Boiler makeup water guidelines

[babooman]

Hello,

I am trying to find some guidelines about the required analysis of the makeup water to boilers.

I know ASME or ABMA ones but they refer to the boiler feedwater or the boiler water, but not to the makeup water. Additionally I use EPRI TR-113692, but it doesn't make any difference for the makeup water depending on the boiler pressure, and in my case, it is a small boiler working at 650 psig, so I feel it can be too strict..

Thank you for the help.

 

[bimr]

The boiler manufacturer should give you guidelines. The requirement for makeup treatment will depend somewhat on your water supply analysis, the boiler application, and the manufacturer's guidelines.

As a minimum, you need zero soft water, something that is obtainable with a good quality water softening unit.

The 600 psi rating is close to the breakpoint between using a deimineralizer or water softener.

The link below provides some information as to the ASME guidelines:

http://ir.library.oregonstate.edu/x...d=93B6FE8449F770871DB52BFC181A09C5?sequence=1

As you can see, if your silica, alkalinity, or dissolved solids are high in your raw water, then you need to reduce these parameters. Otherwise, you will have to utilize high rates of boiler blowdown to keep these parameters in balance.

 

[ione]

Why have you to make a distinction between feed water and makeup water? Makeup water and condensate as well are incoming water used to feed the boiler.

http://www.lenntech.com/applications/process/boiler/boiler-feedwater-characteristics.htm

 

[babooman]

My question refers to a power plant. In these plants, the condensate coming from the condenser makes up most of the boiler feedwater and only a small percentage of the boiler feedwater (1-2% approx) comes from the make up.

Therefore my question is about how to define the quality of the make up water since the codes and standards always refer to the boiler feedwater quality. I guess that depending on the condensate quality, the make up water quality could vary, in order to achieve the required quality of boiler feedwater.

Thank you.

 

[bimr]

The quality of condensate depends on the type of boiler, the chemical program, and the type of condensate polisher.

The quality of the treated makeup water will vary somewhat based on the raw water quality and the water treatment scheme.

However, you are basically trying to produce ultrapure water with the makeup water treatment system.

 

[babooman]

Any recommendation/suggestion about books or papers that can help estimating the return condensate quality in a power plant?

 

[bimr]

You can find information on condensate polishing if you search the archives of the international water conference.

http://www.eswp.com/water/paper_archives.htm