Gauge for determining the percentage by weight of moisture contained in a bulk material transported on a moving conveyor

Claim 2

A gauge for determining the weight percentage moisture in a bulk substance transported in a longitudinal direction on a moving hydrogenous conveyor having a width perpendicular to the direction of conveyor movement, said gauge comprising: a source of fast neutrons for directing fast neutrons through substantially less than the entire width of said hydrogenous belt and bulk substance transported thereby, a source of gamma radiation for directing gamma radiation through substantially less than the entire width of said hydrogenous belt and bulk substance transported thereby, the energy of said fast neutrons and the belt width irradiated thereby being selected to irradiate a cross-sectional area of said bulk substance substantially equal in cross-sectional area to the cross-sectional area of said bulk material irradiated by said gamma source, a detector for detecting slow neutrons generated in said bulk material and producing a first electrical signal correlated thereto, and for detecting gamma radiation transmitted through said bulk material and generating a second electrical signal correlated thereto, and a signal processing circuit for processing said first and second signals to produce an output related to the weight percentage moisture in said bulk substaNce.

Claim 3

A gauge for determining the weight percentage moisture in a bulk substance transported in a longitudinal direction on a moving hydrogenous conveyor having a width perpendicular to the direction of conveyor movement, said gauge comprising: a source of fast neutrons for directing fast neutrons through said belt and bulk substance transported thereby, a source of gamma radiation for directing gamma radiation through said belt and bulk substance transported thereby, a detector for detecting slow neutrons generated from a first cross-sectional area of said bulk substance and producing a first electrical signal correlated thereto, and for detecting gamma radiation emanating from a second cross-sectional area of said bulk substance and producing a second electrical signal correlated thereto, said first and second cross-sectional areas being substantially equal and being substantially less than the entire cross-sectional area of said bulk substance, and a signal processing circuit for processing said first and second signals to produce an output related to the weight percentage moisture in said bulk substance.

Claim 4

A gauge for determining the weight percentage moisture in a bulk substance transported in a longitudinal direction on a moving hydrogenous conveyor having a width perpendicular to the direction of conveyor movement, said gauge comprising: a source of fast neutrons for directing fast neutrons through said belt and bulk substance transported thereby, a source of gamma radiation for directing gamma radiation through said belt and bulk substance transported thereby, a detector for detecting slow neutrons generated from a first cross-sectional area of said bulk substance and producing a first electrical signal correlated thereto, and for detecting gamma radiation emanating from a second cross-sectional area of said bulk substance and producing a second electrical signal correlated thereto, said first and second cross-sectional areas being substantially equal and being substantially less than the entire cross-sectional area of said bulk substance, and a signal processing circuit for processing said first and second signals to produce an output related to the weight percentage moisture in said bulk substance.

Claim 5

The gauge of claim 2 wherein said gamma and fast neutron sources each irradiate substantially the entire cross-sectional area of said bulk substance, and wherein said detector includes: a. separate slow neutron and gamma detectors, and b. means for permitting said separate slow neutron and gamma detectors to detect slow neutrons and gamma from only said first and second equal cross-sectional areas.

Claim 6

The gauge of claim 1 wherein said bulk substance is wood chips or a material having a density substantially equal thereto; said gamma source includes at least three physically separate gamma-emitting radioactive elements located at first, second and third points spaced along the width of said belt, the distance between the outermost of said elements being substantially less than the width of said belt; and said fast neutron source includes at least two fast-neutron-emitting radioactive elements located along said belt width at fourth and fifth points interspersed between said first, second and third points.

Claim 7

The gauge of claim 1 wherein said bulk substance is sinter mix or a material having a density substantially equal thereto; said gamma source includes at least two physically separate gamma-emitting radioactive elements located at first and second points along said belt width spaced apart substantially less than the width of said belt; and wherein said fast neutron source includes at least one fast neutron-emitting radioactive element located at a point intermediate said first and second points.

Claim 8

The gauge of claim 1 wherein said gamma-emitting source includes radioactive gamma-emitting elements located along the width of said belt exteriorly of said fast neutron source.

Claim 9

A gauge for determining the weight percentage moisture in a bulk substance transported in a longitudinal direction on a moving conveyor having a width perpendicular to the direciton of conveyor movement, said gauge comprising: a source of fast neutrons for directing fast neutrons through said belt and bulk substance transported thereby, a source of gamma radiation for directing gamma radiation through said belt and bulk substance transported thereby, a detector for detecting slow neutrons generated from a first cross-sectional area of said bulk substance and producing a first electrical signal correlated thereto, and for detecting gamma radiation emanating from a second cross-sectional area of said bulk substance and producing a second electrical signal correlated thereto, said first and second cross-sectional areas being substantially equal and being substantially less than the entire cross-sectional area of said bulk substance, a neutron reflector for directing fast neutrons incident thereon back into said bulk substance, said reflected fast neutrons having been, prior to incidence on said reflector, transmitted throUgh said bulk substance, said belt being located between said source and reflector in a range where the said first detector output signal would be substantially constant over small variations in position, relative to said source and detector, were the belt to have a constant weight moisture load thereon, and a signal processing circuit for processing said first and second signals to produce an output related to the weight percentage moisture in said bulk substance.

Claim 10

A gauge for determining the weight percentage moisture in a bulk substance transported in a longitudinal direction on a moving conveyor having a width perpendicular to the direciton of conveyor movement, said gauge comprising: a source of fast neutrons for directing fast neutrons through said belt and bulk substance transported thereby, a source of gamma radiation for directing gamma radiation through said belt and bulk substance transported thereby, a detector for detecting slow neutrons generated from a first cross-sectional area of said bulk substance and producing a first electrical signal correlated thereto, and for detecting gamma radiation emanating from a second cross-sectional area of said bulk substance and producing a second electrical signal correlated thereto, said first and second cross-sectional areas being substantially equal and being substantially less than the entire cross-sectional area of said bulk substance, a neutron reflector for directing fast neutrons incident thereon back into said bulk substance, said reflected fast neutrons having been, prior to incidence on said reflector, transmitted throUgh said bulk substance, said belt being located between said source and reflector in a range where the said first detector output signal would be substantially constant over small variations in position, relative to said source and detector, were the belt to have a constant weight moisture load thereon, and a signal processing circuit for processing said first and second signals to produce an output related to the weight percentage moisture in said bulk substance.

Claim 11

The gauge of claim 2 wherein said first and second cross-sectional areas are located centrally of said belt width.

Claim 12

The gauge of claim 8 wherein said bulk substance has a depth at said central cross-sectional area equivalent to approximately 3 1/2 inches of wood chips at 50 percent by weight of moisture.

Claim 13

The guage of claim 8 wherein said conveyor is supported by first and second rollers located below opposite marginal portions of said belt and a third roller located below a central portion of said belt, said first and second rollers being disposed relative to said third roller at an angle sufficient to produce at said central cross-sectional area a depth of bulk substance equivalent to approximately 3 1/2 inches of wood chips at 50 percent by weight of moisture.

Claim 14

The gauge of claim 1 wherein said equal irradiated cross-sectional areas are between approximately 25 and 75 percent of the entire cross-sectional area of the bulk substance.

Claim 15

The gauge of claim 11 wherein said equal irradiated cross-sectional areas are approximately one-third the entire cross-sectional area of the bulk substance.

Claim 16

The gauge of claim 2 wherein said equal cross-sectional areas are between approximately 25 and 75 percent of the entire cross-sectional area of the bulk substance.

Claim 17

Th gauge of claim 13 wherein said equal cross-sectional areas are approximately one-third the entire cross-sectional area of the bulk substance.

Claim 18

The gauge of claim 1 wherein the weight of moisture in said cross-sectional area is relatively high; said gamma source includes at least three physically separate gamma-emitting radioactive elements located at first, second and third points spaced along the width of said belt, the distance between the outermost of said elements being substantially less than the width of said belt; and said fast neutron source includes at least two fast neutron-emitting radioactive elements located along said belt width at fourth and fifth points interspersed between said first, second and third points.

Claim 19

The gauge of claim 1 wherein the weight of moisture in said cross-sectional area is relatively low; said gamma source includes at least two physically separate gamma-emitting radioactive elements located at first and second points along said belt width spaced apart substantially less than the width of said belt; and wherein said fast neutron source includes at least one fast neutron-emitting radioactive element located at a point intermediate said first and second points.

Claim 20

The gauge of claim 2 wherein the neutron source energy level is selected to produce maximum gauge sensitivity for a predetermined maximum moisture without saturating.

Claim 21

A gauge for determining the weight percentage moisture in a bulk substance transported in a longitudinal direction on a moving conveyor having a width perpendicular to the direction of conveyor movement, said gauge comprising: a source of fast neutrons for directing fast neutrons into said bulk substance transported thereby, a source of gamma radiation for directing gamma radiation into said bulk substance transported thereby, a detector for detecting slow neutrons generated from a first cross-sectional area of said bulk substance and producing a first electrical signal correlated thereto, and for detecting gamma radiation emanating from a second cross-sectional area of said bulk substance and producing a second electrical signal correlated thereto, said firSt and second cross-sectional areas being substantially equal and being substantially less than the entire cross-sectional area of said bulk substance, and a signal processing circuit for processing said first and second signals to produce an output related to the weight percentage moisture in said bulk substance.

Claim 22

A gauge for determining the weight percentage moisture in a bulk substance transported in a longitudinal direction on a moving conveyor having a width perpendicular to the direction of conveyor movement, said gauge comprising: a source of fast neutrons for directing fast neutrons into said bulk substance transported thereby, a source of gamma radiation for directing gamma radiation into said bulk substance transported thereby, a detector for detecting slow neutrons generated from a first cross-sectional area of said bulk substance and producing a first electrical signal correlated thereto, and for detecting gamma radiation emanating from a second cross-sectional area of said bulk substance and producing a second electrical signal correlated thereto, said firSt and second cross-sectional areas being substantially equal and being substantially less than the entire cross-sectional area of said bulk substance, and a signal processing circuit for processing said first and second signals to produce an output related to the weight percentage moisture in said bulk substance.