5 replies to this topic

[vne]

I see the phrase "steam blowdown" in some reading. After asking some friends, I received different answers. Some one said that it's the steam to clean up pipeline, equipment; while other said it is for removing contaminants from the steam.

Anyone can help clarify this one?

Thank you.

[shan]

'vne', on 20 Oct 2009 - 05:02 AM, said:

I see the phrase "steam blowdown" in some reading. After asking some friends, I received different answers. Some one said that it's the steam to clean up pipeline, equipment; while other said it is for removing contaminants from the steam.

Anyone can help clarify this one?

Thank you.

There are two kinds of “steam blowdown”.

1. When the plant is started up, steam is flowed through some operation units for cleaning up pipeline and equipment.
2. During boiler operation, water (condensate) is extracted from bottom of boiler to get ride of impurities accumulated in the boiler feed water.

Therefore, both your friend are right. The question is what your situation

[djack77494]

To expand a bit on shan's response about boiler blowdown, there are two kinds of boiler blowdown. There is the continuous blowdown, frequently drawn through a special adjustable valve and often from the the middle of the bottom drum (the Mud Drum), and intermittent blowdown drawn from quite low in the Mud Drum. The intermittent blowdown is to remove solids and non-soluble impurities that enter the boiler. The continuous blowdown is to control the concentration of soluble impurities.

[ankur2061]

'vne', on 20 Oct 2009 - 05:02 AM, said:

I see the phrase "steam blowdown" in some reading. After asking some friends, I received different answers. Some one said that it's the steam to clean up pipeline, equipment; while other said it is for removing contaminants from the steam.

Anyone can help clarify this one?

Thank you.

vne,

The strictest sense of the term 'Steam Blowdown' is reserved for blowdown from the steam drum of a steam boiler. For cleaning piping/equipment with steam the term 'Steam Out' or 'Steam Flushing' is more commonly employed.

'Steam Blowdown' from boiler drum may be intermittent or continuous depending on the type of boiler whereas 'Steam Out' or 'Steam Flushing' is generally only applicable during commisioning, start-up & shut-down of equipment/piping and hence is totally intermittent in nature.

Hope this helps.

Regards,
Ankur.

[vne]

Thanks for you all, guys. Your answers brighten me up.

[Harris]

'vne', on 21 Oct 2009 - 02:57 AM, said:

Thanks for you all, guys. Your answers brighten me up.

Steam blowdown come from the downcomers of the boiler (drum boiler), when the steam condenses it blows down and returns to the bled steam then to the superheaters of the boiler. On the 'once through boilers' the steam blowdown occurs when the steam from the turbine comes back as cold reheat to the boiler reheaters.

We then have the steam blowthrough, that is when we clean the boiler after commissioning the boiler (also called steam flushing) to remove the contaminants of the boiler.