Abstract:
Electrical energy is generating by submerging a tank in a body of water so that its water inlet is located under a water surface and covered by water and water flows into an interior of the tank, evacuating water from the tank by an evacuating element through a water outlet of the tank to maintain in the interior of the tank a space for flowing water through the inlet into the interior of the tank, arranging a converting element which convert energy of the water flowing into the interior of the tank into an electrical energy, and arranging the evacuating element so that its discharge is located below the outlet of the tank and above the water surface.

Description:
CROSS-REFERENCE TO A RELATED APPLICATION 
       [0001]    This patent application is a continuation of U.S. patent application Ser. No. 12/802,260, filed on Jun. 3, 2010, it incorporates the subject matter of the above-identified application and claims its priority from the priority date of the above-identified application. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to a method and an apparatus for generating electrical energy with the use of water. 
         [0003]    Method and apparatus of this type are known in the art. U.S. patent application publication US 2008/0211231 discloses a device consisting of a container which is partially submerged in the sea in which force of the water flowing through the pipes causes turbines to rotate thus generating electricity which may be transmitted to land. 
         [0004]    U.S. patent application publication 2009/0173404 discloses a system for providing a structure or structures for altering water surface temperature having a holding vessel with a wall extending above a water level and a submerged lower portion, with a conduit extending to a water depth. 
         [0005]    International patent application publication WO 00/31412 discloses a unit for production of electric power using the energy of the sea water which changes kinetic and potential energy of waves into energy of position, based on differences in height. 
         [0006]    International patent application publication WO 2005/106240 discloses a method for energetic technical and biological use of underground water in which water flows from a depth of water at hydrostatic pressure through pipes arranged in a wall built on solid ground, towards hydraulic turbines driving generators and/or other technical installations or devices to be driven. Water from the turbines then flows toward aquaculture structures installed deeper where the water is used to grow aquatic plants and rear aquatic animals or is used for technical purposes. 
         [0007]    British patent GB 2,456,333 discloses a tidal pump system in which a water powered pump is actuated by variable water levels (e.g. tidal energy.) The pump may pump water between different depths within the water, e.g. to adjust nutrient levels or temperature, or it may pump fluids or fluent solids to or fro the water e.g. to provide materials, or to store gasses below water. 
         [0008]    French patent FR 2,813,925 discloses electricity generation by tidal flow pressure using rising tide to transfer fresh water to a floating reservoir which then supplies a fixed reservoir via a turbine during ebbing tide. 
         [0009]    U.S. patent application publication to Robichaud 2009/0230687 discloses a system of generating electrical energy, in which an underwater fall rotates a turbine to generate electricity, and a corkscrew driven by the turbine evacuates water. The rotation of the corkscrew is caused by the rotation of the turbine, not independently from the turbine, and therefore the corkscrew cannot generate more power than the power of water falling on the turbine and cannot evacuate the water under the turbine efficiently to create under the turbine an air-filled space which is necessary for the rotation of the turbine. (Ilya, is it OK to say anything about “air-filled space” and to create more arguments with the Examiner ?) 
         [0010]    It is believed that the existing methods and apparatus for generating electrical energy can be further improved. 
       SUMMARY OF THE INVENTION 
       [0011]    It is therefore an object of the invention to provide a method and apparatus for generating electrical energy which is a further improvement of existing methods an apparatuses. 
         [0012]    In keeping with these objects and others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a method of generating electrical energy from water, comprising the steps providing a tank having an inlet and an outlet; submerging the tank in a body of water so that the water inlet is under a water surface and covered by water and water flows into an interior of the tank; evacuating water from the tank through the outlet so as to maintain in the interior of the tank a space for flowing the water through the inlet into the interior of the tank; and arranging converting means which convert energy of the water flowing into the interior of the tank through the inlet into an electrical energy; operating the evacuating means independently of an operation of said converting means; and providing in the tank means for directing the water, flowing into the tank to act primarily on blades of the converting means. and arranging the evacuating means so that its outlet is located below the outlet of the tank and above the water surface. 
         [0013]    Another feature of the present invention resides in an apparatus of generating electrical energy from water, comprising a tank having an inlet and an outlet and submerged in a body of water so that the water inlet is under a water surface and covered by water and water flows into an interior of the tank; means for evacuating water from the tank through the outlet so as to maintain in the interior of the tank a space for flowing the water through the inlet into the interior of the tank; and converting means converting energy of the water flowing into the interior of the tank through the inlet into an electrical energy, operating the evacuating means independently of an operation of said converting means; and providing in the tank means for directing the water, flowing into the tank to act primarily on blades of the converting means. and arranging the evacuating means so that its outlet is located below the outlet of the tank and above the water surface. 
         [0014]    The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  shows a submerged into the water apparatus for creation of underwater falls according to the present invention; 
           [0016]      FIG. 2  is a sectional perspective view of an embodiment, which creates continuously working in depth of the river “underwater falls” rotating the turbine, and use gravity for a water evacuation system, according to the present invention; 
           [0017]      FIG. 3  is a partial perspective view of an embodiment of apparatus, which creates continuously working underwater falls in depths of the ocean, rotating turbine and using energy of the low and high tides for water evacuation system, according to the present invention, 
           [0018]      FIG. 4  shows a perspective view of the centrifuge, used in mechanical water evacuating system of apparatus according to the invention, 
           [0019]      FIG. 5  is an apparatus corresponding to the apparatus for  FIG. 1 , but with mechanical (centrifuge) water evacuation system, working inside of any large body of water for generating electrical energy according to the present invention; 
           [0020]      FIG. 6  shows some other mechanisms (marine propeller) to evacuate water from the tank of the apparatus for generating electrical energy according to the present invention; 
           [0021]      FIG. 7  is an apparatus with a vertical water turbine for generating electrical energy according to the present invention; 
           [0022]      FIG. 8  is a view showing an apparatus for generating electrical energy, equipped with a new system of evacuation of water according to the present invention; 
           [0023]      FIG. 9  is a view showing an apparatus for generating electrical energy, with a plurality of pumps activated by gravity according to the present invention, and 
           [0024]      FIG. 10  is a view showing an apparatus for generating electrical energy, with a self-propelled pump according to the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0025]    The present invention relates to a method and an apparatus, which convert energy of slow moving water of ocean, river, lake into highly efficient kinetic energy of the underwater falls, capable to rotate, for example, turbine, and thereby to produce electrical energy. Shown in the drawings and described herein below in details are preferred embodiments of the invention. It is to be understood, however, that the present disclosure is an exemplification of the principles of the invention to the illustrated embodiments. 
         [0026]      FIG. 1  shows a “Funnel effect”. If the top rim  3  of the empty tank  4  is pushed slightly under the water  1 , the water  35 , that is above the rim, immediately begins to flow inside of tank  4  via its inlet, creating a funnel  2  on the water surface and leaving a central area of the tank  7  free of water. Tubular shaped water is falling free to the bottom  34  of the tank  4  until the tank is full. This short living waterfall produces an energy of the free falling water and opens a possibility to convert it into electrical energy. 
         [0027]      FIG. 2  shows a schematic view of the central section of an apparatus according to the invention, that can produce a large volume of the useful energy. Apparatus is based on the river floor, supported by standoffs  25  and base  26 , located under the bottom  33  of the river. A tank  23  has an open top which forms an inlet and the top rim  23 ′; the bottom  22  has an opening  31  which forms an outlet. Concentrically to the cylindrical (for instance) wall of tank  23  is inserted a sealed barrel  11 , which forms an insert, with cylindrical wall  29  and the bottom  28 , taking the place of space  7  from  FIG. 1 . The barrel  11 , supported by plurality of horizontal tubings  19 , is attached to the inner side of wall  23  of the tank, creating a solid frame of the apparatus with the empty tubular space between walls  23  and  29 . 
         [0028]    The barrel (insert) is elevated above the top rim  23 ′ of the tank. When top rim of the tank  23 ′ with the inlet is pushed inside of water  13  below its top surface  5 , the water  6 , located above the tank, begins to flow rapidly inside of the empty tubular space, creating a waterfall. Right under the barrel  11  is placed the turbine  20  and the central output shaft  8 , to which the turbine is attached, and which is supported by bearings  24 . The free falling water of the waterfall  6  and  30  is reaching first, on its way downward, the blades  21  of turbine  20 , forcing the turbine to spin. The turbine, being attached to the central output shaft  8 , forces the shaft to rotate and through the coupling  9 , rotates the shaft  10  of the electrical generator, thus producing electricity. After contacts with the blades of the turbine, water continue to fall downward to the floor  22  of tank; here it is ready for evacuation. There are mechanical ways to evacuate water, collected on the bottom of the tank as will be shown below.  FIG. 2  shows the simplest natural way of water evacuation by gravity, which is possible for river power stations: each river has an elevation over the ocean surface and this is the reason why river water is moving toward the ocean. For instance, a Potomac river flows along Atlantic coast of the USA, the river length is 383 miles and the elevation is 3060 ft. 
         [0029]    In  FIG. 2  line  12  represents a top surface of river and lines  17 ,  18  and point  32  represents the bottom of the river. The broken lines show the elevation of the river in given areas. The bottom  22  of the tank  23 , where the water, that just passed turbine  20 , is collected, is marked on sketch by line  14 . Water collected on the floor  22  runs through the opening  31  into the pipe  27  down to the river floor  32  by gravity, Free end  16  of pipe  27  is lifted above the top water surface to point  15 , that is lower than line  14 , or lower than bottom  22  of tank  23  and therefore of the outlet of the tank, where evacuation of water begins under the action of gravity. Therefore, water, collected in the pipe  27  will flow out into the open air  15 , following the STEVIN&#39;s Law concept of communicating vessels, and back to the river. This situation makes possible for turbine  20  to work continuously. The output power of turbine strictly depends on it size, configuration and how deep in the water it is located, in other word, how far downward the water from the tubular space of the apparatus is falling before it reaches the blades of the turbine. 
         [0030]    For this apparatus, non-metallic materials are used mostly, like reinforced fiberglass, plastic etc. Before installation is completed, the whole system should be free of surrounding water: turbine will begin to rotate only, if waterfall will run into the empty tubular space of the tank and evacuation of water is ready. Further will be shown ON/OFF mechanism of the apparatus. The pipe  27  can be located as a straight angled line from the housing  22  to the point  16  in the air. 
         [0031]      FIG. 3  shows another apparatus for creation of “underwater falls”, that is designed to work in the depth of an ocean or a sea, and uses energy of low and high tides to operate the water evacuating system. It comprises a few elements with the same functions, as in  FIG. 2 : cylindrical tank  128  with an open top forming the inlet, empty sealed cylindrical barrel  122 ′; tubings  106  attaching concentrically inner side of the wall of the tank and outer side of the wall of the barrel, creating a solid frame of apparatus and an empty tubular space between walls. Shown turbine  136  with a shaft  125 , to which turbine is attached, and bearings  110  to keep apparatus intact. 
         [0032]    The apparatus has a floating platform  108  with supporting balloons (for instance)  102 , keeping platform constantly over the water level  120 . On the bottom of the ocean a few cylindrical standoffs  124  are installed, that are protruding a floating platform  108  through the holes  109 , slightly larger in diameter, than diameter of standoffs  124 , allowing platform  108  to move only vertically during low and high tides, and, therefore, keeping a distance between the platform  108  and the top surface of the water  120  constant. A tank is placed on a small platform  129 , which is attached to the floating platform  108  by plurality of tubings  107 , and therefore, is moving up and down together with a platform  108 . In the present position water  121  from above the tank rapidly flows into an empty tubular space of apparatus, creating a waterfall, and, when it reaches blades of the turbine  136 , causing turbine to rotate. Turbine, further, rotates the central shaft  125 , to which it is attached and the central shaft, in turn, rotates thru coupling  100  the shaft of electrical generator  101 , which produces electricity. 
         [0033]    After turbine  136 , water continues to fall downward to the floor of the tank and here it is ready for evacuation from the tank. Evacuation system is operated by forces of low and high tides of the ocean or the sea: from the tank, water, collected on its bottom, via flexible tubings  127  and  130 ′, flows through the tank outlet by gravity into plurality of pairs, upper  129  and lower  131 , of water receptacles (containers), which are located lower than the tank. The receptacles are the collapsible tanks (or are the cylinders with the plungers) Each flexible tubing has a check valve, upper  130  and lower  126 , to prevent water from running back into the tank. Upper receptacle  129  is attached from the bottom to the stationary platform  119 , which is a part of standoff  124 , and from the top, to the moving platform  117 , which is attached to the floating platform  108  by the tube  114 . The lower receptacle  131  is attached from the top to the stationary platform  119  and from the bottom to the moving platform  132 , which is attached to the floating platform  108  by the tube  116 . 
         [0034]    During the low tide platform  108  goes down and presses receptacle  129  to stationary platform  117 , creating inside of the receptacle  129  pressure, which closes the check valve  130  and pushes water, collected inside of the receptacle, outside by evacuating tubing  113 , the top end of which is placed above the water surface. At this time platform  132 , being attached to moving down platform  108 , stretches receptacle  131  and opens the check valve  126 , allowing water from the bottom of the tank to flow inside of receptacle  131  by gravity. All water evacuating tubings extend through top platform  108  via the holes  135 . At the end of the low ocean tide the receptacles taking turn and now, moving up platform  108  pulls the platform  117  up, opening a check valve  130  and allowing water from the tank to flow down into the receptacle  129  by gravity. At the same time, the moving up platform  108  and the tubing  116  are compressing receptacle  131 , closing the check valve  126  and pressing water out from receptacle  131  to the open air via evacuating tubing  118  or back to water. 
         [0035]    Apparatus has an ON/OFF device  112 , which, when needed, stops water from falling inside of tank. This device is a cylinder  112  with double walls  112  and  112 ′, which are connected from the top by solid ring  105 , enclosing these walls from the top. Diameter of said double wall “locking” cylinder is, approximately, equal to the diameter of the stationary wall of the tank  128 , which allow cylinder  112  to slide up and down on it. In the working position of apparatus this locking cylinder is in its lower position, when the top ring  105  of this cylinder is sitting right on the top rim  111  of the tank, and water from above the locking cylinder is running freely into the tank. When said cylinder is in the top position, the top ring of it  105  is above the water surface and prevents surrounding water to get into the tank, and stops the operation of the apparatus. 
         [0036]      FIG. 4  shows a perspective view of centrifuge, with its flat horizontal base  63 , a plurality of vertical ribs  64  and the central hub  65 , used in  FIG. 5 . 
         [0037]      FIG. 5  shows an apparatus for creation of “underwater falls” for converting energy of slow moving water of ocean, river, lake into the highly efficient kinetic energy of free falling water, capable to rotate the turbine and to produce electricity. The apparatus is based on standoffs  56  and base  57  in the bottom of the ocean. The difference between this apparatus and the one shown in  FIG. 2 , is in the method of evacuation water, collected on the bottom of the tank of the apparatus. Here again, the apparatus has a cylindrical tank  45  with an open top forming an inlet and the top rim  45 ′, the barrel  39  with cylindrical wall  43  and the bottom  50 . The barrel is attached to the inner side of the wall  45  by plurality of tubings  48  and  49 , making the frame of apparatus strong and reliable. The main purpose of the barrel is to create a tubular space between walls  43  and  45  and to fill up the space  36  in the center of tank, leaving it free of water. This will allow to make the tank tall as needed, in order to increase its elevation above water level, it can be used as a platform for electrical generator and all the necessary parts, that go with it. On the central output shaft  42 , right under the barrel  39 , is placed turbine  46  with its blades  51 . Turbine is attached to the central shaft  42 , which is supported by bearings  59 . 
         [0038]    When apparatus is submerged into the ocean or river so that its inlet is under water, water from above the tank flows rapidly into the empty tubular space of apparatus, creating a waterfall, which is running downward to the blades  51  of turbine  46 , forcing the turbine to spin. Being attached to the same central shaft, the turbine rotates and through the coupling  41 , rotates shaft of the generator, producing electricity. A few mechanical methods of water evacuation from the tank are described below. To the same central shaft  42  with turbine  46  is attached a centrifuge  58 . The lower portion of the tank  45 , below the turbine, is conical  62  for better control of the water movement. All water, that just passed the turbine blades, is directed to the center of the rotating centrifuge  58 , where it is caught between ribs  64  and hub  65  extending above ribs hub  65  ( FIG. 4 ). This allows water between ribs to move out from the center of hub  65  in the point, where centrifugal forces are already sufficient. Portion of the wall  47  of tank helps to lock water between ribs. Substantial centrifugal force pushes the water out from the bottom of tank  66  to the chamber  61 , creating pressure, sufficient enough to push water through the opening  60  of the chamber  61  into the tube  44 , which is elevated above the water surface  37 , and has a normal atmospheric pressure inside. Water evacuates in point  38  and goes back into the ocean or river. 
         [0039]    Another possible solution of water evacuation from the tank of the apparatus shown is from side “A”. In some cases, depending on the pressure inside the water, it is feasible to seal the bottom of the tank with the elastic circular check valve  53 , which opens under the pressure of centrifugal forces, and all the water, collected on the bottom of tank, flows out through the opening  54  back to the ocean (river). Check valve  53  will not allow water to go back inside of tank. 
         [0040]      FIG. 6  shows another method for evacuation of water from the bottom of tank. Same functional parts fare similar to those in  FIG. 5 : turbine  78  with blades  73  and central shaft  84 , barrel  70 , flowing water  76  from above the tank  77 , electrical generator  71  driven by central shaft  84 , top water surface  74  and evacuating tubings, with low atmospheric pressure inside. At the lower part of apparatus a new mechanism is provided for evacuating water from the bottom of tank. Conical portion  79  of body of tank  77  is made to direct water, that just passed turbine blades  73  into a chamber  81 , where a propeller  80  is installed and attached to the same central shaft  84  as turbine  78 . Propeller is similar to propeller of the ship—simple and very efficient, enough to create high pressure in front of itself. Being driven by the force of the turbine, the propeller will push water from chamber  81  back to surrounding water  82  or to the open air  72  via plurality of evacuating tubing&#39;s  83  and  75 . 
         [0041]    If it is needed to increase revolutions of propeller, centrifuge etc. the gear box can be added inside of tank. All mechanical additions to apparatus however are driven by central shaft and are take some energy from the turbine, but this is only a small portion of the full amount of energy, produced by the turbine. These and other apparatuses the with mechanical type of evacuation of water from the tank to open air can be a model for a “Personal power station” for domestic use. 
         [0042]      FIG. 7  shows an apparatus that converts energy of slow moving water into highly efficient kinetic energy of free falling water, capable to rotate turbine and produce electricity, that uses a vertical turbine. The turbine  95  is attached to the shaft  92  inside of rectangular tank  87  with two pairs of flat walls  88  and  90 , with the bottom  89  and the top side  96 . The turbine is supported by bearings  99  and the front and back walls  89 . The turbine has a plurality of blades  86 . In the top plate of tank  96  there is a rectangular opening  97  forming an inlet, size and location of it is designed to supply a maximum of free falling water  98  from the opening  97  to one side of the turbine blades  86 , to force the turbine to spin. Turbine will rotate a central shaft  92 , which will then rotate the shaft of the electrical generator to produce electricity. The water, collected on the bottom of tank will be evacuated through an opening  93  of tubing  94 . Water evacuating system, gravitational, mechanical or even by pumps, that will be used, depends on the location of the apparatus in the water. 
         [0043]      FIG. 8  shows a partial section of an apparatus, equipped with a new system of evacuation of water from the tank by gravity, practically, without use of capacity of the turbine. There are two parts of the apparatus: the top part has a waterfall producing tank  142  with the turbine  143  that rotates the shaft  141 , and the barrel  140  that is creating tubular falls (in this case for horizontal turbine) to activate turbine blades. In addition, a rotating tubular sleeve  154  is attached to the bottom of the tank. Diameter of this sleeve guaranties, that all water, entered the tank will be evacuated though this rotating sleeve, without being collected inside of the tank. In the lower part  161  of the apparatus is shown front section of the water evacuating system, that consists a plurality of stationary pumps, activated by the weight of the water, supplied in sequence from the rotating sleeve. The top view of pumps and the working technology that makes all pumps successfully evacuate water from the tank  161  are shown in details and described in  FIG. 8 , section D-D, and  FIG. 9 . 
         [0044]      FIG. 9  shows a top view of a plurality of stationary pumps  151  (5 in this case), activated by gravity. Pumps are placed in circle, one after another, in the lower portion of the tank  155 . Also, shown is a rotating lever/tubular sleeve  150 , which is driven by central shaft of the apparatus. The sleeve rotates with a permanent speed above said pumps. It accepts all the water from the bottom of the tank and, while rotating, passes it through into the plunger of each pump in sequence. For one 360° revolution this sleeve supplies an equal amount of water, approximately, a half of the volume of each pump, just enough to fill up the lower portion of the pump, located under the plunger. Two adjacent pumps A and B are chosen to show their operation. 
         [0045]      FIG. 10  shows in details three working steps of each self propelled pump, making possible to evacuate the water from the bottom of the tank, disposed by rotating sleeve into the plungers of said pumps. Construction of pumps are identical. Shown here, are three positions A 1 , A 2  and A 3  of the same working pump A within three full revolutions of the sleeve, that rotates above pumps with a permanent speed and, while moving, discharges an equal amount of water into each pump sequentially. Each pump consists of a housing  147 , a plunger  144 , O-rings  146  to separate hermetically the plunger from the housing, a compression spring  148  that in the open position supports an empty plunger, and it is fully compressed when plunger is filled with water. At the bottom  163  of the plunger  144  is placed a normally open check valve, a floating ball  160 , that is kept in a short proximity with the opening  161  in the plunger&#39;s bottom  163  by pins  159 . The normally closed check valve  157  is installed on the bottom  162  of the chamber  164 . A pin  156  is fixed to the bottom of the housing. When plunger is filled with water, it is moving down, being activated by weight of the water, and at the end of its travel the pin  156  gets in contact with the ball  160 . 
         [0000]    The working steps are: 
         [0046]    Step 1 is represented by A 1 : rotating sleeve moves above the pumps and, during its movement above the plunger of the pump A, discharges into it enough water to fill-up the lower chamber  164  at the bottom of the housing. Because the check valve at the bottom of the plunger is open at this time (the ball is in the “down” position by gravity) the water from the plunger flows freely into the chamber  164  of the housing  147 . When calculated amount of the water is supplied, the sleeve moves to the next pump B (from  FIG. 9 ) etc., filling-up in one 360° revolution the lower chambers of all pumps. Because the check valves  157  on the bottom of the housings are closed, supplied water remains inside of the chambers. Rising water inside of each chamber lifts a floating ball  160 , closing an opening  161  on the bottom of the plunger, trapping the water inside of the chamber. After a full revolution, the sleeve comes back to pump A. Here, the lower chamber of the pump is full with water. Plunger is empty. 
         [0047]    Step 2 is represented by A 2 : Sleeve is moving again above the plunger of the pump A and supplies an equal amount of water into it. Because at this time both valves, on the top and the bottom of the sealed chamber  164  are closed, sleeve is filling-up the plunger. Weight of the rising water in the plunger is pushing the plunger down, compressing the spring and, therefore the water in the lower sealed chamber  164  of the pump, creating a pressure inside of said chamber. When calculated amount of water is released into the plunger, sleeve move further to pump B (see  FIG. 9 ). 
         [0048]    Step 3 is represented by A 3 : Pressure in the camber  164  securely closes an opening  161  in the bottom of the plunger and opens the normally closed check valve  158  at the bottom of chamber  164 . Full of water plunger is moving more and more down, evacuating water from the chamber. When floating ball  160  is reaching a pin  156 , it changes its own position: the pin is slightly moving the ball and, therefore, opens the hole  161 . Now, when plunger and chamber are communicating, the pressure in both of them equalizes. Decompressed pump is releasing the compressed spring, which lifts the plunger to its original position, check ball  160  falls down, and the moving up plunger is releasing collected in it water into the chamber: water flows downward by gravity. Once again, chamber is full with water and plunger is empty, awaiting for the sleeve to come back above it and supply the same portion of the water. 
         [0049]    The described process of water evacuation constantly repeats itself and, therefore, constantly evacuates water from the bottom of the tank, allowing turbine to rotate. In reality, the number of pumps and sleeves in one apparatus can be much larger, in order to speed up the process of water evacuation from the bottom of the tank. 
         [0050]    It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of methods and constructions differing from the type described above. 
         [0051]    While the invention has been illustrated and described as embodied in a method and an apparatus for generating electrical energy, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. 
         [0052]    Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, be applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.