Abstract:
An external cultivation liquid siphon includes a liquid delivery equipment located in a cultivation liquid storage tank to continuously pump cultivation liquid to a plant cultivation pot and an external siphon equipment to bridge the cultivation liquid storage tank and the plant cultivation pot. The external siphon equipment has a tubular facility with variations in tubular diameters to generate siphonage action to fill the tubular facility with flowing liquid. Thus the cultivation liquid pumped by the liquid delivery equipment to the plant cultivation pot can circulate reciprocally between an upper liquid level and a lower liquid level to cultivate plants.

Description:
FIELD OF THE INVENTION 
     The present invention relates to an external cultivation liquid siphon and particularly to a cultivation liquid siphon that provides circulation of cultivation liquid without adding electronic control elements. 
     BACKGROUND OF THE INVENTION 
     Aquaponics system functions mainly based on a principle of creature interaction that is existing in the nature. It is an eco-system in which plants, fishes, bacteria or microbes are fundamental elements, and excrements of the fishes are transformed to nutrients of plants. In a broader sense aquaponics is an eco-culture or composite cultivation technique. In practice the system generally adopts an approach of nitrifying waste water of culture farming through bacteria to produce nutrients needed by growing of plants. The waste water is finally transformed to the nutrients needed by the plants and absorbed. The water also is purified in the process. Hence the entire aquaponics system is eventually a closed water circulation system. It provides the advantage of culture farming without the need of changing water and growing vegetables without the need of watering. Meanwhile, the aquaponics system also incorporates microbes activities, hence is an organic cultivation and culture technique, and can provide more natural and healthy foods to people. 
     A conventional aquaponics system  1  is designed in a concept as shown in  FIG. 1 . It mainly includes a bell siphon  11  which consists of a bell hood  111 , an inner tube  112  and an external air tube  113 . The bell hood  111  has a plurality of apertures  114 . A cultivation liquid storage tank  12  is provided which has a liquid pumping device  13  located inside to continuously pump liquid to a plant cultivation pot  14 . When the cultivation liquid enters the bell hood  111  through the apertures  114  and reaches an upper spot of the inner tube  112 , namely the upper liquid level where a plurality of cultivated plants  15  can absorb the cultivation liquid, if the cultivation liquid flows out through the inner tube  112  at a sufficient amount to form a water film and make the pressure inside the bell hood  111  smaller than the external atmospheric pressure, the bell siphon  11  generates a siphonage action, and the external atmospheric pressure pushes the cultivation liquid to flow back to the cultivation liquid storage tank  12 . When the cultivation liquid drops to a lower liquid level the external air enters the bell hood  111  via the external air tube  113  to break liquid column and stop the siphonage action, then the cultivation liquid stop flowing back. Therefore the liquid level in the plant cultivation pot  14  reaches the lower liquid level to allow the roots of the cultivated plants to breath with oxygen. At the same time, the liquid pumping device  13  continuously pumps the cultivation liquid until reaching the higher liquid level to achieve circulation of the cultivation liquid, thereby make cultivation of the plants possible. 
     However, all the present bell siphon  11  adopts the internally built approach and is embedded in the plant cultivation pot  14 , and is prone to skewing and results in failure of generating siphonage action desired, or has the inlet of the cultivation liquid jammed by dirt, stones or external objects that prohibits external air from entering the siphon air chamber to break the liquid column This makes the siphonage action fails to stop the liquid pumping device  13  to pump the cultivation liquid to the plant cultivation pot  14  and maintain the siphonage action to allow flow back of the cultivation liquid to the cultivation liquid storage tank  12  to keep liquid balance as desired. Namely, the liquid level in the plant cultivation pot  14  cannot rise to the higher liquid level to allow the plants  15  to get the cultivation liquid, but merely maintain at the lower liquid level, thus fails to achieve the liquid level circulation effect. In addition, the bell siphon  11  also has the external air tube  113  as shown in  FIG. 1  to aid entry of external air when the actual liquid level drops to the lower liquid level, but it still does not improve the problems of skewing of the bell siphon  11  installation angle and jamming of the external objects. 
     Taiwan Patent Nos. M473049, M465006 and I388278 disclose various complex mechanisms that use a timer to interrupt pumping of cultivation liquid. However, the aquaponics system basically aims to adopt the concept of natural circulation function with minimum electronic devices. The aforesaid prior techniques, although can partly fix the problem, actually contradict this concept. 
     SUMMARY OF THE INVENTION 
     The primary object of the present invention is to overcome the problem of the conventional bell siphon of installed in the plant cultivation pot that results in unable to generate stable siphonage action. 
     To achieve the foregoing object the present invention provides an external cultivation liquid siphon to bridge a plant cultivation pot and a cultivation liquid storage tank to provide reciprocal siphonage action. It includes a liquid delivery equipment and an external siphon equipment. The liquid delivery equipment includes a liquid pumping device located in the cultivation liquid storage tank and a liquid delivery pipe to bridge the liquid pumping device and the plant cultivation pot. The external siphon equipment defines an upper liquid level in the plant cultivation pot corresponding to a plant cultivation location and a lower liquid level away from the plant cultivation location. The external siphon equipment is coupled with a liquid input tube corresponding to the lower liquid level. The liquid input tube is connected to a inverse U-shaped tube corresponding to the upper liquid level via a first connection tube. The inverse U-shaped tube has another end connected to a liquid discharge tube of the cultivation liquid storage tank via a second connection tube to output the cultivation liquid. The liquid discharge tube and the second connection tube are bridged by an intermediate tube . The second connection tube has an inner diameter greater than the inner diameter of the intermediate tube. The liquid discharge tube also has an inner diameter greater than the inner diameter of the intermediate tube. 
     In one embodiment the liquid input tube in the plant cultivation pot is coupled with a siphon ancillary member which has an open end located at the lower liquid level and a closed end higher than the liquid input tube, and an installation space between the closed end and the open end. The installation space has a space between the liquid input tube and the closed end to be defined as a siphon air chamber. 
     In another embodiment the open end is coupled with an isolation member. 
     In yet another embodiment the liquid discharge tube has a bend section adjacent to the coupling location of the intermediate tube. 
     In yet another embodiment the first connection tube and the inverse U-shaped tube are formed by bending a same tube. 
     In yet another embodiment the liquid input tube, the first connection tube and the inverse U-shaped tube are formed by bending a same tube. 
     In yet another embodiment the liquid input tube, the first connection tube, the second connection tube and the inverse U-shaped tube are formed by bending a same tube. 
     In yet another embodiment the intermediate tube has a coupling section located in the second connection tube formed at a length smaller than another coupling section of the intermediate tube at the liquid discharge tube. 
     In yet another embodiment the intermediate tube has a coupling section located at the second connection tube with a siphon ancillary sloped surface formed at the upper end thereof. 
     In yet another embodiment the liquid input tube is coupled with an isolation member. 
     In yet another embodiment the inverse U-shaped tube has a horizontal section which also can be an arched section. 
     By means of the construction set forth above, compared with the conventional structure, the invention provides features as follows: 
     1. The external siphon equipment of the external cultivation liquid siphon is located outside the plant cultivation pot, hence can reduce the size of the plant cultivation pot occupied by the external siphon equipment. Through installed outside, the external siphon equipment also can avoid from being impacted during the plants are reaped that might otherwise affect generation of siphonage action. In addition, being positioned outside, malfunction of the external siphon equipment can be easily detected. 
     2. The inverse U-shaped tube, the second connection tube, the liquid discharge tube and the intermediate tube are formed at tubular dimensions related to each other and can be selected to generate siphonage action more efficiently. 
     3. The siphon ancillary member of the external siphon equipment can resolve the problem of unstoppable siphonage action caused by ineffective control of liquid discharged amount resulted from liquid delivery amount and siphonage action at the final period, and also ensure that air can enter to break the liquid column to stop siphonage action. 
     4. The liquid input tube or the open end of the siphon ancillary member can be coupled with the isolation member to block external objects or dirt or stones from entering so that the inlet is not jammed that might otherwise hinder entering of the external air in the siphon air chamber to break the liquid column. 
     The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of the structure of a conventional bell siphon. 
         FIG. 2  is a schematic view of the structure of the external cultivation liquid siphon of the invention. 
         FIG. 3  is a schematic view of the structure of the external siphon equipment of the invention. 
         FIGS. 4A through 4C  are schematic views of the external cultivation liquid siphon of the invention in siphonage actions to circulate cultivation liquid. 
         FIG. 5  is a schematic view of another structure of the external siphon equipment of the invention. 
         FIG. 6  is a schematic view of yet another structure of the external siphon equipment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please referring to  FIGS. 2 and 3 , the present invention aims to provide an external cultivation liquid siphon  2  mainly to bridge a plant cultivation pot  3  and a cultivation liquid storage tank  4  to provide reciprocal siphonage action that is applicable to an aquaponics system or for circulation of cultivation liquid in a hydroponics system. The external cultivation liquid siphon  2  includes a liquid delivery equipment  21  and an external siphon equipment  22 . The liquid delivery equipment  21  includes a liquid pumping device  211  located in the cultivation liquid storage tank  4  and a liquid delivery pipe  212  to bridge the liquid pumping device  211  and the plant cultivation pot  3 . The liquid pumping device  211  can be a submerged pump. The plant cultivation pot  3  and the external siphon equipment  22  are bridged by the external siphon equipment  22  which also defines an upper liquid level H corresponding to a plant cultivation location in the plant cultivation pot  3  and a lower liquid level L away from the plant cultivation location. The external siphon equipment  22  further is connected to a liquid input tube  221  corresponding to the lower liquid level L. The liquid input tube  221  has another end bent or connected to an elbow tube to connect to a first connection tube  222  which is further connected to a inverse U-shaped tube  224  corresponding to the upper liquid level H. The inverse U-shaped tube  224  has a horizontal section  223  which also can be an arched section  223   a  as shown in  FIG. 5 . The inverse U-shaped tube  224  has another end connected to a liquid discharge tube  226  via a second connection tube  225  to deliver the cultivation liquid to the cultivation liquid storage tank  4 . The liquid discharge tube  226  and the second connection tube  225  are bridged by an intermediate tube  227  which has an inner diameter smaller than that of the second connection tube  225  and the liquid discharge tube  226 . The second connection tube  225  and the liquid discharge tube  226  can be formed at a same tubular diameter. The first connection tube  222  and the inverse U-shaped tube  224  can also be formed by bending a same tube, or the liquid input tube  221 , the first connection tube  222  and the inverse U-shaped tube  224  can also be formed by bending the same tube, or the liquid input tube  221 , the first connection tube  222 , the second connection tube  225  and the inverse U-shaped tube  224  can also be formed by bending the same tube. 
     Please refer to  FIGS. 4A through 4C  for the external cultivation liquid siphon  2  of the invention in use for circulation of the cultivation liquid. The liquid pumping device  211  draws the cultivation liquid from the cultivation liquid storage tank  4  and injects to the plant cultivation pot  3  via the liquid delivery pipe  212 . The cultivation liquid accumulates gradually until reaching the upper liquid level H as shown in  FIG. 4A  so that a plurality of plants  15  cultivated in the plant cultivation pot  3  can absorb the cultivation liquid. Meanwhile, the horizontal section  223  of the inverse U-shaped tube  224  also is filled with the cultivation liquid due to rising of the liquid level. Because of tubular diameter differences among the second connection tube,  225 , the intermediate tube  227  and the liquid discharge tube  226 , a siphonage action of filling and flowing the liquid in the tubes takes place; incorporated with the gravity of the cultivation liquid and the atmospheric pressure, the cultivation liquid quickly flows through the liquid input tube  221 , the first connection tube  222 , the inverse U-shaped tube  224 , the second connection tube  225 , and the intermediate tube  227  and discharged through the liquid discharge tube  226  to the cultivation liquid storage tank  4 , and the liquid level drops as shown in  FIG. 4B . To facilitate generation of the siphonage action, aside from forming the tubes in different diameters, the liquid discharge tube  226  has a bend section  228  adjacent to a coupling location of the intermediate tube  227 , or the intermediate tube  227  can have the coupling section located in the second connection tube  225  and formed at a length smaller than another coupling section of the intermediate tube  227  located in the liquid discharge tube  226 ; and as shown in  FIG. 6 , the intermediate tube  227  can also have a siphon ancillary sloped surface  229  formed at an upper end of the coupling section located in the second connection tube  225 . Thereby, a liquid column filled the tubes can be generated easier, and when the liquid level drops to a location as shown in  FIG. 4B  external air can enter via the liquid input tube  221  to break the liquid column and stop the siphonage action. 
     Please also referring to  FIG. 2 , in order to ensure that the siphonage action is stopped as desired, the invention also provides a siphon ancillary member  23  on the liquid input tube  221  in the plant cultivation pot  3 . The siphon ancillary member  23  has an open end  231  located at the lower liquid level L and a closed end  232  higher than the liquid input tube  221 , and an installation space  233  between the closed end  232  and the open end  231 . The installation space  233  has a space between the liquid input tube  221  and the closed end  232  to be defined as a siphon air chamber. In the event that liquid delivered amount during injecting of the liquid to the plant cultivation pot  3  and liquid discharged amount at the final stage of the siphonage action are abnormal due to improper control operation that results in balance of liquid amount unable to stop the siphonage action, through the siphon ancillary member  23  as shown in  FIG. 4B , when the liquid level reaches proximate to the lower liquid level L and if the siphonage action does not stop, when the liquid level reaches the position substantially at the horizontal position of the open end  231  of the siphon ancillary member  23  as shown in  FIG. 4C , the atmospheric pressure difference allows the air to enter to break the liquid column and stop the siphonage action. In addition, the liquid input tube  221  or the open end  231  of the siphon ancillary member  23  can be coupled with an isolation member  234  to prevent external objects or dirt or stones from entering. 
     As a conclusion, the external cultivation liquid siphon  2  of the invention has the external siphon equipment  22  located outside the plant cultivation pot  3 . The tubular sizes of the external siphon equipment  22  can be selected to generate siphonage action more efficiently. In addition, the siphon ancillary member  23  can effectively solve the problem of failing to stop the siphonage action caused by improper liquid delivered amount or control failure of liquid discharged amount at the final stage of siphonage action. Furthermore, the liquid input tube  221  or the open end  231  of the siphon ancillary member  23  can be coupled with the isolation member  234  to block external objects or dirt or stones from entering, thereby external air can enter the siphon air chamber without being hindered to break the liquid column. 
     While the preferred embodiments of the invention have been set forth for the purpose of disclosure, they are not the limitation of the invention, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.