Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J3/00—Processes of utilising sub-atmospheric or super-atmospheric pressure to effect chemical or physical change of matter; Apparatus therefor
  • B01J3/04—Pressure vessels, e.g. autoclaves
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L2/00—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L2/00—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor
  • A61L2/02—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor using physical phenomena
  • A61L2/04—Heat
  • A61L2/06—Hot gas
  • A61L2/07—Steam
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J3/00—Processes of utilising sub-atmospheric or super-atmospheric pressure to effect chemical or physical change of matter; Apparatus therefor

Definitions

• the present invention refers to a sterilization chamber for autoclaves and of the type in which the sterilization process incorporates treatment of the goods to be sterilized with alternating temperature and pressure variations, with the pressure varying between overpressure and vacuum suction, and which is provided with a wall structure incorporating an inner wall and an outer wall arranged spaced apart therefrom, whereby an intermediate space is formed between the two walls.
• Autoclaves are used for sterilization of different types of goods, e.g. surgical and dental instruments, whereby the goods during a short period of time shall be heated with water steam to a high temperature, usually 134°C and at a pressure of 2.1 bar. The goods shall furthermore be subjected to vacuum.
• the sterilization chamber hereby is subjected to two contradictory requirements. It must have low heat capacity (kWs/kg degree), low heat conductivity (W/m degree) and it furthermore shall be strong. Due to the internal subpressure, which must be established in connection with the vacuum treatment of the goods, it is required that the sterilization chamber has thick walls, thus that it can withstand the internal subpressure without buckling.
• the purpose of the present invention is to provide a sterilization chamber of the type mentioned in the introduction, which can have a thinner inner wall of high tensile steel compared to what has earlier been possible, at the same time as the requirement for a thick layer of insulation material is reduced, and this has been achieved in that said space between the walls of the chamber have a constant vacuum, which is lower than the lowest treatment pressure for which the sterilization chamber is intended, in order primarily to ascertain that the inner wall is not subjected to an internal subpressure and secondly for contributing to the heat insulation.
• the figure shows in cross section a non-limiting embodiment of a sterilization chamber according to the invention, whereby the chamber has been shown without associated connections for vacuum, steam, cooling medium, etcetera.
• the sterilization chamber 1 incorporates a strong outer wall 12, e.g. from structural steel, and in the embodiment shown shaped as a cylinder, which is closed off at one end by a dome-shaped portion, an inner wall of stainless, but considerably thinner material than the outer wall, and which inner wall is received inside the outer wall 2, thus that an intermediate space 4 is formed between inner wall 3 and outer wall 2.
• the open end of the sterilization chamber rests against a planar, strong end wall 5 of substantially circular form, with a thin planar inner wall 6, provided at a distance from the outer end wall 5 and for increasing the load carrying capacity and the insulating power, the space between the end wall 5 and the inner wall 6, in the embodiment shown, is filled with an insulation 7, which has been subjected to vacuum suction.
• a seal 8 positioned in a groove, here illustrated as a sealing ring having a circular cross section.
• the intermediate space 4 between the inner wall 3 and the outer wall 2 of the chamber prevails a permanent, constant vacuum, which, when this space, in connection with the manufacture of the chamber, is hermetically sealed off, can be set to a level below the lowest pressure (subpressure) to which the interior of the sterilization chamber will be subjected in connection with the vacuum suction involved in the sterilization process, and this vacuum in the intermediate space will efficiently ascertain that the interior of the inner wall 3 never will be subjected to an overpressure acting from within and outwards in relation to the pressure in the intermediate space 4, i.e. also during vacuum suction of the interior of the sterilization chamber.
• subpressure the lowest pressure
• the inner wall 3 never will be subjected to an inner subpressure, the risk for this inner wall to buckle inwardly is not at hand, and from strength aspects the inner wall 3 therefore can be made rather thin.
• the outer wall 2 on the other hand must be made thicker as it will be acted upon from within by the negative pressure difference, which is at hand between the intermediate space 4 and the surrounding atmosphere.
• the entire chamber will operate as a vacuum insulated thermos, preferably at a pressure below 10 "2 mbar, which gives a good heat insulation only as a consequence of this low vacuum.
• the intermediate space 4 between these curved wall sections can preferably also be provided with a (not shown) heat insulation. It has proven itself that the insulating materials used reduces their heat conductivity considerably in vacuum of the levels, which are constantly at hand in the space 4.
• insulating materials can be mentioned, e.g. MICROTHERM, a microporous heat insulating material, or the porous fibre silicate board SUPRATHERM "L", which is marketed by the company Brandenburger Isoliertechnik GmbH % Co K.G..
• MICROTHERM a microporous heat insulating material
• SUPRATHERM "L” a microporous heat insulating material
• Another appropriate material can be the hard glass fibre fabric BRA-GLA, which is also marketed by Brandenburger Isoliertechnik.
• this lastmentioned material can be designed as a screen pattern, preferably in the form of a honeycomb structure. If this material has a heat conductivity of 0,22 W/mK it is possible to make high strength structures with a heat conductivity of about 0,0022 W/mK if a vacuum is at hand in the cavities of the honeycomb structure.

Landscapes

• Health & Medical Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Epidemiology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Apparatus For Disinfection Or Sterilisation (AREA)
• Food Preservation Except Freezing, Refrigeration, And Drying (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20403048

Family Applications (1)

Country Status (8)

Cited By (2)

Citations (1)

• 1996
  • 1996-06-18 SE SE9602397A patent/SE506524C2/sv not_active IP Right Cessation
• 1997
  • 1997-06-16 PL PL97330733A patent/PL330733A1/xx unknown
  • 1997-06-16 WO PCT/SE1997/001051 patent/WO1997048420A1/en not_active Application Discontinuation
  • 1997-06-16 JP JP10502792A patent/JP2000513958A/ja active Pending
  • 1997-06-16 BR BR9709739A patent/BR9709739A/pt not_active Application Discontinuation
  • 1997-06-16 KR KR1019980710421A patent/KR20000016809A/ko not_active Application Discontinuation
  • 1997-06-16 EP EP97928591A patent/EP0923384A1/de not_active Withdrawn
  • 1997-06-16 AU AU32810/97A patent/AU3281097A/en not_active Abandoned

Patent Citations (1)

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