NR 664.1033(4)(d)1.1. Design a steam-assisted or nonassisted flare for and operate it with an exit velocity, determined by the methods specified in sub. (5) (c), less than 18.3 m/s (60 ft/s), except as provided in subds. 2. and 3. NR 664.1033(4)(d)2.2. A steam-assisted or nonassisted flare designed for and operated with an exit velocity, determined by the methods specified in sub. (5) (c), equal to or greater than 18.3 m/s (60 ft/s) but less than 122 m/s (400 ft/s) is allowed if the net heating value of the gas being combusted greater than 37.3 MJ/scm (1,000 Btu/scf). NR 664.1033(4)(d)3.3. A steam-assisted or nonassisted flare designed for and operated with an exit velocity, determined by the methods specified in sub. (5) (c), less than the velocity, Vmax, determined by the method specified in sub. (5) (d) and less than 122 m/s (400 ft/s) is allowed. NR 664.1033(4)(e)(e) Design and operate an air-assisted flare with an exit velocity less than the velocity, Vmax, determined by the method specified in sub. (5) (e). NR 664.1033(4)(f)(f) A flare used to comply with this section shall be steam-assisted, air-assisted or nonassisted. NR 664.1033(5)(a)(a) Use Method 22 in appendix A of 40 CFR part 60, incorporated by reference in s. NR 660.11, to determine the compliance of a flare with the visible emission provisions of this subchapter. Use an observation period of 2 hours according to Method 22. NR 664.1033(5)(b)(b) Calculate the net heating value of the gas being combusted in a flare using the following equation: where:
HT = Net heating value of the sample, MJ/scm; where the net enthalpy per mole of offgas is based on combustion at 25°C and 760 mm Hg, but the standard temperature for determining the volume corresponding to 1 mol is 20 °C
K = Constant, 1.74´10-7 (1/ppm) (g mol/scm) (MJ/kcal) where standard temperature for (g mol/scm) is 20°C
Ci = Concentration of sample component i in ppm on a wet basis, measured for organics by Method 18 in appendix A of 40 CFR part 60 and measured for hydrogen and carbon monoxide by ASTM D1946-82, both incorporated by reference in s. NR 660.11 Hi = Net heat of combustion of sample component i, kcal/9 mol at 25°C and 760 mm Hg. The heats of combustion may be determined using ASTM D2382-83, incorporated by reference in s. NR 660.11, if published values are not available or cannot be calculated NR 664.1033(5)(c)(c) Determine the actual exit velocity of a flare by dividing the volumetric flow rate (in units of standard temperature and pressure), determined by Methods 2, 2A, 2C or 2D in appendix A of 40 CFR part 60, incorporated by reference in s. NR 660.11, as appropriate, by the unobstructed (free) cross-sectional area of the flare tip. NR 664.1033(5)(d)(d) Determine the maximum allowed velocity in m/s, Vmax, for a flare complying with sub. (4) (d) 3. by the following equation: where:
28.8 = Constant
31.7 = Constant
HT = The net heating value determined in par. (b)
NR 664.1033(5)(e)(e) Determine the maximum allowed velocity in m/s, Vmax, for an air-assisted flare by the following equation: where:
8.706 = Constant
0.7084 = Constant
HT = The net heating value determined in par. (b)
NR 664.1033(6)(6) The owner or operator shall monitor and inspect each control device required to comply with this section to ensure proper operation and maintenance of the control device by implementing all of the following requirements: NR 664.1033(6)(a)(a) Install, calibrate, maintain and operate according to the manufacturer’s specifications a flow indicator that provides a record of vent stream flow from each affected process vent to the control device at least once every hour. Install the flow indicator sensor in the vent stream at the nearest feasible point to the control device inlet, but before the point at which the vent streams are combined.