Closely coupled, dual turbine volumetric flow meter

A volumetric fluid flow meter for measuring flow in a conduit, which comprises:

• a first bi-directional, substantially non-magnetic, independent turbine assembly, said turbine assembly having a vane assembly and a turbine having a plurality of substantially magnetic rotors, said turbine adapted to freely rotate at speeds representative of differing rates of fluid flow past said first turbine assembly;
• a second bi-directional, substantially non-magnetic, independent turbine assembly, said turbine assembly having a vane assembly and a turbine having a plurality of substantially magnetic rotors, said turbine adapted to freely rotate at speeds representative of differing rates of fluid flow past said second turbine assembly;
• a flow randomizer located between said first bi-directional turbine assembly and said second bi-directional turbine assembly, said randomizer having a plurality of vanes of sufficient length to eliminate substantially all flow effects of one of said turbine assemblies upon the other turbine assembly;
• a first magnetic pickup located adjacent said magnetic rotors of said first turbine assembly for transducing the speed of rotation of said first turbine;
• a second magnetic pickup located adjacent said magnetic rotors of said second turbine assembly for transducing the speed of rotation of said second turbine;
• and
• wherein an overall length of said flow meter is equal to or less than 3 times an inside diameter of said flow meter.

A volumetric fluid flow meter which comprises:

• a first independent cantilevered turbine assembly, said turbine assembly having a vane assembly and a turbine having a plurality of rotors, said turbine adapted to freely rotate at speeds representative of differing rates of fluid flow past said first turbine assembly;
• a second independent cantilevered turbine assembly, said turbine assembly having a vane assembly and a turbine having a plurality of rotors, said turbine adapted to freely rotate at speeds representative of differing rates of fluid flow past said second turbine assembly;
• a flow randomizer located between said first turbine assembly and said second turbine assembly, said randomizer having a plurality of vanes of sufficient length to eliminate substantially all flow effects of one of said turbine assemblies upon the other turbine assembly;
• a first magnetic pickup located adjacent said magnetic rotors of said first turbine assembly for transducing the Speed of rotation of said first turbine;
• and
• a second magnetic pickup located adjacent said magnetic rotors of said second turbine assembly for transducing the speed of rotation of said second turbine;
• and
• wherein an overall length of said flow meter is equal to or less than 3 times an inside diameter of said flow meter.

A method of measuring the volumetric flow rate of a fluid in a conduit comprising the steps of:

• flowing said fluid through a flow meter of a length approximately equal to or less than three times the nominal diameter of said conduit, said flow meter comprising a first independent turbine assembly and a second independent turbine assembly separated by a flow randomizer having at least one vane, said randomizer spaced from said first turbine assembly a distance equal to between approximately 5 and approximately 10 times a thickness of said vane;
• decreasing flow effects in said fluid caused by said first turbine assembly;
• measuring a speed of rotation of said first independent turbine assembly;
• and
• measuring a speed of rotation of said second independent turbine assembly.

A meter for measuring a volumetric flow of a fluid in a conduit, which comprises:

• a first independent cantilever turbine assembly having a fixed end and a free end;
• a second independent cantilever turbine assembly having a fixed end and a free end;
• said first and second turbine assembly each having a plurality of rotor blades and each adapted to have a speed of rotation representative of the volumetric fluid flow;
• and
• a flow randomizer intermediate said first and second turbine assembly, said randomizer having a first end and a second end and at least one vane, said first end of said randomizer adapted to shroud at least a portion of said free end of said first turbine assembly;
• said second end of said randomizer adapted to shroud at least a portion of said free end of said second turbine assembly, said flow randomizer vane spaced from said rotor blades of said first and second turbine assembly by a predetermined distance.

A meter for measuring a volumetric flow of a fluid in a conduit, which comprises:

• a first independent turbine assembly;
• a second independent turbine assembly;
• said first and second turbine assembly each having a plurality of rotor blades and each adapted to freely rotate at a speed representative of the volumetric fluid flow;
• a flow randomizer intermediate said first and second turbine assembly, said flow randomizer spaced from said rotor blades of said first turbine assembly a distance substantially equal to a distance at which a flow shear layer caused by said randomizer converges for a predetermined fluid flow.

A volumetric fluid flow meter, which comprises:

• a first bi-directional, substantially non-magnetic turbine assembly, said turbine assembly having a vane assembly and a turbine having a plurality of substantially magnetic rotors, said turbine adapted to rotate at speeds representative of differing rates of fluid flow past said first turbine assembly;
• a second bi-directional, substantially non-magnetic turbine assembly, said turbine assembly having a vane assembly and a turbine having a plurality of substantially magnetic rotors, said turbine adapted to rotate at speeds representative of differing rates of fluid flow past said second turbine assembly;
• a flow randomizer located between said first bi-directional turbine assembly and said second bi-directional turbine assembly, said randomizer having a plurality of vanes emanating radially from a central diffuser of sufficient length to eliminate substantially all flow effects of one of said turbine assemblies upon the other turbine assembly, said randomizer spaced from a plane formed by leading edges of one of said turbine assemblies a distance of about 6 to 8 times an average randomizer vane thickness;
• a first magnetic pickup located adjacent said magnetic rotors of said first turbine assembly for transducing the speed of rotation of said first turbine;
• and
• a second magnetic pickup located adjacent said magnetic rotors of said second turbine assembly for transducing the speed of rotation of said second turbine.