PROPORTIONING SYSTEM

• US 3,847,809 A
• Filed: 07/03/1972
• Issued: 11/12/1974
• Est. Priority Date: 07/03/1972
• Status: Expired due to Term

• Current Assignee: Kopf J. David
• Original Assignee: Kopf J. David
• Inventors: Kopf, J. David
• Primary Examiner(s): Spear, Jr., Frank A.
• Application Number:
  US05/268,308
• Time in Patent Office: 862 Days
• Field of Search: 210/96,321,22 137/92,563,6H
• US Class Current: 210/647
• CPC Class Codes: A61M 1/1656 Apparatus for preparing dialysates
• CPC Class Codes: A61M 1/1658 Degasification
• CPC Class Codes: A61M 1/1668 Details of containers
• CPC Class Codes: B01F 23/40 Mixing liquids with liquids; Emulsifying
• CPC Class Codes: B01F 35/82 by adding a material to be mixed to a mixture in response to a detected feature, e.g. density, radioactivity, consumed power or colour
• CPC Class Codes: G05B 11/00 Automatic controllers G05B13/00 takes precedence
• CPC Class Codes: G05D 21/02 characterised by the use of electric means

Abstract

A proportioning device and method for mixing two fluids in predetermined proportions. A portion of one fluid flowing through a first flow path is discharged into a second fluid flowing at different flow rates through a second flow path, creating a mixture of the two fluids. The proportions of the two fluids in the mixture are measured, and in response to this measurement, the discharge rate of the first fluid into the second fluid is adjusted to maintain the desired mix ratio.

Claims

1. A METHOD FOR USING IN HEMODIALYSIS OF FORMING A DIALYSATE BY MIXING PREDETERMINED AMOUNTS OF A FLUID IN A FLOW STREAM AND MAINTAINING THE RATIO OF FLUID IN SAID FLOW STREAM FOR VARIOUS FLOW RATES, COMPRISING THE FOLLOWING STEPS:

CONSTANTLY RECIRCULATING A FIRST FLUID ALONG A FIRST FLOW STREAM, PASSING A SECOND FLUID THROUGH A CONDUIT TO FORM A SECOND FLOW STREAM, DIVERTING A REGULATED AMOUNG OF SAID CONSTANTLY RECIRCULATING FIRST FLUID AT A PRESELECTED DISCHARGE POINT AND DISCHARGING THE SAME INTO SAID SSECOND FLOW STREAM AT SAID DISCHARGING POINT WHILE MAINTAINING THE CONSTANT RECIRCULATION OF THE REMAINDER OF SAID FIRST FLUID IN SAID FIRST FLOW STREAM, ALLOWING SAID FIRST AND SECOND FLUIDS TO MIX, MEASURING THE PROPORTIONS OF SAID FIRST FLUID AND SAID SECOND FLOW STREAM AT A POINT DOWNWARD FROM WHICH THE FLUIDS HAVE BEEN MIXED, AND ADJUSTING THE RATE AT WHICH SAID FIRST FLUID IS DISCHARGED INTO SAID SECOND FLOW STREAM.

2. A method for use in hemodialysis of forming a dialysate by mixing predetermined amounts of first and second fluids in a flow stream and maintaining the ratio of the fluids in said flow stream for various flow rates, comprising the following steps:

continuously passing a first fluid through a first conduit under pressure, passing a second fluid through a second conduit under pressure less than that in said first conduit, diverting a regulated amount of said constantly passing first fluid at a preselected discharge point and discharging the same from said first conduit into said second conduit at said discharge point while maintaining the constant passing of said first fluid through said first conduit, allowing said first and second fluids to mix in a flow stream through said second conduit, measuring the proportion of said first fluid in the flow stream at a point downstream from where the fluids have mixed, and adjusting the rate at which said first fluid is discharged into said second conduit to maintain a predetermined proportion of said first fluid in the flow stream.

3. A method for use in hemodialysis of forming a dialysate by mixing two fluids in predetermined and controlled proportions comprising the following steps:

continuously recirculating a first fluid through a first flow path, passing a second fluid through a second flow path which intersects said first flow path, diverting a regulated amount of said constantly recirculating first fluid at said intersection and discharging the same into said second flow path at said intersection while maintaining the continuous recirculation of the remainder of said first fluid in said first flow path, measuring the proportions of said first and second fluids in said second flow path downstream of said intersection, and controlling the rate at which said first fluid is discharged into said second flow path in response to said measuring, by increasing the discharge rate of said first fluid when the proportion of said first fluid is too low, and decreasing the discharge rate of said first fluid when the proportion of said first fluid is too high.

4. A method for continuously mixing, in predetermined portions, concentrate solution and water for use in kidney dialysis comprising the following steps:

continuously circulating the concentrate solution at a regulated pressure through a first flow path, passing water through a second flow path, diverting a regulated amount of said constantly circulating concentrate solution at a preselected discharge point and discharging the same into said second flow path while maintaining the constant circulation of the remainder of said concentrate solution if said first flow path, thereby forming a mixture of concentrate solution and water, continuously measuring the electrical conductivity of said mixture, and by using the electrical conductivity of said mixture as an indication of the proportions of concentrate solution and water, and continuously controlling the rate at which the concentrate solution discharges into said water by regulating the pressurE of the circulating concentrate solution in response to said continuous measuring of conductivity, increasing said pressure when said conductivity is too low, and decreasing said pressure when said conductivity is too high.

5. The method of claim 4 wherein said first and second flow paths intersect.

6. In an artificial kidney machine, a proportioning device for mixing two fluids in predetermined proportions comprising:

a first conduit through which a first fluid constantly recirculates, a second conduit through which a second fluid flows, an orifice in the surface of said first conduit through which a portion of said first fluid is discharged into said second conduit while maintaining the constant recirculation of the remainder of the said first fluid through said first conduit, said portion of said first fluid forming a mixture with said second fluid, measuring means for measuring the proportions of said first and second fluids in said mixture, and control means cooperating with said measuring means for controlling the rate at which said first fluid escapes through said orifice, thereby maintaining the desired proportions of said first and second fluids in said mixture.

7. The device of claim 6 wherein said control means includes an electronic servo control responding to said measuring means and pressure regulated means for regulating the pressure of said first fluid in the vicinity of said orifice in response to said electronic servo control, increasing said pressure when the proportion of said first fluid in said mixture is too low and decreasing said pressure when the proportion of said fluid in said mixture is too high, said pressure regulating means having a motor, a variable speed pump driven by said motor, and a restriction in said first conduit downstream of said orifice.

8. The device of claim 7 wherein said pressure regulating means comprises a constant speed pump and a variable restriction in said first conduit downstream of said orifice, said variable restriction being controlled by said electronic servo control.

9. For use in an artificial kidney machine, a proportioning device for continuously mixing concentrate and water in predetermined proportions comprising:

a first conduit through which concentrate flows at a controlled pressure, a second conduit through which water flows, the surface of said first conduit having an orifice through which a portion of said concentrate flowing through said first conduit is discharged into said second conduit at a mixing point with the remainder of said concentrate continuing to flow in said first conduit past said orifice, and control means cooperating with said measuring means for controlling the rate at which concentrate passes through said orifice, thereby maintaining the desired mix proportions of water and concentrate.

10. The device of claim 9 wherein said second conduit intersects said first conduit at the location of said orifice and wherein said control means maintains a pressure drop across said orifice, the pressure of said concentrate in said first conduit being greater than the pressure of said water in said second conduit near said orifice.

11. The device of claim 9 wherein the cross-sectional area of said first conduit at the location of said orifice is at least five times greater than the cross-sectional area of said orifice.

12. The device of claim 9 further comprising blending means having a plurality of sharp bends in said second conduit, said blending means blending the concentrate and water mixture in said second conduit immediately downstream of said orifice.