New Mercedes Benz E230 wood gas project

Projects
#108

Hi, Kristijan!

12.10.2017
Usually you have a brilliant perception of physical phenomena but now you seem to have had a bad night’s sleep…

When hot humidity-loaded gas is cooling down it will “eventually” come down to the dew point, becoming 100% wet. It has no straight connection to the boiling point of water. The absolute content g/m3 and temperature will rule where the dew point happens to appear (at normal pressure).

This only to motivate, a distancing position to have 100*C as any dry/wet “yardstick”.

Additionally, when starting up, with everything being cool and condensing
the warming up period is disastrous for an initially cold paper filter!

A well known case is DJ, as he (counter advise) thought that (cold at start) coolant water would dry the gas before going to a paper filter…

One opposite (taking advise) builder Fredrik Ek has never had any trouble with “structure clogging” of any paperfilter. Why is this?
After settling, full cooling and wet mattress chest cleaning the ALWAYS WET gas goes through a coaxial mantel around the outlet gas tube from the gasifier!

Fanning up lets the raw gas out directly after the coaxial heat exchanger, which gets automatically hot before ANY gas goes to the cleaning system and thereafter to the paper filter…

A cyclone would provide the same “first spot hot” opportunity!

A paper filter is the last of 3 – 4 cleaning stages, never earlier!!!

2 Likes
#109

Hi Max, l had a great sleep tonight actualy :smile:

Its my understanding that if keeping the gas at constant 100c it doesent matter what water content it has. The water is in a gas stage and thus shuld have no problem passing the paper filter.
My towel sack filter had no problem working in wet enviroments so it doesent matter if gas gets below 100c, but its above that temperature that culd cause failiure to the filter. Thats why l thod of incorporateig a water boiling thermostate.

Problem is, while l have room in the trunk, where l can hot filtrate, l havent got much room in the engine compartment for a cold filter and reheat paperfilter and stuff like that…

1 Like
#110

Hi, Kristijan!
12.10.2017

Wetting paper does not ask for “flowing and dropping wet”; both wood and paper become “humid-wet” before they become “dropping wet”…

That “humid wet” is enough to destroy a commercial paper filter if the relative humidity stays long above 90%.

However cool and condensing wet the gas gets during the cleaning stages, there is always a guaranteed hot surface inside the gasifier cyclone mantel (if you weld a mantel on it) to warm it up when the gas is useful for the motor.

I see that 3 gas transport routes under the car bottom is much to apply,

but keeping the planned and built cooler to wet cyclones needs no modification.
But to get back and forth from the wet cyclones to the trunk could? go along the right side of the bottom?
From the wet cyclones along the right side of the bottom to the trunk and there to the gasifier’s hot cyclone mantel.
That could be partly drawn (straight parts) coaxially.
Or the reheated gas could go the shorter route along the left side to the motor.
Filtering dry gas is a nice thing to aim at…

1 Like
#111

Hi Kristijan, instead of water cooled, how about adding fins to the pipe going up to the engine with a flex pipe over it. With a air scoop up in front under the car with a adjustable air intake flap feeding the flex pipe. With a temperature probe in the pipe you could adjust the air coming to the engine double cyclones filters during winter or summer temperatures. The flex pipe could be insalated or not. Just a early morning 06:30am, having a cup of coffee thought.
I really like you secondary nozzle air not being preheated idea. That could help keep the gasifier running cooler on harder pulls with more air demand.
Bob

1 Like
#112

Just read what Max is saying. You could also heat the pipe up with the engine using heat off your exhaust pipe if needed in winter months.
Bob

1 Like
#113

Sorry Max, I know you think I should post on my own thread but I am on subject. My plan is to tap hot gas off from the gas line between the cyclone and the cooling pipes. Thenadd that hot gas to the gas line after the cooling and before a paper filter and then from that filter on to the engine.

3 Likes
Tom Collins' Gasifier
#114

Hi, Tom!
12.10.2017

That’s a half-breed, feeble way getting half way results. Under all circumstances the paper filter will work better if done properly. So does the motor too.
Less humidity = room for more oxygen.
Descriptions have been repeated many a time.

Complete condensation and complete reheating give complete results within reasonable effort.

2 Likes
#115

Yes Max what I am suggesting is a half-assed solution but is something more that most are doing. They are having burnouts in their intake manifolds because their process ends at a hay filter.
The quote above is very open door. What is “complete condensation”? A DP of 32 F or -460F? Or just zero moisture in the gas?
And complete reheating? Is there some temperature at which gas can not be heated any higher?
And yes finally, " with reasonable effort". If it could be done with reasonable effort I would think every one would be doing it like the hay filter. Sorry if I sound rude but as usual I read but don’t understand. TomC

1 Like
#116

Many good ideas to digest.

No dubt, Maxs way is best. If anyone has enough room (pickup bed) this is the way l wuld go. Woodgasing a sedan… its like threading a sewing neadle with bull rope sometimes.

Tom, didnt we discuss your idea before somewhere? I think its a reasonably good alternative to Maxs complete plan.

The thing is, Max says cool/condense the gas as much as possible. Then, slightly reheat the gas and send to the paper filter. This way clean, and dry gas is acheaved.
In your way, your main gas line will be cool and condensed, but wet. You will then add hot, but allso wery moist raw gas. This is unwanted becouse this is the moisture you will not get rid of.

Well l managed to make the condenseing hopper today, nearly finished, and the hopper lid seal so if all goes well, l might flare a bit tomorow!

4 Likes
#117

Hi, Tom!

12.10.2017
In this context, “complete” means whole the flow instead of part flow!
Reason again.

Making a coaxial heat-exchanger for whole the gas-stream is not a harder effort than welding a reheating mantle around a cyclone, or what?
Is it not reasonable?

I hope to read a reasonable answer on your page.

1 Like
#118

Thanks again for the words of encouragement Bob.

I know this is off topic, but I always very suprised and kinda sad when I have someone retire and they say “I just don’t know what I’m going to do now” and they’re being serious. I probably have 20 big projects to do right off the bat. Overhaul 3 or 4 antique tractors, convert them to woodgas, build fence, buy cattle, set up another sawmill and build, then run everything off grid with woodgas. Just get a little frustrated at times. At least I have the Dakota up and running great again, another big thanks to SteveU. I know one thing for sure, like you, I will never be bored when I retire…

Bryan

6 Likes
#119

Hey Kristijan, couple questions.Yes I did present this idea to you before. How is it that Max’s gas is cool and condensed and you say mine is cool and condensed ,but wet? Yes the small amount of gas I am adding will have moisture but a lot of heat. The moisture will raise the DP temp. slightly. The extra heat from the added gas will lower the DP more. The net result will be a lower DP. That gas will go through the paper with less condensation. Finally, what do you mean by a ‘‘condensation tank’’? TomC

1 Like
#120

Hi, Kristijan!
13.10.2017

I am sorry jumping in when not asked, but I hope to enable Tom to ask you the right questions…

So, Tom!

The dew point temperature of a gas(mix) is dependent on the amount of water it has taken up, on the brink of saturation/condensation
(100% saturation) and visa versa; the amount of taken up water determines the dew point.

If a gas at high temperature is satisfied with water it is saturated and cannot take up any further water at that temperature.

The gas at that temperature is “on the borderline” between wet and dry.

If that gas is cooled down, it immediately gets over satisfied = wet, and starts giving off condense. (dropping water)

Again, if a satisfied gas = 100% wet is heated, it immediately starts to dry
= its ability to take up more water increases. (if given)

:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

Now, if anybody starts to cool down hot gas from a gasifier, which is not satisfied with humidity, it eventually reaches down to a temperature where the satisfying (100%) is reached, and the gas gets wet, giving off condense.
The further the cooling goes, the more water is condensed.

If this condensing gas is warmed up, it starts to dry, and can take up more humidity…

Tom’s Question: Max’s gas cool and condensed / his cool and condensed,

but wet???

In fact both are wet as long as the temperature is declining from the condensation temp downwards!
This condensing continues at the same end temperature as long as
“new hot gas” continuously arrives to the condenser = cooler.

:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

“The extra heat from the added gas will lower the DP more. The net result will be a lower DP.”

Here facts go upside down!

The condensed gas gets an extra dose of high humidity gas, net humidity will increase…but will be condensed as long as the cooler is kept at the same temperature.

If the “extra gas” (hot) is added after the cooler, the net humidity percentage goes up…

::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

Now I hope Tom has a starting-point to put the new questions to Kristijan…

1 Like
#121

I guess we need actual numbers to know if my method will work. I don’t think talking in terms of up and down and then adding a small amount of hot wet gas. The added gas can make the combined gas DP go down from added heat and up from the added moisture .
Thanks for giving the explanation
TomC

#122

Tom, simply sayd. I am sure your method will work but will not be optimal. You will add water from bypassed gas to your engine grade gas, this does not happen on Maxs way. But the question is is this a problem? My guess is no. But like you sayd, lets wayt and see.

#123

Max, l was thinking about what we talked about before, you sayd my 100c paperfilter gas filtration wuldnt work becouse eaven 90% moist gas wuld clogg the paper over time. What about the way you advise? Reheat the cool/condensed but 100% wet gas. The moisture there shuld allso be in the 90% moisture region, once slightly reheated? Shuld this not damage the paper the same way then?

1 Like
#124

Hi, Kristijan!

13.10.2017
It is nothing bad with 100* C gas as such, but what temperature it had as wet, before it is reheated to 100* C !

If hot, relative humid gas from the gasifier is cooled down to 20 – 40* C it will give off a good part of the humidity as condense and will become 100% wet.

Then reheated to 70 – 100* C makes it dry and safe for a nice (commercial) paperfilter. (for a 3 liter motor)

Perhaps a mantel around your cyclone is the first convenient place to get hot at start-up. As far as you blow all gases from the gasifier (after start-up at least) through the cyclone, its mantel will be ready for reheating the cooled gas.

But do not blow start-up gas trough the cooler, it will soon become dirty and loose its efficiency!

Of course the gasifier gas has to be hot filtered before the cooler, if it is not a self-rinsing Imbert type, hardly applicable in you case; then a hot “sootbag” may do the job?

Let me see your proposal!

2 Likes
#125

My original idea does not cool the gas at first at all! Take raw gas from the cyclone, cool to ~100-120c and pass trugh the paper filter. Then, cool, condense, run trugh the engine compartment cyclones to expel the participated moisture and to the engine.
This shuld allso be the fastest startup way, at gas from the cyclone shuld reach 100c faster thain heating the whole gas reheating mantel can be possible. Thods?

First, l will go the easyest, and allso safest way and work from there. I will pass the gas stright from the cyclone to the coolers. Then, cold and driping wer/foggy, send trugh a open cell foam filter, similar to yours on the Audi, where all the soot shuld combine with the fog in form of bigger sooty droplets. Those will now pass two final high velocity cyclones, wich will extract all the sooty droplets. After that, a slight reheat and stright to the engine.
This way is safest too, becouse this way there is no woodgas danger related things in the inclosed trunk, except the hopper.

If this lets too much soot trugh, l will be forced to go your way, building a reheat mantel and filter, in the trunk. Or, try out my original idea, allso, in the trunk.

Can you explain what you ment with the sootbag?

As for rinsing the cooler, it has become a routine to wash the cooler and the car every Sunday when l had the Checvy, so thats a reasonable interval for me as such.

3 Likes
#126

Hi, Kristijan!

13.10.2017
The mantel on the cyclone is “instantly” following the internal temperature!.
After the cyclone, use your famous “soot-bag” filter while hot, and then to the cooler under the vehicle bottom and the twin wet cyclones!

Come back from the wet cyclones mantling around the exhaust pipe, but that is a slower way than using the gasifier’s cyclone mantel! Then to the paper filter.

You have presented the soot-bag filter on the Chevy, one of your applicationes in the alu-box.

3 Likes
#127

Aa that soot bag! I like the name :smile:

Hmm this culd work! I have lots of space around the exhaus manifold.

3 Likes