This mostly self explanatory presentation discusses what properties of coal blend well, and the impacts it may have on combustion. Wall slag is discussed along with the Rod Hatt Splat Factor, where I try to show how low CV coal can increase slag by itself. For more coal information please see our social media page: http://www.coalcombustion.com/social%20media.html
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20. Many slagging concerns
have been addressed using
Ash Loading and Elemental
loading levels; especially
Fe2O3, CaO, Na2O
21. Lessons Learned From Experience
1. Ash Fusion Temps do not
work
2. Increase in Moisture Causes
more Slag
3. Lowering Sodium by Dilution
Causes more Slag
22. B/A Ratio
Fusion
Fusion verse Base to Acid Ratio
Low Sulfur Bit
Mid/High Sulfur
Fe2O3
High Calcium
Sub Bit
0 0.5 1.0 1.5
39. Splat Factor
Velocity is Important
Kinetic Energy =
Mass x (velocity)2
2
Large dense particles
Pyrite Quartz, rock
Coal pipe velocity
Low Btu, Hi Moist.
Hi PA Flow
40. SPLAT FACTOR
Coal Pipe Velocity increases
due to:
1. High PA flow (mill A/F)
2. Low CV coal
3. High moisture
41. SPLAT FACTOR
1. Calculate KE for Quartz and
Pyrite particles
2. Multiply KE times Q & P
loading levels
3. Multiply result by % on 50
mesh screen
(>300 microns)
42. SPLAT FACTOR
Low with low levels of large
particles
Low with low levels of ash and
sulfur
Lowers with less PA flow A/F
is important
43. Coal Combustion
43
Bituminous
1.Maintain 70%+ passing 200 mesh screen
2.High Calorific Value and low moisture
allow for low mill loading
3.Lower Primary Air due to lower coal flow
can allow for rejects
44. Coal Combustion
44
Sub - Bituminous
1.Maintain 70% passing 200 mesh screen to
Minimize Slag, (lower to increase ton rate)
2.Low Calorific Value and high moisture
make for high mill loading
3.High Primary Air for drying and high coal
flow sends reject material into the furnace
45. Advice – Set up plant
1.Pulverize to meet Un-reactive coal
2.Pulverize for slag control-not carbon
3.Maintain CV to take load off mill
or
1.Change Expectation – Load, Forced
Outage Rate (SLAG, TUBE LEAK)
Maintenance