1. 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

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

3. 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)

4. 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

5. 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

6. 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

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

8. 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

9. 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

10. 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

11. 1D3D dpc = 3.9 2D2D dpc = 4.0
1D2D dpc = 7.5

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

14. 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

15. 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

16. Twelve 1D2D Cyclones

17. 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