Exhaust Gas Calculations - Who Can Do Them? 2

[ProActive]

We are replacing 2 existing 6.5MBTU Boilers with 6 2MBTU 2 stage boilers. We would like to use the existing stack but have some concerns weather it will work properly. We need to know what the minimum amount of boiler stages we need on to create enough flow and if we will have condensation issues. We basically need a professional engineer to do exhaust gas calculations to determine if our design will work, and if so what are the appropriate operating parameters. Can anyone help us find someone with this?

 

[metengr]

ProActive;
Be careful. Have you checked with any large, reputable boiler manufacturer (B&W, AP, Foster Wheeler) or are you engineering this retrofit internally to your organization with help from an outside AE firm?

If it were me, I would directly contact a reputable boiler manufacturer that has design/fabricate/construct capability and either has or can get access to computer modeling systems to evaluate flue gas temperatures and drafts to retrofit an existing facility.

I would be hesitant to rely on an AE firm unless they have demonstrated experience in the Power Generation industry.

 

[ProActive]

Thanks for the response, We are using PK boilers. We have been in contact with them. They directed us to the local distributor, who in turn has not been much help. They have given us opinions but we are looking for something more definative. The design idea was proposed by one of the several bidding contractors. Before we deside on any course of action we want an unbiased professional opinion based on solid engineering principles. It is amazing to me how hard of a time I am having finding a company or individual who can help us.

 

[metengr]

OK. Since you are using a boiler manufacturer that can't help, you need to have a reputable engineering firm perform this activity.

Two of the AE firms that we have used are Black and Veatch and Sargent and Lundy. I am not formally endorsing these companies, just telling you that we had used them in the past. My only advice is that you need to make sure that the personnel they assign to perform this modeling have the proper experience - a PE credential alone will not suffice. Check references and past jobs before signing any contract!

There are smaller boiler modeling firms that have been started by former CE and B&W engineers. This could be an option for you, but again check references!!!

 

[kbs]

If you would like, I can e-mail you some stack capacity calculations. The only measurement you would need is stack pressure ("w.c.) and stack height and diameter. Also, PK makes a great condensing boiler around 2000mbtu. If that is the style you are using, condensation of the flue gases would not be a problem.

 

[ProActive]

Yes that would be great KBS. Thank you very much. We can use all the help we can get.

 

[kbs]

Send me an e-mail to bruce_stad@city.vancouver.bc.ca . Include any info you can and I'll send the appropriate calculations.

 

[jesfixit]

I'm working on a similar project on my job, concerning cooking ovens. We have one in use, we're getting another, and I'd like to use the same hole in the roof, which is an existing exhaust blower. I could use a variable-speed drive to control the exhaust blower to increase the capacity of the flue.

Is this a feasible plan? I'd be interested in the calculations mentioned.

 

[chicopee]

What is the minimum number of boilers that would be operating at any one time; what type of boiler (WT,FT or flow thru) and fuel?
What is the current temp at the breeching of the 2 original boilerS and what type of a stack do you have?