FR3139436A3 - Process for treating plant products and corresponding processing unit - Google Patents

Abstract

Process for treating plant products and corresponding processing unit The process is intended for the treatment of plant products packaged in perforated containers. It includes the following steps: - stacking the containers (5) by forming several stacks (7), each stack (7) having a height of between 1 and 2.5 m and a horizontal section of between 0.5 and 1.5 m²;- loading of only one of the piles (7) in a first treatment cabin (9);- showering of the pile (7) loaded in the first treatment cabin (9);- unloading of the pile (7) outside the first treatment cabin (9);- loading of only one of the piles (7) in a second treatment cabin (15);- showering of the pile (7) loaded in the second treatment cabin (15) ;- unloading the pile (7) out of the second treatment cabin (15); the steps of loading and unloading the first treatment cabin (9) being carried out during the step of showering the second treatment cabin ( 15), and the steps of loading and unloading the second treatment cabin (15) being carried out during the step of showering the first treatment cabin (9). Figure for abstract: 1

Description

Process for treating plant products and corresponding processing unit

The present invention relates to a process for treating plant products.

It is important that plant products such as fruits and vegetables do not lose their organoleptic qualities and maintain an attractive appearance when placed on the market for rapid consumption. However, after harvest, plant products are commonly stored for relatively long periods before being placed on the market.

Phenomena likely to alter the appearance and taste of plant products include the proliferation of fungi and bacteria on their surface. This deterioration is even more rapid at the level of micro injuries and cuts appearing on the skin during storage or handling of plant products. Another phenomenon likely to damage plant products is the phenomenon of scalding which manifests itself by blackening of the skin of the affected plant products.

We know different treatments for plant products, including thermotherapy which consists of the application of a hot treatment composition, for example water. Other treatments consist, for example, of the use of treatment compositions comprising fungicides such as eugenol.

FR 2909525 A1 proposes a process and an installation adapted for the thermotherapy of plant products. Plant products are packaged in boxes. They are treated in a large volume shower cabin. Means for showering the plant products contained in the boxes are provided in the cabin, the sprinkling being carried out by hot water possibly containing additives.

It is possible to obtain a high processing rate with this process, due to the large volume of plant products that can be loaded inside the cabin.

On the other hand, the heating power required to maintain hot water is very high in an installation of this type.

In this context, the invention aims to propose a method and a treatment installation which make it possible to reduce the heating power required, without compromising the quality of the treatment, while maintaining a high processing rate.

To this end, the invention according to a first aspect relates to a process for treating plant products packaged in perforated containers, the process comprising the following steps:

- stacking of containers forming several piles, each pile having a height of between 1 and 2.5 m and a horizontal section of between 0.5 and 1.5 m²;
- loading only one of the stacks in a first processing cabin comprising a belt of side walls, at least one of the side walls being deformable between an engagement configuration and a stack release configuration;

- setting the stack engagement configuration of the or each deformable side wall of the first treatment cabin;

- showering the pile loaded in the first treatment cabin with a treatment composition having a temperature of between 30°C and 60°C, with a flow rate of between 160 and 300m ³ /m ² /h and for a duration of between 10s and 10 minutes;
- unloading the pile out of the first treatment cabin;
- loading only one of the stacks in a second processing cabin comprising a belt of side walls, at least one of the side walls being deformable between an engagement configuration and a stack release configuration;

- setting the stack engagement configuration of the or each deformable side wall of the second treatment cabin;

- showering the pile loaded in the second treatment cabin with a treatment composition having a temperature of between 30°C and 60°C, with a flow rate of between 50 and 500m ³ /m ² /h and for a duration of between 10s and 10 minutes;
- unloading the pile out of the second treatment cabin;
the steps of loading and unloading the first treatment cabin being carried out during the step of showering the second treatment cabin, and the steps of loading and unloading the second treatment cabin being carried out during the step of showering the first treatment cabin..

Each processing cabin has a limited volume, due to the fact that it is sized to load a stack of containers of modest volume. As a result, the flow rate of the treatment composition is significantly lower than in FR 2909525. The power required for heating this treatment composition is therefore significantly less.

As the two treatment cabins are used alternately, in masked time, the liquid flow at each moment is moderate. On the other hand, the flow rate of liquid composition per m² and per hour is higher than in FR 2909525. The quality of processing is improved.

The volume of plant products treated in each cycle in a treatment cabin is lower than in FR 2909525. On the other hand, due to the fact that the two treatment cabins work in masked time, the treatment capacity is only slightly impacted.

The treatment process may have one or more of the characteristics below, considered individually or in all technically possible combinations:

- each pile includes between one and six containers per level;

- the first treatment cabin and the second treatment cabin are supplied from the same reserve of treatment composition;

- the reserve of treating composition is heated continuously;

- the flow rate of treatment composition in the showering step in the first treatment cabin and in the second treatment cabin is between 60 and 600 m ³ /h.

According to a second aspect, the invention relates to a unit for processing plant products packaged in perforated containers, the containers forming several stacks, each stack having a height of between 1 and 2.5 m and a horizontal section of between 0, 5 and 1.5 m², the treatment unit comprising:

- a first treatment cabin of a size adapted to receive only one of the piles, the first treatment cabin comprising a belt of side walls, at least one of the side walls being deformable between an engagement configuration and a configuration for releasing the pile;

- a second treatment cabin of a size adapted to receive only one of the piles, the second treatment cabin comprising a belt of side walls, at least one of the side walls being deformable between an engagement configuration and a configuration for releasing the pile;

- a circuit for showering the pile loaded in the first treatment cabin with a treatment composition;

- a circuit for showering the pile loaded in the second treatment cabin with the treatment composition;

- means of heating the treatment composition, and

- a system for deforming the deformable walls of the first treatment cabin and a system for deforming the deformable walls of the second treatment cabin.

The processing unit may also have one or more of the characteristics below, considered individually or in all technically possible combinations:

- the shower circuit of the first treatment cabin and the shower circuit of the second treatment cabin are supplied by the same reserve of treatment composition;

- the heating means heat the treatment composition contained in the reserve;

- the heating means have a power of between 500 and 1200 kW;

- the flow rate of treatment composition in the shower circuit of the first treatment cabin and in the shower circuit of the second treatment cabin is between 50 and 500 m ³ /m²/h.

Other characteristics and advantages of the invention will emerge from the detailed description given below, for information only and in no way limiting, with reference to the appended figures, among which:

• Figures 1 and 2 are perspective views of the treatment installation of the invention, considered from the front side and the rear side respectively; And
• There is a schematic elevation representation of a stack of containers loaded with plant products.

The processing unit 1 shown in Figures 1 and 2 is intended to process plant products 3 packaged in perforated containers 5, the containers 5 forming several stacks 7 of the type shown in the .

Plant products are fruits or vegetables.

The fruits are for example apples, pears, or any other suitable type of fruit.

Vegetables are for example potatoes, or any other suitable type of vegetable.

The containers 5 are small, for example:

Type 1: length 1.2m, width 1m, height 0.65m;

Type 2: length 1.2 m, width 1 m, height 0.35 m;

Type 3: length 0.45 m, width 0.30 m, height 0.30 m.

The containers are for example boxes, pallet boxes, or any other type of suitable container.

They are perforated in the sense that the treatment composition projected onto the plant products packaged in the container can flow through the container. The bottom of the container in particular has holes not shown for the flow of the treatment composition.

Each pile 7 has a height of between 1 and 2.5 m and a horizontal section of between 0.5 and 1.5 m².

Each pile 7 preferably has a height of between 1.5 and 2.5 m and a horizontal section of between 0.8 and 1.3 m².

Each 7 stack has between one and six 5 containers per level.

Stack 7 has between three and ten levels.

When the containers are larger, pile 7 has only one container 5 per level. It then has between three and five levels.

When the containers are smaller, the stack 7 typically has four or six containers 5 per level. It then has between six and ten levels.

For type 1 containers, stack 7 has one container 5 per level and three levels.

For type 2 containers, stack 7 has one container 5 per level and five levels.

For type 1 containers, stack 7 has six containers 5 per level and eight levels.

Each container 5 receives a mass of plant products of between 1 and 25 kg, preferably between 5 and 20 kg.

The processing unit 1 comprises a first processing cabin 9, of a size adapted to receive a stack 7 of the size indicated above, that is to say a stack 7 of a height between 1 and 2, 5 m and a horizontal section of between 0.5 and 1.5 m².

The first treatment cabin 9 internally delimits a housing having a height and, perpendicular to the vertical direction, a section corresponding substantially to the height and the section of a single pile 7.

The housing is thus adapted to receive a pile 7 with a height of between 1 and 2.5 m and a horizontal section of between 0.5 and 1.5 m².

The first cabin 9 comprises a belt of side walls 11, 13, at least one of the side walls 11 being deformable between an engagement configuration and a release configuration of the stack 7.

The processing unit 1 further comprises a second processing cabin 15, of a size adapted to receive only one of the batteries 7.

The second cabin 15 also comprises a belt of side walls 11, 13, at least one of the side walls 11 being deformable between an engagement configuration and a release configuration of the stack 7.

The first treatment cabin 9 and the second treatment cabin 15 are preferably identical to each other.

Two of the side walls, referenced 11, are deformable between the engagement configuration and the release configuration. They are opposite each other,

The other two side walls, referenced 13, are rigid and are typically made of metal sheet. They face each other.

One of the walls 13 is fixed and constitutes the rear of the treatment cabin.

The other wall 13 is a door allowing access to the interior of the treatment cabin and loading/unloading the pile 7. It constitutes the front of the treatment cabin. It is of any suitable type.

The walls 11 in the exemplary embodiment are inflatable walls. Each of the two walls comprises a rigid exterior face and a flexible interior face, for example made of polyester.

The inflation of this wall 11 and its passage into the engagement configuration are ensured by introducing a fluid such as compressed air between its interior and exterior faces, which causes the interior face to press against the stack of boxes 7 placed inside the accommodation.

The treatment unit 1 further comprises a circuit 17 for showering the pile 7 loaded in the first treatment cabin 9 by a treatment composition, and a circuit 19 for showering the pile 7 loaded in the second treatment cabin 15 by the same treatment composition.

The shower circuits 17 and 19 are supplied by the same reserve 21 of treatment composition.

Reserve 21 is a tank placed under the two treatment cabins 9 and 15.

The showering circuit 17 comprises a spray ramp 23 arranged in or on the cabin 9, above the stack 7. It also includes a conduit 25 fluidly connecting the ramp 23 to a collector 27 for distributing the treatment composition.

A solenoid valve 29 is inserted in the conduit 25, so as to authorize or prohibit the circulation of the treatment composition from the collector 27 to the distribution ramps 23.

The shower circuit 19 of the pile 7 loaded in the second treatment cabin 15 is of the same type. It also includes a spray boom 31 arranged in or on the cabin, above the stack 7 of containers 5, as well as a conduit 33 connecting the spray boom 31 to the collector 27.

A solenoid valve 35, inserted on the conduit 33, authorizes or prohibits the circulation of treatment composition from the collector 27 to the spray boom 31.

As visible on the , the treatment unit 1 comprises a circulation member 37 of the treatment composition, the suction of which is fluidly connected to the reserve 21, and the discharge of which is connected to the collector 27.

The circulation member 37 is a pump, typically a centrifugal pump.

Unit 1 also includes means 39 for heating the treatment composition. In the example shown, the heating means 39 heat the treatment composition contained in the reserve 21.

To do this, the heating means 39 typically comprise a heat exchanger 41 immersed in the reserve 21. A heat transfer fluid circulates in the heat exchanger.

The heat exchanger 41 is shown schematically on the . It is of any suitable type.

The heating means 39 comprise in this case a boiler 43 configured to heat the heat transfer fluid, and a circuit 45 fluidly connecting the boiler 43 to the heat exchanger 41. The circuit 45 comprises a circulation member 47 such as a pump , ensuring the loop circulation of the heat transfer fluid between the boiler 43 and the heat exchanger 41.

Boiler 43 is an electric boiler, or a gas boiler, or any other type of boiler.

Unit 1 also includes a system 49 for deforming the deformable walls 11 of the first treatment cabin 9, and a system 51 for deforming the deformable walls 11 of the second treatment cabin 15.

The two systems are identical.

Each of the two systems allows the inflation of the walls 11. It comprises a blowing member 52 such as a fan, and conduits 53 connecting the discharge of the blowing member 52 to the volume delimited between the exterior face and the interior face of wall 11.

Each of the two treatment cabins 9, 15 is delimited downwards by a bottom 55 placed immediately above the tray 21 ( ). This bottom 55 is perforated to allow the treatment composition to flow from the internal volume of the cabin into the reserve 21. The stack 7 of containers is placed on the bottom 55.

The heating means 39 have a heating power of between 500 and 1200 kW, preferably between 600 and 1000 kW, and worth for example 800 kW.

The circulation member 37 is dimensioned to provide a flow rate of treatment composition of between 60 m ³ and 600 m ³ per hour.

In each of the two treatment cabins 9, 15, the flow rate of treatment composition in the showering step is between 50 m ³ and 500 m ³ per m ² and per hour, preferably between 100 and 300 m ³ per m ² and per hour.

This corresponds to a treatment composition flow rate of between 60 m ³ to 600 m ³ per hour, distributed over the horizontal section of the cabin, this section being for example approximately 1.2 m ² .

The processing unit 1 also includes a controller 57, which controls, among other things, the showering circuits 17 and 19, the heating means 39 and the wall deformation systems 49 and 51.

The controller 57 controls in particular the circulation member 37, the solenoid valves 29 and 35, the boiler 43, the circulation member 47, and the blowing members 51.

The controller 57 regulates the temperature of the treatment composition within the range indicated above, and controls the flow rate of the treatment composition so that it is within the range indicated above.

A process for treating plant products packaged in perforated containers will now be described.

This process is intended to be implemented using the processing unit 1 described above. Conversely, the processing unit 1 is specially designed to implement the treatment process.

The plant products packaged in the containers are as described above.

The containers are openwork containers of the type described above.

The treatment method includes a step of stacking the containers 5 by forming several piles 7, each pile 7 having a height of between 1 and 2.5 m and a horizontal section of between 0.5 and 1.5 m².

Each pile 7 preferably has a height of between 1.5 and 2.5 m and a horizontal section of between 0.8 and 1.3 m².

Each 7 stack has between one and six 5 containers per level.

Stack 7 has between three and ten levels.

The batteries are as described above.

The treatment method also includes a step of loading only one of the batteries 7 into a first treatment cabin 9.

The first treatment cabin 9 comprises a belt of side walls 11, 13, at least one of the side walls being deformable between an engagement configuration and a release configuration of the stack 7.

The first treatment cabin 9 is of the type described above.

The side wall belt 11, 13 internally delimits a housing of section and height adapted to receive only one battery 7.

The method further comprises a step of setting the stack engagement configuration of the or each deformable side wall 11 of the first treatment cabin 9, followed by a step of showering the stack 7 loaded in the first processing cabin. treatment 9 with a treatment composition.

Putting the stack engagement configuration of the or each deformable side wall 11 is obtained by inflating the side wall 11 with a fluid such as air.

The air is delivered into the internal volume of the side wall 11 as described above by the circulation member 51 of the system 49 for deforming the deformable walls 11.

In the engagement configuration, the interior face of the wall 11 is pressed against the stack 7 of containers. Furthermore, the stack 7 of containers rests towards the rear against the fixed wall 13, and towards the front against the wall 13 acting as a loading door.

Thus, the treatment composition is forced to circulate through the stack 7 of perforated containers.

The showering of the stack 7 is ensured by the showering circuit 17. The treatment composition is projected by the spray ramp 23 above the stack 7. It flows through the different containers 5 by gravity from the spray ramp. sprinkler 23 up to grid 55.

At the end of the showering step, the process includes a step of unloading the pile 7 out of the first cabin 9.

To do this, the loading door of the first cabin 9 is open, and an operator comes to extract the pile 7 out of the cabin.

It then loads a new stack 7 inside the first processing booth 9, and a new processing cycle inside the first processing booth 9 is launched.

Furthermore, the method includes a step of loading only one of the batteries 7 in a second treatment cabin 15.

The second treatment cabin 15 is as described above.

The method then comprises a step of setting the stack engagement configuration of the or each deformable wall 11 of the second treatment cabin 15, and a step of showering the stack 7 loaded into the second treatment cabin 15 by the treatment composition.

The steps of setting the engagement and showering configuration are as described in relation to the first treatment cabin 9.

At the end of the showering step, the process includes a step of unloading the pile 7 out of the second cabin 15.

This unloading step is carried out as described above in relation to the first cabin 9.

The unloading step is followed by a step of loading a new pile 7 into the second treatment cabin 15, and a new showering cycle inside the second treatment cabin 15 is then initiated.

Advantageously, the loading and unloading steps of the first treatment cabin 9 are carried out during the showering step in the second treatment cabin 15.

Conversely, the loading and unloading steps of the second treatment cabin 15 are carried out during the showering step of the first treatment cabin 9.

Thus, the loading and unloading of the first treatment cabin 9 is carried out in masked time during showering in the second treatment cabin 15.

In the same way, the loading and unloading of the second treatment cabin 15 is carried out in masked time during showering in the first treatment cabin 9.

The method of the invention therefore makes it possible to carry out continuous processing, without completely stopping the processing unit to load or unload the stacks of containers. While one of the cabins is stopped, the other cabin is in operation.

The treatment composition used for showering has a temperature between 30°C and 60°C. Advantageously, it has a temperature of between 45°C and 55°C.

To do this, the reserve 21 of treatment composition is heated continuously. It is heated using heating means 39.

In each of the two treatment cabins, the flow rate of treatment composition in the showering step is between 50 and 500 m ³ per m ² and per hour, preferably between 100 and 300 m ³ per m ² and per hour.

This corresponds to a treatment composition flow rate of between 60 m ³ to 600 m ³ per hour, distributed over the horizontal section of the cabin, this section being for example approximately 1.2 m ² .

During the showering step in the first treatment cabin 9, the circulation member 37 is in operation. It draws the treatment composition from the reserve 21, and delivers it into the shower circuit 17 of the first cabin 9. The solenoid valve 29 is open, while the solenoid valve 35 serving the shower circuit 19 of the second cabin 15 is closed.

Conversely, during the showering step in the second treatment cabin 15, the circulation member 37 is in operation, the solenoid valve 29 is closed and the solenoid valve 35 is open.

The showering step has a duration typically between 10 seconds and 10 minutes, preferably between 1 and 5 minutes, and ideally worth between 2 and 3 minutes.

The treatment composition is of any suitable type.

For example, the treatment composition is water not containing any particular active compound. Alternatively, the treatment composition is water containing phosphonic acid (HPO ₃ H ₂ ), also called phosphorous acid H ₃ PO ₃ .

The method and the processing unit described above may have multiple variants.

Each treatment cabin may have a single deformable side wall, or more than two deformable side walls, for example three or four deformable side walls.

The treatment unit could include more than two treatment cabins operating in masked time. The treatment unit can thus include three independent treatment cabins, or more than three independent treatment cabins. One or more of the treatment cabins are used for showering, while one or more other treatment cabins are loading/unloading.

All the cabins are arranged above the same reserve of treatment composition, each cabin being able to treat a single stack of containers.

It is possible to provide a dedicated shower circuit for each cabin, with its own circulation system.

The heating means may include an electric heating member, such as a resistor, directly immersed in the reserve of treating composition.

Claims (10)

Process for treating plant products packaged in perforated containers, the process comprising the following steps:
- stacking the containers (5) by forming several stacks (7), each stack (7) having a height of between 1 and 2.5 m and a horizontal section of between 0.5 and 1.5 m²;
- loading of only one of the piles (7) in a first treatment cabin (9) comprising a belt of side walls (11, 13), at least one (11) of the side walls being deformable between an engagement configuration and a stack release configuration;
- setting the stack engagement configuration of the or each deformable side wall (11) of the first treatment cabin (9);
- showering the pile (7) loaded in the first treatment cabin (9) with a treatment composition having a temperature between 30°C and 60°C, with a flow rate between 160 and 300m ³ /m ² /h and for a period of between 10s and 10mn;
- unloading the pile (7) out of the first treatment cabin (9);
- loading of only one of the piles (7) in a second processing cabin (15) comprising a belt of side walls (11, 13), at least one (11) of the side walls being deformable between an engagement configuration and a stack release configuration;
- setting the stack engagement configuration of the or each deformable side wall (11) of the second treatment cabin (15);
- showering the pile (7) loaded in the second treatment cabin (15) with a treatment composition having a temperature between 30°C and 60°C, with a flow rate between 50 and 500m ³ /m ² /h and for a period of between 10s and 10mn;
- unloading the pile (7) out of the second treatment cabin (15);
the steps of loading and unloading the first treatment cabin (9) being carried out during the step of showering the second treatment cabin (15), and the steps of loading and unloading the second treatment cabin (15) being carried out during the showering step of the first treatment cabin (9). Method according to claim 1, wherein each stack comprises between one and six containers (5) per level. Method according to claim 1 or 2, in which the first treatment cabin (9) and the second treatment cabin (15) are supplied from the same reserve (21) of treatment composition. Method according to claim 3, in which the reserve (21) of treatment composition is heated continuously. Method according to any one of the preceding claims, in which the flow rate of treatment composition in the showering step in the first treatment cabin (9) and in the second treatment cabin (15) is between 60 and 600 m ³ /h. Unit for processing plant products packaged in perforated containers (5), the containers (5) forming several stacks (7), each stack (7) having a height of between 1 and 2.5 m and a horizontal section of between 0 .5 and 1.5 m², the processing unit (1) comprising:
- a first treatment cabin (9) of size adapted to receive only one of the piles (7), the first treatment cabin (9) comprising a belt of side walls (11, 13), at least one (11) of the walls lateral being deformable between an engagement configuration and a release configuration of the stack;
- a second treatment cabin (15) of size adapted to receive only one of the piles (7), the second treatment cabin (15) comprising a belt of side walls (11, 13), at least one (11) of the walls lateral being deformable between an engagement configuration and a release configuration of the stack;
- a circuit (17) for showering the pile (7) loaded in the first treatment cabin (9) with a treatment composition;
- a circuit (19) for showering the pile (7) loaded in the second treatment cabin (15) with the treatment composition;
- means (39) for heating the treatment composition, and
- a system (49) for deforming the deformable walls (11) of the first treatment cabin (9) and a system (51) for deforming the deformable walls (11) of the second treatment cabin (15). Treatment unit according to claim 6, in which the showering circuit (17) of the first treatment cabin (9) and the showering circuit (19) of the second treatment cabin (15) are supplied by the same reserve ( 21) of treatment composition. Treatment unit according to claim 7, in which the heating means (39) heat the treatment composition contained in the reserve (21). Processing unit according to any one of claims 6 to 8, in which the heating means (39) have a power of between 500 and 1200 kW. Treatment unit according to any one of claims 6 to 9, in which the flow rate of treatment composition in the showering circuit (17) of the first treatment cabin (9) and in the showering circuit (19) of the second treatment cabin (15) is between 50 and 500 m ³ /m²/h.