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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.

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.

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.

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...

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.

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.

Yasu wrote:

From the direction of this vane.
it appears to rotate the drum counterclockwise when viewed from the exit side.
(It's hard to see the angle of the vane, so I'm just going by what I see...)
However, the temperature sensor is on the left side toward the front, which seems to have opened on the side with fewer beans being roasted? (the side with no beans taken by the rotation)

Please check once.

oldgrumpus wrote:

I saw the photo of your drum earlier, but please tell more about it. What are you using for the drum, the material and thickness?