NO781195L

NO781195L - METHOD OF STERILIZATION, AND ARRANGEMENTS FOR CARRYING OUT THE PROCEDURE

Info

Publication number: NO781195L
Application number: NO781195A
Authority: NO
Inventors: Nils Arne Fahlvik
Original assignee: Electrolux Ab
Priority date: 1977-04-05
Filing date: 1978-04-04
Publication date: 1978-10-06
Also published as: ATA236078A; SE7703956L; GB1555295A; IT7848675A0; AT357684B; JPS53123595A; DE2814147A1; FI781033A

Description

Fremgangsmåte ved sterilisering, samt anordning for utførelse av fremgangsmåten. Procedure for sterilisation, as well as device for carrying out the procedure.

Foreliggende oppfinnelse vedrører en fremgangsmåte for sterilisering av gjenstander med damp og derpå følgende kjøling av de steriliserte gjenstander med sirkulerende kondensvann i et sirkulasjonssystem inneholdende et kammer, som har tilførsels-ledning for damp og tilførselsledning for trykkluft, samt en ledning til enbeholder for oppsamling av kondensvann, foruten en med pumpe forsynt ledning fra beholderen til sprøytemunnstyk-kene i kammerets tak for sirkulasjon av kondensvannet i systemet. Oppfinnelsen vedrører også en autoklav for utførelse av fremgangsmåten. The present invention relates to a method for sterilizing objects with steam and then cooling the sterilized objects with circulating condensed water in a circulation system containing a chamber, which has a supply line for steam and a supply line for compressed air, as well as a line to a container for collecting condensed water , in addition to a pump-equipped line from the container to the spray nozzles in the chamber's roof for circulation of the condensed water in the system. The invention also relates to an autoclave for carrying out the method.

Når materialet i plastflasker eller ampuller steriliseres volder steriliseringen adskillige vanskeligheter p.g.a. plast-materialets egenskaper. Under varmebehandlingen, kan det dannes sprekker i flaskene hvis temperaturen blir for høy, og selv tillukkingen av flaskene kan volde lekkasje. Hitthil har man for det meste tilført særskilt vann for kjølingen etter steriliseringsperioden. Hvis dette vann ikke skal inneholde bakterier eller patogener som ved kjølingen blir igjen i de nevnte sprekkene må det spesialbehandles ved destillasjon og/eller filtrering. Ellers skjer under den følgende oppbe-varingen av flaskene en tilvekst av bakteriene, og bakterie-floraen kan vokse rakt gjennom flaskeveggen eller tillukkingen av flaskene og til materialet, som deretter ikke lenger er sterilt. When the material in plastic bottles or ampoules is sterilized, the sterilization causes several difficulties due to the properties of the plastic material. During the heat treatment, cracks can form in the bottles if the temperature gets too high, and even closing the bottles can cause leakage. Until now, separate water has mostly been added for cooling after the sterilization period. If this water is not to contain bacteria or pathogens that remain in the aforementioned cracks during cooling, it must be specially treated by distillation and/or filtration. Otherwise, during the subsequent storage of the bottles, an increase in bacteria occurs, and the bacterial flora can grow straight through the bottle wall or the closure of the bottles and into the material, which is then no longer sterile.

Foreliggende oppfinnelse vedrører å tilveiebringe en fremgangsmåte for kjøling av en atuoklav uten tilførsel av vann. utenfra og slik at bakterier ikke tilføres flaskenes utside under den på steriliseringen følgende avkjølingen. Fremgangsmåten ifølge oppfinnelsen karakteriseres således av de trinn som angis i følgende patentkrav 1. En autoklav for utførelse av fremgangsmåten karakteriseres hovedsakelig av det som angis i patentkrav 4. The present invention relates to providing a method for cooling an autoclave without supplying water. from the outside and so that bacteria are not added to the outside of the bottles during the cooling that follows sterilization. The method according to the invention is thus characterized by the steps stated in the following patent claim 1. An autoclave for carrying out the method is mainly characterized by what is stated in patent claim 4.

En fremgangsmåte og en autoklav ifølge oppfinnelsen skal be-skrives mer inngående i det følgende under henvisning til tegningen, som skjematisk viser en autoklav med kjølesystem 1 perspektiv. A method and an autoclave according to the invention will be described in more detail below with reference to the drawing, which schematically shows an autoclave with cooling system 1 in perspective.

.Autoklaven har et kammer 10 som er omgitt av en mantel 11. Kammeret 10 har en tilførselsledning 12 for damp med en proporsjonerende ventil 13, Inne i kammeret 10 ved dets bunn 14 finnes rør 15 med hull 16 tilknyttet ved en ledning 17 .The autoclave has a chamber 10 which is surrounded by a mantle 11. The chamber 10 has a supply line 12 for steam with a proportioning valve 13, Inside the chamber 10 at its bottom 14 there are tubes 15 with holes 16 connected by a line 17

til et bakteriefilter 18 i en trykkluftsledning 19 med en avstengningsventil 20 og en ikke vist bakventil. Kammeret 10 har et bunnavløp 21, som delvis ved en ledning 2 2 med _ én_.av-: stengningsventil ,23 er tilknyttet en beholder 24, og delvis.ved en med en innskrenkning 55 forsynt utblåsningsledning 56 to a bacteria filter 18 in a compressed air line 19 with a shut-off valve 20 and a back valve not shown. The chamber 10 has a bottom drain 21, which is partly connected to a container 24 by a line 22 with a shut-off valve 23, and partly by a blow-out line 56 provided with a restriction 55

leder til et ikke vist avløp. Ledningen 5 6 har også en ventil 57. leads to an unshown drain. The line 5 6 also has a valve 57.

Beholderen 24 utgjør et kondenseringskar og har en i taket sluttet ventilasjonsledning 25 med en pressostatstyrt avstengningsventil 26 og en fra bunnen gående avløpsledning 2 7 med en ventil 2 8 og en av en motor 2 9 drevet vakuumpumpe 30.'Fra denne går en trykkledning 31 til et avløp 32. Ved beholderens 24 bunn er innlagt en rørbue 33:.for et kjølemedium, . eksempelvis kaldtvann. Ved beholderens 24 bunn er dessuten tilsluttet en ledning 34/ som går til en høytrykkspumpe 35 med et arbeidstrykk mellom 20 og 50 ato. Pumpens trykkside er gjennom en ledning 3 6 tilknyttet med sprøytemunnstykker 3 7 forsynte rør 38 inne i kammeret 10 ved dennes tak og sider. Dessuten finnes ved taket inne i kammeret et med hull 39 forsynt rør 40,som gjennom en ledning 41 med ventil 42 er tilknyttet beholderens 24 øvre del. The container 24 forms a condensing vessel and has a ventilation line 25 closed in the ceiling with a pressostat-controlled shut-off valve 26 and a drain line 2 7 running from the bottom with a valve 2 8 and a vacuum pump 30 driven by a motor 2 9. From this a pressure line 31 goes to a drain 32. At the bottom of the container 24, a pipe arch 33:. for a cooling medium, . for example cold water. At the bottom of the container 24 is also connected a line 34/ which goes to a high-pressure pump 35 with a working pressure between 20 and 50 ato. The pressure side of the pump is through a line 3 6 connected to tubes 38 provided with spray nozzles 3 7 inside the chamber 10 at its roof and sides. In addition, at the roof inside the chamber there is a pipe 40 provided with a hole 39, which is connected to the upper part of the container 24 through a line 41 with a valve 42.

Et termostat 43 er anordnet med sitt følelegeme inne i beholderen 24 som også har en nivåindikator 44. A thermostat 43 is arranged with its sensor body inside the container 24 which also has a level indicator 44.

Autoklaven er ytterligere forsynt med reguleringsdon av hvilke en del vises i figuren. Et styreorgan 45 påvirker gjennom en ledning 46 dampventilen 13 og har et følelegeme 47 inne i kammeret 10. Ettetmperaturfølsomt organ 48 har en impuls-ledning 4 9 til et følelegeme 50 i en kontrollflaske 51 inne i kammeret 10. The autoclave is further equipped with regulating devices, some of which are shown in the figure. A control member 45 influences the steam valve 13 through a line 46 and has a sensing element 47 inside the chamber 10. A temperature-sensitive element 48 has an impulse line 49 to a sensing element 50 in a control bottle 51 inside the chamber 10.

Det finnes også en kjølesløyfe 52 i beholderens 24 øvre- del. Kammeret 10 har i taket en utløpsledning 53 med en ventil 54. There is also a cooling loop 52 in the upper part of the container 24. The chamber 10 has an outlet line 53 with a valve 54 in the ceiling.

Sterilisering av materiale inne i kammeret 10 gjennomføres på følgende måte. Sterilization of material inside the chamber 10 is carried out in the following way.

Materiale i flakser eller ampuller plasseres inn i autoklavkammeret 10, hvis ikke viste dør stenges. Ved start evakueres kammeret 10 med hjelp av vakuumpumpen 30 til et under-trykk av ca. 80%. Herved evakueres også kondenseringskaret 24 og samtlige rørforbindelser mellom autoklavkammeret 10, Material in flasks or ampoules is placed into the autoclave chamber 10, if not the door shown is closed. At the start, the chamber 10 is evacuated with the help of the vacuum pump 30 to a negative pressure of approx. 80%. This also evacuates the condensing vessel 24 and all pipe connections between the autoclave chamber 10,

kondenseringskaret 24 og pumpen 35. Tilførselsledningenethe condensing vessel 24 and the pump 35. The supply lines

12 og 19 for damp og trykkluft er avstengte i denne tilstand. ' 12 and 19 for steam and compressed air are closed in this state. '

Ved oppnådd vakuumverdi i kammeret 10 åpnes ventilen 13 i damptilførselsledningen 12 og damp strømmer inn delvis i kammeret 10 gjennom røret 40, som fordeler dampen jevnt over hele kammeret, delvis også direkte i beholderen 24 via ledningen 41. Avstengningsventilen 23 i ledningen 22 fra kammerets bunn stenges og samtidig begynner dampinnblåsningen. When the vacuum value in the chamber 10 is reached, the valve 13 in the steam supply line 12 is opened and steam partially flows into the chamber 10 through the pipe 40, which distributes the steam evenly over the entire chamber, partly also directly in the container 24 via the line 41. The shut-off valve 23 in the line 22 from the bottom of the chamber is closed and the steam injection starts at the same time.

Under et bestemt tidsrom, ca. 5 min., fortsetter vakuumpumpen 30 å suge. Herved fylles beholderen 24 med damp og dens temperatur høynes til ønsket verdi over 100°C. Under denne periode er hensikten å desinfisere eller sterilisere beholderen 24 innvendig. Den ønskede temperaturen kan innstilles på termostaten 43. Denne temperatur bør imidlertid ikke velges høyere enn den steriliseringstemperatur som skal gjelde for behandlingen i autoklavkammeret. During a certain period of time, approx. 5 min., the vacuum pump 30 continues to suck. The container 24 is thereby filled with steam and its temperature is raised to the desired value above 100°C. During this period, the purpose is to disinfect or sterilize the inside of the container 24. The desired temperature can be set on the thermostat 43. However, this temperature should not be chosen higher than the sterilization temperature that must apply to the treatment in the autoclave chamber.

Når termostaten 43 gir kontakt åpner ventilen 23 igjen og bunnsatsen i kammeret 10 suges ut og forsvinner via vakuum pumpen 30. Under en tidsforhaling på 1 - 2 min. fortsetter vakuumsugningen, men deretter stenges ventilen 28 og pumpen 30 stoppes. I dette øyeblikk aktiveres kjølesløyfene 33 og 52 i beholderen 24 og den damp og det kondensat som strømmer hit fra kammeret 10 og fra ledningen 3 6 mellom pumpen og kammeret kondenseres ned og avkjøles. De kondensatmengder som dannes ved den fortsatte oppvarmingen av materialet i kammeret oppsamles således i beholderen 24, likesom de ekstra dampmeng-der som tilføres gjennom ledningen 36. When the thermostat 43 makes contact, the valve 23 opens again and the sediment in the chamber 10 is sucked out and disappears via the vacuum pump 30. During a delay of 1 - 2 min. the vacuum suction continues, but then the valve 28 is closed and the pump 30 is stopped. At this moment, the cooling loops 33 and 52 in the container 24 are activated and the steam and condensate that flows here from the chamber 10 and from the line 3 6 between the pump and the chamber condenses down and cools. The amounts of condensate that are formed by the continued heating of the material in the chamber are thus collected in the container 24, as are the additional amounts of steam supplied through the line 36.

I kammeret 10 finnes minst to styre- og indikasjonsorgan for regulering av damptilførselen. Styreorganet 45 regulerer den proporsjonerende dampventilen 13 slik at en damptilførsel til-svarende den innstilte temperaturen, eksempelvis 120°C, erholdes til kammeret 10. Når kammeret 10 kommer opp til denne temperatur har materialet fortsatt en noe lavere temperatur. Det temperaturfølsomme organet 48 er derfor anordnet til å føle temperaturen i kontrollflasken 51 som tilsvarer de enheter som skal steriliseres. Først når dette organ 48 registrerer ønsket steriliseringstemperatur (120°C), erholdes signal til påbegynnelsen av steriliséringstiden. Begge føleorganene ' 45, 48 kan i særdeleshet ved større autokla-ver utvides til å reagere på flere følepunkter som innbyrdes seriekobles slik at de ønskede signalene erholdes først når samtlige punkter har oppnådd den ønskede verdi. In the chamber 10 there are at least two control and indication means for regulating the steam supply. The control member 45 regulates the proportional steam valve 13 so that a steam supply corresponding to the set temperature, for example 120°C, is obtained to the chamber 10. When the chamber 10 reaches this temperature, the material is still at a somewhat lower temperature. The temperature-sensitive member 48 is therefore arranged to sense the temperature in the control bottle 51 which corresponds to the units to be sterilized. Only when this device 48 registers the desired sterilization temperature (120°C) is a signal received for the beginning of the sterilization time. Both sensing elements '45, 48 can, in particular in the case of larger autoclaves, be expanded to react to several sensing points which are mutually connected in series so that the desired signals are obtained only when all points have reached the desired value.

Styreorganet 45 utføres vanligvis som et trykkføleorgan for at overopphetning ikke skal finne sted i det hele tatt i kammeret. Den luftmengde som kan være igjen i kammeret etter forevakuerinqsDerioden avledes suksessivt, så snart overtrykk oppnås gjennom ledningen 53 med ventilen 54, og, The control member 45 is usually designed as a pressure sensing member so that overheating does not take place at all in the chamber. The amount of air that may remain in the chamber after the pre-evacuation period is successively diverted, as soon as overpressure is achieved through the line 53 with the valve 54, and,

på den måte erholdes garanti for at kammertemperatur og trykk med ren damp i alle punkter holdes på ønsket verdi med en temperaturnøyaktighet på - 0,5°C. in this way, a guarantee is obtained that the chamber temperature and pressure with pure steam at all points are kept at the desired value with a temperature accuracy of - 0.5°C.

Når organet 4 8 starter beregningen av steriliséringstiden fortsetter damolnnblåsningen og beholderen 24 fylles suksessivt med kondensvann til det nivå som bestemmes av indi-katoren 44. Herved stenges ventilen 23 i ledningen 22 fra bunnavløpet 21. Kjøleeffekten i beholderen 24 økes gjennom sløyfen 33 slik at temperaturen på kort tid kan senkes til maksimalt 20°C. When the device 48 starts the calculation of the sterilization time, the dam cloud blowing continues and the container 24 is successively filled with condensed water to the level determined by the indicator 44. This closes the valve 23 in the line 22 from the bottom drain 21. The cooling effect in the container 24 is increased through the loop 33 so that the temperature in a short time can be lowered to a maximum of 20°C.

Ved avsluttet sterilisering stenges dampventilen 13 og samtidig åpnes ventilen 20 for tilførsel av sterilfiltrert trykkluft. Denne lufttilførsel pressostatstyres til samme overtrykk som holdes under dampsteriliséringen. When sterilization is finished, the steam valve 13 is closed and at the same time the valve 20 is opened for the supply of sterile filtered compressed air. This air supply is controlled by a pressostat to the same excess pressure as is maintained during steam sterilisation.

Samtidig starter høytrykkspumpen 3 5 og trykker kjølevann fra beholderen 24 gjennom diffunderingsmunnstykkene 37 inn i kammeret 10. Disse munnstykkene 37 har hvert og et en kapasitet av ca. 0,5 l/min. og finfordeler kjølevannet i tåkeform jevnt over hele materialmengden i kammeret. Ventilen 23 i ledningen 22 fra bunnavløpet 21 åpnes i denne tilstand, slik at kjølevann kan renne tilbake til beholderen 24. At the same time, the high-pressure pump 35 starts and pushes cooling water from the container 24 through the diffusion nozzles 37 into the chamber 10. These nozzles 37 each have a capacity of approx. 0.5 l/min. and finely distributes the cooling water in mist form evenly over the entire amount of material in the chamber. The valve 23 in the line 22 from the bottom drain 21 is opened in this state, so that cooling water can flow back to the container 24.

Den gjennom røret 15 innblåste trykkluften avledes gjennom takrøret 40 ned til beholderen 24. Her har den pressostat-styrte avstengningsventilen 26 blitt åpnet, slik at over-skuddsluft utblåses. Den mot steriliseringsmaterialet inn-sprøytede kalde vanntåke binder varme fra flaskene eller ampullene og fordampes raskt. Trykkluften som innblåses nedenfra tar med seg den dannede damp og fører den bort gjennom takrøret 40 og ledningen 41 til beholderen 24. Dampen kondenseres her mot kjølesløyfen 52 i beholderens over-del og luften går bort gjennom ventilen 26. Ikke fordampet kjølevann renner av gjennom ventilen 23 og rørledningen 22 til beholderen 24. The compressed air blown in through the pipe 15 is diverted through the roof pipe 40 down to the container 24. Here, the pressostat-controlled shut-off valve 26 has been opened, so that excess air is blown out. The cold water mist sprayed onto the sterilization material binds heat from the bottles or ampoules and evaporates quickly. The compressed air that is blown in from below takes the formed steam with it and carries it away through the roof pipe 40 and the line 41 to the container 24. The steam is condensed here against the cooling loop 52 in the upper part of the container and the air leaves through the valve 26. Non-evaporated cooling water drains off through the valve 23 and the pipeline 22 to the container 24.

Gennom fordampningen av' kjølemediet erholdes en meget rask varmebortgang fra steriliseringsmaterialet og en kort nedkjø-lingstid, eksempelvis ca. 30 min. for halvlitersampuller fra 120 - 40°C. Through the evaporation of the refrigerant, a very rapid heat loss from the sterilizing material and a short cooling time, for example approx. 30 min. for half-liter ampoules from 120 - 40°C.

Kjølingen med vanntåke og gjennomblåsning av luft får fort-sette til ønsket sluttemperatur oppnås, hvilken indikeres av det temperaturfølsomme organet 48. Da brytes prosessen. Lufttilførselen og kjølemediepumpen stoppes. Ventilen 23 stenges, og avblåsning skjer gjennom ventilen 26 inntil trykk-balanse med ytterluften oppnås. The cooling with water mist and blowing of air is allowed to continue until the desired final temperature is reached, which is indicated by the temperature-sensitive member 48. The process is then interrupted. The air supply and the refrigerant pump are stopped. Valve 23 is closed, and blow-off takes place through valve 26 until pressure balance with the outside air is achieved.

Claims

1.' Method for sterilization of objects with steam and subsequent cooling of the sterilized objects with circulating condensed water in a circulation system containing a chamber, which has a supply line for steam and a supply line for compressed air, as well as a line to a container for collecting condensed water in addition to one with a pump provided line from the container to the spray nozzles in the roof of the chamber for circulation of the condensed water in the system, characterized by the following steps: a) air in the system is evacuated with a suction pump (30) connected to the container (24) b) steam is supplied to the autoclave chamber (10) and container (24) to raise the temperature up to sterilization temperature c) air and condensate that forms in the chamber (10) is sucked out of it with the pump (30) d) when sterilization temperature is reached in the container (24), a valve (28) in a line (27) from the container (24) to the pump (30) is closed and the suction is terminated. e) steam is blown through the chamber (10) to the container (24) to maintain pressure and temperature for sterilization in the chamber (10), steam is condensed down and the condensate is cooled in the container (24) f) in the container (24) a certain amount of condensate is collected during simultaneous sterilization of the objects in the chamber (10) g) during the last part of the sterilization time, the connection (22) from the chamber (10) to the container (24) is closed and blow-off is done to a limited extent through a direct outlet (55, 56, 57) from the chamber (10) to a drainage h) the water in the container (24) is cooled to approx. 20°C i) sterile compressed air is blown into the chamber from below (10) j) the water in the container (24) is blown under high pressure into the chamber (10) through special diffusion nozzles (37) so that a finely distributed mist of water is obtained k) the air stream coming from below in the chamber (10) is brought to carry the steam formed through condensation of the water mist through loops (39, 40) in the chamber ceiling and via a line (41) to the container (24), where the steam is cooled to condensation and the residual air is released via a valve (26) m) finally pressure equalization is done with sterile air to atmospheric pressure in the chamber (10).

2. Method according to claim 1, characterized in that the water in the container is blown into the chamber by means of a high-pressure pump which works at a pressure between 20 and 50 ato.

3. Method according to claim 1, characterized in that during the cooling period the blowing in of sterile compressed air is regulated depending on the pressure in the chamber with a valve (20) in a line (19) for supplying compressed air to the chamber.

4. Autoclave for carrying out the method according to claim 1 with a circulation system containing a chamber that has a supply line for steam and a supply line for compressed air, as well as a line to a container for collecting condensed water in addition to a line equipped with a pump from the container to the spray nozzle in the roof of the chamber for circulation of the condensed water in the system, characterized in that the container (24) has a cooling device (33, 52) and a drain line (27) connected at the bottom and provided with a valve (20) and vacuum pump (30) and that the line (22) ) from the chamber (10) to the container (24) has a valve (23), and that a connecting line (41) is arranged from the upper part of the chamber (10) to the upper part of the container (24) where the chamber (10) has a drain (56) provided with a valve (57) and further that a high-pressure pump (35) is included in the circulation line (36) between the container (24) and the chamber (10).

5. Autoclave according to claim 4, characterized in that the high-pressure pump (35) is arranged to provide a pressure between 20 and 50 ato.

6. Autoclave according to claim 4, characterized in that the container (24) has a ventilation line (25) provided with a pressostat-controlled valve (2.6) for the removal of air.

7. Autoclave according to claim 4 or 5, characterized in that the container (24) has an adjustable, level-sensing member (44) which is arranged to close a valve (23) in the line (22) when the condensate reaches the level ) between the chamber (10) and the container (24) and instead open a valve (57) in the drain (56) from the chamber (10).

8. Autoclave according to claims 4-7, characterized in that the valve (28) of the drain line (27) is connected to a control device which is arranged to keep the valve (28) open during heating of the chamber (10) until a certain temperature is reached therein.

9. Autoclave according to claims 4-8, characterized in that the valve (20) of the compressed air line (19) is arranged to regulate the pressure during cooling in the chamber (10) air is supplied to the seal depending on the pressure in the chamber.

10. Autoclave according to claim 9, characterized in that the compressed air line (19) is connected to a ramp (15) with a hole (16) at the bottom of the chamber (10) and that there is a ramp (40) at the roof of the chamber (10) which is connected to the connection line (41).