US2764474A - Apparatus for the continuous lixiviation, extraction or the like of vegetable material - Google Patents

Description

sept. 25, 1956 l K GUNKA I2,764,474r

APPARATUS FOR THE CONTNUOUS LIXIVIATION, EXTRACTION v OR THE LIKE OF' VEGETABLE MATERIAL Filed Nov 19, 1953 2 Sheets-Sheet 1 sem. 25, 1956 764,474

GLINKA 2, APPARATUS FOR THE CONTINUOUS LIXIVIATION, EXTRACTION OR THE LIKE OF VEGETABLE MATERIAL Filed Nov 19, 1953 2 Sheets-Sheet 2 L/QU/D FLOW Patented Sept. 25, 1956 APPARATUS FOR THE CONTINUOUS LIXIVI- ATION, EXTRACTION R THE LIKE 0F VEGETABLE MATERIAL Karl Glinka, Krefeld-Uerdingen, Germany, assgnor to Buttner-Werke, A. G., Krefeld-Uerdingen, Germany Application November 19, 1952, Serial No. 321,468 Claims priority, application Germany November 21, 1951 2 Claims. (Cl. 23-270) This invention relates to an apparatus for continuous lixiviation, extraction, or the like. The invention is particularly applicable to the lixiviation of vegetable matter such as, for instance, beet cossettes and oil seeds and the like.

One object of the invention is the provision of means by which continuous lixiviation is accomplished and by which the amount of liquid required for substantially complete lixiviation of a given quantity of solid material is less than that required hitherto and commonly used. The liquid extract obtained thus has a high concentration and in many cases, such as for instance in the production of raw juice for sugar-making, concentration by evaporation, which has had to be carried out hitherto, will no longer be necessary.

Apparatus known hitherto is unsatisfactory in this respect. One such apparatus consists of a tower-like processing chamber fitted with a spiral or screw-conveyor for the material. By using apparatus of this kind, the extraction liquid, which is drained off at the bottom and correspondingly replenished from above, occupies practically the whole processing chamber, lwhere it forms a liquid column. Such screw-conveyor carries the material through the liquid from the bottom to the top of the chamber. With this apparatus, however, mixing-up of liquids of dilerent concentrations cannot be avoided. It is a well known fact that such conveyors always cause the material being conveyed to ball up, that is, to become packed solid. Such balling-up must be prevented at all costs, if the lixiviation action is to be carried out uniformly and thoroughly.

It has also been suggested that the liquid should be passed through a number of separate compartments, the material to be treated being passed through these compartments in a counter-current. A well known construction for carrying out this proposal is a rotary drum which is tted with spirals. The spirals cause the liquid in the drum to be divided into several batches separated from one another. With an apparatus of this kind, however, the distance over which the liquid has to travel depends upon the length of the rotary drum and, therefore, is extremely limited.

With one material treated by this last mentioned method, it was found that the time of contact between the material and the liquid required some 30 minutes, with a treating path-length of 400 metres, or more, which, when practiced with previously known methods and apparatus, such apparatus requires treating chambers cf great area occupying a great area in a plant or building.

Now, the present invention provides a lixiviating apparatus by which the material, to be treated, is continuously and positively carried upwardly along a spiral path and extracting liquid is allowed to ow downwardly along the same path in a continuous stream in counterflow to the movement of the material to contact and be obstructed by the same, the speed of movement of the material, and the rate of ow of the liquid and the pathlength being so chosen that the material is in contact with the liquid for the length of time necessary for lixiviation to be substantially completed and the area of the processing chamber or tower being substantially less than that required by hitherto known methods and ap* paratus.

By using the apparatus according to the present invention, an optimum gradient is obtained between the degree of saturation of the liquid and the substance-content of the material undergoing treatment.

It will be understood that the transition, from the high substance-content of the fresh material to the low content of the spent material and from the low concentration of the fresh liquid to the high concentration of the liquid end-product, takes place substantially uniformly over this l-ong distance. The fact that these transitions take place over such a long distance ensures thorough lixiviation.

One form of apparatus for carrying out this invention comprises a xed upwardly spiralling trough, means for feeding the extracting liquid to the upper end of the trough and means for carrying the material upwardly along the spiral trough to travel through the liquid.

The form of apparatus referred to above have the great advantage that it is possible for the material to be treated to travel through the current of liquid in a loosened condition. This is' not possible to the same extent in, for instance, the previously known tower-like apparatus employing a screw-conveyor.

The lixiviation provided by the present invention will now be more fully described with reference to the accompanying drawings which show, by way of example, two forms of apparatus adapted to carry it out.

In the drawings:

Figure l is a vertical sectional view of one form of lixiviating apparatus;

Figure 2 is a section on the line 2 2 in Figure 1;

Figure 3 is a side View of a part of the extraction trough of another slightly modied form of apparatus; and

Figure 4 is a section on the line 4 4 in Figure 3.

Referring rst to Figures l and 2, a fixed spiral trough 1 extends vertically within an annular treating chamber C of a tower T. The material being treated is moved upwardly along the trough in wire-net baskets 2 which are caused to travel through the trough from the bottom to the top. In order to simplify the drawing only one of the wire-net baskets is shown but it will be understood that baskets are arranged along the whole length of the trough. The wire-net baskets 2 are supported by cross-bars 3, the ends of which are tted with ball-bear ing wheels 4 which roll on track rails 5 secured to and disposed around t-he vertical wall of the treating chamber C between the convolutions of the trough 1. The transportation of the wire-net baskets in an upward spiral path in the treating chamber is effected by means of an endless chain 6, the links of which pass around a rotary cage 7 which form the inner circumferential wall of the annular treating chalmber C. As the cage 7 is rotated by means of driving gear (not shown), which may be of any suitable known type, the chain is driven in its turn and causes the forward movement of the cross-bars 3 and thus the transportation of the wire-baskets 2. After travelling over the whole length of the spiral trough ll from the bottom to the top, the endless chain 6 carries the baskets over guide pulleys 14 and on their way dow-n the baskets tip their contents int-o the shaft o1' chute 8, the empty baskets being carried back again to the feed end or loading station 9 by the chain 6 passing over the pulley 14a, through the horizontal housing Sa and up and over the pulley 14h. The feeding device, which consists of a hopper lll, a vibratory conveyor 11 and a feed chute l2, ensures uniform filling of the baskets. After it has been lled, each basket is re-introduced automatically into the processing chamber.

The lixiviating liquid is admitted to the trough l from above through an arrangement 13 including a regulating valve and supply pipes, and it flows in a continuous uniform stream in a downward spiral.v Thus upon introduc- -tion into the trough, fresh liquid is first brought into contact with the material which has already been thoroughly liXiviated. On the other hand, at the lower end ot the trough the fresh material comes into contact with the liquid which is already highly concentrated. The length of the spiral trough, the speed of the movement of the material and the rate of flow of the liquid are such that the material is in contact with the liquid for the length of time necessary for lixiviation to be substantially completed. v

It will be understood that means may easily be provided for raising the temperature of the liquid at certain points in its downward path, if this should be necessary.

The endless chain 6 returns to the lower end of the treating chamber C from the loading station 9, the lower part of which being connected to the loading station 9 by a horizontal casing. This arrangement enables the material to be processed in a continuous manner while at the same time facilitating 4the exclusion of atmospheric arr.

Referring now to Figures 3 and 4, in an alternative form of apparatus for carrying out the invention, the material, to be treated, is divided -into batches or masses carried in wire-net baskets which are of flattened shape, their thickness in the direction of movement being small relatively to their breadth and depth, so that they can be regarded as being arranged edgeways. The masses of material to be treated are moved in the opposite direction to the flow of the liquid so that they act as dams, holding back the liquid and thus forcing it to permeate the material, overcoming the resistance of the material itself. Moreover, this resistance varies with the relative speed of the material and liquid. Thus, although the pathlength is shorter than in the embodiment previously described, the liquid is nevertheless in contact with material for a sufficiently long time to ensure that liXiviation is substantially complete. The spaces 16 left between the various layers or masses of material form reservoirs for the liquid, the level of the liquid in each space 16 being lower than that in the preceding space. pends upon the inclination of the trough 1.

If necessary the resistance of the masses of material to the flow of liquid can be augmented by fitting bales The amount of this difference in level deon the baskets 15. In one such construction the baffles on alternate baskets are staggered relatively to one another so that the liquid ows in a zig-zag fashion along its spiral path. In another construction alternate baskets carry pairs of bafiles near their outer edges and single baflles at their centres. In this case, the stream of thc liquid is deflected alternately from the centre to the edges of its spiral path and vice-versa.

The constructions described above are, of course, given by way of example only. They can be modified in many ways within the scope of the invention as defined by the claims. For instance, instead of providing wirenet baskets for carrying the material, as hereinbefore described, the means for moving the material may comprise rakes or Scrapers which cause the material to slide along a stationary trough.

Furthermore, the trough need not be stationary.

l claim:

l. A lixiviating apparatus of the character described comprising a housing forming a treating zone, a trough mounted within the housing defining a vertically disposed spiral path from substantially the top to substantially the bottom of the housing, means to introduce a lixiviating liquid into the upper end of the trough for downward ow along and over said spiral path, and means for positively carrying the material to be treated in successive and continuous amounts and mounted in the housing to transport said material from the bottom end of the said spirial path upwardly along the length of said spiral path and through and in opposition to the downwardly fiowing liquid means for actuating said carrying means.

2. A lixiviating apparatus as defined in and claimed by claim l wherein the trough is fixedly mounted in the housing and wherein the carrying means for the material to be 'treated include a successive series of flat foraminated containers permeable by said lixiviating liquid and mounted to move upwardly along and over said spiral path and arranged edgewise to the flow of the liquid downwardly over the said spiral path, and said actuating means including means connecting said containers in a continuous series.

References Cited in the file of this patent UNITED STATES PATENTS 1,132,172 Duncan Mar. 16, 19l5 2,199,928 Van Wirt May 7, 1940 2,273,557 Bonotto Feb. 17, 1942 2,512,710 Beeson June 27, 1950 2,545,938 Bilbe Mar. 20, 2,638,409 Bottaro May l2, 1953

Claims (1)

1. A LIXIVIATING APPARATUS OF THE CHARACTER DESIRED COMPRISING A HOUSING FORMING A TREATING ZONE, A TROUGH MOUNTED WITHIN THE HOUSING DEFINING A VERTICALLY DISPOSED SPIRAL PATH FROM SUBSTANTIALLY THE TOP TO SUBSTANTIALLY THE BOTTOM OF THE HOUSING, MEANS TO INTRODUCE A LIXIVIATING LIQUID INTO THE UPPER END OF THE TROUGH FOR DOWNWARD FLOW ALONG AND OVER SAID SPINAL PATH, AND MEANS FOR POSITIVELY CARRYING THE MATERIAL TO BE TREATED IN SUCCESSIVE AND CONTINUOUS AMOUNTS AND MOUNTED IN THE HOUSING TO TRANSPORT SAID MATERIAL FROM THE BOTTOM END OF THE SAID SPIRIAL PATH UPWARDLY ALONG THE LENGTH OF SAID SPINAL PATH AND THROUGH AND IN OPPOSITION TO THE DOWNWARDLY FLOWING LIQUID MEANS FOR ACTUATING SAID CARRYING MEANS.

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