Heat ratings

[JavaB]

Re: Heat ratings

Sullo,

Ive seen a similar device..... a tall pyrex tube on top of a super popper (was in America somewhere...... But it still only did a relatively small volume of beans....)

The problem is (as I see it) you can get a high volume of air from all sorts of (expensive) fan units.... but getting enough heat into the air to raise it to 250C is almost impossible with electricity as the source..... the airflow from a heatgun is about the most you will get with air hot enough to roast beans using a 2000W electric heater for example.

Ive seen a design for one on the internet which used a large gas burner to heat the air.... the designer of this home roaster (which did about a kilo from memory) .... said the cost was many hundreds of US dollars (using second hand parts)- and that is the only design Ive ever found for a "home made" fluid bed roaster.

EDIT: as a thought you could check out the gas powered workshop heaters.... they combine a fan which produces quite a volume of air at a high velocity and has an inbuilt gas heater..... kind of like a super heat gun!!

[Sullo]

Re: Heat ratings

Nunu,
I very distantly vaguely recall something like that but for the life of me cant remember where or what it was.
Turbocharged air, thats the problem Im getting cant get the air movement Im after, temp I can get but only from metal,
dont spode you recall what that device was?

Many thanks

[nunu]

Re: Heat ratings

I remember seeing pyrex bread tubes attached to poppers with turbocharged fan motors and heating elements. Very tall roasting chamber and highly visible.

[JavaB]

Re: Heat ratings

The Corretto is a heat gun with a bread maker used to agitate the beans... see

http://coffeesnobs.com.au/YaBB.pl?num=1154442377

An idea from one of our CS members and it works brilliantly.... some have roasted 1kg with this method.

[Sullo]

Re: Heat ratings

Im trying to avoid dismantling the popper as its in high demand, but I can see having to purchase another one for this experiment.
Have to do a search on coretto dont know what that is. Also trying toi avoid modifying the bbq, I can get it to the right temperature but once I start it will be relagated to coffee dept, and we kinda like using it to cremate meat at present.
Decisions decisions....
Im off to bunnings...

[JavaB]

Re: Heat ratings

even easier would be just to buy an iroast but I know I will want to take it apart, so I play now so when I get one I dont do that.....

Mmmmmm...... maybe you could heavily modify a popcorn popper.... they are similar to an I-Roast.... both being fluid bed roasters...... or have a play with a Corretto.... also a sort of fluid bed and direct heat roaster combined....

[Sullo]

Re: Heat ratings

even easier would be just to buy an iroast but I know I will want to take it apart, so I play now so when I get one I dont do that.....

[Sullo]

Re: Heat ratings

yeah teh lil pyrex one has it but the one of the coffee pot doesnt have anything?
I was trying out an idea I had with a variable heat source, air heat witha swirly attachment to make a heat "air path" liked the idea of glass cos it was right size and could see results.
Probably safer at this stage to use metal, out to the 2 dollar shops!
It was to be a frankensteins creation iroast clone.
thanks JavaB

[JavaB]

Re: Heat ratings

Sullo,

If - and thats a big if - the base is made of genuine pyrex glass (will normally have the word "pyrex" moulded into the base or stencilled on the outside).... it can withstand 230C..... which is pretty close to what you want.... And that is a steady state temperature..... thermal shock (rapid change in temperature) is another consideration - and pyrex also rates well in that category.

If it is a lesser quality (and it may well be)..... then the maximum temperature is even lower.....

If in doubt ..... back to metal is safer!

[Sullo]

Do anyone know how I can source the maximum heat rating on something?
Example, the coffee pot at the base of a drop filter machine, I want to know how much heat that can handle ie 225 C for 7 minutes before exploding?
I recall years ago there used to be those glass vision saucepans that would be ideal but cant seem to source them, failing this im back to a metal one.
Yes Ive been out in the lab again....