Burner controlling apparatus and method

Claim 2

A controlled burner having a combustion air stream and first and second burner fuel streams passing into the burner and a combustion gas stream discharging from said burner, comprising: first means for measuring the flow rate and pressure of the first fuel stream and delivering a signal Q representative of the larger of said measurements; second means for controlling the flow rate of the first fuel stream at a preselected value in response to said signal Q; third means for measuring the temperature of the combustion gas stream; fourth means for measuring the flow rate of the second fuel stream; fifth means for controlling the flow rate of the second fuel stream relative and in response to the temperature of said combustion gas stream; sixth means for measuring the flow rate of the air stream; and seventh means for controlling the flow rate of the air stream relative to the flow rates of the first and second fuel streams into the burner.

Claim 3

An apparatus, as set forth in claim 1, wherein the third, fourth, and fifth means comprises: a temperature measuring element associated with the combustion gases of the burner for measuring the temperature of said gases; a temperature controller connected to the temperature measuring element for delivering a signal H representative of the difference in the measured temperature in a preselected temperature range; a second flow rate measuring element associated with the second fuel stream; a second flow rate transmitter connected to said second flow rate measuring element for delivering a signal D representative of the differential pressure of the second fuel stream; a second computing relay being connected to said flow transmitter for receiving the signal D, extracting the square root thereof and delivering a signal E representative of the volumetric flow rate of the second fuel stream; a flow controller connected to the second computing relay and the temperature controller for receiving signals E and H, comparing said signals E and H, and delivering a signal F representative of the difference between said signals; and a control valve associated with the second fuel stream and connected to the flow controller for receiving the signal F and controlling the flow rate of the second fuel stream in response to said signal F.

Claim 4

delivering a signal C representative of the flow rate of the first fuel stream;

Claim 5

delivering a signal C representative of the flow rate of the first fuel stream;

Claim 6

comparing signal C to a set point B;

Claim 7

comparing signal C to a set point B;

Claim 8

An apparatus, as set forth in claim 1, wherein the first and second means comprises: a first flow measuring element in the first fuel stream; a flow rate transmitter connected to the flow measuring element for delivering a signal a representative of the flow rate of the first fuel stream; a first computing relay connected to the flow rate transmitter for receiving the signal A, computing the square root of signal A and delivering a signal C representative thereof; a flow controller having a set point B and being connected to the first computing relay for receiving the signal C comparing said signal C to the set point B and delivering a first control signal representative of the difference between the flow rate of the first fuel stream and the set point B; a pressure measuring element associated with the first fuel stream; a pressure transmitter connected to the pressure meaSuring element for delivering a signal P representative of the pressure of the first fuel stream; a pressure controller having a set point T and being connected to the pressure transmitter for receiving signal P therefrom, comparing said signal P to said set point T and delivering a second control signal responsive to said comparison; a high-select relay connected to the pressure controller and the first flow controller for receiving first and second control signals, comparing said signals one to the other, and delivering a signal Q representative of the larger of said first and second control signals; a by-pass conduit associated with the first fuel stream; and a control valve positioned in the by-pass conduit and connected to the high-select relay for receiving the signal Q and controlling the flow rate and pressure of the first fuel stream in response to said signal Q.

Claim 9

An apparatus, as set forth in claim 3, wherein the set point B of the flow controller is a variable set point.

Claim 10

delivering a first control signal responsive to the difference between the signal C and the set point B;

Claim 11

delivering a first control signal responsive to the difference between the signal C and the set point B;

Claim 12

measuring the flow rate of the second fuel stream passing to the burner;

Claim 13

measuring the flow rate of the second fuel stream passing to the burner;

Claim 14

An apparatus, as set forth in claim 1, wherein the sixth and seventh means comprises: a third flow rate measuring element associated with the air stream; a third flow rate transmitter connected to said flow measuring element for delivering a signal representative of the differential pressure of said air stream; a third computing relay connected to the third flow rate transmitter for receiving the signal therefrom, extracting the square root of said received signal and delivering a signal J in response thereto; a fourth computing relay being connected to the fifth means for receiving a signal E from the fifth means representative of the volumetric flow rate of the second fuel stream, multiplying said signal E by a set point K, and delivering a signal KE representative of the resultant product; a fifth computing relay having a set point R and being connected to the first means and the fourth computing relay for receiving a signal C from the first means representative of the flow rate of the first fuel stream, adding signal A to the signal KE, multiplying the resultant sum times the set point R, and delivering a signal M representative of the computation; a flow controller connected to the third and fifth computing relays for receiving signals J and M, comparing said signals one to the other, and delivering a signal N responsive to the difference between said signals J and M; a second high-select relay connected to the flow controller for receiving signal N, comparing said signal with a set point D, and delivering the larger of said signal N and set point D; and a controlling valve associated with the air stream and being connected to the second high-select relay for receiving the signal therefrom and controlling the flow rate of the air stream in response thereto.

Claim 15

An apparatus, as set forth in claim 5, wherein the set point K is a variable set point.

Claim 16

delivering a signal E representative of the flow rate of the second fuel stream;

Claim 17

delivering a signal E representative of the flow rate of the second fuel stream;

Claim 18

measuring the temperature of the combustion gases of the burner;

Claim 19

measuring the temperature of the combustion gases of the burner;

Claim 22

delivering a signal representative of the temperature of the combustion gases;

Claim 23

delivering a signal representative of the temperature of the combustion gases;

Claim 24

A method, as set forth in claim 7, including adjusting the constant K for changing the relative flow rate of the air stream.

Claim 25

A method, as set forth in claim 7, including maintaining the temperature of the exhaust gases at temperatures greater than about 1600*F.

Claim 26

comparing the signal of step (8) to a set point B;

Claim 27

comparing the signal of step (8) to a set point B;

Claim 28

delivering a signal H responsive to the difference between the comparison of signals in step (9);

Claim 29

delivering a signal H responsive to the difference between the comparison of signals in step (9);

Claim 30

A method, as set forth in claim 7, including measuring the pressure of the first fuel stream passing to the burner; delivering a signal P representative of the pressure of the first fuel stream; comparing signal P to a set point T; delivering a second control signal responsive to the comparison of signal P and the set point T; comparing the first and second control signals one to the other; and delivering a signal Q representative of the larger of said first and second control signals; and removing at least a portion of the first fuel stream in response to the value of the signal Q.

Claim 31

comparing signal E to a set point H;

Claim 32

comparing signal E to a set point H;

Claim 33

A method, as set forth in claim 10, including adjusting the set point signal B for changing the flow rate of the first fuel stream into the burner.

Claim 34

delivering a signal F responsive to the difference between the signal E and the set point H;

Claim 35

delivering a signal F responsive to the difference between the signal E and the set point H;

Claim 36

controlling the flow rate of the second fuel stream in response to signal F;

Claim 37

controlling the flow rate of the second fuel stream in response to signal F;

Claim 38

measuring the flow rate of the air stream passing to the burner;

Claim 39

measuring the flow rate of the air stream passing to the burner;

Claim 40

delivering a signal J representative of the flow rate of the air stream;

Claim 41

delivering a signal J representative of the flow rate of the air stream;

Claim 42

multiplying signal E times a constant K;

Claim 43

multiplying signal E times a constant K;

Claim 44

adding signal C to the product of step (16);

Claim 45

adding signal C to the product of step (16);

Claim 46

multiplying the sum of step (17) by a constant R; and

Claim 47

multiplying the sum of step (17) by a constant R; and

Claim 48

delivering a signal M responsive to the computation of step (18); comparing signals J and M; delivering a signal N responsive to the difference between signals J and M; comparing signal N with a set point signal O; and controlling the flow rate of the air stream in response to the greater of the signals N and O.

Claim 49

delivering a signal M responsive to the computation of step (18); comparing signals J and M; delivering a signal N responsive to the difference between signals J and M; comparing signal N with a set point signal O; and controlling the flow rate of the air stream in response to the greater of the signals N and O.