Fluidized Bed type CMC utilizing Coke Oven Exhaust Gas · PDF fileOutline and Process flow and...

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Fluidized Bed type CMC

utilizing Coke Oven

Exhaust Gas

CMC (Coal Moisture Control)

Nippon Steel & Sumikin Engineering Co.,Ltd.


Content

1.Introduce of CMC Outline and Process flow and Merits

2.CMC’s Drying Method Comparison of Drying Method

3.Fluidized Bed type CMC Nippon Steel & Sumikin Engineering’s FB type CMC and Chinese One

4.Experiment for Comparing two FB type CMC Drying Efficiency and Fluidized Bed Condition

5. Conclusion


Outline of CMC

CMC (Coal Moisture Control)

Coal Blending

Bin

Coke

Oven

Drying Wet Coal and Reducing Coal Moisture

Wet Coal Approx. 10% Moisture

Dry Coal Approx. 6-7% Moisture


CMC Process Flow

Coke Oven

Heat

Wet Coal Approx.10%

Bag Filter

Dryer Coal Blending Machine

Dry Coal Approx. 6-7%


・Prevention of Global Warming ・Expanding Demand for Iron ( in Asia ) ・Expanding Demand for Coal( in Asia )

Global circumstances and Role of CMC

・Energy Saving

Needs

・ Increase the Amount of Low-Quality Coal Usage

・ Coke Production Increase

CMC can meet those needs.


Reference: Merit of Coke Oven Waste Heat-recovery type CMC (Actual case of coke ovens in Japan when the moisture content is reduced by 4%)

Energy Saving of Coke Oven （Approx. 340MJ/t-coal）

Coke Production Increase (Approx.11%)

Fifth International Iron and Steel Congress (1986) p312

Coke Quality Improvement (DI150: Approx.1.7%) 15

Merits of CMC


Coal

Steam

Air

＜Cross section＞

Steam

Wet coal Air (Exhaust)

Dried coal

Air

Steam

Coal

＜Cross section＞

STD (Steam Tube Dryer) CIT (Coal in Tube)

Comparison of Drying Method

Wet coal Air (Exhaust)

Dried coal

Air Steam

Wet coal

Coke oven exhaust gas

Dried coal

Coke Oven Exhaust Gas

Exhaust gas +

Fine Coal

Fluidized Bed

FB (Fluidized Bed)

Coal

Nippon Steel & Sumikin Engineering


Comparison of Drying Method

Type STD CIT FB

Drying method

・Multi-Tube ・Steam Inside ・Indirect Heat Transfer

・Multi-Tube ・Coal Inside ・Indirect Heat Transfer

・Fluidized Bed ・Direct Heat Transfer

Heat resource ・Steam ・Steam ・Coke Oven Exhaust Gas

Energy Cost ・Need External Heat Source

・Need External Heat Source

・Utilizing Waste Heat

Maintenance Cost

・A lot of Machine Parts (Rotary Drum … Fatigue , Wear )

・A lot of Machine Parts (Rotary Drum … Fatigue , Wear )

・Box type Structure ( Few Machine )

lowest cost

lowest cost


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Exhaust Gas

Approx.10%

Heat resource

for drying coal

is unnecessary

Gas

Coal

Coke

Oven

Stack(existing)

Gas Duct

Recycle Gas

No.1 Blower

No.2 Blower

Stack(new)

Bug Filter

Wet Coal

Dry coal

Hopper

Fluidized

Bed

Dryer

Dry Coal

Coal

Blending

Machine

Approx.6-7%

Approx.200℃

Approx.60℃

coal

coal

Nippon Steel & Sumikin Engineering’s FB type CMC Process Flow


2 Kinds of FB type CMC

Differences (Depending on Grain size) → ・drying efficiency ・fluidized condition

・Nippon Steel & Sumikin Engineereing’s FB … Drying coking coal after pulverization.

Fluidized Bed Dryer

Coal Coal Coal

Pulverizer

・Chinese FB … Drying coking coal before pulverization.

Coal Coal

Fluidized Bed Dryer

Coal Pulverizer


40

50

60

70

80

90

0 1 2 3 4 5 6 7

Dryin

g e

ffic

ien

cy

(%

)

Average grain size (mm)

Drying Efficiency Drying Efficiency = (①Evaporative Latent Heat) / (②Heat Value Required for Drying)

Nippon Steel & Sumikin Engineering’s FB is Suitable for CMC !

Small Grain Size High Drying Efficiency


Fluidized Bed Condition

Large Particle

High Temp.

Low Temp.

Different Type

Coal

Small Particle

Uniform Temp.

NSEC

Coal

0

10

20

30

40

50

60

70

80

90

100

110

120

0 5 10 15 20 25 30 35 40 45 50 55 60

Flu

idiz

ed

bed

tem

peratu

re (℃

)

Time (sec)

1.3mm

5.34mm

8.88mm

13.24mm

Small Grain Size Few Partial Overheat or Excess Drying

Nippon Steel & Sumikin Engineering’s FB is Suitable for CMC !


・CMC have three merits. 1.Energy Saving of Coke Oven（Approx. 340MJ/t-coal） 2.Coke Quality Improvement(DI150: Approx.1.7%) 3.Coke Production Increase(Approx.11%)

・ Energy and maintenance cost is the lowest by drying Nippon Steel & Sumikin Engineering’s FB type CMC to compare to STD and CIT. ・ Drying coal by FB dryer case, So, drying after pulverization is suitable for FB dryer.

Conclusion

15

Small Grain Size Few Partial Overheat or Excess Drying

High Drying Efficiency

Fluidized Bed type CMC utilizing Coke Oven Exhaust Gas · PDF fileOutline and Process flow and...

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