Looking at the soot stuck to your filter, does it fall off easy when touching it from the inside of the welding blanket or is this soot baked on and hard.
Thinking out loud here. If your frame was built so the welding blanket would fold in between the frame piping length ways. With the bottom of the welding blanket tied together and a stainless steel bowl inside at the bottow hanging with weight in the bowl. As soon as you would let off the gas petal. The weighted bowl would go down and strighten the welding blanket on the vertical poles frame. The walls would flex in and out causing the soot cake to fall off. This has not been test except in my thinking in my mind. You would need about 10 lbs. Or more weight in the bowl. The bottom of the frame would need to be very smooth so it would not wear through the welding blanket or better to have it reinforced.
I vison a mixing beater not 4 but 8 smooth blades and the welding blanket over it.
This winter the road has been very bad, they havenât plowed until the cars have driven down the snow, so potholes all the way.
The plate that the rebar is welded to seals against the barrel, has an edge welded to the wall of the barrel that it seals against, you can see it in this picture.
Jan, does this pressure drop effect the performance of your vehicle?
I ask because to me this seems like its doing what it shuld. Once enaugh soot cakes on it will start falling off in big chunks, exposing the fresh cloth below.
If you realy feal the need to help this proces, usualy sack filters have blowers inside. A burst of pressured air will inflate the sack and throw the cake off. You can do this occasionaly with a strong shpovac o similar
The soot falls off quite easily if I touch the blanket.
I had exactly the same thought as you about the weight, talked to Johan about this, (he with the Ford and the Volvo) but he thinks quite a lot of weight is needed for this to work, but maybe if I put the posts in a different way in the inner frame .
It pulls the inside and outside of the cloth together quite easily, and then it becomes tight at once.
Yes, it takes the effect down. not so much though, but I have cleaned quite often, so that it doesnât shrink the barrel or leak past.
I made one like this and tested it a few days ago, but it didnât work, only had 2kg of pressure in it though.
How many m2 is your filter?
However, the purification works well, now the water from the rear tank is completely clear.
It takes about 10-20 minutes to lift the filter and clean it, but I must be doing something wrong because the SMP could drive 2500km without cleaning, sometimes up to 4500km.
Itâs 2m, should have at least 4m, but think the cake should fall off anyway?
Yes, probably even more. The thing is with sack filters, sacks do not do the filtering. The cake does. So you need a vast surface area to breath well. Then, thick cake can form and fall of, without much pressure drop.
Hi Jan. I was thinking that perhaps if you have a frame inside in the top you could have a small weight hanging like you had in your hopper to prevent bridging.
It only needs to vibrate the frame a little or push the cloth a little to help a cake fall off but that too needs to be very smooth as Bob said.
Just a thought.
Yes, if you hung a weight inside it would maybe work on the inner canvas, but there is only about 3cm between the outer and inner canvas, so I canât get there.
Hanging in the frame I think it would just break at the top.
Iâm also a bit worried about tearing the canvas.
Hi Jan, i think 2m2 is on the smaller side, itâs a matter of pressure drop/surface cm2, the pressure drop through the canvas is what pushes the soot-cake to the canvas, and slightly in to it.
If i remember correctly Max Gasmans formula gave smallest area for a Chevrolet 350 (5,7liters) 7-7,5m2, to give a self cleaning filter.
Svedlunds old filter for wood was 3m2 for engines 2-3liters (slow running) these needed daily cleaning.
Yes, I guess 4m would be much better, I have looked in SMP 1951-1962 they have 2.33m to 3.6 liters and 4.66m to 6.23 liters.
How do you prevent the filter cloth from being pulled together, then the surface should disappear quite quickly?
Do you have any advice on execution, with welding cloth?
Is this how you did with a mesh on your old filter?
Did you have a whole mesh or small pieces for each pocket?
Hi Jan, i try snap some picâs when home from work.
I used net like this, folded it exactly like you show with wire.
This net rusted for me and damaged the canvas, but it held up a long time anyway, i bought it as stainless, but it wasnât.
Probably the net rusted when the truck wasnât in use under a winter period, (like exhaust pipe do)
Thanks Göran, just ordered more fiberglass fabric.
Saw that they had 0.9 meter x10 meter steel mesh on jem o fix, should suit me.
I donât know if these picâs will help some, Jan,
Iâve moved the old filter with my crane once, and also backed in to it once, and ofcourse the rust had done the rest.
From the top. There also was a center pipe that the net was wired on, but i re-used that.
It has lost Itâs âstanding star shapeâ
The folded net, even if the fabric was âsucked togetherâ there was always some passages between wires.
A piece of glass-fibre welding blanket, this is maybe 2/3 of total lenght, and missing 30cm top and bottom.
At the top i used this stainless wire clamps to help the blanket stay in place.
The net cage was net folded in a zig-zag pattern, and the rolled to form a cylinder, ends wired together, then center pipe inserted in the middle (center pipe had a lot of holes drilled)
I think that thing in the first picture tried to eat New York in a movie I once saw.
Are you thinking of âThe Blobâ?
Thanks Göran for the pictures, I think it looks like it will be very tight between the pockets, I donât understand how the soot can fall down.
What kind of thread did you use when you sewed the filter together?