Patent Publication Number: US-2010122912-A1

Title: Water treatment device

Description:
TECHNICAL FIELD 
     Exemplary embodiments relate to a water treatment device. More particularly, exemplary embodiments relate to a mechanical water treatment device employing electrical current to remove impurities from water. 
     BACKGROUND AND SUMMARY OF THE INVENTION 
     Large cooling systems and other systems employing recirculating water may require water treatment. Water treatment may be required to prevent scale build-up, fouling from settlement solids, microbiological growth, and system corrosion. Calcium carbonate scale is a significant problem for recirculating water systems as it precipitates on heat exchange surfaces. This build-up of scale causes the water recirculating system to work harder and expend more energy to accomplish the same level of cooling. This in turn increases the cost to operate the recirculating water system. 
     Corrosion is another problem that must be overcome in the operation of a recirculating water system. Corrosion is of particular concern with respect to ferrous metal components in the recirculating water system. Corrosion may dramatically shorten the life span of key components common to most recirculating water systems. One of the primary culprits in the corrosion found in recirculating water systems is calcium ions. 
     Microbiological growth is another major concern in the operation of recirculating water systems. Cooling towers used in recirculating water systems are a natural place for algae and bacteria to grow and cause serious problems if microbiological controls are not in place. Microbes may grow within the cooling tower and present serious corrosion issues and other potential issues, if not controlled. Along with microbiological growth, mud may also be a concern as cycles of concentration increase in the cooling towers. The combination of microbiological growth and mud may lead to airborne contaminants. 
     Fouling from settleable deposits is another concern in the operation of recirculating water systems. As the solids settle they may reduce the flow through components of the recirculating water system. In addition, underdeposit corrosion may be caused by the settlement of solids. 
     Traditionally, to combat the problems associated with recirculating water systems chemical systems have been employed. This form of water treatment requires the addition of chemicals to the water in an attempt to prevent scaling, microbiological growth, and system corrosion. Although the addition of chemicals into the water may help alleviate some of the problems associated with recirculating water systems problems may still remain. In addition, chemical water treatment is costly, may be harmful to the environment, and requires significant safety measures. As such, there is a need to provide reliable, cost effective water treatment without the need for expensive and potentially dangerous chemicals. 
     The mechanical water treatment device utilizing electrical current disclosed herein, may prevent scaling, corrosion, microbiological growth, and fouling from settleable solids without the need for chemical additives. Water circulating through the recirculating water system is passed through the water treatment device where it is exposed to an electrical current between an anode and a rotating cathode. The current causes the water to hydrolyze into hydroxide ions that accumulate at the cathode and hydrogen ions that accumulate at the anode. The hydroxide ions at the cathode cause the pH to rise at the surface. Bicarbonate ions within the area of higher pH are oxidized to carbonate ions that in turn react with calcium ions to form calcium carbonate. Hydrogen ions at the anode readily accept electrons from chloride ions causing the chloride ions to combine to form chlorine. 
     As the major cause of scaling, calcium carbonate is a problem for recirculating water systems. The water treatment device controls scale by precipitating calcium carbonate and removing it from the system thereby maintaining the concentration of calcium and carbonate ions in the system below the threshold solubility of calcium carbonate. 
     The water treatment device may prevent corrosion by removing low solubility calcium ions. With low solubility calcium removed, significantly more evaporation per unit of make-up volume may occur since the remaining ions will remain soluble. The corrosion rate of ferrous metals is reduced as total dissolved solids and pH of the water in the system rise. In addition, as the calcium carbonate is precipitated out of solution, other dissolved solids including magnesium and bicarbonate increase. The increase in magnesium provides natural corrosion inhibition and the increase in alkalinity causes the pH to climb which further reduces the corrosion on steel and other ferrous metals. 
     The growth of microbiologicals is also controlled by the water treatment device. As stated above, the hydrogen ions at the anode readily accept electrons from the chloride ions causing the chloride ions to combine into chlorine. The chlorine created by the water treatment device oxidizes microbes. The water treatment device also exposes the microbes to extremely high and low pH and permits elevated concentrations of total dissolved solids that reduce the survivorship of microbes entering the system. The water treatment device&#39;s use of electrical current further disrupts the cellular metabolism and replication of harmful microbiologicals. 
     To prevent fouling from settleable solids, the water treatment device may employ a centrifugal separator. This separator not only removes calcium carbonate, but also other suspended solids circulating in the cooling system. The water treatment device may remove virtually all circulating solids larger than about 10 microns. 
     The water treatment device also offers several advantages over the use of chemical water treatment. The water treatment device eliminates the need to use, store, and handle chemicals including sulfuric acids and toxic biocides. The water treatment device eliminates chemical discharge to the environment and reduces the water usage. Some exemplary embodiments of the water treatment device are fully automated. Exemplary embodiments of the water treatment device may include a tank having a fluid inlet and a fluid outlet. The tank may contain an anode and a cathode. As water enters the tank it is subjected to an electrical current flow through between the anode and cathode. Undesirable minerals such as calcium carbonate begin to precipitate out of solution onto the cathode. A scraping means may be attached to the interior of the tank. The scraping means may extend from the tank inward toward the cathode so as to define a gap between the scraping means and the cathode. An electrical motor may be provided in mechanical communication with the cathode providing rotational motion to the cathode. As the cathode is rotated excess mineral deposits are scraped off by the scraping means as the cathode rotates inside the tank. 
     In addition to the novel features and advantages mentioned above, other objects and advantages of the present invention will be readily apparent from the following descriptions of the drawings and exemplary embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A better understanding of the disclosed embodiments will be obtained from a reading of the following detailed description and the accompanying drawings wherein identical reference characters refer to identical parts in which: 
         FIG. 1  is a perspective view of an exemplary embodiment of the water treatment device. 
         FIG. 2  is an exploded view of an exemplary embodiment of the water treatment device. 
         FIG. 3  is a cross-sectional view of an exemplary embodiment of the water treatment device having no mineral deposit on the cathode. 
         FIG. 4  is a cross-sectional view of an exemplary embodiment of the water treatment device having a layer of mineral deposits on the cathode. 
         FIG. 5  is a diagram illustrating an exemplary embodiment of the water treatment device. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT(S) 
     Exemplary embodiments are directed toward a water treatment device and a system and method of water treatment utilizing the water treatment device. Exemplary embodiments may be used with recirculating water systems or any other system where there is a need for water treatment. 
       FIG. 1  illustrates an exemplary embodiment of the water treatment device  10 . The water treatment device  10  may have a tank  12 . The tank  12  may be constructed of a plastic material. The use of a plastic material may prevent the corrosion of the interior and exterior of the tank  12 . In other embodiments, the tank  12  may be constructed from a metallic material. The metallic material may be coated to prevent corrosion with an epoxy or other suitable material. The tank  12  may have a solid unitary configuration. In other exemplary embodiment, the tank  12  may have an upper and lower portion joined together with a water tight sealing means. The sealing means may be an adhesive, sealant, or mechanical fasteners providing a water tight seal. The use of a multipart tank  12  may allow easy access to the components contained within the tank  12 . The tank  12  may have a substantially cylindrical shape, having an increased diameter through the middle portion. This may increase the efficiency of the water treatment device  10 . 
     The tank  12  may have a fluid inlet  14  located toward the bottom of the tank  12 . The fluid inlet  14  allows water to enter the tank  12 . A fluid outlet  16  may also be located on the tank  12 . In the embodiment shown in  FIG. 1  the fluid outlet  16  may be located below the fluid inlet  14 . The fluid outlet  16  allows treated water to exit the water treatment device  10  and reenter the system. The fluid outlet  16  may be located on the tank  12  opposite the fluid inlet  14 , or at any other location on the tank  12 . The fluid inlet and fluid outlets  14  and  16  may be located at any point around the circumference of the tank  12 . The water treatment device  10  may also have a clean out  24  located on the tank  12 . The clean out  24  may facilitate removal of scaling material from the tank  12 . The clean out  24  may be used during water treatment to flush any excess scaling material from the system. 
     To maintain an upright position a stand  18  may be positioned at the bottom of the tank  12 . The stand  18  may allow the water treatment device  10  to remain free standing without the need for further support. This may aid in decreasing the space necessary to place and operate the water treatment device  10 . 
     A cap  20  may be provided along the top portion of the tank  12 . The cap  20  may be joined to the tank  12  by a water tight means, such as adhesives, sealants, or mechanical device providing a water tight seal. A motor  22  may be affixed to the cap  20 . The motor  22  may provide the means necessary for movement of the components within the tank  12 . To control the components within the tank  12 , the motor  22  interfaces with the components within the tank  12 . The motor  22  may be any electrical powered motor capable of providing rotational motion to the cathode  30  (as shown in  FIG. 2 ). The cathode  30  may rotate about its longitudinal axis. In other exemplary embodiments, the tank  12  may be formed to create a cap portion, eliminating the need for a separate cap  20 . This embodiment would eliminate the need for additional water tight seals. 
     As shown in  FIG. 2 , the motor  22  is connected to the cathode  30  through the cap  20 . The motor  22  is fixed to the cap  20  in a water tight manner. The motor  22  provides rotational motion to the cathode  30 . The cathode  30  is positioned so as to run down the center of the tank  12 . In other exemplary embodiments, the cathode  30  may be positioned at any location within the tank  12 . In some embodiments, the cathode  30  may have a cylindrical shape. The cathode  30  may be rotatably fixed to the bottom portion of the tank  12  to ensure the cathode  30  maintains a vertical configuration during operation. An anode  32  is also placed in the tank  12 . The anode  32  may be affixed to a side of the tank  12 . The anode  32  may also be in communication with a control unit  26  affixed to the exterior of the tank  12 . The control unit  26  provides constant current to the water treatment device  10 . It should be understood by those skilled in the art that any number of anodes  32  may be used and the positioning may changed based on the system requirements. 
     As water enters the tank  12 , it is exposed to electrical current between the cathode  30  and anode  32 . The current causes the water to hydrolyze into hydroxide ions that accumulate at the cathode  30  and hydrogen ions that accumulate at the anode  32 . The hydroxide ions at the cathode  30  cause the pH to rise at that surface. Bicarbonate ions within the area of higher pH are oxidized to carbonate ions that in turn react with calcium ions to form calcium carbonate. The calcium carbonate may then precipitate out of solution onto the cathode  30 . This removal of calcium carbonate from the water decreases scaling in the system. Although described using the example of calcium carbonate removal, one skill in the art would understand that any metal or mineral forming scale may precipitate out of solution onto the cathode  30 . To remove portions of the scale from the system a scraping means  34  is affixed to the side of the tank  12 . The scraping means  34  may run the length of the cathode  30  and is positioned so as to form a gap  40  (as shown in  FIG. 3 ) between the scraping means  34  and the cathode  30 . In some exemplary embodiments, the gap  40  defined by the scraping means  34  and the cathode  30  may be in a range between about 1/16 of an inch to about ¼ of an inch. In other exemplary embodiments, the gap  40  may be in a range between about ⅛ of an inch to about ¼ of an inch. In still other exemplary embodiments, the gap  40  may be about ⅛ of an inch. 
     During operation of the water treatment device  10 , scale builds up on the cathode  30  filling the gap  40  between the scraping means  34 . Once the depth of the scale is greater than the gap  40  between the scraping means  34  and the cathode  30 , the scale comes into contact with the scraping means  34  and is removed from the cathode  30 . This scale removal process is possible because of the rotational motion of the cathode  30 . As the cathode  30  rotates, the stationary scraping means  34  removes the excess scale  42 . A layer of scale  38  (as shown in  FIG. 4 ) substantially equal to the gap  40  between the scraping means  34  and the cathode  30  remains on the cathode  30  preventing corrosion of the cathode  30 . The scraping means  34  may be constructed of durable material able to withstand removing the excess scale  42 ; such materials may include, but are not limited to metals and hard plastics or resins, that may be shaped in the form of a chisel or a knife blade, among other suitable configurations. 
     This is further illustrated in  FIG. 3 and 4 , which is a cross section of water treatment device at line AA, as seen in  FIG. 1 .  FIG. 3  illustrates the cathode  30  having no mineral deposits thereon.  FIG. 4  illustrates the cathode  30  during operation of the water treatment device  10  having scaling deposits thereon. A stationary scraping means  34  extends from the tank  12  inward toward the cathode  30  without contacting the cathode  30  so as to define a gap  40 . 
     During operation of the water treatment device  10 , a layer of scale  38  and other undesirable minerals form on the cathode  30 . A stationary scraping means  34  extends from the tank  12  inward toward the cathode  30  without contacting the cathode  30  so as to define a gap  40  (shown in  FIG. 3 ) between the distal end of the scraping means  34  and the cathode  30 . As the water treatment device  10  continues to operate, the layer of scale  38  increases in depth. Once the depth of the scale layer  38  is greater than the gap  40  between the scraping means  34  and the cathode  30 , the excess scale  42  is removed from the layer of scale  38 . As the cathode  30  rotates the excess scale  42  is scraped off by the stationary scraping means  34 . The remaining layer of scale  38  may have a depth substantially equal to the gap  40  between the scraping means  34  and the cathode  30 . After the removal of the excess scale  42  from the cathode  30 , the excess falls to the bottom of the tank to be filtered out of the system. 
     By providing a rotating cathode  30  and a stationary scraping means  34  the water treatment device  10  is able to continuously remove excess precipitated scale forming material from the water in the system, without the need to stop treatment to remove excess particulates. This represents a significant advantage over other water treatment systems. 
     In other exemplary embodiments of the water treatment device  10 , the motor  22  may be in connected to the scraping means  34 , and the cathode  30  may be stationary inside the tank  12 . In this configuration, the scraping means  34  may rotate around the cathode  30  removing excess scale deposits  42 . In still other exemplary embodiments, both the scraping means  34  and the cathode  30  may be in communication with the motor  22 . In this manner, the cathode  30  and scraping means  34  may rotate in opposing directions or in the same direction at differing speeds to facilitate removal of the excess scaling material  42 . The different embodiments described above all allow the water treatment device  10  to remove excess mineral deposits without the need to stop treatment of the water. 
     Once the excess scale  42  is removed from the cathode  30  it may be filtered out of the system. As the water to be treated passes through the water treatment device  10 , for example, at about 125 gallons per minute, the rotation of the components in the tank  12 , the shape of the tank  12 , and the force of the water drive the removed excess scaling material  42  to the bottom of the tank  12 . The rotation of the cathode  30  or the scraping means  34  and the shape of the tank direct the incoming water into a vortex forcing the removed excess scaling material  42  to the bottom of the tank  12 . In this manner the water treatment device  10 , does not require the need for a media filter to remove the excess scaling material  42  from the system. Although, it should be understood that a media filter may still be used with the water treatment device  10 . The clean out  24  may be employed to remove the excess scaling material  42  after a sufficient amount has accumulated at the bottom of the tank  12 . 
     The water treatment device  10  may be used in-line with any recirculating water system. An example of this may be seen in  FIG. 5 . As shown in  FIG. 5 , the water treatment device  10  may be used to constantly treat water in a holding tank  50 . The water flows from the holding tank  50  through the water treatment device  10  and the treated water is carried back to the holding tank  50 . Although  FIG. 5  illustrates a single water treatment device  10  one skilled in the art would appreciate the ability to arrange multiple water treatment devices  10  in series or parallel depending on the treatment needs of the system. 
     Any exemplary embodiment may include any of the optional or preferred features of the other embodiments. The exemplary embodiments herein disclosed are not intended to be exhaustive or to unnecessarily limit the scope of the invention. The exemplary embodiments were chosen and described in order to explain the principles of the claimed invention so that others skilled in the art will realize that many variations and modifications may be made to affect the described invention. Many of those variations and modifications will provide the same result and fall within the spirit of the claimed invention. It is the intention, therefore, to limit the invention only as indicated by the scope of the claims.