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building my 1st roaster
sfloyd
Top  #26 Print Post
Posted on 12/25/2024 1:55 PM
Merry Christmas everyone
 
sfloyd
Top  #27 Print Post
Posted on 12/25/2024 3:35 PM

Quote

oldgrumpus wrote:

I may be misunderstanding how you're using the linear bearings with the square flange... a linear bearing is designed to slide on a shaft back and forth.

The pillow block bearings look OK, but they are sealed and greased. I used similar bearings, removed the seals and the grease, which enabled them to be subjected to heat.

The SS shaft looks good too.


I just read through your build post.... and I see now what was meant with letting the rear bearing float (just don't tighten down the back pillow block bearing set screws.... AND the proverbial light bulb just lit in my head, 2 pillow block bearings it is.

Are you saying you don't grease the bearings at all? If not, then i can still get different bearings.
 
Yasu
Top  #28 Print Post
Posted on 12/25/2024 6:48 PM
If the drum is driven by a timing belt
It would be good to use a timing belt to drive the drum, which would allow for misalignment due to expansion and contraction, and would not apply tension to the shaft.
I have a pillow block that slides on a bed.
It works well for maintenance and no heat transfer.
Yasu attached the following image:
2024-12-26_094159.png
Edited by Yasu on 12/25/2024 6:53 PM
 
sfloyd
Top  #29 Print Post
Posted on 12/25/2024 6:56 PM
The last few days I have been contemplating the burner/ heat control set up and what I think I have come up with is as follows and attached drawing

1) burner safety valve and pilot assembly I am getting this https://www.amazo...R&th=1 It is used for fire pits so my thought is it would give enough flow. It also has a valve on it

2) For the Burner as mentioned before is this one https://www.amazo...&psc=1 The line coming from the propane tank to the burner will be changed to enter into the safety valve then the output of the safety valve will get plumbed into the burner

3) The temp controller will be this one https://www.amazo...&psc=1 incorporating this thermocouple https://www.amazo...&psc=1 The thermocouple will go into the drum by about 1 inch

And now for the questions:
1) will 1 inch be far enough in the drum?
2) where in the drum should I pace it? Towards middle? I know it can't be exactly in the middle as thats where the shaft is.
3) What size valve for the solenoid valve? I was thinking of adapting to a 1/2" as the output of the safety valve is 7/16"-24 UNS.
4) Any other thoughts?



edited on 11/25 to post corrected drawing
sfloyd attached the following image:
gasheatcontrol2.jpg
Edited by sfloyd on 12/25/2024 8:02 PM
 
sfloyd
Top  #30 Print Post
Posted on 12/25/2024 7:11 PM
Hi Yasu,

Quote

Yasu wrote:

If the drum is driven by a timing belt
It would be good to use a timing belt to drive the drum, which would allow for misalignment due to expansion and contraction, and would not apply tension to the shaft.
I have a pillow block that slides on a bed.
It works well for maintenance and no heat transfer.



I see what you mean by the sliding now.... All kinds of light bulbs popping on now.

As to the misalignment due to expansion and contraction, Couldn't a lovejoy coupling be incorporated between the 2 shafts?

What size is that roaster?

Hope your holidays were good.
 
Yasu
Top  #31 Print Post
Posted on 12/25/2024 7:17 PM
Bypass lines with different flow rates as shown in the figure.
with different flow rates as shown in the figure.
Two circuits will be open.
Open main only
Open sub only
Fully closed
The flow can be controlled in 4 stages, so it can be controlled like a proportional valve.
I think it is possible to control with high accuracy later on.
Yasu attached the following image:
2024-12-26_101148.png
Edited by Yasu on 12/25/2024 7:30 PM
 
Yasu
Top  #32 Print Post
Posted on 12/25/2024 7:20 PM
Drum size will be 3kg
I usually bake with 2kg
(diameter 12in length 8in)
 
Yasu
Top  #33 Print Post
Posted on 12/25/2024 7:53 PM
The size of the drum may seem short in relation to the diameter, but we chose this size to reduce the effect of heat transfer even if the drum temperature rises at that time because we increase the heat profile at the end of the roasting process (from DRY to FC).
I wanted to make heat transfer <convective heat.
In sfloyd's case I don't think it matters since he prefers dark roast.
If you want to have heat transfer > convective heat, I think you should have a long drum in relation to the diameter.
If you can adjust the rotation speed,
When slow, heat transfer > convective heat When fast, heat transfer < convective heat
(This is just the speed at which the beans do not stick to the drum periphery...)
This is just my theory, and I am sure there are many opinions...
 
sfloyd
Top  #34 Print Post
Posted on 12/25/2024 7:57 PM

Quote

Yasu wrote:

Bypass lines with different flow rates as shown in the figure.
with different flow rates as shown in the figure.
Two circuits will be open.
Open main only
Open sub only
Fully closed
The flow can be controlled in 4 stages, so it can be controlled like a proportional valve.
I think it is possible to control with high accuracy later on.


my mistake on the drawing there is only one propane tank, the red lines were electrical connections. Sorry about that I forget to change wording on my copy and paste, uodated drawing attached here
sfloyd attached the following image:
gasheatcontrol_1.jpg
 
Yasu
Top  #35 Print Post
Posted on 12/25/2024 8:08 PM
I understand that part.
On top of that, you said you're going to set up a subline on the bypass this time.
I suggested that it would be easier to control.
If it is ON-OFF with one PID line, it will be 0%-100%, and if it is ON-OFF with one PID line, it will be 0%-100%.
The air temperature after combustion will rise and fall quite a bit, but it will be easy to control.

However, if the gas combustion is kept at 30-50% in the bypass, the air temperature can be controlled.
If the gas combustion is bypassed by 30-50%, the air temperature will be reduced and control will be easier.
 
sfloyd
Top  #36 Print Post
Posted on 12/25/2024 8:14 PM

Quote

Yasu wrote:

The size of the drum may seem short in relation to the diameter, but we chose this size to reduce the effect of heat transfer even if the drum temperature rises at that time because we increase the heat profile at the end of the roasting process (from DRY to FC).
I wanted to make heat transfer <convective heat.
In sfloyd's case I don't think it matters since he prefers dark roast.
If you want to have heat transfer > convective heat, I think you should have a long drum in relation to the diameter.
If you can adjust the rotation speed,
When slow, heat transfer > convective heat When fast, heat transfer < convective heat
(This is just the speed at which the beans do not stick to the drum periphery...)
This is just my theory, and I am sure there are many opinions...


Thanks for that info. The motor i will be using will have a speed control. I am actually eyeballing this one right now https://www.ebay....R_DY64uAZQ

Just not sure if it will have enough balls? What do you think?
 
sfloyd
Top  #37 Print Post
Posted on 12/25/2024 8:25 PM

Quote

Yasu wrote:

I understand that part.
On top of that, you said you're going to set up a subline on the bypass this time.
I suggested that it would be easier to control.
If it is ON-OFF with one PID line, it will be 0%-100%, and if it is ON-OFF with one PID line, it will be 0%-100%.
The air temperature after combustion will rise and fall quite a bit, but it will be easy to control.

However, if the gas combustion is kept at 30-50% in the bypass, the air temperature can be controlled.
If the gas combustion is bypassed by 30-50%, the air temperature will be reduced and control will be easier.


OK I see what you are saying. Install a bypass valve to keep a slight constant flame always. Only thing I see here though is it is defeating the safety feature. I guess I could always install a 2nd safety valve with throttled back propane going to it and teeing off the other one electrically
 
Yasu
Top  #38 Print Post
Posted on 12/25/2024 9:06 PM
I'd love to see a structural drawing of the whole thing.

Drum, drum cover, input port, exhaust system, burner, etc.
Cross-sectional structure (hand drawing would suffice)

I would appreciate it if you could show me the air flow with a few arrows on it.

If you do, I'm sure the folks on this forum will be able to tell you a lot.
 
sfloyd
Top  #39 Print Post
Posted on 12/25/2024 9:51 PM

Quote

Yasu wrote:

I'd love to see a structural drawing of the whole thing.

Drum, drum cover, input port, exhaust system, burner, etc.
Cross-sectional structure (hand drawing would suffice)

I would appreciate it if you could show me the air flow with a few arrows on it.

If you do, I'm sure the folks on this forum will be able to tell you a lot.


good idea, right now it's still in my head with the rest of the demons. I'll do a quick one now, but it may take me a few days as I'm headed to bed soon and back to work in the morning. Back to dealing with dryers that heat up to 150 C
 
sfloyd
Top  #40 Print Post
Posted on 12/26/2024 6:24 PM
Attached are views pried from my brain on roughly what I plan on my roaster looking like.. included are
1) Front plate -- Self explanatory
2) Inner View Behind Face Plate -- Internal view with the face plate removed
3) Side View looking into the interior. Red arrows show air flow... I was also contemplating inserting a deflector plate between the burner and the drum. Just not sure yet
sfloyd attached the following images:
innerviewbehindfaceplate.jpg frontplate.jpg sideview2.jpg
Edited by sfloyd on 12/26/2024 6:55 PM
 
Yasu
Top  #41 Print Post
Posted on 12/26/2024 11:04 PM
Thanks for the conceptual diagram.
I see you are planning a full-scale drum roaster.

I have just noticed,
I thought the BT sensor position was a little high.
　　Many roasting machines on the market have the position you described.
　　I think it would be better to put it on the door to measure temperature accurately even when roasting small quantities. I put it in the position as shown in the attachment.
　(on the side that lifts up the beans in the direction of drum rotation)
2.BT direct PID control is quite difficult and may control the temperature of ET.
At that time, I would like to open just a port to install the sensor at the place where the exhaust air velocity is the highest (center side).
3. I think it is a very good idea to put a shield wall between the burner and the drum.
At that time, if possible, it would be wonderful if the shield wall could be adjusted by sliding it, so that it can be used as a hot-air roasting machine when closed and as a heat-transfer roasting machine when open.
　(I have a short drum, but I put a stainless steel mesh between the burner and the drum to make it more like a hot air roaster.
Yasu attached the following image:
20241227-120513.png
 
sfloyd
Top  #42 Print Post
Posted on 12/28/2024 7:00 PM
been busy couple of days.... Got my autocad drawings done and ready to cut metal, Got my front and back plates and ordered the rest of my framing and the associated items. Decided on 1 x 3 rectangular window. drawings attached

11/29 changed face plate and added chute connection to face plate
sfloyd attached the following images:
door.jpg backplatecuts.jpg faceplatechute.jpg frontplatecuts.jpg
Edited by sfloyd on 12/29/2024 9:40 PM
 
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