'P-channel
This is the duct in the original design
which is dedicated to the secondary air supply. Simply constructed, it works solely due to the law of physics known as the Bernoulli principle.' I see you are on top of secondary now! How about simply ' This duct supplies the secondary air'
4: Cast core
This is a recent design (2015) with the firebox divided
in three parts. into
5: Cast core (sidewinder)
A design
which riser isn't situated behind the firebox but at the side instead,
which limits installation depth. 'where the' 'allowing a shallower depth'
1: Straight brick core
'Using a good layout and a suitable clay/sand mix this masonry version
is surely convenient to give this technology a try. ' How about 'is an easy way to test these principles for yourself' or somesuch.
'For example somewhere outside in the garden, in an open barn or such. Be very careful, the riser is able to spit flame so use chimney pipe to lead the gases outside when built under a roof. That being said, this core is also suitable to serve as a space heater when built as a permanently installment. Surrounded by a construction to shed and/or store the produced heat.' How about 'This can be done outdoors, in a barn or shed, anywhere that is convenient. A word of warning, the riser will likely have flames shooting out of the top, so use chimney pipe to vent when tested in enclosed spaces. It is not 'only' a convenient test bed, it is more than suitable for permanent use as the core for a space heater (the clay sand mix allows for easy disassembly after testing). As will be described later, space heaters take advantage of the ultra clean burn provided by these combustion units and are able to capture and store the heat produced.' (I am assuming you will describe the 'construction to shed and/or store the produced heat' later), and I think you are describing bells and such with those words.
P channel
'Due to the under pressure in the port there will never be smoke leakage through this duct during normal operation. Unless smoke is streaming out the main air inlet and all other crevices.'
A bit clunky...how about 'The same principle that causes the P channel to work, Bernoulli's principle, means the pressure within the system is lower than that outside. Hence no smoke will escape the P channel, indeed any other small cracks or the main air inlet itself. Conversely, if smoke does come out of the P channel, or main air inlet then it means there is something wrong in the system.'
This secondary air
need to be added to needs
The duct is being cooled by the incoming air so the life expectancy of common steel is
within a reasonable margin. Damage by corrosion in an
appliance which has been used for two seasons is barely visible. So, it would be wise never to shut off the p-channel during operation. It is suspected a larger wall thickness of the duct could promote quicker corrosion because the steel can't shed heat as fast as the thinner material. how about 'surprisingly long' 'space heater' or 'stove', appliance is not quite the right word
2: Straight brick core, octagon riser
The problem of the
unround riser is solved in the next design non round
'Such a disadvantage won't be in play when insulating fire bricks are used for this build.
Even insulating material arond the riser isn't necessary anymore.' Around. Did you mean to point out that the riser itself can be made of ISFB? If so, how about 'The higher mass won't be a problem if it is built out of insulating fire brick (either the whole construction or only the riser), indeed when the riser is built from insulating firebrick then there is no need for added insulation around the riser.' Choose which part you want depending on what you meant.
The small yellow triangles are in reality the same material, the different color is only there
for contrast. Construction of this core is different
as compared to the first brick design, the connection between firebox and riser is dissimilar. suggest 'for easy visualisation' simply 'from'
'Both possibilities do consist of whole bricks which are cut in exact halves under a 45 degrees angle to assemble two sides of the octagon.' I suggest 'Both use bricks that have been cut with a 45 degree angle to create equal sized 'halves' to form an octagon shape'
'With a fitting firebox of course, the scaling method still applies.' not quite sure what you mean here. Did you mean 'As always, the size of the octagon is scaled from the size of the firebox to be used'
? If not, then you will have to explain.
3: Straight cast core, 4 parts
This a tried and proven design,
already built quite a lot. Suggest '...proven design with quite a few successful examples around the world' or similar. A bit clunky as written.
The firebox will stay whole, after the cracks
are appeared nothing much will happen later on. have
Probably the cracks
itself will act as expansion joints, tension is released and the cracks won't grow anymore. themselves
'The octagon shape of the riser is chosen because the fill pieces sticked in the mold can be made with a table saw. The saw blade has to be tilt to 45 degrees and that's it.' A bit awkward. How about 'Not only is the octagon a preferred shape (a very good approximation to round) it is also easily formed when building a mold. A table saw set to 45 degrees will cut all of the pieces required. Careful use of a hand held electric saw with a fence/guide will also serve if a table saw is not available.'
Floor channel
This secondary air supply duct is quite different from the normal p-channel, it lies at the bottom in a trench and it is fed through the same inlet as the main air supply. It is a floor channel and as such a variant of Matt Walker's pre-port tube but the vertical part is shorter, square and less wide. As a consequence, the tube is less of an obstruction inside the firebox. On top of that the air is supplied
almost exclusively halfway the height of the port which in turn keeps the double vortex low in the riser on average. how about just 'halfway up the port'
The channel is made out of normal 2 mm thick steel rectangular
duct but against expectations showed after one winter of daily use very little corrosion. Suggest 'duct and has very little corrosion or deterioration after a year of daily use in a harsh northern hemisphere winter'. (assuming that your winters are harsh, dunno)
'The inside is cooled by the incoming air of course and the outside is situated in a place where during the burn an oxygen-frugal environment is created. Steel isn't able to corrode in the absence of oxygen.' How about 'The explanation for the lack of corrosion is that the inside of the duct is cooled by the incoming air whilst the duct itself is in the non-oxidising environment of this firebox (recall the low excess oxygen numbers from the testo measurements), steel will not corrode without oxygen.'
Will resume later today
? If not, then you will have to explain.