Patent Publication Number: US-2012031583-A1

Title: Device and method for cooling food machinery

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims the benefit of priority of German Application No. 102010031393.9, filed Jul. 15, 2010. The entire text of the priority application is incorporated herein by reference in its entirety. 
     FIELD OF THE DISCLOSURE 
     The disclosure relates to a machine for producing or processing food as well as to a method for cooling such a machine. 
     BACKGROUND 
     Great demands are made on hygiene when foods are produced or processed. In particular, the ambient air that can come into contact with an open food product must also be as free of germs as possible. A pathogen can reach the product from the contaminated ambient air. It is consequently possible, for example, for sausage meat in a hopper or storage container to come into contact with contaminated ambient air during sausage production. This, in turn, can lead to an impairment of the quality of the product or even to health risks for the end consumer. 
     During the production of foods, however, an unwanted germ load arises again and again, in spite of diligent hygiene. 
     SUMMARY OF THE DISCLOSURE 
     On this basis, one aspect of the present disclosure is to provide a machine for producing or processing foods as well as a corresponding method that contribute to a reduction of the germ load in the ambient air and in the product. 
     It has become apparent that the air cooling of a machine for producing foods can represent a contamination source that is not negligible. Machines and systems in food production, for example, cutters, mixers, emulsifiers, vacuum filling machines, clippers, packaging machines, etc., in some cases need high levels of electric power, whereby the power dissipation creates heat. The machines are customarily cooled with ambient air. In this process, the air is blown through an air duct and into the machine interior with a ventilator. Alternatively, the air is blown out of the machine interior with a ventilator. Because these machines are customarily used in a relatively cool environment, this approach produces effective and efficient cooling. The machine interior here is customarily not accessible for cleaning purposes. The machine interior is likewise usually not hygienically organized, due to the principle. One consequence of this is the risk of the entry of germs with uncontrolled germ reproduction in the machine interior, particularly as a result of the heated air. This exhaust air can unexpectedly be so contaminated that the abovementioned germ contamination problems develop. 
     According to the present disclosure, however, the cooling system is now formed in such a way that the ambient air is not contaminated by a cooling agent with germ contamination. Ambient air here is to be understood as the air in the production area in which the machine is installed. The gel in count in the ambient air and consequently in the product can consequently be substantially reduced. The present disclosure makes possible effective and efficient machine cooling without contamination of the ambient air or the machine interior with germs. 
     In an especially advantageous manner, the cooling system uses air cooling with an air inlet, an air outlet and a ventilating device for generating a cool air flow in the interior of the machine housing, as well as at least one device for removing gel ins from the cooling air. Due to the fact that the germs are removed from the cooling air, the air can be blown off into the production area without reservations and without there being a risk that the product will become contaminated. The cooling agent flow flows freely through the machine housing interior. The interior of the machine housing is limited by the machine housing&#39;s outer walls. Various electronic system components are arranged in the interior of the machine housing as heat generators, around which the cooling air flow flows directly, consequently cooling the components. For the selective flow onto individual components, the cooling agent flow can additionally be conducted in parts. 
     It is advantageous if the device for removing germs comprises a radiation source, preferably a UV radiation source. A UVC radiation source is particularly suitable. It is, however, also possible to remove the get ins from the cooling air with X-rays, gamma rays, electron bombardment, etc. Due to the irradiation, the DNA of the germs, for example, the viruses, bacteria or spores, is modified to the extent that these cells cannot replicate. An effect of greater than 99.99% can be achieved. If a radiation source is used, particularly UV radiation, the result is a very high level of process reliability and production reliability due to the strongly reduced germ load. This leads to a very high level of product quality and a prolonged shelf life. Excellent air hygiene and consequently a healthier work environment for employees can also be realized. No chemicals or other substances have to be introduced into the ambient air or product. No toxic compounds result from the irradiation of the cooling air. There is likewise no development of resistance on the part of the microorganisms. The microorganisms furthermore become inactive in a matter of seconds due to the irradiation. The desired product characteristics are nevertheless preserved. If the air is suctioned from the production area into the machine and then expelled back into the production area, the germs are automatically also removed from the ambient air that has been contaminated by other sources. A radiation source as a device for removing germs has a compact design and can easily be integrated into the machine. A UV source, particularly a UVC source, is economical and has a long service life. At the same time, the energy consumption is low, so that the machine or the ventilation can also run over night. Minimal service life costs consequently result. Lamp replacement can be carried out in a simple and economical manner. The entire cooling air flow can be captured and the germs can be removed. The process is easy to control. 
     The device for removing germs can have a chamber for removing germs from the air, whereby the cooling air flow flows into and out of this chamber. By arranging the radiation source in a corresponding chamber, it can be ensured that the germs are sufficiently removed from the entire cooling air flow with a certain radiation intensity. It is, however, just as easily possible to arrange the radiation source alternatively or additionally freely in the machine housing interior. If the radiation source is located in the machine housing interior, surfaces of individual machine components can also be irradiated and consequently disinfected. It is furthermore also possible to provide the radiation source in a supply air line and/or exhaust air line that are connected to the air inlet or air outlet of the machine housing. The mounting of the radiation source in the supply air or exhaust air line can also very easily be carried out after the fact. The radiation source can also be integrated into the supply air or exhaust air line as a standalone device, i.e., e.g., in the form of a docking station that is attached to, e.g., an inlet or outlet connection piece of the machine housing via a line, particularly a hose. Then, for example, the ventilating device can be arranged in the separate device or the docking station. 
     An electronics box is provided in the machine housing interior for machine control, whereby the machine controller and other sensitive electronic components are arranged in this electronics box. This electronics box is conventionally heated in order to prevent moisture from accumulating due to condensation when the machine cools after being switched off. The radiation source is now arranged in the machine housing interior in an advantageous manner in such a way that the electronics box is heated by the radiation source. This consequently makes it possible to do without extra heating for the electronics box, and the waste heat from the radiation source can be used sensibly. 
     According to a further embodiment, the at least one device for removing germs comprises means for introducing a disinfecting active substance mist in the cooling air flow. The germs are killed off by means of the introduction of the active ingredient mist. Fruit acid, benzoic acid and sorbic acid, as well as lactic acid or hydrogen peroxide, etc., for example, particularly as an aerosol, can be considered here for the active substance. 
     This embodiment also has the advantage of a machine interior with a low germ count. The active substance mist can be distributed throughout the entire machine housing interior by the cooling air flow. There is only a low or even no impairment of the quality of the food due to the active substance mist precipitate. The result is the highest level of process reliability and the highest level of production reliability, which produce a high level of product quality and a prolonged shelf life. The reproduction of microorganisms is effectively prevented, and existing microorganisms are reliably killed. The germs are automatically removed from the contaminated ambient air in the process. A corresponding device can easily be integrated into the machine housing interior or in a supply and/or exhaust air line. A compact, mobile disinfection device can alternatively be used. This mobile disinfection device can, for example, be integrated into the supply or exhaust air line, i.e., e.g., in the form of a docking station that can be connected to an inlet or outlet connection piece of the housing with a line or a hose. The mobile disinfection device can then possibly also comprise the ventilator. The overall results are low costs and a long service life. 
     According to a further embodiment, the air is alternatively or additionally not blown off into the production area, but instead the air outlet is connected to an exhaust air line, by means of which the cooling air flow can be blown off outside of the production area. In this way, contaminated cooling air does not come into contact with the food. It is also possible to conduct the cooling agent within a closed circuit, i.e., it is possible for the exhaust air then to serve again as the supply air for the cooling. In this process, a heat exchange means is provided that cools the exhaust air before it is again fed to the machine as cooling air. It is also possible to feed the cooling air from an area outside. This embodiment represents a closed system that is independent of the ambient air. This does not result in an impairment of the ambient air and consequently the product. Here again, the highest level of process reliability and the highest level of production reliability result, along with a high level of product quality. There are furthermore low costs and a prolonged shelf life. Here again, it is possible to do without the introduction of chemicals and other substances into the ambient air or the product. This solution is very economical, has a long service life, and represents an easily controllable process. No consumable materials are necessary. 
     Finally, the air cooling can alternatively or additionally be replaced with liquid cooling, particularly water cooling, with a closed circuit, which likewise prevents air contamination. The cooling system can also alternatively or additionally be implemented by means of a cooling machine, particularly a compression cooling machine. Here again, there is no contaminated exhaust air. The machine interior is then cooled by heat exchange. 
     It is also possible to integrate at least one filter element into the supply and/or exhaust air line. The filters (coarse, fine, electrostatic filter, etc.) can also reduce the reproduction of the microorganisms and contribute to a low germ count in the machine interior. Here again there is no impairment of the quality of the food, but there is increased process reliability and production reliability, and consequently a high level of product quality. The shelf life of the product can be prolonged. The product characteristics are preserved. The contaminated ambient air is filtered, which leads to the removal of germs and filtration. Particularly in combination with a downstream device for removing germs, it is possible to catch the killed germs and other unwanted air components. 
     It is likewise advantageous if the machine housing additionally or alternatively is formed as a machine design that is open or that can be opened. In this way, the machine housing interior can be periodically cleaned and disinfected, which leads to a considerable reduction in the germ load of the cooling air flow. 
     The machine is preferably a machine for producing or processing food, particularly a machine from the following group: Filling machine, cutter, emulsifier, clipper, packaging machine, etc. 
     In the method according to the disclosure, the cooling means is consequently, as explained previously, treated or conducted in such a way that the ambient air is not contaminated with germs. This is particularly brought about by means of irradiation or a disinfecting active substance mist. The cooling agent flow is irradiated with UV radiation, particularly UVC radiation. During the irradiation of the cooling air flow, an electronics box can be heated by the radiant heat. 
     The possibly necessary controller for the device for removing germs here can optionally be integrated into the machine controller or it can be executed as a standalone controller. The intensity of the radiation source is adjustable, and is particularly adjusted or controlled or regulated depending on the germ density in the air and/or the irradiation duration. The change in the radiation intensity can, for example, take place by switching on one or more radiation sources, or by changing the output. The quantity of disinfectant introduced into the air flow can correspondingly be adjusted or controlled or regulated by time and the introduction duration of the disinfectant can correspondingly be adjusted or controlled or regulated depending on the germ density. 
     A combination of at least two of the embodiments described above is also possible. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure is explained in more detail in the following with reference to the following figures. 
         FIG. 1  a shows a rough schematic cut through a machine according to a first embodiment of the present disclosure, in which the device for removing germs is arranged in a chamber for removing germs from the air in the machine housing interior in the area of the effluent cooling air flow. 
         FIG. 1   b  shows a detail of an embodiment according to the disclosure in a rough schematic sectional representation in which the device for germ removal is provided in the exhaust air line. 
         FIG. 2   a  shows a rough schematic cut through a machine according to a further embodiment of the present disclosure in which a device for removing germs is arranged within the machine housing interior in a chamber for removing germs from the air in the area of the inflowing cooling air flow. 
         FIG. 2   b  shows a rough schematic view of an embodiment according to the disclosure in a rough schematic sectional representation in which the device for removing germs is provided in the supply air line. 
         FIG. 3  shows a rough schematic view of a cut through an embodiment according to the present disclosure in which the device for removing germs is arranged freely in the machine housing interior. 
         FIG. 4  shows a rough schematic view of a cut through an embodiment of a machine in which a radiation source is arranged in the area of an electronics box. 
         FIG. 5  shows a rough schematic view of an embodiment according to the present disclosure in which the cooling system comprises a cooling machine. 
         FIG. 6  shows a rough schematic view of a cut through an embodiment according to the present disclosure in which air is supplied from the outside and is blown off outside the production area. 
         FIG. 7  shows an embodiment in a rough schematic sectional representation in which the cooling agent is conducted in a circuit. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a rough schematic view of a cut through a machine  1  for producing or processing food. Here the machine is for producing or processing food, for example, a filling machine for producing sausages. The machine is installed in a production area with ambient air  12 . The machine here comprises e.g., a hopper  8  for filling in the filling, e.g., sausage meat, a conveyor  5   a  with a corresponding drive that slides the sausage meat into a filling pipe  9  as well as a filling pipe  9  by means of which the sausage meat is expelled into a shirred sausage casing on the filling pipe. Such filling machines are common knowledge. The precise construction and function of such a filling machine are shown in EP 0250733, for example, so that a detailed description of such a machine is dispensed with. 
     The machine here comprises a closed machine housing  10  in which the different system components, particularly also heat generators, are arranged. As a heat generator, this system has, e.g., the conveyor  5   a  with a corresponding drive for transporting the filling. The device furthermore has as heat generators, for example, a drive  5   b  for turning the filling pipe  9  and a transformer  5   c . Furthermore, for example, a drive  5   d  for external attachments, such as, e.g., an attachment passing machine, can also be provided. The heat generators  5   a, b, c, d  etc., are located in a relatively small area in the closed housing  10 . Machines and systems in food production need high levels of electrical power, whereby a correspondingly large level of waste heat arises, so that the interior  16  of the housing  10  must be cooled. 
     In this embodiment, the cooling system is an air cooling system with an air inlet  2  and an air outlet  4  in the housing, as well as a ventilating device  3  for generating a cooling air flow in the interior  16  of the machine housing  10 . Here the ventilating device  3  is arranged in the area of the air inlet  2  within the housing  10 . The ventilating device  3  that generates the cooling air flow  11  can, however, likewise be provided in a supply air line  14 . Used as the ventilating device  3  are radial or axial ventilators, for example. Additionally or alternatively, the air can also be suctioned in and blown off from the machine housing interior  16  via a ventilating device in the exhaust air area, i.e., in an exhaust air line  15  or before an air outlet  4  (not shown). In this embodiment, ambient air is suctioned in from the production area  12  as the cooling air flow L and then discharged again, as shown by the arrows, via an air outlet of the housing. The air inlet  2  and the air outlet  4  can be connected to corresponding supply and exhaust air lines  14  and  15  or corresponding connection pieces, however they can also be formed only as an opening in the housing. Because the machines are customarily used in a relatively cool environment, this approach produces effective and efficient air cooling. 
     In order to prevent air  12  from being contaminated with germ-ridden cooling air in the production area, a device  7  for removing germs from the cooling air is provided. In this special embodiment, a chamber for removing germs from the air  6  is provided for this purpose in the area of the air outlet  4 . The closed chamber has an inflow opening  6   a  and outflow opening  6   b  for the cooling air flow L. Here the chamber is arranged at the housing wall, so that the opening  6   b  essentially corresponds to the air outlet  4 . According to a first embodiment, a radiation source  7  for removing germs is provided within the chamber. This radiation source can be one or more UV, particularly UVC, radiation sources. It is, however, also possible to use an X-ray or gamma radiation source or to remove germs from the air flow by means of electron bombardment, etc. A UVC radiation source is particularly advantageous, however. A UVC radiation source here preferably has an output of 15 to 250 watts with a cooling agent flow in a range from 1 to 600 m 3 /h, as well as an inner volume of the housing in a range from 100 1 to 10,000 1. The radiation, particularly the UVC radiation, brings about the formation of DNA mutations, which lead to structural changes in the DNA helix of the germs and impair replication and transcription. The viruses, bacteria and spores are all deactivated thereby due to a change in the DNA. Such a number of DNA errors arise that the cells can no longer divide. The effect that can be achieved (killing of the germs) is &gt;99.99%. Due to the fact that the cooling air flow L flows through the chamber  6 , it is ensured that the entire cooling air flow is irradiated once with sufficient intensity. The emerging cooling air, which is as germfree as possible, consequently does not contaminate the ambient air  12 . Accordingly, virtually no pathogens can reach the product, e.g., sausage meat, due to the air flow from the contaminated ambient air  12 . The product quality is not impaired, and there are also no health risks arising for the end consumer or the employees in the area  12 . 
     As is shown in  FIG. 1   b , the device for removing germs  7  can be arranged not only within the housing  10  but also in an exhaust air line  15 , as shown in  FIG. 1   b . The device for removing germs can also be integrated into the exhaust air line  15  in the form of a docking station, meaning as a standalone device, whereby the docking station can be connected to an outlet connection piece with a line or hose. This docking station can also comprise the ventilator  3 . 
       FIG. 2   a  shows a further embodiment of the present disclosure that corresponds to the embodiment shown in  FIG. 1 , whereby the device for removing germs  7  is, however, arranged in the area of the air inlet  2 , likewise in a chamber for removing germs from the air  6  through which the cooling air flow L flows and whereby the germs are removed from it by the radiation. As follows from  FIG. 2   b , here the device for removing get ins  7  can also be arranged in the supply air line  14 , which leads to the air inlet  2 . As a standalone device in the form of a docking station, the device for removing germs  7  can also be connected here to the inlet or outlet connection piece of the housing, for example, with a hose or a line, and consequently form a part of the supply air line. This docking station can optionally also comprise the ventilator  3 . While in the case of the embodiment shown in  FIG. 1   a ,  1   b  it is ensured that only cooling air from which the germs have been completely removed enters directly into the area  12 , the embodiment as shown in  FIG. 2 ,  2   b  has the advantage that air from which the germs have already been removed flows into the machine housing interior  16  so that germ contamination of the surfaces can be reduced. It is particularly advantageous if corresponding devices for removing germs from the cooling air are provided both in the area of the air inlet and in the area of the air outlet. 
     According to a further embodiment, however, it is also possible to arrange the device for removing germs  7  freely within the housing  10  in the machine housing interior  16 . This embodiment has the advantage that surfaces of the individual machine components in the interior of the housing can also be disinfected, for example by means of the radiation source. 
       FIG. 4  shows a further embodiment according to the present disclosure. Here the radiation source  7 , particularly the UVC radiation source, can be arranged so close to an electronics box  11  that the electronics box  11  is heated by the radiation and/or by the waste heat of the radiation source, e.g., by 10-20° K. The electronics box comprises, e.g., the machine controller. The heating of the electronics box is advantageous because in this way the accumulation of condensation water on the electronic parts is prevented. In this way it is possible to forego heating the electronics box  11 . 
       FIGS. 1 to 3  have been described in conjunction with a device for removing germs  7  that comprises a radiation source. Instead of a radiation source, however, a device can also be provided that introduces a disinfecting active substance mist into the cooling air flow. This device is preferably provided with a nozzle that is connected to a storage container for the active substance via a line that is not shown, via a pump. A vaporizer can also be provided instead of the pump. The nozzle is formed in such a way that a fine mist can be produced. Germs are killed due to the introduction of the aerosol mist into the cooling air flow. The following active substances can be considered for this: fruit acid, benzoic acid, sorbic acid, lactic acid; hydrogen peroxide, etc. Preferably a fine aerosol mist is created thereby. The nozzle can thereby, as was described in conjunction with the preceding embodiments in conjunction with  FIG. 1   a, b ,  2   a, b  and  3 , be arranged at the corresponding locations at which the radiation source  7  is also arranged, i.e., in the area of the air inlet and/or air outlet in corresponding chambers for removing germs from the air  6  and/or in the supply and exhaust air lines  14 ,  15  and/or also freely in the machine housing interior  16 . The aerosol mist can be introduced continuously in small amounts, e.g., 10 to 450 ml/h. It is, however, also possible to introduce the aerosol mist at certain intervals instead of continuously. This is sufficient because the disinfecting active substance precipitates on the surfaces and as a result, increased germ formation is prevented and existing germs are killed off. 
     This embodiment consequently also has the advantage of a low germ count in the machine interior if the aerosol mist is uniformly distributed by means of the cooling air flow L throughout the entire machine interior and leads to disinfection of the surfaces. The quality of the food is therefore only slightly impaired or is not impaired at all. This solution is also simple to integrate into the machine. An equivalent solution is especially economical to implement. The germ removal can take place during production with the machine, but also during pauses or other standstill periods, such as, e.g., over night. The device for removing germs preferably has a controller that activates the individual actuators of the device for removing germs. The controller can thereby optionally be integrated into the machine controller or it can be executed as a standalone controller. Integration of the controller into the machine controller is advantageous because then the user can operate the entire machine, including cooling and cooling air disinfection, from an operator interface. 
     It is then advantageous if the intensity of the radiation source is controlled or regulated, for example, depending on the germ density in the air. The germ density can, for example, be registered via a corresponding device in situ in the device or in the ambient air and, for example, be determined by establishing a culture in the known way. The intensity of the radiation source can likewise be controlled or regulated or adjusted depending on the radiation duration. The intensity can, for example, be adjusted by switching on one or more radiation sources. The intensity can also be adjusted by varying the output of the radiation source. 
     The quantity of disinfectant that is introduced into the cooling flow per time and the duration of the injection can be adjusted and can be controlled or regulated particularly depending on the germ density in the air. 
       FIG. 5  shows a further embodiment according to the present disclosure. To prevent the ambient air  12  from becoming contaminated with germs here, a cooling machine  13 , particularly a compressing cooling machine  13 , is provided here instead of an air cooling system  2 ,  4 ,  3 . The air in the machine housing interior  16  is cooled by means of heat exchange across a surface of the cooling machine. The cooling machine is driven, for example, electrically or e.g., with gas, etc. 
       FIG. 6  shows a further embodiment according to the present disclosure. In order to prevent contamination of the ambient air by means of the cooling agent that is contaminated with genus, the exhaust air line  15  of the air cooling system is of such a length that the cooling air flow L can be blown out beyond the production area. Pipes, hoses or the like can be connected to the machine  1  for this purpose. The air provided for cooling can also optionally be suctioned in or blown in from the outside via the supply air line  14 . 
       FIG. 7  shows a further embodiment according to the present disclosure. Here the cooling air flow L can be conducted in a closed circuit via a corresponding closed loop  15 ,  14 . This means that the cooling air flow L is introduced into the machine or into the housing  10  for cooling again from the air outlet  4  via the air inlet  2 . For this purpose, preferably a heat exchange device  17  is provided that cools off the heated cooling air flow. The waste heat gained from the heat exchanger can be reused for other purposes. This has the advantage that on the one hand, the interior of the housing  10  can be sufficiently cooled and the waste heat can be reused efficiently, but without contaminating the ambient air  12 . A correspondingly closed circuit can also be implemented by conducting liquid cooling in the circuit. Liquid cooling with an open circuit is also possible, however. 
     Even although it is not shown, at least one filter element can be arranged in the area of the air inlet  2  and/or the air outlet  4  or in the supply air line  14  and/or exhaust air line  15 , in addition to or as an alternative for cleaning the cooling air flow. To be considered as filter elements are, for example, coarse, fine, electrostatic or wet air filters. The corresponding filters also serve to reduce the germs. The filters can catch killed germs and other undesired air components. Filters with a disinfecting effect, e.g., filters with a silver or titanium dioxide coating, can also be used. 
     It is also advantageous if the housing is formed as an open machine design, or as a machine design that can be opened. This makes it possible to clean the machine interior. Microorganisms that are present can consequently be killed and it is possible to reduce the development of new germ contamination in the cooling air. In the case of the open machine design, the housing has a sufficiently large opening on at least one side. The housing can also be formed in such a way that, e.g., at least one wall of the housing  10  can be at least partially opened or can be completely removed from a frame. 
     The individually shown embodiments can also be combined with one another.