xxxx 26/02/2010 09:38:50

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

Vikpro 01/03/2010 15:03:50

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

Mill Length

Mill Capacity

t/h

Gypsum %

Clinker input

17.28

t/h

Gypsum input

0.72

t/h

Power input, Mill

600

Clinker Temp. ( Tk )

Gypsum Temp. ( Tg)

Cement Temp. ( Tc)

Temp. of Air ( TL )

Mill vent Air per kg of Cement.

0.567

m3 / kg Cement

Mill Ventilation temp Avg.

Mill surface Temp

Mill Surface Area

90.5

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.

KWh

3) Losses by heating the mill vent Air.

KWh

4) Losses not measurable such as sound generation &

KWh

Vibration.

5) Total KWh

6)Total % of power converted into Heat.

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

Vikpro 01/03/2010 15:05:49

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

Mill Length

Mill Capacity

t/h

Gypsum %

Clinker input

17.28

t/h

Gypsum input

0.72

t/h

Power input, Mill

600

Clinker Temp. ( Tk )

Gypsum Temp. ( Tg)

Cement Temp. ( Tc)

Temp. of Air ( TL )

Mill vent Air per kg of Cement.

0.567

m3 / kg Cement

Mill Ventilation temp Avg.

Mill surface Temp

Mill Surface Area

90.5

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.

KWh

3) Losses by heating the mill vent Air.

KWh

4) Losses not measurable such as sound generation &

KWh

Vibration.

5) Total KWh

6)Total % of power converted into Heat.

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

Vikpro 01/03/2010 15:07:16

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

Mill Length

Mill Capacity

t/h

Gypsum %

Clinker input

17.28

t/h

Gypsum input

0.72

t/h

Power input, Mill

600

Clinker Temp. ( Tk )

Gypsum Temp. ( Tg)

Cement Temp. ( Tc)

Temp. of Air ( TL )

Mill vent Air per kg of Cement.

0.567

m3 / kg Cement

Mill Ventilation temp Avg.

Mill surface Temp

Mill Surface Area

90.5

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.

KWh

3) Losses by heating the mill vent Air.

KWh

4) Losses not measurable such as sound generation &

KWh

Vibration.

5) Total KWh

6)Total % of power converted into Heat.

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