The present invention relates to automatic apparatus for the fast cooking of pasta whether long, such as spaghetti for example, or short. for example macaroni.

Known automatic apparatus for the fast cooking of spaghetti is described in the Italian patent no. 1221239. It provides a cooking unit comprising in cascade a pre-cooking chamber working under pressure, a second cooking chamber working at atmospheric pressure and a cooking finishing chamber always working at atmospheric pressure.

The second cooking chamber in turn, so as to eliminate the steam which is produced therein during expansion of the water coming from the pre-cooking chamber, is formed as a cyclone separator which conveys the steam towards a heat regenerator.

One of more important disadvantages suffered by traditional automatic apparatus for the fast cooking of spaghetti is represented by the high damaging risk for the product to be fed along the cooking path.

During the passage from the first to the second cooking chamber the highly accelerated product could impact and break against the inner walls of the

second cooking chamber or, after a short jump, against the steam collector inside to the second cooking chamber.

The main object of the present invention is thus that of providing automatic apparatus for the fast cooking of pasta which preserves an entire product along the cooking path.

Another object of the present invention is that of providing automatic apparatus for the fast cooking of pasta which is simple and inexpensive, and capable of economising energy consumption.

Yet another object of the present invention is that of providing automatic apparatus for the fast cooking of pasta, suitable for the cooking of long pasta and also of short pasta.

The main object is achieved by automatic apparatus for the fast cooking of pasta comprising : -a cooking unit, in turn comprising : a pre-cooking chamber fed by cooking water pressurised at a value higher than saturated steam pressure at the maximum temperature reached by the cooking water and, in cascade, a second cooking chamber operating substantially at atmospheric pressure and provided with an outlet for steam recovery, and a cooking finishing chamber operating at atmospheric pressure ; characterised in that said second cooking chamber comprises a lower half- portion wherein the pasta coming from the first chamber is discharged and an upper half-portion acting as steam separator and separated from the lower half- portion by a partition provided with a stem collector directed towards the interior of the upper half-portion of the second cooking chamber.

The inner wall of the lower half-portion of the second cooking chamber is further tangentially joined to the conduit feeding the pasta to the second cooking chamber.

In this way the most part of the pasta coming from the first chamber is slidingly guided in a helicoidal descending path along the inner wall of the lower half- portion of the second cooking chamber. The steam collector is far away from each possible alternative path for the pasta which therefore never finds during its travel any obstacle or impediment close to it, in particular during entering the second cooking chamber wherein it has the greatest kinetic energy.

These and other advantages of the present invention will be made clearer on reading one of its preferred embodiments which refers to the following accompanying drawings, in which: Fig. 1 illustrates an overall diagram of a preferred embodiment of the apparatus of the present invention ; Fig. 2 illustrates an enlarged detail of the pre-cooking chamber for spaghetti of the embodiment of Fig. 1 ; Fig. 3 illustrates a side view of an enlarged detail of the second cooking chamber with the steam separator of the embodiment of Fig. 1 ; Fig. 4 illustrates an enlarged sectioned view of the cooking chamber with the connection to the cooking chamber taken along line 4-4 of Fig. 1 ; and Fig. 5 illustrates an enlarged sectioned side view of the means of loading the spaghetti of the embodiment of Fig. 1.

In Fig. 1 the automatic apparatus for the fast cooking of pasta is formed by a single pressurisation unit 1 connected via a water circuit to two identical cooking units 3.

The pressurisation unit 1 is formed by a pressuriser plenum 5 filled internally by a predefined mass of air and by a volume of water which varies according to the pressure set.

The plenum 5 is fitted with an inlet mouth 13 for the water coming from an external water supply line 7, in turn comprising a purifier 8, a pump 9 and a non-return valve 11, intended to top up the water and the steam discharged from the apparatus, an outlet mouth 15, and a pressure switch which, as we will see, enables the pump 9 to inject water into the plenum 5 when the pressure in the plenum 5 drops below a predefined threshold.

A heater assembly 17 also forms part of the pressuriser unit 1, fed by the mouth 15 of the plenum 5 and formed by a first tank 19 for approximate regulation of the temperature of the pressurised water in series with a second tank 21 for precise regulation of the temperature of the pressurised water. The temperature is regulated by using in each tank 19 and 21 an electric heater, for example a resistor, or any other equivalent means, piloted by a thermostat.

Each cooking unit 3 defines a cooking path for long pasta, typically spaghetti, or respectively a cooking path for short pasta, typically macaroni. The cooking path extends through three chamber placed in cascade : a pre-cooking chamber 29 or respectively 29'operating under pressure, a second cooking chamber 23 and a cooking finishing chamber 27.

The pre-cooking chambers 29 and 29'are fitted above with a pneumatic valve for loading the portion of pasta to be cooked, precisely a pneumatic ball valve 31 for the chamber 29 for pre-cooking of the spaghetti and a pneumatic butterfly valve 33 for the chamber 29'for pre-cooking of the macaroni, with a pneumatic ball valve 35,35'below for feeding the cooking water, and a pneumatic valve for discharging the pre-cooked portion to the second cooking chamber 23. The valve for discharging the portion of pre-cooked pasta of the

chamber 29'for pre-cooking the macaroni is again a butterfly valve 37 located on the base, while the discharge valve of the chamber 29 for pre-cooking spaghetti is again a ball valve 39, diametrically aligned with the valve for feeding the cooking water 35 at the base.

The discharge valves 37 and 39 of the pre-cooking chambers 29'and 29 feed a connection conduit 41'and 41 having a tangential coupling 42 to the second cooking chamber 23, with vertically aligned outflow sections 43'and 43.

The base of the chamber 29 for pre-cooking the spaghetti is also formed by a wedge 77 whose lateral conical surface is placed between the valve 35 for feeding the cooking water and the discharge valve 39.

The wedge 77 opens the bundle of spaghetti before feeding the cooking water, and subsequently guides the head of the spaghetti towards the mouth 81 of the conduit 41 of the discharge valve 39, in turn gradually joined to the internal lateral wall 83 of the pre-cooking chamber 29.

By optimising the angular opening and height of the wedge 77, together with the radius of curvature of the coupling between the pre-cooking chamber 29 and the conduit 41, all the spaghetti can slide gently towards the second cooking chamber 23.

The second cooking chamber 23 communicates with the cooking finishing chamber 27 via a pneumatic guillotine valve 45, while the base of the cooking finishing chamber 27 is formed by a pneumatic guillotine valve 47 and peripherally has a grid wherefrom, before the opening of the guillotine valve 47, the cooking water can be extracted via a pump 49 in such a way as to present on the plate 51 a portion drained to the correct degree of moisture.

The second cooking chamber 23 comprises an upper half-portion 25 hermetically associated by means of fixing screws 53 to the flanged upper edge of a lower half-portion 24 of the second cooking chamber 23.

The upper 25 and lower 24 half-portions are separated by a partition 55 from the center of which a steam collector 59 extends toward the interior of the upper half-portion 25 of the second cooking chamber 23.

On the discharging mouth of the steam collector 59 a filter 57 is applied having calibrated holes for selective passage of steam but not of pasta. The filter results from superimposing two disks made of perforated sheet wherein the diameter and pitch of the inner sheet are greater than outer sheet.

In an alternative way the filter could be placed at the mouth of the steam collector 59.

The upper half-portion 25 of the second cooking chamber 23 finally has two mouths 61 for release of the steam onto a steam recovery line 63.

The pressurised and over-heated water, from the tank 21, is diverted onto water supply lines 65 and 65'connected to the valve 35 and 35'for feeding the cooking water of each pre-cooking chamber 29 and 29'.

Advantageously, this invention provides a single assembly 67 for preheating the cooking water formed by a tank 69 connected to the discharge steam line 63, wherein a heat exchanger is inserted for each cooking unit 3, formed by a coil for exchange in counter-current between the water of the line 71 for discharge from the cooking finishing chamber 27 and the water of a corresponding line of diversion 73 from the pressuriser 5.

The lines of diversion 73 from the plenum 5, the same number as the lines 71 of the discharge water from the cooking finishing chambers 27, flow back in a single point before feeding into the tank 19 of the heater assembly 17.

Such a configuration of the preheater assembly 67 allows the heat energy still contained in the discharge steam and water to be recycled in full as it creates transmission of thermal energy from the steam contained in the tank 69 to the discharge water lines 71, and simultaneously from the lines 71 of the discharge water to the lines 73 of the pressurised water to be sent to the heating assembly 17 and from there to the cooking units 3.

On the base of the tank 69 a discharge mouth 75 is provided for expelling the water which flows from the lines 71 and the steam which has condensed in the tank 69 itself.

The cooking units also comprise, above the pre-cooking chambers 29, a loader suitable for the long or short pasta type to be loaded.

If for short pasta, the loader comprises a container 85 for storing the pasta, with a lower end for transfer of the pasta to a vibrating longitudinal channel 87 which in turn feeds a proportioning drum 89 situated vertically aligned above the loading valve 33 and formed by two doors 91 enabled to open when the portion of pasta to be loaded reaches a predefined weight.

If for short pasta, the loader comprises a container 93 for storing spaghetti, a selector 95 of the portion to be leaded, and a hopper 97, rotating between a horizontal position for receiving the spaghetti from the selector 95 and a vertical position for discharging the spaghetti into the pre-cooking chamber 29 via the loading valve 31.

The container 93 is formed by a front wall 99 and a rear wall 101, slanted and converging, whereon the spaghetti, arranged horizontally, slide slowly.

The front wall 99 also has an intermediate bend 103 which ensures that the spaghetti are maintained in an orderly arrangement when falling towards the selector 95.

The selector 95 is formed by a pair of interception laminae 96 driven by pneumatic actuators, capable of penetrating transversely the lower neck 105 of the container 93 to define with the side walls of the container 93 itself the portion of spaghetti to be sent to the hopper 97.

The sliding of each lamina 96 is guided by a pair of aligned horizontal slots 107 formed on the front wall 99 and rear wall 101 of the container 93, and develops between a position of full insertion and a position of full extraction from the container 93.

Advantageously, in the position of full insertion, the head end 109 of the laminae 96 projects for a certain length from the corresponding slot 107 of the front wall 99 of the container. In this way, starting from the upper lamina in a position of full extraction and from the lower lamina in a position of full insertion, the upper lamina is gradually inserted until its head aligns with the corresponding slot, while simultaneously the lower lamina is gradually extracted until its head also reaches the corresponding head slot, and this movement assists the spaghetti present in the volume, which can be enclosed between the two laminae, in settling and reaching the correct horizontal position. In this way the risk is finally eliminated of some spaghetti, arranged with a non-horizontal slant, from being accidentally cut by the upper lamina.

The overall operation of the machine is the following :

The pressuriser 5 and the heater assembly 17 are calibrated in such a way as to supply cooking water to the cooking units at 12 atm and 170°C, a value well above the two-phase equilibrium point between liquid and steam even after partial expansion in the pre-cooking chambers 29 and 29'. This pressure value ensures qualitative satisfactory cooking in the pre-cooking chambers 29 and 29', whose walls are thermostat-controlled at 150°C, and reduces by up to 25% the permanence time currently necessary for the pasta in each of the chambers of the cooking unit.

Reaching of these values for the pressure and the temperature of the cooking water is enabled thanks to the configuration of the pre-cooking and second cooking chambers and of the connections between them which form a path of guided sliding for the pasta, preventing it, albeit moving at high speed from the pressurised pre-cooking chamber to the second cooking chamber which is at a substantially atmospheric pressure, from undergoing damaging jumps or impact.

In particular the path of guided sliding is formed thanks to the tangential coupling of the connection conduit 41 and 41'to the second cooking chamber 23, thanks to the arrangement of the steam collector 59 inside the half-portion 25 of the second cooking chamber 23, and thanks to the vertical alignment of the sections 43 and 43'for feeding the pasta to the second cooking chamber 23 which do not interfere one with the other.

After having loaded the type of pasta chosen by the user into the relative pre- cooking chamber, the apparatus re-closes the pasta loading valve 31 or 33 and opens the water feed valve 35 or 35', with the discharge valve 37 or 39 which remains closed.

At this point the cooking water, from the outlet mouth 15 of the pressuriser 5, traverses the preheater assembly 67, whose high efficiency is measured by the

temperature of the discharge water from the tank 69 which, with the present embodiment, is lowered to 35°C, enters the heater assembly 17, into the line 65 or 65'for connection to the pre-cooking chamber 29 or 29', and finally reaches the pre-cooking chamber 29 or 29'where it expands partially, compressing the air contained therein until the pressure inside the pre-cooking chamber 29 or 29'is equal to the external pressure.

The pressure switch of the pressuriser 5, when the pressure inside it drops below a preset value but in any case well above the saturated steam pressure at the maximum temperature reached by the cooking water, enables the topping-up pump 9 for feeding of water from an external water supply source.

A few moments prior to the end of cooking in the pre-cooking chamber 29 or 29', the water feed valve 35 or 35'is closed and, at the subsequent opening of the discharge valve 37 or 39, the cushion of compressed air above the cooking water expands, pushing the pre-cooked pasta at high speed towards the second cooking chamber 23.

The pasta continues cooking for a time approximately equal to the pre-cooking time, while the steam produced by the expansion rises towards the collector 59 and is sent through the mouths 61 and the lines 63 to the tank 69 for recovery of the heat of the preheater assembly 67. In this phase the filter 57 of the collector 59 prevents part of the pasta from entering the separator 25.

At the end of second cooking the pasta is conveyed via opening of the guillotine valve 45 to the finishing chamber 27 where it remains for a time approximately equal to the time of permanence in each of the previous chambers.

Before the opening of the guillotine valve 47 which takes the pasta directly onto the plate 51, the pump 49 aspires the excess water through a grid situated

peripheraily at the base of the chamber 27 and conveys it towards the preheater assembly 17.

Naturally it is possible, by the same methods described in the present embodiment, to insert in the apparatus, according to the intended purpose and consumption of pasta foreseen, a different number of cooking units, and a number of pre-cooking chambers for each cooking unit equal to the varieties of pasta required.

The apparatus described, loading a portion of 100 grams of spaghetti with diameter of 1.7 mm and a litre of cooking water in the following working conditions : cooking water sent to the pre-cooking chamber at 12 atm and 170°C, walls of the pre-cooking chamber thermostat-controlled at 150°C, walls of the second cooking and cooking finishing chamber thermostat-controlled respectively at 120°C and 100°C, water discharging from the tank of the preheater assembly at 35°C, is capable, for each cooking unit, of completing the first cycle of cooking in approximately 45 seconds and of preparing subsequent dishes in the case of continuous functioning at intervals of 15 seconds one from the other, enhancing the taste and smell characteristics and conserving the nutritional properties of the product.