We are facing some clogging problems in the feeding tubes (14mm inner diameter) of our lab AD reactors (120 L) when working with cow manure due to its composition (high quantity of fibers). We have tried several techniques to avoid these problems but sooner or later they appeared again. We have even chopped manure and passed it through a sieve < 5 mm, but after some time of operation clogging problems due to the accumulation of fibers showed up. What is your experience with such a substrate or similar ones? Did you a find an inexpensive solution which may solve our problems? Any idea will be welcome! Thanks in advance.
I would suggest that you will likely have problems unless you can avoid any suction in your pumping. I have only operated small manure digesters which were manually fed with syringes, avoiding the problem of clogs in the feed and effluent. I have tried pumping cow manure with 1" lines using a peristaltic pump, and still had clogging issues. I think you need positive displacement pumping when you have high solids. Vacuum systems are doomed to fail.
Thank you for your input Zachary. You are right, the main problem is located in the peristaltic pump. Actually, we have seen stratification in the tube that enters the peristaltic pump when it starts the suction. The problems reduce when the pump is put under pressure (below the liquid level of the manure storage tank). Unfortunately, right now we have not the option to buy another pump...
We will try with cow manure from another farm where they do not use straw for the cattle beds... Let´s see how it goes!
Thanks again!
Good thoughts guys! I am going to save this conversation for any future work I do with high solids.
Hallo
We were confronted with similar problems when we aspirated manure from floor surfaces. There we used tubes with inner diameters of around 30 mm - and had still clogging problems. If you do not want to alter the chemical and physical properties, then it seems reasonable to charge the reactor with a screw or spiral.
Best regards
Beat
A) Use swinging sieves with < 1 mm cutoff or less. Depends on the case - and each case is different, as everybody knows by experience !
B) Improve the handling of the manure by allowing separation by gravity at first and pump from the middle level of the tank with less TS.
Best regards
- Badges
- Science topic
- Similar topics
- Biological Science
- Bioecology
- Systems Ecology
- Landscape Ecology
- Connectivity