Apparatus for continuously and uniformly coating confectionary products

The present invention relates to machines for coating uniformly continuous, confectionary products comprising a solid core, or gelatinous, or paste wrapped in one or more uniform layers, of one or more liquid and / or pulverulent by eg sweets, biscuits appetizer, exploded cereals etc.

Manufacturing some sweets, especially those with a core of gelatin, includes an operation in which said core is moistened evenly with a liquid, colored or not, and powdered sugar particles are uniformly adhered to the moist layer .

These coating operations are delicate. It is necessary that the coating layers are uniform over the entire periphery of the core. Do not crush or break the soft cores. We must prevent the nuclei from sticking together.

To date, coating operations are performed in a tank or a hemispherical or cylindrical container which is rotated about its axis at relatively low speed and which is designated in the trade under the designation turbine.

a certain quantity of product is placed in the vessel to be coated, e.g., cores in gelatin and is poured into the vessel as it rotates, one or more liquid, colored or not, which uniformly permeate the gelatin cores then the sugar powder which can be stuck on the periphery moistened nuclei to form a uniform coating.

In the tank, the cores rotate on themselves, so that the liquid and the sugar particles are uniformly distributed at the periphery of each core.

After a stirring time, it stops rotating in and out of the tank coated products.

This technique is well developed and it provides a good uniform coating without altering products such as gelatin relatively fragile cores. However, this technique has the drawback of being substantially discontinuous.

Was chosen by way of example the coating of candy coating but the same problem arises in other production cycles.

For example, many of aperitif biscuits are made by extruding dough through a die following which the dough pieces are moistened with a liquid and then sprinkled with salt, sugar and spices.

Patent GBA 856 763 (The City Bakeries) discloses an apparatus for coating of sugar confectionery products which is composed of an auger turning in a trapezoidal trough. The screw is composed of rods which are located radially on a shaft and which bear son helically wound.

US Patent 1,893,672 (LG James et al.) Describes a machine to manufacture candy that has a helical brush in turning an oscillating trough having a perforated bottom.

The combined action of the brush and oscillating trough used to remove excess starch.

U.S. Patent 1,374,938 (DH McNulty) discloses a machine for coating with sugar candy.

This machine comprises a rotatable cylindrical screen which rotates within a trough. The machine has an internal screw without a sieve and external screw fixed to the screen.

The objective of the invention is to provide machines for coating continuously and uniformly confectionary products comprising a solid core, gelatinous or paste coated in a liquid product and / or powdered.

A machine according to the invention is of the known type comprising a fixed chute is substantially horizontal, a worm which is driven in rotation in this trough and means for introducing into the chute the cores to be coated and the liquid and / or pulverulent .

The objective of the invention is achieved by means of a machine that includes one or more helical brushes which are composed of bristles implanted radially helically on one or two drive shafts which are driven in rotation in said trough at a speed less than 100 revolutions / minute and said spout has the shape of a trough which is upwardly open, which has a height greater than the diameter of said brushes and which has a cylindrical bottom which envelops said brushes in the part located below said drive shafts.

According to a preferred embodiment, a machine according to the invention comprises two helicoidal brushes of same diameter, composed of bristles implanted radially helically on two parallel drive shafts which are driven in reverse rotation to each other and such that the bristles of the two brushes move upwardly in the central part of the trough.

The invention results in the continuous coating in products such as sweets, appetizer cookies or similar products that require coating operations or dusting.

The method according to the invention allows to build automated continuous plants and fewer handling and hand of work therefore the cost of manufacturing.

The coating is as uniform as that of the products manufactured batchwise in the rotating drums called turbine used commonly to date.

This result is due to the fact that the products to be coated that are discharged into the trough of a machine according to the invention rotate endlessly on themselves, while they are moved by the helical brush.

It is found that being coated products form between each pair of threads of the helical brush, a small package that runs continuously on itself in a tight space and at the same time, each core also turns on itself inside the package, so that the impregnation of the cores with a liquid and then by solid particles is uniformly distributed over the entire periphery of each ring.

The rotation of the cores packets and nuclei within packets is due to the thrust of the bristles on the cores. As these hairs are flexible, this pressure does not deteriorate the cores and not even deforms if it is soft cores gelled or pasty.

The bottom of the trough is cylindrical and the bristles of the brush rubbing against the walls of the trough, which has the effect of sweeping them and prevent deposits are adhered.

The side walls of the trough are vertical or slightly diverging towards the outside, so that the nuclei which are entrained by the brush along the cylindrical wall and then beyond the brush can not follow the vertical wall and fall into the bottom of the trough. ---- Finally it occurs in each interval between two successive threads of the screw a similar mini-turbine effect to that obtained in batch turbines used today.

A machine according to the invention can be used to coat all kinds of products, for example to coat almonds, hazelnuts or peanuts. In this case, one starts by wet the roasted fruit with a fixing liquid, for example an alginate or oil liquid, and then sugar or salt is sprinkled.

The machines according to the invention having two helical brushes not reverse, mounted on two parallel shafts, have the advantage that being coated products accumulate between the two brushes where intense mixing effect occurs such products without these do come into contact with walls of the trough.

The machines according to the invention comprising one or two curved side walls which extend the semi-cylindrical bottom of the trough above the horizontal plane in which lies the axis or the axes of the drive shafts have the advantage of eliminating the need to mount these shafts on bearings and prevent self-saturation phenomena of the machine where the product flow to be coated is greater than the transport capacity of machine.

The machines according to the invention comprising one or two drive shafts each carrying bristles which are located on said shaft in two parallel and intercalated helices, can increase the throughput of the machine without increasing the rotation speed.

The machines according to the invention equipped with a spray bar or any other equivalent means for distributing a cleaning liquid are self-cleaning machines that can quickly switch production from one product to that of another product.

The following description refers to the accompanying drawings which show non-limiting, exemplary embodiments of the invention machine.<ul><li>Figure 1 is a longitudinal section through a coating machine according to the invention.</li><li>Figure 2 is a partial perspective view of the front end of the same machine.</li><li>FIG 3 is a view of a second machine part to be coated above the invention.</li><li>Figure 4 is a transverse section along IV-IV of Figure 3.</li><li>Figure 5 is a cross section of a machine embodiment according to Figure 3.</li><li>Figure 6 is a cross section of another embodiment of a machine according to Figure 1.</li><li>Figure 7 is a partial top view of a third machine of the invention.</li><li>Figure 8 is a cross section of a machine according to the invention for manufacturing exploded grains.</li><li>Figures 9 and 10 show respectively a top view and a cross section along XX of a variant of construction of a machine according to the invention.</li><li>Figures 11 and 12 show respectively a top view and a cross section along XII-XII of a head cores feeding device of a machine according to the invention.</li><li>Figures 13 and 14 show respectively longitudinal and transverse cuts along XIV-XIV of a machine part according to the invention for cooking food products in an oil bath.</li><li>Figures 15 and 16 show respectively a top view and a cross section along XVI-XVI of a machine according to the invention for manufacturing exploded grains.</li><li>Figures 17 and 18 show cross sections of machines according to the invention.</li><li>Figures 19 and 20 show a top view and a cross section of a machine embodiment according to the invention.</li></ul>

The different figures represent coating machines for continuous solids with liquids such as a sugar syrup, honey or oil and / or powdery products such as salt, sugar, cocoa conditions such that the solids are uniformly coated with the liquid and / or pulverulent.

The machines according to the invention are used especially in the manufacture of confectionery products such as sweets, savory or sweet biscuits, dried fruit coated with sugar or salt, and in general, any product with a solid core, pasty or gelatinous material to be uniformly wetted and / or uniformly coated with one or more layers of a powdery product.

The machines according to the invention can be used in addition to manufacturing products that require cooking step, eg broken grain type popcorn or the like.

Figures 1 and 2 show a machine which comprises a rectilinear trough-shaped chute 1, consisting of a cylindrical wall 2, in the form of a semicircle extended by two side walls 3d and 3g, which are vertical in Example represent.

Alternatively, the side walls may differ slightly outward while remaining adjacent to the vertical. The trough 1 is open to the top and at the front end.

A machine according to the invention further comprises an endless screw which is composed of a drive shaft 4 and a helical brush 5, consisting of flexible bristles, e.g., bristles or synthetic fibers which are implanted helically on the shaft 4. both ends of shaft 4 are supported by bearings 6, for example by bearings which are arranged such that the shaft 4 and the semi-cylindrical bottom 2 of trough are substantially coaxial. The length of the bristles of the brush 5 is slightly greater than the radius of the half-cylinder 2, so that the bristles rub against the cylindrical walls of the trough. The total height of the trough 1 is of the order of 1.5 times the diameter of the helical brush. The shaft 4 is rotated at a slow speed less than 100 rpm by an electric motor 7 and a transmission 8, for example a transmission belt and pulley in the direction such that the products are discharged into the trough are driven toward the end thereof.

A chute 9 is located above the trough 1, near the rear end, and flows therein for products to be coated 11, for example cores gelatin jellies or exiting of dough an extruder for manufacture of aperitif biscuits.

Reference numeral 10 represents means for injecting into the trough of various liquid or pulverulent products. For example, in the case where one must impregnate candy, is first injected colored liquid used to moisten the gelatin core to soften it and to color. then injecting powdered sugar which can be stuck on the surface moistened on which it is to form a uniformly distributed coating.

The chute 9 and the distributors 10 continuously deliver a constant flow rate and the auger rotates continuously, so that the coating operation is continuous.

The cores 11 that fall into the bottom of the trough formed in the intermediate space between each pair of threads of the endless screw, a small package 12 cores. This package is pushed forwards by the worm.

The cores 11 that are in contact with the bristles of the rotating brush are driven upwardly along the cylindrical wall of the trough. When they arrive at the drive shaft 4, they are no longer driven and they fall back towards the inside of the trough under the thrust of those which lie below them and which are driven to the top.

This means that each pack 12 continuously rotates on itself as it advances and also each core volume in all directions inside the package that contains it. There is obtained an identical mixing effect to that which occurs in the staple turbine used to date to make uniform coatings.

The method according to the invention has the advantage of being continuous. Is collected at the exit of the trough a steady stream of products coated 13.

A machine according to the invention may comprise several troughs cascaded and each equipped with a worm screw, so that the products leaving a trough fall in the following. Such a machine enables the manufacture of coated products which must comprise several successive coating films of different nature such as dragees or pills. In this case, the hardening of coating layers is accelerated by projecting onto the moistened products a stream of hot air at the outlet of each trough.

As the bristles of the brush 5 helical rub against the inner wall of the trough 1, they continuously scan the wall, which prevents deposits from adhering thereto. This brushing function of the wall is very important because it encapsulates most often with sweet juice that tend to stick to the walls and to give birth to a solid crust and brushing prevents the formation of such a crust, which would not be possible with no rigid screw should be separated from the wall by a game in which deposits would form themselves.

Compared with a rigid screw without a machine according to the present invention comprising a helically brush the advantage that the action of soft bristles on the cores to be coated which are generally soft will not distort them or the scratch, which would lead to production rejects.

Figures 3 and 4 show a second machine according to the invention which comprises a straight trough 14 open upwardly and at the front end and two spiral brushes 15d and 15g which are parallel to each other. Each helical brush comprises a rigid straight drive shaft, respectively, 16d and 16g and bristles 17d, 17g implanted helically on said shaft to form a helical brush. The bristles may be bristles animals, plant stems, synthetic fibers or metal son.

The two propellers have no equal and opposite direction. The arrow F represents the product travel direction to be coated. The solid cores of these products are discharged into the trough near the upstream end thereof and they are moved in the direction of the arrow, forming clusters 18 ball shaped rotating on themselves same time they advance, which has the effect that each core is uniformly coated with the liquid and / or pulverulent solids which are discharged into the trough.

4 shows a cross-section facing downstream, that is to say looking in the direction of product movement.

It is seen in Figures 3 and 4 that the propeller 15g, to the left of the figure, has a pitch to the right and is rotated in the opposite direction to the pitch, that is to say in the opposite direction to that of clockwise.

The screw 15d on the right side has a left-hand and it is rotated in the direction of clockwise with the same absolute speed.

Both propellers are arranged symmetrically with respect to the longitudinal median plane, that is to say substantially in antiphase with each other and are substantially tangent to one another in the median plane.

We see in Figure 4 that the bristles of the two brushes located between the two drive shafts 16d and 16g, in the part where the two brushes are tangent, moving from bottom to top and it is in this part that products to be coated that are raised by the brush bristles and which fall when they escape thereto accumulate to form a pile 18 which is driven by a rotational movement on itself. As seen in Figure 3, is formed in the space delimited by the two drive shafts 16g and 16d a series of clusters 18 each located downstream of a point of tangency of the two brushes and each of these cluster performs a function of miniturbine which circulates continuously the products to be coated from one end to the other of the trough 14 where they are discharged.

Advantageously, as seen in Figure 4, the bottom of the trough 14 consists of two side by side cylindrical portions 19g and 19d which each envelop a part of the periphery of a screw to the level of plane PP 'in wherein lie the axes of the shafts 16g and 16d and which extend above the plane PP 'by walls 20d, 20g vertical or inclined.

two half cylinders 19g and 19d are symmetrical relative to the median longitudinal plane and they overlap therein forming a central ridge 21 which engages between the two propellers remaining tangent thereto.

5 shows a cross section of an alternative embodiment.

Parts similar are represented by the same reference numerals in Figures 4 and 5. The helices are identical.

The two side walls 20d and 20g of the trough lying above the plane PP 'have the form of cylindrical portions which extend the cylinder portions 19d and 19g, so that each worm is enclosed over more than half its periphery and preferably three quarters of its periphery as shown in FIG 3. This particular shape of the side walls of the trough has the advantage that the two brushes are held in place in the bottom of the trough by the side walls without it is necessary to mount the shafts 16g and 16d in bearings to prevent the brushes from rising. This eliminates the steps that hinder the movement of products to be coated and which disturb the regularity of product clusters brewing movement.

On the other hand, in case of saturation of the machine, the products to be coated can rise in the vertical portion of the trough between the vertical walls or slightly inclined to the vertical, 22d, 22g, which extend above the brushes.

Products then escape the action of the brushes, thus obtaining a self-regulation of the saturation phenomenon.

The embodiments according to Figures 3 to 5 which comprise two parallel brushes, have the advantage, compared to machines with a single brush, the clusters 18 of products to be coated are located between the two brushes, without any contact with the walls of the trough. This prevents friction against the walls that may damaging some fragile and can cause uneven coating products.

Furthermore, the double helix machines allow to increase the throughput of the machine and the size of products because the space between the two brushes wherein the mass of product 18 are formed and maintained is larger than the space between the hair amount and a side wall of the trough where the products are accumulated in the case of a machine with a single helical brush.

Figure 6 shows a cross section looking downstream, that is to say in the direction of flow of the products, of a machine according to the invention comprising a single helical brush made up of a drive shaft 24 on which is located a helical brush made of bristles 25.

Figure 6 corresponds to a helix having a pitch to the left which is rotated in the direction of clockwise.

The products to be coated accumulating to form a mass 26 along the side wall of the trough 23 which is swept by the brush bristles in the uplink direction. The trough 23 has a bottom 28 in the form of half-cylinder which follows the contour of the helical brush. The side wall 29 of the trough on the side which is scanned by amount is tangentially connected to the cylindrical base 28. The wall 30 of the trough which is swept by the helical brush in the descending direction has the shape of a portion of cylinder which extends the cylindrical bottom 28, such that the trough surrounds the helical brush on more than half of its periphery. Advantageously, the cylindrical wall 30 extends to the vertical of the axis of the shaft 24, so that the trough envelope three quarters of the periphery of the brush.

The cylindrical wall 30 is extended upwards by a flat wall 31 which may be vertical or slightly oblique and which delimits with the wall 29 a channel 32 overcoming the brush. This arrangement has, in the case of a machine with a single brush, the same advantages as the embodiment according to Figure 5.

The helical brush is maintained in the bottom of the trough by the cylindrical wall 30 without the need to mount the shaft 24 in bearings. In addition, in case of saturation, the excess products rise in the chute 32 where they escape the action of the brush and the wall 30 prevents them from being rotated around the shaft 24 and they not join the cluster that precedes them.

Is shown in Figure 6 a cleaning device which can be applied to all machines according to the invention.

This device includes one or more ramps 33, 34 which distribute a cleaning liquid, for example hot water, all along the trough. These ramps may be perforated tubes or tubes equipped with sprayers which propel liquid jet sprayed into the trough.

The machines of the invention, including those used to manufacture sugar-coated products tend to become dirty and must be cleaned after each workstation.

For this, simply start up the ramps 33, 34 liquid dispensers. The bristles of the brush rubbing against the walls are then cleaning brush function and dust are entrained to the outlet of the trough by the helical brush which at the same time conveyor function. This gives with inexpensive means, a self-cleaning coating machine to conduct a high cleaning of the machine after each work station or between different product manufacturing.

7 shows a partial top view of an alternative embodiment of a machine according to the invention.

7 shows an example of a machine having a trough 35 consists of a bottom shaped like a half-cylinder extended by two vertical side walls.

It is stated that the trough could also have the shape shown in Figure 6.

The machines to be coated according to the invention rotate at very slow speeds of between 20 t / min and 100t / min. It follows that their flow is very reduced. To increase throughput, the idea that naturally comes to mind is not to increase, so that the axial velocity of product movement increases.

But not increasing, it leads to increased distance between steps that may contain excessive product clusters that go wrong on themselves, so that the coating is not uniform.

In addition, if the mass of products are too big, they exert a higher pressure against the bristles of the brush and helical as they are flexible, they tend to flex and let out products that meet the clusters located upstream.

7 shows an alternative embodiment which increases the throughput of the machine, without increasing the rotational speed and without increasing the size of individual clusters 36 of products to be coated.

In this embodiment, the machine includes a rigid drive shaft 37 and two helical brushes 38 and 39, and not in the same direction are crossed, that is to say, they are axially displaced half a -not. Thus, every time the shaft rotates one revolution, the machine delivers two clusters 36 but they are separated by a layer of bristles as they progress along the trough.

This gives a better turbine effect. The clusters 36 which are smaller are better stirred and the coating is more uniform.

For the same throughput of the machine, the quantity of products in each cluster 36 is divided by two and each cluster thus exerts a lower pressure on the brush. a higher flow rate can thus be obtained while maintaining a low rotation speed and a uniform coating of products.

It is noted that the embodiment according to Figure 7 can also be applied to a machine according to Figure 3, which would then comprise two shafts each carrying two helical brushes crossed.

8 shows a cross section of an alternative embodiment of a part of machine of the invention for manufacturing cereal exploded like popcorn.

It is recalled that the manufacture of such grain comprises a coating step in oil, optionally the steps of coating in products such as honey or sugar and a bursting step into contact with a heated wall to a temperature between 120 ° and 150 °.

Figure 8 shows a section of the part of the machine structure, in which the break, this part following a portion where took place the coating.

8 shows an exemplary machine having a trough 40 similar to that of Figure 6 and a single helical spiral.

It is stated that this example is not limiting. The embodiment according to figure 8 may also comprise a trough having two flat side walls or a machine according to Figures 3 to 5 comprising two parallel endless screw or a machine according to Figure 7 having two intersecting helical brushes.

The helical brush of the machine according to figure 8 is composed of bristles 41 which are stainless steel wires which are located on a metal drive shaft 42 along a helix having a pitch to the left.

Figure is a view looking in the direction of flow of the products, the shaft 42 is driven in the direction of clockwise.

The trough 40 has a double wall 43a, 43b which defines an intermediate space 44 in which is circulated a coolant such dry steam or oil at a temperature of the order of 150%, so as cereals 45 burst on contact with the hot wall. The mixing of products due to the brush action causes all grains come into contact with the hot wall and burst. Advantageously, the outer wall 43a carries a lagging 46.

Alternatively, instead of using a double-walled trough in which a coolant circulates, one can use a metal trough which is locally heated by flames from burners or electric resistors arranged within an insulated housing .

Is shown in Figure 6 an embodiment in which the vertical wall 29, which is swept by the bristles of the brush in the uplink direction and against which the products accumulate 26 has a rib 47 projecting to the within the chute 32.

This rib is substantially disposed at the upper generatrix of said helical brush 25.

It was noted that the products to be coated which rub against the wall 29 tend to stick against the latter and to continue to ride along the latter under the thrust of new products. There is thus formed in a long tape products adhered to the wall located above the zone which is swept by the brush. The rib 47 prevents the formation of this band of immobilized products against the wall.

Products located below the rib 47 are constantly renewed by new products pushed by the brush.

As regards the embodiment according to Figures 3 and 4, it was seen that the mass of product 18 are formed between the two helical brushes, without being in contact with the side walls of the trough 14. This prevents products from sticking against the wall and move towards the downstream remaining bonded thereto, resulting in a poor coating.

Figures 9 and 10 respectively show a partial top view and a cross section along XX of an alternative embodiment of a coater according to Figure 3.

In this embodiment, the machine includes two helical brushes 49d, 50d 49g whose drive shafts 50g are arranged parallel to the bottom of a trough 51. The arrow F indicates the direction of flow of the products.

The two helical brushes have not reversed. The brush 49d is rotated in the direction of clockwise and it has not left. 49g the brush is rotated in the opposite direction to the clockwise and has a right-hand.

FIG 3 shows a machine in which both brushes are arranged symmetrically relative to the longitudinal median plane MM '. Figure 9 represents a variant in which the two spiral brushes are offset longitudinally with respect to one another.

This provision has the effect of causing a more intensive mixing and better coating products. Solid cores to be coated 52 progressing in the central area between the two helicoidal brushes which move from bottom to top and the nuclei undergo in this area, continual rotational movements in both the longitudinal direction and in the transverse direction which lead to a very uniform coating on all sides of the core.

The intensive mixing of particles is improved by slightly modifying the shape of the bottom of the trough which has, between the two brushes, a rib 53 of rounded shape that facilitates the flow of particles.

Figures 3 and 9 are of the helical brushes which are tangent to the median plane MM '. It is specified that this provision is not exhaustive. The brushes can be slightly apart from the median plane or, conversely, they can slightly overlap the midplane.

The two brushes of a machine according to Figures 9 and 10, which have not and reverse direction of rotation may be rotated either at the same speed or at different speeds to increase the mixing of nuclei.

There is shown in Figures 9 and 10 a machine equipped with a device 81 shaped ridge roof which is symmetrical to the median plane MM 'and which is located above the two brushes. The device 81 avoids projections of products out of the trough and deposit formation against the vertical walls of the trough. The device 81 may be made more removable sections, which allows to remove certain sections where it is desired to introduce products into the trough.

A machine according to the invention is frequently used for coating soft gelatinous or pasty core which are fragile and easily deformable products and the introduction thereof into the machine requires care. Soft cores can not be discharged vertically in the trough because many are embrocheraient on the son of the pin and be broken, which would lead to obtaining an unacceptable finished product.

Figures 11 and 12 show an insertion device of fragile products in the upstream end of a machine according to the invention which comprises a trough 53 and a single helical brush 54 which has a right-hand and which is driven in the opposite direction to clockwise. The upstream end of the trough is located above an endless conveyor belt 55 which moves perpendicularly to the axis of the helical brush. The trough has a lateral opening whose width is substantially equal to that of the conveyor and this opening is located on the side of the trough which is swept by the brush bristles in the downlink direction and it faces the conveyor 55. brush bristles rub against the upper run of the endless belt on which the products 58 are located which are discharged for example via a chute 57. the lower edge 59 of the aperture 56 is placed against the upper face of the conveyor belt . The products 58 are pushed inside the trough by the brush bristles and they gather in clusters in the upper edge of the trough which is swept by the bristles in the upward direction.

Figures 13 and 14 show a longitudinal section and a transverse section along XIV-XIV of part of a machine according to the invention used to cook out continuously in a hot oil bath of food products, for example peanuts or almonds or extruded pasta.

The machine comprises a trough 60 of stainless steel open at the top, in which is disposed a shaft 61 made of stainless steel driven in rotation at a low speed less than 50 revolutions / minute. The shaft 61 carries helical brushes made of flexible stainless steel strands that are located radially and helically on the shaft 61.

The trough 60 has a central section 62 sandwiched between two sections 63a and 63b of smaller cross section to which it is connected by a truncated part.

The shaft 61 carries a helical brush 64 which is disposed along the central section 62 and which comprises steel strands whose length is substantially equal to the distance separating the periphery of the shaft 61 of the bottom of the trough 62 . the shaft 61 carries two helical brushes 65a and 65b of smaller diameter located on either side of the brush 64.

The central section 62 contains in its bottom a hot oil bath 66 which runs preferably against the current direction of movement of goods represented by the arrow F1. The hot bath reaches the bottom of the trough 67a by an entrance and exits through the exit 67b. The circuit in which the oil has a circulation pump, means for heating oil and a filter to stop the suspensions. The height of the oil bath 66 is maintained below the depth of the bottom of the trough 62 relative to the bottoms of troughs 63a and 63b, so that the oil remains in the central trough 62 where the cooking is carried on products. They slowly through the central section 62 being subjected to the action of the helical brush 64 that the advances and submitting them simultaneously to a mixing that drives the products on themselves, so that the even baking is obtained.

A machine according to Figs 13 and 14 can be used to cook or products heavier than oil, such as peanuts, which fall to the bottom of the trough 62, be lighter products which float on the bath surface. Flexible strands steel helical brushes have a triple action of advancement of products, mixing with inversion and continuous purging of the trough walls against which the strands rub.

Figures 15 and 16 show respectively a top view and a cross section along XVI-XVI of another embodiment of a machine according to the invention serves both to be coated and to cook food products for manufacture including Exploded grain popcorn kind.

The manufacture of broken grain has a first operation in which grains of corn, rice or wheat are coated with oil and other commodities such as sugar, salt, honey, chocolate and they are heated to pop them.

Figures 15 and 16 show a machine capable of performing these successive operations.

This machine comprises a first trough 68 which contains a first helical brush, consists of a stainless steel shaft 69 on the stainless steel strands 70 located along a helix having a pitch to the left. The shaft 69 is rotated in the direction of clockwise by a motor 71 at a slow speed, less than 100t / min.

Grain is poured into the trough 68 at the end on the left in the figure and they are moved in the direction of the arrow F2.

During their movement, grains form masses against the side wall of the trough which is swept by the brush bristles in the uplink direction and they rotate on themselves, thereby evenly coat the oil, honey or powdered products such as salt, sugar, cocoa.

The coating of the grain takes place in the section of the trough 68 at the left of the figure and in this section, the trough has an opening at its upper part, wherein the formed cereal clusters and the mixing those as explained previously.

The trough 68 is extended to the right by a section 68a, wherein the grain takes place burst. This trough section has a thick wall a good conductor of heat, for example a copper wall and is heated for example by the flame 72 of a burner or by electrical resistors or any other equivalent heating means to a temperature sufficient to burst cereals impregnated with oil.

The machine includes a second trough 73 which is located above the portion 68a and which is offset laterally with respect thereto. The trough 73 contains a shaft 74 which is rotated in the direction of clockwise at speed lower than 100t / minute by a motor 75 and the shaft 74 carries stainless steel strands forming a helical brush 76 with a left hand. The trough 73 has in its upper part an opening 77 having a vertical sidewall which extends the circular bottom of the trough which is swept upwards by the brush bristles and split grains form masses 78 located between the plies to bristles of the brush and against the vertical wall of the opening 77 as explained previously.

The circular bottom of the trough 73 and the brush 76 have a diameter greater than the diameter of the circular bottom of the trough 68, 68a and to that of the brush 70.

As seen in Figure 16, the trough 68a of the lower section is closed on top by a circular wall which has a lateral opening 79 which is placed facing a side opening of the bottom of the trough 73 , the two troughs being secured to one another along both longitudinal edges of the common opening 79 by screws, welding or by any other equivalent means.

The opening 79 of the lower trough extends substantially across the upper quadrant of the trough which is located on the side which is swept by the brush 70 amount.

The operation is as follows.

Grain discharged into the trough 68 are uniformly coated with oil and possibly other products as they move in this trough in the direction of the arrow F2. Coated cereals arrive in the heated section 68a where they burst. Their volume increases significantly and their density decreases.

Exploded grains are entrained by the brush 70 toward the opening 79 and under the effect of the increase in volume and pressure due to the bursts, they enter the bottom of the trough 73 where they are swept by the bristle the brush 76 which drive up where they form clusters 78. Thus, exploded cereals are removed as and when they are produced out of the section 68a where they risk being damaged.

With its larger diameter, the brush 76 disposed in the trough 73 is able to absorb the increase in volume due to the expansion of grain. Exploded grains accumulate in the orifice 79 between the two troughs before being taken up by the brush 76 and form a screen which reduces heat losses out of the trough 68a and which avoids an excessive elevation of temperature in the trough 73.

Is shown on the right of Figure 15, an exploded part showing a grid 80 which is arranged in the bottom of the trough 68a at the downstream end thereof and which serves to remove unexploded cereals can be recycled. The upstream and downstream ends of the trough 68a are closed. The upstream end of the trough 73 is closed while the downstream end is open and serves for the evacuation of the products. It is possible to coat the already broken grains during their passage through the trough 73.

It is specified that the single helical brushes shown in Figures 9, 11, 13 and 15 can be replaced by double helical brushes inserted one into the other and staggered by half a pitch as those shown in 7.

17 shows a cross section of an alternative embodiment of a machine according to the invention comprising two spiral brushes 82g and 82d, rotating in opposite directions to each other, disposed in a trough 83. The side walls the trough has, in the lower part, a cylindrical shape that surrounds the spiral brush.

These cylindrical walls extend upwardly above the upper generatrix of the brushes, by two flat walls which are symmetrical with respect to plane MM 'and which converge towards this shot amount. The machine comprises a radiant heat source 84, eg constituted by an infrared transmitter which is located above the intermediate part between the two brushes in which the products to be coated accumulate. These products are continuously subjected to the action of infrared radiation and due to the rotation of products due to the mini-turbine effect, the products subject to radiation are new and successively present all sides to infrared radiation, thereby uniformly dry coating products.

18 shows a cross section of an alternative embodiment of a machine according to the invention comprising a product cooling section by a cold air stream or drying by a hot air stream.

This machine comprises, like the previous two helical brushes 85g, 85d rotating in opposite direction, arranged in a stationary trough 86 having cylindrical walls which surround the outer portion of the helical brushes.

The central part 87 of the bottom of the trough is perforated and communicates with a duct 88 which blows hot or cold air depending on the applications.

The trough comprises air extraction means, for example a suction duct 89 which is placed above the brushes and which is supported by the vertical walls of the trough 86.

The air which arrives through the duct 88 passes through the perforated bottom 87 and then through the products 90 which are concentrated in the central portion between the two brushes and it is taken up by the sheath 89. The intensive mixing of the product 90 enables cooling or a very fast drying them on all sides.

Figures 19 and 20 show a partial top view and a cross section of an alternative embodiment of a machine according to the invention.

Figures 3 and 9 are machinery which comprises two helicoidal brushes rotated in opposite directions from each other and having no opposite direction, so that the two brushes cause the products longitudinally in the same direction.

In the case of Figure 3, the rotational speeds of the two brushes are equal and the traveling speeds too.

In the case of Figure 9, the traveling speeds can be unequal or that the rotational speeds are unequal or that the steps have different lengths.

Figures 19 and 20 show an alternative embodiment of a machine comprising two helical brushes 91d, 91g, placed in one trough 92, wherein the two spiral brushes are always rotated in opposite directions to one another , so that they move upwards in the central portion, but not the two brushes are in the same direction, so that the brushes cause the longitudinally products with translational velocities of reverse direction and uneven.

For example, 91g brush, that rotates anticlockwise, a step to the right, and leads the products with a translation speed represented pa r VA arrow, while the brush 91d, which rotates in the direction of clockwise, also has a right-hand and it causes the translation products with a velocity VB which is the opposite direction to the speed VA, which is significantly lower in absolute value than VA.

Preferably, the speed VA is greater than twice VB.

In the case of the figure, no two brushes are equal and we get the speed difference by rotating the brush 91 d slower than 91g brush. Alternatively, the brush 91d may have the same rotational speed as the brush 91g, but not shorter.

In all cases, the product of the pitch by the speed of rotation of a brush is significantly greater than the product of the pitch by the speed of rotation of the other brush.

With this arrangement, the cores 93 that collect between the two brushes are alternately driven by one or the other of the two brushes, sometimes in one direction and sometimes in the other, so that they follow a path winding comprising loops and they stay longer in the machine. As the speed VA is significantly higher than VB, the average speed of the cores is directed along VA.

A machine according to Figs 19 and 20 allows to obtain a very uniform coating with brushes of reduced length. It also helps to coat cores low rates.