Can you guys share which brand/model of blower you are having good luck with for Farb? Also how are you connecting from 3” to 2” pipe?  Is there a good way to reduce it?

FARB?  If you mean a fan/air ribbon burner it is wholly dependent on configuration of your forge, size, build, number of ports and construction of the burner, length and configuration of mixing chamber, number of fittings...  Currently I'm using a 140 CFM fan from Blacksmith depot, but my multiport burner outlet needs to be recast, so I've just got a more conventional SS flame retention outlet.  You may need to experiment to get what you want.  Remember it is always possible to turn down a blower, ride the fan curve, or dump some air, but if the blower is too small (either CFM or ESP) it is tough to make that up.

As regards a reduction connection I like fernco style concentric plumbing reducers for blower connection.  You get both a reducer and vibration isolation.  Available at most hardware stores.

That plumbing reducer is what I have for our sidedraft charcoal forge. It works better than anything I have dreamed up and reasonable in cost.

Yep, I thought Farb is Forced Air Ribbon Burner, versus Narb, Naturally Aspirated Ribbon Burner.

i started the Narb route, but found it hard to get going well, mainly because I didn’t follow the couple recipes provided verbatim.  I’ve taken a few months off due to the holiday and frustration.  I’m hoping adding a blower to the mix, will make it more adjustable for tuning it in.

My forge as I remember is about 400 cubic inches.  My ribbon burner is 4x9 with 80 1/2 holes.   My plan is to add the burner, change plumbing over to the common path with needle valve, air gate, and block holes as needed.

I’m great with over sizing the blower.  But the blowers often have cfm without static pressure information, so hence I’m looking for brand/models that have been successfully used.

Thanks

Unfortunately I haven't done enough experimentation with different multiport outlets to develop a formula for blower requirements. My gut says that if you have 400 CFM and at least 2"WG you should be fine with that scale of outlets, but you may need to test alternatives.  I've never run a ribbon burner with 1/2" holes. Can't imagine how you fit 80 into a standard brick. That's almost half the area of the brick and, unless I've bolluxed the calc in my head close to a 4" pipe equivalent.  I'd check with Charlie Correll who has been making these for some while. You likely have way too much burner for a 400 cubic inch forge.

Incidentally,  Charlie, who has been experimenting with these for some years (and sells the excellent Pine Ridge burner), notes that these burners are best used at full flow for peak output conditions.  They may not be ideal for turndown applications.  Likely he is advising against setting up a condition where you might get pre ignition. 

Any decent blower manufacturer or salesman should have at least a pressure/flow table, if not an actual fan curve.

Whoa, my bad.  I was clearly ready to sleep when I wrote that.  The ribbon burner is 80 1/8” Or .125” holes.  No clue how I typed 1/2.  Sorry about that.

Has anyone tried using a blower like this?