Cramer
Junior Member
Posts: 129 
|
Post by Cramer on Jan 14, 2014 18:42:36 GMT -8
Any problem with casting a square feed tube transitioning to a round burn tunnel? The round burn tunnel would best match with the angled riser but a square feed tube would better hold sticks of wood I think. I don't recall ever seeing anyone doing this though so I wonder if there is a reason for it.
|
|
|
|
Post by satamax on Jan 14, 2014 22:19:52 GMT -8
It's been done many times, with brick burn tunel and feed, and metal heat risers.
|
|
Cramer
Junior Member
Posts: 129
|
Post by Cramer on Jan 15, 2014 16:08:44 GMT -8
I have seen many times a brick feed and burn tunnel transitioning to a round riser, I just don't ever recall seeing a round burn tunnel and riser and a square feed. I am assuming a 6X6 square FEED transitioning to a 6 round BURN TUNNEL and of course RISER would be okay since the 6X6 feed is not that much different in CSA to the tunnel.
I have been searching all day (on-line) for one of those risers like Matthew has but so far have been unable to find one. Matt, if you see this, could you let me know who your supplier was so that I might find out the manufacturer and see if they have a distributor in my area?
|
|
|
|
Post by matthewwalker on Jan 15, 2014 19:01:43 GMT -8
You'll need to use real world sourcing skills for this one Cramer. Pick up the phone and call local suppliers to industry. Here's a starting point, thanks to Mechartnik, who posted this source a while back. www.firebrickengineers.com/vacForm.asp |
|
|
|
Post by 2tranceform on Jan 15, 2014 19:05:10 GMT -8
You need to find a place that sells and/or installs refractory products (boiler, foundary, etc). I found a place in Nebraska that carries this stuff. They will also sell me ceramic blanket and boards by the foot. If I can find it here, it should be available just about anywhere. Finding them was a bit tricky and it was a 200 mile drive one way. www.globalspec.com/local/3721/NCwww.virginiacarolinarefractory.com/products.php... I searched for North Carolina Refractory. Good luck!  |
|
Cramer
Junior Member
Posts: 129
|
Post by Cramer on Jan 16, 2014 3:28:03 GMT -8
Thanks guys! There is a place in Raleigh NC (I called them and they had no idea) I found many refractory pipe insulation (none of their working temperatures were high enough. Maybe my search term was too specific but I have always been able to find whatever I needed near here by using Raleigh as the city in search. I will keep trying Because until I know my riser I can not make the mold.
|
|
|
|
Post by matthewwalker on Jan 16, 2014 10:37:13 GMT -8
You can also cast one from refractory and contain it within a 17 gallon drum for strength, or a wire mesh supported Superwool/rigidizer like Stephenson. There are lots of ways to skin this cat Cramer, don't get too hung up on this. Also, if you are asking about working temps and talking to the suppliers about properties, they aren't going to give you info that's relevant to your application. If you look at the formed ceramic riser thread you can see where folks go off track once they get some info from the suppliers. I think that is a mistake. We are experimenting here, and their experience is with very large industrial/commercial applications. As an example, the castable I use for my firebox they said absolutely no way it would hold up to wood abuse. They are used to industrial bio mass where the wood is loaded with a loader larger than my house. It holds up fine to 6lbs of fuel. Good luck.
|
|
Cramer
Junior Member
Posts: 129
|
Post by Cramer on Jan 16, 2014 16:05:36 GMT -8
Thanks Matt, I have actually been looking at different ways to "skin this cat". (I often wonder how the colloquialisms we use are regarded by our friends across the pond). I was able to speak with someone today who actually knows something. That was refreshing. In case anyone wants to know the technical name for those things you and Peter use they are called "vacuum formed insulating riser sleeve". There are two types of riser sleeve. There is the type you have and an exothermic one which creates heat while also maintaining the temperature of the poured metal resulting in fewer impurities reaching the casting. I don't know if you live in an area where there are foundries but the intended use for these is to insulate a "riser" which is the place where molten metal flows into a mold. The closest foundry to me is around 200 miles away which is the reason they are so difficult to find around here. Interesting stuff.
The helpful person at Joe Moore Company in Raleigh said he could quote one for me but they do not keep them in stock at his place. He asked that I send a "sketch up" file so that he knows exactly what I am looking for and even indicated that they could form the mold and pour and cure the burner and feed for me if I wanted. I know that would probably be costly but I figure it would not hurt to get a quote. He even offered their service to pour and cure my already made mold if I would like them to.
Not really hung up on it but I love researching things I know nothing about.
I will let y'all know about progress as it occurs but it may be a little while as I will need some time off my "regular" job to get it all fleshed out.
Back to the feed tube/burn tunnel question: Should one mold a square feed transitioning to a round tube maintaining the CSA of the tunnel or would it be okay (like square tunnel to round riser) to have a 6x6 feed attached to a 6 inch round tunnel? Never got a definite opinion on this yet and before making the mold it would be good to know. Thanks again!
Cramer
|
|
|
|
Post by 2tranceform on Jan 17, 2014 7:23:16 GMT -8
Back to the feed tube/burn tunnel question: Should one mold a square feed transitioning to a round tube maintaining the CSA of the tunnel or would it be okay (like square tunnel to round riser) to have a 6x6 feed attached to a 6 inch round tunnel? Never got a definite opinion on this yet and before making the mold it would be good to know. Thanks again! If I remember correctly, it is better to have a square/rectangular burn tunnel. I think I read it in the RMH book. Also, the optimized J-tube rocket that Dragon Heaters makes, utilizes a square burn tunnel. I am guessing that this makes it easier to disrupt the flow near the top of the burn tunnel for a more complete burn. The round burn tunnel would probably work. I am not sure how it would compare though. |
|
Cramer
Junior Member
Posts: 129
|
Post by Cramer on Jan 17, 2014 16:06:33 GMT -8
Thanks Trance. I think the burn tunnel will be round out of necessity because of the angled riser. I don't see a good way to have a square or rectangular burn tunnel turn to accept an angled riser. The question is the CSA of a square feed to a round tunnel. 6X6 feed or match the feed CSA to the CSA of the round tunnel?
|
|
|
|
Post by Donkey on Jan 18, 2014 0:59:00 GMT -8
Match the CSA. At the junction between square and round, you might need to cheat the bricks open a little to avoid bottle-neck.. Try it without first, right there might be a really good place for a slight pinch-point. You might use the Venturi created to draw in secondary air in some sort of p-channel/S-Portal type arrangement.
|
|
Cramer
Junior Member
Posts: 129
|
Post by Cramer on Jan 18, 2014 20:43:01 GMT -8
Thanks Donkey. Since the burner is going to be cast it should be no problem to have a smooth transition from square (with a CSA of a 6 in round) to round 6 inch. It will be a tough one to figure out how to incorporate a P-Channel and a trip wire into the round burn tunnel but I am sure that I can figure out just how to do that before the cast.
|
|
Cramer
Junior Member
Posts: 129
|
Post by Cramer on Jan 19, 2014 17:37:06 GMT -8
Looks like I am going to form my own riser. Just cannot find one with the correct inside diameter and length required. I am ordering 2" Cerablanket and rigidizer. I will coat both sides of the insulation blanket and form 2 half cylinders (6 inch ID, 10 inch OD) and dry them in a vacuum box using a vacuum pump that will pull to 500 microns with fresh oil. The two halves will be encased by a piece of 10 inch duct to hold them firmly together. Anyone see anything wrong with this plan?
|
|
|
|
Post by satamax on Jan 20, 2014 9:00:42 GMT -8
|
|
Cramer
Junior Member
Posts: 129
|
Post by Cramer on Jan 20, 2014 16:08:35 GMT -8
Hey Max, I recall it vaguely. That is a batch box though. Does it use the kind of riser I was talking about? Maybe you were going to post the thread and not just the sketchup?
|
|
