CA2080349A1 - Process and unit for disinfection and sterilisation of infectious waste - Google Patents
Process and unit for disinfection and sterilisation of infectious wasteInfo
- Publication number
- CA2080349A1 CA2080349A1 CA002080349A CA2080349A CA2080349A1 CA 2080349 A1 CA2080349 A1 CA 2080349A1 CA 002080349 A CA002080349 A CA 002080349A CA 2080349 A CA2080349 A CA 2080349A CA 2080349 A1 CA2080349 A1 CA 2080349A1
- Authority
- CA
- Canada
- Prior art keywords
- chamber
- waste
- microwave
- unit according
- steam
- Prior art date
- 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.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims abstract description 35
- 230000008569 process Effects 0.000 title claims abstract description 35
- 238000004659 sterilization and disinfection Methods 0.000 title claims abstract description 18
- 239000010781 infectious medical waste Substances 0.000 title claims abstract description 14
- 239000002699 waste material Substances 0.000 claims abstract description 46
- 238000010438 heat treatment Methods 0.000 claims abstract description 8
- 238000012546 transfer Methods 0.000 claims description 12
- 238000007599 discharging Methods 0.000 claims description 11
- 238000002347 injection Methods 0.000 claims description 6
- 239000007924 injection Substances 0.000 claims description 6
- 238000010276 construction Methods 0.000 claims description 2
- 239000002184 metal Substances 0.000 claims 1
- 238000007789 sealing Methods 0.000 claims 1
- 239000000463 material Substances 0.000 description 4
- 244000005700 microbiome Species 0.000 description 4
- 230000006378 damage Effects 0.000 description 3
- 241000700605 Viruses Species 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000002844 continuous effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000002779 inactivation Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 230000004083 survival effect Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09B—DISPOSAL OF SOLID WASTE NOT OTHERWISE PROVIDED FOR
- B09B3/00—Destroying solid waste or transforming solid waste into something useful or harmless
- B09B3/0075—Disposal of medical waste
-
- 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
- A61L11/00—Methods specially adapted for refuse
-
- 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
-
- 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
- A61L2/12—Microwaves
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/64—Heating using microwaves
- H05B6/78—Arrangements for continuous movement of material
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B2206/00—Aspects relating to heating by electric, magnetic, or electromagnetic fields covered by group H05B6/00
- H05B2206/04—Heating using microwaves
- H05B2206/045—Microwave disinfection, sterilization, destruction of waste...
Landscapes
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Epidemiology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Environmental & Geological Engineering (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Apparatus For Disinfection Or Sterilisation (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
The invention relates to a process and a unit for disinfection or sterilisation of infectious waste, the waste being comminuted, moistened and thermally treated by irradiation with microwaves.
For the purpose of reliable and rapid disinfection or sterilisation in a rapid and economical manner, provision is made that the comminuted waste is loaded into a sealable microwave chamber and at the same time is moistened and preheated by exposure to steam.
The waste is heated by at least temporarily simultaneous exposure to steam and irradiation with microwaves and is kept there for a minimum time until the waste is disinfected or sterilised. To speed up the process, heat treatment can be carried out at a heat treatment temperature of over 100 ·C and at least 1,3 bar (absolute).
For the purpose of reliable and rapid disinfection or sterilisation in a rapid and economical manner, provision is made that the comminuted waste is loaded into a sealable microwave chamber and at the same time is moistened and preheated by exposure to steam.
The waste is heated by at least temporarily simultaneous exposure to steam and irradiation with microwaves and is kept there for a minimum time until the waste is disinfected or sterilised. To speed up the process, heat treatment can be carried out at a heat treatment temperature of over 100 ·C and at least 1,3 bar (absolute).
Description
w o 91/16~ 2 ~ ~ 0 3 '1 ~ P~T/~S91/02451 Process and Unit for Disinfection and Sterilisation of infectious Waste The invention relates to a process for disinfection cr sterilisa~ion of infectious waste, in which the waste is granulated, wetted and thermally treated by irradiation with microwaves, and a unit for that purpose.
A unit which, as a compact disposal plant, comprises an input section embodying a waste shredder and a microwave chamber for the he.at treatment is known for such a process for treating infectious waste with the aid of microwaves from German Patent Specification 35 05 570. A conveyor path which is surrounded by a microwave-transmissive housing is provided in the microwave chamber. A multiplicity of microwave generators which irradiate the granulated and wetted infectious waste with microwaves until it is sterilised is arran~ed along the conveyor path. To prevPnt the escapP of mlcrobes and steam, the entire unit is outwardly sealPd.
.
For this process carried out with the known unit, it has been found th2t the destruction of microorganisms and also the inactivation o; viruses necPssary for a disinfection and, in particular, sterilisa-tion require long heat treatment throughput times. The energy consumption for a heat treatment carried out in this way is consequently high.
It is therPfore an object of the invention to provide a process and a unit for disinfection and sterilisation of infectious waste which ma~es possible a reliablP disinfection or sterilisation in a rapid and economical manner.
This object is achieved in accordance with the features of claims 1 and S, respecti vely.
This provides a process and a unit for carrying out the prccess whicr, shorten the heat treatmen~ for the disin;ection or slerilisation substan-.
.. . . . . .
~' ~ ' : - . . .. .
.
, ~ ~ - , .
~33~
w o 91/16084 PCT/~S~1/0 tially as a result of simultaneous use of moist heat, microwaves and eventually overpressure and at the same tlme also prevent the survival of resistant microorganisms and viruses. The feeding-in of steam during the charging operation already ensures a rapid and good preheating with the introduction of moisture. The subsequent heatirg-up and holding phase makes possible an effective attack by microwaves in the moist overpressure medium.
A substantial reduction or destruction of all microorganisms, etc. is thus possible within a few minutes.
Preferably, the temperatures in the micro~/ave chamber are set between lOO
arc; 145C. For the purpose of as uniform as possible feeding-in of the steam, a plurality of injection pcints can be aistributed at a distance along the microwave chamber. A distribution of the microwa~es 2S a result of reflection can be achieved by a metallic conveyor screw. For a continucus waste flow, the microwave chamber can be equipped at the input si~e with a transfer chamber and at the output side with a discharge chamber having conveyor screws which compact the waste at the input ard output side cf the microwave chamber to allow treatment at a pressure of at least 1,3 bar (absolute) in the microwave chamber. To speed up the process, the treatment can be carried out at a pr~ssure of at least 2 bar (absolute).
Other objects, features and advantages of the invention will become more fully apparent upon consideration of the claims and the following descript-ion.
The invention is explained in greater detail below with reference to the exemplary embodiment shown in the attached drawings.
Fig. l shows a longitudinal section cf a unit for disin;ection and sterilisation of in;ectious waste;
Fig. 2 shows a cross section in accordance with Figure 1.
Figures l and 2 show a unit for treating, in particular slerilising, infectious waste, which is integrated in a container l.
For receiving infectious waste, an input section co~prises ar infeed gate which is separated by a revolving wing into a loading compartment 2 and a shredder hopper 3~ These both compartments can be sealed in a fluid-light .
A unit which, as a compact disposal plant, comprises an input section embodying a waste shredder and a microwave chamber for the he.at treatment is known for such a process for treating infectious waste with the aid of microwaves from German Patent Specification 35 05 570. A conveyor path which is surrounded by a microwave-transmissive housing is provided in the microwave chamber. A multiplicity of microwave generators which irradiate the granulated and wetted infectious waste with microwaves until it is sterilised is arran~ed along the conveyor path. To prevPnt the escapP of mlcrobes and steam, the entire unit is outwardly sealPd.
.
For this process carried out with the known unit, it has been found th2t the destruction of microorganisms and also the inactivation o; viruses necPssary for a disinfection and, in particular, sterilisa-tion require long heat treatment throughput times. The energy consumption for a heat treatment carried out in this way is consequently high.
It is therPfore an object of the invention to provide a process and a unit for disinfection and sterilisation of infectious waste which ma~es possible a reliablP disinfection or sterilisation in a rapid and economical manner.
This object is achieved in accordance with the features of claims 1 and S, respecti vely.
This provides a process and a unit for carrying out the prccess whicr, shorten the heat treatmen~ for the disin;ection or slerilisation substan-.
.. . . . . .
~' ~ ' : - . . .. .
.
, ~ ~ - , .
~33~
w o 91/16084 PCT/~S~1/0 tially as a result of simultaneous use of moist heat, microwaves and eventually overpressure and at the same tlme also prevent the survival of resistant microorganisms and viruses. The feeding-in of steam during the charging operation already ensures a rapid and good preheating with the introduction of moisture. The subsequent heatirg-up and holding phase makes possible an effective attack by microwaves in the moist overpressure medium.
A substantial reduction or destruction of all microorganisms, etc. is thus possible within a few minutes.
Preferably, the temperatures in the micro~/ave chamber are set between lOO
arc; 145C. For the purpose of as uniform as possible feeding-in of the steam, a plurality of injection pcints can be aistributed at a distance along the microwave chamber. A distribution of the microwa~es 2S a result of reflection can be achieved by a metallic conveyor screw. For a continucus waste flow, the microwave chamber can be equipped at the input si~e with a transfer chamber and at the output side with a discharge chamber having conveyor screws which compact the waste at the input ard output side cf the microwave chamber to allow treatment at a pressure of at least 1,3 bar (absolute) in the microwave chamber. To speed up the process, the treatment can be carried out at a pr~ssure of at least 2 bar (absolute).
Other objects, features and advantages of the invention will become more fully apparent upon consideration of the claims and the following descript-ion.
The invention is explained in greater detail below with reference to the exemplary embodiment shown in the attached drawings.
Fig. l shows a longitudinal section cf a unit for disin;ection and sterilisation of in;ectious waste;
Fig. 2 shows a cross section in accordance with Figure 1.
Figures l and 2 show a unit for treating, in particular slerilising, infectious waste, which is integrated in a container l.
For receiving infectious waste, an input section co~prises ar infeed gate which is separated by a revolving wing into a loading compartment 2 and a shredder hopper 3~ These both compartments can be sealed in a fluid-light .
2~8~ 9 w ~ 91/1608~ PCT/US~1/02451 manner by means o~ a cover. Arranged in the shredder hopper 3 is a crank 4 which precomminutes the waste and ~eeds it to a waste shredder 5 adjoining the bottom side. The escape of microbes or steam can be prevented by means of a sterile filter 6. Furthermore, at least one injection point 7 is let into the shredder l1opper 3 for feeding-in steam. The hopper walls are preferably thermally insulated, but may also be constructed as indirectly heatable.
The waste shredder 5 comprises a cutting mechanism having two opposed cutter sha~ts 8 and shreds the refuse material fed through the shredder hopper 3 with the aid of the crank 4.
Adjoining the waste shredder 5 is a transfer container 9 which is used as an intermediate store for the comminuted waste. Located at the sides o; the transfer container 9 are filling level monitors 10 for a minimum or maximum filling level. The shredder 5 is timed so that the filling level of the transfer container 9 always varies between minimum and maximum. In addition, a liquid filling-level monitor 11 which emits a warning at excessively high liquid level is installed. From the bottom of the ~ransfer container 9, a transfer screw 12 (Fig. 2) conveys the comminuted waste to a microwave chamber 13. The transport screw 12 comprises a screw beam and is driven by a geared motor whilch is controlled by the filling level monitor 10 and the microwave chamber 13. The comminuted waste is transferred to the microwave chamber 13 by means of the conveyor screw 12.
The microwave chamber 13 comprises a tubular or channel-shaped process chamber 14 which is arranged between the transfer container 9 and a dis-charging chamber 15. The connec~ion of the microwave chamber 13 on the input and output side can be sealed in a fluid-tight manner by means of a slide or a shutt-off valve 16, 17 in each case. Arranged at a distance from each other along the process chamber 14 is a plurality o~ microwave generators 18. The process chamber 14 is of metallic construction or is encased with a material which is not transmissive for microwaves and has individual cutouts or windows for coupling in the microwave beams, which cutouts or windows are sealed with microwave-transmissive material. The microwave generators 18 are connected to the cutouts or windows by means of a wave guide and resonance chamber system in a 1luid-tight and pressure-loadable manner. Preferably, every microwave generator 18 radiates microwaves into the microwave chamber 13 via one or two cutouts which are rotated with respect to one another in : , : .: , : - : ,:: .. -. . . : . . . . . . : . :
.: - . ,. . , . : . :
. . . . -, ~ . ~ . . . .
wo 9"l2o~8 ~ 3 l~ ~ pcT/us9l/o2~sl the circumferential direction. The working frequency of the microwave generators 18 can be appropriately chosen and in this case is 2450 MHz.
Arranged in the process chamber 14 is a conveying device 19, in this case a conveyor screw (process screw), which preferably extends over the entire length of the process chamber 14. This process screw 19 comprises a screw -beam and is composed of a material which reflects the microwaves. It can be driven by a geared motor 20, in particular in a forward-rotating manner for filling the microwave chamber and in a forward-rotating and reverse-rotating manner with the microwave chamber isolatecl (closed shut-off valves 16, 17) during a chargewise operation.
A plurality of nozzles 21 arranged at a distance from each other are let into the wall of the passage housing along the process chamber 14. These nozzles 21 are injection points for feeding in steam and are connected for this purpose to a steam generator 23 via a feed pipe system 22. At leasl one nozzle 21 is located in the input region of the microwave chamber 13 and each nozzle 21 can preferably be connected and switched off by means of its own valve 24. The pressure settable by feeding steam intff the microwave chamber 13 can be regulated and kept constant by means of a pressure-mainte-nance valve 25.
The choice of the dimensions of the microwave chamber 13 is such that charges o^ in~ectious waste of between, preferably, 200 and 400 1 can be received.
The discharging chamber lS connected to the output side of the microwave chamber 13 comprises a tubular passage housing 27 in which a conveyor screw 28 (discharge screw) is arranged and is driven by means of a geared motor.
Housin~ 27 and screw 28 are preferably composed of siainless steel. For a betler mobile operation of the unit, the discharging chamber 15 is connected to the microwave chamber 13 by means of a rotary link 29. Consequently, if not in operation, the discharging chamber 15 can be swung upward by means of a geared motor 30 (Fig~ 1) and if in operation, can be swung out of the container 1 (Fig. 2). The choice of the dimensions o, the discharging chamber 15 is such that a charge previously treated in the microwave chamber 13 can be received completely.
Fcr a heat treatment at at least 1,3 bar (absolute), preferably 2 bar (absolute), the process chamber 14 can be formed as a pressure chamber. The .. . .
- . : , .
.
, 2B8a3'1'~
w ~ ~1/160B~ Pc~/uss shut-off devices 16, 17 are constructed as pressure-loadable. For a contin-uous waste flow the transfer container conveyor screw 12 and the discharging chamber conveyor screw 28 can compact the waste at the input and output side of the microwave chamber 13 to shut-off the latter. For this purpose the conveyor screws 12, 28 can run with a higher or lower speed as the process screw 19. Alternatively, the screws 12, 28 can be provided with screw path di~t~rencPs ! . _ _ .
A process-control computer is provided for the electrical control. It is located in a switch cabinet 31 and contains a program for automatic and manual operation, i.e. for switch and sensor scanning, motor and microwave conlrol, and moni~oring and driving display devices.
The mode o~ operation of the unit described above and the process which can be carried out with it to treat infectious waste is described below.
The infectious waste, which is stored, for example, in a collection con-tainer 33 is filled into the loading compartment 2. An additional lifting and tipping device 32 may be provided for lifting the collection container 33. As a result or actuating the crank 4, the waste is fed to the waste shrP~der 5 while being precomminuted. The granulated waste then falls into the transfer container 9. The f~illing level monitoring system regulates the comminution operation by switching off if the filling level monitor 10 is reached. The amount of granulated waste corresponding to a chosen charge is conveyed out of the transfer container 9 by means of the conveyor screw 12 and is moved into the microwave chamber ~3 by means of the forward-rotating process screw 19. With the beginning of the input of the waste into the microwave chamber 13, the feeding-in of steam is started. The injection of the s~eam results in a moistening and preheating of the waste to about 50 to 100C during a filling operation.
For 2 continuous waste fiow the preheatPd waste is slowly moved through the proc-,, chamber 14 heating the waste by at least temporarily simultaneous exposure to steam and irradiation with microwaves and keeping there for a minimum time.
For a continuous waste flow at a pressure of at least 1,3 bar tabsolute) in the process chamber 14 the conveyor screws 12, 28 compact the waste at the . : ' ' ' - ' .- ~ . ,` ~ . . ' .... . . ............... ... .. .. ~ . - . . . . .
.. . . .. . . . ... . .
2~03~9 ~ ~
The waste shredder 5 comprises a cutting mechanism having two opposed cutter sha~ts 8 and shreds the refuse material fed through the shredder hopper 3 with the aid of the crank 4.
Adjoining the waste shredder 5 is a transfer container 9 which is used as an intermediate store for the comminuted waste. Located at the sides o; the transfer container 9 are filling level monitors 10 for a minimum or maximum filling level. The shredder 5 is timed so that the filling level of the transfer container 9 always varies between minimum and maximum. In addition, a liquid filling-level monitor 11 which emits a warning at excessively high liquid level is installed. From the bottom of the ~ransfer container 9, a transfer screw 12 (Fig. 2) conveys the comminuted waste to a microwave chamber 13. The transport screw 12 comprises a screw beam and is driven by a geared motor whilch is controlled by the filling level monitor 10 and the microwave chamber 13. The comminuted waste is transferred to the microwave chamber 13 by means of the conveyor screw 12.
The microwave chamber 13 comprises a tubular or channel-shaped process chamber 14 which is arranged between the transfer container 9 and a dis-charging chamber 15. The connec~ion of the microwave chamber 13 on the input and output side can be sealed in a fluid-tight manner by means of a slide or a shutt-off valve 16, 17 in each case. Arranged at a distance from each other along the process chamber 14 is a plurality o~ microwave generators 18. The process chamber 14 is of metallic construction or is encased with a material which is not transmissive for microwaves and has individual cutouts or windows for coupling in the microwave beams, which cutouts or windows are sealed with microwave-transmissive material. The microwave generators 18 are connected to the cutouts or windows by means of a wave guide and resonance chamber system in a 1luid-tight and pressure-loadable manner. Preferably, every microwave generator 18 radiates microwaves into the microwave chamber 13 via one or two cutouts which are rotated with respect to one another in : , : .: , : - : ,:: .. -. . . : . . . . . . : . :
.: - . ,. . , . : . :
. . . . -, ~ . ~ . . . .
wo 9"l2o~8 ~ 3 l~ ~ pcT/us9l/o2~sl the circumferential direction. The working frequency of the microwave generators 18 can be appropriately chosen and in this case is 2450 MHz.
Arranged in the process chamber 14 is a conveying device 19, in this case a conveyor screw (process screw), which preferably extends over the entire length of the process chamber 14. This process screw 19 comprises a screw -beam and is composed of a material which reflects the microwaves. It can be driven by a geared motor 20, in particular in a forward-rotating manner for filling the microwave chamber and in a forward-rotating and reverse-rotating manner with the microwave chamber isolatecl (closed shut-off valves 16, 17) during a chargewise operation.
A plurality of nozzles 21 arranged at a distance from each other are let into the wall of the passage housing along the process chamber 14. These nozzles 21 are injection points for feeding in steam and are connected for this purpose to a steam generator 23 via a feed pipe system 22. At leasl one nozzle 21 is located in the input region of the microwave chamber 13 and each nozzle 21 can preferably be connected and switched off by means of its own valve 24. The pressure settable by feeding steam intff the microwave chamber 13 can be regulated and kept constant by means of a pressure-mainte-nance valve 25.
The choice of the dimensions of the microwave chamber 13 is such that charges o^ in~ectious waste of between, preferably, 200 and 400 1 can be received.
The discharging chamber lS connected to the output side of the microwave chamber 13 comprises a tubular passage housing 27 in which a conveyor screw 28 (discharge screw) is arranged and is driven by means of a geared motor.
Housin~ 27 and screw 28 are preferably composed of siainless steel. For a betler mobile operation of the unit, the discharging chamber 15 is connected to the microwave chamber 13 by means of a rotary link 29. Consequently, if not in operation, the discharging chamber 15 can be swung upward by means of a geared motor 30 (Fig~ 1) and if in operation, can be swung out of the container 1 (Fig. 2). The choice of the dimensions o, the discharging chamber 15 is such that a charge previously treated in the microwave chamber 13 can be received completely.
Fcr a heat treatment at at least 1,3 bar (absolute), preferably 2 bar (absolute), the process chamber 14 can be formed as a pressure chamber. The .. . .
- . : , .
.
, 2B8a3'1'~
w ~ ~1/160B~ Pc~/uss shut-off devices 16, 17 are constructed as pressure-loadable. For a contin-uous waste flow the transfer container conveyor screw 12 and the discharging chamber conveyor screw 28 can compact the waste at the input and output side of the microwave chamber 13 to shut-off the latter. For this purpose the conveyor screws 12, 28 can run with a higher or lower speed as the process screw 19. Alternatively, the screws 12, 28 can be provided with screw path di~t~rencPs ! . _ _ .
A process-control computer is provided for the electrical control. It is located in a switch cabinet 31 and contains a program for automatic and manual operation, i.e. for switch and sensor scanning, motor and microwave conlrol, and moni~oring and driving display devices.
The mode o~ operation of the unit described above and the process which can be carried out with it to treat infectious waste is described below.
The infectious waste, which is stored, for example, in a collection con-tainer 33 is filled into the loading compartment 2. An additional lifting and tipping device 32 may be provided for lifting the collection container 33. As a result or actuating the crank 4, the waste is fed to the waste shrP~der 5 while being precomminuted. The granulated waste then falls into the transfer container 9. The f~illing level monitoring system regulates the comminution operation by switching off if the filling level monitor 10 is reached. The amount of granulated waste corresponding to a chosen charge is conveyed out of the transfer container 9 by means of the conveyor screw 12 and is moved into the microwave chamber ~3 by means of the forward-rotating process screw 19. With the beginning of the input of the waste into the microwave chamber 13, the feeding-in of steam is started. The injection of the s~eam results in a moistening and preheating of the waste to about 50 to 100C during a filling operation.
For 2 continuous waste fiow the preheatPd waste is slowly moved through the proc-,, chamber 14 heating the waste by at least temporarily simultaneous exposure to steam and irradiation with microwaves and keeping there for a minimum time.
For a continuous waste flow at a pressure of at least 1,3 bar tabsolute) in the process chamber 14 the conveyor screws 12, 28 compact the waste at the . : ' ' ' - ' .- ~ . ,` ~ . . ' .... . . ............... ... .. .. ~ . - . . . . .
.. . . .. . . . ... . .
2~03~9 ~ ~
4 PCI'/US91/02~51 -`
input and output side of the process chamber 14 while preheating of the waste using steam and microwaves takes place as described above.
For a chargewise waste flow at a pressure of at least 1,3 bar (absolute), preferably 2 bar (absolute), in the process chamber 1~ formed as a pressure chamber the shut-off valve 16 of the microwave chamber 13 on the input side is first opened and the shut-off valve 17 on the output side is prefPrably closed. The infectious waste is filled into the loading compartmen~ 2, comminuted and moved into the pressure chamber. With the beginnung of the input of the waste into the pressure chamber the feeding-in of steam is started. The injection of the stearn results in a moistening and preheating of the waste to about 50 to 100C during a filling operation of about 3 to 10 minutes for charges between 200 and 400 l.
Once the microwave chamber 13 has been filled with comminuted waste, the shut-off valve 16 on the input side and the one on the output side are closed. Consequently, the microwave chamber 13 is isolated from the transfer container 9 and the discharging chamber 15. The further steam iniection with preferably saturated steam results in the build up of a pressure which is kept constant by means of the pressure-maintenance valve 25. The saturated steam from the steam generator 23 has a working pressure of up to 6 bar, i.e. a woirking temperature-of 165C.
Additionally, microwave beams are coupled into the microwave chamber 13.
During the microwave treatment the process screw 19 rotates ~orwards and backwards in order to prevent reflection back-radiation onto the microwave generators 18. Once the chosen pressure of at least 1,3 bar (absolute) has been reached in the microwave chamber 13, the steam exposure is switched off. The desired treatment temperature of over 100C, preferably 130 to 145C, can be regulated by means of a microwave radiation. This temperaturP
is maintained for a certain minimum time in order to ensure the destruction of the microorganisms etc. Then the shut-off valve 17 is opened and the charge of treated waste is emptied into the discharging chamber 15.
The shut-o~f valve 17 of the microwave chamber 13 on the output side isclosed again in order to prevent a fresh contamination of the already treated waste. In the discharging chamber 15 the waste is able to cool further and when the subsequent charge is transferred from the microwave - - .. . . .
.. . .. . .
... . . .
WO 91/161)84 e~ VS91/02451 chamber 13, it is ejected as disinfected or s-terilised waste for removal by transporcation.
Although the invention has been described in connection with what is presently considered to be the most pract;ical and pre~erred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment, but rather is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
.. - . ~ . . . . . .
~ . ; ., , ,,, ......... . . . . ~ . . : . .
input and output side of the process chamber 14 while preheating of the waste using steam and microwaves takes place as described above.
For a chargewise waste flow at a pressure of at least 1,3 bar (absolute), preferably 2 bar (absolute), in the process chamber 1~ formed as a pressure chamber the shut-off valve 16 of the microwave chamber 13 on the input side is first opened and the shut-off valve 17 on the output side is prefPrably closed. The infectious waste is filled into the loading compartmen~ 2, comminuted and moved into the pressure chamber. With the beginnung of the input of the waste into the pressure chamber the feeding-in of steam is started. The injection of the stearn results in a moistening and preheating of the waste to about 50 to 100C during a filling operation of about 3 to 10 minutes for charges between 200 and 400 l.
Once the microwave chamber 13 has been filled with comminuted waste, the shut-off valve 16 on the input side and the one on the output side are closed. Consequently, the microwave chamber 13 is isolated from the transfer container 9 and the discharging chamber 15. The further steam iniection with preferably saturated steam results in the build up of a pressure which is kept constant by means of the pressure-maintenance valve 25. The saturated steam from the steam generator 23 has a working pressure of up to 6 bar, i.e. a woirking temperature-of 165C.
Additionally, microwave beams are coupled into the microwave chamber 13.
During the microwave treatment the process screw 19 rotates ~orwards and backwards in order to prevent reflection back-radiation onto the microwave generators 18. Once the chosen pressure of at least 1,3 bar (absolute) has been reached in the microwave chamber 13, the steam exposure is switched off. The desired treatment temperature of over 100C, preferably 130 to 145C, can be regulated by means of a microwave radiation. This temperaturP
is maintained for a certain minimum time in order to ensure the destruction of the microorganisms etc. Then the shut-off valve 17 is opened and the charge of treated waste is emptied into the discharging chamber 15.
The shut-o~f valve 17 of the microwave chamber 13 on the output side isclosed again in order to prevent a fresh contamination of the already treated waste. In the discharging chamber 15 the waste is able to cool further and when the subsequent charge is transferred from the microwave - - .. . . .
.. . .. . .
... . . .
WO 91/161)84 e~ VS91/02451 chamber 13, it is ejected as disinfected or s-terilised waste for removal by transporcation.
Although the invention has been described in connection with what is presently considered to be the most pract;ical and pre~erred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment, but rather is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
.. - . ~ . . . . . .
~ . ; ., , ,,, ......... . . . . ~ . . : . .
Claims (14)
1. Process for disinfection or sterilisation of infectious waste, comprising the steps of a) comminuting infectious waste, b) filling chargewise or continuously the waste into a sealable microwave chamber, c) moistening and preheating the waste by exposure to steam, and d) then heating the waste by at least temporarily simultaneous exposure to steam and irradiation with microwaves and keeping there for a minimum time.
2. Process according to claim 1, wherein the waste is heated to a heat-treatment temperature of over 100°C at a pressure of at least 1,3 bar (absolute) preferably 2 bar (absolute).
3 Process according to claim 1, wherein said minimum time is 1 to 10 minutes.
4. Process according to claims 1, comprising a further step of moving the waste forward and backward during irradiation with microwaves.
5. Unit for carrying out the process according to claim 1 or 2 with an outwardly sealable construction comprising an input section embodying a shredder and a microwave chamber, adjoining the latter, in the form of a passage chamber comprising a conveyor screw for moving the waste past a plurality of microwave generators arranged on the outside and next to each other in the flow direction, and said microwave chamber is formed from a process chamber having controllable nozzles and also feed pipes, connected to the latter, for admitting steam in the microwave chamber and for the purpose of temperature regulation in conjunction with the microwaves and having shut-off devices arranged on the input and output side for the tem-porary sealing of the microwave chamber.
6. Unit according to claim 5, wherein said process chamber is formed from a pressure chamber.
7. Unit according to claim 5, wherein the conveyor screw in the mi-crowave chamber can be run in a forward-rotating and reverse-rotating man-ner.
8. Unit according to claim 5, wherein said microwave chamber can be operated at temperatures between 100° and 145°C.
9. Unit according to claim 5, wherein said feed pipes for the steam comprise a plurality of injection points distributed at a distance along the microwave chamber.
10. Unit according to claim 5, wherein said microwave chamber is ar-ranged between a transfer container and a discharging chamber in which con-veyor screws can be run to compact the waste at the input side and the output side of the microwave chamber.
11. Unit according to claim 10, wherein said conveyor screws of the transfer container and discharging chamber run with a higher or lower speed than the conveyor screw of the microwave chamber.
12. Unit according to claim 5, wherein said process chamber is desi-gned to receive charge sizes of 200 to 400 1.
13. Unit according to claim 5, wherein said process chamber is con-structed as a tubular metal housing with microwave-transmissive windows or cutouts to which a guide system of the microwave generators is connected.
14. Unit according to claim 13, wherein two windows or cutouts, ar-ranged offset by 180° in the circumferential direction with respect to each other, are provided, respectively.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4012057.0 | 1990-04-13 | ||
| DE4012057A DE4012057C1 (en) | 1990-04-13 | 1990-04-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2080349A1 true CA2080349A1 (en) | 1991-10-14 |
Family
ID=6404404
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002080349A Abandoned CA2080349A1 (en) | 1990-04-13 | 1991-04-10 | Process and unit for disinfection and sterilisation of infectious waste |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0451317A1 (en) |
| AU (1) | AU642486B2 (en) |
| CA (1) | CA2080349A1 (en) |
| DE (1) | DE4012057C1 (en) |
| IT (1) | IT1245043B (en) |
| WO (1) | WO1991016084A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002024354A1 (en) | 2000-09-22 | 2002-03-28 | Environmental Waste International Inc. | Medical waste treatment unit |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4129304A1 (en) * | 1991-09-03 | 1993-03-04 | Fuerst Zu Loewenstein Wertheim | METHOD AND DEVICE FOR DISINFECTING OR STERILIZING INFECTIOUS WASTE, LIKE HOSPITAL |
| US5362443A (en) * | 1991-12-27 | 1994-11-08 | Nippon Metal Industry Co., Ltd. | Method and apparatus for disposal of medical waste |
| FR2757063A1 (en) * | 1996-12-13 | 1998-06-19 | Eskom | METHOD AND DEVICE FOR TREATING MATERIALS, ESPECIALLY STERILIZING INFECTIOUS MEDICAL WASTE |
| UA78172C2 (en) * | 2003-07-28 | 2007-02-15 | Товариство З Обмеженою Відповідальністю "Обнінський Центр Науки І Технологій" | Method and device for sterilising infected materials |
| US8586899B2 (en) * | 2008-11-24 | 2013-11-19 | Jeffrey H. Mackay | Apparatus and method for mass sterilization and pasteurization of food products |
| CN113104429B (en) * | 2021-04-15 | 2022-07-29 | 湖南臻和亦康医疗用品有限公司 | Garbage bin that possesses categorised recovery processing function of abandonment gauze mask |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3753651A (en) * | 1970-08-27 | 1973-08-21 | Wave Energy Systems | Method and apparatus for surface sterilization |
| DE3400189A1 (en) * | 1984-01-02 | 1985-07-11 | KEG Krankenhausentsorgungsgesellschaft mbH, 1000 Berlin | Method of disposing of infectious hospital refuse and devices for carrying the method out |
| DE3505570C1 (en) * | 1985-02-18 | 1991-01-24 | GVB SANIMED Hygiene- und Medizintechnik GmbH, 3070 Nienburg | Device for the treatment of infectious waste by means of microwaves |
| US4861956A (en) * | 1986-10-17 | 1989-08-29 | Magnetronics, Inc. | Microwave/steam sterilizer |
| ES2037112T3 (en) * | 1987-01-14 | 1993-06-16 | Rolf Emil Roland | DISINFECTION PLANT FOR CONTAMINATED HOSPITAL WASTE. |
| DE3710156A1 (en) * | 1987-03-27 | 1988-10-06 | Wolfgang Schinke | Device for treating infectious waste by microwaves |
| US4896010A (en) * | 1987-12-07 | 1990-01-23 | Micro Dry, Incorporated | Microwave drying & sanitizing of fabric |
| DD271454A1 (en) * | 1988-04-20 | 1989-09-06 | Schwerin Bezirkskrankenhaus | DEVICE FOR DISINFECTING AND STERILIZING INFECTED MUELL WITH THE HELP OF MICROWAVES |
| DE8810087U1 (en) * | 1988-08-08 | 1988-11-24 | Roland, Rolf Emil, 6688 Illingen | Heated conveyor for disinfecting contaminated, shredded hospital waste |
-
1990
- 1990-04-13 DE DE4012057A patent/DE4012057C1/de not_active Expired - Fee Related
- 1990-04-27 EP EP90108009A patent/EP0451317A1/en not_active Ceased
-
1991
- 1991-04-09 IT ITTO910252A patent/IT1245043B/en active IP Right Grant
- 1991-04-10 CA CA002080349A patent/CA2080349A1/en not_active Abandoned
- 1991-04-10 WO PCT/US1991/002451 patent/WO1991016084A1/en active Application Filing
- 1991-04-12 AU AU74390/91A patent/AU642486B2/en not_active Ceased
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002024354A1 (en) | 2000-09-22 | 2002-03-28 | Environmental Waste International Inc. | Medical waste treatment unit |
Also Published As
| Publication number | Publication date |
|---|---|
| AU642486B2 (en) | 1993-10-21 |
| ITTO910252A1 (en) | 1991-10-14 |
| WO1991016084A1 (en) | 1991-10-31 |
| EP0451317A1 (en) | 1991-10-16 |
| AU7439091A (en) | 1991-10-17 |
| IT1245043B (en) | 1994-09-13 |
| ITTO910252A0 (en) | 1991-04-09 |
| DE4012057C1 (en) | 1991-04-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |