GB2140396A - Back pressure nozzle cleaning apparatus - Google Patents

Abstract

A back pressure nozzle cleaning apparatus comprises a cap (2) having a flow restricting means (3) adapted to be removably connected to a filling nozzle (1) in an aseptic processing and filling system for foods or medicines. Heating medium such as hot water or steam is passed through the system and the cap (2) on the filler nozzle (1) makes it possible to pressurize the heating medium in the system to the extent that enough high temperature is established to heat sterilize the inside of the system while permitting the flow of the heating medium through the system. in an alternative embodiment (Fig. 2, not shown) the cap comprises a plate 13 and the flow restricting means is formed by orifice 10. <IMAGE>

Description

SPECIFICATION Back pressure apparatus This invention relates to a back pressure apparatus for high temperature sterilizing the inside of an aseptic processing and filling system for foods or medicines (hereinafter merely called- as "system"), which is adapted to be connected to a filler nozzle of the system to maintain a sterilizing steam or hot water inside the system at a predetermined pressure during the sterilization of the system.

In general, when aseptic processing the products such as foods or medicines it is necessary to make an aseptic condition an aseptic processing and filling system including various apparatus covering froma sterilizing apparatus to a filling apparatus, a delivery pump, pipes valves and the like to which the products tend to directly contact, prior to the production and filling operation of the system.

To this end, there are several conventional methods, for example, of passing sterilizing agents through the system; of heating water to a high temperature by a heat-sterilizing apparatus and introducing the hot water into the system; and of introducing steam through a steam supply piping into the system to heat sterilize it. However, the method of using the sterilizing agents has been hardly used, since the agents sometimes would be remained in the system and be mixtured into the products, which would cause undesirable sanitary problems. Accordingly, the heat-sterilizing methods using hot water or steam have been acutally adopted for the system.

The heat-sterilizing method above mentioned has been usually carried out under the conditions; sterilizing time: 20-45 minutes, and sterilizing temperature: 1 20-1 40 C. In this case, the hot water or steam in the inside of the system should be held at a pressure above the atmospheric pressure (i.e. pressure for suppressing the boiling of water; this pressure is called as "back pressure in the present specification.) in order to maintain the hot water or steam at a temperature above 100"C. Furthermore, it is required that the hot water or steam continues to flow through the system without being stayed therein, since if they would be stayed in the system, their temperature is lowered, due to the heat radiation from the inside of the system to the atmosphere, to the extent that the sterilization of the inside of the system would become insufficient.

Meanwhile, filler nozzles have been designed to have different shapes depending on the properties of the products to be filled, in general, that in the filling process, any of the nozzle is arranged that it is opened to fill one of containers with the product and then the nozzle is fully closed to interrupt the filling until the next conteiner is conveyed in place.

Because of the function of the conventional filler nozzles as described above, therefore, it is impossible to maintain the hot water or steam in the system at a pressure above the atmospheric pressure enough to provide a temperature required for sterilization while permitting a continuous flow of heated water and vapour through the system when the heat sterilization of the system is carried out prior to the filling production.

An attempt has been heretofore made to mount device sterilizing the interior on the filler nozzle an attachment device which is connected to back pressure device, such as a pressure control valve or a steam trap, by means of a pipe to establish enough pressure of the hot water or steam in the system to sterilize it while permitting the flow of hot water or steam through the system. However, there has been a complicatedness and difficulty in manually mounting the above attachment device on the filler nozzle in view of the fact that a number of parts are commonly mounted in the vicinity of the filler nozzle.

In addition, since the filler nozzle and the attachment device become hotter, it is impossible to manually remove the attachment device immediately after the interior of the system has been heat sterilized, they must be left for about thirty minutes to cool them to the ambient temperature.

Furthermore, during removal of the attachment device after cooling down as described above, the attachment device must be carefully handled so as to avoid any contamination of the tip and the inner surface of the sterilized filler nozzle with a microorganism such as a germ. In general, there is a need for disinfection of the hands, and it is practical to spray on sterilizing agent to the nozzle portion of the filler after removal of the atachment device.

However, in spite of such procedures, there has been the problem that a filling chamber may be contaminated by contacting with the environment since the shield door provided to keep the filling chamber in a sterile condition is opened to permit removing of the attachment device.

An object of the present invention is to provide an apparatus capable of conveniently heat sterilizing an entire aseptic processing and filling system including the filler which is to be in contact with the product, without causing the above-mentioned problems.

It is an object of the present invention to provide a back pressure apparatus which is adapted to be connected to the filler nozzle of the system and enables to maintain the inside of the system under a predetermined pressurization at a temperature above 1 00 C while avoiding any stagnation of the heating medium in the system.

It is another object of the present invention to provide a back pressure apparatus which is detachably connected to the filler nozzle of the system without any troublesome handling and preparatory time for the operation thereof and without destroying the sterile condition of the filler nozzle and the inside of the filler having been sterilized.

According to the present invention, it is possible to completely sterilize the inside of the system with heating medium at high temperature by connecting to the filler nozzle a cap having a flow restricting means for discharging the heating medium to maintain the pressure of the heating medium upstream of the filler nozzle of the system at a predetermined level and by passing the heating medium through the system after the connection of the cap. Furthermore, it is possible, according to the present invention, to pass the heating medium through the system without any stay thereof in the system.According to the present invention, the cap of the back pressure apparatus is designed to be compact in construction and therefore this makes it possible to convey the cap to a position directly below the filler nozzle by a conventional conveyor or the like and to connect the cap to the filler nozzle with any suitable means. By which, the mount and demount of the cap to the filler nozzle are easily carried out without destroying the sterile condition of the filler nozzle and the inside of the system.

The objects and the effects above mentioned are achieved by a back pressure apparatus of the present invention comprising a filler nozzle; a cap, positioned opposite to the filler nozzle for receiving a heating medium from the filler nozzle; means for lifting the cap toward the filler nozzle; means for achieving a sealed connection between the filler nozzle and the cap; and means in the cap, for discharging the heating medium from the system which maintaining the heating medium in the system upstream of the cap under pressurization.

Brief Description of Drawings: The present invention will become more apparent from the following description of a preferred embodiment thereof with reference to the accompanying drawings in which;, Figure 1 is a cross-sectional view of an embodiment of a back pressure apparatus attached to a filler nozzle and constructed in accordance with the present invention; Figure 2 is a view similar to Figure 1, but showing a modification of the present invention; and Figure 3 is a view similar to Figure 1 but showing a further modification of the inven ron.

Referring to Figure 1 of the drawings, there is shown a preferred embodiment of a back pressure apparatus according to the present invention comprising a cap in the form of a receiver 2 adapted to be connected to a nozzle 1 of a filler in an aseptic processing and filling system. The filler nozzle 1 extends through a fixed plate 8 below which a filling chamber is defined. A lifting device is provided for lifting the receiver 2 toward the filler nozzle 1 for connection, therewith and includes bolts 4 inserted in apertures in the fixed plate 8 and adapted to be threadedly received in tapped holes 1 2 in a flange 7 formed on the side wall of the receiver 2.

Rotation of the bolts 4 causes the receiver 2 to lift upwardly toward the filler nozzle 1 into engagement with its tip. An O-ring 5 is fitted in an annular groove in the flange 7 to form a seal between the receiver 2 and the tip of the filler nozzle 1. The receiver 2 is provided with a partition 2a for defining a compartment 2b therewithin and a conduit 2c extending from the partition through the side wall of the receiver 2 and terminating at an outlet 6.

Flow restricting means in the form of a steam trap 3 is provided in the conduit 2c within the compartment 2b of the receiver 2 to discharge heating medium such as steam from the aseptic processing and filling system through the outlet 6 to the exterior at a restricted flow rate so that the heating medium in a portion of the system upstream the receiver 2 can be maintained at a predetermined pressure.

Prior to carrying out a heat sterilization of the aseptic processing and filling system, the receiver 2 is first located on a chain conveyor 9 adapted to run through the filling chamber and to convey containers which is filled with a product during a subsequent filling operation.

The chain conveyor 9 is operated to convey the receiver 2 to a position where it is located directly below the filler nozzle 1. Then, the bolts 4 are inserted into the apertures in the fixed plate 8 to threadedly engage the tapped holes 1 2 in the flange 7 of the receiver 2. The receiver 2 is lifted upwardly toward the filler nozzle 1 by turning the bolts 4 in the tapped holes 1 2 so that it is moved away from the chain conveyor 9 until the receiver 2 sealingly engages the tip of the filler nozzle 1 with the O-ring 5 interposed therebetween.

The heat sterilization of the sterile processing and filling system is carried out by introducing a saturated steam from its source through a piping into the system and passing the steam through the filler nozzle 1 to the receiver 2 through the steam trap 3 of which the steam condensate is intermittently discharged to the exterior. The steam trap 3 in the receiver 2 serves to maintain the saturated steam in the portion of the aseptic processing and filling system upstream the steam trap 3 at a predetermined pressure required to obtain a temperature enough to sterilize the system.

The intermittent discharge of the steam condensate from the steam trap 3 through the outlet 6 permits the steam to constantly flow from the steam supply piping through the system to the filler nozzle 1. Thus, the system can be sterilized with the steam at the desired temperature for a required time of sterilization.

Upon completion of the sterilization within the system as mentioned above, the bolts 4 are loosened so that the receiver 2 can be lowered from the filler nozzle 1 to the chain conveyor 9 which is then operated to convey the receiver 2 outside of the filling chamber.

In this case, there are no possibilities of bacterial contaminating the tip of the filler nozzle 1 and its interior, and of ruining the sterilized condition within the filler because the removal and conveyance of the receiver 2 can be performed without manually handling.

In addition, a sealing device which is dis posed downstream of the filler is not in operation during the conveyance of the receiver 2, so that it is possible to convey the receiver 2 out of the filling chamber without any damages to the receiver 2 and conversely, the filler is not damaged by the receiver 2.

After the receiver 2 has been removed from the filler nozzle 1, it is necessary to remove the fastening bolts 4 from the apertures in the fixed plate 8 because these bolts 4 interfere with the incoming containers during the subsequent filling operation. In this case, it is possible to prevent bacteria or the like from entering the filling chamber through the apertures by introducing a sterilized air, an inert gas, a super heated steam thereinto to maintain the filling chamber at a positive pressure somewhat higher than the atmosphere whereby the sterilized condition therewith in can be maintained. It is preferable to close the apertures in the top plate 8 by any suitable means after removal of the bolts 4.

Although the heat-sterilization of the system with the saturated steam has been described with reference to Figure 1, a hot water from a sterilizing heater can be utilized for sterilization of the system. In this case, the steam trap 3 as shown in Figure 1, is replaced with an orifice or a throttle valve such as an orifice, a needle valve or the like. The steam drain or the hot water is discharged out of the filling chamber by connecting a pipe or the like to the outlet port 6, especially in the case where it is undesirable to discharge the steam condensate and the hot water into the filling chamber.

The conveyance of the receiver forming a part of the back pressure apparatus according to the invention may be performed by any suitable conveyor means other than the chain conveyor as described in the above embodiment. In the case where it is difficult to convey the receiver along a path of conveyance of the product containers, the chain conveyor may be reversely driven to convey the receiver through the exit side of the filling chamber to the position directly below the filler nozzle in a direction opposite to the direction of conveyance of the product containers.

Instead of the bolts threadedly received in the tapped holes in the flange of the receiver as shown in the drawings, any suitable lifter means may be employed to lift the receiver from the chain conveyor toward the filling nozzle for connection therewith.

In Figure 2 of the drawings, there is shown a cap in the form of a stainless steel plate 1 3 which is provided with tapped holes 1 2 formed therein and adapted to be threadedly engaged by the bolts 4. The plate 1 3 is also provided with a central orifice 10 forming a flow restricting means and a gasket 11 fitted in an annular groove fromed in the plate 1 3 on its upper surface. The gasket 11 serves to tightly seal between the tip of the filler nozzle 1 and the plate 1 3 when it is connected to the filler nozzle 1 by threadedly receiving the bolts 4 in the tapped holes 1 2 in the plate 1 3. There is provided a lifter 1 4 adapted to be veritcally moved through the chain conveyor 9.Prior to the connection between the filling nozzle 1 and the plate 3, the plate 1 3 is lifted by the lifter 14 toward the filling nozzle 1 to a position where the bolts are initially threaded into the tapped holes 1 2 in the plate 13.

Figure 3 shows another embodiment of the back pressure apparatus in which a cap is in the form of a receiver 2 similar to that of the first embodiment as described with reference to Figure 1 of the drawings except that the receiver 2 if brought into contact with the fixed plate 8 to surround the filler nozzle 1.

There is provided a lifter 14 similar to that shown in Figure 2 of the drawings for lifting the receiver 2 from the chain conveyor 9 toward the fixed plate 8. Gaskets of synthetic resin, rubber or the like are interposed between the periphery of the filler nozzle 1 and fixed plate 8 and between the upper end of the receiver 2 and the lower surface of the fixed plate 8, respectively to prevent any heating medium from escaping through therebetween.

The receiver may be formed from any suitable material, such as stainless steel, ceramics synthetic resin or the like which can resist the heat sterilizing operation of the system.

It will be noted from the foregoing that by connection the cap having the flow restricting means to the filler nozzle, the heating medium such as hot water or steam in the system can be maintained under the pressurization to make it possible to heat sterilize the inside of the system at the high temperature without any stagnation of the heating medium in the system. It will also be noted that the cap is simple and compact in construction and can be removably connected to the filler nozzle without any contamination of the nozzle with microorganisms and affecting the sterile condition within the system.

Claims (4)

1. A back pressure apparatus used in a sterile processing and filling system comprising a filler nozzle; a cap, positioned opposite to the filler nozzle for receiving a heating medium from the filler nozzle through the system; means for lifting the cap toward the filler nozzle; means for achieving a sealed connection between the filler nozzle and the cap; and means in the cap for discharging the heating medium from the system while maintaining the heating medium in the system upstream of the cap under pressurization.

2. A back pressure apparatus as claimed in claim 1 wherein said cap is in the form of receiver and said draining means comprises a steam trap in communication with the nozzle.

3. A back pressure apparatus as claimed in claim 1 wherein said draining means comprises an orifice formed in said cap.

4. A back pressure apparatus substantially as hereinbefore described with reference to any of Figures 1, 2 and 3 of the drawings.