Filtration of seed oils
The first fully automatic machines for the winterization of rectified olive seed oils (capacity 600 m2) were constructed in 1984. In 19085, the first automatic membrane filter was built along with the implementation of the technology necessary for the production of a system that laid the foundations for the modern filtration of palm oil. At present the company can produce from 80 to 140 machines/year, of which 55-60% are sold in all countries of the world. “Today we can manufacture machines like Wintersei – explains Donzella, – a very special filter-press that remains closed, with no need of inspections and openings, for a period of time which corresponds to the service life of the filtering cloths.
Diatomaceous earth, cellulosebased filtering supports or other implements are not necessary for its operation, and neither is there a need for solvents, because the machine separates the stearic parts and waxes from refined oils by means of non-metallic filter cloths and plates equipped with an internal heat exchanger. The possibility of maintaining a controlled temperature during the entire filtration allows for a high quality product and prevents postclouding problems. This solution enables a perfect functioning of the process under all conditions, including operation in difficult regions such as tropical countries”. With this type of application it is possible to avoid direct costs for diatomaceous earth, discharge of fat particles in oily earth or pollution of used earth if any. But, above all, the stearins and extracted waxes are pure and can be used as raw materials in the food as well as in the cosmetic and pharmaceutical industry.
Filtration of extravirgin olive oils
The best-selling filter-press in the food oil filtration field has always been the clarifying filter Clearness, which today has reached the sixth generation. Clearness 6 is the clarifying filter designed and manufactured to increase the filtration efficiency of extravirgin olive oils, crude or refined, and of all food oils before bottling.
The filtering element, composed by carton pads of various thicknesses, is kept in its position by plates or frames that can be made of polypropylene, aluminium or stainless steel according to structural solutions that enhance its efficiency. “An exclusive feature that has always characterised our clarifying filters is the realisation of plates and frames without the use of elastomer seals (NBR, Viton) – explains Fabio Donzella. – Besides not binding the user to a precisely defined thickness of carton pads, this type of solution notably facilitates maintenance operations. Another fundamental, distinguishing aspect is the housing of the whole plates-frames-carton pads package inside a sealed tank that acts also as an integral casing. This device, besides representing an essential safety system for the compliance with the machine directive in force on a European scale, provides the user with a useful instrument to avoid contact of the product with the external environment, preserving the quality of the food oil and turning into a fundamental hygienic element”. In the semi-automatic version, the standard machine is composed as follows: stainless steel structure like the housing tank of the filtering pack; sliding cover fitted in the upper part of the structure; filtering pack composed by polypropylene plates and frames and carton pads or filtering layers; two stainless steel valves; a transparent flow indicator; a stainless steel valve for the oil recovery from the tank; a manometer. An optional that only Galigani Filtri supplies is the pressing system for the used carton pads, directly installed on the clarifying filter. This device allows recovering most of the product retained in the carton pads used in the previous filtration session, making them drier and easier to manage.
