Blowdown is a process where water is intentionally blown out of a boiler to remove impurities like carbon deposits, dirt, and foam. It is done through either intermittent or continuous blowdown. Feedwater treatment is also important and involves processes like filtration, softening, and demineralization to control deposits, prevent corrosion and scaling, and maintain steam purity by removing impurities from water used in boilers. Both blowdown and feedwater treatment are important for improving boiler efficiency and lifespan.

1. 3/31/2022
BLOWDOWN AND FEEDWATER
TREATMENT 1
Presented by,
Navyashree V N

2.  Blowdown is a process in which intentionally
water is blown out of boiler.
 Blowdown is done to remove carbon deposits
and impurities from the boiler.
Why ?
 To remove solid particles, dirt, foam/oil from
the boiler water.
 To remove excess water in case of emergency.
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BLOWDOWN AND FEEDWATER
TREATMENT 2

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BLOWDOWN AND FEEDWATER
TREATMENT 3
It is done in 2 ways,
1. Intermittent or Manual Blowdown
2. Continuous Blowdown

4.  Blowdown of boiler water at regular intervals
keeps the TDS impurities under the rated limits.
 The process helps in preventing corrosion as it
removes the impurities which accelerate the
corrosion process.
 It helps in preventing scaling of boiler tubes and
internal surface.
 It prevents the carryover of impurities and
contaminants with the steam, hence provides the
pure steam.
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BLOWDOWN AND FEEDWATER
TREATMENT 4

5.  If the procedure is not done correctly with the
determined schedule, the blowdown of boiler
water tends to increase the heat as well as pressure
losses.
 The heat and pressure losses from the boiler water
blowdown will reduce boiler efficiency.
 If the blowdown arrangement is manual,
additional work hours needed to conduct the
operation.
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BLOWDOWN AND FEEDWATER
TREATMENT 5

6.  Feed water treatment is a pre-water treatment
process to control deposition and to eradicate
impurities.
Why ?
 To prevent corrosion in boiler.
 To prevent the formation of scales.
 To maintain a high level of steam purity.
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TREATMENT 6

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TREATMENT 7

8.  Suspended solids and turbidity.
 Hardness( salts calcium of magnesium).
 Alkalinity(neutralize the water).
 Other dissolved ions(sodium, sulphate,
chloride).
 Silica.
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TREATMENT 8

9. 1. Filtration and ultrafiltration.
2. Softening.
3. Membrane processes.
4. Degasification.
5. Demineralization.
6. De-alkalization.
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TREATMENT 9

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TREATMENT 10
Fig(a)- Demineralizing Plant
Fig(b)-Membrane Treatment

11. THANK
YOU
3/31/2022
BLOWDOWN AND FEEDWATER
TREATMENT 11