Foods and beverages: apparatus – Means to treat food – By isolating a fluid constituent
Patent
1996-03-06
1998-04-14
Alexander, Reginald L.
Foods and beverages: apparatus
Means to treat food
By isolating a fluid constituent
99510, 100112, A23N 100
Patent
active
057380031
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to an improved counter current extractor having improved flow characteristics.
BACKGROUND OF THE INVENTION
Counter current extractors (CCE's) are well known in the food processing industry for the continuous extraction of liquids, solubles, and fine particulate matter from associated solids. Such extractors may comprise a screw conveyor or pair of parallel counter rotating screw conveyors mounted within an inclined or vertical elongate housing, which takes the form of a trough or enclosed tube. Material to be processed is fed into the lower end of the housing and carried upward by screw rotation while an extracting liquid is fed into the top of the housing via spray jets and flows downwards under gravity. An example of this type of extractor is found in U.S. Pat. No. 4,363,264, which is incorporated herein by reference.
When the solid phase material reaches the top end of the housing, it is removed from the housing, either by a slat-type conveyor, or by being pushed up a ramp by the material being expelled behind it. The solid phase material may be pressed to remove liquid entrained therein, and this liquid is returned to an intermediate position of the CCE trough.
Generally, strainer means are provided to filter large particles of the solid phase from the extract liquid prior to its removal from the lower end of the housing. Problems have arisen in the past with particles of solid matter being trapped against the strainer means by the pressure of liquid flowing through the strainer means, thus blocking flow. This is particularly so where the material to be processed is added cold, so that increased quantities of hot recycle liquid are required to heat the material to improve extraction.
Another problem which arises from increased extracting liquid flow is the tendency of the solid phase to disintegrate under the higher spray pressure of the extracting liquid as it enters the CCE extractor. This contributes to the amount of small particulate matter within the extractor which causes blockage of the strainer means. In addition small particulate matter can create a blockage or reduce the porosity of the solids phase itself through the entire length of the CCE. This in turn reduces the flow rate of the liquid phase down the CCE in relation to the flow rate of the solid phase moving up the CCE, resulting in a high liquid retention level throughout the CCE causing the liquid to by-pass the solid phase resulting in higher dilution and lower yield.
Whilst it is desirable to ensure that the liquid phase passes freely through the retaining means, it is also desirable that a controlled amount of liquid be retained in the lower regions of the housing to enhance the solid/liquid contact in the vicinity of the solids charging point. In many, if not all applications, when solids are first added to the CCE, there is a net uptake of liquid into the solid phase, resulting in an increase in mass and volume of the solid phase. Whilst not wishing to be bound to any theory of operation, it is believed that where fruit, for example, enters the CCE with live, intact cell walls, osmotic pressure drives water into the cell, whilst the still organised cell wall ejects soluble compounds into the extracting liquid. After an initial uptake of water, lysing of the cell due to heat occurs, releasing the cytoplasm and added water. A similar effect is noted for dry material such as coffee beans, due to the hygroscopic nature of the material, rather than osmosis. No subsequent release of water occurs in this case.
The transfer Of liquid into and out of the solid phase is believed to have a significant effect on both concentration of the extract and the yield of soluble components transferred from the solid to the liquid phase. By controlling liquid level during the early processing of the solid phase, improved extraction can be achieved.
SUMMARY OF THE INVENTION
The present invention seeks to provide means for alleviating or overcoming one or more of these problems. Accordingly, there is provided a CCE ha
REFERENCES:
patent: 2587556 (1952-02-01), Veiss et al.
patent: 2629663 (1953-11-01), Fogler et al.
patent: 2793582 (1957-05-01), Rothe et al.
patent: 3529938 (1970-09-01), Yoon et al.
patent: 3726209 (1973-04-01), Stoltze et al.
patent: 3857332 (1974-12-01), Houghton-Larsen et al.
patent: 4289579 (1981-09-01), Forsberg
patent: 4363264 (1982-12-01), Lang et al.
patent: 4705055 (1987-11-01), Rohm et al.
Alexander Reginald L.
Processing Technologies International Limited
LandOfFree
Counter current diffusion extractor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Counter current diffusion extractor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Counter current diffusion extractor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-627208