Sam or Mary Yancy on tue 13 jul 04
Elements lasted a long time - Worked in a heat treat plant when I was young. We used to machine and heat treat steel, and make is almost hard as diamonds (Rockwell 63) with a wear surface of about 1/8 inch thick. The furnaces (three) were about 10 ft across and about 12 ft deep on the outside. They were top loaded and had Crane supported lids about 1ft thick and 9ft in diameter mounted in a bed of sand on the perimeter. The kilns/ovens (circular) had about one foot of bricks on the outside, with the heating elements in a "w" fashion about one by two inches in thickness/ diameter. There were several of these in the furnace. Inside this setup was a stainless steel "pot" of about eight feet in diameter and about 10 ft deep. They were of course electrical powered. To caburize the loads we dropped (drip method) pure kerosene into the furnace after it reached 1000 degrees. Watching through a isinglass port would show the kerosene "flashing" when it hit the furnace heat. Had to wait
till 1000- degrees and remember to turn it off before quenching - else explosion - happened one time - blew a lid off. We heat treated up to 1900+ F degrees and held for about 12 hours, dropped down to 1500 F, pulled the load (manually - with the Crane and quenched it in a 50,000 gallon tank of moving oil. Was quite a "fire blast" when we did this. Had to wear asbestos suit and face/hood - and did this on our own (only one person - no help). Loads were about 1200 lbs. Bottom line is I worked there 4 years and we never replace a element, but had to replace one of the "stainless steel pots once due to cracking. I learned a lot - but now have breathing problems - due to ???. Sam in Daly City. P.S. Place was called California Press and Pellet Mills co - based in San Francisco.
My question, could we get carburization atmosphere by ''dropping" in a little kerosene in a pottery kiln???
Ivor and Olive Lewis on wed 14 jul 04
Dear Sam,
You might be thankful you were not using Cyanide as the Carburising
agent. This gives a double dose of hardening. Gives Iron Nitrides as
well as Iron Carbides in the steel.
Asbestos suiting. That sounds like it came out of the arc. Visited
Beldams factory in Co. Durham (UK) years ago. All the spinning and
weaving machinery was enclosed in airtight containers.
Ah, your question.
Nothing to stop you injecting whatever hydrocarbon you wish into your
kiln provided you take the necessary precautions. If you can exclude
air intake in some way or other then you reduce the chance of a stray
explosion.
I use my bottle gas. Close of the primary air at the burner and shut
down the secondary air. close the flue to a minimum. To save my own
health I have installed a pilot flame at the flue to burn of the gases
which discharge. I am cautious about Carbon Monoxide.
Take care of those "Bellows". You only have one set and new ones come
with a penalty clause.
Best regards,
Ivor Lewis.
Redhill,
S. Australia.
----- Original Message -----
From: "Sam or Mary Yancy"
To:
Sent: Wednesday, 14 July 2004 6:48
Subject: industrial oven elements and carburizing pottery
> Elements lasted a long time - Worked in a heat treat plant when I
was young. We used to machine and heat treat steel, and make is almost
hard as diamonds (Rockwell 63) with a wear surface of about 1/8 inch
thick. The furnaces (three) were about 10 ft across and about 12 ft
deep on the outside. They were top loaded and had Crane supported lids
about 1ft thick and 9ft in diameter mounted in a bed of sand on the
perimeter. The kilns/ovens (circular) had about one foot of bricks
on the outside, with the heating elements in a "w" fashion about one
by two inches in thickness/ diameter. There were several of these in
the furnace. Inside this setup was a stainless steel "pot" of about
eight feet in diameter and about 10 ft deep. They were of course
electrical powered. To caburize the loads we dropped (drip method)
pure kerosene into the furnace after it reached 1000 degrees. Watching
through a isinglass port would show the kerosene "flashing" when it
hit the furnace heat. Had to
> wait
> till 1000- degrees and remember to turn it off before quenching -
else explosion - happened one time - blew a lid off. We heat treated
up to 1900+ F degrees and held for about 12 hours, dropped down to
1500 F, pulled the load (manually - with the Crane and quenched it in
a 50,000 gallon tank of moving oil. Was quite a "fire blast" when we
did this. Had to wear asbestos suit and face/hood - and did this on
our own (only one person - no help). Loads were about 1200 lbs. Bottom
line is I worked there 4 years and we never replace a element, but had
to replace one of the "stainless steel pots once due to cracking. I
learned a lot - but now have breathing problems - due to ???. Sam in
Daly City. P.S. Place was called California Press and Pellet Mills
co - based in San Francisco.
>
> My question, could we get carburization atmosphere by ''dropping" in
a little kerosene in a pottery kiln???
>
>
______________________________________________________________________
________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your
subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
| |
|
