Problem of mother liquor removal in horizontal siphonic scraper discharge centrifuges
Thread Content
“The mother liquor outlet is located on the side of the centrifuge tank; it has a diameter of DN200. The large amount of liquid resulting from the separation process is discharged through siphons and skimming pipes, while only a small amount of liquid is discharged through the mother liquor outlet. This is an exact quote from the manual of the horizontal siphonic scraper discharge centrifuge: the liquid skimming pipe should be located inside the drum, while the separated liquid is outside the drum. So, how does the separated liquid exit through the liquid skimming pipe? I still don’t understand how it works exactly. I’ve heard that it’s used to remove the “oil layer” from the filtrate; could someone with more knowledge please explain it?
Skimming is carried out using skimming pipes inside the drum, taking advantage of the static pressure of the liquid (under the effect of centrifugal force)
Both the liquid skimmer and the siphon utilize the inertial pressure generated by the high-speed rotation of the machine. When a siphon centrifuge is used for the separation of corn starch, after a single batch of feed is processed, an oily yellow slurry forms on the surface, creating tension that affects the dehydration process during the next batch of feed. Skimming liquid is used specifically to remove the yellow sludge from the surface. Also, when the feed concentration is low, after the feeding is complete, the solid phase settles at the bottom of the drum; skimming can then be used to remove the liquid from the surface, thereby saving time on separation and dewatering.
The centrifuge must be equipped with a mother liquor buffer tank, right? How is the size of this tank calculated?