DE102017215200B4 - Evaporator with a meandering flow channel system - Google Patents

Abstract

An evaporator for the evaporation of a liquid or an aerosol, comprising a thermally conductive flow body with an internal heat source and a flow channel system surrounding the heat source, the flow channel system being a meandering tube system which is meandering around the internal heat source so that the heat input in the tube system along the Flow path is increased, wherein the heat-conducting flow body comprises an inner body and an outer body surrounding the inner body and at least liquid-tight in the operating state, the flow channel system comprising outer pipe sections, the walls of which are formed proportionally by the inner body and the outer body.

Description

Field of invention

The invention relates to an evaporator for evaporating a liquid or an aerosol and to the use of the evaporator according to the invention for sterilization or decontamination. The invention also relates to a steam sterilization system containing an evaporator and a displacement body.

Background of the invention

The present invention relates to a device for the purposes of sterilization and decontamination. It is preferred for use in connection with the evaporation of a hydrogen peroxide-air aerosol and in particular for the sterilization of packaging before filling. It should be noted that the vaporizer according to the invention can also be used for entirely different purposes, provided that it is not subject to any restriction with regard to the liquid or the aerosol used.

Packaging in the pharmaceutical or food sector must be sterilized before being filled. For this purpose, the use of hydrogen peroxide has established itself in industry, which, because of its ability to form free radicals and its strong oxidative effect, has a very high rate of destruction for the entire spectrum of microorganisms.

An aqueous solution with hydrogen peroxide (usual concentrations between 10 and 50% by weight) is used for this. This is fed to a sterile stream of carrier air (particle-free air stream filtered through a particulate filter) mostly via a two-substance nozzle as finely atomized microdrops. The resulting aerosol is introduced into an evaporator heated to> 200 ° C, where it is converted into the gas phase and brought to the site of action.

Since hydrogen peroxide tends to break down into water and oxygen when exposed to light and heat, especially in highly concentrated solutions, when it comes into contact with metal surfaces, the challenge is to maintain an almost constant concentration of the mixture until it reaches the site of action.

In order to contain the catalytic decomposition, stabilizers are added to commercially available hydrogen peroxide solutions, which lead to severe contamination of the previously used evaporators. This makes time-consuming and costly maintenance and cleaning processes necessary.

Furthermore, the process requires a constant steam quality without the formation of droplets or condensate, since otherwise the product to be treated could be contaminated with hydrogen peroxide in an inadmissible manner.

The EP 1 738 777 A2 relates to an evaporator for a sterilization system and teaches in 10 an evaporator chamber in which the baffles effect a reciprocal deflection of the fluid flow. These baffles only serve to enlarge the surface in the homogeneously heated evaporator. With this channel arrangement there is a risk of sudden evaporation (so-called “flash evaporation”) and with this configuration the steam tends to condense within the evaporator. As a countermeasure, EP'177 proposes controlling the temperature of the outer walls and the guide plates (Paragraph [0046]), which requires a complex and correspondingly expensive equipment expansion.

The DE 26 39 301 A11 relates to a liquid evaporator for the generation of toxic vapors. She teaches a heatable thermally insulated container 1 that up to the height 9 is filled with a liquid flowing through the heating cartridge 10 is heated. Via the supply line 4th the liquid to be evaporated enters the coil 2 introduced, in which the evaporation takes place as a tube coil evaporator with heat input. There is no pipe system in the D1 that would cause a change in the heat input. In addition, there is no flow body which consists of an inner body with an outer body encompassing a liquid-tight seal, the flow channel system comprising pipe sections on the outside, the walls of which are partially formed by the inner body and the outer body. DE'301 teaches only conventional pipelines that run through the liquid-filled container 1 be guided.

The DE 195 00 421 A1 relates to a high-performance capillary heat exchanger for the sterilization of liquids. For this purpose, liquids are gently heated (ie in fractions of a second) and then cooled down again (see column 6th , Row 57-61 ). No evaporation of the liquid is disclosed in the entire DE'421 A1.

The DE 16 42 115 A relates to a device for the sterilization of devices. She teaches a steam line that expands to a cylindrical cooler surrounded by a double jacket. It deals with the throttling and cooling of the steam, a special evaporator is not disclosed in DE'115.

There is therefore a need for effectively working evaporators for liquids and Aerosols and especially in the area of H ₂ O ₂ steam sterilization.

Summary of the invention

It is an object of the present invention to provide an improved vaporizer for liquids or aerosols.

According to the invention, the object is achieved by an evaporator according to claim 1. Specific embodiments of the invention are the subject of the additional dependent or independent claims.

According to a first aspect of the invention, a vaporizer for vaporizing a liquid or an aerosol is provided, which comprises a heat-conducting flow body with an internal heat source and a flow channel system surrounding the heat source, the flow channel system being a meandering tube system that surrounds the internal heat source is performed so that the heat input in the pipe system is increased along the flow path.

The auxiliary device according to the invention has numerous advantages over the auxiliary devices known from the prior art.

As the inventors have found, the flow pipe routing according to the invention achieves controlled evaporation with increasing heat input, so that the critical phenomenon of sudden evaporation (known in the extreme case as a water vapor explosion) is effectively prevented.

The evaporator according to the invention thus provides homogeneous evaporation over the entire flow body.

The meandering pipe system effectively prevents the formation of condensate or droplets. This avoids the Leidenfrost effect, which often occurs with evaporators with a helix channel system.

Due to the meandering pipe routing with an internal heat source, a small design can be achieved, which is particularly advantageous when used in the packaging industry. The vaporizer can thus be easily and space-savingly integrated into a filling system and thus enables sterile steam to be generated at the site of action. This is a considerable advantage, especially with the high throughput of modern filling machines, since here the evaporator can be lowered onto the packaging that has passed by and raised again after disinfection has taken place.

The evaporator according to the invention can be used widely insofar as it is suitable for the evaporation of liquids and also aerosols.

Thanks to the internal heat source, the thermal energy is used particularly effectively, which on the one hand means energy savings and on the other hand prevents unnecessary or even harmful heating of the environment.

This enables a high rate of steam generation, with a highly concentrated, i. steam close to the saturation point can be generated.

With its compact and simple design, the evaporator can be manufactured in a simple manner and also inexpensively.

The evaporator according to the invention can be integrated into the already established packaging systems without additional effort. With its scalable design, the evaporator can also be easily adapted to a wide variety of process parameters.

In summary, the evaporator according to the invention allows optimized evaporation under controlled conditions with energy-efficient use.

The invention in detail

According to the invention, the evaporator comprises a flow body with an internal heat source and a flow channel system surrounding the heat source. The individual tubes of the flow channel system are thus led around the internal heat source.

According to the invention, the flow channel system is a meandering tube system. In the context of the invention, this is to be understood as a pipe system which undergoes a multiple change in direction, which leads to pipe sections running essentially parallel with a reverse flow change. In the case of a cylindrical flow body, this is preferably achieved by tube sections running longitudinally (i.e. parallel to the cylinder axis), which are connected at the ends of the cylinder by cross tubes.

According to the claim, the meandering tube system is guided around the internal heat source in such a way that the heat input in the tube system is increased along the flow path. The increase in the heat input according to the invention refers to the flow path as a whole. This means that the increase in the heat input via the flow path must take place essentially continuously. Successive pipe sections can also have the same heat input, or, in the case of short transverse pipes, there can be an increased heat input, which is again somewhat lower in the subsequent longitudinal pipe.

According to the invention, the pipe sections of the pipe system that are essential for the pipe length thus have at least no reduction in the heat input along the flow path.

In a preferred embodiment of the invention, two adjacent pipe sections oriented longitudinally have an essentially identical heat input.

According to the invention, the increasing heat input generated by the internal heat source can be generated by the most varied of means.

Thus, in a preferred embodiment, the pipe sections along the flow path can be brought ever closer to the internal heat source and thus have an increased heat input in a simple manner. In a particularly preferred manner, this involves a paired approximation of the longitudinal tube sections of the tube system that are essential for the introduction of heat.

As an alternative to this or in combination with the aforementioned method, the heat source can be separated from the corresponding pipe section by means of insulation of different design. In the case of a massive cylinder as a flow body, for example, holes or slots on the longitudinal side can be introduced which are provided with an insulator such as gas or foam.

According to the invention, the heat-conducting flow body of the evaporator comprises an inner body and an outer body which surrounds the inner body and closes off at least in a liquid-tight manner in the operating state. With this flow body made up of two basic components, the tube system according to the invention can be designed in a particularly simple manner.

Here, the flow channel system expediently comprises pipe sections on the outside, the walls of which are formed proportionally by the inner body and the outer body. According to the invention, an “outside pipe section” is to be understood as a pipe section which is formed on the outside of the inner body. Correspondingly, these pipe sections on the outside can be machined out of the inner body in a simple manner (for example by means of erosive manufacturing processes such as milling).

In a particularly preferred manner, the outer body is designed as an outer jacket. As the outer jacket, it has a significantly smaller thickness than the inner body and preferably has a thickness between 0.1 mm and 50 mm, particularly preferably between 0.2 and 25 mm and in particular between 0.5 and 20 mm.

In one embodiment, the outer body is detachably connected to the inner body, so that it can be separated from the inner body again in a non-destructive manner by reversing the connection process. As a result, the pipe sections are easily accessible from the outside and can accordingly be easily cleaned.

In a preferred embodiment, the connection of the bodies is established in that the inner body has a higher coefficient of thermal expansion than the outer body, so that the inner body and the outer body form a sealed interference fit in the operating state. The interference fit has the advantage that the connection does not require any additional connection means such as adhesives and guarantees tightness at operating temperature in a simple and reproducible manner.

In a particularly preferred manner, these two bodies are dimensioned so that they can be easily separated at room temperature. This means that in the case of a cylindrical outer body or outer jacket, its inner diameter is slightly larger than the outer diameter of the likewise cylindrical inner body. As a result, the two bodies can be easily detached from one another at room temperature and cleaned or replaced individually. After reassembly and heating by the internal heat source, the interference fit is restored and the evaporator is ready for use again.

In an alternative embodiment, the interference fit must be cooled below room temperature (for example to 5 ° C. or 0 ° C.) in order to detach the two bodies from one another.

• In einer Ausführungsform können die Rohrabschnitte, bzw. deren Wände durch innenseitige längliche Vertiefungen am Außenkörper in Verbindung mit der glatten Außenwand des Innenkörpers gebildet werden. Dies hat den Vorteil, dass der Innenkörper sehr einfach aufgebaut ist und lediglich der Außenkörper mit seinen, das außenseitige Rohrabschnittssystem definierenden Vertiefungen, entsprechend komplexer aufgebaut ist. Diese Ausführungsform bietet zudem die Möglichkeit, dass Außenkörper mit unterschiedlicher Rohrgestaltung bereitgestellt werden können, die dann je nach Anwendungszweck mit dem einheitlichen Innenkörper kombiniert werden können. So kann für eine Flüssigkeitsverdampfung (im Gegensatz zu einer Aerosolverdampfung) der Außenkörper Vertiefungen aufweisen, die ein über den Strömungsweg hin sich erweiterndes Rohrsystem aufbauen, um so die verdampfungsassoziierte Volumenerhöhung zu berücksichtigen.

Insofar as the flow body is formed in one embodiment by an inner body and an outer body, there are several options for designing the outer pipe sections of the evaporator, for example by one of the following embodiments:

• In one embodiment, the pipe sections or their walls can be formed by elongated recesses on the inside on the outer body in connection with the smooth outer wall of the inner body. This has the advantage that the inner body has a very simple structure and only the outer body with its depressions defining the outer pipe section system is correspondingly more complex. This embodiment also offers the possibility that outer bodies can be provided with different tube designs, which can then be combined with the uniform inner body depending on the application. For example, for liquid evaporation (as opposed to aerosol evaporation), the outer body can have depressions which build up a pipe system that widens along the flow path in order to take into account the increase in volume associated with evaporation.

In an alternative embodiment, the pipe sections can be formed by elongated depressions on the outside on the inner body and matching elongated depressions on the inside on the outer body. These preferably form the two halves of the pipe cross-section and thus define the pipe sections. This is particularly advantageous in connection with the interference fit. For example, the body on the outside could define various pipe systems which can then be brought into congruence with the pipe sections of the inner body by rotating the cylindrical outer body. In this way, a multifunctional evaporator can be implemented with only one inner and outer body.

In a preferred embodiment, the pipe sections are formed by elongated depressions on the outside on the inner body in combination with the smooth inner wall of the outer body. This variant is particularly simple and inexpensive to manufacture, since only the cylindrical inner body has to be reworked, which can be easily carried out by external milling for the pipe sections and drilling for the cross pipes.

In a preferred embodiment, the pipe sections on the outside have an approximately semicircular cross-section, the semicircle pointing inwards, i.e. is directed towards the heat source. In this form, increased heat input is possible on the inner longitudinal side. Ideally, the channel shape would have a large surface on the inside in order to have the largest possible contact surface with the aerosol or vapor. Such a shape can also be produced in a simple manner by machining, it being possible for channels to be formed as elongated holes.

In a further embodiment of the invention, the flow body and / or the inner body is a solid body. Both bodies, both the inner body and the outer body, are preferably designed as a solid body. A configuration of the inner body as a solid circular cylinder is particularly advantageous here. In this form, starting from the heat source, a uniform temperature gradient is built up in the inner body and the different heat input can be defined in a simple manner by the distance between the tubes and the heat source.

In one embodiment of the invention, the internal heat source is an elongated, preferably rod-shaped heating element. As a result, a correspondingly homogeneous temperature gradient can be built up over the length of the rod.

Numerous configurations for a heat source are available to those skilled in the art. In a preferred manner, this is an electrically operated heating element, that is to say for example a heating coil through which current flows. Alternatively, the inner body can also be inductively heated by the heat source comprising a coil through which a high-frequency current flows and which generates an alternating magnetic field. In a further embodiment, the heat source can also be operated with other heat carriers, e.g. B. hot oil, or even by a combustion process (e.g. using oil or gas).

An electrically operated resistance heating element is particularly preferred as the heat source.

In the case of an electrically operated heat source, this preferably has a heating power of at least 1000 watts. A heating power of 2000 to 2500 watts and in particular 2200 watts is particularly preferred here.

In a preferred embodiment of the invention, the rod-shaped heating element of the evaporator runs parallel to the longitudinal axis of the flow body or inner body. As a result, as already explained above, a correspondingly longitudinally homogeneous temperature gradient is built up, which can then result in a different heat input in the pipe sections running longitudinally and thus parallel to the rod-shaped heating element, depending on the distance from the heating element.

In the preferred shape of the flow body or inner body as a circular cylinder, the rod-shaped heating element runs parallel to the longitudinal axis, but particularly preferably offset from the center of the circle. As a result, the pipe sections located on the outer jacket (the so-called "outside") have a different distance to the Heating element and thus receive a different heat input due to the simplest conceivable configuration, which can also be continuously adjusted accordingly through the continuously selectable distance.

In a further embodiment of the invention, the pipe sections on the outside run parallel to the longitudinal axis of the solid body. As already stated, this is particularly advantageous in the case of a circular cylinder with an internal heat source likewise running alongside.

In one embodiment of the invention, the pipe sections on the outside are connected to one another to form a continuous flow channel system by means of cross pipes on the outside and cross pipes guided through the flow body or inner body. The cross tubes are preferably designed in their course in a straight line, arched, quarter or semicircular, oval or in a combination of different geometric shapes.

In a preferred embodiment, the outer cross tubes are arcuate or semi-circular in their course.

In a likewise preferred embodiment, the transverse tubes guided through the flow body or inner body have a straight course.

The last-mentioned embodiments are combined in a special way. There are therefore curved or semicircular cross tubes on the outside and, in addition, straight cross tubes guided through the flow body or inner body.

In a further embodiment, the pipe sections on the outside have a uniform pipe cross section, which is preferably identical to the pipe cross section of the cross pipes on the outside, the cross pipes passing through the flow body or inner body being the same size or smaller in pipe cross section.

It is preferred here that the cross tubes guided through the flow body or inner body are smaller in tube cross section. Due to the constriction of the pipe starting from the outer pipe sections, the fluid velocity increases according to the Venturi effect in order to lose speed again when passing from the cross pipe into the wider outer pipe sections. This intermediate speed change favors the formation of a turbulent flow and thus prevents the formation of condensate or droplets.

According to the invention, the flow body or the inner body can be constructed from any thermally conductive material that is temperature-resistant, provided it can withstand an operating temperature of at least 200.degree. Due to its corresponding thermal conductivity, the material can transfer the heat from the internal heat source to the fluid flowing through the pipe system, be it liquid, aerosol or vapor.

The flow body or the inner body preferably consists of a material selected from the group comprising aluminum or an aluminum alloy, steel, copper, brass, glass and oxidic or non-oxidic ceramics or a combination of these materials, aluminum or an aluminum alloy being preferred is.

Aluminum and its alloys have a high thermal conductivity (75 - 235 W / (m • K)), can be protected against corrosion simply by passivation, and have a low specific weight with easy machinability.

According to the invention, the outer body, which is preferably an outer jacket, can be constructed from any heat-conducting material.

It is preferred here that the outer body consists of a highly thermally conductive material, so that on the one hand the flow channels do not have any cold areas from the outside (outer jacket) either (i.e. are also heated by the internal heating source), but on the other hand there is a thermal separation of the external pipe sections from one another allowed. Accordingly, a material with medium thermal conductivity is to be preferred over a material with high thermal conductivity for the outer body or the outer jacket.

The outer body or the outer jacket preferably consists of a material selected from the group comprising aluminum or aluminum alloy, stainless steel, copper, brass, glass and oxidic or non-oxidic ceramics or a combination of these materials, stainless steel being preferred.

With good thermal conductivity, stainless steel is an extremely corrosion-resistant material that is commercially available as a stainless steel tube in a wide range of diameter and jacket thickness. Because it has a lower coefficient of thermal expansion than aluminum, it is a preferred material for forming a corresponding interference fit.

In a further embodiment, the outer body, which is preferably an outer jacket, is surrounded by an insulating element. This insulating element is preferably a cylinder-shaped tube that is open on both sides and that surrounds the outer body or the outer jacket (preferably in a form-fitting manner).

In a preferred embodiment of the invention, the tube section functioning as an outlet tube runs parallel to the longitudinal axis of the flow body or inner body and has an angled end section on the outlet side for generating an eddy current. Through this “kink” on the outlet side in the course of the pipe, the flow emerging from the straight outside longitudinal pipe is converted into a helical vortex flow. As a result, the exiting flow has predominantly a velocity vector along the longitudinal axis of the flow body and a velocity vector in the tangential direction of the round outlet pipe. In a particularly preferred way, this end section has an arcuate course and is designed specifically as a quarter-circle arc.

In a further embodiment, the inner body, which is shaped as a circular cylinder, has a conical shape on the outlet side and is preferably surrounded in this area by the outer body, which has a conical shape on the inside, forming a conical gap. As a result, the steam emerging from the angled outlet is converted into a turbulent eddy.

In a particular embodiment of the invention, the outlet-side conical shape of the inner body has a mandrel-shaped central tip which is designed to protrude into an outlet pipe that can be attached below the evaporator. As a result, the circular vortex that arises in the cone gap is passed through the outlet pipe as a circular vortex via the mandrel-shaped central tip and occurs in this form on the surface to be treated.

The three embodiments mentioned above, namely kinked pipe outlet, conical gap and mandrel protruding into the pipe, serve to release the generated steam in a vortex flow, whereby good distribution and mixing as well as optimal flow conditions of the medium are achieved.

In a further embodiment, the outlet opening of the evaporator and / or the outlet pipe has a catalyst which comes into contact with the emerging steam and has the ability to at least partially convert the hydrogen peroxide contained in the steam into hydroxyl radicals. Catalysts for activating hydrogen peroxide are known to the person skilled in the art. These are preferably selected from the group comprising iridium, manganese oxide, palladium, platinum, rhodium or ruthenium or combinations or alloys thereof.

In a preferred embodiment, the evaporator according to the invention is set up for continuous or pulsed evaporation of a water-air aerosol and preferably an H ₂ O ₂ -air aerosol. In the case of an H ₂ O ₂ -containing aerosol, this means that the vaporizer must withstand a temperature of at least 350 ° C during operation, even in long-term use, and must also be inert to the chemically reactive H ₂ O ₂ .

In a second aspect, the invention relates to the use of the evaporator according to the invention for the sterilization or decontamination of rooms, surfaces or objects, and in particular in the food and pharmaceutical industries.

In the food and pharmaceutical industries, it is used in particular for the sterilization or decontamination of secondary or primary packaging. These can be, for example, ampoules, glass vessels, plastic bottles, plastic containers, blisters, coated aluminum foils or composite packaging.

In particular, use is provided for packaging jackets that are open on one or both sides. This packaging jacket is particularly suitable for producing packaging for food, and in particular for flowable food. The packaging material is preferably made of plastic or a composite packaging material, in particular a paper / plastic composite packaging material.

In a third aspect, the invention relates to a steam sterilization system containing an evaporator according to the invention.

1. (a) eine Dosiereinheit für H₂O₂,
2. (b) eine am Einlass des Verdampfers positionierte Zweistoffdüse zur Erzeugung eines Aerosols aus einem Trägergasstrom und einer wässrigen Lösung, die bevorzugt eine wässrige H₂O₂-Lösung ist,
3. (c) Mittel zur Luftzuführung und/oder Luftaufbereitung,
4. (d) eine Trocknungseinrichtung zur Trocknung des sterilisierten Gebindes, und
5. (e) ein H₂O₂-Sensor zur Prozesssteuerung oder -Überwachung, der in bevorzugter Weise am Verdampferausgang positioniert ist.

This steam sterilization system, which preferably works with an H ₂ O ₂ -containing steam, can optionally also contain one or more of the following components:

1. (a) a dosing unit for H ₂ O ₂ ,
2. (b) a two-substance nozzle positioned at the inlet of the evaporator for generating an aerosol from a carrier gas stream and an aqueous solution, which is preferably an aqueous H ₂ O ₂ solution,
3. (c) means for air supply and / or air treatment,
4. (d) a drying device for drying the sterilized container, and
5. (e) an H ₂ O ₂ sensor for process control or monitoring, which is preferably positioned at the evaporator outlet.

1. (a) einen herkömmlichen oder erfindungsgemäßen Verdampfer zur Verdampfung einer Flüssigkeit oder eines Aerosols mit einer optionalen, am Einlass des Verdampfers positionierten, Zweistoffdüse zur Erzeugung eines Aerosols aus einem Trägergasstrom und einer wässrigen Lösung, und
2. (b) einen auslassseitig vorgesehenen Verdrängungskörper, der nach Einführen in das Gebinde mindestens 50% des Innenvolumens des Gebindes ausfüllt und stirnseitig und/oder längsseitig Öffnungen für den Dampfaustritt aufweist,
3. (c) wobei der Verdrängungskörper bevorzugt zylinder- oder quaderförmig ist und/oder im oberen Bereich ein auskragendes Element zur Umlenkung des Dampfs auf die Außenseite des Gebindes aufweist.

In a fourth aspect, the invention provides a steam sterilization system for a package comprising:

1. (a) a conventional or inventive vaporizer for vaporizing a liquid or an aerosol with an optional two-fluid nozzle positioned at the inlet of the vaporizer for generating an aerosol from a carrier gas stream and an aqueous solution, and
2. (b) a displacement body provided on the outlet side which, after being inserted into the container, fills at least 50% of the internal volume of the container and has openings for the steam outlet on the front and / or longitudinal sides,
3. (c) wherein the displacement body is preferably cylindrical or cuboid and / or has a cantilevered element in the upper region for deflecting the steam to the outside of the container.

1. (a) eine zentral auf der Stirnseite angebrachte Austrittsöffnung,
2. (b) mehrere zentral auf der Stirnseite angebrachte Austrittsöffnungen, oder
3. (c) einen plattenförmigen Abschluss der Stirnseite mit darüber angebrachten Öffnungen an den vier Längsseiten des Verdrängungskörpers, wobei die abschließende Platte bevorzugt eine Vorrichtung zur seitlichen Ablenkung des Dampfes aufweist.

In one embodiment of the invention, the displacement body has one of the following outlet openings for the steam:

1. (a) an outlet opening centrally on the front side,
2. (b) several outlet openings located centrally on the end face, or
3. (c) a plate-shaped end of the end face with openings attached over it on the four longitudinal sides of the displacement body, the closing plate preferably having a device for the lateral deflection of the steam.

It is preferred here that the displacement body has a protruding element in the upper area for deflecting the steam to the outside of the container. In this way, the sterilizing steam can still be used after it has emerged from the inside of the container in order to also sterilize the outer wall of the container, at least in the upper part that is critical for filling and closure.

To divert the steam to the outside, the projecting element is partially or completely provided with downward-pointing deflection elements. These direct the steam, which is deflected laterally by the collar, downwards and thus onto the outside of the container.

In a likewise preferred embodiment, the displacement body has openings in its upper region or on the protruding element for discharging the steam. Excess sterilization steam can be absorbed through these openings and discharged from the environment. The steam removed can then be inactivated. This can be done, for example, by condensation, binding to a carrier or by chemical inactivation. This embodiment enables targeted removal of the reactive sterilization vapors close to the container. Notably, sterile steam emissions represent a significant problem in the packaging industry, which can be effectively reduced by the present embodiment.

In an alternative embodiment, the steam sterilization system additionally has a return system, with the aid of which the steam removed by means of the discharge openings is at least partially returned to the evaporator.

The unused part of the hydrogen peroxide, i.e. the part of the hydrogen peroxide that was not converted during the sterilization, is preferably withdrawn from the sterilization zone with the non-condensed water vapor and, if necessary, the sterile air. The corresponding gas mixture is then fed to the condenser in order to partially condense the hydrogen peroxide and the water vapor. The gas mixture is preferably cooled to a temperature between 35 ° C and 95 ° C in the condenser. The temperature can be selected depending on the desired concentration of hydrogen peroxide in the condensate and / or the recovery rate of the hydrogen peroxide. As the temperature rises, less hydrogen peroxide is recovered but a higher hydrogen peroxide concentration is achieved in the condensate.

In a particularly preferred embodiment, the steam sterilization system described above, which is characterized by the presence of the displacement body, is carried out in combination with the evaporator according to the invention.

According to a further aspect, a control device for controlling and / or regulating the evaporator according to the invention or a steam sterilization system containing this evaporator is provided. This control unit ensures the sterilization of containers in the manner described with a high level of operational reliability. The control device expediently comprises a computer program product which can be loaded directly into a storage unit and which comprises software sections with which the The method for controlling and / or regulating the evaporator or the steam sterilization system can be carried out when the computer program product is executed on a system according to the invention.

Definitions

According to the invention, an “aerosol” is to be understood as a heterogeneous mixture (dispersion) of solid or liquid suspended particles in a gas. Liquid suspended particles are preferably present, which are then converted into the gaseous state by the evaporator. Air is preferably used as the gas.

According to the invention, a “thermally conductive body” is understood to mean a body with a thermal conductivity of at least 0.5 W / (m. K) and preferably of at least 50 W / (m · K).

Embodiment

Example 1:

An inventive H ₂ O ₂ evaporator according to the 1 to 4th The inner body is made of aluminum and the outer casing is made of stainless steel. In general, this system is designed in such a way that H ₂ O ₂ concentrations of up to 12% by volume in the outlet flow and an outlet temperature of up to 330 ° C. can be achieved. With a length of 180 mm and an outer diameter of 60 mm, this evaporator can be at a maximum heating capacity of 2500 watts for a maximum flow of air from 5 m ³ / h, and a H ₂ O ₂ -Volumenstrom of 1.8 I / h, a H ₂ Generate an O ₂ output concentration of approx. 7% by volume.

Figure list

• 1 zeigt in A eine schematische Darstellung von zwei Seitenansichten des Verdampfers gemäß einer Ausführungsform. In B ist der außenseitige Rohrabschnitt im Querschnitt vergrößert dargestellt.
• 2 zeigt eine schematische Darstellung von zwei Seitenansichten des Innenkörpers des Verdampfers gemäß einer Ausführungsform mit schematischer Schnittdarstellung entlang der Achsen J-J und I-I.
• 3 zeigt links eine Ausführungsform des erfindungsgemäßen Verdampfers in Aufsicht von oben und unter Angabe der Schnittebene H-H. Rechts wird eine Schematische Schnittdarstellung entlang der Achse H-H gezeigt.
• 4 zeigt in der oberen Hälfte eine Ausführungsform des erfindungsgemäßen Verdampfers mit Zweistoffdüse in Aufsicht von oben mit Angabe der Schnittebenen F-F und K-K, die entsprechend in der unteren Hälfte als Schnittdarstellung wiedergegeben sind.
• 5 zeigt den erfindungsgemäßen Verdampfer mit Zweistoffdüse und H₂O₂-Sensor als Schematische Explosionszeichnung in perspektiven Darstellung (oben) oder in Seitenansicht (unten).
• 6 zeigt den erfindungsgemäßen Verdampfer mit Zweistoffdüse und H₂O₂-Sensor unter Entfernung einer Außenmantelhälfte in perspektiven Darstellung (links) oder in zwei Seitenansichten (rechte Hälfte).
• 7 zeigt eine schematische Querschnittsdarstellung des erfindungsgemäßen Verdampfers aus 4 mit einem trapezförmigen Verdrängungskörper.
• 8 zeigt eine schematische Querschnittsdarstellung des erfindungsgemäßen Verdampfers mit Verdrängungskörper aus 7, wobei der Verdampfer sich von rechts nach links auf das zu sterilisierende eimerförmige Gefäß absenkt.
• 9 zeigt schematisch als Querschnittsdarstellung (links) oder in perspektivischer Ansicht (rechts) den erfindungsgemäßen Verdampfer aus 4 mit einem kubischen Verdrängungskörper.
• 10 zeigt eine schematische Querschnittsdarstellung des erfindungsgemäßen Verdampfers mit Verdrängungskörper aus 9, wobei der Verdampfer sich von links nach rechts auf die zu sterilisierende, beidseitig geöffnete Verbundverpackung absenkt und unten austritt.
• 11 zeigt eine schematische Darstellung des mäandrierenden Röhrensystems als Volldarstellung durch Ausblenden des Strömungskörpers in diesem Bereich.

These and other aspects of the invention are shown in detail in the drawings as follows.

• 1 FIG. A shows a schematic representation of two side views of the evaporator according to an embodiment. In B, the outside pipe section is shown enlarged in cross section.
• 2 shows a schematic illustration of two side views of the inner body of the evaporator according to an embodiment with a schematic sectional illustration along the axes JJ and II.
• 3 shows on the left an embodiment of the evaporator according to the invention in a plan view from above and indicating the sectional plane HH. A schematic sectional view along the HH axis is shown on the right.
• 4th shows in the upper half an embodiment of the evaporator according to the invention with two-substance nozzle in a plan view from above with indication of the sectional planes FF and KK, which are correspondingly reproduced in the lower half as a sectional illustration.
• 5 shows the inventive evaporator with two-substance nozzle and H ₂ O ₂ sensor as a schematic exploded drawing in a perspective view (above) or in a side view (below).
• 6th shows the evaporator according to the invention with two-fluid nozzle and H ₂ O ₂ sensor with removal of an outer shell half in a perspective view (left) or in two side views (right half).
• 7th shows a schematic cross-sectional representation of the evaporator according to the invention from 4th with a trapezoidal displacement body.
• 8th shows a schematic cross-sectional view of the evaporator according to the invention with a displacement body from FIG 7th , with the vaporizer descending from right to left onto the bucket-shaped vessel to be sterilized.
• 9 shows the evaporator according to the invention schematically as a cross-sectional illustration (left) or in a perspective view (right) 4th with a cubic displacement body.
• 10 shows a schematic cross-sectional view of the evaporator according to the invention with a displacement body from FIG 9 , the vaporizer descends from left to right onto the composite packaging to be sterilized, opened on both sides, and exits below.
• 11 shows a schematic representation of the meandering tube system as a full representation by hiding the flow body in this area.

Detailed description of the images

1 FIG. A shows a schematic representation of two side views of the evaporator according to an embodiment. It's a vaporizer 1 with a cylindrical flow body 10 shown, which decentrally and parallel to the longitudinal axis has a rod-shaped heating element, with only the extension piece as the outer part 32 is visible. The evaporator is at the lower end via a mounting flange 41 with the outlet pipe 40 connected. A pipe section is flanged laterally and perpendicularly to the outlet pipe, with an H ₂ O ₂ sensor being positively inserted into this pipe section so that its distal end is in the outlet pipe 40 protrudes (see the Cross section in 3 ). In B is the cross section of an outside pipe section 23 shown how it results from milling in the inner body with a round milling head with an offset guide.

2 shows a schematic illustration of two side views of the inner body of the evaporator according to an embodiment with a schematic sectional illustration along the axes JJ and II. Here are the outer and longitudinal pipe sections 22nd seen through the semicircular outside cross tubes 24 and internal straight cross tubes 26th are connected to each other and thus a meandering tube system 20th form. The position of the internal cross tubes 26th and the outside pipe sections 22nd is illustrated by the two cross-sectional representations II and JJ.

3 shows on the left an embodiment of the evaporator according to the invention in a plan view from above and indicating the sectional plane HH, both the heating element and the two-substance nozzle are not shown, so that the round hole for the introduction of the heating element at the top and the inlet opening for the aerosol to be evaporated, or below the liquid to be evaporated can be seen. A schematic sectional view along the axis HH is shown on the right, in which the interference fit from the inner body 12th and outer jacket 14th with the outside pipe sections thus formed 22nd you can see. Due to the inclined cut of the circular cross tube running through the inner body 26th it impresses as an oval shape. The outer jacket is over a mounting flange 41 with the outlet pipe 40 connected, the flange 41 an internal ring groove 42 for receiving an elastic sealing element (z. B. a ring seal, not shown here). The outer jacket has an annular groove on its upper end face 42 for receiving an elastic sealing element (not shown here). In this way, the association of the inner body and outer jacket is sealed even before the heat-induced formation of an interference fit. A flanged cross tube is inserted into the outlet tube 40 protruding H ₂ O ₂ sensor 50 attached. The inner body 12th is designed conically 15 on the outlet side and from the inside conical outer jacket with the formation of the conical gap 17th surround. The cone 15th has a thorn-shaped central tip 16 that is centered in the outlet pipe 40 protrudes.

4th shows in the upper half an embodiment of the evaporator according to the invention with two-substance nozzle in a plan view from above with indication of the sectional planes F-F and KK, which are correspondingly reproduced in the lower half as a sectional illustration. It is the evaporator according to 3 , with the addition of the two-fluid nozzle 60 with its two inlet holes 62 for the substance supply is shown. In addition, the rod-shaped heating element is also with its outer part 32 and inner part 31 shown.

5 shows the inventive evaporator with two-substance nozzle and H ₂ O ₂ sensor as a schematic exploded drawing in a perspective view (above) or in a side view (below). The individual components here are the heating element with the inner part 31 and outer part 32 , the two-substance nozzle 60 with the holes for the fabric feed 62 , the inner body 12th , the outer jacket 14th and the outlet pipe 40 with the H ₂ O ₂ sensor 50 can be seen.

6th shows the evaporator according to the invention with two-substance nozzle and H ₂ O ₂ sensor with removal of an outer shell half in a perspective view (left) or in two side views (right half) with the two-substance nozzle 60 and the holes for the fabric feed 62 (only one of them visible), the rod-shaped heating element, the inner body with the conical end 15th and the spinous process 16 , the outer jacket 14th , the outlet pipe 40 into which the H ₂ O ₂ sensor protrudes.

7th FIG. 11 shows a schematic cross-sectional representation of the evaporator according to the invention from FIG 4th with a trapezoidal displacement body. In the case of the evaporator, the outer jacket is positively connected to an insulating tube 18th surrounded, which provides additional insulation from the interior of the filling system when the evaporator is used in the filling system. The evaporator has a displacement body on the outlet side 70 on, which has an outlet opening at the front 71 in which the outlet pipe of the evaporator 1 flows out. The displacement body has a protruding element at its upper end 75 with downward-pointing deflector elements to deflect the steam and a bell-shaped suction device 76 to remove the excess steam, the steam through the suction nozzle 77 is removed from the bell-shaped device. The bell-shaped suction device protrudes beyond the protruding element and can thus extract the steam more efficiently.

8th shows a schematic cross-sectional representation of the evaporator according to the invention with a displacement body from FIG 7th , the vaporizer moving from right to left on the bucket-shaped vessel to be sterilized 78 lowers. The displacement body is designed in such a way that when it is lowered there is a uniform distance between the displacement body outer wall and the inner wall of the container, so that a homogeneous vaporization with the sterilization steam takes place. The cantilevered element is lowered over the Container out and directs the steam from above over the outer wall of the vessel.

9 shows the evaporator according to the invention schematically as a cross-sectional representation (left) or in a perspective view (right) 4th with a cubic displacement body 70 . In the case of the evaporator, the outer jacket is positively connected to an insulating tube 18th surrounded, which provides additional insulation from the interior of the filling system when the evaporator is used in the filling system. The evaporator has a displacement body on the outlet side 70 on, the one at the front a plate 73 with a cone-shaped device 74 for lateral deflection of the steam emerging from the outlet pipe. The steam is then passed through the slot-shaped outlet openings attached along the length 72 steered on the four sides of the displacement body onto the item to be sterilized.

10 shows a schematic cross-sectional representation of the evaporator according to the invention with a displacement body from FIG 9 , with the vaporizer moving from left to right onto the composite packaging to be sterilized, which is open on both sides 79 is lowered and the composite packaging is decontaminated or sterilized on the inside with the release of steam when it passes through completely.

11 shows a schematic representation of the meandering tube system as a full representation by hiding the flow body in this area. This makes the exact course of the flow channel system clear. After the liquid or the aerosol has entered the flow body from above, three pipe sections on the outside are traversed in order to then be guided through an internal cross pipe to the opposite side of the inner body. After passing through two further outside pipe sections, the change of side takes place again through an inside transverse pipe, with the exit from the flow body at the end after four further outside pipe sections. The last tube section on the outside has an angled (here an arcuate) end section on the outlet side for generating an eddy current.

Further variants of the invention and their implementation result for the person skilled in the art from the preceding disclosure, the figures and the patent claims.

Terms such as “comprise”, “have”, “include”, “contain” and the like used in the patent claims do not exclude further elements or steps. The use of the indefinite article does not exclude a plurality. A single device can perform the functions of several units or devices mentioned in the patent claims. Reference signs given in the claims are not to be regarded as restrictions on the means and steps used.

List of reference symbols

1

Evaporator

10

Flow body

12

Inner body of the flow body

14th

Outer jacket of the flow body

15th

Conical design of the inner body on the outlet side

16

thorn-shaped central tip of the inner body

17th

conical gap between inner body and outer jacket

18th

Insulation tube

20th

Tube system

22nd

outside pipe section

23

outside pipe section in cross section

24

semicircular outside cross tube

26th

straight cross tube guided through the flow body

30th

Round hole to accommodate the rod-shaped heating element

31

Rod-shaped heating element in the flow body

32

External part of the rod-shaped heating element

33

Rod-shaped heating element

40

Outlet pipe

41

Mounting flange

42

Ring groove for receiving an elastic sealing element

50

H ₂ O ₂ sensor

60

Two-substance nozzle

62

Hole for supplying the substance into the two-substance nozzle

70

Displacement body

71

outlet opening of the displacement body attached to the end face

72

outlet opening of the displacement body attached to the longitudinal side

73

Final plate of the sinker

74

Device for lateral deflection of the steam

75

Cantilevered element for redirecting the steam

76

Bell-shaped suction device for removing the steam

77

Extraction nozzle for removing the steam

78

Bucket-shaped container

79

unsealed composite packaging (open top and bottom)

J

Upper horizontal section plane of the inner body

I.

Lower horizontal section plane of the inner body

H, F, K

Vertical sectional planes of the evaporator

Claims (19)

An evaporator for the evaporation of a liquid or an aerosol, comprising a thermally conductive flow body with an internal heat source and a flow channel system surrounding the heat source, the flow channel system being a meandering tube system which is meandering around the internal heat source so that the heat input in the tube system along the Flow path is increased, wherein the heat-conducting flow body comprises an inner body and an outer body surrounding the inner body and at least liquid-tight in the operating state, the flow channel system comprising outer pipe sections, the walls of which are formed proportionally by the inner body and the outer body. A vaporizer according to Claim 1 , characterized in that the outer body is designed as an outer jacket. Evaporator according to Claim 2 , characterized in that the inner body has a higher coefficient of thermal expansion than the outer body, so that the inner body and the outer body form a sealed interference fit in the operating state, these two bodies preferably being dimensioned so that they can be easily separated at room temperature. Evaporator according to Claim 2 or 3 , characterized in that these outside pipe sections are formed by one of the following variants: a. by elongated depressions on the outside on the inner body and smooth inner wall of the outer body, b. inside elongated depressions on the outer body and smooth outer wall of the inner body, c. Outer elongated recesses on the inner body and matching inner elongated recesses on the outer body, variant a) being preferred. Evaporator according to one of the preceding claims, characterized in that the flow body or the inner body is a solid body and preferably a solid circular cylinder. Evaporator according to one of the preceding claims, characterized in that the internal heat source is an elongated, preferably rod-shaped heating element. Evaporator according to Claim 6 , characterized in that the rod-shaped heating element runs parallel to the longitudinal axis of the flow body or inner body, which is preferably a circular cylinder, the rod-shaped heating element in the circular cylinder preferably running offset to the center of the circle. Evaporator according to one of the Claims 5 to 7th , characterized in that the outside pipe sections run parallel to the longitudinal axis of the solid body, which is preferably a circular cylinder. Evaporator according to one of the Claims 2 to 8th , characterized in that the outer pipe sections are connected to form a continuous flow channel system by outer cross pipes and cross pipes guided through the inner body, the cross pipes being straight, curved, quarter or semicircular, oval or a combination of different geometric shapes . Evaporator according to Claim 9 , characterized in that the pipe sections on the outside have a uniform pipe cross section which is preferably identical to the pipe cross section of the cross pipes on the outside, the cross pipes guided through the inner body being of the same size or preferably smaller in pipe cross section. Evaporator according to one of the preceding claims, characterized in that the flow body or the inner body consists of a material selected from the group comprising aluminum or an aluminum alloy, steel, copper, brass, glass and oxidic or non-oxidic ceramic or a combination made of these materials, aluminum or an aluminum alloy being preferred. Evaporator according to one of the Claims 2 to 11 , characterized in that the outer body consists of a material selected from the group comprising aluminum or aluminum alloy, stainless steel, copper, brass, glass and oxidic or non-oxidic ceramics or a combination of these materials, stainless steel being preferred. Evaporator according to one of the Claims 1 to 12th , characterized in that the pipe section functioning as an outlet pipe runs parallel to the longitudinal axis of the flow body or inner body, which is preferably a circular cylinder, and has an angled end section on the outlet side for generating an eddy current, this end section preferably having an arcuate course. Evaporator according to one of the Claims 2 to 12th , characterized in that the inner body, which is shaped as a circular cylinder, has a conical shape on the outlet side, and is preferably surrounded in this area by the outer body, which has a conical shape on the inside, with the formation of a conical gap. Evaporator according to Claim 14 , characterized in that the outlet-side conical shape of the inner body has a mandrel-shaped central tip which is designed to protrude into an outlet pipe that can be attached below the evaporator. Use of the vaporizer according to Claims 1 to 15th for the sterilization or decontamination of rooms, surfaces or objects, especially in the food and pharmaceutical industries. A steam sterilization system comprising an evaporator according to one of the Claims 1 to 15th . A steam sterilization system for a package comprising: a. an evaporator according to one of the Claims 1 to 15th , and b. a displacement body provided on the outlet side of the evaporator which, after being inserted into the container, fills at least 50% of the internal volume of the container and has openings for the steam outlet on the front and / or the longitudinal side. Steam sterilization system according to Claim 18 , characterized in that the displacement body has one of the following outlet openings for the steam: a. an outlet opening located centrally on the end face, b. several outlet openings placed centrally on the front side, c. a plate-shaped end of the end face with openings on the four long sides of the displacement body, the closing plate preferably having a device for lateral deflection of the steam, and the displacement body preferably having a cantilevered element in the upper area for deflecting the steam to the outside of the Has container and / or preferably the displacement body in its upper region or on the projecting element has openings for discharging the steam.

Images