High g-force factor
In the production the processing agents often prohibit their final dewatering by a thermical drying. Some other compounds are thermolabile; others change their colour by heat supply. Therefore an efficient drying requires the highest possible g-force factors. In most cases pourable and compact cakes are formed by the extensive extraction of moisture, so that during discharging the shear forces of the peeling knives do not generate a thixotropic resp. dilatant behaviour of the cake.
So increased centrifugal forces are the basic requirement for an effective dewatering of also fine-particulated filter cakes and so again the basic requirement for a trouble-free, closed operation in the production of active pharmaceutical ingredients.
It is notable, that in spite of comparable basket diameter resp. rotor diameter of all competitive systems the Krettek-products strongly stand out from the inverting filter centrifuges. So the filter area of the inverting filter centrifuge with an exemplary basket diameter of 600 mm is relatively low with 0,45 m², the filter area of the Krettek-centrifuges (Ø 630 mm) amounts to nearly 100 % (0,89 m²). Something like that is to be noticed at the consideration of the g-force factor. The nominal volumes vary more. But it should be noted, that the indicated nominal volumes of the inverting filter centrifuges are related to a cake height of 155 resp. 200 mm. On the other hand the Krettek-centrifuges have procedural a very clear advantage with a relative low cake height of 77,5 mm. The negative influences (filter cake resistance etc.) should not be described any more, because they are normally well-known. So higher cake heights automatically result in longer centrifugal times and also to a significant increase of the filling time.
From this point of view and under consideration of all influencing factors of a complete batch incl. accelerating, filling, dry spinning, discharging, braking or the intermediate step washing, astonishingly significant advantages are arising for the Krettek centrifuges. From such a, not unrealistic point of view the batch times of the inverting filter centrifuges are normally the 4-10 fold of the Krettek horizontal peeler centrifuges. Also here the Krettek horizontal peeler centrifuges outperform the suppliers of inverting filter centrifuges by lengths. The considerable differences lead to an enormous customer benefit for the centrifuge operator when using the Krettek technology, which is reflected in the highest space/time yield. In other words: process technology high-performance machines in an extremely compact design.