GB1577602A - Creation of Inventions and Patents with Artificial Intelligence

GB1577602A – Method and apparatus for the sterilization of heat resistant objects
– Google Patents

GB1577602A – Method and apparatus for the sterilization of heat resistant objects
– Google Patents
Method and apparatus for the sterilization of heat resistant objects

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Publication number
GB1577602A

GB1577602A
GB29182/77A
GB2918277A
GB1577602A
GB 1577602 A
GB1577602 A
GB 1577602A
GB 29182/77 A
GB29182/77 A
GB 29182/77A
GB 2918277 A
GB2918277 A
GB 2918277A
GB 1577602 A
GB1577602 A
GB 1577602A
Authority
GB
United Kingdom
Prior art keywords
air
furnace
objects
current
sterilization
Prior art date
1976-07-13
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)

Expired

Application number
GB29182/77A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

Bayer AG

Original Assignee
Bayer AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
1976-07-13
Filing date
1977-07-12
Publication date
1980-10-29

1977-07-12
Application filed by Bayer AG
filed
Critical
Bayer AG

1980-10-29
Publication of GB1577602A
publication
Critical
patent/GB1577602A/en

Status
Expired
legal-status
Critical
Current

Links

Espacenet

Global Dossier

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230000001954
sterilising effect
Effects

0.000
title
claims
description
27

238000004659
sterilization and disinfection
Methods

0.000
title
claims
description
27

238000000034
method
Methods

0.000
title
claims
description
13

238000001816
cooling
Methods

0.000
claims
description
28

239000002245
particle
Substances

0.000
claims
description
23

241000605281
Anaplasma phagocytophilum
Species

0.000
claims
1

239000011521
glass
Substances

0.000
description
5

239000003365
glass fiber
Substances

0.000
description
3

238000010438
heat treatment
Methods

0.000
description
3

239000000428
dust
Substances

0.000
description
2

238000005265
energy consumption
Methods

0.000
description
2

238000005259
measurement
Methods

0.000
description
2

238000009827
uniform distribution
Methods

0.000
description
2

239000007795
chemical reaction product
Substances

0.000
description
1

239000003814
drug
Substances

0.000
description
1

229940079593
drug
Drugs

0.000
description
1

238000001914
filtration
Methods

0.000
description
1

239000000463
material
Substances

0.000
description
1

239000002184
metal
Substances

0.000
description
1

238000005192
partition
Methods

0.000
description
1

239000000825
pharmaceutical preparation
Substances

0.000
description
1

239000004417
polycarbonate
Substances

0.000
description
1

230000001105
regulatory effect
Effects

0.000
description
1

230000009897
systematic effect
Effects

0.000
description
1

Classifications

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

A61L2/08—Radiation

Description

PATENT SPECIFICATION
( 21) Application No 29182/77 ( 2:
( 31) Convention Application No 263 ( 32) Filed 13 July 1976 in ( 33) Federal Republic of Germany ( ( 44) Complete Specification publishe ( 51) INT CL 3 F 27 B 9/00 9/04 ( 52) Index at acceptance F 4 B A 5 A A 5 B I A 5 E 3 A CX 2) Filed 12 July 1352 DE) d 29 Oct 1980 ( 11) 1 577 602 1977 ( 54) METHOD AND APPARATUS FOR THE STERILIZATION OF HEAT RESISTANT OBJECTS ( 71) We, BAYER AKTIENGESELLSHAFT, a body corporate organised under the laws of the Federal Republic of Germany, of 509 Leverkusen, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:-
The invention relates to a process and apparatus for the sterilization of heat resistant objects, such as glass bottles for parenteral drugs and other containers The objects are continuously sterilized by radiant heat in a continuous heating furnace and then cooled by a blast of air The cooling air used for this purpose is filtered in high power filters for suspended materials (HEPA filters).
Glass containers used in the pharmaceutical industry for pharmaceutical preparations must be carefully sterilized.
For this purpose, the containers are continuously passed through a radiant heat furnace on shelves or conveyor belts.
Systematic measurements with particle counters have shown that in the absence of special measures a radiant furnace contains a high proportion of foreign particles, e g.
dust Up to 104 particles having an average diameter of more than 0 5 rum have been found in a litre of air It is obvious that such a high concentration of foreign particles causes a high wastage rate in the end products of the process The so-called laminar flow principle is therefore employed, in which streams of highly purified air of low turbulence are produced at the inlet and outlet end of the radiant furnace at right angles to the direction of movement of the containers (see, for example, German Auslegeschrift No.
1 936865) Blowers are normally used to produce the air streams The air is purified by high power filters for suspended particles immediately before it enters the furnace.
These filters are known as HEPA filters and are generally made of non-woven glass fibre webs By means of this apparatus it is possible to reduce the particle count in the sterilization tunnel and in the adjacent inlet and outlet zones to a value conforming to the US Federal Standard 209 b The particle counts measured in the whole region of the sterilization tunnel are of the order of I particle > 0 5 pum per litre of air However, when the above mentioned sterilization apparatus with HEPA filters are used at the inlet and outlet zones and within the sterilization zone, the purity of air is obtained at the expense of very high cost of apparatus.
It is an object of the present invention to provide a method of low particle sterilization which is more economical in its investment costs and energy consumption.
The term “low particle” means that the particle count conforms at least to the requirements laid down in the US Federal Standard 209 b, requiring not more than 3 5 particles > 0 5 Mtm per litre of air.
According to the invention, there is provided a process for the sterilization of heat resistant objects, comprising passing the objects through a continuous furnace in which they are sterilized by radiant heat through which furnace a low turbulence current of air having a low particle count (as herein defined) is passed parallel to the direction of movement of the objects and subsequently cooling the objects by means of air having a low particle count.
The low turbulence current is advantageously produced by a pressure gradient in the cooling zone following the exit from the furnace and the sterilization zone In this way, a small portion of the cooling air which has been filtered through a HEPA filter is branched off from the cooling zone and flows over the containers from the furnace outlet to the furnace inlet against the direction of movement of the containers The pressure gradient is preferably adjusted so that the transverse 0 C 1,577,602 current in the furnace has a velocity of from 0.2 to 0 7 m/sec.
A preferred embodiment of the invention is characterised in that the current of air is removed practically entirely by suction through an inlet gate at the entrance to the furnace.
According to the invention, there is also provided an apparatus for the sterilization of heat resistant objects, comprising a radiant heated tunnel furnace, a conveyor for continuously conveying the objects through the furnace, an inlet gate at the inlet end of the furnace comprising an air supply box connected to a blower, the height of which box above the conveyor is infinitely variably adjustable and an air withdrawal box below the conveyor connected to a blower, a cooling zone at the outlet from the furnace, at least one blower and a filter for suspended particles for supplying filtered air to the cooling zone, and at least one blower for withdrawing air from the cooling zone, all of said blowers being infinitely variably adjustable, so that the velocity of a current of air through the furnace is adjustable Adjustable shutters may be provided between the furnace outlet and the cooling zone and between the cooling zone and the sterile zone In addition, the air supply distributor of the inlet gate is infinitely variably adjustable in its height The transverse current can therefore be regulated reproducibly with great accuracy.
The following advantages are achieved by the invention:
1 The standard of purity required by US Federal Standard 209 b can be maintained throughout the entire furnace space.
Measurements with a Royco particle counter manufactured by Bausch & Lomb showed that over long periods of time a particle concentration of about 1 particle > 0 5 sum per litre of air was maintained throughout the radiant furnace.
2 No HEPA filters or blowers are required in the sterilization zone This reduces the initial cost of the plant and the energy consumption.
3 The plant is easier to maintain because the sterilization zone is more easily accessible.
4 The excess pressure may safely be reduced, starting from the sterile zone to the outlet of the radiant furnace.
Another important advantage is that the HEPA filters used need not be refractory since they are not fed with heated air but only with air from the surrounding atmosphere It is therefore possible to use HEPA filters made of organic fibres, which are preferable to glass fibre filters for medical and health reasons.
6 Glass fibre HEPA filters also have the disadvantage that they require relatively narrow temperature tolerances to be observed in the high temperature region If HEPA filters are used within the sterilization zone and operated with hot air, complicated control devices are required to keep the temperature constant within the given narrow tolerances In the process according to the invention, on the other hand, temperature control is not critical and need merely be maintained within a range of 300 to 3200 C.
7 The high temperatures which can be reached in the sterilization zone ensure substantial depyrogenisation of the objects passing through it.
An example of the invention will now be described in more detail with reference to the drawings in which Figure 1 is a schematic representation of the sterilization plant, and Figure 2 represents the sterilization plant with the directions of flow indicated in arrows.
The sterilization apparatus shown in Figure 1 consists basically of four zones, an inlet zone 1, a sterilization zone 2, a cooling zone 3 and an outlet zone 4 The inlet zone 1 is at normal pressure The outlet zone 4 is at an excess pressure of 124 6 pbar to conform to the adjacent sterile zone The sterilization zone 2 is shielded off at the inlet and outlet by so-called laminar flow units 5 and 6 They consist of a blower 7 and 8, respectively, with a HEPA filter 9 and 10 below it These devices produce a curtain of filtered air through which the containers pass at the inlet and outlet The sterilization zone 2 proper consists of a radiant heating furnace 11 with heating rods 12.
The glass bottles which are to be sterilized are passed through the radiant furnace 11 on a conveyor belt 13 The furnace temperature is normally in the region of 300 to 3200 C The rate of transport is approximately 0 1 metre per minute An inlet gate 14 is arranged at the furnace inlet It is formed by two boxes 15 placed opposite each other and having air outlet apertures and suction apertures The upper of the two boxes is capable of infinitely variable adjustment in height Uniform distribution of air is achieved, for example, by using a perforated metal sheet for the undersurface of the air supply box or the top of the air discharge box In addition to the air curtain at the inlet end 1, another air curtain of filtered air is produced perpendicularly to the conveyor belt 13 in the region of the boxes 15 This curtain is produced by means of a blower 16 Since the inlet gate 14 already provides for uniform distribution of air, a HEPA filter 17 may be arranged outside the radiant furnace 1,577,602 11 if the pipes carrying the filtered air do not contaminate it with particles.
The cooling zone 3 is adjacent to the outlet from the radiant furnace 11 The sterilized containers leaving the furnace are cooled to approximately room temperature in this region The cooling zone 3 shown here is equipped with two blowers 19 and These blowers are analogous to the laminar flow unit 5 and the air supply of the inlet gate 14 in producing a current of low turbulence perpendicular to the conveyor belt 13 HEPA filters 21 are again provided between the blowers 19 and 20 and the conveyor belt 13 A reservoir 22 communicating with a blower 23 to suck off the cooling air is situated underneath the conveyor belt 13 in the region of the cooling zone 3 This reservoir 22 produces a uniform flow profile in the cooling zone 3.
Adjustable shutters 24 and 25 are provided at the outlet of the furnace 11 and at the end of the cooling zone 3 They consist of substantially rectangular baffle plates adjustable in height and they partition off the sterilization zone 2 and cooling zone 3.
The smallest permissible width of gap is the height of the containers to be sterilized.
All the HEPA filters 9, 10, 17 and 21 are at room temperature They may be made of non-woven webs of poly-carbonate fibres which have a degree of filtration of more than 9990 for dust particles above 0 5 tum.
Figure 2 shows the conditions of flow in the sterilization zone 2, the cooling zone 3 and the outlet zone 4 The speeds of rotation of the blowers 16, 18, 19, 20 and 23 are infinitely adjustable The exhaust air fan 23 in the cooling zone 3 is first adjusted so that the portion of air which is drawn into the cooling zone from the outlet zone 4 by the excess pressure in the sterile zone is removed by the fan 23 A portion of the air supplied by the blowers 19 and 20 is thereby caused to flow through the shutter 24 into the furnace 11 against the direction of movement of the containers and is removed by the exhaust air fan 18 at the furnace inlet.
The output of the fan 18 must therefore be higher by this amount than that of the corresponding air supply blower 16 in order to remove the partial stream flowing through the furnace Coarse adjustment of this partial stream is effected by adjusting the blowers 16, 18, 19, 20 and 23 while fine adjustment is obtained by means of the shutters 24 and 25 Optimum conditions of purity in the radiant furnace 11 are obtained when the rate of flow of the current of air is within the range of from 0 2 to 0 7 m/sec.
Since this range is relatively wide, no complicated control devices are required to keep the flow velocity of the current of air constant.
The glass bottles to be sterilized are in many cases still wet when they enter the sterilization zone if they have previously been washed and rinsed Due to the high temperatures in the furnace, they dry very rapidly in the first section of the furnace.
The steam thereby produced is removed by the fan 18 which is for this reason referred to as the wet exhaust air fan Sterilization takes place in the parts of the furnace 11 which are further downstream.
Example
Glass bottles were sterilized under the following operating conditions:
Pressure in outlet zone =Pressure in sterile zone Pressure in cooling zone 3 above the conveyor belt in the reservoir 22 Pressure in radiant furnace 1 l(middle) Pressure at inlet to radiant furnace 11 = 124 6,ubar = 20 pbar =-30 pbar = pbar = 20 Mbar Under these pressure conditions, a transverse current flowing at a velocity of v.= 0 2 m/sec is established in the radiant furnace.

Claims (8)

WHAT WE CLAIM IS:-

1 A process for the sterilization of heat resistant objects, comprising passing the objects through a continuous furnace in which they are sterilized by radiant heat through which furnace a low turbulence current of air having a low particle count (as herein defined) is passed parallel to the direction of movement of the objects and subsequently cooling the objects by means of air having a low particle count.

2 A process as claimed in claim 1, wherein the current of air is counter-current to the direction of movement of the objects through the furnace.

3 A process as claimed in claim I or 2, wherein the velocity of the current of air is from 0 2 to 0 7 m/sec.

4 A process as claimed in claim 2 or 3, wherein the current of air is substantially entirely withdrawn for the furnace at the inlet thereto.

A process substantially as herein described with reference to the accompanying drawings.

6 An apparatus for the sterilization of heat resistant objects, comprising a radiant heated tunnel furnace, a conveyor for continuously conveying the objects through the furnace, an inlet gate at the inlet end of the furnace comprising an air supply box connected to a blower, the height of which box above the conveyor is infinitely variably adjustable and an air withdrawal box below the conveyor connected to a blower, a 1,577,602 cooling zone at the outlet from the furnace, at least one blower and a filter for suspended particles for supplying filtered air to the cooling zone, and at least one blower for withdrawing air from the cooling zone, all of said blowers being infinitely variably adjustable, so that the velocity of a current of air through the furnace is adjustable.

7 An apparatus as claimed in claim 6, further comprising adjustable slit shutters arranged between the cooling zone and the furnace outlet and between the cooling zone and a sterile zone for fine adjustment of said air velocity.

8 An apparatus substantially as herein described with reference to the accompanying drawings.
ELKINGTON AND FIFE, Chartered Patent Agents, High Holborn House, 52/54 High Holborn, London, WCIV 65 H.
Agents for the Applicants.
Printed for Her Majesty’s Stationery Office, by the Courier Press Leamington Spa 19 X O Published by The Patent Office, 25 Southampton Buildings, London WC 2 A l AY, from which copies may be obtained.

GB29182/77A
1976-07-13
1977-07-12
Method and apparatus for the sterilization of heat resistant objects

Expired

GB1577602A
(en)

Applications Claiming Priority (1)

Application Number
Priority Date
Filing Date
Title

DE2631352A

DE2631352C3
(en)

1976-07-13
1976-07-13

Process for low-particle sterilization

Publications (1)

Publication Number
Publication Date

GB1577602A
true

GB1577602A
(en)

1980-10-29

Family
ID=5982828
Family Applications (1)

Application Number
Title
Priority Date
Filing Date

GB29182/77A
Expired

GB1577602A
(en)

1976-07-13
1977-07-12
Method and apparatus for the sterilization of heat resistant objects

Country Status (11)

Country
Link

US
(1)

US4140479A
(en)

JP
(1)

JPS539092A
(en)

CA
(1)

CA1068065A
(en)

CH
(1)

CH618607A5
(en)

DE
(1)

DE2631352C3
(en)

DK
(1)

DK315977A
(en)

ES
(1)

ES460650A1
(en)

FR
(1)

FR2358163A1
(en)

GB
(1)

GB1577602A
(en)

NL
(1)

NL7707699A
(en)

SE
(1)

SE7708096L
(en)

Families Citing this family (18)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

JPS5578966A
(en)

1978-12-12
1980-06-14
Kato Yoshihisa
Pulverizing treatment method of appliances for medical treatment and its device

DE2919015A1
(en)

1979-05-11
1980-11-20
Ammann Siegfried
Sterile container filling station – applying two blasts of steam air mixture and two of hot dry air

US4412849A
(en)

1981-04-09
1983-11-01
Klenzaids Engineers Private Limited
Method and apparatus for control of gas-borne particulates

DE3321195A1
(en)

1983-06-11
1984-12-13
Bayer Ag, 5090 Leverkusen
Device for the dry heat sterilisation of glass vessels for medicaments for parenteral use

JPS611991A
(en)

1984-06-14
1986-01-07
東陶機器株式会社
Tunnel-kiln preheating zone kiln-operating method

DE3506788A1
(en)

1985-02-22
1985-07-18
Detlef 1000 Berlin Güttschow
Method of continuously measuring and controlling the temperature course of containers and accessories for parenteral drugs

DE3510286A1
(en)

1985-03-19
1986-09-25
Hans Gilowy Maschinenfabrik “Meteorwerk” GmbH & Co, 1000 Berlin
Method of operating radiation sterilisation apparatus and a device for carrying out the method

DE3701915A1
(en)

1987-01-23
1988-08-04
Finnah Gmbh
Method and machine for the sterile packaging of products in containers

DE3734830A1
(en)

1987-10-14
1989-04-27
Gilowy Hans Maschf

METHOD FOR STERILIZING TEMPERATURE-RESERVABLE CONTAINERS UNDER CLEAN ROOM CONDITIONS

US4846669A
(en)

1988-05-13
1989-07-11
Despatch Industries, Inc.
Continuous material heating oven

US4988288A
(en)

1988-05-13
1991-01-29
Despatch Industries, Inc.
Material heating oven

DE4217054A1
(en)

1992-05-22
1993-11-25
Bausch & Stroebel Maschf

Sterilization tunnel

DE4233834C1
(en)

1992-10-05
1993-11-04
Gilowy Hans Maschf
Tunnel oven obviating gathering of residual material – involves push beams in oven inlet and outlet operable from outside and transporting residual material outwards

US5958336A
(en)

1996-04-26
1999-09-28
Duarte; Raul
Surface sterilization device

DE19709067A1
(en)

1997-03-06
1998-09-17
Bosch Gmbh Robert

Procedure for controlling the air speed in a sterilization tunnel during the heating phase

KR100229138B1
(en)

1997-03-22
1999-11-01
윤종용
A filter in microwave oven

DE19726222A1
(en)

1997-06-20
1998-12-24
Bosch Gmbh Robert
Assembly to sterilise, fill and seal containers

CL2011000042A1
(en)

2011-01-07
2011-06-17

Fortification system comprising a standard helical bar, an expansion head adapted to the thread of the bar, an element of plastic material, a corrugated plastic tube, a standard fortification plate and a threaded fortification nut according to the helical bolt that use.

Family Cites Families (6)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

CH345260A
(en)

1957-06-19
1960-03-15
Jovignot Raymond

Process for placing a previously sterilized product in sterile containers under sterile conditions and installation for carrying out the process

US2950098A
(en)

1958-04-22
1960-08-23
Catalytic Comb Corp
Coating oven

DE1936865C3
(en)

1969-07-19
1974-04-25
Farbwerke Hoechst Ag, Vormals Meister Lucius & Bruening, 6000 Frankfurt

Hot air tempering and sterilizing device

DE2035822C3
(en)

1970-07-18
1978-04-06
Hoechst Ag, 6000 Frankfurt

Method and device for sterilizing containers for pharmaceutical preparations by flaming

FR2247388B1
(en)

1973-10-12
1977-08-05
Anrep Rene

US3869249A
(en)

1974-03-22
1975-03-04
Indian Head Inc
Curing oven

1976

1976-07-13
DE
DE2631352A
patent/DE2631352C3/en
not_active
Expired

1977

1977-06-21
US
US05/808,584
patent/US4140479A/en
not_active
Expired – Lifetime

1977-07-11
CA
CA282,392A
patent/CA1068065A/en
not_active
Expired

1977-07-11
NL
NL7707699A
patent/NL7707699A/en
not_active
Application Discontinuation

1977-07-11
JP
JP8209377A
patent/JPS539092A/en
active
Pending

1977-07-12
SE
SE7708096A
patent/SE7708096L/en
unknown

1977-07-12
ES
ES460650A
patent/ES460650A1/en
not_active
Expired

1977-07-12
DK
DK315977A
patent/DK315977A/en
unknown

1977-07-12
CH
CH861077A
patent/CH618607A5/de
not_active
IP Right Cessation

1977-07-12
GB
GB29182/77A
patent/GB1577602A/en
not_active
Expired

1977-07-13
FR
FR7721787A
patent/FR2358163A1/en
not_active
Withdrawn

Also Published As

Publication number
Publication date

NL7707699A
(en)

1978-01-17

ES460650A1
(en)

1978-11-16

CA1068065A
(en)

1979-12-18

FR2358163A1
(en)

1978-02-10

DK315977A
(en)

1978-01-14

DE2631352A1
(en)

1978-02-02

DE2631352C3
(en)

1983-02-17

US4140479A
(en)

1979-02-20

DE2631352B2
(en)

1979-03-15

JPS539092A
(en)

1978-01-27

SE7708096L
(en)

1978-01-14

CH618607A5
(en)

1980-08-15

Contact information