This is a boiler feed water treatment process that aims to remove suspended solid impurities in a boiler to enhance heat transfer efficiency. It is also a control strategy, whereby it limits the amount of corrosion caused by these impurities. The rate of blowdown in this system helps in eliminating the levels of contamination in the boiler unit.
Continuous Blow Down (CBD) removes
Dissolved salts , where as Intermittent Blow Down (IBD) removes suspended salts.
The highest concentration of contaminates and suspended salts are at the surface that is a phenomenon of boiling anything (think of the scum that forms in a pot when boiling potatoes as example ). This must be removed to prevent carrying over into the superheater (if it is equipped with one) or the Steam header.
All dissolved and suspended solids in the feed water to the boiler tend to concentrate in the boiler water as steam is generated. The boiler water has concentration limits (eg. total solids, silica content, alkalinity, etc) to avoid foaming and solids carryover. Continuous blowdown is taken from the zone of highest solids concentration in the steam drum and is usually capable of keeping solids within the required concentration limits. Intermittent blowdown is taken from the bottom of the steam drum and is used to keep it sludge-free during operation.
The common ways of doing a blowdown in a boiler are:
The manual blowdown (IBD)
The continuous blowdown (CBD)
Control of the blowdown process is essential to preventing explosions and other problems caused by flash steam and pressure differences
Types of blowdown ways And why it's important
This is a boiler feed water treatment process that aims to remove suspended solid impurities in a boiler to enhance heat transfer efficiency. It is also a control strategy, whereby it limits the amount of corrosion caused by these impurities. The rate of blowdown in this system helps in eliminating the levels of contamination in the boiler unit.
Continuous Blow Down (CBD) removes
Dissolved salts , where as Intermittent Blow Down (IBD) removes suspended salts.
The highest concentration of contaminates and suspended salts are at the surface that is a phenomenon of boiling anything (think of the scum that forms in a pot when boiling potatoes as example ). This must be removed to prevent carrying over into the superheater (if it is equipped with one) or the Steam header.
All dissolved and suspended solids in the feed water to the boiler tend to concentrate in the boiler water as steam is generated. The boiler water has concentration limits (eg. total solids, silica content, alkalinity, etc) to avoid foaming and solids carryover. Continuous blowdown is taken from the zone of highest solids concentration in the steam drum and is usually capable of keeping solids within the required concentration limits. Intermittent blowdown is taken from the bottom of the steam drum and is used to keep it sludge-free during operation.
The common ways of doing a blowdown in a boiler are:
The manual blowdown (IBD)
The continuous blowdown (CBD)
Control of the blowdown process is essential to preventing explosions and other problems caused by flash steam and pressure differences
Hello, chemical engineering here. . 
No comments:
Post a Comment