Continuous stack flow rate monitor

Claim 1

Apparatus for calculating and displaying the flow rate of flue gases through a fan in a stack comprising: (a) first sensing means for sensing average air temperature within a stack on the discharge side of a motor driven fan including a plurality of thermocouples mounted within said stack; (b) second means for sensing average air temperature within a stack on an inlet side of said fan comprising a plurality of thermocouples mounted within said stack; (c) means for sensing the pressure at said inlet side of said fan; (d) means for determining the power output of said motor; (e) means operatively connected to said first and second temperature sensing means, said pressure sensing means, said power determining means to receive signals derived from the parameters measured thereby for converting said signals to a measurement of the rate of flow of flue gases through said fan based on the formula ##EQU2## where: T 1 =the inlet temperature in degrees Fahrenheit plus 460° F., T 2 =the outlet temperature in degrees Fahrenheit plus 460°, P 1 =the inlet static pressure in inches water gauge plus 406.9 inches, K=the ratio of gas specific heat at constant pressure to constant volume, T 2 -T 1 represents the measured temperature differential of the gas induced through the fan, F=the rated efficiency of the coupling or the coupling and the motor depending on whether P m is measured at the output or input of the motor, P m =the measured power, C o =a conversion constant for converting the measured power to a flow rate; and (f) means for displaying said stack flow.

Claim 8

A method for determining the flow rate of flue gases through a motor driven fan in conduit comprising the steps of: (a) measuring the temperature differential of the flue gases across said fan within said conduit; (b) measuring the inlet pressure of the gases incident to said fan; (c) determining the power input to said fan; (d) electronically calculating the flow rate through said fan using a programmable computer adapted to receive signals indicative of said measured temperature differential, said measured pressure, and said power and programmed to utilize the formula ##EQU3## where: T 1 =the inlet temperature in degrees Fahrenheit plus 460° F., T 2 =the outlet temperature in degrees Fahrenheit plus 460°, P 1 =the inlet static pressure in inches water gauge plus 406.9 inches, K=the ratio of gas specific heat at constant pressure to constant volume, T 2 -T 1 represents the measured temperature differential of the gas induced through the fan, F=the rated efficiency of the coupling or the coupling and the motor depending on whether P m is measured at the output or input of the motor, P m =the measured power, C o =a conversion constant for converting the measured power to a flow rate; and (d) displaying said flow rate on a visually perceptible display.

Claim 9

A method for determining the flow rate of flue gases through a motor driven fan in conduit comprising the steps of: (a) measuring the temperature differential of the flue gases across said fan within said conduit; (b) measuring the inlet pressure of the gases incident to said fan; (c) determining the power input to said fan; (d) electronically calculating the flow rate through said fan using a programmable computer adapted to receive signals indicative of said measured temperature differential, said measured pressure, and said power and programmed to utilize the formula ##EQU3## where: T 1 =the inlet temperature in degrees Fahrenheit plus 460° F., T 2 =the outlet temperature in degrees Fahrenheit plus 460°, P 1 =the inlet static pressure in inches water gauge plus 406.9 inches, K=the ratio of gas specific heat at constant pressure to constant volume, T 2 -T 1 represents the measured temperature differential of the gas induced through the fan, F=the rated efficiency of the coupling or the coupling and the motor depending on whether P m is measured at the output or input of the motor, P m =the measured power, C o =a conversion constant for converting the measured power to a flow rate; and (d) displaying said flow rate on a visually perceptible display.