DE102021000553A1 - Method and device for sanitizing returnable containers, in particular box-like plastic returnable containers - Google Patents

Abstract

The invention relates to a method and a device for sanitizing and drying washable, in particular box-like, goods containers. According to the invention, in the course of preparatory process steps, a thorough cleaning is carried out until the goods containers are visually clean, and in the context of a subsequent process step, at least the interior of the goods container is exposed to steam. This steam is applied via a nozzle system to the inner wall of the respective container to be treated and this steam application is carried out in such a way that steam is applied over the entire surface of the container with deflection of the jet, at least with regard to the inner wall of the container.

Description

Background of the invention

In Europe, a large number of plastic boxes are filled with fresh, unpackaged food, especially meat, bread, etc., and transported both within a processing plant and externally, e.g. to a customer. Some of these containers are also used throughout the EU as reusable load carriers, especially in the form of standardized containers, e.g. the so-called El-3 box.

In order to keep the use of plastic film to a minimum and to prevent the risk of unwanted entry of foreign bodies (foreign particles), inserts are avoided as far as possible in fresh products. International efforts are also going in this direction from the point of view of sustainability. Dispensing with such inserts, however, requires the containers to have a high hygienic status, especially shortly before they are refilled and before they come into direct contact with food. The cleaning and in particular the final disinfection are legally regulated in the standards EU-VO 852-854 / 2004. This stipulates the water treatment of all food contact surfaces using hot water with a temperature of at least + 82 ° C, or alternatively an equivalent / better method. If biocides are used for the final disinfection, their residues must be removed again for toxicological reasons. Processes that are specifically approved as so-called "non rinse applications" are an exception.

Post-drying is required with the known practical methods. So far, this has mainly been done by powerful blowers that blow cleaning and residual water from the containers at high airflow speeds. This creates aerosols and swirls of germs that are in the rooms and washing systems (continuous systems).

Sterilized and dry boxes are an essential prerequisite for being able to hold food in them in direct contact with the wall. Too much residual moisture between the inserted products and the box would otherwise encourage germ growth and is therefore not allowed. In addition, containers with excessive residual moisture significantly increase the humidity in the storage and dismantling rooms. This can lead to the dew point being exceeded in cold meat in cutting rooms or to mold growth in storage rooms. The latter must then be dried by strong cooling. These approaches are associated with a high use of energy.

Furthermore, systems are known in which the containers are dried by means of centrifugal acceleration. These are discontinuous systems, which in some cases have a considerable influence on the process of the upstream conveyor washing machines (stop and go and often two machines are necessary to achieve the required performance). The energy and cost expenditure of such systems (centrifugal systems) is also considerable and hardly affordable for small and medium-sized companies.

Object of the invention

The invention is based on the object of creating solutions by means of which it is possible, when using box-like reusable containers, to achieve adequate sanitation and drying and a high degree of purity before they are filled.

Solution according to the invention

The above-mentioned object is achieved according to the invention by a method for treating washable goods containers, in which, as part of preparatory process steps, the goods containers are thoroughly cleaned and, as part of a subsequent method step, at least the interior of the goods container is subjected to steam, this steam at least being applied via a nozzle system the inner wall of the respective container to be treated is applied and this steam application is carried out in such a way that at least with regard to the inner wall of the container, the entire surface is wetted. This steam is preferably steam which, with regard to its thermal state, is represented in particular as dry steam or also in particular as superheated steam.

This makes it possible in a surprisingly effective way, dispensing with other additives, a high degree of sterility and in connection with dehumidification measures, such as suction, blowing and / or vibration (shaking), or a combination of the same measures, a reliable drying of the boxes guarantee.

After the application of steam, with sufficient exposure time, the residual water is preferably removed by vibration (shaking), suction, or blowing off steam, air and / or condensate from the interior or the immediate vicinity of the container.

It is possible to adjust the suction volume from the area surrounding the container and the steam and supply air volume in such a way that the smallest possible after-flow of untreated or unfiltered air into the interior of the system and the container that has just been cleaned takes place. It is possible to combine the drying measures with one another and to coordinate their respective intensity with the type of container and a selected treatment program.

The steam preferably has a temperature of at least 120 °, in particular 180 °. The steam preferably has a total pressure of at least 2, preferably approximately 8, bar shortly before the nozzle outlet. The steam nozzle system is preferably designed in such a way that at least the entire inner wall of the container is exposed to steam intensively for a sufficiently long time and thus sufficient sterilization takes place.

The nozzle system and the container are preferably path-controlled or moved against one another by a mechanism. The course of the path is preferably coordinated in such a way that a steam front migrating out of the container results.

In addition, the steam input is preferably coordinated in such a way that, together with the upstream container washing, a certain amount of wall heating of the container results, which ensures or at least supports the self-drying of the container.

The superheated steam is preferably generated by a heated nozzle system or a heat exchanger system directly upstream of the nozzle system. The steam can be generated by heating the water introduced there to approx. 180 degrees Celsius in a boiler (boiler) and then evaporating it at a pressure of 8-10 bar at approx. 180 degrees Celsius.

The nozzle system can comprise movable nozzles, in particular nozzles which, under the effect of the emitted steam, execute their own movement, in particular a rotary movement. The nozzles can be moved relative to the container via a path control system. The container itself can be moved during the application of steam. The relative movement between the nozzles and the container can be brought about at the time of the application of steam by the nozzles' own movement, the container's own movement and / or joint coordinated movement of the nozzles and the container.

The steam can be applied by a controlled moving nozzle or by a nozzle system with several nozzles. When using several nozzles, these nozzles can be moved in a controlled manner relative to one another. If several nozzles are used, they can be arranged in such a way that the steam is emitted in different directions. Certain nozzles can serve primarily to apply steam to the bottom of the container and other nozzles primarily to apply steam to the inner surface of the container side wall. Preferably, the respective container is also actively acted upon with water vapor in its outer area.

The interior area is preferably exposed to steam in such a way that the interior area already exposed to steam spreads out from a specific starting area. Here, for example, a steam front migrates towards the edge area of the container. The application of steam can be carried out in an advantageous manner in such a way that there is as little reflection of deflected steam as possible on the zones that have already been treated.

The application of steam, preferably dry steam, to the inner surface of the container, preferably blown off by several spray jets, can be controlled in such a way that first the inner corners of the container are blown out, then the inner area is roughly painted over for the first time, and then the inner surface is subjected to a path-controlled application of the inner surface in such a way that successively the entire inner surface of the container is temporarily effective as a beam deflecting surface on which a beam is deflected or deflected by at least 30 °. Preferably, the bottom area of the container is first treated by the application of steam, then the side wall. The jet direction is preferably selected so that any contamination and any water droplets are blown out of the container with the main jet direction as far as possible.

According to a further aspect of the present invention, the object specified at the beginning is also achieved according to the invention by a device for carrying out the method described above with a nozzle system for applying hot or dry steam to the interior of the pre-cleaned containers, this steam having a temperature in the range of preferably 120 ° and is actively radiated into the inner area in such a way that the entire inner surface of the inner area of the container to be treated presents itself as a beam-deflecting impact surface.

The container is preferably acted upon with steam in a position in which the inner bottom of the container is inclined, in particular is inclined to such an extent that any condensate on the inner surface of the side wall can drain downwards. The container is preferably fixed during the application of steam. The container can in particular in the overhead position, ie are treated in a position in which the bottom underside of the top knows.

It is possible to provide means in the area of the device by which the treatment of the container is documented. In particular, marking or printing can be carried out on the container, thus documenting the treatment and, if applicable, its parameters. In particular, the date, time, steam temperature, steam pressure and treatment duration can be documented. The documentation can be done in particular by a print head or a jet printing process, e.g. an inkjet printing process with washable, aseptic ink.

The device according to the invention can be implemented as a module for an established cleaning system that includes, for example, a washing installation. It can also be integrated into an existing washing system, in particular in the form of a retrofit kit. If the device according to the invention is implemented as a module, it can be coupled to the further cleaning system via lock sections, so that, for example, the treatment area is sealed off from the unclean inlet area during the application of steam.

This inlet area is only opened after the treated container has left the application area through another lock. The module can be constructed in such a way that it forms a treatment section with an inlet area and an outlet area, these two areas being spaced apart from one another in the flow direction. The module can have lateral opening flaps, doors or windows via which the treatment path or at least sections thereof are accessible or visible from the side.

The containers can be moved through the device in such a way that they change their orientation therein. In this way, the containers can be guided in the system in an orientation in which the base is initially oriented essentially vertically. During the application of steam, the container is increasingly tilted until its bottom is aligned horizontally and the back of the bottom is facing up. In this position the steam is then preferably applied by moving nozzles vertically from below and the steam flow of the returning steam can flow down into a condensate collecting basin.

The system according to the invention can be implemented as a retrofit module or built-in device that can be integrated into existing cleaning systems. In a separate module, the previously used technique of post-rinsing and drying is preferably replaced by a dry steam technique with immediately following vibration, suction or blow-off. Steam with a temperature of around 120 ° C or in particular 180 ° at a pressure of up to 8 bar and a special nozzle system is evenly distributed and applied to the inside and outside of the container in such a way that complete wetting takes place. High germ killing rates can be achieved, which are above the values of the conventional 82 ° C hot water rinse. Nevertheless, no residue is left behind. The residual water is removed by an immediately following vibration and / or suction, there is no turbulence and thus no secondary contamination (from contaminated air) in this area of the system.

Due to the construction of the boxes with stabilizing elements on the outer surfaces, suction is technically more difficult to solve. However, due to the use of dry steam, the crates have a certain “self-drying and post-drying effect”, which allows them to achieve at least the same residual water content as conventional blow-off systems.

Special features of the new procedure

1. 1) According to the inventive concept, cleaning is separated from sanitizing and drying
2. 2) On cleaned surfaces, the steam can develop its germicidal properties with high effectiveness, without residue, without subsequent secondary contamination, etc.
3. 3) The following process step of vibration and / or suction prevents the turbulence of air containing germs and thus also the exposure to germs after the disinfection process.
4. 4) Savings in energy and water, such as hot water (no heating of approx. 80K), no dilution effect due to cascade-like water dilution from the final rinse to the main wash and thus chemical savings (do not continuously re-dose). Steam generation and suction require less electrical energy than hot water, pumps, blowers and a conventional phrase extract. The water saving effect is significant (> 1 1 / container therefore also less wastewater, etc.).

The steam generation can be accomplished by systems such as flow heaters or boilers. The steam is preferably reheated in such a way that at least saturated steam, but preferably hot or dry steam, is produced. The nozzles and nozzle arrangement are preferably designed in such a way that they provide efficient sanitation while at the same time largely displacing the adhesive water droplets from the condensate of the steam.

The sanitation and drying take place in separate work steps. The condensate of the injected steam is removed in a defined manner, so that recontamination due to excessive ambient air flow is avoided.

The walls of the containers are heated by the steam treatment, which promotes their own drying.

Figure list

• 1 eine perspektivische Darstellung einer erfindungsgemäßen Anlage zur Hygienisierung und Trocknung von Mehrweg-Kisten;
• 2 eine Skizze zur Veranschaulichung der Abfolge der Aufbereitung von Mehrwegbehältern durch die Stationen der Reinigung, der Dampfbeaufschlagung und Trocknung hindurch.

Further details and features of the invention emerge from the following description in conjunction with the drawing. It shows:

• 1 a perspective view of a system according to the invention for sanitizing and drying reusable boxes;
• 2 a sketch to illustrate the sequence of reprocessing of reusable containers through the stations of cleaning, steam application and drying.

The representation after 1 shows a simplified perspective view of a system according to the invention for treating washable goods containers. This system comprises a container transport device. Through this container transport device, the washable, here box-like plastic containers are conveyed through subsequent stations. This takes place within this system in a first washing station S1 and the preparatory process steps taking place therein, a thorough cleaning of the goods containers.

Within a subsequent station in the transport direction of the container S2 As part of a process step treating the container, steam is applied to at least the inner area of the goods container, this steam being applied via a nozzle system at least to the inner wall of the respective container to be treated, and this steam application is carried out in such a way that at least with regard to the inner wall of the container, a full-area Wetting takes place. The steam is provided at a pressure level selected for the treatment and with a likewise selected volume flow via a heating device by heating water. This steam is preferably water vapor, which, with regard to its thermal state, presents itself as dry steam or, for example, also as superheated steam.

This water vapor achieves a high degree of sterility, preferably without any other additives.

As part of a drying station following the steam application station, the container advancing into this station is subjected to dehumidification measures, in particular suction, blowing and / or vibration (shaking), or a combination of the same measures. This achieves reliable drying of the crates, which is also supported in particular by the heating during the application of steam.

In the transition from the container to the station S2 After the steam has been applied, the residual water is removed by vibration (shaking), suction or blowing off steam, air and / or condensate from the inside or the immediate vicinity of the container.

The suction volume from the area around the container and the steam and supply air volume are coordinated in such a way that the lowest possible flow of untreated or unfiltered air into the interior of the system and thus to the containers that have just been cleaned. In the drying station S3 drying measures are combined with one another and their respective intensity is coordinated with the type of container and a selected treatment program.

The one in the station S2 Steam jetted onto the container here preferably has a temperature of at least 120 °, in particular 180 °. The steam preferably has a total pressure of at least 2, preferably 8 bar shortly before the nozzle outlet. The steam nozzle system is designed in such a way that it acts intensively at least on the entire inner wall of the container, which is open at the bottom and is slightly inclined, for a sufficiently long time, and thus sufficient sterilization takes place.

The nozzle system can advantageously be movable nozzles which, for example, can also be attached to a movable or pivotable or rotatable carrier. In addition, the transport device moves the container past the point of action of the nozzles at a selected, optionally alternating, speed. The speed profile is preferably adjusted so that the potentially germ-contaminated area is "peeled off" via the nozzle system and does not migrate through the nozzle system, but always remains on the side of the container access until the last section of the container has also migrated through the effective location of the nozzles. The admission is like this chosen that as part of the further transport of the container through the station S2 a vapor front that moves through the container and pushes any impurities in front of it or retains it when the container moves.

The entry of steam into the station S2 is coordinated in such a way that, together with the upstream hot water container washing, the walls of the container are heated up, which ensures or at least supports the container's self-drying.

In the drying station S3 the area surrounding the container is actively exposed to filtered, purified and / or dried air. Inside the station S3 a defined overpressure can be maintained in the treatment device, so that no or at most only a slight subsequent flow of ambient air into the interior of the device takes place.

In the station S2 the superheated steam is generated internally by a flow heater and a pump device. However, it can also be taken from one if there is a steam source. The steam can also be generated by heating the water introduced there to approx. 180 degrees Celsius in a boiler (boiler) and then evaporating it at a pressure of 8-10 bar at approx. 180 degrees Celsius.

The station's nozzle system S3 can comprise movable nozzles, in particular nozzles which, under the effect of the emitted steam, execute their own movement, in particular a rotary movement. The nozzles can be moved relative to the container via a mechanical or electronic path control system. The container itself can be moved during the application of steam. The relative movement between the nozzles and the container can be brought about at the time of the application of steam by the nozzles' own movement, the container's own movement and / or joint coordinated movement of the nozzles and the container.

The system according to the invention preferably comprises a housing structure G with an insulated, in particular double-walled structure. The steam application inside the station S2 preferably also captures the transport system, so that no contamination enters the area through it S3 respectively. It is also possible to move the container out of the station S2 in the drying station S3 to be accomplished by a transfer mechanism or by simply pushing the container further. The system has a modular structure, the station S2 is provided here by a module that can also be connected to a conventional car wash as a retrofit module. The case structure G includes flaps G1 , G2 , G3 via which access to the respective work area of the respective station S1 , S2 , S3 is made possible.

The one in the station S3 Recirculated air is passed through a filter and drying device F1 conditioned so that those in the station S2 Do not come into contact with uncleaned air until the treated container is completely dry. In the station S3 there is a slight overpressure, or filtered air is additionally fed into the circulated air, so that due to the air flow balance, unfiltered ambient air does not enter this station.

It is possible due to the overpressure in the station S3 the steam in the station S2 into the station S1 to urge, so that condensation of the same in the washing station S1 he follows. From the washing station S1 air and steam can be extracted; this steam and air flow can be diverted to the unclean side or to the environment.

As from the illustration after 2 can be seen, the containers B1 through the following stations S1 , S2 , S3 and a lock S4 promoted. In the station S1 a thorough cleaning of the container takes place B1 as part of a washing process.

In the station S2 the steam is applied to the interior of the container. This application of steam is brought about in such a way that the inner surface already exposed to steam spreads out from a certain starting area. A steam front moves to the edge of the container B1 are. The steam application is selected in such a way that there is as little reflection of deflected steam as possible on the areas that have already been treated.

The exposure of the inner surface of the container with the dry steam, preferably blown off by several spray jets, is controlled here in such a way that first the inner corners of the container are blown out, then a rough initial painting of the inner area takes place and then a path-controlled inner surface application in such a way that successively the entire inner surface of the container is temporarily acts as a beam deflecting surface on which the beam is deflected by at least 30 °. Here, the bottom area of the container is first used B1 Treated by the application of steam, then the side wall. The jet direction is chosen so that any impurities are blown out of the container with the main jet direction as far as possible.

The station S2 forms a system section in which a nozzle system is used to act on the interior of the station S1 pre-cleaned container is carried out with hot or dry steam, this steam having a temperature in the range of preferably 120 ° and being actively radiated into the inner area in such a way that the entire inner surface of the inner area presents itself as a beam-deflecting impact surface.

In the station S2 the container is acted upon with steam in a position in which the inner bottom of the container is inclined, in particular is inclined to such an extent that any condensate on the inner surface of the side wall can drain downwards. The container is fixed during the application of steam.

In the station S3 the container arriving there is shaken and blown over with a sharp stream of dry air. The drying is supported by the shaking effect, kinetic air flow effects, the drying effect of the air and the inherent heat of the container.

The transport of the containers through the system and thereby through the stations S1 ... S4 takes place through a transport system, the containers are in the stations S1 , S2 , S3 held and guided in such a way that they maintain a required treatment position due to the respective exposure to water, steam and dry air. The loading of the system can be done manually at the entrance of the same. The lock S4 is preferably located in a transition area to a clean room. The containers moving out of the system there can be stacked manually or by a handling system for further use, or they can be brought directly to a goods loading area.

Claims (13)

Process for sanitizing and drying washable, in particular box-like goods containers, in which: - As part of the preparatory process steps, thorough cleaning is carried out until the goods containers are visually clean, and - As part of a subsequent process step, at least the interior of the goods container is exposed to steam, - This steam is applied via a nozzle system to the inner wall of the respective container to be treated, and - This steam application is accomplished in such a way that at least with regard to the inner wall of the container, steam is applied over the entire surface of the same with deflection of the jet. Procedure according to Claim 1 , characterized in that after the application of steam, there is a shaking / vibration and / or suction of condensed steam and the residual water from the container. Procedure according to Claim 2 , characterized in that the suction volume and the steam application volume are coordinated with one another in such a way that the smallest possible amount of ambient air flow into the interior of the container takes place. Method according to at least one of the Claims 1 until 3 , characterized in that the steam has a temperature of at least 120 °. Method according to at least one of the Claims 1 until 3 , characterized in that the steam has a temperature of at least 150 °, preferably 180 °. Method according to at least one of the Claims 1 until 5 , characterized in that the steam has a pressure of at least 2 bar, in particular 8 bar. Method according to at least one of the Claims 1 until 6th , characterized in that the nozzle system and the container are moved against each other. Procedure according to Claim 7 , characterized in that the course of the path is coordinated in such a way that a cleaning front sweeps over and wanders over the inner surface of the container results. Method according to at least one of the Claims 1 until 8th , characterized in that the steam input is coordinated in such a way that the wall of the container is heated, which promotes self-drying of the container. Method according to at least one of the Claims 1 until 9 , characterized in that the superheated steam is generated by a heated nozzle system or a heat exchanger system directly upstream of the nozzle system. Device for carrying out the method according to at least one of the Claims 1 until 10 , with a nozzle system for applying hot or dry steam to the inner area of a pre-cleaned container, this steam having a temperature of at least 120 ° and being actively radiated into the inner area in such a way that the entire inner area of the inner area is at least successively swept over as a beam-deflecting impact surface . Device according to Claim 11 , characterized in that the container is acted upon with steam in a position in which the inner bottom of the container is inclined, in particular is inclined to such an extent that any condensate on the inner surface of the side wall can drain downwards. Device according to Claim 11 or 12th characterized in that the adhesive residual water droplets on the inside and outside of the container are largely shaken off or shaken off by means of two opposing compressed air piston vibrators - attached in a "stainless steel vibrating cage", whereby preferably the vibration (sinusoidal oscillation) can be regulated and is generated by freely oscillating, self-reversing pistons which produce a linear oscillation behavior.

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