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Title:
APPARATUS FOR WASTE DISPOSAL
Document Type and Number:
WIPO Patent Application WO/2008/056163
Kind Code:
A3
Abstract:
Apparatus for disposal of waste material by a thermal treatment process includes a container (11) for receiving waste material for treatment, in which the container comprises a heat-resistant canister (11) and an insert thermoplastic closure member (17), the closure member including an access port for waste material deposited in use in the canister, the canister and closure member including co-operating means for maintaining the closure member in the upper region of the canister before the thermal treatment takes place. The canister comprises a tapered cylinder having its base at the narrow end and the insert closure member comprises.resilient elements (30) which, in use, co-operate with the wall of the canister to maintain the closure member in the desired position. The resilient elements may comprise radially outwardly-projecting extensions which, in use, engage in an annular groove formed in the wall of the canister.

Inventors:
GOUGH MARILYN JILL (GB)
Application Number:
PCT/GB2007/004287
Publication Date:
May 22, 2009
Filing Date:
November 09, 2007
Export Citation:
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Assignee:
SAFE ENVIRONMENTAL SOLUTIONS L (GB)
GOUGH MARILYN JILL (GB)
International Classes:
B09B3/00; A61B19/02; A61L11/00; B65D43/02
Foreign References:
US5401444A1995-03-28
US5248486A1993-09-28
FR2767670A11999-03-05
US2860814A1958-11-18
Attorney, Agent or Firm:
WITHERS & ROGERS LLP et al. (2 Hays LaneLondon, SE1 2HW, GB)
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Claims:

Claims

1. Apparatus for disposal of waste material by a thermal treatment process, the apparatus including a container for receiving waste material for treatment, in which the container comprises a heat-resistant canister and an insert thermoplastic closure member, the closure member including an access port for waste material deposited in use in the canister, the canister and closure member including co-operating means for maintaining the closure member in the upper region of the canister before the thermal treatment takes place.

2. Apparatus according to claim 1, in which the canister comprises a tapered cylinder having its base at the narrow end and the insert closure member comprises resilient elements which, in use, are constrained by the wall of the canister to provide the co-operating means for maintaining the closure member in the desired position before the thermal treatment process.

3. Apparatus according to claim 2, in which the resilient elements comprise radially outwardly-projecting extensions which, in use, engage in an annular, outwardly-directed, groove formed in the wall of the canister.

4. Apparatus according to claim 3, in which the extensions are formed as parts of segments of an annular flange extending from the periphery of the closure member.

5. Apparatus according to claim 4, in which the extensions of the flange segments are formed at the peripheral lower end regions thereof.

6. Apparatus according to any preceding claim, in which the closure member includes an O-ring seal between the periphery thereof and the inner wall of the canister.

7. Apparatus according to any preceding claim, in which the access port includes non-retrieval or non-return means.

8. Apparatus according to claim 7, in which the non-return means comprise an array of radially inwardly-disposed resilient fingers.

9. Apparatus according to any preceding claim, the apparatus including a removable cover member over the access port.

10. Apparatus according to any preceding claim, the apparatus including a lid member for sealing engagement in the upper or open end of the canister following thermal treatment in use.

11. Apparatus according to any preceding claim, the apparatus further comprising a heating chamber in which, in use, the container is placed; a condensing coil provided around the heating chamber for condensing any liquids present in the container, the condensing coil preferably being attached to a filter means, and a condenser pot for collecting any condensate.

12. Apparatus according to claim 11, further including an outermost lid operatively connected with container detection means to prevent operation of the heater in the heating chamber without a container being present therein.

13. Apparatus according to claim 12, in which the outermost lid includes a latch means and latch detection system, whereby the thermal treatment process will not be activated unless the latch means is detected .as operatively engaged.

14. Apparatus according to any of claims 11 to 13, including a printed circuit board and microprocessor for control of the thermal treatment process, in which the printed circuit board is provided in two parts, utilising a first voltage for control purposes and a second voltage for power purposes.

15. A container comprising a heat-resistant canister and an insert thermoplastic closure member including an access port for waste material deposited in use in the canister, the canister and closure member including co-operating means for maintaining the closure member in the upper region of the canister before the thermal treatment takes place, suitable for use in apparatus according to any of claims 1 to 14.

16. A thermoplastic closure member for a canister for use in apparatus according to claim 1, in which the closure member comprises an access port for the passage therethrough of waste material and means for co-operating in use with the canister for maintaining the closure member in the upper region of the canister.

17. A closure member according to claim 16, in which the co-operating means comprise resilient elements.

18. A closure member according to claim 17, the member comprising an annular upper wall and an outer dependent annular flange or skirt formed as spaced-apart segments.

19. A closure member according to claim 18, in which each segment is formed as its outer or distal end region with a radially outwardly-directed lip.

20. A closure member according to any of claims 16 to 19, in which the access port comprises an aperture defined by a rim and including a array of radially inwardly-proj ecting resilient fingers .

21. A method of disposal of waste material, the method comprising placing waste material in a canister having an insert thermoplastic closure member and subjecting the canister and contents to a thermal treatment process in which the closure member loses dimensional integrity and sinks under gravity to form a softened or molten layer over the waste material, and allowing the canister to cool to provide a sealed mass of treated waste material in the lower part of the canister.

22. A canister including a closure member and an outermost lid, substantially as herein described with reference to and as illustrated in the accompanying drawings.

Description:

Apparatus for Waste Disposal

This invention relates to apparatus for the disposal of waste material, in particular for the treatment of infectious and medical waste to render it safe and sterile for disposal purposes. More particularly, the invention provides desk-top apparatus for treatment of such material.

Medical waste material may comprise hardware such as needles, scalpels, syringes, containers for pharmaceutical formulations or body fluids and the like, or soft items such as bandages, cotton wool, items of disposable clothing and the like, all of which may be contaminated from contact with human or animal body fluids, pharmaceutical compositions or other chemicals. The disposal of such materials in a safe and environmentally acceptable manner is a considerable problem; US patent number 5972291 proposes disposal apparatus and a method in with the waste material is heated in a container connected to a filter for biological materials, the heating temperature rendering the materials sterile and, in the case of hardware, either unrecognisable or unreusable, whereafter the treated material may be disposed of as ordinary household waste. As part of the process described in US 5972291, ambient air is directed from outside the apparatus into the heating chamber during the heating step and discharge gases from the container are mixed with the ambient air. In use, the container of medical waste is placed in the heating chamber and sealed with a closure device before the heating stage, the closure device having a vent hole formed therein to allow for escape of gases during the heating stage.

In one aspect, the present invention provides apparatus for disposal of waste material by a thermal treatment process, the apparatus including a container for receiving waste material for treatment, in which the container comprises a heat-resistant canister and an insert thermoplastic closure member, ' the closure member including an access port for waste material deposited in use in the canister, the canister and closure member including co-operating means for maintaining the closure member in the upper region of the canister before the thermal treatment takes place.

In apparatus according to the invention, the co-operating means between the canister and the closure member act to maintain the closure member in the upper or open end region of

the canister, thus maintaining substantially the entire internal volume of the canister for receiving waste material for treatment, until it is determined that thermal treatment should take place. Under the conditions of thermal treatment, the thermoplastic closure member melts or softens or otherwise loses its dimensional integrity, thereby rendering ineffective the co-operating effect and allowing the closure member to sink under gravity within the canister to form a softened or molten layer over the contents thereof and which, on subsequent cooling and in combination with the lower part of the canister containing the treated waste material, provides a sealed mass of treated material in which any sharp edges or points, for example of scalpel blades, syringes, tubes or needles, are at least partially encapsulated or otherwise shielded. The canister may then be removed from the apparatus for mechanical crushing and disposal.

Preferably, the canister comprises a tapered cylinder having its base at the narrow end and the insert closure member comprises resilient elements which, in use, are constrained by the wall of the canister to provide the co-operating means for maintaining the closure member in the desired position before the thermal treatment process. More preferably, the resilient elements comprise radially outwardly-projecting extensions which, in use, engage in an annular, outwardly-directed, groove formed in the wall of the canister. The extensions may be formed as parts of segments of an annular flange extending preferably in a downwards direction from the periphery of the closure member. Desirably, the extensions of the flange segments are formed at the peripheral, preferably lower, end regions thereof. In use, the extensions engage in the groove and resist downward or closure movement of the closure member within the canister in advance of the thermal treatment process.

hi a preferred arrangement, the closure member includes an O-ring seal between the periphery thereof and the inner wall of the canister.

The access port formed in the closure member preferably comprises a central aperture for insertion of waste material to be treated, sized to prevent users inserting their hands in the canister, and also preferably includes non-retrieval or non-return means to prevent or inhibit manual retrieval of material, once deposited in the canister. The non-return means

may, for example, comprise an array of radially inwardly-disposed resilient fingers the tips of which define a preferably circular aperture through which small items may merely be allowed to fall under gravity but which are resiliently displaceable to allow larger items to be pushed through while acting to inhibit withdrawal of the hand, thus discouraging any attempt to insert the hand to withdraw an item, once deposited in the canister.

Preferably, the access port is provided with a removable cover member, the cover member optionally being hingeably connected to a part of the closure member adjacent the access port.

The canister preferably also includes a lid member for sealing engagement in the upper or open end thereof following thermal treatment.

In another aspect, the invention provides a container comprising a heat-resistant canister and an insert thermoplastic closure member as hereinbefore described, suitable for use in apparatus for disposal of waste by a thermal treatment process.

The apparatus for disposal of waste by a thermal treatment process may also comprise a heating chamber in which, in use, the container is placed; a condensing coil provided around the heating chamber and having the purpose of condensing any liquids present in the container, the condensing coil preferably being attached to a filter means, preferably comprising activated carbon, and a condenser pot for collecting any condensate; and an outermost lid operatively connected with container detection means to prevent operation of the heater in the heating chamber unless a container is present therein. The outermost lid preferably also includes a latch means and latch detection system, whereby the thermal treatment process will not operate unless the latch means has been operatively engaged. Heating control may be exercised via a thermocouple secured to the outer surface of the heating chamber which, preferably, is formed from spun aluminium and is tapered according to the configuration of the heat-resistant canister, which also is preferably formed from aluminium or an aluminium-containing alloy. Preferably, the heating chamber includes an insulation layer comprising for example cast foam glass incorporating an air path to provide more uniform heating and a defined air path for cooling purposes.

The insulation is preferably surrounded by a polished stainless steel outer housing which acts as a reflector to assist in the heating and cooling processes. The heater itself is preferably an induction heater.

In operation, the thermal treatment cycle preferably utilises a peak sterilising temperature of not less than 160 0 C, the total cycle time including heating and cooling being typically around 120-130 minutes, of which the sterilising time is typically around 60 minutes. The sterilising temperature also can be altered between 30 and 25O 0 C . To ensure complete bacterial destruction, it is preferred to use a sterilising temperature of 185 0 C for a time of 65 minutes.

Control of the thermal treatment cycle is exercised through a printed circuit board and microprocessor which initially interrogates the apparatus to determine whether a canister is present and, if so, whether the outermost lid is latched in position. The cycle may then be manually started, the thermal treatment cycle including a heating stage, a sterilising stage and a cooling stage. The temperature will be displayed on a display panel and, preferably, a printer automatically produces printed labels on completion of the cycle, one label to be affixed to the canister and the other to be placed in a record book as evidence of the sterilising operation. The latch means for the outermost lid is then automatically unlocked and the outermost lid may be opened and the canister removed for crushing and disposal after sealing with the canister lid member.

Preferably, the printed circuit board is provided in two parts, utilising respectively 24v for control purposes and 24Ov for power purposes. The 24Ov printed circuit board supplies power to the heater band and also supplies 24v power to the control circuitry. The 24v circuitry includes fans respectively for providing cooling to the power supply unit; air flow to the heater chamber and airflow to the filter and main body chamber. The outermost lid and latch detection systems are also incorporated within the 24v control circuitry. The circuitry preferably includes an interface to a computer for tracking and record purposes.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings of which:

Figure 1 is a side elevation of a heating canister including closure member and outermost lid;

Figure 2 is a side elevation of the closure member externally of the canister; and

Figure 3 is a plan view of the closure member as shown in Figure 2.

With reference firstly to Figure 1, the apparatus consists essentially of a tapered or frusto conical canister 11 having a base 12 and a carrying handle 13 pivotably engaged in bosses 14. The wall of the canister has a flared open or upper end 15 and an externally-projecting annular groove 16 below which the wall tapers slightly inwardly to the base. 12. A polyethylene closure member 17, described in more detail with reference to Figures 2 and 3 and shown in cross-section along the line I-I of Figure 3, is fitted in the upper part of the canister to engage with the groove 16. An O-ring 18 provides a seal between the shoulder of the closure member and the inner wall surface of the canister 11. The canister is closed with a metal lid 19 which is an interference fit in the flared, upper part 15 of the canister.

With reference to Figures 2 and 3, the closure member 17 has a flat, annular upper surface 20 with an outer dependent flange or skirt formed as segments 21 separated by vertically-disposed slots 22. The segments 21 are angled slightly outwardly from the shoulder 23 of the upper surface and which, together with the upper part 24 of the flange above the segments 21, defines a groove 25 for receipt of O-ring 18. The lower edges of the flange segments 21 are formed as outwardly-directed lips 26 which, as will be described below in more detail, engage in annular groove 16 formed in the wall of the canister 11.

A central well 27 is formed in the closure member 17, bounded by an upstanding annular rim 28 and having an annular side wall 29. The base of the well is constituted by an array of radially inwardly-projecting fingers 30, the tips of which define a central aperture 31.

As shown in Figure 1 in dashed outline, the closure member 17 is formed with a lid 32 which is hingeably attached to post 33 by radial extension arm 34; the hinging action is provided by reduced-thickness zone 35 of arm 34- which enables the lid to be manually opened and closed by virtue of flexion of the material of the arm. The lid has a flat circular upper face and a depending annular flange 36 which, with the lid in the closed position, engages with rim 28, as shown by the chain-dotted line.

In the closure member as described, the flange segments 17 and the fingers 30 are resiliently deformable, whereby the flange segments are radially inwardly deflected on insertion of the closure member through the flared upper end 15 of the canister 11, until the lips 26 become engaged in annular groove 16. The canister is then ready to receive contaminated waste material, for which purpose the lid 32 is raised and the items concerned are inserted through the well 27, either by being dropped through aperture 31 or, if larger, by being pushed through with displacement of the fingers 30, as shown in dashed outline in Figure 1. The fingers 30 provide an effective guard against manual retrieval of items previously inserted in the canister while still allowing access for materials to be disposed of.

Once the canister is full and ready for thermal treatment, the lid 19 is fitted in place and the contents of the canister are then sealed therein for transporting to the thermal treatment apparatus. The closure member 17 has meanwhile softened or melted in the thermal treatment process to form, on cooling, a protective layer over the treated contents of the canister. Following treatment, the canister is removed from the apparatus, mechanically crushed and can then be safely disposed of.