DSM 1400 secondary inlet and outlets

Re: DSM 1400 secondary inlet and outlets

PostBy: Lightning On: Mon Dec 30, 2013 8:37 pm

lsayre wrote:But the pressure drop experienced by the draft pulling through the established bed of coal and ash is significant, vs. a minimal pressure drop through the secondary (over the fire) air openings.


Sometimes, I get a little thick :lol: I don't understand... :)
Could ya try that again?
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: DSM 1400 secondary inlet and outlets

PostBy: lsayre On: Mon Dec 30, 2013 8:46 pm

Lightning wrote:
lsayre wrote:But the pressure drop experienced by the draft pulling through the established bed of coal and ash is significant, vs. a minimal pressure drop through the secondary (over the fire) air openings.


Sometimes, I get a little thick :lol: I don't understand... :)
Could ya try that again?


Simultaneously measure your draft immediately above the stove and at (through) the ash door and see if there is a measured drop. Then see if the differential (drop) is even greater during wind gusts.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Anthracite Pea
Other Heating: Resistance Boiler (It has been fixed!)

Re: DSM 1400 secondary inlet and outlets

PostBy: Lightning On: Mon Dec 30, 2013 8:49 pm

lsayre wrote:Simultaneously measure your draft immediately above the stove and at (through) the ash door and see if there is a measured drop.


Yes sir, done that.. I've measured everywhere.. Before and after baro, above and below the coal bed thru the primary and secondary air controls.. All reading nearly the same. Below the grate is -.005 stronger than above the barometric damper. Believe it.. Or not... :lol:
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

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Re: DSM 1400 secondary inlet and outlets

PostBy: Lightning On: Mon Dec 30, 2013 8:51 pm

I'm still confused if you were implying that more air would come thru the secondary or thru the primary during a wind gust..
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: DSM 1400 secondary inlet and outlets

PostBy: lsayre On: Mon Dec 30, 2013 8:53 pm

Lightning wrote:I'm still confused if you were implying that more air would come thru the secondary or thru the primary during a wind gust..


And I'm confused by your manometer readings. That makes both of us confused. :?
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Anthracite Pea
Other Heating: Resistance Boiler (It has been fixed!)

Re: DSM 1400 secondary inlet and outlets

PostBy: Lightning On: Mon Dec 30, 2013 8:58 pm

lsayre wrote:And I'm confused by your manometer readings. That makes both of us confused.

I know it right!! Love this stuff.... :lol: It proves that pressure is nearly the same anywhere in the system and any change in pressure should dictate an equal change anywhere in the system INCLUDING volumes of air passing thru any openings no matter where they are in the cavity!! 8-)

That's my best guess :lol:
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: DSM 1400 secondary inlet and outlets

PostBy: lsayre On: Mon Dec 30, 2013 9:01 pm

Lightning wrote:
lsayre wrote:And I'm confused by your manometer readings. That makes both of us confused.

I know it right!! Love this stuff.... :lol: It proves that pressure is nearly the same anywhere in the system and any change in pressure should dictate an equal change anywhere in the system INCLUDING volumes of air passing thru any openings no matter where they are in the cavity!! 8-)

That's my best guess :lol:


I'm tempted to suggest breathing in through the open air and then breathing in (simulating draft) through a bed of coal ash to see which is easier to do, but I won't. ;) Warning, don't try this at home (or anywhere else)!
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Anthracite Pea
Other Heating: Resistance Boiler (It has been fixed!)

Re: DSM 1400 secondary inlet and outlets

PostBy: Lightning On: Mon Dec 30, 2013 9:06 pm

lsayre wrote:I'm tempted to suggest breathing in through the open air and then breathing in (simulating draft) through a bed of coal ash to see which is easier to do, but I won't.
I think the confusion is because people look at the coal bed as a restrictive object. Truth is, the little bit of air coming in the primary hardly notices the coal in the way at all, since the coal bed is just a huge pot of air passage ways.. At high volumes, sure it would slow it down, but dealing with the minute pressures and volumes in a coal bed, its un noticed.. Imagine blowing thru an air filter or blowing thru a Christmas tree. The only time the coal bed gets restricted enough to make a difference is when its completely clogged with ash. And at that point yer fire is goin bye bye..

That's why I see a -.005 stronger under the coal bed. It actually creates some of its own draft by heating the air that is coming up thru it. That's another best guess... :lol:

EDIT:
OK, the Christmas Tree was silly... Here's a more likely analogy... Imagine a gentle breeze oozing thru a screened window on a warm summer night. Is it likely the screen is slowing it down much? Would there be much difference in volume if the screen wasn't there? Probably not, right?

Then all of a sudden a thrashy thunderstorm moves in and a 60 MPH wind hits the screen. You here the screen whistle and click the light on to see it bowing inward. Is it likely the screen is slowing it down much? I would say yes. At high volume, the screen limits some air since its whistling and bowing are evidence. Would there be much difference if the screen wasn't there? I say yes again, since there is noticeable drag on the screen from a huge volume of air trying to get thru it.
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: DSM 1400 secondary inlet and outlets

PostBy: KingCoal On: Mon Dec 30, 2013 10:30 pm

i would only say that the "minute pressures and volume" traveling up thru the coal bed are in fact slowed by just enough of a degree to allow a head start to air coming in thru the secondaries.

look at it your way, neg. pressure is acting at the same degree everywhere over the coal bed including right on top of the secondary rail. is the restriction of the fire bed as slight as the wide open secondaries, i'm not convinced of that.
KingCoal
 
Hand Fed Coal Stove: Riteway # 37, Comforter Stove Works
Baseburners & Antiques: 2014 DTS C17 Base Burner
Coal Size/Type: Nut Anth.
Other Heating: none

Re: DSM 1400 secondary inlet and outlets

PostBy: oliver power On: Mon Dec 30, 2013 11:13 pm

oliver power wrote:
lsayre wrote:Before any of you go plugging things, perhaps a call to DS Machine is in order. The secondary air inlets were put there at a cost and for a reason.
I agree that the secondary air was put there at a cost. They must have a reason for adding the extra cost. I'm going to give you my opinion / guess. My first guess is for wind gusts. During a gust, the air is drawn from the path of least resistance, which is the secondary air tube. By drawing from the secondary air tube, metered air continues to be drawn up through the grates. This makes for a steadier fire, as well as keeping heat in the stove. Kind of acts as a built in, non-adjustable barometer damper. During periods of no wind gusts, the air flows up evenly across the entire width of the glass, acting as an air wash for the glass. Actually, the air film flowing between the door, and fire bed would also help keep the extreme heat off the door & glass when the stove is really cranking. I've seen other stoves with bolt on door frames, where extreme heat warped the metal, creating gaps between the bolt on door frame, and stove body. Don't forget, D.S. Machine has some really high BTU ratings, as compared to other hand fired stoves. Also, over the fire air would help ignite volitles (spelling?). Is this extra cost of the secondary air needed? Probably NOT. The E Z-Flow Hitzer's are great stoves, and they don't have secondary air. However, D.S. Machine must see more pro's than con's to this secondary air. The only con I can see would be if the chimney has a weak draft.
Well Lightnimg, I'm thinking you're right about air having little resistance through the coal bed, due to such a small volume. However, there is lots of resistance at the primary air control. The little bit of metered primary air, especially if using bi-metallic draft control, can't be much different (sometimes less) than the secondary air tube of the D.S. Machine stove. The secondary air, which is cooler/ heavier, and being pulled over the coal bed, I would think, would dampen the primary air some during a wind gust. Of course, this is all in fun theory.
oliver power
 
Stoker Coal Boiler: KEYSTOKER Kaa-2
Hand Fed Coal Stove: Hitzer 50-93 & 30-95, Vigilant (pre-Vigilant-II)
Baseburners & Antiques: MANY (Mostly when burning wood)
Stove/Furnace Make: HITZER / KEYSTOKER
Stove/Furnace Model: 50-93 & 30-95 , Kaa-2

Re: DSM 1400 secondary inlet and outlets

PostBy: CapeCoaler On: Tue Dec 31, 2013 12:17 am

Heated air thru fire bed expands...
Coal is burning at 1500* +...
Thus creating the pull to the ash pan below...
Now heated and expanded air is in fire box proper...
then cools...
secondaries easier path allow denser air in with more O2...
New burn then expands and rises up and out to vent pipe...
Slows on MPD...
then dawdles up chimney...
Hey i'm just guessin'...
But the burning coal pile must be responsible for the readings below the fire...
Pretty flames...
Blue Ladies...
Nice...
So Calming...
ZZZZ...
CapeCoaler
 
Stoker Coal Boiler: want AA130
Hand Fed Coal Stove: DS Machine BS#4, Harman MKII, Hitzer 503,...
Coal Size/Type: Pea/Nut/Stove

Re: DSM 1400 secondary inlet and outlets

PostBy: Lightning On: Tue Dec 31, 2013 3:56 am

CapeCoaler wrote:Pretty flames...
Blue Ladies...
Nice...
So Calming...
ZZZZ...


I think CapeCoaler is trying to hypnotize us....
:lol:

Actually, We could all be right... My mano readings taken under the fire show that the coal bed is not a restrictive object but instead it actually helps pull air in since the negative pressure is strongest at that location. But, that reading was taken with a healthy clean relatively ash free grate..

Later in the burn after some ash collects on the grate I agree that could be a different story. And the fact that during my first season of use, I discovered the bypass channels in the fire box liner, then stuffed insulation in them which showed HUGE improvement thru the burn cycle. Before that mod, its likely that negative pressure was stronger over the coal bed later in the burn which is where the "path of least resistance" cannibalizes my primary air pulling it around the coal bed. And for the sake of this argument, that's also when air would possibly be taken from the secondary air more easily than from the primary.

So there ya have it.. Is the coal bed a restrictive object?
I guess it depends on how well ash is cleared off the grate.. :D
I haven't tried taking a reading at the end of a burn cycle which may show that negative pressure is weaker under the coal bed than the pressure over it, at that point...
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: DSM 1400 secondary inlet and outlets

PostBy: oliver power On: Tue Dec 31, 2013 8:05 am

Lightning wrote:
CapeCoaler wrote:Pretty flames...
Blue Ladies...
Nice...
So Calming...
ZZZZ...


I think CapeCoaler is trying to hypnotize us....
:lol:

Actually, We could all be right... My mano readings taken under the fire show that the coal bed is not a restrictive object but instead it actually helps pull air in since the negative pressure is strongest at that location. But, that reading was taken with a healthy clean relatively ash free grate..

Later in the burn after some ash collects on the grate I agree that could be a different story. And the fact that during my first season of use, I discovered the bypass channels in the fire box liner, then stuffed insulation in them which showed HUGE improvement thru the burn cycle. Before that mod, its likely that negative pressure was stronger over the coal bed later in the burn which is where the "path of least resistance" cannibalizes my primary air pulling it around the coal bed. And for the sake of this argument, that's also when air would possibly be taken from the secondary air more easily than from the primary.

So there ya have it.. Is the coal bed a restrictive object?
I guess it depends on how well ash is cleared off the grate.. :D
I haven't tried taking a reading at the end of a burn cycle which may show that negative pressure is weaker under the coal bed than the pressure over it, at that point...
Look at Lightning go........... He's on a roll now...........Yes, variable restriction due to ash build up. Makes sense. Something we all knew, but took bouncing off each other to bring it out. It was a dealer who told me the D.S. Machine had longer burn time than the Hitzer 50-93 due to design. This dealer sells both Hitzer & D.S.. Maybe as the ash builds, more secondary air gets pulled in D.S. design, slowing the air through the coal bed. Results= longer burn. Where as the Hitzer always pulls the air through the coal bed. What do ya think??
oliver power
 
Stoker Coal Boiler: KEYSTOKER Kaa-2
Hand Fed Coal Stove: Hitzer 50-93 & 30-95, Vigilant (pre-Vigilant-II)
Baseburners & Antiques: MANY (Mostly when burning wood)
Stove/Furnace Make: HITZER / KEYSTOKER
Stove/Furnace Model: 50-93 & 30-95 , Kaa-2

Re: DSM 1400 secondary inlet and outlets

PostBy: KingCoal On: Tue Dec 31, 2013 10:57 am

i say a resounding yes, as ash builds and slows air movement thru the fire bed the flow above slows and more air comes in the secondaries.

i my experience with the DSM 1400, i use much more coal over a like time frame when the secondaries are blocked and all air must come up through the fire bed. that also means shorter burn time.
KingCoal
 
Hand Fed Coal Stove: Riteway # 37, Comforter Stove Works
Baseburners & Antiques: 2014 DTS C17 Base Burner
Coal Size/Type: Nut Anth.
Other Heating: none

Re: DSM 1400 secondary inlet and outlets

PostBy: franco b On: Tue Dec 31, 2013 11:35 am

KingCoal wrote:i my experience with the DSM 1400, i use much more coal over a like time frame when the secondaries are blocked and all air must come up through the fire bed. that also means shorter burn time.

You use more coal but produce more heat. If the thermostat were adjusted to compensate for equal stove temp. then I think burn time would be the same.
franco b
 
Hand Fed Coal Stove: V ermont Castings 2310, Franco Belge 262
Baseburners & Antiques: Glenwood Modern Oak 114
Coal Size/Type: nut and pea

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