Patent Description:
In the context of processing of liquid or semi-liquid food products, a need that users feel particularly strongly is that to be able to thermally treat the liquid or semi-liquid food products, specifically to subject them to a preventive pasteurization (heating) treatment in a particularly simple and efficient manner.

One drawback of certain kinds of existing pasteurizing machines is connected to the fact that it is particularly difficult to uniformly regulate the temperature of the product being processed: in many cases, this leads to localized burning or overheating of the product, particularly in the zones near the heated walls of the container, which may significantly modify the quality and organoleptic properties of the product being processed.

Document <CIT> discloses a device for the preparation and dispensing of soft ice cream, sherbet or flavoured ice, which has two spatially separated and distinct chambers connected by means of elongated supply tubes, one chamber serving as a storage container in which refrigerating, heating, and sterilizing functions are carried out, and the other serving as a freezing and dispensing container. Document <CIT> discloses a pasteurizing group of liquid food mixtures comprising at least one- pasteurizing device, at least one supply duct and at least one outlet duct for said liquid food mixtures associated with said at least one pasteurizing device, temperature control means of said liquid food mixtures inside and/or leaving said at least one pasteurizing device and selective blocking means of said at least one outlet duct.

Document <CIT> shows a machine for making and dispensing liquid, semi-liquid and/or semi-solid food products and which comprises at least a cylinder for containing and processing basic products, means for heating and cooling the cylinder wrapped around at least part of the cylinder and a mixer unit positioned inside the cylinder which is able to mix the basic products during their processing; the machine also comprises a supply duct for supplying the products into the cylinder, a dispensing duct for withdrawing the food products from the cylinder and means for recirculating the products contained in the containment and processing cylinder which are able to withdraw the products from the cylinder through the dispensing duct and to return them into the cylinder through the supply duct.

Document <CIT> shows machine for making and dispensing chocolate, comprising: at least one chocolate processing container; a chocolate dispenser tap connected to the processing container for allowing chocolate dispensing; at least a first mixer associated with the container for mixing the chocolate being processed; thermal treatment means associated with said at least one processing container and designed to heat and/or cool the walls of said processing container; an operating and control unit.

Document <CIT> shows a machine for making and dispensing semiliquid and/or semisolid food products comprising a working unit equipped with a cylinder for processing a mixture of a basic product and air, a heat exchange fluid flow chamber located around the cylinder, a dispensing tap and means for treating and feeding the heat exchange fluid to the flow chamber, is equipped with a flexible container for containing the basic product; a peristaltic pump transfers the basic product from the container to the processing cylinder through a supply duct along which there is a first pressure sensor for the pressure of the mixture fed into the cylinder.

Document <CIT> shows a machine for mixing and cooling ice cream and equipped with: a processing container defining a processing chamber and provided with a stirrer rotating inside the processing chamber; and a thermal treatment system, configured to be activated, selectively and alternatively, in heating or cooling mode, for heating and cooling the processing chamber, respectively.

Document <CIT> discloses a machine for making and dispensing cold or iced products comprises at least: an element for containing the product to be dispensed and equipped with a mouth for dispensing the food product; a dispenser located at the mouth for dispensing the food product and able to be turned on or off to allow the food product to be dispensed; a thermal treatment cylinder; a stirrer, coaxial with the thermal treatment cylinder and adapted to rotate about a respective axis of rotation; a refrigeration system in which a refrigerant fluid circulates and comprising an evaporator associated with the thermal treatment cylinder, a condenser, a pressure reducing element and a compressor.

Document <CIT> discloses an ice-cream making machine adopting reducer transmission, comprising a machine case, a compressor, a condenser, an evaporator, a stirring cylinder, a motor, a reducer, a feed basin, a discharge valve and a control panel are disposed on the machine case. The machine case is a rectangular box formed by sequential connection of a front panel, a back panel, a top panel, a bottom panel, a left panel and a right panel. The compressor and the condenser are disposed on the bottom panel. The compressor, the condenser and the evaporator are sequentially connected.

This invention therefore has for an aim to meet the above-mentioned need, in particular that of making available a machine and a method which, thanks to its features, allows the products being processed to be thermally treated in a particularly simple and efficient manner.

A further aim of this invention is therefore to provide a machine and a method which, thanks to its features, allows the product being processed to be heated uniformly and prevents localized heating of the product.

The technical features of the disclosure, with reference to the above aims, are clearly described in the annexed claims and its advantages are more apparent from the detailed description which follows, with reference to the accompanying drawings which illustrate an example, non-limiting embodiment and in which:.

With reference to the accompanying drawings, the numeral <NUM> denotes a machine of the invention for thermally treating (more specifically, pasteurizing) liquid or semi-liquid food products.

The machine <NUM> is adapted to thermally treat ice cream products (artisan gelato or soft ice cream) or patisserie products or soups and the like.

The machine <NUM> for pasteurizing liquid or semi-liquid food products comprises:.

According to another aspect, the stirrer <NUM> is externally helically shaped and extends between a first, inlet end <NUM> and a second, outlet end <NUM>, so that as it rotates, the liquid or semi-liquid product is made to advance between the first, inlet end <NUM> and the second, outlet end <NUM>.

As illustrated in the accompanying drawings, the machine <NUM> comprises a drive unit <NUM> connected to the stirrer <NUM>, for driving it in rotation.

Preferably, the drive unit <NUM> is connected to a processing and control unit <NUM>.

According to another aspect, the thermal system <NUM> comprises a heat exchanger <NUM> associated with the first processing container <NUM> (mentioned above), a further heat exchanger <NUM>, a compressor <NUM>, and a pressure reducing unit <NUM>.

It should be noticed that the heat exchanger <NUM>, the further heat exchanger <NUM>, the compressor <NUM>, and the pressure reducing unit <NUM> define a circuit containing a heat exchanger fluid.

In other words, the thermal system <NUM> is a thermodynamic system (configured to operate according to a thermodynamic cycle using a heat exchanger fluid).

According to another aspect, the thermal system <NUM> may comprise a sensor <NUM> adapted to detect the pressure or temperature of the heat exchanger fluid at a point in the circuit.

According to yet another aspect, the machine <NUM> comprises a dispenser <NUM>, which is connected to the first processing container <NUM> for processing a liquid or semi-liquid base product, and which allows the product to be extracted from the container <NUM>.

The heat exchanger <NUM> defines a condenser of the thermodynamic circuit.

It should be noted that other configurations of the thermal system <NUM> are also imaginable.

For example, the thermal system <NUM> might be of the hot gas type, where the gas is recirculated only between the compressor and the exchanger <NUM>, transferring heat to the exchanger <NUM>.

According to yet another aspect, the machine <NUM> is provided with an exchanger which is adapted to cool the product inside the first processing container <NUM>.

It should be noted that the exchanger might be the heat exchanger <NUM> mentioned above (or a different exchanger): in this case, the thermal system <NUM> is preferably switchable between two configurations: a first configuration in which the exchanger <NUM> heats and a second configuration in which the exchanger <NUM> cools.

A thermal system <NUM> adapted to be switched between two configurations, so that the heat exchanger <NUM> can be used for heating or cooling, is described in <CIT>.

Advantageously, according to this aspect, the first, processing container <NUM> can be heated or cooled.

It should be noted that according to this aspect, the machine <NUM> is preferably provided with user-activable means (controls) for selecting the configuration to set the exchanger <NUM> of the thermal system <NUM> to the cooling or heating configuration.

Thus, advantageously, the machine <NUM> can perform cooling or heating cycles on the product, depending on specific processing requirements.

The dispenser <NUM> preferably comprises a user-activable lever for allowing liquid or semi-liquid base product to be dispensed.

According to another aspect, the second, feed container <NUM> is an open-top tub.

According to another aspect, the second, feed container <NUM> for feeding the liquid or semi-liquid base product is a cylinder.

According to yet another aspect, the machine <NUM> comprises a drive and control unit <NUM> connected to the thermal system <NUM> and configured to control the thermal system <NUM> in order to heat the walls of the first, processing container <NUM> to a temperature between <NUM> and <NUM> (preferably to a temperature between <NUM> and <NUM> and, still more preferably to a temperature between <NUM> and <NUM>).

According to another aspect, the stirrer <NUM> comprises a first portion 4A which is externally helically shaped and a second portion 4B which has at least one radial blade <NUM>.

It should be noted that the stirrer is illustrated schematically in <FIG>: the stirrer <NUM> is shown in more detail in <FIG>.

It should be noted that, in conjunction with the inside wall of the first container <NUM>, the portion 4A which is externally helically shaped defines a chamber along which the product is made to advance by effect of the rotation of the stirrer <NUM> (and in which the product is subjected to a thermal treatment, preferably heating).

The second portion 4B is disposed at the first, inlet end <NUM> and the first portion 4A is disposed at the second, outlet end <NUM>.

The main function of the second portion 4B is that of stirring the product.

The first portion 4A, on the other hand, thanks to its structure, has the function of pushing the product along the direction of extension of the first container <NUM>.

According to a further embodiment, illustrated schematically in <FIG>, the machine <NUM> comprises:.

The second stirrer <NUM> has the same features as those described with reference to the stirrer <NUM>.

According to another aspect, the second exchanger <NUM> associated with the walls of the third, processing container <NUM> is configured to cool the base product inside the third, processing container <NUM>. Thus, the third, processing container <NUM> cools the product.

Preferably, the third, processing container <NUM> is a cylinder.

According to another aspect, the first container <NUM> is connected to the third container <NUM> so that the thermally treated product coming out of the first container <NUM> is conveyed directly to the third container <NUM>.

According to this aspect, the machine <NUM> preferably comprises a pump <NUM> (illustrated schematically in <FIG>) to convey the product from the first container <NUM> to the third container <NUM>.

According to yet another aspect, the second, feed container <NUM> is connectable to the first, thermal treatment container <NUM> and to the third, thermal treatment container <NUM>.

Preferably, the machine <NUM> comprises a valve assembly <NUM> configured to allow placing the second, feed container <NUM> in fluid communication (to feed product) with the first, thermal treatment container <NUM> and/or with the third, thermal treatment container <NUM>.

According to an aspect, the valve assembly <NUM> may comprise a pump, which can be enabled and disabled to convey product from the second, feed container <NUM> to the first, thermal treatment container <NUM> and/or to the third, thermal treatment container <NUM>.

As illustrated in the embodiment of <FIG>, the machine <NUM> comprises a drive unit <NUM>, connected to the stirrer <NUM> to drive it in rotation.

Preferably, the drive unit <NUM> is connected to the processing and control unit <NUM>.

According to another aspect, the machine illustrated in <FIG> comprises a second dispenser <NUM>, adapted to allow dispensing the liquid or semi-liquid product from the third container <NUM>.

<FIG> illustrates an embodiment provided with a recirculation duct <NUM> between the inlet end <NUM> and the outlet end <NUM> of the container <NUM>. It may be observed that the product advancing by the effect of the rotation of the stirrer <NUM> can thus be returned to the inlet of the container <NUM>: that way, heating can be performed more progressively because the product traverses the container <NUM> several times.

<FIG> illustrates an embodiment provided with a recirculation duct <NUM> between the outlet end <NUM> and the container <NUM>.

It may be observed that the product advancing by the effect of the rotation of the stirrer <NUM> can thus be returned to the inlet of the container <NUM>: that way, heating can be performed more progressively because the product traverses the container <NUM> several times.

It should be noted that according to another aspect, the exchanger <NUM> associated with the walls of the first processing container <NUM> and configured to release heat to the first thermal treatment container <NUM> may also cool the first container <NUM> (as described above).

According to this aspect, the drive and control unit <NUM> is configured to control switching of the thermal system between the configuration for heating and the configuration for cooling the container <NUM>.

According to another aspect, the thermal system comprises a second exchanger (not illustrated and different from the exchanger <NUM>) adapted to cool the first processing container <NUM>.

It should be noted that with reference to the machines <NUM> illustrated in <FIG> and <FIG>, the machine <NUM> might also be provided with an exchanger adapted to cool the product in the third, processing container <NUM>.

It should be noted that the exchanger might be the aforementioned heat exchanger <NUM>: in this case, the thermal system <NUM> is preferably switchable between two configurations: a first configuration in which the exchanger <NUM> heats and a second configuration in which the exchanger <NUM> cools.

A thermal system <NUM> adapted to be switched between two configurations, so that the heat exchanger <NUM> can be used for heating or cooling, is described in <CIT>. Advantageously, according to this aspect, the third, processing container <NUM> can be heated or cooled.

Also defined according to the invention is a method for pasteurizing (heating) liquid or semi-liquid food products in a machine according to any of the aspects described above, comprising the following steps:.

According to an aspect, the method comprises a step of causing the product to flow out of the outlet end <NUM> of the stirrer <NUM>.

According to yet another aspect, the step of heating the walls of the first, processing container <NUM> to a temperature between <NUM>° and <NUM> comprises a step of heating the walls of the first, processing container <NUM> to a temperature between <NUM>° and <NUM> (preferably between <NUM>° and <NUM>).

It should be noted that one advantage of this invention is that the product subjected to pasteurization is moved substantially continuously inside the first container <NUM>, which means that the product is heated uniformly and progressively.

Furthermore, the degree of heating - that is, the final temperature reached - may be controlled in a particularly simple manner by varying the rotation speed of the stirrer <NUM>: in effect, the slower the rotation speed of the stirrer <NUM>, the longer the time the product is subjected to heating. It is thus possible (at least within a certain interval) to vary the pasteurization temperature - that is, the final temperature reached by the product - by simply adjusting the rotation speed of the stirrer, without necessarily having to vary the thermal power delivered through the exchanger <NUM>.

Claim 1:
A machine (<NUM>) for pasteurizing liquid or semi-liquid food products, comprising:
- a first cylindrical container (<NUM>) for the thermal treatment of a liquid or semi-liquid base product;
- a second container (<NUM>) for feeding the liquid or semi-liquid base product, connected to the first, thermal treatment container (<NUM>), for feeding the liquid or semi-liquid base product;
- a stirrer (<NUM>) for mixing the product in the first, processing container (<NUM>) and mounted inside the first, thermal treatment container (<NUM>), the stirrer (<NUM>) extending between a first, inlet end and a second, outlet end, so that as it rotates, the liquid or semi-liquid product is made to advance between the first, inlet end (<NUM>) and the second, outlet end (<NUM>);
- a thermal system (<NUM>) comprising an exchanger (<NUM>) associated with the walls of the first, processing container (<NUM>) and configured to release heat to the first, thermal treatment container (<NUM>), the machine being characterized in that the stirrer (<NUM>) comprises a first portion (4A) which is externally helically shaped and a second portion (4B) having at least one radial blade (<NUM>), the second portion (4B) being disposed at the first, inlet end and the first portion (4A) being disposed at the second, outlet end.