Evaluation of constructive solutions
For the centrifugal solid-liquid separation in the food and pharmaceutical industry inverting filter centrifuges as well as horizontal peeler centrifuges have been established worldwide. While during the eighties up to mid of the nineties of the last millennium for pharmaceutical applications the turn upside down of the filter cloth had been considered as the non plus ultra as a very important selection criterion, a discernible trend to horizontal peeler centrifuges in pharmaceutically suitable design can be noticed just in the last years. Increased cake level for the purpose of identically throughput at inverting filter centrifuges with the effect of strongly increased cake resistance and hereby extended dehumidification time – shown on the example of Krettek horizontal peeler centrifuge PharmaCent® PhS and inverting filter centrifuge at comparable diameter.
The reason for this is that the manufacturers of horizontal peeler centrifuges on the one hand have optimized the filling and discharging systems and on the other hand additionally have eliminated the alleged deficit by the use of a double-side working blowing-off device for the removal of the heel cake. This pneumatically solids discharge will be simplified by the reduced residual moistures of the filter cakes, which will be realized system-related by the higher g-force factors of the Krettek horizontal peeler centrifuge.
Furthermore a modern pharmaceutical suitable design of horizontal peeler centrifuges enables an almost 100 % visual inspection of the process housing. This is not possible with inverting filter centrifuges. An additional negative influence has the necessity of a variety of screw connections. The same applies for the service, because the high quantity of necessary components for inverting filter centrifuges complicates and increases the price for rotational-stressed aggregates.
All in all the basic requirement for an economical centrifugation is the compliance with the physical laws, i.e. possible high g-force factor at possible high filter area considering the hygiene standards to be used in the design. As a consequence the use of the Krettek-technology results for the centrifuge operator in an enormous customer’s benefit which will be reflected in highest space and time yield. In other words: processing high efficiency machines in extreme compact design considering the continuously increasing hygiene standards.