Peter van den Berg

Matt Todd wrote:

Gerry Parent wrote:Matt,  If that is your idea of a "cobbled door", then I'd probably just drool over what you would consider to be a proper door!  Great job!
If you have any construction photos of it, I'd love to see them.  Thanks.

I WISH! That's actually Peters door from his DSR2 development thread. I included it to kinda confirm/demonstrate what he meant by his text description. My own metalwork is a long way off from that level!

Thanks for the compliment Gerry, metalwork isn't one of my strong points, I actually dislike it but sometimes can't avoid. My wife complains now and then that I tend to become quite grumpy when I have done grinding and welding.

Scott Weinberg wrote:I have asked this question before on another forum your well versed on,  and that is just how close to the bell side can you get with the top flue opening of your DSR2?

My own experimental setup had the top front exhaust of the DSR2 about half an inch from the barrel's inside. I expected the barrel to be much hotter than the rest but it didn't turn out that way.

The open DSR2 was operated with a spark screen instead of a door, yes. That particular screen would let air through over an area of about 60% of the total door opening's surface. That is quite different from totally open, I have to admit. In case you don't have a suitable screen at hand a strip of fireproof material covering half of the opening would suffice. That is, placed vertically in such a way there's an open space left and right of it, each occupying a quarter of the opening. In my case, that yielded the best results.
Hmmm... Hope this is clear.

fraser stewart wrote:I have read it a few time. Im not sure how you come by 0.0176715 sq m

I had lots of difficulties to grab the concept of decimal calculation while in primary school.
The 150 mm diameter is equivalent to 15 cm, 1.5 dm or 0.15 m. The formula to calculate the area of a circle is pi R², isn't it? That makes the cross section area of a pipe with that diameter 17671.5 mm², 176.715 cm², 1.76715 dm² or 0.0176715 m², all the same but expressed in a different value. The decimal point shifts one place for lengths, two places for area (²) and three for volume (³) when transposing up or down one step. So, going up three steps from millimeter to meter for area is the same as deviding by 1000000.
Once the teacher explained the above rules to this little boy it started to dawn on me. Sufficient to say, I wasn't a quick learner back then.

A word of warning here regarding the chimney size. It might be that the csa of the chimney looks like it's perfect for an 8" system. In my opinion it isn't, due to aerodynamic behaviour in that same channel. The hot and fast streaming core will be quite narrow and the corners aren't helping a strong draft, rather the opposite.

In this part of Western Europe the chimney sweeps are using a century-old formula to determine what diameter a comparable round channel would be.
It goes as follows: take twice the width, multiplied by the length of the chimney's csa and divide that by the sum of the width and length. The result is the diameter of the equivalent round duct.

2xWxL / (W+L) = D

Conclusion would be: your chimney is comparable with a round duct of 6.4", aerodynamically-wise.
An 8" system-by-the-book won't run well on such a chimney size. Let alone coupled to a cyclone which gobbles up a substantial part of the draft energy anyway.

Andy Bhill wrote:I do have one question,  when the p traps are installed to induce air, have you tried one that would come out in the center of the secondary burn camber at the bottom?  The only reason I ask is due to what I know about car injection systems. The carburetor came first then there was throttle body fuel injection, then port fuel injection and now cars have direct port injection where fuel is delivered straight into the cylinder.

Good question, I'll try to provide an answer.
Yes, I did try feeding air directly into the riser. In fact, that was the point I started developing the floor channel. My red bell heater was set up to allow this type of modifications, the first try was a single rectangular duct at the bottom of the firebox  and tried that at different positions in front of the port, inside the riser and so on. None of those worked as well as the original overhead p-channel. Trying 4 different sizes of duct, twelve different combinations with vertical parts and so on, I came to the conclusion the best spot to introduce air at the moment is the top half of the port in front of the rear wall. In reality, I spent the entire first heating season testing a multitude of possibilties, quite a long list actually.

Overall difference as compared to car systems: injection (in cars) is done with fuel and air already mixed in the right proportions. In this batchrocket system mixing is done in the riser, helped by a whole lot of aggressive turbulence. Combustion is more or less taking place in every stage, although most of the power is generated in the afterburner area, i.e. the riser. In my opinion this heater core bears more resemblance to a wood gasifier although it doesn't sport a forced air distribution. It relies entirely on aerodynamics and under atmospheric pressure, that's why it looks so deceitfully simple.

Matt Todd wrote:Turns out the guy who designed this core (Peter Van Den Berg) was running a little 4 inch core for his tests in 55 gallon drums.

Not entirely correct, it happened to be a 5" system, quite tiny still.

fraser stewart wrote:Can anyone help me. I need to know what sheetrock plastic wrap is. I have googled but not reaching anything. Anyone know what this is and can send a link

Since you are in the Netherlands, try stucgaas. Knauf Gitex is one of those.

thomas rubino wrote:How hot is an 8" batch?

Just checked: measured 1173 ºC equals 2140 ºF in a 6" version. A larger one like 8" would top that up a bit, might be 2300 ºF tops inside, especially against the rear wall. No experience with even larger systems, sorry.

fraser stewart wrote:I made the secondary air intake a while ago. I think its based on peters sketch up model measurments  Tonight i will take it out and measure it and post it..

The p-channel is the same size rectangle duct throughout, the floor channel is not. It's possible that you've mixed up the properties of the p-channel and the floor channel.
It has happen before, have a look at this information, please note the 2019 modification.