Abstract:
A machine for and method of exploiting diffusion and osmotic pressure to generate linear motion in a fluid and derive energy from it.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims benefit of U.S. Provisional Patent Application Ser. No. 60/572,062 filed May 18, 2004. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not Applicable  
       DESCRIPTION OF ATTACHED APPENDIX  
       [0003]     Not Applicable  
       BACKGROUND OF THE INVENTION  
       [0004]     1. Field of Invention  
         [0005]     This invention relates generally to the fields of chemistry and fluid flow mechanics and more specifically to a machine and method to derive energy through diffusion and/or osmotic pressure.  
         [0006]     2. History  
         [0007]     Certain previously known technology such as by Jellinek (U.S. Pat. No. 3,978,344) and Weingarten (U.S. Pat. No. 3,587,227) that exploit osmotic pressure as an energy source require constant feed sources of fresh and saline water, or, more generally solute and solvent replenishment. They make no provision for reconditioning their working fluids for re-use, and therefore must be located near virtually inexhaustible sources of fresh and saline water or other solvent and solute.  
         [0008]     Another previously known osmosis energy generation technology by Loeb (U.S. Pat. No. 4,193,267) uses a heat engine model, requiring a heat source and/or a heat sink and significant hydraulic pressures and pressure differentials to operate.  
       OBJECT OF INVENTION  
       [0009]     One object of this invention is to generate and extract energy using physical and chemical properties of diffusion and osmosis.  
         [0010]     Another object of this invention is to generate and extract energy using physical and chemical properties of diffusion and osmosis while avoiding the need for fresh solvent, solute, or solution replenishment external to the system.  
         [0011]     Another object of this invention is to accomplish energy extraction from diffusion and osmotic pressure at near ambient atmospheric temperatures and pressures.  
         [0012]     Other objects and advantages of the present invention will become apparent from the following descriptions, taken in connection with the accompanying drawings, wherein, by way of illustration and example, embodiments of the present invention are disclosed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.  
         [0014]      FIG. 1  is a cross sectional view of the invention, in a preferred mode, with the top open.  
         [0015]      FIG. 2  is a cross sectional view of the invention, in an alternate preferred mode, with the top portion closed to the external atmosphere. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     List of Parts  
       [0016]     Downward inlet portion affixed with a semi-permeable membrane  10   
         [0017]     Submerged portion of solution container  15   
         [0018]     Inlet semi-permeable membrane  20   
         [0019]     Closed sump  30   
         [0020]     Essentially pure sump solvent  40   
         [0021]     Downward outlet portion equipped with semi-permeable membrane  50   
         [0022]     Outlet semi-permeable membrane  60   
         [0023]     Third portion  70   
         [0024]     Solution of solvent and solute (water and starch)  80   
         [0025]     Re-purified solvent  85   
         [0026]     Paddle wheel  90   
         [0027]     Turbine  95   
         [0028]     Inverted “Y”-shaped solution container  100   
         [0029]     Vent Opening  110   
         [0030]     Vent Seal  120   
         [0031]     Agitator  130   
         [0032]     Servo unit  135   
         [0033]     Inward flow of solvent  140   
         [0034]     Outward flow of solvent  145   
         [0035]     Intersection point  155   
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0036]     Detailed descriptions of the preferred embodiment are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner.  
         [0037]     This invention is based on a process of diffusion and osmotic pressure and a means of drawing energy from fluid flow generated by them. Diffusion is the movement of chemicals in a system that is not in equilibrium (i.e. a system that has a chemical gradient) as they seek to establish equilibrium. These chemicals must either be gaseous, or in solution, and either have no attraction toward their own kind, or attraction to each other greater than to their own kind, otherwise the chemicals will remain separate, like oil and water. Osmosis is a particular type of diffusion that specifically describes solvent diffusing across a semi-permeable membrane to establish equilibrium.  
         [0038]     In the herein taught technology, the forces of diffusion and osmosis are harnessed via semi-permeable membranes. A semi-permeable membrane is a membrane that allows some molecules to pass through it, but will not allow others to pass through it. What will or will not pass may be determined or effected by molecule size, electrical charge, or some other factor.  
         [0039]     An example of this phenomenon may be found in the walls of living cells. The cell wall is a semi-permeable membrane that will allow solvent (water) but not solute (salt) to pass through. This phenomenon explains why when a living cell is placed in a solution containing a higher concentration of salt than the cell itself, the cell will shrivel and shrink (hypertension) as the rate of water leaving the cell exceeds the rate of water entering the cell until equilibrium is established.  
         [0040]     Conversely, if the solution has a lower concentration of salt, the cell will swell (become turgid) as the rate of water entering exceeds the rate of water exiting. If the salt in surrounding solution were of sufficiently low concentration, the cell would ultimately explode as the external and internal solutions would never reach equilibrium.  
         [0041]     Osmotic pressure can be created through this phenomenon by exploiting the affinity of strong solutions to establish equilibrium with weak solutions across a semi-permeable membrane. The degree of osmotic pressure created is affected by, among other things, the concentration of the solution, the type of chemical(s) used, the molecular weights, the vapor pressure over the column, and the type of membrane(s) used. This osmotic pressure is here used to draw a column of water solvent up a tube, against the force of gravity, thereby creating potential energy which is then extracted by letting the water pour downward over the blades of a turbine.  
         [0042]     In the process, and before the energy is extracted, the solvent is, by intervention of an outlet permeable membrane, reconditioned for recirculation. The system, as taught herein, requires no external heat source, external heat sink, external solvent source, external solute source, or external solution source.  
       DETAILED DESCRIPTION  
       [0043]     Referring to  FIG. 1 , in one preferred mode, this invention comprises a, generally, upside down, “Y”-shaped solution container ( 100 ). The “Y”-shaped solution container ( 100 ) has an inlet semi-permeable membrane ( 20 ) incorporated into one portion which is submerged ( 15 ) in a sump ( 30 ) containing a solvent ( 40 ) comprising essentially pure water.  
         [0044]     Within or on a downward outlet portion ( 50 ) is placed an outlet semipermeable membrane ( 60 ) that has a higher affinity for water than does the inlet semi-permeable membrane ( 20 ) that covers the inlet submerged portion ( 15 ). This downward outlet portion ( 50 ) of the “Y” is so positioned that any liquid flowing from it ( 85 ) will ultimately flow back into the same sump ( 30 ) in which the inlet portion ( 15 ) is submerged, and from which the solvent water ( 40 ) is drawn.  
         [0045]     The third portion ( 70 ) pointing upward is left open to atmosphere. This configuration feature tends to prevent gas pressure build up in the top of the solution container.  
         [0046]     The inlet downward portion ( 10 ) and submerged portion ( 15 ) is filled with a solution of water solvent and starch solute ( 80 ). The starch molecules in this solution will not pass through either the inlet ( 20 ) or outlet ( 60 ) semi-permeable membrane, but water solvent ( 40 ) can pass, and will be drawn up from the sump ( 30 ) into the solution container ( 100 ) by the action of diffusion.  
         [0047]     In this configuration, essentially pure water solvent ( 40 ) from the sump ( 30 ) is drawn by the starch and water solution ( 80 ) up into the submerged portion ( 15 ), passing through the submerged semi-permeable membrane ( 20 ). As the water solvent ( 40 ) is drawn upward, it fills up through the inlet portion ( 10 ), until it overflows at the intersection point ( 155 ) of the outlet downward portion ( 50 ) of the “Y,” where it encounters the outlet semi-permeable membrane ( 60 ).  
         [0048]     Since this outlet membrane ( 60 ) will not permit the starch solute molecules to pass, but will allow water solvent to pass and has a higher affinity for water than does the inlet membrane ( 20 ), gravity, diffusion, and osmotic pressure impel the water solvent to separate from the solution ( 80 ) out through the outlet membrane ( 60 ). This leaves the starch solute behind in the solution ( 80 ). The re-purified water solvent ( 85 ) pours back into the sump ( 30 ) from whence it came, mixing with the solvent water ( 40 ) in the sump ( 30 ) and the cycle repeats.  
         [0049]     Referring now to  FIG. 1  and  FIG. 2 , mechanical energy may be drawn from the inlet flow ( 140 ) of the water solvent as it enters the inlet portion ( 10 ), flows through the solution container ( 100 ), or flows out of the outlet portion ( 50 ). For, example, a small turbine or paddle wheel ( 90 ), as in  FIG. 1 , may be placed in or below the flow such that the falling liquid causes it to spin, or, it may be situated in the midst of the solution container ( 100 ), as in  FIG. 2 , such that flow through the container ( 100 ) will move the blades of the turbine ( 95 ).  
         [0050]     Referring, now, to  FIG. 1 , with the top of the container open ( 110 ), the level of the solvent column will rise as solvent is drawn in through the inlet semi-permeable membrane ( 20 ). The column will continue to rise until equilibrium is achieved between the inward flow of solvent ( 140 ) through the inlet semi-permeable membrane ( 20 ), and the outward flow of solvent through the outlet semi-permeable membrane ( 60 ). This outward flow ( 145 ) is impelled both by gravity and by the pressure head created by the solution column in the solution container ( 100 ).  
         [0051]     In such a configuration, the flow rate may be conveniently varied by adjusting the height of the outlet membrane ( 60 ) relative to the solution column. The lower the outlet membrane ( 60 ) is, relative to the solution column, the higher the eventual pressure head, and the higher the equilibrium flow rate. This is also particularly convenient for adjusting the system in response to variations in performance due to changes in solution concentrate, ambient pressure, or temperature, or due to changes in, or degradation of, the semi-permeable membranes ( 60 ) and ( 20 ). Under such circumstances, should the system flow experience excursions outside nominal parameters, the outlet membrane ( 60 ) location may be adjusted upward or downward to return flow to the preferred rate.  
         [0052]     Referring to  FIG. 2 , in an alternative mode, the vent opening ( 110 ) may be closed or be covered with a seal ( 120 ) thus forestalling evaporation, but making the system more subject to vapor or fluid pressure build-up above the liquid column. At the same time, however, removing the gases and closing off the vent opening ( 110 ) allows the interior osmotic pressure to more compactly assist in forcing solvent through the outlet semi-permeable membrane and out of the solvent container.  
         [0053]     Referring again to  FIG. 1 , an agitator ( 130 ) may be introduced that preferably draws its energy from the fluid flow. The purpose of this agitator ( 130 ) is to assist in maintaining homogeneity of the solution ( 80 ). In this depiction, an agitator ( 130 ), resembling a pin-wheel, is linked to the power turbine ( 90 ) by a simple servo mechanism ( 135 ).  
         [0054]     Once the unit begins operation, fluid flow ( 140 ) and ( 145 ) increases until a state of flow and pressure equilibrium are reached between the inlet membrane ( 20 ) and the outlet membrane ( 60 ), and continues until one or both membranes become so degraded as to no longer support the necessary diffusion and osmotic action. The system as taught herein requires no heat source, heat sink, external solvent source or external solute source.  
         [0055]     While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.