Which NFPA guide for power plants

[dickadams]

Hi,

I need to work out the quantity of water (gpm/ft2) needed for various power plant items (mainly FGD) which NFPA guide will tell me that?

The systems I hope to cover include an FGD absorber, slurry pumps, filtration plant, conveyors and limestone mills.

Dick Adams

 

[stookeyfpe]

What the heck is a FGD? fuel gas digester? Flatuence generating diverter?

I'm traveling on business but I am unaware of a NFPA standard for fossil fueled plants, if that is what you are speaking of.

 

[dickadams]

FGD is flue gas desulphurisation. It is a chemical plant attached to a power plant to clean up the flue gas prior to sending to the stack. It has a limestone reception building, crushers, mills, limestone slurry systems, a reactor (absorber) and gypsym slurry system, driers and gypsum storage. In other words it a regular chemical plant. I'm not expecting NFPA codes specific to power plant but would like some advise on which standard has water coverage rates.

Thanks

 

[rbulsara]

dickadams:

You will be better off posting your question on the Chemical Engineering /process design forum or Mechanical /piping forum.

NFPA is a fire safety standard or Code and is not meant to help design process water system. Your process decides how much water you need.

 

[stookeyfpe]

I think what he's looking for is application rates for water spray systems used to protect process equipment. I'm assuming that your seeking design criteria based on your particular process hazards or asset protection.

In this case you will need to review NFPA 15, which governs outdoor water spray systems.

I noted that your dealing with a great deal of limestone and gypsum. These materials are not a dust deflagration hazard and are not combustible. However, I understand that you be required by an insurer to protect certain large value assets. If the equipment is outdoors, apply NFPA 15. If it is indoors see NFPA 13.

 

[rbulsara]

stook:

that kinda now make sense..but OP needs to confirm his intent.

 

[dickadams]

Thanks, NFPA 15 it is. I will check it out.

 

[DavidCR]

In API 2030 (Application of Water Spray Systems for Fire Prot. the Petroleum industry), there are some values of gpm/ft2 that may help at least as an example. (It is much more descriptive than NFPA 15 and refers to it).

In NFPA 850 (Power plants) (which is a non mandatory standard) it will give you a base to size your water demands, briefly:

500 gpm for hoses + the gpms required for the protection systems involved in a design fire scenario, all this for two hours to obtain a design water volume. Also, the design water volume, must be refilled in les than 8 hours.

The fire design scenario should include the water demands of the sytems that sould operate simultaneously in a reasonable worst fire event, and refering to e.g. NFPA13, NFPA 11, NFPA 15, would include some values.

Note, for example, that the requirements of NFPA 13, 15, 11 includes some hose water demand, so it is a little confusing to deal with both standards (NFPA 13 and 850) to decide what is to be applied (to include the hose demand on the 500gpm or to add it?), so the AHJ must be consulted to decide.