Loring vs other roasters energy usage - Page 7

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
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Almico
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#61: Post by Almico » Aug 22, 2019, 11:30 pm

crunchybean wrote:The metal of my drum will be no hotter than the energy supplied to it. It is made of aluminum not glass, so the conductivity is higher and it's thermal capacity (ability to store heat) is lower. So the drum wall wont get hotter than the air temp. So the wall temp is dependent on the air temp which is still hotter than the beans...

I'll keep digging if you go in first. :)
The drum temp is dependent on the air temp. The average of the air temp inside and outside. It's easy to measure, just take an IR thermometer to the outside of the roast chamber. My bet is that it will be cooler than the air inside and, at some point, cooler than the beans themselves.

How am I doing?

crunchybean

#62: Post by crunchybean » replying to Almico » Aug 22, 2019, 11:56 pm

By inside/outside I am going to guess the outside the roaster environmental temp. Which is supposed to be negated by the computer algorithm and thermometer. However as well built the hardware of the Ikawa is, it is not flawless and will vary 1C temp by 10F or so, my weather ranges from 50F to 90'sF throughout the year. The drum itself is essentially buffered by an air gap from the casing of the actual roaster. I am unsure if there is insulation surrounding the drum.

Besides that, no the drum (when the roaster is running) will never be cooler than the beans. First the drum is preheated. But doesnt need to be because the aluminum with a lower thermal capacity and higher conductivity will always receive energy/heat more quickly than the beans. Also the air coming into the chamber starts at 150F and ends anywhere from 460F (or so) to 545F (or so). Since coffee 1C happens around 370F-380F and smokes around..400F. I can safely assume the drum is always hotter than the beans.

Goose, I'm pinned foward and can't reach the ejection handle...eject, eject, eject...

Rytopa

#63: Post by Rytopa » Aug 22, 2019, 11:59 pm

Loring/Fluid beds are 100% convective roasters, the heat is driven via hot air into the beans, the drum or roasting chamber is simply used to contain the beans, only the loring has moving drum to help agitate the beans for even roasting via the hot air.

I may be wrong about the Ikawa, UNLESS Ikawa roasting chamber has their own independent heating element which heats up the chamber directly which in turn conducts heat into the bean, which i highly doubt so.

devlin2427

#64: Post by devlin2427 » Aug 23, 2019, 1:05 am

The ikawa is a glorified popcorn popper which has the same issues, no actual bean temperature measurements and the way the agitation works it keeps the beans in contact with the hot metal throughout the roast. A well designed fluid bed can actually measure the bean temperature inside the roasting chamber since you can greatly reduce the amount of hot air influence on the thermocouple.

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AssafL

#65: Post by AssafL » Aug 23, 2019, 3:17 am

crunchybean wrote:Besides that, no the drum (when the roaster is running) will never be cooler than the beans. First the drum is preheated. But doesnt need to be because the aluminum with a lower thermal capacity and higher conductivity will always receive energy/heat more quickly than the beans.
The rationale doesn't add (for me at least). If the thermal conductivity is high and the thermal mass is low, once the humid beans touch the aluminium the aluminium will quickly give up the small amount of reserve energy it has and the temp would equalize. Like a saucier pan.

If it was a preheated wrought iron, or even better, ceramics It would be convincing that at least some part of the roast is "conduction". Until the high thermal mass drum gives up its heat. Like a steak skillet.

Some Roasters go so far as to use copper to make it even less conduction. But then they put a heater under it. Making it more conduction (like a pan bottom). I guess the concept of "drum" as referred to in coffee roasting isn't just a shape of a drum, but also heater configuration and materials.
Scraping away (slowly) at the tyranny of biases and dogma.

crunchybean

#66: Post by crunchybean » Aug 23, 2019, 7:51 am

If you sear a steak, can you touch the pan? Can you touch the steak. Even if you flip the steak to a new side of the pan. Which do you think will be hotter, the crust of the steak or the pan that made the crust that hot?

You brought up a good point but I think it moves in the oppposite direction. In this case the mass of the beans is quite high to the drums volume capacity. But since the contact time of one exact area is small and new hot air is constantly replenishing the energy lost or absorbed, both the beans and the drum are constantly increasing in temperature. The metal is easier to heat the beans have a vapor barrier to contend with and move in the direction of more conductive (easier to absorb energy) to less conductive (harder to absorb energy) throughout the roast.

Copper transfers heat with little resistance, and this less energy loss. High end pans with layered bottoms, the different metal compositions help with both absorbing, transporting and diffusing energy as quickly/efficiently and evenly as possible.

And so I ask: is a Lamborghini a glorified Honda Civic?

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AssafL

#67: Post by AssafL » Aug 23, 2019, 10:37 am

crunchybean wrote:If you sear a steak, can you touch the pan? Can you touch the steak. Even if you flip the steak to a new side of the pan. Which do you think will be hotter, the crust of the steak or the pan that made the crust that hot?
In a cast iron pan that is heated actively from the bottom - the pan will be hotter.

For sauce in a copper saucier (similar to the convection oven) they will be at similar temperatures. Much closer than the steak in a searing (cast iron) pan.
And so I ask: is a Lamborghini a glorified Honda Civic?
Yes it is. The Robert Bosch electronics give it a nice touch but it is still a car.

And the avocado green I saw once was really nice and wouldn't work on a Honda. Not sure why. Car colors are like fonts. They work or they don't.
Scraping away (slowly) at the tyranny of biases and dogma.

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yakster
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#68: Post by yakster » Aug 23, 2019, 11:10 am

I think the better analogy to the Ikawa is an air fryer not a pan.
-Chris

LMWDP # 272

crunchybean

#69: Post by crunchybean » replying to yakster » Aug 23, 2019, 11:19 am

Yes I agree, it is very easy in this roaster to forget that if you dont try and get more conduction in during the roast you are going to end up with meaty-bready-millard like roasts and blow out all the sweetness.

And is the reason why I stated that I think the formation of flavor is heavily dependent on which side of convection/conduction used. But Hoos states clearly, coffees can be roasted across all types of roasters to the same flavor profile as long as you know how to do it. So say we all.

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trumz

#70: Post by trumz » Sep 09, 2019, 9:04 am

This has been an interesting discution for me as a new Loring S7owner...

I'd just like to clarify that you can adjust the speed of the drum padles on the S7. The drum padle motor is controled via VFD and can easily be adjusted manualy. Infact, all four motors (drum padles, circulation fan, cooling tray fan and cooling tray arms) are controled via VFD. I haven't changed anything yet... maybe I'll start with the cooling tray :)