CraftWEB Hot Glass Talk  

Go Back   CraftWEB Hot Glass Talk > Hot Glass > Antiques & Classics

Reply
 
Thread Tools Display Modes
  #1  
Old 08-03-2010, 11:16 AM
Rollin Karg Rollin Karg is offline
Registered User
 
Join Date: Apr 2002
Location: Kechi, KS
Posts: 912
Rollin Karg is on a distinguished road
Moly cooling

A friend sent me a schematic of a European built Moly furnace. At that time we were changing a pot and doing some upgrades on one of our furnaces. I noticed that the cooling tubes on the schematic seemed to be metal and quite a lot larger than what we do here. It made for a nice uncluttered look.

It made me start thinking about this area and I decided to build a plenum with some 2" flexible tailpipe attached to it. This would allow us to aim the air flow at the element tops. I gathered up some parts and formulated a plan.Then I had to leave town.

When I got back my plans had been modified and my guys had come with a new and I think better approach. We installed one of these a few months ago and it seems to be working well. We did the second one last week and that's what these photos are about. Still a work in progress but I like how it's going.
The blower is from Grainger and costs I think $112. It puts out 463 CFM. If you stand at the edge of the furnace and look at the elements you can feel a nice little breeze on your face.
Attached Images
File Type: jpg P7290033-6.jpg (36.1 KB, 239 views)
File Type: jpg P7290003-1.jpg (38.6 KB, 227 views)
File Type: jpg P7290005-5.jpg (47.3 KB, 205 views)
File Type: jpg P8020052-3.jpg (43.7 KB, 214 views)
File Type: jpg P8020053-2.jpg (43.5 KB, 222 views)
Reply With Quote
  #2  
Old 08-03-2010, 11:33 AM
Steve Stadelman Steve Stadelman is offline
Registered User
 
Join Date: Jun 2002
Location: Portland oregon area
Posts: 3,724
Steve Stadelman is on a distinguished road
That is a really nice way to do that Rollin.
__________________
If all you wanted to do was express yourself artistically, you should have obtained a field watercolor set and a pad of acid-free paper. You chose a media with INFRASTRUCTURE baby!
Reply With Quote
  #3  
Old 08-03-2010, 12:14 PM
Rollin Karg Rollin Karg is offline
Registered User
 
Join Date: Apr 2002
Location: Kechi, KS
Posts: 912
Rollin Karg is on a distinguished road
Thanks boss !!
Reply With Quote
  #4  
Old 08-03-2010, 12:48 PM
Larry Cazes Larry Cazes is offline
Registered User
 
Join Date: Feb 2006
Location: San Jose, CA
Posts: 784
Larry Cazes is on a distinguished road
Nice manifold, Rollin. Very clean design.
Reply With Quote
  #5  
Old 08-03-2010, 02:10 PM
Charles Friedman Charles Friedman is offline
Registered User
 
Join Date: Apr 2002
Location: Seattle Wa
Posts: 518
Charles Friedman is on a distinguished road
Paint it all gray. It will help it disappear.
That seams like a bit too large of a blower.
But, if it works? it works.
__________________
"Glass will save the world from ourselfs" CharlesF
Reply With Quote
  #6  
Old 08-03-2010, 02:48 PM
Rollin Karg Rollin Karg is offline
Registered User
 
Join Date: Apr 2002
Location: Kechi, KS
Posts: 912
Rollin Karg is on a distinguished road
Quote:
Originally Posted by Charles Friedman View Post
That seams like a bit too large of a blower.
Yeah ,probably. I just took a guess at the size to start and at $112 I can't see I would saving much to downsize. I do think some reflective paint would be a good idea.
Reply With Quote
  #7  
Old 08-03-2010, 04:23 PM
Eben Horton Eben Horton is offline
Registered User
 
Join Date: Apr 2002
Location: Wakefield, RI
Posts: 3,950
Eben Horton is on a distinguished road
looks really nice, but is that actually cooling the top of your furnace along with the elements?
Reply With Quote
  #8  
Old 08-03-2010, 05:35 PM
Kenny Pieper Kenny Pieper is offline
Registered User
 
Join Date: Feb 2003
Location: Burnsville N.C.
Posts: 779
Kenny Pieper is on a distinguished road
Rollin I am curious. Have you found that Steve's way with the two washers welded to a tube that blows the air just on the top shaft of the element to be inadequate?
Reply With Quote
  #9  
Old 08-03-2010, 06:15 PM
Rollin Karg Rollin Karg is offline
Registered User
 
Join Date: Apr 2002
Location: Kechi, KS
Posts: 912
Rollin Karg is on a distinguished road
Eben, the way it's setup, all the air is directed at the top of the elements and I can't see it having much impact on the overall temp of the furnace. The European unit had the airflow coming down from the top and I think that might have a small impact.

Kenny, I'm getting more air where I want it and I don't have hoses to deal with, so this what I like about it. The other way works, but I think this is a little better. We're using four furnaces right now and that's a lot of hoses. Plus with this system the top of the element is a little less cluttered. I don't see this an earth shaking improvment, but I think it's a little better.
Reply With Quote
  #10  
Old 08-03-2010, 10:16 PM
Scott Garrelts
Guest
 
Posts: n/a
looks like it should be a lot easier to change out a broken element. :crossing fingers:

plastic hoses melt, sheet metal usually doesnt.

i like it
Reply With Quote
  #11  
Old 08-04-2010, 12:00 AM
Steve Stadelman Steve Stadelman is offline
Registered User
 
Join Date: Jun 2002
Location: Portland oregon area
Posts: 3,724
Steve Stadelman is on a distinguished road
I think that this is a really good way to do this, i started using hoses because I got it out of the kanthal super handbook. There are lots of ways to skin a cat and keeping the transition from the strap to the heater is what is important.
__________________
If all you wanted to do was express yourself artistically, you should have obtained a field watercolor set and a pad of acid-free paper. You chose a media with INFRASTRUCTURE baby!
Reply With Quote
  #12  
Old 08-04-2010, 06:17 AM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 19,338
Pete VanderLaan is on a distinguished road
It does look good. I would again stress that cooling the leads at your transformer is a place where you can prevent a lot of serious damage. I have a blower running there whenever I go to High Fire.
__________________
Where are we going and why am I in this basket?
Reply With Quote
  #13  
Old 08-04-2010, 02:37 PM
Jon Myers's Avatar
Jon Myers Jon Myers is offline
Registered User
 
Join Date: Apr 2002
Location: Portland OR
Posts: 622
Jon Myers is on a distinguished road
That looks good Rollin, how much insulation do you run on the top of your furnace?
Reply With Quote
  #14  
Old 08-04-2010, 03:33 PM
Lawrence Ruskin Lawrence Ruskin is offline
Registered User
 
Join Date: Sep 2006
Location: Lions Bay B.C.
Posts: 706
Lawrence Ruskin is on a distinguished road
How much insulation do you run on the sides?

In my opinion, as a guy who used to insulate his SiC furnace with 18 '' of fiber all 'round, the Stadelmelter is under insulated.

I think a combination of Steve's ideas and the Electroglass furnace, is where the furture of the electric furnace is going.

An ovel crucible is easier to gather from and the glass sits closer to the elements.

The door mounted from below as in Electroglass leaves more room to insulate the sides.

A thermal engineer I know told me that heat flows like water going down a stream. If it hits a rock, it flows around it.If heat hits a barrier, (insulation) it will flow to and through the area of lesser insulation.

So if you have 10'' on top and 2'' on the sides, guess where the heat is going to go...
Reply With Quote
  #15  
Old 08-04-2010, 03:44 PM
Eben Horton Eben Horton is offline
Registered User
 
Join Date: Apr 2002
Location: Wakefield, RI
Posts: 3,950
Eben Horton is on a distinguished road
if you have 18 inches of fiber, your actually paying to heat up the last 9 to 8 inches of insulation when you turn your furnace up due to conduction.
Reply With Quote
  #16  
Old 08-04-2010, 04:41 PM
Scott Novota's Avatar
Scott Novota Scott Novota is offline
AbbyNormal User
 
Join Date: Jan 2004
Location: Pensacola Florida
Posts: 2,071
Scott Novota is on a distinguished road
Eben,


Are you saying that anything out more than 9 inches of fiber? IE> after 9 inches of fiber it does you no good.


Am I reading this right?


Scott.
.
Reply With Quote
  #17  
Old 08-04-2010, 04:55 PM
Eben Horton Eben Horton is offline
Registered User
 
Join Date: Apr 2002
Location: Wakefield, RI
Posts: 3,950
Eben Horton is on a distinguished road
Quote:
Originally Posted by Scott Novota View Post
Eben,


Are you saying that anything out more than 9 inches of fiber? IE> after 9 inches of fiber it does you no good.


Am I reading this right?


Scott.
.
I believe so. especially when you turn up to charge. the outer layers will draw heat out from the core due to conduction.

This is why most furnaces have 8 inches of fiber and not 15
Reply With Quote
  #18  
Old 08-04-2010, 05:53 PM
Jeff Thompson Jeff Thompson is offline
Registered User
 
Join Date: May 2004
Location: Bend, OR
Posts: 272
Jeff Thompson is on a distinguished road
If you increase the insulation from from 8" to 15", you've increased the surface area of the exterior of the furnace so much that like Eben says, it's conducting the heat away from the furnace. Under or over insulated in no good, it's the Goldie-locks syndrome.
Reply With Quote
  #19  
Old 08-04-2010, 06:22 PM
Larry Cazes Larry Cazes is offline
Registered User
 
Join Date: Feb 2006
Location: San Jose, CA
Posts: 784
Larry Cazes is on a distinguished road
Quote:
Originally Posted by Eben Horton View Post
if you have 18 inches of fiber, your actually paying to heat up the last 9 to 8 inches of insulation when you turn your furnace up due to conduction.
Eben, I agree in concept. How have you determined that 8" is optimum? Theoretical data or just by experience?
Reply With Quote
  #20  
Old 08-04-2010, 06:22 PM
Paul Hayworth Paul Hayworth is offline
Registered User
 
Join Date: Jun 2002
Location: Port Macquarie
Posts: 151
Paul Hayworth is on a distinguished road
steel flex piping for cold air

http://www.gsl.cz/en/products/pot-furnaces.html
Reply With Quote
  #21  
Old 08-04-2010, 06:42 PM
Eben Horton Eben Horton is offline
Registered User
 
Join Date: Apr 2002
Location: Wakefield, RI
Posts: 3,950
Eben Horton is on a distinguished road
Quote:
Originally Posted by Larry Cazes View Post
Eben, I agree in concept. How have you determined that 8" is optimum? Theoretical data or just by experience?
I am not sure- its sort of the industry standard in glass furnaces- Hub, wetdog, etc....
Reply With Quote
  #22  
Old 08-04-2010, 07:11 PM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 19,338
Pete VanderLaan is on a distinguished road
I recommend 8 inches as well and I documented the diminishing returns on insulating about ten years ago. I set a furnace at a floating temp with fixed settings. I kept adding insulation and the temps kept going up with the fuel input constant. After eight inches, it stopped changing. It didn't drop after 12 inches, it just didn't change at all.

Enough?
__________________
Where are we going and why am I in this basket?
Reply With Quote
  #23  
Old 08-04-2010, 08:05 PM
Eben Horton Eben Horton is offline
Registered User
 
Join Date: Apr 2002
Location: Wakefield, RI
Posts: 3,950
Eben Horton is on a distinguished road
Quote:
Originally Posted by Pete VanderLaan View Post
I recommend 8 inches as well and I documented the diminishing returns on insulating about ten years ago. I set a furnace at a floating temp with fixed settings. I kept adding insulation and the temps kept going up with the fuel input constant. After eight inches, it stopped changing. It didn't drop after 12 inches, it just didn't change at all.

Enough?
And.. if you stuck a thermocouple in the insulation at 8 inches, you would see that the tempature of the insulation would in increase dramaticly as you added more and more. So, when you are idling at 2000 and turn the furnace up to charge, you would have to heat up all of that hot insulation..
Reply With Quote
  #24  
Old 08-04-2010, 08:18 PM
Edward Skeels Edward Skeels is offline
Hotshop Warlord
 
Join Date: Mar 2007
Location: St Louis
Posts: 270
Edward Skeels is on a distinguished road
Quote:
Originally Posted by Eben Horton View Post
And.. if you stuck a thermocouple in the insulation at 8 inches, you would see that the tempature of the insulation would in increase dramaticly as you added more and more. So, when you are idling at 2000 and turn the furnace up to charge, you would have to heat up all of that hot insulation..
No. Wrong.
Reply With Quote
  #25  
Old 08-04-2010, 08:32 PM
Eben Horton Eben Horton is offline
Registered User
 
Join Date: Apr 2002
Location: Wakefield, RI
Posts: 3,950
Eben Horton is on a distinguished road
no. right.
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Forum Jump


All times are GMT -5. The time now is 06:25 PM.


All published comments within these message boards are the opinions of its contributor and does not represent
the opinion(s) of the owner(s) of this website. Please see the Terms of Use file for more details.

Books to Help Artists Avoid Online Scams: Top 10 Email Scams | Social Media Scams

Powered by vBulletin® Version 3.7.2
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
CraftWEB.com. Opportunity Network. 2008. All Rights Reserved.