gas solid flow in a cfb with l-valve and impact of gas distribution changes … · 2017-02-21 ·...
TRANSCRIPT
Gas solid flow in a CFB with L-valve and impact of gas distributionchanges in the design
Arenales, J., Perez, V. and Murillo, J.M.
26 September 2014 169th IEA-FBC meeting
Jorge Arenales Rivera
CEDER-CIEMAT
Autovia A-15, Salida 56, 42290, Lubia (SORIA)
e-mail: [email protected]
Tlf:975-281013
Circulating fluidized bed gasifier
• Main design parameters
– Size
• Driser: 300 mm; Hriser: 8800 mm
– Maximum operation pressure: 0.2 bar
– Maximum temperature: 950 ºC
– Gas velocity: 3-6 m/s
– Maximum air gasification flow rate: 300 Nm3/h
– Fuel rate: 100 kg/h
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Circulating fluidized bed gasifier
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Circulating fluidized bed gasifier
• Gas/solids flow performance
– Selection of bed material
– Exit type
• Abrupt exit
– Solids flow control (aireation)
• U-type loop-seal
– Recycle chamber
– Supply chamber
– Horizontal passage
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Bed material
• Bed material
– Silica sand
204 μm/428 μm
ρp ~2500 kg/m3
ρbulk ~1520 kg/m3
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Geldart, D. Powder Technology, 1, 285, 1973
Bed material
• Granulometry – Conventional method
• Sand 204 μm
• Sand 428 μm
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pii
pdx
d/
1
0,00
10,00
20,00
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0 1 2 3 4
Volu
me (%
)
Particle diameter (mm)
204
428
CFB Cold flow model
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CFB Cold flow model
• Main design parameters
– Plexiglas model
• Driser: 192 mm; Hriser: 4550 mm
• Dstandpipe: 92 mm; Hstandpipe: 2700 mm
• DL-valve: 92 mm; Lhorizontal passage: 480 mm
– Maximum operation pressure: 0.2 bar
– Gas velocity: 3-6 m/s
– Maximum air gasification flow rate: 600 Nm3/h
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Bed material selection
• Sand a) 428 μm– Solids inventory: 25-35 kg
– Aireation flow rate: 50-70 L/min
– Superficial velocity: 5-6 m/s
• Sand b) 204 μm– Solids inventory: 25-35 kg
– Aireation flow rate: 25-46 L/min
– Superficial velocity: 3.5-5 m/s
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Solids flow measurement
• External solids flow
– Butterfly valve
– Graduate Pipe
• Internal solids flow
– Non-isokinetic probe
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Solids flow measurement
• External solids flow
– Solids mass flux (Gs)
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Solids flow measurement
• Internal solids flow
– Solids mass flux
Preliminary results (non-isokinetic probe)
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Solids inventory
(35 kg)
Aireation flow rate
(37 L/min)
Internal solids
mass flux (kg/sm2)
External solids
mass flux (kg/sm2)
us (4 m/s) 27 6.4
us (4,5 m/s) 31.8 10.6
Circulating fluidized bed gasifier
• Gas distributor design
– Riser
• Bubble-cap type
(abrasion)
– Loop-seal
• Perforated pipes
(Supply chamber)
(Recycle chamber)
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Non-mechanical valve
• Supply chamber
– Aireation tap
(L-valve design)
• Recycle chamber
– Perforated pipes
– Perforated plate
– Porous plate
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Solids flow measurement
• Perforated plate
– Staggered
distribution
– Dhole: 1 mm
– Step: 0.129 mm
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Solids flow measurement
• Porous plate
– Glass filter
– Por. 2 P100
(ISO 4793-80)
– Poresize 40-100 μm
– Diameter: 140 mm
– Tickness: 10 mm
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Future work
• Test different bed materials
• Experiments with an U-type loop-seal in a
CFB cold flow model
• Re-design of loop-seal in the circulating
fluidized bed gasifier pilot plant
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Thank you for your attention
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