fire-resistant, longer lasting and easier to maintain structure than is presently known. 
         [0002]    Water cooling towers are well known, and are a common heat-exchange component in large commercial, medical, and industrial HVAC systems, in cooling for industrial processes, and aeration of water for other purposes. Cooling towers are a standard part of new construction of buildings or campuses of buildings. Many existing buildings also need replacement or supplemental cooling towers because of the inadequacy of present cooling towers due to increased demands, higher temperatures, consolidation into campus-wide HVAC systems, or deteriorating performance of existing cooling towers. 
         [0003]    An under-performing cooling tower can be a large problem for commercial properties, medical facilities, and industries, affecting the efficiency and therefore the operating costs of HVAC and industrial systems, and affecting the comfort and therefore the satisfaction, health, and productivity of persons. Under such circumstances, existing cooling towers need to either be replaced or be supplemented with new cooling towers. But replacement requires taking an existing cooling tower out of service and waiting for the construction of a new cooling tower to be completed. And supplementation requires finding a new location for the new cooling tower, and then waiting for its construction to be competed. 
         [0004]    One common type of industrial cooling tower is a counterflow tower where water falls by gravity through fill media from water nozzles positioned in the upper part of the cooling tower. A water collector pan is positioned below the fill layer. The water is directed to a downstream water basin, from where it is re-circulated back into the spraying nozzles on top. A source of moving air is mounted on or in the cooling tower, directing the cooling air toward the water. 
         [0005]    Cooling towers exploit the evaporative cooling of water exposed to air. Therefore they are generally located outside. Cooling towers must provide a very large surface area for water to interact with air. Therefore cooling towers are very large structures—with at least a 20-square-foot footprint and at least 10 feet of height—and some many times that large. Powerful motorized fans are generally required to provide adequate air flow. Water is heavy, and powerful fans are heavy, and therefore cooling towers are heavy structures when in use, and the basic structure of the cooling tower must be capable of withstanding the internal forces of the heavy moving water and heavy moving fan, and the external forces of the outside environment. 
         [0006]    Cooling towers must be located outside, take up a lot of space, can be noisy, and might generate some mist or vapor. They are typically placed on the roofs of high-rise buildings or in otherwise out-of-the-way locations on the grounds or the campus. Such locations present problems in the construction and installation of cooling towers. A heavy crane might be necessary—for months—in order to lift construction materials or pump concrete onto a rooftop or into an inaccessible area at ground level. There might be very little adjacent “laydown” or staging area for construction crews, materials, and equipment. 
         [0007]    Industrial cooling towers made of wood in the traditional way are susceptible to fire and to rot and early deterioration in the constantly wet cooling-tower environment, requiring proper preparation and constant maintenance throughout the operational life of the cooling tower. 
         [0008]    Cooling towers made of steel are known, but are very expensive, very heavy to transport and erect, and require highly skilled workers in the design phase, any pre-fabrication phase, and in the erecting or construction phase, in order to avoid potential failure, improper fitting of components, or even injury to persons and property. Also, steel is subject to rusting and deteriorating in the constantly wet environment if it is not properly prepared and constantly maintained throughout the operational life of the cooling tower. 
         [0009]    Cast-concrete cooling towers can be built using the shuttering method, where sections of the building framework are built using wooden forms; then concrete is poured into the forms to make a first lateral row. After the concrete sets, the next lateral layer is formed, filled with concrete, and allowed to set. This process continues until the structure reaches the desired height. The construction of such a tower is a major undertaking requiring many months, even a year, to complete. The logistics and heavy equipment required are extensive. Such traditional towers have underground basins and require extensive engineering and design in advance of construction. 
         [0010]    Fordyce and Fritz (U.S. Pat. No. 3,834,681 A) teach an open-frame, prefabricated, concrete cooling tower structure. Furlong, et al. (U.S. Pat. No. 3,917,765 A) teach a cooling tower shell of factory-made pre-cast concrete parts. Curtis (U.S. Pat. No. 5,227,095 A) teaches a cooling tower system consisting of individual modules, which can be built from fiberglass in a factory and then transported to and erected on site. Curtis and Oberlag (U.S. Pat. No. 5,545,356 A) teach a method of constructing a cooling tower structure by casting the concrete walls on site in a horizontal position and then raising the walls to a vertical position—a “tilt-up” construction, or by pre-casting concrete modular wall units off-site and transporting and erecting them on site. 
         [0011]    There is some question whether “tilt-up” and some other concrete pre-fabrication methods are capable of producing stable structures generally. For example, concerns about, and even requirements to retrofit, such structures in earthquake-prone areas. 
         [0012]    Concrete pre-fabrication, like steel, requires highly skilled workers in the design phase, the pre-fabrication phase, and in the erecting or construction phase, in order to avoid potential failure, improper fitting of components, or even injury to persons and property. 
         [0013]    All of the presently known methods of constructing cooling towers have at least one of the disadvantages of being insufficiently durable, too expensive, too difficult to transport, too long to place into operation, too difficult to erect or construct without highly skilled labor and long-term use of heavy machinery, and too difficult to maintain over the operational lifetime of the cooling tower. 
         [0014]    Concrete masonry units (CMUs) and proper construction methods and standards for their manufacture and erection are known in other fields of construction. The advantages of CMUs include very low cost, greater strength at lighter weight than cast or pre-cast concrete, and the ability of masons of ordinary skill to quickly build structures according to already well-known methods. In CMU construction, hollow concrete blocks are reinforced with steel rebar or similar material and filled with concrete, mortar, or grout, with construction proceeding layer by layer, continuously, without having to wait for each concrete layer to set. 
       SUMMARY OF THE INVENTION 
       [0015]    The present invention provides a cooling tower constructed of multiples of standard concrete masonry units (CMUs) properly reinforced, using standard CMU construction methods and specifications, and using masons of ordinary skill, costing less for construction and maintenance, requiring less heavy equipment, less transportation and lifting of heavy and large components, a smaller construction work site, and requiring significantly less time to construct and make operational. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Reference will now be made to the drawings, wherein like parts are designated by like numerals, and wherein 
           [0017]      FIG. 1  is a partially exploded orthogonal perspective view of the invention and of the cooling components housed in the invention. 
           [0018]      FIG. 2  is a partially cutaway side perspective view of the invention and of the cooling components housed in the invention shown in place. 
           [0019]      FIG. 3  is a low perspective side view of the invention and of the cooling components housed in the invention as in use. 
           [0020]      FIG. 4  is a perspective view of the types of CMU components used in the invention. 
           [0021]      FIG. 5  is an illustration of the construction method for the deep lintel type of CMU used in the invention. 
           [0022]      FIG. 6  is an illustration of the construction methods of the use of reinforcing rebar and of temporarily supporting the deep lintel types of CMUs used in the invention. 
           [0023]      FIG. 7  is an orthogonal side view of the invention. 
           [0024]      FIG. 8  is an orthogonal top view of the invention. 
           [0025]      FIG. 9  is an orthogonal perspective side view of an embodiment of the invention. 
           [0026]      FIG. 10  is an orthogonal perspective side view of the foundation and embedded rebar and conduit of an embodiment of the invention. 
           [0027]      FIG. 11  is an orthogonal perspective side view of an embodiment of the invention. 
           [0028]      FIG. 12  is an orthogonal perspective side view of the foundation and embedded rebar and conduit of an embodiment of the invention. 
           [0029]      FIG. 13  is an illustration of the function of the invention in operation. 
           [0030]      FIG. 14  is a perspective view of an embodiment of the invention having two connected cooling towers. 
           [0031]      FIG. 15  is a perspective view of an embodiment of the invention having four cooling towers connected with the water-basins in the center. 
           [0032]      FIG. 16  is a perspective view of an embodiment of the invention having four cooling towers connected with the water basins to the outside. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0033]    Referring to  FIG. 1  &amp;  FIG. 2  the counterflow type of cooling system known in the art comprises, from top to bottom, an optional drift eliminator  54  for the purpose of catching sprays and mists of water and retaining them in the cooling system, a nozzle array  53  that sprays water to maximize the available surface area of water droplets for evaporative cooling, a thick layer of porous fill media  52  to further spread out the water droplets and to prolong their exposure to the cooling stream of air, and a water collector  51  that catches and channels the cooled water but allows the flow of cooling air from below. 
         [0034]    The forced-air counterflow type of cooling system known in the art further comprises a fan  22  driven by a fan motor  21  and surrounded by a fan shroud  24 , with the fan assembly located below the rest of the cooling system, which puts the fan assembly closer to the ground or mounting surface, which is advantageous for maintenance purposes and for weight-distribution purposes. See  FIG. 3 . 
         [0035]    The forced-air counterflow type of cooling system is necessarily very large, in order to move a great volume of air across a great surface area of water. The cooling system for which a preferred embodiment of this invention is designed is approximately 24 square feet across and 8 feet deep, with an approximately 20-foot fan. In order to move a sufficient amount of air, the fan  22  should be mounted far enough above the ground or mounting surface, and with as few structural restrictions as possible, in order to provide an open chamber  18  allowing sufficient air intake. 
         [0036]    Water is heavy, and 20-foot fans are heavy, so cooling systems are heavy. The forced-air counterflow type of cooling system is therefore a very heavy structure that must nevertheless be mounted high off the ground or mounting surface, and remain stable for many years of operation despite internal stresses from the constant movement of water and air and the machinery that moves them, and external stresses from weather, maltreatment, accident, or other circumstances related to the cooling towers being placed outside on rooftops, in parking lots, or in other exposed places. 
         [0037]    Every millisecond throughout its several-decades operational life, a cooling-tower structure is required to keep a wet, heavy, shaking machine nine feet higher off the ground than gravity would have it be. 
         [0038]    Although a stable cooling tower structure might be achieved by adding to and reinforcing the supporting structure below the level of the fan, adding more material in that area would inevitably reduce the air intake flow. The requirements for strength and stability run counter to the requirements for height and openness. This invention solves that problem. 
         [0039]    Cooling towers present another conundrum; they are usually located in places where it is difficult to set up a construction project and difficult to move materials and heavy equipment. This invention solves that problem, too. 
         [0040]    Presently known cooling tower structures and methods of construction largely comprise some type of cast concrete or pre-cast, pre-stressed concrete either as large components or as pre-fabricated sections. It is difficult to move large amounts of just-mixed concrete from several trucks at street level up to the rooftop of a tall building, and even where access is not so limited, pouring concrete has to be done in stages and requires a lot of time for completion. Moving large concrete components and pre-fabricated sections to the rooftop of a tall building or other inaccessible or constricted location is similarly difficult and expensive. This invention solves that problem, too. 
         [0041]    The present invention is a cooling tower structure  10  made entirely of multiples of 6 sizes or styles of standard CMU concrete blocks  71 ,  72 ,  73 ,  74 ,  75 ,  76 , reinforced and installed using standard materials and methods. See  FIG.4 . The CMUs are cheaply and readily available everywhere, and a large number of masons everywhere know how to install them properly. CMUs, especially the autoclaved aerated ones, are relatively light for their strength, and can be handled by the single unit or reasonable-sized groups of units, and therefore can be transported, stored, and placed into position much more easily than other building materials. 
         [0042]    In a preferred embodiment,  FIG. 9 , the cooling tower structure is 30 feet in the longer horizontal dimension, which includes the water basin  40  or reservoir, 26 feet in the shorter horizontal dimension, and 18 feet tall, supporting the fan  22  at about 9 feet off the ground surface and the other cooling-system elements above the fan. This embodiment accommodates a cooling system 24 feet by 24 feet wide and up to 10 feet deep, having a fan size of up to 24 feet, although a 20-foot fan would probably be sufficient. This embodiment uses 1576 8-by-16-by-8-inch CMUs  71 , 26 8-by-8-by-8 CMUs  72 , 234 deep-lintel 16-by-8-by-8 CMUs  74 , 6 corner 16-by-8-by-8 CMUs  75  for terminating some of the bond beams  30 ,  37  perforated 8-by-8-by-8 CMUs  73  which allow collected cooled water to flow into the basin  40 , and 209 capping 1-by-8-by-8 CMUs  76 . Other than the reinforcing rods  90  and the cement  78 , mortar, or grout, no other construction materials are needed except for fasteners to support and secure the cooling system in place in the cooling tower. 
         [0043]    In a smaller embodiment,  FIG. 11 , the cooling tower structure is 18 feet in the longer horizontal dimension, 14 feet in the shorter horizontal dimension, and the same 18 feet tall, supporting the fan  22  at about 9 feet off the ground surface and the other cooling-system elements above the fan. This embodiment accommodates a cooling system 12 feet by 12 feet wide and up to 10 feet deep, having a fan size of up to 12 feet, although a 10-foot fan would probably be sufficient. This smaller embodiment uses 918 8-by-16-by-8-inch CMUs  71 , 27 8-by-8-by-8 CMUs  72 , 126 deep-lintel 16-by-8-by-8 CMUs  74 , 6 corner 16-by-8-by-8 CMUs  75  for terminating some of the bond beams  30 , 19 perforated 8-by-8-by-8 CMUs  73  which allow collected cooled water to flow into the basin  40 , and 119 capping 1-by-8-by-8 CMUs  76 . 
         [0044]    In other embodiments, cooling tower support structures can be built or added onto together, sharing common walls, in several configurations.  FIG. 14  shows a two-tower configuration having a footprint of 30 feet by 51.3 feet and requiring 2838 of the large CMUs  74 .  FIG. 15  &amp;  FIG. 16  show four-tower configurations having footprints of 51.3 feet by 59.3 feet and requiring 5214 of the large CMUs  74 . 
         [0045]    The large, unobstructed open chamber  18  of the invention is made possible by the use of very long bond beams  30  or lintels, spanning, for example, 22 feet each in 3 spans of a preferred embodiment. 
         [0046]    Referring to  FIG. 5 , the cooling tower structure comprises six lateral bond beams  30  or lintels constructed from deep lintel CMUs  74  having a deep “U” shape that accommodates the placement of a reinforcement bar  90  such as steel rebar in a horizontal orientation spanning and connecting or bonding the units, and filling with cement  78 , mortar, or grout in order to secure the CMUs  74  and the reinforcement bar  90  in place. Where a deep lintel CMU  74  sits over another CMU, such as at a corner, it can be vertically secured by placing a reinforcement bar  90  through a notch  77  in the face of CMU that is mounted downward. 
         [0047]    Referring to  FIG. 6 , during construction of the lateral bond beams  30  or lintels, the blocks over the span can be temporarily supported with material such as lumber, such as 2-by-4 lumber  79 . Such temporary support is only needed while the cement  78 , mortar, or grout sets up and secures the supporting material. With such a temporary support, the placement of courses of CMUs above the bond beams  30  is allowed to proceed without waiting for any set-up of the bond beam. Alternatively, the bond beams may be constructed on an adjacent flat surface and subsequently hoisted into place. 
         [0048]      FIG. 13  illustrates the normal use of the cooling tower structure with the cooling system in place. The fan motor  21  and fan  22  are supported on a fan pedestal  20  which is securely attached to the foundation  12  in order to withstand the weight and the torque of the fan, and which encloses the electrical supply for the fan. In the lower portion  14 , the fan draws air from the large open chamber  18  and blows the air upward against the downward travel of water through the cooling system mounted in the upper portion  16 . Water is taken from the above-ground water basin  40  and is pumped into the nozzle array  53  that sprays water over the porous fill media  52  through which the water droplets travel downward at a pace that is slowed both by the fill media and the counter-flow of air, which prolongs the time available for evaporative cooling. An optional drift eliminator  54  mounted above the nozzle array  53  catches sprays and mists of water and retains them in the cooling system. Finally a water collector  51  that allows the flow of cooling air from below catches and channels the cooled water along its slight slope downward toward and into the water basin  40  from whence the water had come, completing one of the two loops of the system&#39;s operation. 
         [0049]    The purpose for cooling the water in the basin  40  is to use that cooled water in one or more heat exchangers that are components of HVAC systems or cooling systems for industrial processes. In the second loop of the system&#39;s operation, cooled water is pumped from the basin  40  to the target HVAC or cooling system or systems where it undergoes a heat exchange, and is pumped back into the basin  40  for another iteration of the two loops. 
         [0050]    The proper functioning of a cooling tower is critical to the functioning of HVAC systems and other cooling systems. If a cooling tower fails, it must be repaired or replaced. If a cooling tower is under-performing, or is under-specified in light of possibly unforeseen increased needs, it must be either replaced with or supplemented with another cooling tower. And such replacement or supplementation is likely to be needed immediately, where the efficient functioning of an enterprise is being hampered by a broken or under-performing cooling tower. The several months&#39; long construction times of present cooling towers are costly to the enterprises needing new cooling towers. 
         [0051]    The cooling-tower structure of the present invention is able to be constructed very quickly, in a matter of only a few days, for several reasons: 
         [0052]    The materials, known quantities of six different sizes and styles of standard CMU blocks are universally available at small cost, are available on pallets of manageable size and weight that can be moved with a standard forklift, and can be quickly secured and transported to any job site. The only other materials, rebar and sacks of cement, mortar, or grout, are equally as easily available. There is no waiting period for anything to be pre-fabricated or to be secured and transported from a remote location. 
         [0053]    The construction materials can be delivered to the job site—which might be the roof of a tall building—without the delays of arranging special shipments from far away, without arranging and waiting for special equipment such as cranes, and then waiting for permission to block streets with such equipment, and without arranging for the delivery and transfer of mixed concrete for on-site pouring to job sites that are not directly accessible to cement-mixer trucks. 
         [0054]    The construction work can be performed by any block mason of average competence and experience, using standard methods. Therefore there is a greater chance that such a block mason will be available no matter the locale or the timing of the construction. Also, the construction work can proceed more quickly by adding more block masons, up to a point, and by adding additional shifts of block masons. 
         [0055]    The construction work can proceed continuously to completion without waiting for any curing, drying, or setting up, or waiting for any special personnel or any special tool or material to arrive on site. 
         [0056]    The cooling-tower structure that results from the very quick construction time of only a few days, even in difficult locations, is very sturdy, long-lasting, and inherently two-hour fire-rated. 
         [0057]    The cooling-tower structure of this invention should be constructed on a suitable foundation, where the suitability will be determined by the specific construction site and conditions, which might range from a reinforced-concrete rooftop to a swampy spot of unused ground.  FIG. 10  illustrates a foundation for the preferred embodiment of  FIG. 9 , and  FIG. 11  illustrates a foundation for the smaller alternate embodiment of  FIG. 11 . In addition to whatever reinforcement and other requirements might be necessary for a particular foundation on a particular site, the foundation  12  should be of a size matching the footprint of the intended cooling-tower structure, which is 30 feet by 26 feet for the preferred embodiment here. Vertical reinforcement bars  90  or rebar should be embedded in the foundation  12  and attached to any horizontal reinforcement within the foundation. The placement of these vertical reinforcement rods is at the corners of the square tower structure under the corner columns  32 ,  34 , plus the outer corners of the water basin  40 , plus the eventual location of the fan pedestal  20 , which is at the center of the square formed by the upper portion  16  of the cooling tower, disregarding the water basin  40 . 
         [0058]    The length of the vertical reinforcement bars  90  embedded in the foundation  12  does not have to extend the full height of the cooling tower, and the length is not critical because additional reinforcement bars can be placed in upper courses, as is standard and known in the art. 
         [0059]    The secure attachment of the fan pedestal to the foundation is important because of the weight and the torque generated by the fan  22  in operation. 
         [0060]    Additionally, electrical conduit  95  for electric power to the fan may be incorporated in the foundation and terminated under the location of the fan pedestal  20 , although such electric power can also be run through surface-mounted conduit or by other conforming means. 
         [0061]    Turning now to the invention in more detail, numeral  10  designates the water cooling tower according to the present invention. It should be noted that the water cooling tower is only one example of the structure that can be constructed using the apparatus and method of the present invention. The cooling tower  10  comprises a hollow structure having a foundation  12 , a lower portion  14  supported by the foundation  12 , and an upper portion  16  supported by the lower portion  14 . The exemplary embodiment described herein is of a water cooling tower of counterflow design, where the air flow is directly opposite to the water flow. Air flow first enters an open area beneath the fill media, and is then drawn up vertically. The water is sprayed through pressurized nozzles near the top of the tower, and then flows downward through the fill, opposite to the air flow. 
         [0062]    The lower portion  14  defines an open chamber  18 , where a fan pedestal  20  is mounted. A motorized fan  22  is mounted on top of the fan pedestal  20 , with the fan and motor being protected by a fan shroud  24 . The fan shroud is supported by freestanding rear corner columns  32  and mid corner columns  34  incorporated into the above-ground water basin  40 . A lateral bonding beam  30  separates the lower portion  14  from the upper portion  16 , the lateral bonding beam  30  resting on the four columns of the lower portion  14 . 
         [0063]    A water collector assembly  51  is positioned in the upper portion  16  above the lateral beam  30 . The water collector assembly can be a series of troughs or one large trough configured to direct collected water away from the upper portion  16 . The water collector unit  51  is mounted at an angle to direct water by gravity into a basin  40  located above ground on the foundation  12 . An angle of approximately 2 degrees, or a 4-inch drop over a 24-foot span is sufficient. In an embodiment, the proper mounting angle is created by a spacer  93  shown in  FIG. 9  that provides a 4-inch rise and that may be made of various material, including concrete or steel, and may be incorporated into the construction of the cooling-tower structure, or into the installation of the cooling system into the tower structure, or may built into the water collector  51  itself. 
         [0064]    Pumps, known in the art, are used to circulate water through the cooling tower and from the cooling tower to the HVAC or cooling system or systems served by the cooling tower. Waterproofed piping and connections, also known in the art, can be placed through holes made in the cooling-tower structure and the water basin at the appropriate locations. 
         [0065]    The upper portion  16  defines an open space where the fill media  52  is deposited. 
         [0066]    Water is pumped from the basin  40  and sprayed through the nozzle assembly  53  and passes through the fill media before flowing into the water collector unit  51 . 
         [0067]    The corner columns  32 ,  34  are constructed from CMU blocks of 16-inch and 8-inch lengths, in alternating courses, as shown, using construction methods of reinforcement and filling with concrete, mortar, or grout known to block masons of normal skill and competence. Each column provides 40 square inches, in cross section, of support, and each is secured in 5 places to the foundation  12  through the vertical reinforcement bars  90 . 
         [0068]    Because the CMU blocks themselves define the structural frame for the concrete, there is no need to wait for the concrete to set in a lower course or layer before placing additional courses on top, and construction can proceed without delay. 
         [0069]    After the corner columns  32 ,  34  are constructed from standard 16-inch and 8-inch CMUs  71 ,  72  the lateral bond beams  30  can be constructed from deep lintel CMUs  74 . A temporary support structure  79  can be used to hold the lateral bond beams  30  in place until the concrete  78 , mortar, or grout securing the reinforcement bars  90  sets up. In the alternative, the deep lintel CMUs  74  comprising the bond beams  30  can be assembled on an adjacent flat surface and later hoisted into place. Because the exact materials and dimensions of the bond beams  30  are known in advance, they can be assembled in advance of the time they are needed to be put in place. 
         [0070]    The bond beam  30  is constructed from deep lintel CMUs  74  securely bonded together by reinforcement bar  90  and concrete  78 , mortar, or grout, and effectively forming a lintel. Where a deep lintel CMU  74  sits over another CMU, such as at a corner, it can be vertically secured by placing a reinforcement bar  90  through a notch  77  in the face of CMU that is mounted downward. A vertical reinforcement bar is positioned transversely to the horizontal reinforcement bar or bars. The vertical reinforcement member  90  extends through the notch  77 . 
         [0071]    The preferred materials of construction are CMU concrete blocks with a waterproof coating applied to the inside walls of the cell and basin to prevent water seeping through the blocks. 
         [0072]    The structure of the present invention requires only an above-ground foundation with only a single conduit in the slab for power and controls for the fan. Once the foundation is completed, the blocks will arrive by truck and the block masons can immediately begin installing blocks. A single cell tower can be erected in 3 working days. Multiple cells can be staged with additional block masons and can go up just as quickly. No special equipment (i.e. cranes, forklifts, etc.) are required to erect the tower. A crane will be required to set the water collectors inside the erected tower. The lifts required to install the collectors are less than 1,000 lbs per lift so the size of the crane required is minimal. Everything else will be installed by hand. The total time required to install a working cell is less than two weeks. 
         [0073]    Many changes and modifications can be made in the present invention without departing from the spirit thereof. We, therefore pray that our rights to the present invention be limited only by the scope of the appended claims.