GB2252316A

GB2252316A - Waste disposal

Info

Publication number: GB2252316A
Application number: GB9200159A
Authority: GB
Inventors: Roger N Ferguson
Original assignee: MEDICAL WASTE INTERNATIONAL LI
Current assignee: MEDICAL WASTE INTERNATIONAL LI
Priority date: 1991-01-04
Filing date: 1992-01-06
Publication date: 1992-08-05
Also published as: GB9200159D0

Abstract

A system for the disposal of medical waste comprises providing a plurality of rigid plastics containers having lockable lids 8 and foot pedals 12. The containers are filled in site and then the lids locked for transport. The containers are transferred to a waste disposal plant where they are emptied and cleansed before being returned to the site. The containers carry a bar code 18 to identify at least the user of the container so that the amount of waste processed for that user can be recorded. To lock the lids, a hook 26 is spring loaded or rotated manually to grip a loop 28 on the lid. The hook is released by inserting a key into the tunnel 30 to engage and rotate the hook. <IMAGE>

Description

WASTE DISPOSAL This invention relates to the disposal of waste, and in particular medical waste produced in hospitals.

A commonly used system for the disposal of waste in hospital wards and operating theatres is to load the waste into colour coded plastics bags. With transmissible diseases a double bagging system may be used. A number of drawbacks is experienced with this system: for example, the bags are punctured and split by sharp objects, they are difficult to seal and often left open, they are not suitable for liquid waste. The system requires additional 'sharps' bins which are of rigid plastics material and are used for the disposal of needles, scalpels and other sharp objects.

The bagged and binned waste is then carried by the hospital porters to a waste collection site, where it may be loaded into a skip. The skip (or the loose bags) is then collected and taken to an incinerator where it is loaded by hand. Thus at several points in the waste disposal cycle there is a danger of bags being damaged when being handled and a consequent danger to the operatives.

Additionally, the cost of the waste disposal procedure has to be accounted for by many hospitals, which leads to particular difficulty when a single company provides collection and disposal facilities for several hospitals.

Some wastes, such as from pathology and radio-chemical areas, require extra-special handling.

There is a need for a medical waste disposal system which reduces the risk to personnel handling the waste, reduces the risk of waste being spilt and facilitates financial accounting for the waste disposal procedure.

In accordance with a first aspect of the invention, there is provide apparatus for the disposal of hospital waste, comprising a plurality of rigid containers for the collection of waste at various locations in the hospital, the containers being readily sealed and readily movable within the confines of the hospital, a vehicle for transporting the containers from the hospital to a waste disposal plant, and a waste disposal plant having means for automatically emptying and cleaning the containers.

The containers may be coded, eg. by colour, to indicate the type of waste which should be placed in the container.

Preferably each container carries a marking to identify the container. Preferably the marking is machine readable and preferably a unique code is given to each container. In this way the type of waste which is expected to be in the container can be identified and the origin of the container can be logged. The marking may indicate, for example, the hospital and' the ward in that hospital.

Preferably means is provided for sterilising the emptied containers, which may then be wrapped so that the container can be returned to a clean environment such as in an operating theatre for re-use.

Preferably the container has a lid which can be closed to form a liquid and gas tight seal. A locking mechanism may provide for the lid to be locked easily, for example by hand pressure, but require a special key for unlocking so that once sealed the container can not be opened easily by unauthorised persons.

The invention also provides a container for the collection of hospital waste, the container being of rigid material, such as plastics, and having a pedal operated lid which is arranged to form a substantially gas and liquid tight seal when closed on the container, and means for locking the lid in the closed position.

Preferably, the container has wheels and a handle so that the container can be wheeled into place and otherwise readily moved.

A further aspect of the invention provides a medical waste disposal plant having means for logging the arrival of a container containing medical waste, means for detecting the presence of radioactive material in the container, means for emptying the container, and means for cleaning the container. Preferably the container also includes means for sterilising and wrapping a container to keep it in sterile condition prior to re-use.

Other aspects, preferred features and advantages of the invention will be apparent from the following description and the accompanying claims.

The invention will be further described by way of example with reference to the accompanying drawings, in which: Figures la to if illustrate a container in accordance with the invention, figures la to id being rear, side, front and plan views, figures le and if showing a detail of a locking mechanism; Figure 2 is a flow chart for a method of medical waste disposal in accordance with the invention; Figure 3 is a schematic view of a first embodiment of a waste disposal plant in accordance with the invention;; Figures 4a to 4d are schematic views of a second embodiment of a waste disposal plant in accordance with the invention, Figure 4a being a plan view, and Figures 4b to 4d being cross-sectional views on lines AA, BB and CC respectively, and Figures 5 and 5a are schematic side and end views, partly cut away, of a third embodiment of the invention, similar to the embodiment of Figure 3.

Figure la to if illustrate a container forming an embodiment of one aspect of the invention. The container 2 has a body part 4 which is integrally moulded of heavy duty plastics material. The body 4 is moulded with rounded internal corners to facilitate cleaning and is closed at its upper end 6 by a lid 8.

The lid 8 and the mating edge of the container carry a gasket (not shown) to form a substantially gas and liquid tight seal when the lid is closed.

The lid 8 is pivoted on the rear wall 10 of the container and is opened by pressing on a foot pedal 12 at the front of the container, near the base.A side wall 14 of the container carries a name plate 16 to identify the hospital which uses the container, and a bar code 18 to identify the particular container.The container stands on a pair of wheels 20 and a rear foot 22 and is moved by tilting forwards onto the wheels 20, hand grips 24 being provided at the upper end 6.

To provide a secure lock for the lid, a spring loaded hook 26 grips a loop 28 on the lid 8 as the lid 8 is pushed down hard, and is released by inserting a long allen key into a tunnel 30 to engage an and rotate the hook 26. In another embodiment the hook 26 need not be spring loaded to the closed position, the hook 26 being rotated manually to lock the lid 8 closed.

Figure 2 is a flow chart illustrating a method of medical waste disposal in accordance with the invention. Referring to the drawing, a set of the containers 2 of figure 1 is delivered to'a hospital.

The containers are sterilised and shrink-wrapped. The delivery of the container can be logged, identifying the container by the bar code 18. A hospital porter moves the container to the point of use, on a trolley.

The containers are unloaded and then unwrapped and the lid unlocked, or this may be done by medical staff in a clean room environment, etc. The container is filled with waste. A container may be coded, eg. by colour, to indicate the appropriate waste for that container. When filled, or finished with, the container lid is locked shut and container then wheeled, or moved on a trolley, to a collection point. The filled containers are stored at the collection point in a modular cage system which is locked to prevent unauthorised access.

The filled containers are then collected at intervals by a refrigerated truck. Preferably the truck utilises a detachable trailer which allows loading of the filled containers by powered roller conveyors,and will carry clean, sterile containers to replace the filled containers as they are removed. The transfer can be automated to provide 1: 1 replacement.

The truck, which can collect containers from other hospitals, then drives to the waste disposal plant which may be located some distance away. The refrigerated trailer prevents or slows degradation of the waste and provides convenient storage for the waste when it is not to be processed immediately.

At the disposal plant (figs. 3 to 5) the containers are downloaded to be emptied, washed, sterilised, dried and wrapped for re-use. On entering the disposal plant the container bar code is read and the container weighed.

All this can be held on a database for monitoring the treatment of the waste and accounting to the hospital etc. Also, on entry the container lid is opened and the contents are scanned for radioactive waste. Any containers with radioactive contents are removed from the line for further investigation.

Preferred forms of waste disposal plant will now be described with reference to figs 3, 4 and 5. The purpose of the plant is to provide in a small area a facility for automatically emptying and cleaning the containers.

The waste is preferably incinerated at the plant site, but if necessary, compacted waste may be fed to a bulk container for transfer to an incinerator.

Figure 3 shows a first embodiment of an inline waste treatment plant 40. Filled containers 2 are delivered from a refrigerated trailer vehicle (41) on a powered roller conveyor 42. Before entry into the fully enclosed treatment station 44, the container lids 8 are unlocked, the contents scanned for radiation, the bar code read and the container weighed. The container is then gripped at its sides and upended over a hopper feed 46 to an incinerator (not shown) as it is taken into the enclosure 44. The container 2 is upended over a retractable compressed air head 48 and suspended on a walking beam 50. The air head blows substantially all of the waste from inside the bin, the waste falling into a hopper for passage to an incinerator. Where the incinerator is remote from the plant 40, the waste may be compacted for transport to the incinerator.

The container is then indexed through a high pressure hot water pre-clean stage 52, where it is washed inside and out, a high pressure steam cleaning stage 54, a liquid or radiation (e.g. ultraviolet) sterilisation stage 56 and a compressed air blow-off stage 58 for drying. The container 2 is then turned right way up, the lid locked and passed on a powered roller conveyor 57 to a shrink-wrap station (not shown).

The waste water from the cleaning process is filtered by a filter 59, treated and discharged to a foul water main. The station 44 operates under slightly negative pressure, the extracted air being filtered to the atmosphere.

Figures 4a to 4d show a plant similar to figure 3 but based on a rotary indexing system.

A central rotating column 60 carries six bin handling arms, 62 a-f . Each arm 62 has a pair of forks 64 on a cranked arm 65 for gripping a container, a raise/lower drive 66 for raising and lowering the arms (and hence the container 2), and a rotating drive 67 for upending the container.

A bin is raised for passage between stations and lowered down over a sprayer, compressed air blower, etc for cleansing. This system allows the container to be held sideways, when it can be lowered into a dip cleansing bath.

Figure 4c shows the intake station 70, where the bar code is read by a reader 71 and the container weighed by a weighing machine 73, unlocked and monitored for radiation by a probe 75. It is then gripped by the forks 64. Diametrically opposite is a dip cleansing tank 72, and a container is shown being lowered into the tank.

Figure 4d shows at 74 a container 2 inverted over a hopper, for transferring bulk waste to a furnace after the intake station 70, and diametrically opposite at 76 a container is shown lowered over and between compressed air pipes 77 for drying after the dip cleansing stage 72.

Figure 4b shows a container 2 at an exit station 78 just prior to inversion, and a steam cleansing station 80 having steam pipes 81.

The rotary unit is enclosed by an extractor hood 82,* expelled air being filtered through an extractor 84.

Stations may be separated by a silhouette, i. e. a panel having an aperture matched to the shape of the bin, or by closable doors or a curtain to reduce cross-contamination, for example to prevent steam from the steam cleaning unit passing through to the sterilisation unit. Means may be provided to hold the container lid 8 in the open position during emptying and cleansing, for example by bearing on the foot pedal 12.

Figures Sa and 5b show a third embodiment of a waste disposal plant, which is similar to the embodiment of Figure 3.

The plant 90 is modular, with a start booth module 92, an end booth module 94 and intermediate booth modules 96. The modules are supported on a support structure 98, and one or more of the modules has a clear panel, e. g. of polymethylmethacrylate, for inspection of the process.

The intermediate booths 96 and end booth 94 each have spray rails 102 for the delivery of liquid or air, and a collection trough 104 for waste from the booth.

The booths have an overhead spray rail 105 and lower spray rails 106 for cleaning the booths in between process runs.

In use, a bin 2 whch has been identified by reading its bar code and then weighed, is inverted and placed on a support rail 108, which runs through the modules 92, 96, 94, in the start booth 92. The lid 8 of the bin is released to drop the waste material into a hopper 110 at the base of the start booth 92. The hopper 110 feeds the waste to a compaction unit (not shown).

A spray head 112 blows compressed air into the inverted bin 2 to dislodge waste from the bin. The bin is then indexed along by a walking beam indexer 114, actuated by a compressed air system 115, into the adjacent booth 96a. A spray head 116 and the associated spray rail 102 wash the bin with high pressure hot water, the waste being collected by trough 104. The bin is then indexed through to the next booth 96b for spraying with high pressure steam by spray rail 102 and spray head 118.

The bin is next indexed through a silhouette 120 into booth 96c, where it is sprayed with liquid sterilising solution and subsequently through a silhouette 122 into end booth 94 where it is blown with compressed air to remove excess liquid and dry the bin. The bin 2 may then be shrink wrapped for further handling.

The booths are illuminated internally by vapour proof light boxes 118 and ventilated by a central ventillation stack 124. Waste from booths 94, 96b and 96c is fed to the trough of booth 96a where it is filtered before discharge to a foul water main.

Various modifications may be made to the described embodiments and it is desired to include all such modifications as fall within the scope of the invention described herein.

Claims

1. Apparatus for the disposal of medical waste comprising a plurality of rigid containers for the collection of waste at various locations in the hospital, the containers being readily sealed and readily movable within the confines of the hospital, a vehicle for transporting the containers from the hospital to a waste disposal plant, and a waste disposal plant including means for automatically emptying and cleaning the containers.

2. Apparatus as claimed in claim 1, wherein the waste disposal plant includes means for sterilising the containers.

3. A container for the collection of medical waste, the container being of rigid material and having a pedal operated lid which is arranged to form a substantially gas and liquid tight seal when closed on the container, and means for locking the lid in the closed position.

4. A container as claimed in claim 3, wherein the container includes a code for identifying the user of the container.

5. A medical waste disposal plant having means for logging the arrival of a container containing medical waste, means for emptying the container, and means for cleaning the container.

6. A plant as claimed in claim 5, including means for sterilising and wrapping the container.

7. A method for the disposal of medical waste from a site, the method comprising supplying a plurality of rigid, closable containers for waste to be deposited in on site, collecting the containers at intervals and transferring them to a waste disposal plant, emptying and cleaning the containers, and returning the containers to the site.

8. Apparatus for the disposal of medical waste, substantially as hereinbefore described with reference to figures 1 and 2, and figure 3, 4 or 5 of the accompanying drawings.

9. A container for the collection of medical waste, substantially as hereinbefore described with reference to figure 1 of the accompanying drawings.

10. A plant for emptying and cleaning medical waste containers, substantially as hereinbefore described with reference to figure 3, 4 or 5 the accompanying drawings.

11. A method for the disposal of medical waste, substantially as hereinbefore described with reference to the accompanying drawings.