Abstract:
A water-cooling ozone generation tube assembly includes a twin-tube type ozone generation tube module and a tube holder. The twin-tube type ozone generation tube module contains an inner tube and an outer tube. The ozone generation tube assembly of the present invention is water cooled; both the inner tube and the outer tube of the tube module are cooled by water so as to improve the cooling effect and further increase the ozone generation throughput. The ozone generation tube assembly can be configured to include more than one ozone generation tube module when a large amount of ozone is to be produced.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to a twin-tube type, water-cooling ozone generation tube assembly. More particularly, the invention relates to an ozone generation tube assembly including multiple ozone generation tube modules, wherein each tube module has an inner tube and an outer tube, and both the inner and outer tubes are cooled by water. 
       BACKGROUND OF THE INVENTION 
       [0002]    Ozone is usually applied to treat the water to be used in semiconductor industries, aquatic product industries, swimming pools, households, etc. In a typical process of ozone production, oxygen-containing gas is guided through a high voltage discharge zone in an ozone generation tube, across which a high voltage is applied. The oxygen will be ionized while passing through the ozone generation tube. 
         [0003]    U.S. Pat. No. 4,101,783 discloses similar features of producing ozone in an ozone generation tube. As shown in  FIG. 1 , the ozone generator comprises several twin-walled upright glass tubes  1 . Each tube  1  has an inner wall  1   a,  an outer wall  1   b,  an inlet  5  which admits air (or another oxygen-containing gas) into an annular chamber  3  between the walls  1   a,    1   b,  and an outlet  6  which serves to evacuate enriched gas from the chamber  3 . A first electrode  12  overlies the median portion of the inner side of the inner wall  1   a,  and a second electrode  8  overlies the median portion of the outer side of the outer wall  1   b  opposite the electrode  12 . When the generator is operated, a high voltage is applied across the electrodes  12 ,  8 , which causes an electric arc between the electrodes and generates ozone. 
         [0004]    In the discharge reaction, a large amount of heat energy is generated. The ozone generation tube, which provides the chamber for the discharge reaction to take place in, has to endure the heat thus generated. In many circumstances, the production rate of ozone should be large enough to meet the practical need. Thus, more heat would be generated in the ozone generation tube. The heat often causes the tube to rise to a very high temperature, which may damage the tube or reduce the lifespan of the tube. Heat reduction is thus a significant issue for an ozone generation system used for a higher rate of ozone generation. 
         [0005]    Water cooling is usually used to reduce the heat produced in the ozone generation tube in the ozone generation industry. However, the state of the art only relates to cooling the outer tube of the ozone generator. It is known that the temperature in the inner tube is also very high in the discharge process. Accordingly, it is an object of the present invention to improve the cooling effect of the inner ozone generation tube by cooling it where temperature is high enough to damage the tube. 
         [0006]    It is also an object of the present invention to provide means to produce a higher ozone generation rate having a sufficient cooling effect. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention provides a twin-tube ozone generation tube, where both the inner tube and the outer tube are water cooled to effectively reduce the heat generated therein. 
         [0008]    To achieve the object of effectively cooling the ozone generation tube, the ozone generation system of the present invention further contains a tube holder, which not only holds the ozone generation tube in place but also provides a chamber so that cooling water may pass through and thereby carry away the heat transferred from the tube to the tube holder. 
         [0009]    To achieve the object of providing a higher ozone production rate, the ozone generation tubes according to the present invention can be assembled together by stacking the tube holders in a desired manner. 
         [0010]    The specific measures for achieving the objects of the present invention will become apparent to those skilled in the art by making reference to the drawings of the present invention and the following detailed descriptions of the preferred embodiment. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0011]      FIG. 1  is a perspective view of an ozone generation tube assembly of the present invention; 
           [0012]      FIG. 2  is a cross-sectional view taken along line  2 - 2  in  FIG. 3 ; 
           [0013]      FIG. 3  is a cross-sectional view taken along line  3 - 3  in  FIG. 2 ; 
           [0014]      FIG. 4  shows the interior of the ozone generation tube assembly; 
           [0015]      FIG. 5  shows the state in which the ozone generation tube assembly is constituted by multiple tube modules; and 
           [0016]      FIG. 6  shows the end view of the ozone generation tube assembly not shown in  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    Referring to  FIG. 1 , the ozone generation tube assembly  100  comprises a twin-tube type ozone generation tube module  80  and a tube holder  70 . The two ends of the tube assembly  100  are sealed as shown in  FIG. 2 . 
         [0018]    The tube module  80  comprises an aluminum tube  10 , a tubular electrode  30 , an inner quartz tube  50 , and an outer quartz tube  60 . The aluminum tube  10 , which is the innermost ring of the tube module  80 , has a water inlet  12  and a water outlet  14 . The aluminum tube  10  is enclosed in the tubular electrode  30  and an annular gap is formed between the aluminum tube  10  and the tubular electrode  30 . The annular gap is filled with an insulation layer  20  so that the aluminum tube  10  and the tubular electrode  30  are kept electrically insulated from each other. The insulation layer  20  also serves to fix the aluminum tube  10  in the tubular electrode  30 . The insulation layer  20  may be made of materials selected from rubber. The inner quartz tube  50  is arranged to enclose the tubular electrode  30  and the outer quartz tube  60  is arranged to enclose the inner quartz tube  50  so that an annular space  52  is formed. The annular space  52  is closed at both its ends by sealing the ends of the inner quartz tube  50  and the outer quartz tube  60 . A gas inlet  54  is provided at one end of the outer quartz tube  60  and a gas outlet  56  is provided at the other end of the outer quartz tube  60 . 
         [0019]    A tube holder  70  is provided to enclose the tube module  80 . The tube holder  70  has at least one water inlet  72  and at least one water outlet  74 . 
         [0020]    During operation, a high voltage of 30,000V to 40,000V is applied across the tubular electrode  30  and the tube holder  70 , and the tubular electrode  30  serves as the anode and the tube holder  70  serves as the cathode or ground electrode. The tubular electrode  30  is in contact with the inner side of the inner quartz tube  50 . To increase conductivity between inner quartz tube  50  and the tubular electrode  30 , the inner side of the inner quartz tube  50  is plated with a metal coating  40 . Due to the high voltage applied across the two quartz tubes  50 ,  60 , a high heat energy, and thus a high temperature, would be produced in the quartz tubes. 
         [0021]    It is known that metal coating may not endure high temperature. As shown in the figures, cooling water is supplied via the water inlet  12 . Thus, the heat generated in the inner quartz tube  50  can be carried away by the cooling water flowing out of the tube  50  via water outlet  14 . The surface of the tube  50  will thus remain at a relatively lower temperature so that the metal coating thereon will not be damaged. The coating can be chosen from a variety of materials regardless of their melting points, and gold, having a lower melting point but good conductivity and a good corrosion-resistant property, is preferred in this condition. 
         [0022]    Since the aluminum tube  10  should be kept from direct contact with the cooling water therein, an anodic treatment on the surface of the aluminum tube  10  is preferable. 
         [0023]    In a preferred embodiment, the tube holder  70 , as shown in the figures, is composed of two halves  70 ′,  70 ″. The tube holders  70  are configured so that they can be easily connected to each other. Multiple tube modules are necessary in order to produce large amount of ozone.  FIG. 5  shows the state in which the tube modules fitted in the tube holders are stacked. With multiple tube modules being operated simultaneously, the capacity to generate ozone can be raised. 
         [0024]    For the purpose of easy assembling, the tube holder  70  can be formed by two halves  70 ′,  70 ″. For economic purposes, the two halves  70 ′,  70 ″ can be made identical. 
         [0025]    As shown in  FIG. 3 , the tube holders  70 ′ and  70 ″ each comprise a water inlet  72  and a water outlet  74 . The tube holder  70  is arranged so that it is in direct contact with the tube module  80 , to be more specific, the external surface of the outer quartz tube  60 . The side of the tube  70 , which contacts the tube module  80 , is preferably made into a cylindrical surface so as to better fit with the surface of the tube module  80 . Similar to the manner in which the heat generated in the inner quartz tube  50  is carried away by the cooling water passing therein, the heat generated in the outer quartz tube  60  is transferred to the tube holder  70  and carried away by the cooling water passing through the tube holder  70 . 
         [0026]    As shown in  FIGS. 1 and 3 , a preferred embodiment of one half of the tube holder  70  has an upper and a lower horizontal surface  73 ,  73 ′, a left and a right vertical surface  75 ,  75 ′, and thus forms four corners. Two semi-cylindrical surfaces  76  are symmetrically formed on the upper horizontal surface  73  and the lower horizontal surface  73 ′. A first pair of channels  78  is formed symmetrically on the left vertical surface  75  near the upper left corner and the lower left corner, respectively. A second pair of channels  78 ′ is formed symmetrically on the right vertical surface  75 ′ near the upper right corner and the lower right corner, respectively. The second pair of channels  78 ′ is symmetrical with the first pair of channels  78 . Referring to  FIG. 3 , each of the channels has an inward width W 1  and an outward width W 2 , and the inward width W 1  is greater than the outward width W 2 . 
         [0027]    As shown in  FIGS. 1 and 5 , a vertical clamp  90  is made to fit the channels formed by the lower channel and the upper channel of two vertically adjacent tube holder halves  70 ′,  70 ″ and is used to connect tube holder halves  70 ′,  70 ″ together. 
         [0028]      FIG. 5  shows a plurality of tube holder halves connected together with tube modules  80  contained therein. In  FIGS. 5 and 6 , the tube holders stacked in a vertical manner are connected by vertical clamps  90  and form two separate stacks. The two stacks of tube holders are further connected by a horizontal clamp  92  on the top of the stacks and another one on the bottom of the stacks. The horizontal clamp  92  is made to fit the channels formed by the uppermost two horizontally adjacent tube holders. Another horizontal clamp  92  fits the channels formed by the lower channels of the lowest two horizontally adjacent tube holders. 
         [0029]    The preferred material selected to make the tube holder  70  is aluminum since the cost of aluminum is low, and aluminum has a good heat-transfer property and electrical conductivity. In addition, aluminum can be easily formed into the desired shape by extrusion processes, and the material wasted in machining can be avoided. 
         [0030]    The invention may also be implemented in other specific modes without departing from the spirit of the invention. Thus, the above-mentioned embodiments shall be regarded as explanatory but not restrictive. All changes that are consistent with the meaning and range of the claims and the equivalents shall fall within the scope claimed by the invention.