Hi Dave, Yes, i am going to continue tinkering with this until you guys tell me to scrap it. I will be building a Keith gasifier at the same time. Your new project looks awesome. I see you are using rolled material ------ i am all in on that. The clamp system on barrels seems to be a much easier deal than
flat flanges. What do you think about cutting the lips off the barrels about 2.00 in. down & welding them to the rolled tubes? Well, good luck on your project.
Peter
Matt, You mentioned a condenser. How large & what configuration? Should i remove the tornado or put the condenser downstream & suck through the condenser? I was collecting water in the tornado filter. It has been pointed out to me that my gutter drain needs to be larger.
Peter
Actually I was looking at the pipe plug on the side it looks like there is some tar leaking out there.
But Ive had this issue with it leaking out the lid as well, I use a spring tension device on my lids too. I had to use a stiffer spring and redesign my lid so that the rope seal had more surface area to seal against. Also my condesate troft is built into the lid above the seal so that stuff doesnt migrate to the seal and leak out. Have to be carefull tar doesnt glue your lid shut too. Try tightening the springs but just enough so it can still function as a flash back arestor. Once I had the lid sealed I had almost zero tar in my condesate troft just a little water.
Are you experiencing presure build up in the hopper? If you are generating presure inside Im not sure what may be causing that. There shouldnt be that much presure inside the hopper if any at all, at least in my experience. Ive had some flash backs at light up periodically but thats about it.
Keep at it. If thats your first unit it really is a nice first build. It makes my first one look pretty silly. lol
Alls I can say is be creative with your condensor. There are so many designs out there. I use 1 1/4 tubing for my cooling tubes and have 8 of em in an array at 18" in length that lead to a resivior at the bottom. Then I have a return tube exiting to the top and out.
Your max CFM and how hot your fuel runs in your system determins how much you need to cool your gas. The cooler you can make it the better. There is a lot of condensate in the gas along with the tars. Im actually concidering redesigning the condensor on my large unit and making it bigger. I will also be building a large fan cooled unit in the next few weeks for testing. So far my machines are for small engines, but I will be experimenting with moding my car soon.
You can not filter the tars if they are in a gas form like the steam. It needs to be condensed first.
Leave your cyclone on it. If it works as good as it looks it will get rid of ash and large debris
Mat, All the leakage you see is from the cover seal. The springs are nitro hemi valve springs. I can put as much pressure as i want to seal the lid with out the chance of even coming close to coil bind. The question is, how much tension is too much for a flashback? I had no idea, so i ran them loose. part of being a beginner i guess. Maybe what i thought was pressure was just the steam escaping under the gasket. If the lid was not sealed properly, would this cause excessive condensation?
Peter
With out seeing it its hard to say with the spring presure. The valve springs may be too much though I dont know. I went from some whimpy spring from Home Depot to some heavier springs from a tool supply company. They arent even a 1/8 thick and I use just one for the whole lid. I crank them down about an inch so there is presure on the lid and then grab the handle and pull up on the lid. This is just my guestimate but in my situation I think there is about 10 lbs to 15 lbs presure on the lid. How much is too much that is a good question. I dont want to find out, but may be some one here can chime in on this one.
Matt, Maybe i will switch to a thicker more pliable gasket in order to seal with less pressure. Do you use rope or flat style gaskets? When these flash back, is there a large flame out from under the cover?
Thanks for the input.
Peter
I use the rope,
Most flash backs Ive seen it just looked like the unit had to burp. No flames are any thing like that. One time it did it was during a shut down and the fuel was way low and some small ambers shot out. But the rest of the time this would happen during a start up, nothing real major. Never look directly inside the ignition port either if a flash back occures its coming at ya.
Oh and if you light your unit outside on a nice sunny day never look down inside the stack to see if its lit. You might burn your eye brows off. Not that I would know from experience. lol
Actually that made the sale, I did this in front of a customer. The flame was so clean we could not see it at all.
Good looking unit; you should be able to tweak it. Getting the lid to seal and taking care of any other leaks will help. Posting up you reactor dimensions will help in determining if there are any other problems.
Keep at it!
Hi Wayne, Thanks for the response. I will be posting some detailed pictures shortly with dimensions. Hopefully you guys can help me out. Again, thanks
for the encouragement.
Peter
Hi guys,
I took the gasifier apart so you guys could have a look. All of the leakage on the outside of the tank is from the top cover. Pulled the reduction bell & screen down, dumping everything to the bottom. I really do not know what I am looking for. From tip of nozzle to nozzle is 10.00. Fire tube diameter @ nozzle ht. is 13.50. At the first step out over the nozzles, the fire tube is 15.00. The rest of the tube is 20.00. Top of bell is 2.50. The bottom is 9.00. The screen is 11.00 dia. Nozzle ht.is 2.00 from top of bell — 4.00 to floor. The screen hangs 1.250 below the bell ( sides of screen .250 over bell.) 10 nozzles with .290 openings. The hearth is made out of a 16in. budd wheel, jacketed for the nozzle air & fed by a 1.500 tube, not preheated. Does this design have any inherent flaws? After looking at Wayne’s units, the reduction bell system that I chose to build may be a problem. This is easily changed as it bolts in on an 8 on 8.00 pattern. The outer tank is 23.50. Well, I guess I just need to know if this unit is worth continuing on.
Peter
Hi Peter, I’m an, I feel, an advanced beginner, having a FEMA, fluidyne and GEK type design built and fired. Each was a bit more advanced and all were great learning experiences. My, and all FEMAs, don’t develop high enough temps to crack tars and H20(steam) so they flow out with the gas stream. Steam pressure doesn’t build up in the system like a boiler. If you had the right size cooler in line, the H20 would condense out into an airtight catch basin of sorts. The tars come out liquid with the rest of the H20 in the flare tube. A filter in line would remove a lot of the tar before it enters the engine. Alas the FEMA is a tar maker but a good learning exp. Check out my FEMA burn http://flic.kr/p/9B28Nm and see the tar and moisture sizzle out of the flare tube.
I moved on to the fluidyne and got mixed results because I only tack welded the fire tube to the flange and some gases by passed the reduction zone heat and were uncracked and condensed out down stream. All this info to get to this, air leaks lower hearth temp. I always tell folks to leak test all welds, fittings with really soapy water ( add a couple drops of glycerin for stronger bubbles) pressurizing the system cool and see where you get bubbles. Fixing the leaks is step one. Don’t dump what you have now, I think it will work. I’m looking at the numbers you are working with now to see how they line up with imbert specs and offer an opinion.
Pepe
Hi Pepe, Thanks for the help. Do i need coolers to merely flare the unit? Right now i have not even been able to do this. Too much water!!
The flare tube is constantly dripping water. Any suggestions are greatly appreciated.
Peter
After start up in an imbert style like yours no water should be in the gas stream after it exits the char bed on the grate. Your hearth is not getting up to temp, IMO. Your restriction is too small and you need to increase the distance from top of hearth to nozzles and you need to keep the fines cleared from the grate… I’d tackle the leaks first and the few physical changes you have room to do.
The cooler can remove water but there’s not supposed to be any at this point in the gas stream. The cooler cools the gas making it denser (more BTU per ft3), gas should be 80 to 100 degrees on entering an ICE.
The Imbert nozzle and hearth diam chart lines H and I have a hearth diam of 10.25", yours is close at 10".
Your firetube diam is 13.5, right between 11.75 and 15.75 on the chart. H plus R ranges from 15.3" to 20.5", yours should
fall in there somewhere (this is vert “A” dimension).This is where your flaming bed of char on the grate will rest as the
gas is pulled through it and the magic occurs.
I agree you need a bigger restriction, around 5" and the distance from the C/L of nozzles to top of restriction should be
about 4.75". You’ll need a grate that you can easily shake the used char through on a regular basis during the run or it
will clog up, slow gas production and/or stop it. I’m not sure if you have room to fit this in under the grate but clearing
the fines is very important for uninterupted gas production. The grate should be wall to wall if possible.
It’s a lot of work to scrap so implement what you can and see where it goes. The imbert charts are in the resource section here.
Hope I didn’t confuse the issue
How much char did you have above the jets?
Pepe, Thanks for doing the homework. If i make a flush to hearth bottom, reduction tube, this will give me 4.00in of char under the nozzles. Is the reduction tube supposed to be full of char all the way to the grate? I do not understand “wall to wall”. If i used a 5.00 tube, this would give me 3.00 of
overlap with my 11.00 grate. The grate is on chains with a rod that enables me to shake it from the outside. Is this what you were referring to?
Thanks Peter
Hi Matt, Sorry i did not answer sooner—could not find your message. I had approximately 2.00in of char over the nozzles. Is the reduction tube supposed to be full of char all the way down to the grate?
Peter
Thats probably about right considering the size of your machine. It looks a lot smaller than it is. Yes you want char all the way from the grate all the way to about 4" above the nozzles. You just dont want it packed in there. I see a lot of white in your char indicating too much air = ( too much cumbustion) or too loose of fuel for your set up. Even with the high temps the water still may be a result from the short char bed from your restrictor to your jets.
Edit: not to confuse you with the temp thing. It has to be in the right place.
You may have too many jets for the size of your hearth. But I have seen some simalar units that work. So for now Id do all the stuff that is suggested above and on the other thread first. Then we can play with the jetting.
Hi Matt, All you guys have been great in answering all of my stupid questions. I have learned a lot in the past few days. The mistakes that i have made are being corrected, some too stupid to admit to!! This is the first time in a long time that i am the beginner at an ICE project of any kind!! Actually, i like the challenge & am enjoying being the beginner for now — good change of pace. Once again, thanks to everyone for their extreme patience.
Peter C
