CH719386A1 - Vacuum pump and installation for processing and/or packaging food products. - Google Patents

Abstract

The invention relates to a vacuum pump (1), comprising a suction (11), a discharge (9) and an interior volume intended to be traversed by the gases entrained from the suction (11) to the discharge (9) by the pumping by the vacuum pump. The vacuum pump (1) comprises at least one sterilization element (15) of at least a portion (18) of the interior volume. The invention also relates to an installation for processing and/or packaging food products.

Description

Technical field of the invention

The present invention relates to vacuum techniques. More specifically, it relates to a vacuum pump, as well as an installation for processing and/or packaging food products.

State of the art

[0002] The vacuum packaging of food is known. It is carried out in installations comprising a vacuum chamber that one or more connecting ducts connect to one or more vacuum pumps. The function of the vacuum pump(s) is to produce and then maintain a vacuum in the vacuum chamber. In addition to food packaging, food preparation can be carried out in such a vacuum chamber.

[0003] The very low pressure in the vacuum chamber promotes the evaporation of liquids present in the food and/or their transformation into volatile aerosols. Products from food can thus be sucked in particular in a gaseous form or in the form of aerosols in the connecting pipe or pipes, towards the vacuum pump or pumps. As a result, the connection duct or ducts between the vacuum chamber and the vacuum pump or pumps can be gradually soiled by food matter from the food in the vacuum chamber. There is then a risk that pathogenic microorganisms such as bacteria develop in the connecting duct(s) between the vacuum chamber and the vacuum pump(s), which must absolutely be avoided for health reasons.

To prevent pathogenic microorganisms such as bacteria from developing in the connection conduit(s) between the vacuum chamber and the vacuum pump(s), it is known to regularly disconnect and clean these connection conduits, which requires maintenance and sometimes the temporary shutdown of the installation.

Brief description of the invention

[0005] The object of the invention is at least to make it possible to increase health safety in and/or around installations where a vacuum is produced by one or more vacuum pumps.

According to the invention, this object is achieved thanks to a vacuum pump which comprises a suction, a discharge, an interior volume intended to be traversed by the gases entrained from the suction to the discharge by the pumping by the vacuum pump. vacuum, as well as at least one element for sterilizing at least a portion of the interior volume.

[0007] It is possible for the sterilization element to be unique or to be one of several sterilization elements included in the vacuum pump. The sterilization element(s) can be positioned so as to sterilize a potential focus for the development and dissemination of microorganisms or a buffer zone between an upstream region which may be upstream of the suction of the pump and a downstream region which may be the surrounding atmosphere.

[0008] If the vacuum pump according to the invention is connected to a vacuum chamber by a connecting pipe, the risk of contamination of the vacuum chamber by microorganisms from the vacuum pump is reduced, in particular in the event that a scheduled cleaning of the connection duct is not carried out until after the date originally planned, is incorrectly carried out or is omitted.

[0009] Advantageously, the interior volume comprises a buffer zone which can be sterilized by the sterilization element or elements, this buffer zone comprising a passage for all of the gases entrained by the pumping by the vacuum pump.

[0010] The buffer zone can prevent upstream contamination by microorganisms present downstream of this buffer zone. Also, viruses for example coming from food in a vacuum chamber can be destroyed in the buffer zone and thus not be expelled into the surrounding atmosphere, by the discharge of the vacuum pump.

[0011] When provided, the entire buffer zone is sterilized. The sterilization of the entire buffer zone may however concern only one or more microorganisms and/or only one or more viruses. In this sense, the sterilization of the entire buffer zone may only be partial. It can also be total by eliminating any micro-organism and/or any virus in the buffer zone.

[0012] Advantageously, the buffer zone extends as far as the suction of the vacuum pump.

[0013] When this is the case, the buffer zone can prevent contamination of the suction of the vacuum pump by microorganisms from occurring and then spreading downstream of the vacuum pump, from the suction of the vacuum pump, and reaches, for example, a vacuum chamber where food products are processed and/or vacuum packed.

[0014] Advantageously, the vacuum pump comprises at least one pumping chamber where the entrainment of the gases by the vacuum pump takes place, at least part of the passage of the buffer zone being located upstream of the pumping chamber .

[0015] Advantageously, the vacuum pump comprises a grid for filtering the pumped gases, this grid being located upstream of the pumping chamber, at least part of the passage of the buffer zone being located upstream of the grid.

[0016] Advantageously, an upstream surface among two opposite main surfaces of the grid can be sterilized by the sterilization element or elements.

[0017] Advantageously, the sterilization element is an ultraviolet light source.

The at least one ultraviolet light source produces ultraviolet light alone or ultraviolet light and one or more other lights. Advantageously, the ultraviolet light source or sources produce ultraviolet light in a wavelength range ranging from 250 nm to 280 nm. When this is the case, ultraviolet light has a very high efficiency in suppressing viruses such as rotavirus and several pathogenic bacteria including Escherichia coli and staphylococcus aureus. More advantageously, the one or more ultraviolet light sources produce ultraviolet light in a wavelength range from 260 nm to 270 nm. When this is the case, ultraviolet light has an even higher efficacy in suppressing viruses such as rotavirus and several pathogenic bacteria including Escherichia coli and Staphylococcus aureus.

[0019] Advantageously, the source of ultraviolet light is one of several sources of ultraviolet light which the vacuum pump comprises and which are capable of illuminating together an entire portion of the interior wall delimiting and surrounding the passage of the buffer zone . In this way, this entire wall portion can be effectively disinfected and the buffer zone can effectively play its role as a barrier against microbial contamination between a zone upstream of the buffer zone and a zone downstream of the buffer zone.

[0020] Advantageously, the vacuum pump comprises an attached conduit forming the suction of the vacuum pump, this attached conduit being provided with the sterilization element. In this way, any standard pump can be transformed into a pump according to the invention.

[0021] Advantageously, the sterilization element is a heating element. This heating element can effect heating by radiation, for example of the buffer zone. The heating element can also be an annular electrical resistor surrounding and delimiting the passage of the buffer zone.

[0022] Advantageously, the vacuum pump is a lubricated pump comprising a pumping chamber where the gas is driven by the vacuum pump, as well as the lubricating oil present in particular in the pumping chamber, the the lubricating oil being or comprising the sterilizing element.

[0023] Advantageously, the sterilization element is or comprises an antiseptic chemical product.

[0024] The invention also relates to an installation for processing and/or packaging food products, which comprises a vacuum chamber and at least one vacuum pump as defined above, the suction of this vacuum pump being connected to the vacuum chamber.

Brief description of the drawings

Other advantages and characteristics will emerge more clearly from the description which will follow of several particular embodiments of the invention given by way of non-limiting examples and represented in the appended drawings, among which: - figure 1 is a perspective view, with cutaway, of a vacuum pump according to a first embodiment of the invention, - figure 2 is a diagram of an installation which is in accordance with the invention and which is more precisely an installation processing and/or packaging of food products, - figure 3 is a perspective view in section of an upstream sub-assembly of a vacuum pump according to a second embodiment of the invention, - the Figure 4 is a perspective and cross-sectional view of an upstream sub-assembly of a vacuum pump according to a third embodiment of the invention, and - Figure 5 is a perspective and cross-sectional view of a vacuum pump according to a fourth embodiment of the invention.

Description of a preferred mode of the invention

In Figure 1, a vacuum pump 1 according to a first embodiment of the invention is more specifically a lubricated vane pump. It comprises an upstream sub-assembly 2 and a pumping chamber 3, in which a rotor 4 provided with several vanes 5 is mounted so as to be rotatable. A motor 6 is provided to drive the rotor 4 in rotation.

The pumping chamber 3 communicates with an enclosure 7, the lower part of which forms a lubricating oil tank (not visible). In the upper part of the enclosure 7 is mounted an oil filter 8 intended to extract the oil present in the pumped gases before the evacuation of these gases, for example into the atmosphere, by the discharge 9 of the vacuum pump. 1.

[0028] When the rotor 4 rotates on its axis, the vanes 5 entrain the gases present in the pumping chamber 3 and expel them towards the enclosure 7. This generates a suction by the upstream sub-assembly 2.

[0029] Here, as in the appended claims, the terms "upstream" and "downstream", as well as similar terms, refer to the direction in which the gases pumped by the vacuum pump 1 flow.

The upstream subassembly 2 comprises an assembly of several successive parts 10a and 10b forming a conduit 10, the upstream end of which is the suction 11 of the vacuum pump 1. The downstream end of the conduit 10 communicates with the pumping chamber 3. A grid 12 for filtering the aspirated gases entering through the suction 11 is mounted in the conduit 10. A non-return valve 13 is mounted downstream of the grid 12, in the conduit 10.

The upstream subassembly 2 is placed upstream of the pumping chamber 3. In a particular case of the embodiments of the invention, the upstream subassembly 2 is placed directly upstream of the pumping chamber 3 .

The part 10a is provided with several sterilization elements, each of which is an ultraviolet light source 15. For example, each ultraviolet light source 15 can be an LED. The ultraviolet light sources 15 are arranged and directed so as to illuminate together the entire interior wall 16 of the part 10a, as well as the upstream surface 17 of the grid 12. The ultraviolet light beams emitted by the ultraviolet light sources 15 are symbolized by the arrows F in Figure 1.

The area delimited by the part 10a is a buffer zone 18 that the ultraviolet light emitted by the ultraviolet light sources 15 sanitizes in its entirety by destroying any microorganisms present and any viruses present. The buffer zone 18 forms a passage through which flows all of the gases pumped by the vacuum pump 1. The buffer zone is thus an intermediate zone between an upstream region and a downstream region along the path of the gases entrained by the pumping by the vacuum pump 1. The buffer zone 18 is located upstream of the pumping chamber 3, as well as the grid 12, and extends to the suction 11.

In Figure 2, an installation according to the invention is an installation for processing and / or packaging of food products. It comprises a vacuum chamber 50, the vacuum pump 1, as well as a connection duct 51 which connects an opening of the vacuum chamber 50 to the suction 11 of the vacuum pump 1. In the vacuum chamber 50 , food products are vacuum packed. In the vacuum chamber 50, it is also possible to process food products and, optionally, to package them under vacuum afterwards.

[0035]A possible contamination, for example by a bacterium upstream of the buffer zone 18, cannot cross this buffer zone 18, towards the suction 11 and towards a connecting pipe such as the connecting pipe 51 connecting the vacuum chamber 50 to the vacuum pump 1 in the case of the processing and/or packaging installation represented in FIG. 2. In this case, the buffer zone 18 thus prevents contamination of the vacuum chamber 50 from the vacuum pump. vacuum 1, by a pathogenic microorganism.

[0036] In addition, if viruses, for example originating from food in the vacuum chamber 50, are driven by the gases sucked into the vacuum pump 1, these viruses are destroyed in the buffer zone 18 and are thus not expelled into the surrounding atmosphere, through the discharge 9.

If food material coming from the vacuum chamber 50 is on the grid 12 after having been stopped by this grid 12, it receives ultraviolet radiation from at least part of the ultraviolet light sources 15. This material food present on the grid 12 is thus sanitized and cannot become a breeding ground for microorganisms and contamination of other regions such as the connecting conduit 51 and the vacuum chamber 50, by such microorganisms.

[0038] An upstream sub-assembly 102 of a vacuum pump according to a second embodiment of the invention is represented in FIG. 3. In what follows, only that by which the vacuum pump according to the second embodiment of the invention differs from the vacuum pump 1. Furthermore, when a referenced part of the vacuum pump according to the second embodiment of the invention is identical or equivalent to a referenced part of the vacuum pump 1, its reference is constructed by adding 100 to the reference designating this part referenced on the vacuum pump 1. In this way, the references for the grid 112 and the non-return valve 113 are constructed in particular.

In addition to the parts 110a and 110b, the conduit 110 of the upstream subassembly 102 comprises an attached conduit 120, which is provided with ultraviolet light sources 115. The attached conduit 120 comprises the suction 111 of the vacuum pump according to the second embodiment of the invention. In the example represented, no source of ultraviolet light equips the part 110a. When this is the case, the insert pipe 120 can be mounted on a vacuum pump initially devoid of ultraviolet light source 115 and thus provide this vacuum pump with ultraviolet light sources 115 and with a buffer zone 118.

[0040] The buffer zone 118 comprises the passage delimited by the insert pipe 120 and extends as far as the suction 111. The inner wall 121 of the insert pipe 120 is entirely illuminated by the sources of ultraviolet light 115. The entire zone buffer 118 including this inner wall 121 is thus sanitized by ultraviolet radiation. A possible contamination by a microorganism upstream of the buffer zone 118 cannot cross this buffer zone 118, towards the suction 111 and towards a vacuum chamber when such a vacuum chamber is connected to this suction 111.

[0041] An upstream sub-assembly 202 of a vacuum pump according to a third embodiment of the invention is represented in FIG. 4. In what follows, only that by which the vacuum pump according to the third embodiment of the invention differs from the vacuum pump 1. Furthermore, when a referenced part of the vacuum pump according to the third embodiment of the invention is identical or equivalent to a referenced part of the vacuum pump 1, its reference is constructed by adding 200 to the reference designating this part referenced on vacuum pump 1.

Like part 10a, part 210a of conduit 210 is provided with sterilization elements. Instead of being a source of ultraviolet light 15, each of these sterilization elements is a heating element 215. The heating elements 215 are able to heat by radiation the inner wall 216 of the part 210a and the upstream surface 217 of the grid 212 in order to bring them to a temperature at which at least certain microorganisms are destroyed. For example, this temperature may be greater than about 50°C. It is preferably greater than about 70°C and even more preferably greater than about 120°C. The entire buffer zone 218 including the inner wall 216 and the upstream surface 217 is thus sterilized up to the suction 211. The radiation emitted by the heating elements 215 is symbolized by the arrows R in FIG. 4.

A vacuum pump 301 according to a fourth embodiment of the invention is shown in Figure 5. In what follows, only what the vacuum pump 301 differs from the vacuum pump 1 is described. Furthermore, when a referenced part of the vacuum pump 301 is identical or equivalent to a referenced part of the vacuum pump 1, its reference is constructed by adding 300 to the reference designating this referenced part on the vacuum pump 1 For example, the reference of the delivery 309 of the vacuum pump 301 is constructed like this.

As in the first embodiment of the invention, the lower part of the enclosure 307 forms a tank 330 which is a lubricating oil tank and which is used to recover and store the oil 331 for lubricating the pallets (not visible) of the vacuum pump 301 in a manner known per se in lubricated vane pumps. Still as in the first embodiment, the upper part of the enclosure 307 contains an oil filter 308 designed to extract the lubricating oil 331 present in the gases after they have been driven by the vanes (not visible) into the combustion chamber. pumping (not visible). The lubricating oil 331 extracted by the oil filter 308 flows by gravity to the tank 330.

The lubricating oil 331 contains a sterilization element which is an antiseptic chemical capable of suppressing one or more microorganisms and/or one or more viruses. For example, this antiseptic chemical can be p-Chloro-m-cresol (PCMC) or any other chemical that may be suitable as a biocide such as o-Phenylphenol (OPP), lodopropynylbutylcarbamate (IPBC), Benzisothiazolinone (BIT) or Bronopol. Alternatively, the lubricating oil 331 may itself be, by virtue of its composition, the sterilization element. The lubricating oil 331 sterilizes a buffer zone 318 which includes the pumping chamber and the region comprising the filter cartridges 332 of the oil filter 308. Viruses possibly sucked up by the vacuum pump 301 are destroyed at the level of the buffer zone 318 and are thus not discharged into the surrounding atmosphere by the discharge 309.

The vacuum pump 301 may include ultraviolet light sources as in the first embodiment of the invention, in which case these ultraviolet light sources may be arranged and oriented as the ultraviolet light sources 15 are in the first embodiment or as the ultraviolet light sources 115 are in the second embodiment of the invention. The vacuum pump 301 may also include heating elements that can be arranged and oriented like the heating elements 215 are in the third embodiment of the invention. The vacuum pump may also include neither an ultraviolet light source nor a heating element.

In a vacuum pump not shown according to a fifth embodiment of the invention, sources of ultraviolet light can be provided in an enclosure having the same function as the enclosure 307 of the fourth embodiment of the invention . In this case, these sources of ultraviolet light can be provided in the lower part of the enclosure, so as to be able to illuminate the lubricating oil and the oil tank, or in the upper part of the enclosure, for example instead of one of several oil filter cartridges.

The invention is not limited to the embodiments described above. In particular, although the vacuum pump in these embodiments is a lubricated vane pump, the invention is not limited to lubricated vane pumps. Indeed, any type of vacuum pump, lubricated or non-lubricated, can be in accordance with the invention. In particular, a vacuum pump according to the invention can be chosen from among a vane pump, a screw pump, a gear pump, an ejector and a lobe pump.

Claims (14)

1. Vacuum pump, comprising a suction (11; 111; 211), a discharge (9; 309) and an interior volume intended to be traversed by the gases entrained from the suction (11; 111; 211) to the discharge ( 9; 309) by pumping by the vacuum pump, characterized in that it comprises at least one element (15; 115; 215; 331) for sterilizing at least one portion (18; 118; 218; 318) of the interior volume. 2. Vacuum pump according to claim 1, characterized in that the sterilization element (15; 115; 215; 331) is one of several sterilization elements (15; 115; 215; 331) that comprises the pump empty. 3. Vacuum pump according to claim 1 or 2, characterized in that the interior volume comprises a buffer zone (18; 118; 218; 318) sterilizable by the sterilization element(s) (15; 115; 215; 331), this buffer zone (18; 118; 218; 318) comprising a passage for all of the gases entrained by the pumping by the vacuum pump. 4. Vacuum pump according to claim 3, characterized in that the buffer zone (18; 118; 218) extends as far as the suction (11; 111; 211) of the vacuum pump. 5. Vacuum pump according to claim 3 or 4, characterized in that it comprises at least one pumping chamber (3) where the entrainment of gases by the vacuum pump takes place, at least part of the passage of the buffer zone (18; 118; 218) located upstream of the pumping chamber (3). 6. Vacuum pump according to any one of claims 3 to 5, characterized in that it comprises a grid (12; 112) for filtering the pumped gases, this grid (12; 112) being located upstream of the chamber pump (3), at least part of the passage of the buffer zone (18; 118; 218) being located upstream of the grid (12; 112). 7. Vacuum pump according to claim 6, characterized in that an upstream surface (17; 217) among two opposite main surfaces of the grid (12; 112) can be sterilized by the sterilization element(s) (15; 215) . 8. Vacuum pump according to any one of the preceding claims, characterized in that it comprises an insert pipe (120) forming the suction (111) of the vacuum pump, this insert pipe (120) being provided with at least one sterilization element (115). 9. Vacuum pump according to any one of the preceding claims, characterized in that at least one of the sterilization elements is an ultraviolet light source (15; 115). 10. Vacuum pump according to claim 9, characterized in that the source of ultraviolet light is one of several sources of ultraviolet light (15; 115) which the vacuum pump comprises and which are able together to illuminate any an interior wall portion (16, 17; 121) delimiting and surrounding the passage of the buffer zone (18; 118). 11. Vacuum pump according to any one of the preceding claims, characterized in that at least one of the sterilization elements is a heating element (215). 12. Vacuum pump according to any one of the preceding claims, characterized in that the vacuum pump is a lubricated pump comprising a pumping chamber where the entrainment of gases by the vacuum pump takes place, as well as the lubricating oil (331) present in particular in the pumping chamber, the lubricating oil (331) being or comprising at least one of the sterilization elements. 13. Vacuum pump according to claim 12, characterized in that the sterilizing element is or comprises an antiseptic chemical. 14. Plant for processing and/or packaging food products, comprising a vacuum chamber (50), characterized in that it comprises at least one vacuum pump (1; 301) according to any one of the preceding claims , the suction (11; 111; 211) of this vacuum pump (1; 301) being connected to the vacuum chamber (50).