Ribbon burner questions

[natenaaron]

I've been reading thread after thread about ribbon burners here and elsewhere, but not finding the answers.

1-Does altitude have an effect on a ribbon burner's efficiency and blower pressure?

2-Can an air compressor, Plumbed 60 gallon tank, be used as a blower?  If not why not?

3- Frosty mentions in a recent thread using raft pumps.  I have never seen any that have CFMs on them are these large river running rafts or the smaller toy rafts kids play on lakes and ponds with?

The reason I am asking is I have enough refractory to make several and since I am rebuilding my forge I might as well look into this.

[timgunn1962]

Huge caveat to start: I've yet to try a ribbon burner. The following is based on my understanding of burners, fans, compressors, etc and I am sadly not infallible.

1/ Altitude affects blower pressure and the density of the forge atmosphere. I think this will mean that a given forge heating a given workpiece at different altitudes will heat it slower, higher up. The maximum temperature should not be greatly different though. I don't think the effect will be significantly different between N.A. burners, blown burners and ribbon burners.

2/ An air compressor probably can be used but is a poor choice. A good compressor will usually give somewhere in the region of 4 CFM per HP on a good day. Compressing up to maybe 80 PSI to drop the pressure to perhaps 10" WC is very wasteful of energy.

3/ Suppliers CFM figures tend to be very misleading. Where given for a fan or blower, they are usually the maximum flow at zero pressure. Where given, pressures are usually the maximum pressure at zero flow. We tend to need some value of flow (CFM) at some pressure and unless the graph showing the relationship between flow and pressure (the curve) is available, we have no idea whether the fan in question can meet the duty.

Burning Propane with air, I calculated that each CFM of air will burn with between 0.3 lb/hr (to CO2) and 0.44 lb/hr (to CO) of Propane.

I did the same sort of calculation for Carbon (coal/charcoal) and Methane (Natural Gas).

If anyone wants to check the calculation, it is attached. If I've loused it up, please feel free to tell me so (I'm not sure I believe the numbers I'm getting TBH).

 

Calculation of heat produced and fuel used by burning with air.ods

[ThomasPowers]

My experience with a ribbon burner was using another's smith's forge at 7000'  I was working a piece of 2.5" square stock about 2' long.  This ribbon burner powered forge got that chunk to forge welding temps I know as another person sharing the forge accidentally forge welded a piece of 3/4" rod to my piece by sliding it along mine---we had to sledge it off to get it unstuck.  No flux, no hammering, just slid it along in contact.

Why not?  First tell me why you don't fill swimming pools with hypodermic needles---the needle will shoot water farther than a hose will after all! Or to put it a different way---why not put wear and tear on items that are expensive and have a limited life span and don't do as good a job as other things that are cheaper and easily sourced?  I would suggest getting friendly with an HVAC company in your location and ask about the exhaust assist blowers from ultra efficient furnaces; should be able to get them free off the bone pile.

Altitude always has an effect which is why supercharging was used on old prop planes.

[Frosty]

Ribbon burners are gun burners, air is supplied by a blower or super charger in engine parlance. It doesn't matter who's directions you follow, what parts you use or where you live. When you light it the first time or change the temperature you HAVE to ADJUST the air fuel ratio. Increase the fuel you MUST increase the air. Increase the air you MUST increase the fuel or visa versa. Same for changing altitude, the air is thinner so it can support less fuel and maintain a specified flame. Why do I say "Specified," instead of "Neutral," flame?  Because you may NOT want neutral or rich or oxidizing, it depends on what you're doing.

This isn't a bad thing it just is, unless you have the automatic control equipment installed in the system to do it for you.

Frosty The Lucky.

[natenaaron]

 

21 minutes ago, Frosty said:

It doesn't matter who's directions you follow, what parts you use or where you live. When you light it the first time or change the temperature you HAVE to ADJUST the air fuel ratio.

I understand this.

When people are talking about blowers are they talking about the kind used on coal forges?  Some folks were using squirrel cages but eventually moved to a "blower".  this type, this type, hair drier, mattress pump, leaf blower, or all of the above?  For me blower is too broad a term.  I am looking for an example.

 

[WayneCoeArtistBlacksmith]

I sure would not pay$500.00 for the blower.  The other one is a squirrel cage and will not develop pressure.  The type used to blow up Frosty (the snowman) or Santa Clause will do.  www.BlacksmithDepot.com  aka www.kayneandson.com sell the blowers that Grant Sarver sold.  I can't get the webpage up right now but the smaller one, I think sells for about $125.00.  Probably a hair dryer would work.  You could try the air compressor.  I have had smiths suggest that but I have not tried it.

Go to the Forge Supplies page at www.WayneCoeArtistBlacksmith.com and study the Ribbon Burner attachment.

You do have to have a tuff castable to make the ribbon burner.

Let me know if I can help you.

[natenaaron]

Thank you Wayne. I appreciate the guidance. I've been studying your ribbon burner for a few months now. I now have enough refractory to make one. I was stuck on the blower.

[DanielC]

For my ribbon burner I use the smallest Shop-Vac Lowes sells ($35) and pipe the exhaust to my plumbing. Its ~110 CFM and perfect for my ribbon. Can run it on rheostat, but I prefer to run it full blast, with a Tee and ball valve between it and the gas dump, to blow off the excess, as the Shopvac puts out more than enough. Plus if it burns out within a year, I can take it back and exchange it for a new one.

[jagboy69]

Hey Wayne... I sure could use your wisdom over at Another new forge build please..... 

Daniel... THANK YOU!  I have that exact little crappy vacuum too.  I am planning on using it.  ;-)

Jason

[natenaaron]

I always wondered what those little shop vacs were good for.

[timgunn1962]

12 hours ago, DanielC said:

For my ribbon burner I use the smallest Shop-Vac Lowes sells ($35) and pipe the exhaust to my plumbing. Its ~110 CFM and perfect for my ribbon. Can run it on rheostat, but I prefer to run it full blast, with a Tee and ball valve between it and the gas dump, to blow off the excess, as the Shopvac puts out more than enough. Plus if it burns out within a year, I can take it back and exchange it for a new one.

If you are blowing off the excess air, it's a really good idea to do it through an air curtain along the lines of the one that Wayne uses and Frosty recently started a thread about. 

[DanielC]

5 hours ago, timgunn1962 said:

If you are blowing off the excess air, it's a really good idea to do it through an air curtain along the lines of the one that Wayne uses and Frosty recently started a thread about. 

Splendid idea! When I get the atmosphere reducing, I can manage 2 feet of dragons breath. Tongs and handles are HOOOT.

17 hours ago, jagboy69 said:

Hey Wayne... I sure could use your wisdom over at Another new forge build please..... 

Daniel... THANK YOU!  I have that exact little crappy vacuum too.  I am planning on using it.  ;-)

Jason

You are welcome. Make sure it is clean inside, and no filters.