Boiler blowdown tanks 1

[sophyl]

Is a blowdown tank required for a 20 bhp 100 psi boiler required by the ASME? Installer says that it can be blown down into a pail and the water than dumped provided the temperature of the water is under 180 deg.

 

[TD2K]

I wouldn't want to blow down 100 psig water from a boiler into a bucket unles the flow rate is very low and even then, you will have lots of flash steam. About 13% of the water will flash to steam on a mass basis and a much higher volumetric basis. Blow down very hard and there won't be any water in that bucket to worry about disposing, it will be over everything in the vincinity.

Can you let us know what type of boiler is it? I'd suspect small firetube or an electric? Is this blowdown intended to just reduce the TDS in the water or is it intended to removed an settled solids? What is the blowdown flow rate?

 

[sophyl]

The boiler is operated at 80 psi and is used in the manufacture of creams. Blowdown is daily to eleiminate sediment.

 

[TD2K]

I just realized I'm this site's top expert, that's scary given I'm a chemical engineer . How did this happen?

First, I doubt the ASME code requires a blow down vessel though it would likely govern the design if you selected one. There may be other regulatory bodies that might, this is way outside my area of knowledge.

However, I doubt I would want to blow this boiler into a bucket from an operating and safety point of view. Ask the manufacturer for a user reasonably near you (if one is available) that you can go visit and watch. At the least, phone a user and talk to them how they do it and then what you want. Sorry, I know this isn't the most specific advise.

 

[TD2K]

Ah, I see now, the Taylor Forge bulletin did it. Whew, that's a relief.

 

[ExAI]

The use of a blow down tank is purely a Jurisdictional consideration. Its a safety and environmental issue only. Lane Baker
Baker Quality Services
LaneBQS@att.net