阅读说明：本技术 对要处理的谷物颗粒或水果种子进行均匀烘烤的装置 (Device for uniformly roasting cereal grains or fruit seeds to be treated ) 是由 J-L·贝诺伊特 于 2018-09-26 设计创作，主要内容包括：本发明涉及一种用于颗粒、特别是诸如大米的谷物颗粒的预处理的装置,该装置包括用于烘烤颗粒的腔室(1)、位于腔室(1)内并被布置成允许蒸汽通过并防止谷物与腔室(1)直接接触的微孔篮(2),该装置还包括连接到所述腔室(1)的真空源和蒸汽源,其特征在于,该装置包括敞开到所述腔室(1)的壁与篮(2)的壁之间形成的空间(3)中的至少一个蒸汽扩散管道、以及位于所述篮(2)中的至少一个微孔管道,在所述篮(2)的内表面与所述至少一个微孔管道的外表面之间的横向平面中测量的距离小于或等于600毫米。(The invention relates to a device for the pre-treatment of particles, in particular cereal particles such as rice, comprising a chamber (1) for roasting the particles, a microporous basket (2) located inside the chamber (1) and arranged to allow the passage of steam and to prevent direct contact of the cereal with the chamber (1), the device further comprising a vacuum source and a steam source connected to said chamber (1), characterized in that it comprises at least one steam diffusion duct opening into the space (3) formed between the wall of said chamber (1) and the wall of the basket (2), and at least one microporous duct located in said basket (2), the distance measured in a transverse plane between the inner surface of said basket (2) and the outer surface of said at least one microporous duct being less than or equal to 600 mm.)

1. An apparatus for pre-treating particles, in particular cereal particles such as rice, the apparatus comprising: a chamber (1) having an opening that can be hermetically sealed for supplying untreated rice; a microporous basket (2) located inside the chamber (1) and arranged to allow the passage of steam and to prevent direct contact between the grains and the chamber (1), the apparatus further comprising a vacuum source and a steam source connected to the chamber (1), characterized in that it comprises at least one steam diffusion duct leading to the inside of the chamber (1) in the space (3) formed between the walls of the chamber (1) and the microporous basket (2), and at least one microporous duct located in the microporous basket (2), the distance measured in a transverse plane between the inner surface of the microporous basket (2) and the outer surface of the at least one microporous duct being less than or equal to 600 mm.

2. The apparatus according to the preceding claim, characterized in that the diffusion conduit comprises a portion extending over the entire height or a partial height of the microporous conduit.

3. The apparatus according to the preceding claim, wherein the microporous tube and the microporous basket (2) are arranged such that the distance measured in a transverse plane between the inner surface of the microporous basket (2) and the outer surface of the at least one microporous tube is less than or equal to 450 mm.

4. The apparatus according to any of the preceding claims, characterized in that the microporous basket (2) is cylindrical and the microporous piping is coaxial with respect to the microporous basket (2).

5. The apparatus according to the preceding claim, characterized in that the microporous basket (2) has a cylindrical unloading compartment in the lower part and the microporous piping has a microporous front end located at a distance of less than or equal to 350 mm from the wall of the cylindrical compartment.

6. The apparatus according to the preceding claim, wherein the microporous front end is located at a distance of less than or equal to 250 mm from the wall of the cylindrical compartment.

7. The apparatus according to any one of the preceding claims, characterized in that the chamber (1) has in the upper part a movable loading port, and a double lip seal ensuring pressure and vacuum sealing.

8. The apparatus of any one of the preceding claims, wherein the microporous conduit forms a vapor diffusion conduit.

Technical Field

The present invention relates to the field of pre-treatment by precooking of grains obtained from cereals or fruits. By extension, the term "particle" includes the term "seed".

The invention relates more particularly to an apparatus for pre-treating particles, in particular cereal particles such as rice, comprising: a chamber having an opening capable of being hermetically sealed for supplying untreated particles; a microporous basket located inside the chamber and arranged to allow passage of steam, the apparatus further comprising a vacuum source and a steam source connected to the chamber.

The apparatus is intended (particularly, but not exclusively) for processing rice and cashew nuts.

Background

Blanching is a commonly used operation in the rice industry. It involves the use of steam treatment to precook raw rice grains ("rice") to gelatinize the starch. Gelatinization of starch imparts a new property to granules that resist overcooking and do not stick (do not stick to rice) (the ability of granules to remain hard when overcooked).

Conventional blanching techniques involve subjecting rice to pressurized steam after the rice has been subjected to a soaking operation at 60 ℃ for 3 to 4 hours in advance or overnight in cold water. However, these techniques have the disadvantage of not being entirely satisfactory from a nutritional point of view, since the steeping and heating of rice results in a partial loss of nutritional quality and of vitamin and mineral salts. Furthermore, due to the gelatinization of starch, precooking generally results in a slight increase in cooking time, which forms a sort of shell around the inner core of the granule on the surface of the rice kernels.

To overcome these drawbacks, application EP3041369 proposes an apparatus which makes it possible to precook untreated rice without having to resume the previous soaking operation. The apparatus comprises an autoclave connected to a source of steam and means for controlling a treatment cycle comprising injecting steam pressure into the autoclave at a temperature of 140 ℃ to 190 ℃ at a pressure of 6 bar to 10 bar, maintaining the pressure for a period of 10 seconds to 90 seconds, and then opening a steam vent valve. Directly pre-cooking rice without soaking in advance.

The disintegration of the rice grains is adapted to promote the impregnation of the steam and the cooking time is reduced, thanks to the absence of soaking and controlled variation of the pressure and temperature conditions of the steam injected inside the autoclave, and to the instantaneous pressure release.

However, the object of the present invention is to improve the device of the above application by proposing a device that: the device allows for the uniform treatment of the pellets to be precooked and for uniform gelatinization of rice in the case of pretreatment thereof, while preserving the nutritional quality of the pellets.

Another object of the invention is to propose a device which makes it possible to reduce the water required for precooking by 90%.

Disclosure of Invention

To this end, and according to a first aspect, the invention proposes an apparatus for pre-treating particles, in particular cereal particles such as rice, said apparatus comprising: a chamber having an opening capable of being hermetically sealed for supplying untreated rice; a microporous basket located inside the chamber and arranged to allow the passage of steam and to prevent direct contact between the grains and the chamber, the apparatus further comprising a vacuum source and a steam source connected to the chamber, characterized in that it comprises at least one steam diffusion duct leading to the inside of the chamber in the space formed between the wall of the chamber and the wall of the microporous basket, and at least one microporous duct located in the microporous basket, the distance measured in a transverse plane between the inner surface of the microporous basket and the outer surface of the at least one microporous duct being less than or equal to 600 mm.

Advantageously, the diffusion conduit comprises a portion extending over all or part of the height of the microporous conduit.

Advantageously, the microporous tube and the microporous basket are arranged such that the distance measured in a transverse plane between the inner surface of the microporous basket and the outer surface of the at least one microporous tube is less than or equal to 450 millimeters.

Advantageously, the microporous basket is cylindrical and the microporous conduit is coaxial with respect to the microporous basket.

Advantageously, the microporous basket has a cylindrical unloading compartment in the lower part and the microporous pipe has a microporous front end located at a distance less than or equal to 350 mm (preferably less than or equal to 250 mm) from the wall of the cylindrical compartment.

Advantageously, the chamber has a movable loading port in the upper part and a double lip seal ensuring pressure and vacuum sealing.

Advantageously, the microporous tube forms a vapour diffusion tube.

Drawings

Further objects and advantages of the present invention will become apparent from the following description, given with reference to the sole drawing, which shows a schematic cross-section of a device according to the present invention for treating grains, in particular rice, by precooking.

Detailed Description

The sole figure shows an apparatus for pre-treating (precooking) grains, in particular rice. The pre-cooking apparatus is part of a broader apparatus like the one described in the application EP 3041369. Only the part of the device for precooking rice that is the subject of the present invention is described below.

Thus, the apparatus comprises: a pre-cooking chamber for untreated rice, inside which a microporous basket 2 for receiving rice to be pre-cooked is placed; a vacuum source and a steam source connected to the chamber (these sources are not shown).

The chamber 1 has at least one opening that can be hermetically sealed by a cover (not shown) to allow introduction and discharge of rice. In the embodiment shown, the chamber has two openings, one opening being provided in the upper part for introducing the rice to be precooked and pouring the rice to be precooked into the basket; another opening is provided at the lower portion for discharging the rice after the rice is pre-cooked. The opening may be hermetically sealed so that the chamber may be pressurized. The chamber also has an opening in the lower part allowing the evacuation of the condensed water during and after the treatment. These openings are advantageously controlled by solenoid valves.

The chamber 1 is also connected to three steam supply ducts 30, 31, 50. The chamber is also connected to a vacuum tank, which is itself connected to a vacuum pump, for evacuating the chamber 1.

The basket 2 (advantageously cylindrical) is sized with respect to the chamber 1 so as to leave a space 3 between the inner wall 10 of the chamber 1 and the outer wall 20 of the basket 2, to prevent any direct contact between the rice to be precooked and the walls of the chamber 1. The basket has microporous walls to allow diffusion of the steam under pressure inside the chamber 1. The upper portion of the basket 2 is opened to allow the rice to be supplied thereto; and the lower portion of the basket is opened to allow the rice to be discharged. The opening of the lower part of the basket is advantageously closed by a valve to retain the rice during the treatment and to discharge it at the end of the treatment.

The chamber 1 comprises a first vapor diffusion duct 4 and a second vapor diffusion duct 5, the first vapor diffusion duct 4 and the second vapor diffusion duct 5 being arranged in the space 3 formed between the wall of said chamber 1 and the wall of the microporous basket 2 and extending along the wall of the chamber 1.

The chamber 1 further comprises a microporous tube 6 located in said microporous basket 2 and extending over its height. In particular, the tube 6 is positioned at a distance, measured in a transverse plane between the inner wall 21 of the microporous basket 2 and the outer wall 60 of the second conduit, which is less than or equal to 600 mm, and preferably less than or equal to 450 mm. Said tubes 6 constitute a third steam diffusion duct 6, as will be shown below.

In the following, "peripheral diffusion conduits" 4, 5 will be used to refer to the two diffusion conduits arranged in the space 3, and "inner diffusion conduit" 6 refers to the tube arranged inside the basket 2. In the embodiment shown, the inner diffuser pipe 6 is coaxial with the basket 2 (in which case it may be referred to as the central diffuser pipe 6).

In the embodiment shown, one of the peripheral diffusion ducts 4 has two steam air inlets via a connection with the steam supply ducts 30, 31 and has one end at the top, which is open or closed. One of the steam inlets is advantageously arranged in the lower part of the chamber 1, facing the bottom of the basket 2; the other steam inlet is arranged above at least half of the basket 2. This arrangement has the advantage of ensuring that the steam spreads over the entire height of the basket 2.

The other peripheral diffusion conduit 5 has a steam inlet via a connection with a steam supply conduit 50 and an outlet 51 opening into the inner diffusion conduit 6. In the embodiment shown, the peripheral diffusion conduit 5 has an end portion 50, which end portion 50 is inserted into the inner diffusion conduit 6 while passing through the upper end opening of the inner diffusion conduit 6. The end portion 50 of the diffuser pipe thus constitutes a steam inlet in the inner diffuser pipe 6.

The peripheral diffusion conduits 4, 5 and the inner diffusion conduit 6 each have microporous walls to allow diffusion of the vapor. The diffusion of the vapor is illustrated by arrows in the figure. Thus, the steam circulating in the peripheral diffusion ducts 4, 5 diffuses through the walls of the ducts, then through the walls of the microporous basket 2 at the level of the ducts, and through the inner diffusion duct 6, the steam also diffusing through the walls of the inner diffusion duct 6. Thus, the basket containing the rice to be precooked is "fed" with steam through the two peripheral ducts 4, 5 and the inner duct 6. This arrangement thus makes it possible to achieve a uniform precooking of all the rice grains placed in the basket, including the rice grains located in the center of the basket (due to the presence of the internal duct 6).

Advantageously, the lower part of the microporous basket 2 has a cylindrical unloading compartment, the internal diffusion duct 6 being positioned so that the microporous or open (lower) front end is located at a distance of less than or equal to 350 mm (preferably, less than or equal to 250 mm) from the wall of the cylindrical compartment.

The rice grains were pretreated as follows.

The untreated rice to be precooked is poured into basket 2. The chamber 1 is then closed to seal it and the valve associated with the vacuum tank is opened to connect the vacuum tank and the chamber and thereby evacuate the chamber. The chamber thus changes from atmospheric pressure to a negative pressure of about 0.6 bar in about ten seconds. When the negative pressure tends to plateau, the valve closes. After a negative pressure of at least twenty seconds, steam is injected inside each peripheral diffusion duct via the steam supply duct 30, 31, 50 at a temperature of 130 ℃ to 190 ℃ and a pressure of 5 bar to 10 bar.

The pressure is maintained for about 20 seconds, during which steam circulates in the peripheral diffusion duct, with some of the steam diffusing through the walls of the diffusion duct and the basket and circulating in the inner diffusion duct 6. The pressure is then brought back to atmospheric pressure by opening a vent provided for this purpose.

After an interval of about ten seconds, a new vacuum is applied by opening the valve again to connect the chamber to the vacuum tank, which has been brought back to negative pressure by the vacuum pump at the same time. A negative pressure of about 0.6 bar was reached in about ten seconds, then maintained for about 80 seconds, after which time venting was performed to return the chamber to atmospheric pressure.

The entire pretreatment is completed in less than 300 seconds.

The invention has been described above by way of example. It should be understood that those skilled in the art can produce various alternative embodiments of the invention without departing from the scope of the invention.