Help Please: Problem with Royal #5 Burner

[BobCommaThe]

Hey Everyone - this is my first post, sorry for it being a request for help.

I recently purchased a rebuilt Royal #5 roaster. The guy who did the refurb did an excellent cosmetic job, and fitted out the mechanical side wonderfully - the problem is he didn't really know anything about the burner, nor did he really care.

He fitted it with a setup to connect it to a propane tank, via a 30 psi regulator (with inline pressure gauge), and a size 60 propane orifice.

The thing fired up and got plenty hot at the front of the barrel, but i didn't have full combustion along the iron burner - basically the first 3 or 4 holes would have flames coming out, but i couldn't get the remainder of the burner to light.

I talked to a friend that works in HVAC who immediately diagnosed the issue as the orifice being too small. I emailed some people i know use a royal roaster, but didn't really get any help - just enthusiastic encouragement - which is nice, no doubt, but not the help i was looking for.

Ultimately I bought a bunch of different sized LP orifices, and just trial and errored it until i was able to get flames out of all of the holes in the burner - so, yay!

Now - the new problem that i have is that i can get the whole thing burning, but I'm getting temp readings north of 500 degrees at only 1 psi on my gauge. I actually intend to roast cocoa in the thing, so 500 is about the max temp i'm looking to reach, which means there's no real control to lower the gas as I'm reaching my highest temp at basically the lowest setting.

So, I'm looking for some help/advice on how to proceed here - i saw there have been several refurbs documented in the forums here - I'm hoping someone here can offer some guidance.

Thanks in advance everyone!

 

[topher]

I just reached out to a guy who did a great restoration job on his #5. Lets hope you got the message.

 

[Valentia]

Couple quick questions.. are you getting good clean blue flames? Is the 500 degree temp reading with the exhaust damper open from the roaster? How many rpms is your drum spinning? If your belt is too tight you might have insufficient airflow

 

[BobCommaThe]

Couple quick questions.. are you getting good clean blue flames? Is the 500 degree temp reading with the exhaust damper open from the roaster? How many rpms is your drum spinning? If your belt is too tight you might have insufficient airflow

Yes - good blue flames

500 degree reading is an average - with damper closed it ranges around 520, with it wide open, it can stabilize around 485 - this measured from a probe thermometer mounted to the stationary drum collet, and angled to where the bean mass would be during a roast.

Not sure the RPM's on the drum

Airflow seems significant - though, i suppose that's a relative assessment as I'm not measuring airflow in anyway.



I will note, I haven't actually roasted in the machine yet - that's a combination of available time, and need to roast. I am certain that i can get the job done in its current condition - just looking for some guidance on how others built their burners for these machines.

 

[Valentia]

Ok. I am only speaking for coffee roasting, where 65 rpm is pretty standard range. Higher rpms would help with moving the airflow. High Pressure propane should have an #61 orifice. Do you have a Control Valve orifice along with the PSI Adjustable regulator?