Patent Application
20120258023
The invention relates to a device for generating decontamination agent vapour, particularly hydrogen peroxide vapour, comprising an evaporator body, a heating unit for heating the evaporator body and a plurality of feed channels for feeding decontamination liquid to be evaporated, preferably a liquid containing hydrogen peroxide. The invention preferably relates to a so-called flash vapour generator (high-speed vapour generator). The invention further relates to a preferably pharmaceutics-based assembly comprising a space to be decontaminated, particularly an isolator and/or a lock, and a device for generating decontamination agent vapour.
Hydrogen peroxide vapour is used for the decontamination of isolators and/or locks in the pharmaceutical industry, due to its high reactivity. Hydrogen peroxide vapour is obtained by evaporating an aqueous hydrogen peroxide solution. To minimise the explosion risk during the evaporation of solutions containing hydrogen peroxide, so-called flash evaporators (flash vapour generators) are used, with the aim of the continuous, rapid (in a flash) evaporation of small quantities of liquid containing hydrogen peroxide. It is not permitted for larger quantities of liquid containing hydrogen peroxide to be boiled, due to the aforementioned explosion risk. The difficulty in evaporating small quantities of hydrogen peroxide-containing liquid, particularly aqueous solutions, is the formation of liquid droplets which “dance” on hot evaporator surfaces and impede efforts towards rapid evaporation.
A hydrogen peroxide vapour generator with a flat evaporator surface is known from DE 10 2006 006 095 A1. The aforementioned “dancing” droplet formation can take place here.
An alternative flash evaporator (high-speed evaporator) is known from EP 0 972 159 B1, which is characterised by evaporator channels disposed in an evaporator body in a hydraulically interconnecting manner. The design is comparatively complex.
In relation to the further state of the art, reference is made to DE 602 03 603 T2 or DE 603 00 820 T2.
A hydrogen peroxide evaporator with a pot-like housing and an evaporator body is known from DE 2005 030 822 A1, said evaporator having a single, large-scale evaporator surface, wherein heat is supplied to the decontamination agent only from below. The known evaporator seems to be in need of improvement in terms of its evaporation rate and also in relation to the avoidance of “dancing” decontamination agent droplets. It is further known from DE 2005 030 822 A1 for a plurality of evaporators to be connected via one line in each case to a vessel requiring sterilisation, in order to increase the amount of decontamination vapour. The total evaporator costs are therefore incurred x-times. In addition, a plurality of vapour lines must be conducted into the space to be evaporated, which is problematic in the case of small spaces for lack of space. In addition, a plurality of seals must then be provided.
A water evaporator is known from CN 2009 43844 Y. The known evaporator has an evaporator body with a plurality of small holes. A single feed channel is jointly assigned to these, said feed channel being disposed centrally above the evaporator body. So that the plurality of small holes can make their contribution to the evaporation, a sufficiently large quantity of liquid must be fed through the single feed channel, although this would then run counter to the goal of the spontaneous flash evaporation of decontamination agents. In practice, this would result in a hazardous boiling of decontamination agents. The known evaporator is not therefore suitable for evaporating decontamination agents.
All the aforementioned flash evaporators are characterised by a comparatively complex design and/or by an evaporation rate capable of improvement.
Based on the aforementioned state of the art, the problem addressed by the invention is that of indicating a flash evaporator (high-speed evaporator) with the simplest possible design to generate decontamination agent vapour, which is characterised by a high evaporation rate. The formation of “dancing” decontamination agent liquid droplets within the evaporator should preferably be largely avoided. Moreover, the problem involves indicating an assembly comprising a space to be decontaminated and a correspondingly improved vapour generator. This is preferably an assembly for decanting and/or processing pharmaceuticals.
In relation to the high-speed vapour generator, the problem is solved in the case of a generic device, in that a plurality of blind holes is provided in the one-part or multi-part evaporator body and the blind holes are each assigned at least one, preferably exclusively one, of the feed channels, in order to conduct the decontamination agent liquid to be evaporated via these, preferably in droplets. The decontamination liquid to be evaporated is preferably an aqueous solution of hydrogen peroxide, quite especially preferably a 35% to 50% solution.
In relation to the assembly, preferably a pharmaceutical assembly, the problem is solved through the use of a vapour generator designed as described earlier.
Advantageous developments of the invention are specified in the dependent claims. Included within the framework of the invention are all combinations of at least two features disclosed in the description, claims and/or figures. To avoid repetition, features disclosed with respect to the device should also be regarded as disclosed and claimable with respect to the method. Similarly, features disclosed with respect to the method should also be regarded as disclosed and claimable with respect to the device.
The invention is based on the knowledge that rapid evaporation of decontamination liquid fed preferably in droplets can be achieved in relation to the evaporation rate in an improved, simplified manner in that the evaporation takes place within (peripherally closed) blind holes in a one-part or multi-part evaporator body. This is due to, among other things, the fact that the heated peripheral wall of the blind holes is at a significantly smaller distance from the decontamination liquid fed for evaporation than a peripheral wall of a cylindrical evaporator with a level base area. In a high-speed evaporator designed according to the concept of the invention, a larger amount of heat can thereby be fed to the decontamination liquid to be evaporated, preferably fed in droplets, in the shortest possible time, namely not from below, but also through radiation heat from the peripheral wall of the corresponding blind hole. Through the provision of blind holes provided in an evaporator body (particularly an evaporator block), which may be produced as bores for example, an exceptionally simple and effective evaporator device design is achieved. Unlike in the case of evaporators known from the state of the art, it is not necessary to provide evaporator channels crossing the evaporator body, through which the liquid to be evaporated is conducted, wherein the aforementioned channels in the state of the art are also hydraulically interconnected in a costly manner. Quite particularly advantageous is an embodiment of the device for generating decontamination agent vapour, in which the preferably one-part evaporator body is formed from aluminium, particularly an aluminium alloy, to achieve optimum heat conduction. It is still further preferred for the heating unit to be designed and set such that it heats the evaporator body to a temperature within a temperature range of between roughly 100° C. and roughly 140° C. It is quite particularly preferable for the temperature to be around 120° C. or under during evaporator operation, so that the formation of closed, not suddenly evaporating droplets on the evaporator surface is optimally prevented. It is particularly advantageous for the maximum diameter of the blind holes preferably with cylindrical contours at least in section not to exceed a dimension of 50 mm. It is still further preferable for the maximum diameter to be 40 mm or under. It is quite particularly preferable for the diameter to be chosen from a range of values of between roughly 30 mm and 35 mm. Ideally, the maximum depth extension of the blind holes (closed at the bottom) is also limited and amounts to under 50 mm, quite particularly preferably under 40 mm, even more preferably under 30 mm. The depth extension as far as the base of the blind hole is preferably roughly 25 mm.
Particularly preferred is an embodiment in which the blind holes do not have a circular contour, but a rectangular one, particularly, at least approximately, square, wherein it is still further preferred for the blind holes to have no sharp edges, but edges exhibiting a radius, i.e. rounded. This embodiment seems rare at first sight, as blind holes with rectangular contours are comparatively expensive to produce compared with blind holes with circular contours, particularly due to the milling. Surprisingly optimised evaporation properties can be achieved, however, through the rectangular contour (two pairs of parallel sides disposed at right angles), preferably with rounded corners.
It is particularly advantageous for the length to width ratio of the blind holes to be roughly 1 to roughly 1.3, particularly preferably roughly 1.1. In a quite particularly preferred embodiment, the length of each blind hole (measured towards the longitudinal extension of the evaporator) is roughly 27.75 mm and (the width extending perpendicularly thereto) is roughly 25 mm. Particularly preferably, the depth of the blind holes with a rectangular contour is roughly 24 mm. In other words, the ratio between the length, width and depth is approximately 1:1:1. It has proved particularly advantageous for blind holes with a rectangular contour to be disposed in a row. Quite particularly preferably, six identical blind holes are disposed in a row, i.e. behind one another in the longitudinal extension of the evaporator, wherein two adjacent blind holes in each case are spaced from one another by fewer than 10 mm, quiet particularly preferably by roughly 4 mm.
The number of blind holes provided and/or to be supplied with decontamination liquid to be evaporated at the active agent concentration to be reached in the carrier air and/or in the atmosphere of the space to be decontaminated is adapted and adjusted in this manner.
In accordance with the invention at least one, preferably exclusively one feed channel in each case, is allocated to each of the blind holes for the feeding of decontamination agents to be evaporated, particularly in droplets—this means that the feed channels are disposed such that the decontamination agent to be evaporated can be fed straight into the blind holes, preferably dropped into these.
There are different possibilities with regard to the geometric design of the blind holes. Quite particularly preferably, these have a cylindrical casing surface, preferably coupled with a circular base surface. Alternatively, the blind holes may have a cylindrical casing surface coupled with a conical base section.
As previously explained, the blind holes are rectangular according to an alternative embodiment, particularly with an at least approximately square contour, wherein it is still further preferable for the edges running in an upright direction (viewed in the peripheral direction) to be rounded, for example, preferably with a curvature radius of roughly R=5 mm.
In accordance with an alternative embodiment, the diameter of the cross-sectional surface of the blind holes, which preferably have a circular contour, diminishes as the distance from their upper inlet opening increases, alternatively stepped or continuously, for example, conically.
It is particularly preferable for all blind holes to be identically formed.
In a further development of the invention, it is advantageously provided that the blind holes are not immediately adjacent to one another, but are spaced apart from one another, particularly in order thereby to guarantee a uniform heat supply. The blind holes are preferably not hydraulically interconnected directly, via cross-bores for example.
There are also different possibilities with regard to the specific embodiment of the evaporator body. Evaporator bodies known in the art usually have a cylindrical contour. An embodiment in which the evaporator body of the device proposed here for generating decontamination agent vapour has a greater length extension than the width extension and preferably also a greater length extension than the depth extension is preferred. It is quite particularly advantageous for the evaporator body to have at least approximately square contours at least in sections.
There are also different possibilities with regard to the arrangement of the blind holes. An embodiment is preferred in which at least one, preferably exclusively one, row of blind holes extending in the direction of the longitudinal extension of the evaporator body is provided. An embodiment with a plurality of particularly parallel rows can also be achieved.
The heating unit is preferably designed and disposed in such a manner that it extends along the longitudinal sides, i.e. along the longitudinal extension of the evaporator body. It preferably also extends in addition along the base surface. It is quite particularly advantageous where two, particularly parallel, rows of blind holes are provided, if the heating unit extends into an area between the rows, so that a uniform supply of heat to the blind holes can thereby be guaranteed. The heating unit is preferably an electrical resistance heater. A temperature sensor, for example a PT 100, is advantageously included in the evaporator body. The temperature sensor, particularly the PT 100, is preferably used to monitor and record the temperature and the temperature course. Quite particularly preferred in addition to or as an alternative to the temperature sensor, a thermocouple assigned to the heating device is provided. The heating unit is ideally at least a heating rod, which is preferably contained in an opening, particularly a bore, running in the direction of the evaporator's longitudinal extension. The thermocouple is also preferably disposed in this opening, preferably integrally with the heating rod. It is still further preferred for a plurality of heating rods, particularly disposed in parallel, to be provided. Good results were obtained with a total of three heating rods, wherein the three heating rods are preferably controlled by means of a joint thermocouple, which is yet further preferably located in a central bore or opening along with the central heating rod. The use of a total of only two heating rods disposed symmetrically relative to a perpendicular mirror plane is particularly preferred.
To prevent the decontamination liquid conducted through the feed channels from being entrained by carrier air before the liquid is evaporated, provision is advantageously made in a development of the invention for the feed channels to penetrate the inlet openings of the blind holes, in other words to project into the blind holes. It is quite particularly preferred in this case for the preferably dry and heated carrier air to flow over the blind holes and thereby entrain the decontamination agent vapour rising from the blind holes.
It may be that in practice the feed channels become encrusted or are subject to wear. To avoid major repair work, it is therefore advantageously provided in a development of the invention that the feed channels through which the decontamination liquid to be evaporated is conducted to the blind holes, preferably in droplets, to the blind holes, are replaceable, i.e. designed and disposed in an interchangeable manner. Surprisingly, for the formation of the feed channels, injection needles available in bulk and particularly made of stainless steel can be used for this. Said needles are preferably provided with a Luer-Lock connection fitting at their upper ends facing away from the blind holes, via which replaceability and interchangeability can be guaranteed. Particularly preferably, the internal diameter of the feed channels is chosen from a value range of between roughly 0.5 mm and roughly 2 mm.
The feed channels formed particularly by injection needles are preferably disposed in such a way that they supply decontamination liquid to be evaporated to the blind holes from a distributor chamber, so in other words they represent the hydraulic connection between the distributor chamber and the blind hole in each case. For this purpose, the feed channels preferably project into a flow channel for carrier air disposed above the blind holes and therefore above the evaporator body or else they are disposed in said flow channel or preferably penetrate it up to and into the blind holes, in order to prevent an entrainment of as yet unevaporated decontamination liquid with the carrier air, as already described.
An embodiment in which the decontamination liquid to be evaporated can flow to the feed channels via a supply channel in each case is particularly advantageous. Ideally, these supply channels are not flexible lines, but channels introduced into, particularly milled into, a metallic evaporator component. The supply channels are ideally inserted in a cover plate and connect a particularly central supply line to the feed channels. In order to guarantee that the feed channels are each supplied with the same quantity of decontamination agent to be evaporated, a development of the invention advantageously provides that the channels—based on an equal flow cross-section—are equally long, so that the liquid to be evaporated encounters the same flow resistance. The aforementioned supply channels are ideally supplied via a clocked metering pump, particularly disposed outside the actual evaporator. It is particularly advantageous for the supply channels to emerge from one, preferably central, space, which still further preferably is introduced as a recess in the cover plate with the supply channels. The supply channels may be sealed by a joint closing plate, for example, which can be secured to the cover plate by screws, for instance. In addition or alternatively, the supply channels may be sealed on their upper side by metal plates, particularly stainless steel plates, wherein said plates are preferably welded to the cover plate exhibiting the supply channels.
It is particularly advantageous if the flow volume of decontamination liquid to be evaporated can be set for the individual feed channels. In other words, it is preferable for at least some of the feed channels to be assigned a setting mechanism with which the flow volume that is to flow through the feed channel can be set. These setting mechanisms are preferably located within or close to the aforementioned distributor chamber, into which decontamination liquid to be evaporated can preferably be pumped from a store, particularly an interchangeable storage bottle.
The invention also relates to an assembly, particularly a pharmaceutical assembly, comprising a space to be decontaminated with decontamination agent vapour, particularly an isolator and/or a lock, and also a device designed as described earlier for generating decontamination agent vapour, particularly hydrogen peroxide vapour.
In the state of the art, high-speed evaporators are customarily disposed in such a manner that they are supplied with air from the space being decontaminated as carrier air and the carrier air enriched with hydrogen peroxide is released straight back into the space to be decontaminated. This usually leads to condensation of hydrogen peroxide in the space being decontaminated. Condensation of this kind should be prevented wherever possible in developments of the invention, which can be advantageously supported or achieved in that the high-speed evaporator is not, or not exclusively, supplied with carrier air from the space to be decontaminated, but with fresh air. Fresh air does not only mean preferably dry ambient air (particularly<10% relative atmospheric humidity), but also compressed air from corresponding storage vessels, particularly pressure cylinders. It is essential that this is not air fed from the space to be decontaminated. This requires air also to be continuously delivered from the space to be decontaminated into the environment, for example, in order to prevent inadmissible overpressures. The advantage of an assembly of this kind is the improved controllability of the hydrogen peroxide concentration in the ambient air of the space to be decontaminated and better pressure controllability during decontamination. The pressure in the space should be above ambient pressure during decontamination, preferably around 30 Pa above it. In relation to the specific configuration of the evaporator, there are two different possibilities here. The evaporator may, for example, be connected to the single fresh air supply line (carrier air supply line), so that all the air to be fed into the space to be decontaminated flows straight through the evaporator. It is preferable for the evaporator to be arranged in this way, if the fresh air supply does not exceed 80 m3 per hour during operation of the space to be decontaminated, particularly an isolator. In an alternative assembly, a bypass line is allocated to the preferably single fresh air line (supply line) disposed in the flow direction upstream of the evaporator, the evaporator being connected to said bypass line—this results in part of the fresh air supplied not passing directly through the evaporator, but preferably being mixed with the diverted enriched carrier air passing through the evaporator before it reaches the space to be decontaminated. An assembly of this kind is particularly appropriate when the space to be decontaminated is in operation, i.e. following decontamination of a fresh air supply of over 80 m3 per hour.
To set or control the decontamination agent vapour concentration in the carrier air, it is preferable for a regulation line to discharge into an intermediate or connection line downstream of the evaporator, through which an adjustable volume of air, particularly of fresh air, can be mixed to dilute the vapour concentration in the carrier air.
Further advantages, features and details of the invention emerge from the following description of preferred embodiments and also using the drawings. In the drawings:
a to
a to
a to
Identical elements and elements with the same function are labelled in the figures using the same reference numbers.
The device 1 comprises a connector 3 for carrier air at a first end 2 for transporting away the decontamination agent vapour generated to a space to be decontaminated which is not shown. At the second end 4 (cf.
A free cross-section, i.e. a flow channel 8, is realised axially between the connections, through which the carrier air, in this case fresh air, for example compressed air or ambient air, flows and can thereby take the decontamination agent vapour with it.
The lower device section 5 comprises a metallic evaporator body 9 made of an aluminium alloy. As emerges from
Two rows 14, 15 of blind holes 16, i.e. holes only open at one end, separate and spaced apart from one another are introduced into the evaporator body 9 in the exemplary embodiment shown. The blind holes 16 and recesses are separate from one another, i.e. they are not directly hydraulically interconnected and extend perpendicularly to the carrier air flow direction and therefore perpendicularly to the solution extension of the evaporator body 9. As emerges particularly from
It emerges from
It emerges from
As further emerges from
The device 1 depicted in
Unlike the previously described exemplary embodiment, the evaporator body 9 of the device 1 in accordance with
In the interests of clarity,
The assembly 33 in accordance with
It is evident that the device 1 (high-speed evaporator) is connected to a bypass line 44 to conduct fresh air 38, so that not all fresh air supplied flows through the device 1. As in the exemplary embodiment according to
The device 1 comprises an evaporator body 9 with a trough-like form in an upper section and a prismatic form in a lower section, wherein the upper section laterally encloses a flow channel 8. A cover plate 45, which seals the top of the flow channel 8 in the mounted state, may be fastened to the evaporator body 9 by screws. Supply channels 46 to be commented on later are introduced into the cover plate 45, in this case by milling. The supply channels 46 transport decontamination liquid to be evaporated to adapters 30 for interchangeable supply channels 28. Said supply channels take the form of injection needles made of stainless steel and have a Luer-Lock connection 29 at their upper end for fixing in an adapter 30 in each case.
In the exemplary embodiment shown, the sealing plate 47 which can be screwed to the cover plate 16 closes the groove-like supply channels 46 from above. In addition or alternatively, the supply channels 46 may be closed with an upper wall, preferably welded on subsequently, particularly made of stainless steel.
The supply channels 46 emerge from a central recess 48 (space), into which decontamination liquid to be evaporated is fed by means of a clocked metering pump (not shown) via a supply line.
As can be further seen from
a to 14c show different representations of the evaporator body 9 in accordance with the exemplary embodiment in
a to 15e show the sealing cover 47. This exhibits a central feed 52, through which the decontamination liquid to be evaporated reaches the evaporator. As can be seen from
In addition, six internally threaded holes 53 disposed in a row are provided, wherein an internally threaded hole of this kind is assigned to each feed channel 28 (cf.
a to 16e show the cover plate 45 shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2009 060 512.6 | Dec 2009 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2010/007862 | 12/22/2010 | WO | 00 | 6/22/2012 |
