237 posts
TimePosted 26/02/2010 09:38:50
xxxx says

### aux. furnace coal consumption

my coal ball mill is 2.5 *4m with 10 tph having coal with 7 % input moisture & 1 % output moisture.

it is connected with a auxiliary furnace.

i want to calculate the amount of coal fired into the furnace to get grind the coal.

Mill outlet temp . 80 deg

velocity through mill 1.5 m/s

gr. media in mill is 27 t

rajesh

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77 posts
TimePosted 01/03/2010 15:03:50
Vikpro says

### Re: aux. furnace coal consumption

Dear Mr. Rajesh,

sending you two excel sheet ( pasted ) . Please send me your mill's details as shown below ( in Bold ) to get full report.

Vikpro

Grinding and Generation of Heat.

Mill Dia         2.2 m
Mill Length       12 m
Mill Capacity       18 t/h
Gypsum %       4 %
Gypsum input       0.72 t/h
Power input, Mill       600 kW
Clinker Temp. ( Tk )       15 C
Gypsum Temp. ( Tg)       15 C
Cement Temp. ( Tc)       95 C
Temp. of Air      ( TL )     15 C
Mill vent Air per kg of Cement.     0.567 m3 / kg Cement
Mill Ventilation temp Avg.     45 C
Mill surface Temp       40 C
Mill Surface Area       90.5 M2
Specific Heat of Cement     0.184 Kcal / Kg
Radiation of Mill shell / m2     200 Kcal
Specific Heat of Air.       0.312 Kcal
1) Loss of efficiency by generating heat in the Mill  308 kWh

2) Loss by Radiation through mill shell.   21 KWh

3) Losses by heating the mill vent Air.   93 KWh

4) Losses not measurable such as sound generation & 3 KWh
Vibration.

5) Total KWh

6)Total % of power converted into Heat.   94 %

75 % of motor efficiency Considered.

 Heat Balance ( Mill ) Mill Dia 2.2 m Mill Length 12 m Mill Capacity 18 t/h Gypsum % 4 % Clinker input 17.28 t/h Gypsum input 0.72 t/h Power input, Mill 2436 Kw Power input, Motor 600 Kw Clinker Temp. ( Tk ) 15 C Gypsum Temp. ( Tg) 15 C Cement Temp. ( Tc) 95 C Temp. of Air      ( TL ) 15 C Temp. of Water      ( Tw ) 15 C Mill Ventilation temp Avg. 45 C Normal H2O vapour in Dry Air 0.2 0.28 kg H2O vapour / kg dry air. Mill surface Temp 40 C Mill Surface Area 90.5 M2 Total Heat Input Heat entering Mill with Clinker 49248 K cal / hr Heat entering Mill with Gypsum 2797.2 K cal / hr Heat entering Mill with Air. 4.665 K cal /kg air Heat entering Mill with Motor. 2094960 K cal / hr Total Heat entering Mill 2147005 K cal / hr Total Heat Output Heat leaving With H2O Vapour 621.7 K cal / kg H2O vapour / Kg Air Heat leaving with Air. 304367.9 K cal / kg 29.545 K cal / kg air Heat leaving with Cement 324900 Kcal / Hr Heat leaving through mill Surface 9854.108 Kcal / Hr Total Heat leaving Mill only 379196.9 K cal / hr Total amount of Air in Mill 10301.84 Kg / hr Air per ton of Cement 572.32 Kg / ton Total amount of Water in Mill 2431.23 Lit/ hr Amount of Water. lit/ ton cement 135.07 lit/ ton water Vapour / Kg Air 0.24 kg/kg Air With determined air Volume, and without water injection, the Cement Temp. would be …… 482.72 C

77 posts
TimePosted 01/03/2010 15:05:49
Vikpro says

### Re: aux. furnace coal consumption

Dear Mr. Rajesh,

sending you two excel sheet ( pasted ) . Please send me your mill's details as shown below ( in Bold ) to get full report.

Vikpro

Grinding and Generation of Heat.

Mill Dia         2.2 m
Mill Length       12 m
Mill Capacity       18 t/h
Gypsum %       4 %
Gypsum input       0.72 t/h
Power input, Mill       600 kW
Clinker Temp. ( Tk )       15 C
Gypsum Temp. ( Tg)       15 C
Cement Temp. ( Tc)       95 C
Temp. of Air      ( TL )     15 C
Mill vent Air per kg of Cement.     0.567 m3 / kg Cement
Mill Ventilation temp Avg.     45 C
Mill surface Temp       40 C
Mill Surface Area       90.5 M2
Specific Heat of Cement     0.184 Kcal / Kg
Radiation of Mill shell / m2     200 Kcal
Specific Heat of Air.       0.312 Kcal
1) Loss of efficiency by generating heat in the Mill  308 kWh

2) Loss by Radiation through mill shell.   21 KWh

3) Losses by heating the mill vent Air.   93 KWh

4) Losses not measurable such as sound generation & 3 KWh
Vibration.

5) Total KWh

6)Total % of power converted into Heat.   94 %

75 % of motor efficiency Considered.

 Heat Balance ( Mill ) Mill Dia 2.2 m Mill Length 12 m Mill Capacity 18 t/h Gypsum % 4 % Clinker input 17.28 t/h Gypsum input 0.72 t/h Power input, Mill 2436 Kw Power input, Motor 600 Kw Clinker Temp. ( Tk ) 15 C Gypsum Temp. ( Tg) 15 C Cement Temp. ( Tc) 95 C Temp. of Air      ( TL ) 15 C Temp. of Water      ( Tw ) 15 C Mill Ventilation temp Avg. 45 C Normal H2O vapour in Dry Air 0.2 0.28 kg H2O vapour / kg dry air. Mill surface Temp 40 C Mill Surface Area 90.5 M2 Total Heat Input Heat entering Mill with Clinker 49248 K cal / hr Heat entering Mill with Gypsum 2797.2 K cal / hr Heat entering Mill with Air. 4.665 K cal /kg air Heat entering Mill with Motor. 2094960 K cal / hr Total Heat entering Mill 2147005 K cal / hr Total Heat Output Heat leaving With H2O Vapour 621.7 K cal / kg H2O vapour / Kg Air Heat leaving with Air. 304367.9 K cal / kg 29.545 K cal / kg air Heat leaving with Cement 324900 Kcal / Hr Heat leaving through mill Surface 9854.108 Kcal / Hr Total Heat leaving Mill only 379196.9 K cal / hr Total amount of Air in Mill 10301.84 Kg / hr Air per ton of Cement 572.32 Kg / ton Total amount of Water in Mill 2431.23 Lit/ hr Amount of Water. lit/ ton cement 135.07 lit/ ton water Vapour / Kg Air 0.24 kg/kg Air With determined air Volume, and without water injection, the Cement Temp. would be …… 482.72 C

77 posts
TimePosted 01/03/2010 15:07:16
Vikpro says

### Re: aux. furnace coal consumption

Dear Mr. Rajesh,

sending you two excel sheet ( pasted ) . Please send me your mill's details as shown below ( in Bold ) to get full report.

Vikpro

Grinding and Generation of Heat.

Mill Dia         2.2 m
Mill Length       12 m
Mill Capacity       18 t/h
Gypsum %       4 %
Gypsum input       0.72 t/h
Power input, Mill       600 kW
Clinker Temp. ( Tk )       15 C
Gypsum Temp. ( Tg)       15 C
Cement Temp. ( Tc)       95 C
Temp. of Air      ( TL )     15 C
Mill vent Air per kg of Cement.     0.567 m3 / kg Cement
Mill Ventilation temp Avg.     45 C
Mill surface Temp       40 C
Mill Surface Area       90.5 M2
Specific Heat of Cement     0.184 Kcal / Kg
Radiation of Mill shell / m2     200 Kcal
Specific Heat of Air.       0.312 Kcal
1) Loss of efficiency by generating heat in the Mill  308 kWh

2) Loss by Radiation through mill shell.   21 KWh

3) Losses by heating the mill vent Air.   93 KWh

4) Losses not measurable such as sound generation & 3 KWh
Vibration.

5) Total KWh

6)Total % of power converted into Heat.   94 %

75 % of motor efficiency Considered.

 Heat Balance ( Mill ) Mill Dia 2.2 m Mill Length 12 m Mill Capacity 18 t/h Gypsum % 4 % Clinker input 17.28 t/h Gypsum input 0.72 t/h Power input, Mill 2436 Kw Power input, Motor 600 Kw Clinker Temp. ( Tk ) 15 C Gypsum Temp. ( Tg) 15 C Cement Temp. ( Tc) 95 C Temp. of Air      ( TL ) 15 C Temp. of Water      ( Tw ) 15 C Mill Ventilation temp Avg. 45 C Normal H2O vapour in Dry Air 0.2 0.28 kg H2O vapour / kg dry air. Mill surface Temp 40 C Mill Surface Area 90.5 M2 Total Heat Input Heat entering Mill with Clinker 49248 K cal / hr Heat entering Mill with Gypsum 2797.2 K cal / hr Heat entering Mill with Air. 4.665 K cal /kg air Heat entering Mill with Motor. 2094960 K cal / hr Total Heat entering Mill 2147005 K cal / hr Total Heat Output Heat leaving With H2O Vapour 621.7 K cal / kg H2O vapour / Kg Air Heat leaving with Air. 304367.9 K cal / kg 29.545 K cal / kg air Heat leaving with Cement 324900 Kcal / Hr Heat leaving through mill Surface 9854.108 Kcal / Hr Total Heat leaving Mill only 379196.9 K cal / hr Total amount of Air in Mill 10301.84 Kg / hr Air per ton of Cement 572.32 Kg / ton Total amount of Water in Mill 2431.23 Lit/ hr Amount of Water. lit/ ton cement 135.07 lit/ ton water Vapour / Kg Air 0.24 kg/kg Air With determined air Volume, and without water injection, the Cement Temp. would be …… 482.72 C