A good mill setting should indicate among other things the presence of juice not only extracted by the delivery opening, but but also by the feed opening. But more or less the amount of juice extracted by the feed opening also indicates the presence of slip occurred in a unit of mill. Heavy slip is definitely occurring when too much amount of juice extracted by the feed opening. And that means the forefront of the feed opening; the space before and between the top and and feed rollers is full with liquid (juice) that makes it slippery. Such unwanted slip would not occurring if the ratio is determined correctly for the feed and delivery openings. Remember the term of ‘feed roller’; the function of the roller is to feed the delivery work opening to do a good course of extraction. To be able to reach the condition the determination of the ratio between the feed and the delivery works opening is essential, and remember that this is also concerning the optimal crushing capacity to be achieved. To analyze the amount of extracted juice at the feed work opening, let’s back and have a look to equation (11): V bf r f = ---- Vef Because r f f as stipulated in Chapter VI has a constant approximate value of:
then
:
r f
≅
1.1
V bf
≅
1.1 Vef
The volume of juice extracted by the delivery opening is:
While
:
Hence
:
Vejd V b
Vejd and because: Vef
then
:
Vejd
or
:
Vejd
= V bf – V b ----à (no-void volumes) = r.Ved ≅
1.1 Vef - r.Ved
= i.Ved ---- à i = ratio of feed and delivery work openings ≅ 1.1 i.V ed - r.Ved ≅
.................……………………………................. ..... (19) (1.1 i - r) Ved .................……………………………............
Let the volume ratio between the extracted juice of feed and delivery opening is = y. It means: Vejf ----- ---- - = y Vejd or
