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Another 1.5kg or 3lb drum roaster from scratch
oldgrumpus
Excellent! I had totally misunderstood which bearing should "float". For some reason I thought it was the one furthest from the motor. Thanks for the clarification. I also appreciate you actually measuring your chain. I think it's a good choice. Maybe overkill, but better that way than too weak.
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
 
oldgrumpus
I've decided to try to make the vanes inside the drum resemble the way Diedrich did it. From the looks of it, I think there are 12 or 16 vanes set at about a 45 deg. angle. I started with a 1/8" x 1" cold-rolled flat bar and put it in our Hossfeld bender and attempted to bend it "the hard way". That actually a real metalworking term! The Hossfeld could do it but what you can't see in the picture is that it has a slight ripple.
oldgrumpus attached the following images:
img_0557.jpg diedrichdrumsmall.jpg

Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
 
oldgrumpus
So now it seems the easiest thing to do is cut out all the individual vanes. The first one I made with the Hossfeld was about the right length but needed more of a curve. Here are some progress photos. I first got the convex part right, then used layout fluid and a scribe to match the curve on the other side of the metal. Then it was cut by hand on a band saw.
oldgrumpus attached the following images:
img_0565.jpg img_0562.jpg img_0561.jpg

Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
 
oldgrumpus
This is a fun picture. It shows the Diedrich drum printed out to the left of my drum. Inside my drum (at the bottom) is the first vane. I tried to lay it out so the angle and lengh of mine look the same as the print out.
oldgrumpus attached the following image:
img_0566.jpg

Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
 
sversimo
Sounds like a fun project! I did some extensive testing the last 2 weeks on how to improve the beanflow in my roaster, and this is what I ended up with:
[img][/img]
sversimo attached the following image:
indretrommelnyliten.jpg
 
oldgrumpus
Well I'm back after shelving this project for over three years! It's been hectic, but now I'm ready to jump back in.

I'm working on the drum and have a bunch of questions and could use some expert advice.

Bean circulation pattern: I don't know anything about this. Do the beans stay evenly distributed along the length of the drum or are they forced to the front against the chute?

As they circulate, are they brought to the end of the drum then taken back to the other end, or is the process more random?

Is there a gap between the drum and the end piece that allows some particles to drop down? If so, then is there provision for cleaning below?

How much space should I leave between the drum and the outer cover?

Thanks Folks!!
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
 
allenb
Hi grump, good to have you back!
Here's a thread I participated in, dealing with drum vanes that may help with your questions. If it doesn't answer your specific questions, let us know and someone will lend a hand.

http://forum.home...rowstart=0

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
allenb

Quote

oldgrumpus wrote:

Well I'm back after shelving this project for over three years! It's been hectic, but now I'm ready to jump back in.

I'm working on the drum and have a bunch of questions and could use some expert advice.

Bean circulation pattern: I don't know anything about this. Do the beans stay evenly distributed along the length of the drum or are they forced to the front against the chute?

As they circulate, are they brought to the end of the drum then taken back to the other end, or is the process more random?

Forward vanes (attached to drum skin) are continually driving beans to the front face plate. The next set of vanes (closer to the shaft) drive the beans backward.

Is there a gap between the drum and the end piece that allows some particles to drop down? If so, then is there provision for cleaning below?

Yes, there's always a gap although very small, and some very small particles will drop down and you should allow a means to access this area to clean as often as necessary depending on how many lbs of coffee you're roasting per year.

How much space should I leave between the drum and the outer cover?

I typically leave around 1/32" to allow for drum expansion when heated. If you lock the front plate shaft bearing and leave the rear bearing floating, drum length growth from heating will primarily happen in the rearward direction.

Thanks Folks!!

1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
oldgrumpus
Thanks Allen!

So still need recommended space between drum and shroud/cover.

Also some new questions...

Sources for solenoid valves?

Should the shroud/cover be insulated? BBQ's aren't. Seems like it might be a nice touch but not a definite requirement.

Sources for ready made bean valve?

Source for viewing glass?

Drum-end with perforated metal... 1/4" perforated sheet metal is good?

Thanks All!!
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
 
oldgrumpus
In the past week I have ordered the titanium tube burner from sausagemaker.com, the pilot kit, thermocouple and LP orifice. On eBay, I purchased the same White Rodgers safety valve shown in the burner kit available on sausagemakers. Also on eBay I ordered the drum bearings. I am second guessing myself... Maybe a call to Maxitrol would be good even now. I suspect that they would help me figure out all the proper components needed between the propane tank and the burner which is something I don't fully understand. Maybe there are too many variables. I think I will call them next week. Still need the proportional gas valve and controls.
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
 
allenb

Quote

oldgrumpus wrote:

In the past week I have ordered the titanium tube burner from sausagemaker.com, the pilot kit, thermocouple and LP orifice. On eBay, I purchased the same White Rodgers safety valve shown in the burner kit available on sausagemakers. Also on eBay I ordered the drum bearings. I am second guessing myself... Maybe a call to Maxitrol would be good even now. I suspect that they would help me figure out all the proper components needed between the propane tank and the burner which is something I don't fully understand. Maybe there are too many variables. I think I will call them next week. Still need the proportional gas valve and controls.


You might be successful in getting guidance from Maxitrol on components between tank and burner but from my experience, they are less than forthcoming if the person asking the questions isn't fairly knowledgeable about combustion systems to start out with.

If you find them less than helpful, shoot your questions to us and we'll get you an answer. I've had to work with commercial burner systems including safety and igniter design recently so I can most likely steer you in the right direction.

Questions from previous post:
Space between drum and shroud cover? For a small roaster, go with at least 3/4" between drum and inner wall. Yes, use at least a small layer of high temp insulation (1/2" mineral wool) between inner wall and shroud cover.

Viewing glass:
http://www.mcmast...s/=1357cgh

Solenoid valves? Go with Kelly or Clippard
http://www.kpiweb...ducts.html
http://www.clippa...

Drum-end with perforated metal... 1/4" perforated sheet metal is good?
Too thick for no reason unless you'll be doing a single ended shaft design where the overhung load would create stress on the drum's back plate. For a standard drum design, 16 gauge should be fine.

Bean valve? The only ready-made options for this that I know of would be a blast gate type of valve which is a sheet metal sliding gate arrangement. But, would probably be too large to fit in with most small roaster designs (not elegant).

http://www.homede...lsrc=aw.ds

Keep us updated!
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
oldgrumpus
Thanks allenb! I REALLY need some expert advice on proper selection of the two components shown in the attached photo.
oldgrumpus attached the following image:
diag.jpg

Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
 
allenb
Hi Ralph,

This is timely as I'm in the process of trying to find an online store that can sell the Maxitrol M420H which works with LP at 11" H2O. I have a call into one of their distributors so give me a bit to receive a call back.

This valve is really the only modulating valve I've seen for controlling low pressure propane (11") that is affordable (less than $200) but it does require a maxitrol interface board unless you can send it a variable 0-20 VDC. I'm not sure what it will set you back but from memory it's less than $100. There are other companies selling valves for this application but are very expensive. Neither Clippard nor Kelly make a modulating valve that is able to pass a sufficient volume at that low of a pressure. They need at least a couple of psi.

In the meantime, you will need to find out what orifice size options there are for the titanium burner you ordered. This will tell us what LP pressure will be needed to produce the BTU output you'll want for your roaster.

What will you be using for control output to the modulating gas valve?

For a regulator, this would work for you:

https://www.amazo...06NKXJX6M3

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
oldgrumpus
Thanks Allen for the suggested tank regulator!

The Maxitol representative suggested using the EXA STAR Modulating E42 valve and the CV200 combination gas valve. The first thing I did was to see if these were available on eBay and elsewhere, eBay has some variants of the CV200 for reasonable prices but the EXA STAR can't be found there. In fact, I could not find it from any online source.

The CV200 is only available with electronic ignition, which would be great, but I'm a bit more comfortable with a pilot light. In order to make that a reality, I was told that the CV300, which is a bit larger, would be my choice.

As far as what I will use to control the modulating valve... I have not really thought that far ahead. I am open to suggestion, but my thinking was that I would vary the input voltage to the modulating valve with a knob and "upgrade" the roaster after using it manually for a while.
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
 
oldgrumpus
Here is a link to the Maxitrol modulating valve that was recommended by Maxitrol:
http://www.maxitr...7.2015.pdf
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
 
allenb
The EXA Star series would be perfect for our application as it doesn't require an interface board to allow receiving a typical PID controller output (0-10VDC, 4-20Ma) but this is supposedly only available to manufacturers for using on an end product. We can buy them as a replacement part at a huge markup but one would need to know what products use them.

I have some calls in to a couple of maxitrol distributors to see if we can get around this. It's a real sad state of affairs when you can buy one of these in France or Germany as a non-OEM but not here in the US where the dam things are made!

You won't need the CV200 safety valve with the way you'll be setting things up with the standing pilot.

Going manual for now is a good way to go. I always suggest for people to stay manual for as long as it takes to get a good handle on running their machine. Most of the time they end up staying manual after seeing how much easier it is to make changes in real time. I'll try and nail down suppliers and cost for the M420H and SC11-B-Selectra-Signal-Conditioner over the next few days and will post results.

Allen
Edited by allenb on 07/07/2016 5:42 PM
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
oldgrumpus
I usually find that eBay has the best prices for things I am looking for... if it's listed. Presently, the M420 has been listing for $90 USD. But since we are looking for the M420H and none are listed on eBay, the best price I could find was $122.95 at SupplyHouse.com (with free shipping) http://www.supply...ropane-gas
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
 
allenb
That's in the $ range I've found as well for the valve. It's unfortunate that the non-H model only has a maximum output of 7" H2O while the "H" models go up to 11".

It's possible that you could make the non-H valve work. I don't know of any reason why a modulation range of say 1.5" to 7" wouldn't do the job. You might give it a try if the price is quite a bit lower than at Supply House. If you have any problem getting the valve from Suppy House, Industrial Controls Distributors, LLC can sell them. I verified this yesterday and they also carry the SC11B interface board for around $80.
Industrial Controls site is not easy to find the valve with their search feature but they carry them in their line.

FYI, depending on what size orifice will be supplied with your burner, you might have to drill it to get the right BTU output but this is not difficult to do. Once you find out what size it is, we can run it through a BTU calc to see if it needs tweaking.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
allenb

Quote

As far as what I will use to control the modulating valve... I have not really thought that far ahead. I am open to suggestion, but my thinking was that I would vary the input voltage to the modulating valve with a knob and "upgrade" the roaster after using it manually for a while.


To control the M420 without the interface board you can use one of these to supply the manual "dial" control:

https://www.circu...5w-24.html

And, for the "dial" control use one of these:

http://www.ebay.c...1251584891

You can mount this as you would any variable pot through the sheet metal face of the controls area of your roaster and just add a control knob. With an input of 24 VDC you would top out at around 21 volts at full rotation which would be just right for the needs of the Maxitrol valve.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
oldgrumpus

Quote

With an input of 24 VDC you would top out at around 21 volts at full rotation which would be just right for the needs of the Maxitrol valve.


That is absolutely perfect.

But would the M420 deliver enough BTU's being a lower pressure valve than the M420H?
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
 
allenb
I just spoke with the Maxitrol rep for Colorado a few minutes ago and received some bad news. I had him decipher the Maxitrol min/max flow rate chart for me and it appears the lowest flow rate for the Selectra line is 5 cubic feet/hour which at 2500 btu/cubic foot comes to 12,500 btu/hour which is equivalent to 3600 watts. You'll need a lot less burner output than that at various stages of a roast in a 3 lb drum roaster.

He promised me he would do some more research and see if Maxitrol had any other valves that might have lower min flow rates.

It might be worth buying one and see if by using a lower input pressure (less than 11") you might be able to trick it into doing a lower min flow rate. That would require buying an adjustable regulator and I'm not aware of one that adjusts that low.

More research needed!

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
oldgrumpus

Quote

it appears the lowest flow rate for the Selectra line is 5 cubic feet/hour which at 2500 btu/cubic foot comes to 12,500 btu/hour which is equivalent to 3600 watts

Yes, that is bad news. If they can't find another solution, I'm not opposed to modulation using an array of several small solenoid operated valves. I have them on hand already as they are surplus that I obtained years ago.

Here's the info on the valves: Grainger still sells them. Not cheap, but for me they are free and I have more than enough of them for the project.
Ingersoll Rand CAT44p-012-D-G

https://www.grain...08194705:s

The image with the little green and red valve is a Numatics which I also have enough of for the project if they are a better choice. They are tiny which might work out even if used without an adjustment screw or needle valve.
oldgrumpus attached the following images:
img_2459.jpg img_2460.jpg img_2457.jpg img_2462.jpg

Edited by oldgrumpus on 07/08/2016 3:15 PM
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
 
allenb
I looked up the CV on the solenoid you linked to at Graingers which is .056. This will allow 5 cubic feet per hour at 1/2 psi so it will definitely handle the necessary flow rate.

If you decide to go the alternating two state (hi-lo flow), here's Lylabrown's test setup using one solenoid and two needle valves on a video he did a while back which should be very effective.

http://forum.home...post_51800

I would not cycle the solenoid faster than once every 2 seconds with a drum roaster. The coffee will never see a temp fluctuation at this cycle rate. If I were to build a roaster using this setup I would have the two needle valve knobs and pressure gauge mounted up front for easy access.

The solenoid he is using (Clippard ET-2-12-H) is able to cycle rapidly without overheating the coil but not sure how a standard solenoid as you have will tolerate it. If you have to buy one, they're not too expensive.

Question, are you set on eventually going the automation route? If not, I would seriously consider using a nice, high quality needle valve with appropriate CV value to work with 11" H2O and a good panel mount gauge and use it with your standing pilot/safety valve setup. This will give you optimum control with safety built-in and is how 99% of drum roaster users operate their roasters. As I'm sure you are aware, trying to automate a drum roaster in a profile following manner is nearly impossible due to the inherent hysteresis between heat source and beans.

I am most likely going to eventually get rid of my two-state valve setup and go to a nice Generant needle valve as I stopped datalogging and don't require the electronics anymore.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
allenb
The Ambex YM2 drum roaster uses the Maxitrol M420H and from what I'm seeing, most people don't roast more than a 4 lb batch in them which is close to the batch size you're aiming for. I can't see why the valve wouldn't work for your application if they work for a 2 kg batch.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
oldgrumpus

Quote

Question, are you set on eventually going the automation route? If not, I would seriously consider using a nice, high quality needle valve with appropriate CV value to work with 11" H2O and a good panel mount gauge and use it with your standing pilot/safety valve setup.

I think that has great appeal. I love the idea of a manual or analog setup for many reasons. Using the M420H certainly would have some advantages, but the setup described in the quote is so much simpler. Love it.

Quote


I can't see why the valve wouldn't work for your application if they work for a 2 kg batch.

Actually I was wondering if the M420 would work as opposed to the M420H because those can be had for about $30 less. But at this point the notion of a manual valve and gauge makes more sense to me.
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
 
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