A METHOD OF AT LEAST PARTIALLY BREAKING DOWN A MATERIAL OR PRODUCT ITEM OR A COMBINATION OF MATERIALS OR PRODUCT ITEMS

Abstract

A method of at least partially breaking down a material or product item or combination of material or product items. The method includes the steps of introducing said material or product item or combination of material or product items into a treatment vessel, introducing at least one working fluid into the treatment vessel, repeatedly increasing pressure on the material or product item or combination of material or product items in said treatment vessel to above atmospheric pressure and then subsequently depressurising the material or product item or combination of material or product items in the treatment vessel to achieve a pressure reduction in the vessel to effect at least partial breakdown of said material or product item or combination of material or product items.

Claims

1. A method of at least partially breaking down a material or product item or combination of material or product items, the method comprising the steps of: a. introducing said material or product item or combination of material or product items into a treatment vessel or temporarily creating a treatment vessel from the material's or product item's or a combination of materials' or product items' existing casing(s) or carrier(s); b. introducing at least one working fluid into the treatment vessel; c. increasing pressure on the material or product item or combination of material or product items in said treatment vessel to above atmospheric pressure; d. subsequently depressurising the material or product item or combination of material or product items in treatment vessel to achieve a pressure reduction on the material or product item or combination of material or product items in the treatment vessel in the vessel, and e. repeating steps (c) and (d) at least once to effect at least partial breakdown of said material or product item or combination of material or product items.

2. A method as claimed in claim 1 wherein the steps of increasing pressure and subsequently depressurising comprises one treatment cycle and the method includes a plurality of treatment cycles.

3. A method as claimed in claim 1 or claim 2 implemented on a batch basis.

4. A method as claimed in claim 1 or claim 2 implemented on a continuous basis.

5. A method as claimed in claim 4 wherein the material or product item or combination of material or product items has a minimum residence time in the treatment vessel to effect at least partial breakdown.

6. A method as claimed in any one of the preceding claims further comprising one or more size reduction steps before introducing the material or product item or combination of material or product items into the treatment vessel.

7. A method as claimed in any one of the preceding claims wherein introducing the material or product item or combination of material or product items is achieved by conveying the material or product item or combination of material or product items into the treatment vessel either mechanically or using a fluid.

8. A method as claimed in any one of the preceding claims wherein the material or product item or combination of material or product items are introduced into the treatment vessel contemporaneously with the at least one working fluid.

9. A method as claimed in any one of the preceding claims wherein the treatment vessel is sealed during treatment, and the material or product item or combination of material or product items to be treated are introduced before sealing the treatment vessel and any products formed are removed from the treatment vessel after the treatment vessel is unsealed.

10. A method as claimed in any one of the preceding claims further comprising the step of locating the material or product item or combination of material or product items within the treatment vessel to be accessible on one or more sides during treatment.

11. A method as claimed in any one of the preceding claims further comprising the step of optimising the volume of the treatment vessel prior to during or after the introduction of the material or product item or combination of material or product items and controlling/managing a volume during treatment.

12. A method as claimed in any one of the preceding claims further comprising the step of optimising an amount of working fluid introduced to suit the material or product item or combination of material or product items introduced.

13. A method as claimed in any one of the preceding claims further comprising the step of allowing a portion of the at least one working fluid to bypass, purge or exit the treatment vessel without being subject to the full process cycle or undergoing full pressurisation and/or depressurisation through at least one bypass, purge or exit arrangement connected to an outlet of the treatment vessel, apparatus or process arrangement.

14. A method as claimed in any one of the preceding claims wherein the at least one working fluid is injected into the treatment vessel, using at least one injector.

15. A method as claimed in any one of the preceding claims further including the step of treating any exit stream from the treatment vessel to recover the at least one working fluid and/or any other useful material.

16. A method as claimed in any one of the preceding claims wherein the step of increasing the pressure in the treatment vessel is adiabatic pressurisation.

17. A method as claimed in any one of the preceding claims wherein the step of depressurising the treatment vessel is adiabatic expansion.

18. A method as claimed in any one of the preceding claims wherein the step of increasing the pressure in the treatment vessel is of adjustable duration.

19. A method as claimed in any one of the preceding claims wherein the step of depressurisation of the treatment vessel is of adjustable duration.

20. A method as claimed in any one of the preceding claims wherein the step of increasing the pressure in the treatment vessel is adjustable in degree of pressure increase.

21. A method as claimed in any one of the preceding claims wherein the step of depressurisation of the treatment vessel is adjustable in degree of pressure decrease.

22. A method as claimed in any one of the preceding claims wherein the step of increasing the pressure in the treatment vessel is longer in duration than the depressurisation step.

23. A method as claimed in any one of the preceding claims wherein the step of increasing the pressure in the treatment vessel and subsequent depressurisation step occurs a plurality of times with a single charge of at least one working fluid.

24. A method as claimed in any one of the preceding claims further including the step of agitating an environment within the treatment vessel in order to circulate the at least one working fluid within the treatment vessel.

25. A method as claimed in claim 24 wherein agitating the environment within the treatment vessel fluidises the material or product item or combination of material or product items with the at least one working fluid.

26. A method as claimed in any one of the preceding claims wherein the step of increasing the pressure in the treatment vessel is followed by a step of holding the treatment vessel at an elevated pressure before the subsequent depressurisation of the treatment vessel.

27. A method as claimed in any one of the preceding claims further including a step of monitoring the at least partial breakdown of the material or product item or combination of material or product items or treatment vessel for treatment effectiveness.

28. A method as claimed in claims 27 wherein the steps of increasing the pressure in the treatment vessel and subsequent depressurisation of the treatment vessel are varied in real time depending upon the treatment effectiveness.

29. A method as claimed in any one of the preceding claims wherein the at least one working fluid is gaseous.

30. A method as claimed in any one of the preceding claims wherein the at least one working fluid comprises a mixture of phases.

31. A method as claimed in any one of the preceding claims wherein the at least one working fluid comprises a mixture of materials.

32. A method as claimed in any one of the preceding claims wherein the at least one working fluid comprises at least one active component and at least one carrier.

33. A method as claimed in claim 32 wherein the at least one active component comprises one or more reactant and/or one or more solvent.

34. A method as claimed in claim 32 or claim 33 wherein the at least one active component comprises one or more volatile substances.

35. A method as claimed in any one of the preceding claims further including contacting the material or product item or combination of material or product items with at least one catalyst material.

36. A method as claimed in any one of the preceding claims wherein the increase in pressure is applied to the material or product item or combination of material or product items in the treatment vessel.

37. A method as claimed in any one of the preceding claims wherein the increase in pressure is applied within the treatment vessel.

38. A method as claimed in any one of the preceding claims wherein the increase in pressure is applied through the application of at least two pulses of increased pressure and the depressurising occurs through the absence of increased pressure applied by the at least two pulses of increased pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0158] In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

[0159] FIG. 1 is a schematic view of a method of at least partially breaking down a material or product item or combination of material or product items.

[0160] According to a particularly preferred embodiment of the present invention, a method of at least partially breaking down a material or product item or combination of material or product items is provided.

[0161] The particularly preferred embodiment of the method 10 illustrated comprises the steps of: [0162] a) introducing a charge of material or product item or combination of material or product items into a treatment vessel at 11; [0163] b) introducing one or more charges (or a continuous flow) of at least one working fluid into the treatment vessel at 12; and then

[0164] undertaking a treatment regime to at least partially breakdown the charge of material or product item or combination of material or product items, the treatment regime including a plurality of cycles of two stages, namely a first stage of increasing pressure in the treatment vessel to above atmospheric pressure at 13 and then subsequently depressurising the treatment vessel to achieve a pressure reduction in the vessel at 14.

[0165] Importantly, the treatment of the material or product item or combination of material or product items may be achieved by increasing pressure of the material or product item or combination of material or product items in the treatment vessel to above atmospheric pressure and then subsequently depressurising of the material or product item or combination of material or product items in the treatment vessel. In this context, the introduction of the charge of material or product item or combination of material or product items to be treated and the working fluid into the treatment vessel may occur at the same time.

[0166] The at least partially broken-down material or product item or combination of material or product items can then be removed from the treatment vessel at 15.

[0167] The method can be used to treat a material or product item, a combination of materials or product items of the same material, a combination of materials or product items of different materials or even materials or product items which are embedded in or located on a carrier product such as a filter element for example, with only limited, or without any, adverse effect on the carrier product. Further, the method can operate to remove or separate a material or product item or combination of material or product items from a carrier product.

[0168] The treatment of a single type of material or product item (or made of a single material) will normally allow better targeting of the operational parameters to achieve a more efficient or more complete breakdown of the material or product item or combination of material or product items.

[0169] In the preferred embodiment, the breakdown of the material or product item or combination of material or product items also achieves at least some size reduction of the material or product item or combination of material or product items and/or decomposition of the material or product item or combination of material or product items.

[0170] The material or product item or combination of material or product items are preferably loaded into a treatment vessel in which the method takes place. The material or product item or combination of material or product items can be loaded into the vessel in any way.

[0171] The method may take place on a discrete basis, batch basis or a continuous basis. Where the method is implemented on a continuous basis, it is preferred that the material or product item or combination of material or product items will have a particular residence time in the treatment chamber to effect at least partial breakdown. The treatment chamber for continuous treatment may be elongate such as a pipe, duct, manifold, channel or similar. Smaller-scale treatments may be undertaken on a batch basis, larger scale treatments may be continuous or hybrid processes.

[0172] As mentioned above, the material or product item or combination of material or product items can be introduced into the treatment vessel in any way. For example, the material or product item or combination of material or product items may be conveyed into the treatment vessel either mechanically or using a fluid. The material or product item or combination of material or product items may be conveyed into the treatment vessel contemporaneously with or even by the at least one working fluid. In one preferred embodiment, the material or product item or combination of material or product items may be fed into the treatment vessel using gravity.

[0173] In a batch process, once the material or product item or combination of material or product items have been introduced into the treatment vessel, the treatment vessel is then closed and sealed.

[0174] In certain preferred embodiments such as continuous treatment, the treatment vessel may be sealed at all times, and the material or product item or combination of material or product items introduced and removed from the treatment vessel whilst the treatment vessel is still sealed.

[0175] In one embodiment, the treatment vessel may be or include an elongate treatment vessel such as a pipe for example allowing both treatment of the material or product item or combination of material or product items and conveying of the material or product item or combination of material or product items through a treatment zone contemporaneously. In other words, the material or product item or combination of material or product items is treated as they are conveyed into, through and out of the treatment vessel.

[0176] The treatment vessel may therefore be sealed at any time relative to the other steps in the method, provided that it is sealed before the treatment regime begins. In another embodiment the treatment vessel or pipe/duct may not be sealed at any of or all stages in the process.

[0177] The material or product item or combination of material or product items may be pre-treated before introduction into the treatment vessel. In a particularly preferred embodiment, the material or product item or combination of material or product items may be screened prior to introduction into the treatment vessel to remove larger items for further size reduction prior to treatment. In one preferred embodiment, larger material or product item or combination of material or product items may undergo size reduction prior to introduction. Size reduction will typically act to increase the surface area relative to volume of the material or product item or combination of material or product items prior to treatment which will typically shorten the processing time.

[0178] The introduction of the material or product item or combination of material or product items into the treatment vessel will preferably ensure that the material or product item or combination of material or product items may be located or placed in a particular location within the treatment vessel substantially centrally, spaced from the side walls of the treatment vessel. In another embodiment they may be located in a non-central position to optimise the treatment process or allowed to move freely around the treatment vessel or zone.

[0179] A mount may be provided within the treatment vessel for location of the material or product item or combination of material or product items. The mount is preferably a mesh mount to hold the material or product item or combination of material or product items without unduly occluding any parts of the material or product item or combination of material or product items, as that will adversely affect the treatment of those parts.

[0180] In a preferred embodiment, breakup of the material or product item or combination of material or product items leads to size reduction of the treated material or product item or combination of material or product items such that the smaller sized, at least partially broken up material or product item or combination of material or product items can fall through a mesh mount. The openings in the mesh may be sized to allow a particular size fraction of at least partially broken up material or product item or combination of material or product items to pass. This configuration of introduction of the material or product item or combination of material or product items into the treatment vessel and preferably removal of the material or product item or combination of material or product items using gravity may minimise the number of moving parts of the complexity of the introduction and removal process.

[0181] Based on the size reduction or the material or product item or combination of material or product items, the working fluid may then be used to fluidise the at least partially broken-down material or product item or combination of material or product items, to then convey the at least partially broken-down material or product item or combination of material or product items through and/or out of the treatment vessel.

[0182] The treatment vessel of the preferred embodiment is a variable volume vessel. The volume of the treatment vessel can be adjusted prior to introduction of the material or product item or combination of material or product items according to the type and/or size of material or product item or combination of material or product items to be treated. The treatment vessel volume may be fixed volume across the treatment regime.

[0183] As mentioned above, method of the present invention may be used to treat material or product item or combination of material or product items introduced into the treatment vessel.

[0184] The method of the present invention may also be used to treat material or product item or combination of material or product items which is embedded in or located on the useful product such as for example a filter element that carries waste product dirt or filtered material by placing the filter element (as an example) into, or connecting to, the treatment vessel and/or pressurisation/depressurisation arrangement. The method of the present invention may be used to break material or product item or combination of material or product items down in situ on or in a product to be cleaned and remove the material or product item or combination of material or product items from an item such as a filter element. If used in this way, the method will not adversely affect the product to be cleaned, simply at least partially breaking down and preferably removing the material or product item or combination of material or product items from the product to be cleaned.

[0185] The method may utilise any one or more working fluids. The size of the charge of working fluid is adjusted to suit the size of the charge of the material or product item or combination of material or product items.

[0186] The working fluid is gaseous rather than liquid although the working fluid may include a mixture of phases such as steam for example.

[0187] The working fluid may include a mixture of materials. The working fluid may include at least one active component and at least one carrier for example one or more reactants and/or one or more solvents provided with at least one carrier.

[0188] One simple working fluid is atmospheric air with all of its components, including a percentage of water vapour.

[0189] The working fluid may be steam and any percentage of water vapour may be used.

[0190] The working fluid may include one or more chemically volatile substances to complement and/or replace any one or more of the components, such as for example any one or more of the components of atmospheric air.

[0191] The cycle of increasing the pressure and decreasing the pressure in the treatment vessel maybe an adiabatic cycle, where any temperature increase caused by pressurisation through adiabatic heating may be offset by the adiabatic expansion in the depressurisation stage of the cycle which may cause the temperature to drop through adiabatic cooling. Overall, it may be preferred that each cycle does not result in any appreciable temperature rise in the treatment vessel.

[0192] The particular composition of the working fluid for any treatment regime is dependent upon the material or product item or combination of material or product items to be treated. For example, materials based on organic components such as plastic bottles for example, may be better treated by a working fluid which includes at least one organic component or organic solvent provided in atmospheric air carrier typically with steam.

[0193] In one form, a portion of the working fluid is used in a bypass, purge or exit the treatment vessel without being subject to the full process cycle or undergoing full pressurisation and/or depressurisation through at least one bypass, purge or exit arrangement connected to an outlet of the treatment vessel, apparatus or process arrangement. The bypass, purge or exit configuration may utilise the Bernoulli effect or Venturi effect to assist with removal of the working fluid and/or material or product item or combination of material or product items from the treatment vessel. The volume of working fluid in the feed compared to the volume in the bypass, purge or exit is adjustable.

[0194] The working fluid may be injected into the treatment vessel which would agitate the atmosphere in the treatment vessel and may purge any existing atmosphere from the treatment vessel.

[0195] An inlet is provided into the treatment vessel for the working fluid and an inlet is provided for introduction of the material or product item or combination of material or product items into the treatment vessel. A single inlet for both the material or product item or combination of material or product items to be treated and the working fluid may be provided although the illustrated preferred method has the material or product item or combination of material or product items introduced first and the working fluid charge introduced thereafter.

[0196] An outlet is provided into the treatment vessel for the working fluid and an outlet is provided for introduction of the material or product item or combination of material or product items into the treatment vessel. Although a single outlet for both the material or product item or combination of material or product items to be treated and the working fluid may be provided, FIG. 1 shows that the working fluid can be removed separately at 16 and recycled 17 to the introduction step 12.

[0197] The working fluid exit stream and/or at least partially broken-down material or product item or combination of material or product items exit stream can be treated to recover the working fluid and/or any material that can be used to generate or complement the working fluid.

[0198] Each treatment regime will depend on the particular material or product item or combination of material or product items to be at least partially broken down. As mentioned above, each treatment regime is divided into a number of cycles of a pressurisation stage followed by a subsequent rapid depressurisation stage. Once the material or product item or combination of material or product items has been treated according to the treatment regime, then the treatment is completed and the material or product item or combination of material or product items (and working fluid) removed from the treatment vessel (although this can be monitored for effectiveness and shortened if necessary).

[0199] The pressure changes in the treatment vessel according to an embodiment are implemented mechanically, by varying the size of the working volume in the treatment vessel, with a reduction in the working volume in the treatment vessel in order to increase pressure and an increase in working volume in the treatment vessel in order to reduce the pressure in the treatment vessel.

[0200] In one embodiment, the treatment vessel is associated with a pair of pistons. A first piston is provided to adjust the working volume of the treatment vessel prior to treatment.

[0201] The first piston is adjustable to optimise the working volume of the treatment vessel prior to and during treatment and then may maintain the working volume over the treatment regime. The first piston has an associated threaded adjustment mechanism or similar arrangement to adjust the working volume and then manage the working volume.

[0202] The second piston is provided to change the size of the working volume in the treatment vessel to increase the pressure and decrease the pressure during the treatment regime. The second piston is movable preferably reciprocally movable, using a mechanism in order to control the pressurisation and depressurisation of the treatment vessel.

[0203] The increase in pressure may be achieved using any appropriate way. Some pressurisation methods and apparatus may have synergistic effects that go beyond pressure increase. Mechanisms such as heating may be used to increase pressure. Heating may have an additional synergistic effect of not only increasing the pressure but also heat treating of the material or product.

[0204] Heating may be used to augment the operation of the apparatus and/or as a primary mechanism to increase the pressure.

[0205] Heating may be provided in successive treatment vessels and/or zones. Heating may be provided repeatedly in a process vessel.

[0206] The decrease in pressure may be achieved using any appropriate way. Some depressurisation methods and apparatus may have synergistic effects that go beyond pressure decrease. Mechanisms such as cooling may be used to decrease pressure. Cooling may have an additional synergistic effect of not only decreasing the pressure but also treating of the material or product.

[0207] Cooling may be used to augment the operation of the apparatus and/or as a primary mechanism to decrease the pressure.

[0208] Cooling may be provided in successive treatment vessels and/or zones. Cooling may be provided repeatedly in a process vessel.

[0209] Pressurisation of the material to be treated (or a mixture containing one or more materials to be treated) may occur through the application of pressure using one or more injectors to create one or more zones of elevated pressure within the treatment duct in which pressurisation takes place and depressurisation occurs when the one or more injectors ceases to apply pressure and/or when the flow of material to be treated (or a mixture containing one or more materials to be treated) through the treatment duct moves the material to be treated (or a mixture containing one or more materials to be treated) out of the elevated pressure zone.

[0210] The pressure may be applied in one or more pulses through one or more injector. Multiple injectors may be provided radially or circumferentially about the treatment duct. Multiple injectors may be provided over the length of the treatment duct. High pressure working fluid may be introduced in pulse(s) via one or more injectors so as to rapidly pressurise a zone in the treatment duct. There may be multiple pulses from single phase injector(s) or multiple phases of injectors. Pressurisation may be achieved within the injector or prior to the injector feed. Depressurisation can be achieved as a result of absence of injector pulse.

[0211] The one or more injector may inject a combustible fluid such as hydrogen which, when mixed with another working fluid entering the inlet port and ignited, results in an increased-pressure shock-wave and the creation of additional substances such as water vapour for example, which may form at least a part of the working fluid.

[0212] An injector may be provided substantially transverse to the direction of the flow through the treatment vessel, at an acute angle relative to the direction of the flow through the treatment vessel, in a counter current direction to the direction of the flow through the treatment vessel or at an angle relative to the counter current direction of the flow through the treatment vessel.

[0213] The number and configuration of injector(s) provide will depend on the treatment regime required. A ring of multiple injectors about the treatment duct can create a treatment zone through which the material must pass. Multiple rings over the length of the treatment vessel can form multiple treatment zones over the length of the treatment vessel.

[0214] One or more injectors can be provided in line within the treatment vessel. This can create a pulsejet configuration treatment vessel. In this configuration, treatment is intermittent, with the pressurisation and expulsion of each charge of working fluid or mixture preferably causing the intake of a fresh charge. The material or product to be treated may remain in position with the working fluid passing though the treatment vessel and/or any treated material exiting the vessel.

[0215] Provision of one or more injectors in a counter current direction to the direction of flow through the treatment vessel will typically increase the turbulence of the flow through the treatment vessel.

[0216] Any one or more injectors may take the form of a tap/valve/injector releasing pressure from an external generator/source/reservoir or may produce the pulse within the injector by mechanical/electro-mechanical/magnetic/piezoelectric/photoelectric/acoustic/ultrasonic/chemical/combustive means.

[0217] A low-pressure zone or vessel may be associated with an outlet of a treatment vessel. The low-pressure zone or vessel may be at or close to a vacuum.

[0218] The duration of the pressurisation stage of each cycle is typically adjustable. The duration of the depressurisation stage of each cycle is typically adjustable.

[0219] The degree of pressurisation is typically adjustable. The degree of depressurisation is typically adjustable.

[0220] The number of pressurisation and subsequent depressurisation cycles in the treatment regime can be varied.

[0221] In a preferred form, the pressurisation stage of each cycle may be longer than the depressurisation stage. The degree of pressurisation may increase in later cycles in the same treatment regime.

[0222] In one preferred form, multiple cycles of a pressurisation stage followed by a subsequent depressurisation stage using a single charge of working fluid will be used.

[0223] In one form, the pressurisation step may include increasing the pressure within the treatment vessel to a pressure above atmospheric pressure and holding the treatment vessel at an elevated pressure before the subsequent depressurisation of the treatment vessel. In a preferred form, the depressurisation step may be followed by a period at a decreased pressure before the pressure is increased again in the treatment vessel.

[0224] The depressurisation of the treatment vessel may be to a pressure which is above atmospheric pressure but below the peak pressure achieved.

[0225] As mentioned above, the depressurisation of the treatment vessel is effected over a shorter time period than the pressurisation step. It is preferred that the depressurisation step be a flash or explosive depressurisation step.

[0226] The treatment regime will preferably include the introduction of a charge of material or product item or combination of material or product items and the introduction of the charge of at least one working fluid. The treatment regime will then typically follow a predetermined pattern and once the treatment regime is complete, the at least partially broken-down material or product item or combination of material or product items either/or the working fluid will typically be exhausted or removed from the treatment vessel.

[0227] The breakdown of the material or product item or combination of material or product items will typically be monitored during the treatment regime. If the treatment is effective before the number of cycles programmed for the treatment regime has been reached, then the treatment regime can be cut short.

[0228] The working fluid may differ for different cycles within the same treatment regime. For example, at least some of the cycles of a treatment regime may take place with atmospheric air as the working fluid and at least some of the cycles of treatment regime may take place with steam as the working fluid and/or release of the cycles of treatment regime may take place with one or more solvents or reactants as or as a part of the at least one working fluid.

[0229] In situations where the working fluid is changed during the treatment regime, any reactive or solvent components of the working fluid are normally used earlier in the treatment regime, particularly in circumstances where a useful product is being treated for removal of dirt or material for example. In a preferred configuration, one or more later cycles will include steam and/or atmospheric air in order to flush or remove any material formed from the earlier use of reactive or solvent components of the working fluid.

[0230] The one or more embodiments are described above by way of example only. Many variations are possible without departing from the scope of protection afforded by the appended claims.