Abstract
A needle penetrometry was performed loading steady force in a range from 1 × 10-3 to 2 N to pelletized coal upon heating via a cylindrical needle. From the observed effects of shear rate on apparent viscosity of softening coal pellet, defined as the shear-rate to shear-stress ratio, it was found that the pellet behaved as a Newtonian fluid for shear rates lower than a critical one while as a pseudo-plastic fluid for higher shear rates. The penetrometry was also carried out varying the force with time. The variable force loading enabled to maintain the shear rate well below the critical one, and thereby to measure the apparent viscosity of coal pellets as Newtonian fluids over a temperature range from 600 to 800 K. Upon heating at 10 K min-1, the apparent viscosity of Goonyella coal pellet decreased from about 1010 Pa s at 640 K down to a minimum of about 104 Pa s at 755 K, and increased up to 109 Pa s at 800 K. In a course of heating as above, the viscosity of Blind Canyon coal pellet decreased above 600 K, underwent a minimum of about 106 Pa s at 715 K, and increased up to 1010 Pa s at 770 K. Decreasing the heating rate from 10 to 3 K min-1 caused the minimum viscosities of the pellets to increase by 1-2 orders of magnitude.
| Original language | English |
|---|---|
| Pages (from-to) | 487-500 |
| Number of pages | 14 |
| Journal | Fuel |
| Volume | 82 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - Mar 1 2003 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Fuel Technology
- Energy Engineering and Power Technology
- Organic Chemistry
Cite this
Needle penetrometry with variable force loading for measuring viscosity of pelletized coal upon heating. / Jun-Ichiro, Hayashi; Morita, Masato; Kumagai, Haruo; Chiba, Tadatoshi.
In: Fuel, Vol. 82, No. 5, 01.03.2003, p. 487-500.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Needle penetrometry with variable force loading for measuring viscosity of pelletized coal upon heating
AU - Jun-Ichiro, Hayashi
AU - Morita, Masato
AU - Kumagai, Haruo
AU - Chiba, Tadatoshi
PY - 2003/3/1
Y1 - 2003/3/1
N2 - A needle penetrometry was performed loading steady force in a range from 1 × 10-3 to 2 N to pelletized coal upon heating via a cylindrical needle. From the observed effects of shear rate on apparent viscosity of softening coal pellet, defined as the shear-rate to shear-stress ratio, it was found that the pellet behaved as a Newtonian fluid for shear rates lower than a critical one while as a pseudo-plastic fluid for higher shear rates. The penetrometry was also carried out varying the force with time. The variable force loading enabled to maintain the shear rate well below the critical one, and thereby to measure the apparent viscosity of coal pellets as Newtonian fluids over a temperature range from 600 to 800 K. Upon heating at 10 K min-1, the apparent viscosity of Goonyella coal pellet decreased from about 1010 Pa s at 640 K down to a minimum of about 104 Pa s at 755 K, and increased up to 109 Pa s at 800 K. In a course of heating as above, the viscosity of Blind Canyon coal pellet decreased above 600 K, underwent a minimum of about 106 Pa s at 715 K, and increased up to 1010 Pa s at 770 K. Decreasing the heating rate from 10 to 3 K min-1 caused the minimum viscosities of the pellets to increase by 1-2 orders of magnitude.
AB - A needle penetrometry was performed loading steady force in a range from 1 × 10-3 to 2 N to pelletized coal upon heating via a cylindrical needle. From the observed effects of shear rate on apparent viscosity of softening coal pellet, defined as the shear-rate to shear-stress ratio, it was found that the pellet behaved as a Newtonian fluid for shear rates lower than a critical one while as a pseudo-plastic fluid for higher shear rates. The penetrometry was also carried out varying the force with time. The variable force loading enabled to maintain the shear rate well below the critical one, and thereby to measure the apparent viscosity of coal pellets as Newtonian fluids over a temperature range from 600 to 800 K. Upon heating at 10 K min-1, the apparent viscosity of Goonyella coal pellet decreased from about 1010 Pa s at 640 K down to a minimum of about 104 Pa s at 755 K, and increased up to 109 Pa s at 800 K. In a course of heating as above, the viscosity of Blind Canyon coal pellet decreased above 600 K, underwent a minimum of about 106 Pa s at 715 K, and increased up to 1010 Pa s at 770 K. Decreasing the heating rate from 10 to 3 K min-1 caused the minimum viscosities of the pellets to increase by 1-2 orders of magnitude.
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U2 - 10.1016/S0016-2361(02)00332-0
DO - 10.1016/S0016-2361(02)00332-0
M3 - Article
VL - 82
SP - 487
EP - 500
JO - Fuel
JF - Fuel
SN - 0016-2361
IS - 5
ER -