Explosion Vented Equipment System Protection Guide. Robert C. Comer

reactions on panels and reinforcing members, lbs/in.Rocylinder radius, in.Saallowable stress (2/3 of the 0.2% yield strength), psiScSection modulus of reinforcing composite member, in.3Sstresses in material, psiSuultimate strength of the material, psitpthickness of the panel, in.twweld size, in.Tbolt torque, in.‐lbsTttotal load on panel, lbsTpthickness of reinforcing ring, in.vPoisson's ratioVoshear load on panel edge, lbsVmmaximum vertical shear end reaction load, total load/2, lbsVhhorizontal shear between panel and reinforcing member, = Vm Q/Ic = lbs/in.wuniform edge load acting on the reinforcing member, lbs/in. = Rmax × 2 panelsw.g.water gauge pressure, inches of water, psiWbmaximum individual bolt load, lbsWpwidth of panel or reinforcing ring, in.wt/ftweight per foot of reinforcing member, lbs/ftymaxmaximum deflection of the panel, in.Zdistance of bolt farthest from neutral axis, in.

      Greek Symbols

      αcoefficient from Table 2.1βcoefficient from Table 2.1∆growth of cylinder under load, in.σ x,y stress in cylinder wall, psiσmaxstress in head, psi

      Note: All pressures are gage pressures unless otherwise indicated.

      Typical Dust Collection System Checklist

      Example (Rectangular Dust Collector)

      System Identification: Typical dust collector example

      Process Product: No specific product assumed

      Product P_{max_____________} Product K_st________ P_red = 5.0 psi assumed

      Basis of P_max and K_st: Was product dust tested ____Y ____X __N

      Were values approximated from a chart ____Y ___X ___N

      Other: Average values assumed for this example

      Dust collector: If square or rectangular

       Pressure rating from manufacturer: ±20 in water gauge

       Basis for rating: 60% of 0.2% yield strength, or other__________

       Is vessel located inside or outside? Inside

       Top width: 97.75 in. Depth: 38.25 in. Height: 27.75 in.

       Top sheet thickness: 10 ga. (0.1345 in.)

       Sides height: 108.25 in.

       Sidewall thickness: 10 ga. (0.1345 in.)

       Reinforcing on top or walls: None

       Volume of dust collector: N/A

      Dust collector: If cylindrical

       Pressure rating from manufacturer:_________________

       Basis for rating: ________% of 0.2% yield strength, or other_______

       Diameter: _________

       Type of top: Flat______ Ellipsoidal__________ Torispherical_______

       Thickness of top: _______

       Thickness of cylinder wall: _______

       Length of cylinder: ______________

       Volume of dust collector: ______________________________________

       Hopper height: 30.50 in. Discharge size: 9.25 in. × 9.25 in.

       Hopper wall thickness: 10 ga. (0.1345 in.)

       Dust collector/hopper flange size and thickness: 2″ × 2″ × 1/4″ angle

       Bolt size and spacing: _________________________________________

       Volume of hopper: N/A

       Number of bags/cartridges: N/A

       Bag/cartridge diameter: __________ Number of bags/cartridges: ______

       Bag/cartridge volume: ______________

       Access door width and height: 37.875 in. × 40 in.

       Access door thickness: 10 ga. (0.1345 in.)

       Reinforcing on door: None

       Type of latching:Clamps________________ Bolts _________________________Hinges ____________ Hinge pin diameter __________________

       Nozzles: Diameter __________________________________

       Dusty air inlet dimensions: _____________________________

       Clean air outlet dimensions: ____________________________

       Leg supports:Size: ______ Number of supports: 4 Length of supports: 78.50 in.Footpad size and thickness: 7.50 in. × 7.50 in. × 1/2 in.Attachment to floor or ground: 3/4 in bolts to floor

      Explosion vent information:

       Manufacturer/part number: N/A

       Size: Round _______ Square/rectangular: 24 in. × 24 in.

       Vent pressure rating: 1.0 psi ± 0.25 psi Vent area: ___________________

       Flange size: 2″ × 2″ × 1/4″ angle Bolt size and number

       Distance from top of dust collector: 35 in.

      Duct information:

       Size: 24 in. × 24 in. Length: Wall thickness: 10 ga. (0.1345 in)

       Any bends at end of duct?

      Screw conveyor:

       Cover width __________ Cover length _________ Thickness _________

       Spacing and size of bolts or clamps on cover:

      Acknowledgments

      It is a pleasure to acknowledge my appreciation to people that inspired this manuscript. I am particularly indebted to George Petino, Jr., MME, P.E., Dust Explosion Consultant and owner of Hazards Research Corporation, who provided me with the opportunity to consult with facilities worldwide in mitigating their dust explosion hazards. His professional mentoring and guidance has been extraordinary.

      I am also indebted to my son‐in‐law Jack Kehlenbeck who aided in compiling the manuscript, his computer skills are outstanding.

      NFPA, National Fire Protection Association, must be applauded for their work in making and keeping the Standards on Explosion Protection by Deflagration Venting viable and progressive.

      I must thank John Wiley & Sons, Inc., Project Editors Ms Beryl Mesiadhas, Michael Leventhal, Summers Scholl, and Vishnu Priya for their excellent professional guidance.

      Finally, as always, I could accomplish nothing without the support and encouragement of my wife Jean.