I am thoroughly convinced that my lid is not leaking a substantial amount. When putting the lid down, I run my fingers around the edge to make sure that it is centered before I lock it down. I have unlocked the lid and tried to open it with the vacuum blower pulling on it, and I can not break the seal. If you are really serious, that you think all of my problems are related to a leaky lid, I could run a smoke test. I could put the top and hopper fill lid back on, throw a smoke bomb into the hopper and turn the kirby on to push air into the silo.
For years i have understood that the solution to many problems can be found by doing a systematic removal of everything in the hopper down to the grate in the burn tube, and then go to the ash pit and look for unusual signs. In conclusion of this tare down, I am not getting radiant heat up into the “wood” to create char and without char, the remainder of the system will not work. The wood blocks I took out were smokey colored, but not charred, even down to the area of the nozzle plane. I found no signs of white ash indicating air leaks.
My frustrations right now are overwhelming. My first build that worked was built out of “stuff” I had laying around my shop. It was all done to the dimensions that I found in one of the tables in FAO72. I did change nozzle orfice diameters a few times but stayed with the other dimensions specified. Many other modifications along the way but all above the fire tube and/or outside of the gasifier.
This build I kept the basic dimensions-- nozzle tip diameter, nozzle height above the restriction, the restriction diameter. The changes were 5 to10 nozzles and the book only went up to 7; the reduction was totally changed. The original design had a reduction zone that was dictated by the diameter and hight of the brake drum and the only insulation was from the mass of the brake disk that was attached to the bottom of the brake drum… The height and width of the new reduction zone was based on a theory that you draw circle that will touch the tips of the nozzles and the bottom will fit within the restriction. Then you make a reduction zone that can contain a a circle 1/3 the volume of the circle above the restriction. The reduction circle should fit within the bottom of the restriction. The reduction zone wall were backed by a hollow behind them that was filled with char/ash to insulate the zone instead of the mass of the added brake disk ring.
I am totally embarrassed by this project. I have been in this program long before many of the others who are driving on wood. The ones that followed Mr. Wayne’s instructions pretty much to the letter I understand their success. But we have several others who have built multiple vehicles and gasifier types all with success.
I feel now that if I ever want to get back into gasification, I should go back to the “junk” I originally used and reproduce that system. I should forget about all of the modifications that have been suggested and let others build them into their gasifiers and prove them before I get so crazy with them.TomC
Hi, Tom!
1.10.2018
Welcome Back!
You are now describing manual closing of the silo lid!
My question has been, and still is:
If an internal pressure “blows” up the lid to say 10*(degrees),
How well does it seat again (on the road)? Diversity times?
Is the hindge(arm) broad enough and sideways stable?
This regular function must go flawless every time, without manual assistance!
Does it fling up and flap down consistent without malsettling, and missing the seal?
The consequence I described on last message 921.
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I understand the pain in trying out system after system and getting none of them giving satisfactory results!
Detailed descriptions and skizzes, pictures makes it easier to
comprehend things RIGHT with a minimum of errors.
Of what I have seen in this version so far, only the bottom part
remains a bit vague. And the lid mechanism.
Pleace, deliver your observations!
Tom, it sounds like you’re frustrated. I get that. I hope you just give it a little break, take a deep breath and try again.
Max,Max,Max; I feel we are flogging a dead horse. I am not sure how many of the others are interested in what we are doing/saying. On the other hand, we seem to be the only ones talking about gasifiers.
Just a few abstract comments:
- I believe my hopper lid has an adequate seal for the reason I previously stated; Observation-- At shut down I do get smoke out the air intake manifold port, and a small amout seeps at the hopper lid.
- Under operation the hopper runs at a vacuum of 2 to 6+ inches water vacuum. This vacuum tends to seal the lid tighter.
3 I will do a pressure test if you really think this is a problem but I don’t think a pressure test will prove anything. If the hopper has a small leak at atmospheric conditions, the pressure will push the lid up and make it appear to be a larger leak that it really is during operation. - No, if I open the hopper lid and drop it closed, it will not fall centered on the ring it fits against. As I said when I close the lid, I run my fingers around the under side of the lid to make sure it is center on the ring before I latch the hold down. You mentioned the lid opening to possibly 10 degrees durning a hopper back fire. With my lid, in such a situation the lid opens possibly less than 1/32nd of an inch. ( sorry mm ?) It does not “explode”. It makes a sound more like a fat man passing a rather large amount of bass.
- I interpret what you are saying is an air leak in the lid will add to the flame front from the nozzles and make them more lazy, allowing them to bend toward the restriction, and as they go through the restriction the speed increases and the lazy flame becomes more active as it hits the hot char/ash on the grate and creates clinkers.( this is as close as I can explain what I have gotten from our discussion.)
- Now if I am to do a pressure test, I will try to tell you what I plan to do and then you can make any comments or suggestion, before I do it.
The basic procedure I am proposing is to re-install the top lid on the hopper and that will include the hopper fill lid. I have no intention of standing on my head and re-install the nozzles. The drop in restriction and reduction bell will not have the ash around the edges to seal them as they would if I was trying to run the gasifier. I will put a piece of screen over the restriction to act as a temporary grate. I will put some damp wood chips on the screen and light the chips until I get a good smolder smoke coming off. I will close the hopper lid as I usually do, and start the kirby blowing air into the ash pit ( hopper). I might be able to take the vacuum gage out of the hopper and hook up a regular water manometer to that port. Now how much pressure do you want me to use and I guess I will have to take pictures of the hopper lid at various pressures. Would you accept me putting tape across the air intake manifold so that I don’t have to run the kirby at such high velocity? Any suggestions?? TomC
I read and enjoy every word. Keep 'em coming!
Don Thank you. I would hope that from time to time if you see something in these post that you could add to, you would jump in. You are one of the relatively new fellows ( in perspective to my time here) and you have done so much that I really would respect anything you would say.TomC
Hi, Tom
1.10.2018
- Here is the main point: Self seating! After a boom!
On the road it has to restore normal operation conditions wihout ANY human intervention!
“Sateliting” or otherwise!
The lid has to be hinged with an arm, sturdy in all directions, allowing only up and down movement determined by the hinged arm geometry! Feather powered and locked.
The arm has to be joined to the lid-center, and no other places! (on the lid)
It has to handle itself under all circumstances!
Establishing this is the only way to travel in a normal way…
Tom,
What Don said. We’re all listening and learning.
I do get what Max is saying about a leaky lid but as long as you have a hopper vacuum you consider normal you could probanly consider the lid pretty tight and the nozzles blasting good. I don’t know about your hopper but mine gives me warnings by sneezing every other mile if it leaks too much.
You mentioned what kind of hopper vacuum you usually see, but what about vacuum downstream the grate? In other words - what’s your vacuum ratio / state of the charbed?
I’m of course aiming at your fuel size again. Also with sawed chunks there’s a lot less surface area compared to your previous fractured chunks. I strongly belive you would get a lot lower grate temp, no ash melting and more power, with a richer diet.
Hi, J-O!
1.10-2018
Be sharp! Here is just revealed a Great difference between careful “handseating” and “blurp” pops on the road!
The guiding is A and O!
And Yet nothing told about a guiding arm or not!
Not eaven a picture…hoping…
A real feather-bow is probably too much of a dream…
Ditto what others have said about enjoying the posts. Yes, I do, too. Regarding the tar and charcoal dust, and the “mess”, I also get quite a bit of complaining from the 72 year old wife who is the chief cleaner, picker-upper, and pot and kettle washer. The trade-off (for her) is that I use my charcoal-making TLUD stoves to do the majority of the cooking/frying/boiling/water heating in our outdoor kitchen, and she gets very good compost enriched with charcoal fines for her gardening and house plants. Now she complains that the cast iron pans/pots/woks are too heavy for her to move in the sink and drying racks. My suggestion of just wiping them out with an oiled rag was dis-regarded. Plus, I’ve been hearing words that perhaps I have “enough” engine grade charcoal, and should actually buy some new jeans and shirts to replace the ones I have ruined with my dirty hobby. Plus that, I sometimes get reminded to shave. (Hey, that is just charcoal dust!) What are these old women going to do with old men with dirty hobbies?
Oh well…
Thank you JO for jumping in. You are one of those people that I really respect and have had a very fast learning curve since you got into woodgas.
I only have two vacuum gages. One is in the hopper and the other is in the cooling pipe that crosses from one side of the bed to the other. I have to go back and make a “general” statement because it has been so long since I have actually been able to drive. Generally my two vacuum gauges vary by 50%. Cooling rail 10 in. h20 and hopper 4-5 inches.
I have to ask what you mean buy “richer diet”. I’m thinking you mean smaller chunks that will pack a little tighter. I have several buckets of oak 2x2 stickers that have been sawed into cubes and diamond shapes. I do not like the looks of these and I haven’t tried running any of them. I can’t fracture them without my chunker, but I think if I saw them 2x2-1, even the sawed ones would work better.
My wife asked me if I was going to the shop today ( haven’t been there in about a week) I told her no and told her why. She suggested we run to town and get some coveralls. I have been looking, but haven’t found any and she call a couple of places with no luck. ( amazing that they don’t have them anymore) With cold weather some stores have lined coveralls that are not as heavy as the ones I use in full bore winter. Otherwise I may go to Mr. Wayne’s coveralls and an old jacket.l TomC
Ray; You seem to have a good understanding of what I am going through. My wife is one in a hundred and unless she is happy, I am not happy, so I want to do anything I can to keep her smiling. There was a time when I would NEVER ask her to help me, but with my health now, she has taken over most of the chores around here, and I am stuck with riding our lawn mower around the property about 1 day out of 5. Kind of a useless feeling. TomC
Hi Max;
The only time my gasifier- burps- is when I am first starting it, and a some point I open the lid to see how things are going and maybe stoke the fire. When I close the lid, I let air into the hopper, that after a minute or so it will burp. As I tried to explain before the lid does not “blow” out a burp, it just “flutters” the lid up and down about 1/32 inch. or less.
I don’t understand “The guiding is A and O!”
Picture to come.
“A real feather-bow is probably to much of a dream”. (???) TomC
Hi, Tom!
2.10.2018
You have just a while ago described that you have to "hand-
adjust" the lid to get it tight! (Your statement.)
Now, every bang or burp or flattering SHIFTS the position of the lid so much
that it does not keep tight!
That is my point, not the count of burps of whatever kind!
Therefore I have asked what kind of guiding you have applied to handle this problem!
You have avoided to answer to this question in “ten different ways”.
A feather bow is a flat steel bar (used in packages as car suspensions).
They are rigid enough to keep a lid in position, if the hinges are well and tight done.
They do not allow any wrigling sideways.
I hope you are getting suitable overalls for the winter and workshop!
Aha, your photos have arrived. In principal quite OK!
Hope the lid can settle automatically after a good service!
Hello Max;
I did say that.
That is NoT what I said. After I get the lid centered and locked down on the free end of the feather bow, the lid is locked in the center position and with the “fluttery” burp it does not move off center only up and down a miniscul amount. TomC
Hi, Tom!
2.10. 2018
Hi, Tom!
Sorry for my misquote!
I think I had memorzed it from an earlier occasion.
(I have corrected the source in my original.)
Hello Mr. Tom.
My uncle told me when I was just a kid. ( If I wasn’t wearing my overalls I was just as well wearing a dress ) 
Mr. Wayne; My father always wore bib overhauls. He was a machinist, and it was so handy to put his micrometer and 6" scale in his chest pockets alone with pencils etc, etc.TomC
Actually Mr Wayne’s expression. Has to do with the amount of active surface area. Fractured chunks that look like small air breather filters will provide a richer diet to the gasifier vs flat sawed chunks.
They say the Swedish coastline is 4 laps around the world long. I often wondered how far up every creek they pulled the tape 