1D2D Low Pressure Cyclone: Large Dust, High Lint Collector Shay L. Simpson Calvin B. Parnell, Jr., PhD, PE Texas A&M University 2008 Beltwide Cotton Conferences – Nashville

1D2D LPC Low Pressure < 2 in wg Summary of my Thesis work 1993 to 95 Updated applying research findings from Wang Faulkner

Why a 1D2D LPC? Fine Mesh Screens on lint cleaner condenser drums & battery condenser Axial-flow fans Generate large air volumes Back pressure less than 2 in wg Over 35% gin emissions from 1st stage lint cleaning (AP-42, U.S. EPA,1985)

Can’t I Use 1D3D or 2D2D? Yes, BUT first Change fans to in-line centrifugal fans 1D3D/2D2D pressure drops 4-5 in wg $$$ per gin Operate 1D3D & 2D2D at higher velocities –> increased energy 33% more energy Cycling lint problem – choke ups DOWNTIME

1D2D Low Pressure Cyclone 1D2D LPC 1D2D Low Pressure Cyclone Bc = Dc/4 Hc = Dc/2 Sc = Dc/8 De = Dc/1.6 Jc = Dc/2 Lc = Dc Zc = 2Dc

1D3D & 2D2D 1D3D Cyclone Bc = Dc/4 Hc = Dc/2 Sc = Dc/8 De = Dc/2 Jc = Dc/4 Lc = Dc Zc = 3Dc 2D2D Cyclone Bc = Dc/4 Hc = Dc/2 Sc = Dc/8 De = Dc/2 Jc = Dc/4 Lc = 2Dc Zc = 2Dc

Dimension Comparison Cyclone Dust Outlet Air Exit 1D2D D/2 D/1.6 1D3D

Performance Characteristics Cyclone Design Inlet Velocity Pressure Drop 1D2D 2400 ± 400 fpm 1.57 in wg 1D3D 3200 ± 400 fpm 4.30 in wg 2D2D 3000 ± 400 fpm 3.43 in wg Std Air

Performance Characteristics (cont.) Cyclone No. Turns Cut Point Slope 1D2D 2.6 7.5 μm 1.30 1D3D 6.0 3.9 μm 1.20 2D2D 4.0 μm

Cut Point Where Based on Lapple’s equation and Wang’s research dpc= diameter particle collected with 50% efficiency, m μ = Viscosity, kg/m∙s W = Width of cyclone inlet, m Ne = Number turns Vi = Design inlet velocity, m/s ρp = Particle density, kg/m3 Based on Lapple’s equation and Wang’s research

1D3D dpc = 3.9 2D2D dpc = 4.0 1D2D dpc = 7.5

Fly ash ~ MMD 13 GSD 1.7 Cotton gin dust ~ MMD 20 GSD 2.0

Dust Type Loading Wang et al. (2002) Fine Dust Only 1.5 mg/m3 1D3D 50 mg/m3 2D2D 67 mg/m3 1D3D 75 mg/m3 Trash/Fine Dust 1D3D & 2D2D – some choking 1D2D no choking Trash/Fine Dust w Lint (>1%) 1D2D Superior

1D2D Used In Texas Before installation Installed 12 cyclones Lint fly covering trees, ground, power lines Neighbor complaints Installed 12 cyclones Lint cleaner exhaust Bat. Condenser exhaust Trash exhaust After installation “Clean grounds” No complaints about lint fly

Twelve 1D2D Cyclones

Uses of 1D2D In pressure sensitive applications Reduce emissions from circulating fibers Lint Hulls Large trash collector Prevent choke ups Pre-collector in series with 1D3D or 2D2D cyclones