I think on order to run a shallow charbed you need a more violent air-blast to speed the process up - small nozzles.
It’s a trade-off - char drag or nozzle drag. So far, with my latest build, it seems char drag is not an issue.
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I had a long conversation with JO yesterday, I have been surprised by the gas temperature out of the cyclone all summer, it has been over 300 (573F) degrees c at 50-55mph, now I changed the restriction back to 110mm diameter from 120mm , and got back the low temperature i have befor, it is at 130 (266f) degrees c at 50-55mph. Does ayone understand why?
I’m wondering if the amount of carbon is not enough to reduce when I have 120cm?
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Hi Jan, when you were running your gasifer with the 120cm restriction and with the higher temperatures 300 degrees c at 50-55mph did you have more power or less power for acceleration to get to that speed. If you had less acceleration. Meaning it took longer time to get to that speed then I would say you were over pulling your gasifer. The hot lobe in the firetube was moving down farther into the restiction area. This causes your gases to be burned up. Also it is call the gasifer is going into a heater mode affect.
Why because like you said there is not enough carbon or charcoal bed for the gases to go though to prosses the gases.
What was your vaccum readings like, was it lower or higher on the average at the 50 to 55 mph speed. This is kinda a hard one because of loose or tight charcoal bed affects this.
It sounds like you have found the optimum running size restriction opening for your size gasifer, this is good.
If you could increase the depth of your charcoal below the restriction opening then you could go with the 120 cm opening I would think. As long as you do not make tar or go into the heater affect causing the higher temps.
In my drop box I can run at that higher temperatures and then go right into my cooling rails at about 250 degrees c it cool down fast at this point. Different designs slyclone vs drop box.
Bob
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Thanks Bob, what you say seems right, I think the car is a bit stronger with 110mm, I have thought a lot about what caused the temperature drop, but did not understand. I have thought all summer that I had a leak that caused the heat increase. Do you think I can move the grate down a bit and give it a try?
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Yes Jan you can, this will give you a deeper charcoal bed to draw on.
Between my restriction opening and the grate is 15.2 cm or 6 in. The spacing between the top of the gate and the bottom of the gasifer is 3.175 cm or 1.25 in. I can lower my gate down with no problem if I ever need to.
How much spacing between your grate and the bottom of your gasifer? Some builders are 5.08 cm or 2 in. and more. The grate is just hold the charcoal up and giving it space under the grate for the gases to flow through the grate, the gases also flow out to the sides of the charcoal bed. This is where on a hard pull or vaccum draw you can slip charcoal over the side of the grate. My grate does this all the time. So my next grate is going to be bigger in diameter so there is more suface area to prevent this from happening.
Bob
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What you have said today has made me begin to understand a little of this, I am very grateful.
I probably have at least 4 ", between grate and bottom, so should be able to move it down a bit.
The problem is to get a new mount of grate, have to see how I do, if I should take this to Illern and make a new one for the S10
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Now your gasifer is of the Imbert design? Right. So you can not move your restriction open up closer to the nozzles. In the WK Gasifier design you can do this because it is a lower velocities at the nozzles. This is the beauty of it it can be adjusted at the restriction opening up or down or at the grate up or down. This gives you the proper spacing needed for the restriction opening and the L. or cu. in. size of the engine you are using. You can make the charbed under the restriction opening deeper if need or shallower. The larger fire tube helps with being able to use larger pieces of wood chunks.
Bob
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Strange, I got some good advice from Johan Hedenberg and Gengas Werner, and the car was accelerating as I drove on petrol, it lasted for two days then the car runs as usual.
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Jan, is this a cliffhanger or is it confidential information?
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A cliffhanger, see if I can understand what happened.
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I know Werner and you mentioned the other week you’ve been in contact with Niklas, but who is Johan Hedenberg? Is he the one with an orange Volvo on chips?
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Yes, Volvo and Ford F150, I think it’s called, both drive on chips, and have a test rig and test units on.
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This happens to me too. I am so busy doing things with my gasifer and truck, then all of a sudden it start to perform really great. Then I am stuck tying to think of all the things I did to make it happen. lol It usually happens when doing maintenance clean out stuff.
Bob
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Yes, I think so too, hope you are right, would love to get back the acceleration.
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I have to ask you, the air into the gasifier, do you filter it?
Wood ash is used as a mild abrasive, does it not damage the engine?
I ask because I can not find a filter that both cleans and easily lets air through.
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I do not filter the air going into the gasifer, it will be going through the hot charcoal with ash. The ash and soot will be going through the whole system with the gases until it trys the go through the moist hay filter, there it will be mostly traped. This is why washing the hay filter down with water is good, this will keep it clean as possible, hay works the best for me. I always wet it down after putting new hay in my netting laundry bags so the fine hay dust do not get into the engine intake. If I drive every day I will wash it down once a week and clean my cooling rails out too. I have easy access to them to flush them out down through and into my condensation tank and out the drain and also out the drain of my hay filter barrel. My gasifer always seems to run better with better gas going to the engine with less soot. I have very little soot in my intake to burn out.
Bob
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Ok, have any of you done a compression test before you started running on firewood and after about a year of running on firewood?
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Good morning Jan.
Several years back before I would gasifie a vehicle I would test the compression and record each cyl. After a week I would test again and month then year and so on.
Now it has been several years and I haven’t check but the trucks seem to be normal .
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Good evening Wayne.
Ok, do you remember the result of the test?
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I had a 460 cid ford about 1982- 84 year model if I remember correctly. The compression was just over a 100 pounds .
( 105 - 115 psi ) I thought this was low but after asking some mechanics I was told these motors didn’t have much compression to start with . The compression didn’t change as long as I had the truck.
The V-10 magnum and the 5.2 L 95 year models had 180 psi on each cyl.
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