Method and apparatus for determining the heat content of gaseous fuels

Claim 2

Apparatus for determining the heating value of gaseous fuels comprising: means for establishing a mixture of a gaseous fuel, the heat content of which is sought to be determined, and air of known volumetric proportions; means for causing the oxidation of said fuel in said mixture of known proportions; sensing means for sensing the presence of combustibles or oxygen in the products of oxidation of said mixture, said sensing means having an output quantitatively indicative of said combustibles or oxygen in said products of oxidation and wherein said sensing means exhibits a high sensitivity in the form of a rapid change in output about a particular combustible/oxygen percentage composition; means for adjusting the proportions of fuel and air in said mixture in response to the output of said sensing means until said sensing means indicates that said mixture of known proportions produces oxidation products substantially at said percentage composition of high sensor sensitivity. means for determining the heating value of said fuel from a known relationship between the heating value of the fuel constituents and the amount of oxygen required to produce oxidation products at said percentage composition of high sensor sensitivity.

Claim 3

The apparatus fo claim 1 wherein said means for establishing said gaseous fuel and air mixture of known volumetric proportions further comprises: a rotary proportioning system including: first inlet means adapted to be connected to a source of said fuel; second inelt means adapted to be connected to a source of said air; first outlet means for discharging an effluent mixture; second outlet means for discharging said mixture of interest; rotatable member, said rotatable member being provided with a plurality of fixed hollow volumes having open accesses at the extremes thereof such that upon rotation of said rotatable member each of said volumes is sequentially connected between said first inlet and said first outlet and said second inlet and said second outlet; means for rotating said rotatable member.

Claim 4

The apparatus of claim 2 wherein said rotatable member further comprises; a cylinder provided with a series of spaced radially distributed cylindrical holes therethrough forming an annular pattern; and wherein said apparatus further comprises: first non-rotating member for containing said first and said second inlet means; wherein said first inlet means further comprises a partially annular first inlet groove in said non-rotating member juxtaposed to and communicating with the inlet accesses of the holes in said rotatable member located opposite said groove; and wherein said second inlet means further comprises a partially annular second inlet groove in said non-rotating member spaced from said first groove and relatively longer than said first groove also being juxtaposed to an ion communication with the inlet accesses of said holes in said rotatable member located opposite said second groove; and second non-rotating member containing said first and second oulet means comprising counterpart first and second outlet grooves symmetrical to and aligned with said first and second inlet grooves, said outlet grooves being juxtaposed to and in communication with the outlet accesses of said holes in said rotatable member opposite them; and wherein said first and second inlet grooves further respectively are in communication with said source of fuel and said source of air; and wherein said first outlet goove is in communication with an effluent conduct means and said second outlet groove is in communication with a conduit means for conveying the mixture of interest.

Claim 5

The apparatus of claim 3 wherein the inlet and outlet connections to said sources of fuel and air and the outlet connections to said conduit for said effluent and said mixture of interest comprise openings communicating with said grooves and wherein the corresponding openings communicating with said respective inlet and outlet grooves are located at opposite extremes of said grooves such that the contents of each groove also tends to flow along the groove in traversing the system.

Claim 6

The apparatus of claim 4 wherein the disposition of said inlet and outlet openings accessing said grooves relative to the direction of rotation of said rotatable member is such that the fuel tends to flow along the inlet groove in a direction opposite to the rotation of the rotatable member and the air tends to flow in the same direction as the rotation of the rotatable member.

Claim 7

The apparatus of claim 2 wherein said rotatable member further comprises; a cylinder provided with dual inner and outer series of spaced radially distributed holes forming a symmetrical pattern such that each inner hole is paired with a corresponding outer hole and hollow grooves connecting the bottoms of the holes in each pair forming U-tubes thereby; and wherein said apparatus further comprises: a non-rotating member further comprising: inner and outer pairs of parallel fixed partially annular grooves juxtaposed to and aligned with said inner and outer series of holes, each of said pairs of grooves comprising a shorter and a longer grooves spaced apart and wherein the two shorter and two longer grooves are in radial alignment; wherein one of said shorter grooves connects to said source of fuel and the other of said shorter grooves connects to an effluent outlet; and wherein one of said longer grooves is connected with said source of air and the other of said longer grooves is connected with an outlet for said mixture of interest.

Claim 8

The apparatus of claim 6 wherein the inlet and outlet accesses to said grooves comprise openings at the opposite radial extremes thereof such that the contents flowing therethrough tend to flow along each respective groove in moving from inlet to outlet.

Claim 9

The apparatus of claim 7 wherein the disposition of said inlet and outlet openings accessing said grooves relative to the direction of rotation of said rotatable member is such that the fuel tends to flow along the inlet groove in a direction opposite to the rotation of the rotatable member and the air flow tends to be in the same direction as the rotation of the rotatable member.

Claim 11

The apparatus of claim 9 further comprising means for controlling and varying the speed of said motor.

Claim 14

The apparatus of claim 1 wherein said means for establishing said mixture of known volumetric proportions further comprises: a plurality of valves assembled in at least two ordered pairs each pair having a first and a second valve; a member of known volume separating the valves in each pair; means for supplying fuel gas to an inlet port of each of said first valves; means for supplying air to an inlet port of each of said first valves; means for connecting an exit port of each of said second valves to an effluent means; means connecting an exit port of each of said second valves to said means for causing the oxidation of said fuel; means for alternately positioning said ports of said valves between two positions such that in a first position air is caused to flow through the first ordered pair into said oxidizing means and fuel is caused to flow through said second ordered pair to said effluent and in a second position wherein fuel is caused to flow through said second ordered pair to said effluent, and said air is caused to flow through said first ordered pair to said oxidizing means.

Claim 15

The apparatus of claim 13 further comprising a mixing chamber between said valves and said burner.

Claim 16

The apparatus of claim 13 wherein said valves are poppet valves.

Claim 17

The apparatus of claim 1 wherein said sensing means further comprises a substantially solid state electrochemical cell.

Claim 18

The apparatus of claim 16 wherein the electrical output of said sensing cell undergoes a step change as the amount of oxygen sensed approaches zero.

Claim 19

The apparatus of claim 16 wherein said electrochemical cell is one made substantially of ZrO 2 stabilized by a compound substantially consisting of one or more of the following, CaO, MgO, and Y 2 O 3 .

Claim 20

The apparatus of claim 18 wherein said stabilizing compound consists substantially of CaO.

Claim 21

The apparatus of claim 1 further comprising means for regulating the flow of said fuel gas and said air entering the system.

Claim 22

The apparatus of claim 1 further comprising calibration means for calibrating said known relationship between said heating value and said stoichiometric amount of oxygen.

Claim 23

The apparatus of claim 1 wherein said means for causing the oxidation of said fuel is a burner.

Claim 26

The method according to claim 23 wherein said solid state electrochemical sensor exhibits a high sensitivity when said proportions of fuel and air in the mixture are substantially stoichometric.

Claim 27

The method according to claim 24 wherein said solid state electrochemical sensor is one made substantially of ZrO 2 stabilized by a compound substantially consisting of one or more compounds selected from the group consisting of CaO, MgO, and Y 2 O 3 .

Claim 28

The method according to claim 25 wherein said stabilizing compound consisting substantially of CaO.