I seem to have a major clogging problem between celullose(lead) and resin(lag)towers. I use a 33 gallon drum filled to top with Arborpure(sawdust/shavings). At the bottom I have installed a 12in diameter 80 mesh screen raised up 1in from bottom. The fluid exists thru a weld on fitting at bottom then thru 30 mic cimtek screw on filter. The fuel is then fed up thru an 8in Thermax filled tower. At the bottom and top of the tower is a 5in diameter 80 mesh screen. Bio is demethed and settled then pumped via small mag drive pump at 15gph. Worked great for 300 gallons(50gal batches)then no flow. Each drywash tower has a drain and could not get fuel to drain from either one. Applied air pressure(20ps1) and barely managed a trickle. Is the sawdust getting pass the 30mic filter then swelling at 80mesh filter at the bottom of lag tower? I have used resin drywashing for a couple of years with no flow problems and now with the use of woodshavings I'm at a lost. Any feedback would be greatly appreciated!
The wood shavings could be plugging the filter. I use a 10 micron filter on my BD Zorb tower and have plugged it once so far. Have not had any plugging problems with my resin tower. Have you looked at the shavings? They could also be breaking down to a paste that would also plug. I upflow both towers to help prevent wood shaving compaction. I would take off filter, disconect resin tower and try and pump. If plugged start by changing the shavings and clear line. Hook up resin tower and pump. If there is a little flow put not normal wash with methanol. If plugged take out and wash or replace. I would also recomend a 2 micron biotek hydroglass particulate-water filter at the end of your Thermax tower. Let us know what u find out. Your 80 micron screens could be plugged also.
Thanks for the feed back. I emptied out the lead(cellulose) tower and it seems that having the the sawdust in direct contact with the screen was the culprit there. I am going to put a raised barrier in the bottom to solve that problem. The clogging in the upflow resin tower is still a mystery so I will have to empty that as well and maybe go with down flow. After the lead tower the fuel is at 80ppm and only 300 gallons have been run thru so I have a hard time believing soaps are to blame. I do have a 2micron filter at the outlet of the lag tower. I think you may be right about the sawdust forming a paste and coating the screen. Thanks again for your help. This forum has been invaluable to me over the years and your help is greatly appreciated.
If your at 80 ppm soap with a 30 gallon drum of wood shavings and an 8 inch diameter thermax tower with only 300 gallons, Im thinking you are not getting good resistance time with the wood, or you have very high soap levels before drywashing. With just the barrel of wood you should be close to the astm range. Test the fuel after the barrel and see what its at. If its over 500 ppm you are going to load up the thermax prematurely. To get the number of gallons from resin or thermax Macro beads the manufactures say they recommend under 500 ppm soap from what ive seen. Your set up should handle 15 gph perfectly with wood chips and a themax tower with soap levels near zero for hundreds of gallons then slowly rise. If you have soap levels in the 2000 to 5000 range, ( ive made fuel very high like that) the wood will be loaded fast also. I change mine when it hits 700-1000 ppm soap. wood is cheap.
With your Thermax tower. I had a customer with a plug issue once. We discovered that there was a 2 inch soap layer and a soap covered screen. Hope you get it all working again.
Thanks again. Before dry wash soaps range 1300-1600ppm.I do whole batch demeth then settle. The 80ppm is after lead(cellulose) but before Thermax. After Thermax no measurable amount of soap is seen. I use the soap kit from Utah Biodiesel. My point was that with only 300 gallons @ 80ppm soap going thru the Thermax, build up of soaps should not be the problem. My setup is based on Greg from Arbor's recommendation and his thoughts are consistant with yours so I'm afraid that I will just have the empty the Thermax tower and find the problem. I'll let you know what I find. Thanks for taking the time to help me with this dilemna.
I also do the WBD, bubble off the last bit of meth and settle for 5-7 days. Soap ppm after 5 days is around 300-500 ppm.
Your asking alot of the sawdust when you send the bio thru with a high soap count. Settleing is cheap and easy.
I run the bio thru my sawdust drum 2 times and then do a soap test. As soon as i add 12ml of bio to the blue solution it turns yellow-green, no HCL needed!
Thanks Mauser. My systems need to produce astm fuel in a 24 hr period so I don't have the luxury of time. Unfortunetly as you pointed out this kind of speed exhausts drywash material prematurely. I am able to accomplish my goal but I need to make sure the initial hydraulic dynamics continue without problems.
I filled my 55 gallon in 2 layers. I gravity feed my barrel from top. So 1st layer is sawdust and the second layer is woodchips and i have on the top and bottom a 200 micron mesh. After that it goes trough 20 micron & 1 micron filter. After all that I polish it trough a drywash tower with purolite pd 206. I do not expirience any clogging.
You may want to check the distribution system in the resin tower as some media may have clogged the distributor.My system uses 100 mesh top and bottom and i always upflow with the wood media i get from Heartland. I have never clogged a tower yet.My buddy had a lot of issues with another system and he was downflowing as well.