D E S C R I P T I O N

The present invention deals with a distributing and treating system for centrifugal machines for passing and refining food products, such as fruit, tomatoes, vegetables, meats, etc.

Commonly, the above machines are composed, in their essential parts, of a cylindrical or conical sieve made of drilled sheet or net and of a rotating member inside the sieve which is composed of a series of vanes or bars keyed onto a hub or shaft.

Vanes or bars are generally slanted in order to enable the advancement of waste products towards the outlet.

The prior art consists in inserting the product to be separated inside the sieve by means of one or more loading openings; then, the rotating part individually fetches an indefinite part of the product and impresses thereon a rotating and translating motion along the sieve, generating the separation of part of pulp and/or juice from the sieve periphery due to a centrifugal effect, while the remaining product inside it is disposed of, once having reached the outlet opening of the centrifugal machine.

In known machines, in which vanes have a height of about 5 cm., between two contiguous vanes a product heap is created which is not homogeneously treated, bringing about the below-listed inconveniences.

Inconveniences which can be pointed out from current ait are as follows:

1. Non-homogeneous product squeezing generated by the strong rotation speed

(about 1000 rpm) impressed to vanes, with the consequence that, during the process, the product is not completely squeezed or, on the contrary, is squeezed too much;

2. Passage of waste product parts through the sieve holes due to the abrasive effect impressed by the centrifugal motion against the filtering wall;

3. Efficiency reduction of the passing machine;

4. Quality reduction of obtained pulp and/or juice.

Object of the present invention is avoiding the above listed inconveniences and making a machine available which allows a better product distribution on vanes or bars and a better product treatment in the rotor, obtaining separation of juice and/or pulp with lower rotor rotation speeds, simultaneously increasing quality and amount of extracted products.

In order to solve the above-mentioned inconveniences, the technical problem that the present invention solves is creating a layer of thin material adhering to the sieve.

The advantages obtained with the proposed system are listed below: • Uniform product squeezing and separation;

• Removal of waste passage through sieve holes, due to product abrasion;

• Rotation speed reduction (about 1000 rpm in known machines) with consequent electric energy absorption reduction;

• Uniform characteristics of the obtained product (juice and/or pulp). The above objects and advantages are all obtained by a distributing and treating system for centrifugal machines, which is the subject matter of the present invention, which is characterised by what is provided in the below-listed claims, and particularly in that it provides for the creation of a thin layer, less than 15 mm., of product adhering to the sieve.

These and other characteristics will be better pointed out by the following description of some embodiments shown, merely as a non-limiting example, in the enclosed tables of drawing, in which:

- figure 1 sectionally shows a centrifugal passing and refining machine with the distributing and treating system of the invention;

- figure 2 shows part of view "A" in the previous figure, specifically an appendix section of the distributing disk;

- figure 3 shows from the top a view of the rotor vane of the machine in figure 1;

figure 4 shows section B-B of figure Jl showing a vane with attached cutting blade of the product to be passed and refined; figure 5 shows in a section like figure 4 a vane according to a possible variation. With reference to figure 1, reference 1 designates a centrifugal passing and refining machine which is composed of a shaft 2 on which a rotor 3 is approximately centrally assembled, a plurality of vanes 4, arranged radially, being screwed onto such rotor 3.

Every vane 4 extends till it licks the internal surface of a sieve 6 made of drilled sheet or net, which is coaxial and concentric with the rotor 3. The sieve 6 allows separating juice and/or pulp from the product.

The machine is equipped with one or more inlet openings 7 and, on the opposite part, with two outlet openings 8 and 9, one for juice or pulp obtained from the process (opening 8), the other one for the squeezed waste product (opening 9).

The machine 1 is closed by a carter or a casing 10. In the example a distributing disk 11 is also shown, with conical appendix secured to the shaft 2 and placed at the product inlet and equipped with (see also figure 2):

• a series of holes 11a, placed on the cylindrical or conical appendix, having the chance of registering the section area, as described below, of the passage surface depending on the operating flow rate of the centrifugal machine 1 and on the number of bars or vanes 4 of the rotor 3;

• a series of vanes 12, radially arranged to the disk 11 axis, in order to provide, when rotating, a centrifugal thrust onto the product and aid product output from the above described holes 11a.

As regards the registering system for the holes 1 Ia, it must be observed that, below the distributing disk 11 appendix, a ring 13 is assembled which has a plurality of laminations 14, preferably one for every hole 11a of the disk 11.

Function of the plurality of laminations 14 is adjusting the product passage section through the holes 11a: an adjustment of the angular position of the laminations 14 with respect to each hole 1 Ia will determine a more or less wide area of actual passage of the products. Preferably, the number of holes 11a is equal to the number of vanes. Preferably, the disk 11 is placed so that the holes 1 Ia are next to the series of bars or vanes 4, so that the product is immediately taken by them and consequently the distribution is optimised in the rotor 3.

Due to the effect given by vanes 12 and adjustable holes 11a, an enough accurate product distribution is obtained on the rotor 3 thereby avoiding the different product squeezing degree.

The product treating system of the present invention is shown in figures 3 and 4, in which it is observed that, on each bar or vane 4 of the rotor 3, there is an appendix or blade

15, arranged substantially perpendicularly to the surface of the vane 4 itself, inserted in order to keep a uniform product thickness in front of each vane 4 of the rotor 3, immediately below the internal wall of the sieve 6.'

The blade in the example is shaped as a "L", however its embodiment can be subjected to numerous shape variations without departing from the major inventive idea which is, as already stated, to create a brake in the product contained between two adjacent vanes 4. The thickness created by the blade 15 must be as minimum as possible, less than 15 mm., depending on the treated product so that the position of the blade 15 can change along

1 the radial direction of the vane 4, for example by inserting a series of pre-established holes 16 on the blade 15.

Moreover, the blade could have a surface 15 which extends to the rotor 3 and goes on, bent, till it is inserted below the vane 4 and is secured together with it through the coupling 17.

The distance from blade to sieve surface is less than 15 mm.

As better shown in the top view of a single vane 4 of the rotor 3, the blade has a series of interruptions, in the example the holes 18, to aid the product output on the whole length of the bar or vane 4. Preferably, the holes 18 are concentrated in the second two thirds of the vane length

(along the product advancement direction).

The presence of the constant product thickness between blade 15 and sieve 6 allows performing the process with a lower rotation speed, and therefore with a lower product pressure on the sieve 6, due to the combined action of centrifugal force and reduced product weight.

The final result is that the product is treated very delicately, there are no waste passages due to product abrasion in pulp and/or juice, and moreover the electric power absorbed by the machine is reduced.

In the example, an explicit reference has been made to a distributing disk 11 with conical appendixes, but it is obvious that such shape does not characterise the member, which can have, for example, cylindrical appendixes.

Moreover, the present system can be applied to centrifugal machines with sieves with a conical shape and/or rotors with polygonal or conical section.

According to a possible embodiment shown in figure 5, the thin product layer adhering to the sieve can be also realised by reducing the vane height down to a value which is less than 15 mm.

It has been observed that the ideal number of revolutions of the rotor is included between 200 and 250 rpm, and this allows reducing the installed machine power.