Patent Publication Number: US-11020715-B2

Title: Gas-liquid dissolving apparatus

Description:
TECHNICAL FIELD 
     The technical field generally relates to a gas-liquid dissolving apparatus, in particularly, to a sealed tank forming a plurality of mixing chambers to increase the total contact area of the liquid and the gas, prolong the bubble residence time, and improve the dissolution efficiency. 
     BACKGROUND 
     The current apparatus for dissolving a gas a liquid is usually assisted by a diffuser or a Venturi tube. As shown in  FIG. 1A , the apparatus for dissolving a gas in a liquid using a diffuser includes a high-pressure gas supply bottle  11 , a tank  12 , and a diffuser  13  installed in the tank  12 . The tank  12  is provided with a liquid inflow pipe  121 , a liquid outflow pipe  122 , and an exhaust pipe  123  for allowing liquid to enter the tank to output a gas solution with high concentration of the gas. The high-pressure gas supply bottle  11  is connected to a gas pipe  14  to the diffuser  13 . The diffuser  13  can generate a large amount of very fine bubbles in the incoming gas, and use fine bubbles to increase the gas-liquid contact area during the rising time of the bubble to increase the efficiency of the gas dissolved in the liquid and obtain a high concentration gas solution. In addition, when the tank  12  has too much gas or the pressure is too large, the gas can be exhausted through the exhaust pipe  123 . However, this apparatus has some disadvantages when used:
     1. The time that the bubble stays in the liquid is too short, resulting in insufficient dissolution. If the residence time is to be extended, the longitudinal height of the tank  12  must be lengthened, which causes the tank volume to be too large and takes up space.   2. The total area of gas-liquid contact cannot be greatly increased, resulting in insufficient dissolution.   

       FIG. 1B  is an apparatus for dissolving a gas in a liquid using a Venturi tube. The Venturi tube  21  includes a liquid inflow pipe  211 , a liquid outflow pipe  212 , and a gas inlet pipe  213 . The liquid inflow pipe  212  is further connected to an infusion pipe  22  and a pump  23  to allow liquid to be sent into the Venturi tube  21 . The gas to be dissolved in the liquid is mixed with the liquid through the gas inlet pipe  213  to be dissolved. The principle of the device is: using high-pressure water to flow through the constricted section (called choke) of the inner pipe to generate a high-speed jet, causing a negative pressure to suck the gas into the choke, mixed with the high-speed jet liquid for dissolution, and the outflow contains a dissolved gas solution. However, the disadvantages of this structure include that the amount of added gas is controlled by the liquid flow rate, which has a small adjustable range, the resulting bubbles are large, the contact area is relatively small, and the mixing efficiency is low. 
     SUMMARY 
     The object of the present invention provides a gas-liquid dissolving apparatus with high dissolving efficiency, mainly by stacking a plurality of membrane plates in a sealed tank to form a plurality of specific spaces for mixing gas and liquid, thereby increasing the total surface area of the gas and prolonging the bubble residence time. Under the conditions of increased contact area and prolonged time, the efficiency of dissolving the gas in the liquid is significantly improved. 
     To achieve the above object, the present invention provides a gas-liquid dissolving apparatus, comprising: a sealed tank, a gas jet tube and a plurality of membrane plates; the sealed tank being provided with a liquid-supply joint at top, and a gas inlet joint and an output joint at bottom; the gas jet tube being located inside the sealed tank, with a top end closed and a bottom portion connected to the gas inlet joint; the gas jet tube has a plurality of gas jet holes distributed on tube wall; the plurality of membrane plates being stacked around the periphery of the gas jet tube and fixed; each membrane plate having a ring shape, and being structured with an inner ring wall, a mixing chamber and an outer ring wall sequentially from the center; the mixing chamber having an opening facing downward, and the inner ring wall being thicker than the outer ring wall, so that a gap existing between the outer ring walls of two adjacent stacked membrane plates; the inner ring wall being axially provided with at least an axial passage, and provided at different radial positions with at least a radial passage and at least a gas passage respectively; the radial passage communicating with the axial passage and the mixing chamber; the gas passage corresponding to the gas jet holes and communicating with the mixing chamber. 
     During the operation of the gas-liquid dissolving apparatus of the present invention, the liquid is injected from the liquid-supply joint at the top of the sealed tank, and fills the plurality of mixing chambers and the entire sealed tank through the axial passage and the radial passage. The gas is injected from the gas inlet joint at the bottom of the sealed tank, and is ejected through a plurality of gas jet holes of the gas jet tube, and is guided through the gas passage to cause fine bubbles to fill the mixing chamber to prolong the bubble residence time. In addition, the up to 10 layers of membrane plates with mixing chambers greatly increase the total surface area of the fine bubbles in contact with the liquid, thereby increasing the gas-liquid dissolution rate and the amount of dissolution. 
     The plurality of the gas jet holes of the gas jet tube of the present invention are divided into a plurality of groups according to being located at different heights, and the plurality of the gas jet holes of the same group are distributed at an equal angular interval at the same height on the tube wall, a plurality of gas passages are radially disposed on the inner ring wall, and the plurality of gas jet holes of the same group correspond to the plurality of gas passages of the membrane plate. 
     Furthermore, the outer diameter of the membrane plate is smaller than the inner diameter of the sealed tank, and the center has a central hole. The central hole is matched to the shape and size of the gas jet tube. The plurality of the axial flow channels are connected to the central hole at equal angles. When the plurality of the membrane plates are stacked and sheathed to surround the outer periphery of the gas jet tube, the vertically adjacent axial passages serve as a passage for the liquid to flow. The radial passage and the gas passage are all concave passages with downward openings, and are distributed at an equal angular interval on the inner ring wall in an interleaved manner. The radial flow channel has greater width and depth than the gas passage, whereby fine bubbles ejected by the gas jet hole are distributed in the mixing chamber through the gas passage, and the liquid is ejected through the radial passage to generate a jet liquid flow to the mixing chamber. The jet liquid flow, in addition to further dispersing the bubbles to make the bubbles finer for increasing the contact area, also prevents the bubbles from stopping to flow and accumulating in the mixing chamber, thereby affecting the gas-liquid dissolution operation. 
     The foregoing will become better understood from a careful reading of a detailed description provided herein below with appropriate reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments can be understood in more detail by reading the subsequent detailed description in conjunction with the examples and references made to the accompanying drawings, wherein: 
         FIG. 1A  is an apparatus for dissolving gas in liquid by using diffuser; 
         FIG. 1B  is an apparatus for dissolving gas in liquid by using Venturi tuber; 
         FIG. 2  is a schematic view showing the gas-liquid dissolving apparatus of the present invention; 
         FIG. 3  is a schematic view showing the internal structure of the gas-liquid dissolving apparatus of the present invention; 
         FIG. 4  is a cross-sectional view of the gas-liquid dissolving apparatus of the present invention; 
         FIG. 5  is a schematic view after combining the gas jet tube and the membrane plates of the present invention; 
         FIG. 6  is an exploded view of the gas jet tube and the membrane plates of the present invention; 
         FIG. 7  is an enlarged bottom view of the membrane plate of the present invention; 
         FIG. 8  is the first enlarged schematic view of a partial longitudinal cross-section of the present invention, which is a longitudinal cross-sectional view of the position of the positioning post; 
         FIG. 9  is the second enlarged schematic view of a partial longitudinal cross-section of the present invention, which is a longitudinal cross-sectional view of the position of the radial passage; 
         FIG. 10  is the third enlarged schematic view of a partial longitudinal cross-section of the present invention, which is a longitudinal cross-sectional view of the position of the gas passage. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS 
     In the following detailed description, for purpose of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing. 
       FIG. 2 ,  FIG. 3  and  FIG. 4  show a schematic view, a internal structure view and a cross-sectional view of a gas-liquid dissolving apparatus of the present invention, respectively. The gas-liquid dissolving apparatus of the present invention includes a sealed tank, a jet tube  4  and a plurality of membrane plates  5 . The plurality of membrane plates  5  are placed in a stacked manner around the periphery of the jet tube  4  and are fixed inside the sealed tank  3 . 
     The sealed tank  3  is a long cylindrical container with closed surrounding wall, with a partition member  31  disposed inside. The partition member  31  partitions the inside of the sealed tank  30  into an upper space  32  and a lower space  33 . The jet tube  4  and the plurality of membrane plates  5  are located in the lower space  33 , where is the working area for main liquid-gas mixing and dissolving, and is also the design focus of the present invention, which will be described in detail later. 
     Although the partition member  31  is located at the middle of the sealed tank  3 , the partition member  31  does not completely block the passage of gas and liquid between both spaces. A gas guiding tube  311  is disposed at non-central area of the partition member  31 , and is located in the upper layer space  32  but still communicates with the lower layer space  33 . The gas guiding tube  311  has a gas outlet  312  located in the upper layer area of the upper layer space  32 . The partition member  31  is disposed with at least an axially penetrating first liquid flow passage  313  in central area. The first liquid flow passage  313  supplies liquid to the lower space  33 , or more precisely, the first liquid flow passage  313  supplies liquid to the central area of the plurality of membrane plates  5 , and then passes through the gap between the adjacent two membrane plates to fill the entire lower space  33 . In the present embodiment, the partition member  31  is coupled to the top end of the gas jet tube  4  and fixed by screwing. 
     The top of the sealed tank  3  is provided with a liquid supply joint  34  and a pressure relief joint  35 , and the two joints communicate with the upper space  32 . The liquid supply joint  34  is for connecting an external liquid supply tube to supply the liquid into the sealed tank  3  from top down. A liquid outlet tube  341  is further disposed inside the sealed tank  3  to connect to the liquid supply joint  34 . The liquid outlet  342  of the outlet tube  341  is close to the first liquid flow passage  313 . The pressure relief joint  35  is used to connect a tube for discharging excess gas or liquid at an appropriate timing to adjust the pressure in the sealed tank  3 . A gas inlet joint  36  and an output joint  37  are disposed at the bottom of the sealed tank  3 . The gas inlet joint  36  communicates with the gas jet tube  4  in the sealed tank  3 , and is connected to a gas supply tube to supply gas into the sealed tank  3  from bottom up. The output joint  37  is used for connecting a liquid supply tube, and the processed high-concentration gas solution is output through the output joint  37 . 
     The following describes an operation mode of the present invention: the liquid is injected into the sealed tank  3  from the top through a liquid tube connected to the liquid supply joint  34 , and maintains a preset pressure. The gas is ejected from the bottom via the gas supply tube through the gas supply tube connected to the gas inlet  36 , and the gas-liquid mixing and dissolving operation is mainly performed among the plurality of the membrane plates  5  in the lower space  33 . The subsequent high concentration gas solution is outputted through the liquid supply tube connected to the output joint  37  for use. However, the excess or undissolved gas in the process may flow through the gas guiding tube  311  to the upper layer area of the upper space  32  by buoyancy to prevent gas bubbles from being accumulated in the lower space  33 , thereby affecting the progress of the dissolution reaction. When the pressure in the sealed tank  3  is higher than a preset value, gas or liquid is discharged through a tube connected to the pressure relief joint  35  for the purpose of reducing pressure. 
     The gas-liquid mixing and dissolution operation of the present invention is mainly performed among the plurality of membrane plates  5  fixed to the periphery of the gas jet tube  4 . The following explains the structure of this part. The plurality of the membrane plates  5  are sleeved over the periphery of the gas jet tube  4 . This manner of attachment can be achieved by a number of configurations, and the present invention is described by only one of embodiments, and does not limit the scope of the invention. As shown in  FIGS. 5 and 6 , the members fixed to the gas jet tube  4  sequentially includes an upper nut  6 , the plurality of membrane plates  5 , a fixing plate  7 , and a lower nut  8 . 
     The gas jet tube  4  is a hollow circular tube with a closed top end (see also  FIG. 4 ), and a plurality of gas jet holes  41  are distributed in the tube wall. The pore size of the gas jet hole  41  is small to facilitate the ejection of many fine bubbles in the liquid. The plurality of gas jet holes  41  can be divided into a plurality of groups according to the height of the plurality of gas jet holes  41 . The plurality of gas jet holes  41  of the same group is distributed at the same height and same angular intervals on the wall of the gas jet tube  4 . In the embodiment, the same height position has four gas jet holes  41  and the four jet holes  41  are spaced at an angle of 90 degrees. The number of groups of the plurality of gas jet holes  41  of different heights is the same as the number of the plurality of the membrane plates  5 , and the positions also correspond to one another. The outer wall of the upper and lower ends of the gas jet tube  4  has a first external thread  42  and a second external thread  43  respectively, and the upper edge of the second external thread  43  has a positioning portion  44  having a smaller outer diameter. The outer wall of the positioning section  44  is not circular. 
     The upper nut  6  has an internally threaded hole  61  at the center for screwing to the first external thread  42 . The central area of the upper nut  6  further includes at least a second liquid flow passage  62 . The second liquid flow passage  62  has a concave opening communicating with the internally threaded hole  61 . The plurality of second liquid flow passages  62  are distributed at equal angular intervals in the internally threaded holes  61 . When the upper nut  6  is locked to the first external thread  42 , the space of the second liquid flow passage  62  existing in the axial direction allows the liquid to circulate. 
     The shapes of the plurality of membrane plates  5  are the same. Now, only a single membrane plate  5  will be described. As shown in  FIG. 7 , the membrane plate  5  is ring in shape to match the inner shape of the sealed tank  3 , but the outer diameter of the membrane plate  5  is smaller than the inner diameter of the sealed tank  3 , and has a central hole  51  in the center, and the central hole  51  is matched with the shape and size of the gas jet tube  4 . The membrane plate  5  includes an inner ring wall  52 , a mixing chamber  53 , and an outer ring wall  54  sequentially from the center outwards. The mixing chamber  53  is a recessed space with the opening facing downward. The inner ring wall  52  is thicker than the outer ring wall  54 . After the two adjacent membrane plates  5  are stacked, a gap exists between the adjacent two outer ring walls  54  for allowing excess gas bubbles and liquid to flow out. The mixing chamber  53  has a concave shape in order to extend the time during which the fine bubbles stay in the mixing chamber  53  to increase the dissolving the gas in the liquid. The axial direction of the central portion of the inner ring wall  52  is further provided with at least an axial passage  55 , and the plurality of axial passages  55  are equiangularly connected to the central hole  51 . The inner ring wall  52  is provided with at least a radial passage  56  and at least a gas passage  57  at different positions in the radial direction. The top wall in the mixing chamber  53  is higher than the radial passage  56  and the gas passage  57 . In the present example, there are four radial passages  56  and are equiangularly distributed. The radial passage  56  is responsible for communicating the axial passage  55  with the mixing chamber  53 . There are four equiangularly distributed gas passages  57 . When assembled, the gas passage  57  corresponds to the gas jet hole  41  and communicates with the mixing chamber  53 . The radial passage  56  and the gas passage  57  are all concave passages whose openings are all downward, and are distributed at an equal angular interval interleaved on the inner ring wall  52 . The radial passage  56  has a greater width and depth than the gas passage  57 . In addition, the inner ring wall  52  is provided with at least a first positioning hole  58  extending in the axial direction, and two positioning holes  58  are provided in this embodiment. 
     The fixing plate  7  is located below the bottommost layer of the plurality of membrane plates  5 , so that the membrane plates  5  located at the bottom layer also can mix gas and liquid. The fixing plate  7  has the same outer shape as the membrane plates  5 , but the intermediate dimension has an elliptical tapered hole  71  smaller than the central hole  51 , and the elliptical tapered hole  71  is the match the outer wall of the positioning section  44  of the gas jet tube  4 . The positioning section  44  is located at the upper edge of the second external thread  43 . In addition, the fixing plate  7  is provided with at least a penetrating second positioning hole  72  in the axial direction, and two second positioning holes  72  are provided in this embodiment. 
     The present invention further is provided with two positioning posts  9 , which can respectively pass through the first positioning holes  58  of the plurality of the membrane plates  5  and the second positioning holes  72  of the fixing plate  7 , thereby maintaining the relative positions of the plurality of membrane plates  5 . The lower nut  8  has an inner threaded hole  81  at the center thereof for locking to the second external thread  43  of the gas jet tube  4 . 
     During assembly, the plurality of membrane plates  5  and the fixing plate  7  are stacked on the periphery of the gas jet tube  4 , and the positioning post  9  is inserted into the plurality of first positioning holes  58  and the second positioning hole  72  to ensure the relative positions of the plurality of membrane plates  5  and the fixing plate  7  are respectively locked to the two ends of the gas jet tube  4  to achieve the overall fixing. Then, the structure is assembled into the sealed tank  3 . For example, the bottom of the gas jet tube  4  is further connected to the gas inlet joint  36 , and the first external thread  42  at the top end of the gas jet tube  4  can be screwed to the center of the partition member  31 . 
     The following describes the actual operation and principle of the present invention. In order to avoid the over-complicated drawing, only 3-4 membrane plates  5  are shown to be stacked and fixed on the gas jet  4 , while up to several tens of membrane plates  5  are actually disposed.  FIG. 8  is a longitudinal cross-sectional view showing the position of the positioning post  9 .  FIG. 9  is a longitudinal cross-sectional view of the radial passage  56 , which is the liquid flow passage.  FIG. 10  is a longitudinal cross-sectional view of the gas passage  57 , which is the gas flow passage. 
     As shown in  FIG. 8 , the membrane plates  5  are placed in a stack on the periphery of the gas jet tube  4 . The positioning post  9  penetrates the first positioning hole  58  of each of the membrane plates  5  and the second positioning hole  72  of the fixing plate  7  at the bottom layer to ensure that the plurality of membrane plates  5  are in the correct orientation. Since the inner ring wall  52  is thicker than the outer ring wall  54 , the adjacent two membrane plates  5  are stacked with a gap between adjacent outer ring walls  54 . 
     As shown in  FIG. 9 , the liquid flow direction is from the top to the bottom inside the sealed tank  3 , and the entire lower layer space  33  is filled outward from the center. The detailed flow direction is: after the liquid fills the upper space  32  of the sealed tank  3 , the first liquid flow passage  313  passing through the partition member  31 , the second liquid flow passage  62  of the upper nut  6 , the axial passage  55  and the radial passage  56  of the membrane plate  5  to fill the entire mixing chamber  53 . Excess liquid flows out through the gap to fill the remaining space of the entire lower space  33 . 
     As shown in  FIG. 10 , the gas is ejected into the sealed tank  3  from below, and the flow direction thereof is: passing through the inside of the gas jet tube  4 , the plurality of gas jet holes  41  on the tube wall, and the gas passage  57  of the membrane plate  5  to the mixing chamber  53 . The dissolved gas-liquid solution or excess bubbles are discharged through the gap. The bubbles are raised by the buoyancy, and the gas-liquid solution is outputted through a tube connected to the output joint  37 . In the present invention, since the diameter of the gas jet hole  41  is extremely small, after the high-pressure gas is ejected through the gas jet hole  41  and aligned with the gas passage  57 , fine bubbles are generated in the mixing chamber  53 , and the contact area between the bubbles and the liquid is increased. The concave portion of the mixing chamber  53  can extend the time the bubbles staying inside the mixing chamber  53 , thereby increasing the gas-liquid dissolution. In addition, the liquid is ejected through the radial passage  56  to generate a liquid jet to the mixing chamber  53 . The liquid jet, by further dispersing the bubbles to make the bubbles finer, increases the contact area, and prevents the bubbles from stopping to flow and to accumulate inside the mixing chamber  53  to affect the progress of the gas-liquid dissolution. Due to the tens of layers of the membrane plates  5  in the sealed tank  3 , the total contact area is relatively increased by tens of times, and the overall dissolution is also greatly improved. 
     In summary, the gas-liquid dissolving apparatus of the present invention is disposed with a plurality of membrane plates  5  in a stacked manner on the periphery of the gas jet tube  4  inside the sealed tank  3  to form up to tens of stacked mixing chambers. In a high pressure state, the liquid is supplied from the top and the gas is ejected from the bottom, and the fine bubbles in the mixing chamber  53  continuously stays in contact with the liquid with a large area and prolong the contact time, so that the gas is dissolve into the liquid, and a large amount of high-concentration gas-liquid solution is generated. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.