DE102006036462A1 - Hydrogen peroxide evaporator for food packing sterilization assembly incorporates a fluid bed of induction-heated metal balls with catalyst - Google Patents

Abstract

A food packing sterilization assembly has a hydrogen peroxide evaporation chamber (2, 2') with a feed tube (3) for liquid H2O2, an inlet (4) for a carrier gas, and an outlet (5) for the gas mixture. The evaporator incorporates a solid particle bed (6) that is a good heat conductor and surrounded by an induction coil (10). The particle bed is one of metal spheres with a catalyst e.g. palladium and forming a vortex bed. The grid is made of a non-conductor and located over the evaporation chamber. The chamber consist of two or more sections that may be disassembled (12).

Description

The The invention relates to an evaporator for sterilizing agents, preferably Hydrogen peroxide, for the sterilization of filling machines and / or packs, with an evaporator chamber, a supply for liquid sterilant, a connection for the feeder a carrier gas. and a discharge opening for dispensing a mixture of carrier gas and evaporated sterilant.

Out In practice, corresponding evaporators are already known. In these the evaporator chamber is designed as a piece of pipe, which from the outside via a electrical heating can be tempered with a heating resistor and having in its interior one or more so-called spin bodies. The swirl body form with the inside of the pipe section helical flow channels and provide so opposite a plug flow for one better heat transfer between pipe piece and carrier gas. Furthermore, a uniform concentration distribution achieved the sterilant at the outlet of the evaporator.

The known evaporators are filling machines for bottling of food in containers assigned, wherein the containers are glass bottles, plastic bottles such as PET, metal cans or, preferably, multi-layer composite packages can act. Trays designed as multi-layer composite packages are in many versions as Flachgiebel- or Schräggiebelverbundpackungen known. You will find mainly in the field of liquid packaging in the Connection with cold, cold-sterile, Hot- and aseptic filling Use.

at such filling processes is usually first a sterilization of the filling machine and / or the package itself is necessary, including mainly a mixture of a carrier gas and a vaporized, watery Hydrogen peroxide solution is used.

The known evaporators have a number of disadvantages. So own they have a high thermal inertia and reach their operating temperature only slowly. Further, the evaporators costly to manufacture and only with increased effort to clean.

Of the Invention is therefore the object of the aforementioned and previously described in more detail To design evaporators and further educate, that from the Prior art known disadvantages can be reduced.

These Task is with an evaporator for sterilizing agent with the features of the preamble of claim 1 solved by that in the evaporator chamber a fixed bed of a conductive material is provided and that the evaporator chamber in the region of the fixed bed is at least partially enclosed by an induction coil.

The Induction coil is supplied with alternating current, preferably a corresponding power regulation is provided. The current-carrying Coil generates a magnetic field and induces in per se known Make a stream in the fixed bed. Since the fixed bed the induced current a resistance, it comes to warming of the fixed bed. The heat ultimately arises immediately and immediately in the fixed bed itself and does not need convective Heat transport and / or heat conduction be directed there.

The Fixed bed can basically any conductive, at operating temperature solid material such as a conductive plastic and, if necessary, additional, non-conductive Have materials. The conductive Component of the packed bed should also have a minimum resistance, at all to be heated to sufficiently high temperatures. The conductive Component should also make up a sufficient proportion of the fixed bed, with enough Heat for rapid evaporation arises. Thus the fixed bed cost-effective and resistant to the for the Evaporation is required temperatures, there is the fixed bed preferably completely or at least partially of metal. A purely metallic fixed bed is however basically prefers.

On swirler can completely be waived. On the one hand, the fixed bed can be designed that a high turbulence and thus a good heat transfer from the fixed bed to the transfer medium he follows. Furthermore, the fixed bed provides a large heated surface for heat transfer to disposal.

When transfer medium will be either air, sterilized air, nitrogen or another inert gas or gas mixture used.

at the evaporator can still liquid sterilant For example, be applied directly to the fixed bed. The fixed bed in this case preferably has a high heat capacity, so that the applied Sterilization agent in the shortest time Time, especially immediately, evaporated.

In addition to the advantageous properties in terms of heat transfer and evaporation of the sterilant, another advantage of the evaporator is that the evaporator is easy to clean. For cleaning, it is usually sufficient to remove the fixed bed and through a replace new one. The exchanged fixed bed can then be subjected to a separate cleaning and then reused. Longer downtimes can be avoided.

According to one Teaching the invention may be the fixed bed of a variety of solid particles be formed. This facilitates the cleaning of the fixed bed, as at a one-piece fixed bed and spaces between the same are cleaned have to.

Preferably are solid particles in spherical form whose uniform surface is particularly easy to clean. Furthermore, spherical solid particles allow without further the formation of uniform and therefore evenly flowed through fixed beds. In addition, such a high packing density and therefore a good heat transfer be achieved.

A Improvement of heat transfer will achieved according to another teaching of the invention characterized in that the Solid particles in a state of operation of the evaporator is a fluidized Form fluidized bed. The fixed bed then expands as a result of the carrier gas flow in a known manner and takes properties of a fluid at. Again, are spherical Solid particles preferred to the abrasion of the solid particles to reduce.

The Terms fixed bed and fluidized bed are not mutually exclusive in the present case, because the evaporator, even if in a working condition, a fluidized bed has, outside of operation (no carrier gas volume flow) has a fixed bed.

The Fixed bed can be easily inserted into the evaporator chamber and again be taken out when in the direction of gravity below the Fixed bed a grate element is provided, on which rests the fixed bed. The grate element is, for example, a mesh fabric, a perforated plate or similar. The openings of the grate element can circular or slotted and are smaller than the diameter of the solid particles.

The Grate element is preferably made of a non-conductive material manufactured. That way you can damage of the evaporator and the electrical components such as one for the power supply used HF generator safely avoided.

Around the heat input to increase and / or for a uniform heat distribution to ensure that the evaporator chamber on the Height of Fixed bed is enclosed by the induction coil.

Becomes operated the fixed bed as a fluidized bed, so it may also be appropriate when the evaporator chamber over the height of the fluidized bed is enclosed by the induction coil. In the fluidized bed can then, without further ado, a steady operating temperature be maintained.

To Another teaching of the invention is the supply of sterilizing agent, the Connection for the feeder of carrier gas and the delivery port for dispensing the mixture of sterilant and carrier gas, respectively a detachable one Associated with connection. This makes it easier to remove the evaporator possible and a contaminated fixed bed can readily against a purified Fixed bed to be replaced.

To Another embodiment of the invention provides that the Evaporator chamber formed as a separate component and with the remaining evaporator via detachable connections is connectable. Again, a simple exchange of the fixed bed possible. Furthermore, the evaporator chamber can be exchanged as such, if necessary.

to Reduction of heat loss and for one a simpler embodiment of the evaporator, the evaporator chamber from a non-conductive Be made of material. The evaporator chamber is not heated in this way. This Although it has a negative effect on the heat exchange available surface out. However, the fixed bed already provides a very large surface for the heat exchange to disposal. In addition, it leads to a more uniform temperature distribution in the evaporator chamber.

Further it may be preferred if the fixed bed at least partially a having catalytically active component resulting in a catalytic Implementation of the sterilant leads to radicals. Preferably In this way, hydrogen peroxide is reacted, with hydroxyl radicals get free. in principle can but also organic and inorganic peracids as well as comparable chemical Compounds come as sterilizing agents in question. The resulting Radicals are particular in terms of subsequent sterilization reactive and lead too for Man and machine harmless reaction products.

The catalytically active component may be palladium, iridium, rhodium, Rhutenium, manganese dioxide and / or an alloy of these.

following The invention is based on a merely preferred embodiments drawing closer explained. In the drawing show:

1 a first embodiment of an evaporator according to the invention in longitudinal section and

2 A second embodiment of an evaporator according to the invention in longitudinal section.

The 1 shows a first embodiment of an evaporator 1 which is essentially formed by a pipe section with a circular cross-section. He could also have a different cross section.

The evaporator 1 has an evaporator chamber 2 on, in which the actual evaporation of the sterilizing agent takes place. The sterilant is in liquid form via a side feed 3 fed. At the bottom of the illustrated evaporator 1 is a connection 4 for the supply of a carrier gas, while at the upper end of the evaporator 1 a discharge opening 5 is provided for delivery of the mixture of carrier gas and sterilant.

In the evaporator chamber 2 is a fixed bed 6 from individual spherical solid particles 7 provided on a grate element 8th rest and be flown from below with a carrier gas. Just below the fixed bed 6 ends the feeder 3 in a kind of nozzle element or atomizer element. The feeder is designed for the use of hydrogen peroxide.

Also if not shown in a separate illustration, can the feeder alternatively also protrude into the fixed bed. Then it comes for direct contact between the sterilant and the solid particles. Furthermore, if necessary, a Randgängigkeit be avoided. Is enough the feeder however, too far into the fixed bed, can at the bottom of the Fixed bed for the evaporation is relatively ineffective Form areas, which reduces the efficiency of the evaporator.

The supplied sterilizing agent also passes as a result of the carrier gas flow 9 in contact with the fixed bed, by one around the pipe section of the evaporator 1 arranged around induction coil 10 can be heated inductively. As a result of the contact between the still liquid supplied sterilant and the heated fixed bed 6 the sterilant evaporates almost spontaneously. The vaporized sterilant is then removed from the carrier gas flow 9 entrained and as a carrier gas / sterilant mixture from the discharge opening 5 discharged. From the discharge opening, said mixture is passed to the surfaces to be sterilized.

I'm in the 1 illustrated embodiment of an evaporator 1 is the induction coil 10 slightly spaced from the evaporator chamber 2 arranged. This is possible because a good thermal contact here between the evaporator chamber 2 and induction coil 10 is not important. Basically, the induction coil 10 but also in direct contact with the outer wall of the evaporator chamber 2 be arranged.

The discharge opening 5 , the feeder 3 and the connection 4 have detachable connections 11 . 11 ' . 11 '' in the form of flanges. However, other, known from the prior art, releasable connections could be provided.

Not the connections are shown for the carrier gas, the carrier gas / sterilant mixture and the sterilant. These can be done by a professional without further supplements and, if necessary, with a blower, a D storage or guiding elements are provided without here a further discussion would be required.

In the in the 2 illustrated embodiment of an evaporator 1' is the evaporator chamber 2 ' above and below with a detachable connection 12 . 12 ' provided in the form of flanges, so that instead of the entire evaporator 1 also only the evaporator chamber 2 ' together with the grate element 8th and the fixed bed 6 can be removed.

Furthermore, from the 2 it can be seen that the induction coil 10 ' also the evaporator chamber 2 ' far above the fixed bed 6 encloses. The diameter of the evaporator chamber 2 and the diameters of the spherical solid particles 7 are further so on each other and on a volume flow range of the carrier gas stream 9 coordinated that forms a fluidized bed or a fluidized bed in an operating condition - with a corresponding carrier gas volume flow. The fluidized bed then extends substantially to the upper end of the induction coil 10 ' ,

The carrier gas flow 9 must by no means always be directed from bottom to top, even if this is preferred in the illustrated embodiments. In principle, the carrier gas stream 9 also be directed from top to bottom, with the supply 3 for the sterilant above the packed bed 6 can end. Ultimately, however, are the arrangement of the feeder 3 for the sterilant and the direction of the carrier gas flow 9 independently and freely selectable.

It is also possible to use the evaporator 1 . 1' to operate in a recumbent position in which the evaporator chamber 2 . 2 ' and the carrier gas stream 9 ho run rizontal.

Claims (14)

Evaporator for sterilizing agent, preferably hydrogen peroxide, for the sterilization of filling machines and / or packages, with an evaporator chamber ( 2 . 2 ' ), a feeder ( 3 ) for liquid sterilant, a connector ( 4 ) for the supply of a carrier gas and a discharge opening ( 5 ) for dispensing a mixture of carrier gas and vaporized sterilizing agent, characterized in that in the evaporator chamber ( 2 . 2 ' ) a fixed bed having a conductive material ( 6 ) is provided and that the evaporator chamber ( 2 . 2 ' ) in the area of the fixed bed ( 6 ) at least partially from an induction coil ( 10 . 10 ' ) is enclosed. Evaporator according to claim 1, characterized in that that the fixed bed comprises a metallic material. Evaporator according to claim 1 or 2, characterized in that the fixed bed ( 6 ) of a plurality of separate solid particles ( 7 ) is formed. Evaporator according to claim 3, characterized in that the solid particles ( 7 ) are spherical. Evaporator according to claim 3 or 4, characterized in that the solid particles ( 7 ) in an operating state of the evaporator ( 1 . 1' ) are present as a fluidized bed. Evaporator according to one of claims 1 to 5, characterized in that the evaporator chamber ( 2 . 2 ' ) below the fixed bed a grate element ( 8th ) having. Evaporator according to one of Claims 1 to 6, characterized that the grate element consists of a non-conductive material. Evaporator according to one of claims 1 to 7, characterized in that the evaporator chamber ( 2 . 2 ' ) over the height of the fixed bed ( 6 ) from the induction coil ( 10 ) is enclosed. Vaporizer according to one of claims 5 to 7, characterized in that the evaporator chamber ( 2 . 2 ' ) over the height of the fluidized bed of the induction coil ( 10 ' ) is enclosed. Vaporizer according to one of claims 1 to 9, characterized in that the supply ( 3 ) for liquid sterilant, the connection ( 4 ) for the supply of the carrier gas and the discharge opening ( 5 ) for delivering the mixture of carrier gas and vaporized sterilizing agent in each case a detachable compound ( 11 . 11 ' . 11 '' ) assigned. Evaporator according to one of claims 1 to 9, characterized in that the evaporator chamber ( 2 ' ) as a separate component and with the remaining evaporator ( 1' ) via detachable connections ( 12 . 12 ' ) is formed connectable. Vaporizer according to one of claims 1 to 11, characterized in that the evaporator chamber ( 2 . 2 ' ) is made of a non-conductive material. Evaporator according to one of claims 1 to 12, characterized in that the fixed bed ( 6 ) has at least partially a leading to a catalytic conversion of the sterilizing agent, catalytically active component. Evaporator according to Claim 13, characterized that the catalytically active component palladium, iridium, rhodium, Rhutenium, manganese dioxide and / or an alloy of these is.