Methods and apparatus for improving biosafety during waste transport

Abstract

This invention provides a method for encapsulating waste in an inert form. [Solution] A method for encapsulating waste, comprising: (i) depositing a binder composition in a compactor; (ii) placing one or more flexible containers containing waste in the compactor; (iii) heating the binder composition to liquefy it, embedding the waste in the liquefied binder composition to form a coating mixture; and (iv) compacting the coating mixture to form a hydrophobic composite product containing the waste.

Description

Technical Field

[0001] The present invention relates to a method and apparatus for treating waste.

[0002] The present invention particularly, though by no means exclusively, relates to a method for treating mixed hazardous waste into an inert form.

[0003] The present invention particularly, though by no means exclusively, relates to a method for encapsulating mixed medical waste into an inert form.

Background Art

[0004] Over 2 billion tons of municipal solid waste are generated worldwide every year, and at least 33% of these wastes are not managed in a safe manner. This may lead to air pollution, water contamination, and threats to public health. Especially for hazardous waste, toxic waste, or infectious waste originating from the healthcare industry, if medical waste is not properly managed, the risks of infection or injury to communities and leakage of harmful substances into the environment will increase.

[0005] Conventionally, hazardous waste and non-hazardous waste are usually mixed and disposed of in landfills or open dumps. This is still a common practice in some countries.

[0006] Currently, most countries have laws for safe waste treatment. Generally, this implementation involves waste categorization and classification to ensure that various types of waste are properly treated. For example, hazardous waste typically requires thermal / steam treatment, chemical detoxification (treatment of waste with chemicals), incineration, or encapsulation.

[0007] A challenge faced by both thermal treatment and incineration is the treatment of heavy metal contaminated waste. Since heavy metals are usually not easy to volatilize, these heavy metals are eventually incorporated into the ash generated from these treatments.

[0008] It is understood that the release of such ash into the environment poses environmental and health risks. Therefore, providing a method for inactivating such ash would be advantageous.

[0009] Another challenge with incineration is that it is a high-energy-consuming process that often releases harmful chemicals / pollutants.

[0010] To mitigate these problems, technologies have been developed to encapsulate waste with inert substances. Encapsulating materials currently used in this field to coat waste include cement, pozzolanic materials (e.g., silicates), clay, wax, polyolefins, and urea-formaldehyde.

[0011] These methods present numerous challenges. For example, cement-based encapsulation methods produce large and heavy end products, which can be problematic during transportation. Another disadvantage of cement-based encapsulation is that the inherent porosity of the formed concrete makes the end product prone to leaching.

[0012] Currently, urea-formaldehyde is the most widely used material for encapsulating waste from the healthcare industry. However, urea-formaldehyde is fragile and prone to shrinking and cracking during cooling. It is also not water-resistant and easily leaches out.

[0013] U.S. Patent No. 4,021,363 describes a method for immobilizing radioactive particles using a mixture of wax and polyolefin as an encapsulating material. A potential drawback of this method is that encapsulation is insufficient due to inadequate coating.

[0014] It is desirable to provide a method and apparatus for encapsulating waste that mitigates at least one of the problems described above. [Overview of the Initiative]

[0015] The present invention aims to provide a method for encapsulating waste in an inert form, preferably as a composite product for disposal or use for another purpose.

[0016] The composite product may be leachate-resistant. The composite product may be leak-resistant and preferably leak-proof. This reduces the possibility of harmful substances being released from the composite product.

[0017] Preferably, the composite product can be used for other purposes, such as fuel or building material.

[0018] method The present invention provides a method for encapsulating waste using a binder composition, preferably forming a composite product that encapsulates the waste.

[0019] This method may involve the use of a flexible container to hold the waste. The flexible container may be porous or non-porous.

[0020] Waste can be a mixture of different materials.

[0021] Waste may include a mixture of one or more types of harmless waste, hazardous waste, infectious waste, and toxic waste, including contaminated soil. Preferably, waste may be medical waste. Medical waste may originate from hospitals and clinics, as well as other healthcare-related facilities. These include, but are not limited to, dental clinics, general practice clinics, urology and diagnostic laboratories, biological laboratories, blood and sperm donation centers, tattoo studios, veterinary clinics, animal hospitals, and civilian or military medical facilities.

[0022] In this specification, the term “medical waste” refers to waste originating from the healthcare sector, including veterinary medicine, such as infectious waste, biohazardous waste, or toxic waste.

[0023] The waste may be combustible.

[0024] The binder composition may comprise substantially hydrophobic components. Preferably, the binder composition forms a composite product having a hydrophobicity of at least 50%, preferably at least 70%, more preferably at least 90%, even more preferably 100%.

[0025] The substantially hydrophobic components can render the composite product at least water-resistant, and preferably waterproof. This reduces leaching of harmful substances from waste.

[0026] The binder composition may be solid at room temperature.

[0027] The binder composition may comprise either or both of a thermoplastic polymer and a wax. Preferably, the binder composition comprises at least 10 wt% of at least one thermoplastic polymer and up to 90 wt% of wax.

[0028] The binder composition may comprise at least 60 wt% of wax. Preferably, the binder composition comprises wax in the range of 60 wt% to 90 wt%.

[0029] The wax may comprise one or more of the following substances: Fischer-Tropsch wax, polyolefin wax, hydrogenated wax, paraffin, beeswax, lanolin, shellac wax, spermaceti, bayberry wax, candelilla wax, carnauba wax, insect white wax, castor wax, esparto wax, Japan wax, jojoba oil, ouricury wax, rice bran wax, soybean wax, lotus wax, ceresin wax, montan wax, ozokerite, peat wax, microcrystalline wax, petrolatum, substituted amide wax, cetyl palmitate, lauryl palmitate, cetostearyl stearate, polyethylene wax, C30-45 Alkyl Methicone, C30-45 olefin, or any of various hydrocarbons. More preferably, the wax is Fischer-Tropsch wax.

[0030] The binder composition may comprise up to 40 wt% of a thermoplastic polymer. Preferably, the thermoplastic composition comprises 10 to 40 wt% of the thermoplastic polymer.

[0031] The thermoplastic polymer may comprise one or more of the following substances: polyethylene (PE), high-density polyethylene (HDPE), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polypropylene (PP), and copolymers thereof.

[0032] The binder composition may comprise additives. Preferably, the binder composition may comprise additives such as detergents, bactericides, salts, monopotassium phosphate, magnesium oxide, and sulfur. Molten sulfur is particularly suitable for mercury-containing waste.

[0033] The binder composition may be formulated to be one or more types that are chemically stable, capable of adhering to waste, and resistant to biodegradation.

[0034] The present method may comprise the step of pulverizing waste to form pulverized waste. Preferably, the pulverizing step includes any of crushing, grinding, milling, cutting, chopping, and fragmenting the waste. More preferably, the pulverized waste is in the form of a powder, preferably a dry powder.

[0035] The present method may comprise retaining the waste in its original form. This step avoids pulverization of the waste, resulting in energy and cost savings.

[0036] The present method may comprise mixing a thermoplastic polymer and a wax to form a binder composition.

[0037] The thermoplastic polymer in the binder composition may contain recycled materials. Preferably, the thermoplastic polymer substantially comprises waste polymer material. For example, the thermoplastic polymer may be supplied from the packaging industry and may contain waste plastic products such as plastic bags. Preferably, the waste plastic products are not recyclable. This allows non-recyclable waste that would otherwise be destined for landfill to be used for another purpose. Another advantage of using a thermoplastic polymer for the binder is that the final product is lighter compared to the final product formed using cement as the binder, for example.

[0038] This method may include providing a binder composition in the form of fine particles.

[0039] This method may include mixing waste with a liquefied binder composition to form a coating mixture.

[0040] The mixing step may involve coating the waste with the binder composition so that the binder composition binds to the waste. Preferably, the binder composition forms a matrix that encapsulates the waste and any associated hazardous substances.

[0041] This method may include forming a final composite product having up to 80 wt% waste.

[0042] This method may include producing a composite product that is water-resistant and leaching-resistant.

[0043] This method may include forming a recyclable composite product. Preferably, the composite product may be recyclable as a fuel source.

[0044] Composite products may be used as composite building materials.

[0045] The composite building material may contain waste dispersed in a matrix of thermoplastic polymer and wax, and the composite building material may contain about 60% to about 90% by weight of particulate material, with wax present in the matrix in an amount of at least about 25% by weight.

[0046] The composite building material may contain waste dispersed in a uniform matrix of thermoplastic polymer and wax.

[0047] The composite building material may contain waste dispersed in a heterogeneous matrix of thermoplastic polymer and wax.

[0048] The composite building material may contain waste dispersed in a heterogeneous matrix, the heterogeneous matrix comprising particles of a first thermoplastic polymer dispersed in a homogeneous matrix with wax, and particles of a second thermoplastic polymer having a lower melting point than the first thermoplastic polymer and capable of forming a homogeneous matrix with wax.

[0049] In one embodiment, the present invention relates to a method for encapsulating waste using a binder composition, (i) Depositing waste inside a flexible porous container, (ii) To provide a non-porous container for accepting a flexible porous container, (iii) Depositing the binder composition in a non-porous container or in a flexible porous container, (iv) Placing a flexible porous container containing waste inside a non-porous container, (v) Heating the binder composition to liquefy it and forming a coating mixture containing waste embedded in a hydrophobic matrix, (vi) Compressing the coating mixture to form a composite product that encapsulates the waste This provides a method that includes this.

[0050] Step (i) may include a step of crushing the waste to form crushed waste. Preferably, the crushing step includes crushing, grinding, milling, cutting, shredding, and fragmenting of the waste. More preferably, the crushed waste is in the form of a powder, preferably a dry powder.

[0051] Step (i) may include keeping the waste in its original form.

[0052] This method may include mixing a thermoplastic polymer and a wax to form a binder composition for step (iii).

[0053] The thermoplastic polymer of the binder composition in step (iii) may contain recycled materials.

[0054] Step (iii) may include providing a binder composition in particulate form. Preferably, the binder composition is in the form of pellets or beads.

[0055] This method may include placing a flexible porous container inside a porous container. Preferably, the porous container is formed from a rigid material. More preferably, the porous container is a perforated drum. This allows excess dissolved material to be discharged from the flexible porous container.

[0056] A porous container may have perforations formed on its surface. Preferably, the porous container has a perforation base.

[0057] Porous containers may be manufactured from metal, composite fibers, polypropylene, wood, metal-reinforced high-density polypropylene, metal-reinforced silicon, or a combination thereof. Preferably, porous containers are manufactured from stainless steel.

[0058] The porous container may be any suitable shape, such as a cylinder, a rectangular prism, or a truncated cone.

[0059] Step (iv) may include placing the flexible porous container within a nestable porous container within a non-porous container. In this embodiment, the porous container provides means for placing the flexible porous container within the non-porous container.

[0060] Step (iv) may include bringing the porous container into contact with the binder composition in the non-porous container.

[0061] Preferably, the method involves bringing a porous container into contact with a binder composition in a non-porous container.

[0062] The pores of the flexible container may be formed to a size that allows the molten binder composition to be discharged from the container. Preferably, the container has sieve holes or mesh having openings of at least 500 microns.

[0063] Flexible porous containers may be formed from polypropylene (PP), polyethylene (PE), any alternative polymer, any natural fiber, or any synthetic fiber. Preferably, the flexible porous container may be a bag. More preferably, the flexible porous container may be a woven bag or a mesh bag.

[0064] A flexible porous container may be openable and closable to contain its contents. Preferably, the container is equipped with a drawstring to open and close it.

[0065] Step (v) may include heating a non-porous container to liquefy the binder composition and form a molten matrix to coat the waste. Preferably, the method includes providing a hot plate for heating the non-porous container.

[0066] Step (v) may include heating the binder composition such that at least a portion of the porous container is immersed in the liquefied binder composition and the waste is covered.

[0067] This method may include mechanical mixing of a liquefied binder composition with waste.

[0068] Mechanical mixing may involve stirring either or both of the non-porous and porous containers.

[0069] This method may include draining excess binder from the porous container. Preferably, this method includes lifting and removing the porous container from the non-porous container and draining the excess liquefied binder from the porous container.

[0070] This method may include lifting the porous container within the non-porous container to allow for the discharge of excess binder from the porous container. This step may include lifting the porous container above the liquid level in the non-porous container and engaging the fitting members of the porous container with the corresponding members on the non-porous container. This places the porous container above the liquid level of the liquefied binder composition in the non-porous container.

[0071] This method may include compressing a flexible porous container to encapsulate waste and remove excess binder composition.

[0072] This method may involve compressing a flexible porous container and substantially immersing the flexible porous container in a binder composition. Preferably, this method involves compressing the flexible porous container relative to a porous container, making the flexible porous container compact and forming a layer of composite product, the layer of composite product can provide a substrate, on which another flexible porous container may be placed to form another layer of composite product.

[0073] Preferably, the method includes compressing the porous container within the porous container using a manual or automatic pusher.

[0074] This method may include cooling a compressed flexible porous container.

[0075] This method may include compressing a cooled, compressed flexible porous container to form a final composite product.

[0076] The final composite product may form a layer within a porous container that can provide a substrate, on which more flexible porous containers may be placed to form another layer of the composite product within the porous container.

[0077] Steps (i) to (vi) may be repeated to produce a multilayer composite product in a porous container.

[0078] In a further embodiment, the present invention relates to a method for encapsulating waste, (i) depositing the binder composition inside the compactor, (ii) Placing one or more flexible containers containing waste inside the compactor, (iii) Heating the binder composition to liquefy it, embedding the waste within the liquefied binder composition, and forming a coating mixture. (iv) Compacting the coated mixture to form a hydrophobic composite product containing waste This provides a method that includes this.

[0079] At least one of the flexible containers may be non-porous. Preferably, all of the flexible containers are non-porous.

[0080] The thermoplastic polymer of the binder composition in step (i) may include recycled materials. Step (i) may include providing a binder composition in particulate form.

[0081] Step (ii) may include keeping the waste in its original form.

[0082] The waste may be provided in a flexible container by the aforementioned industry or facility. For example, the waste may be delivered in a plastic bag to a processing facility where it is treated and a hydrophobic composite product is formed.

[0083] Step (ii) may include placing one or more flexible containers, each containing waste, inside the compactor.

[0084] After placement in the compactor, the method may include opening one or more flexible containers and releasing the waste before step (iii). For example, one or more flexible containers may be cut using a cutter, preferably a loop wire saw cutter. This facilitates the release of the scattered waste within the compactor and allows for more efficient encapsulation of the waste by the binder composition.

[0085] The flexible container may be formed from polypropylene (PP), polyethylene (PE), or any alternative polymer. Preferably, the flexible container may be a bag. More preferably, the flexible container may be a plastic bag.

[0086] A flexible container may be openable and closable to contain its contents. Preferably, the flexible container is equipped with a drawstring to open and close it.

[0087] The method may include placing the binder composition and one or more flexible containers containing waste through the inlet of a compactor. Preferably, the method includes placing the binder composition and one or more flexible containers containing waste through a chute on the top surface of the compactor. More preferably, the method includes pivotably opening the lid of the chute, placing the binder composition and one or more flexible containers containing waste, and pivotably closing the lid of the chute after step (ii).

[0088] Step (iii) may include heating and liquefying the binder composition to form a molten matrix that coats the waste. Preferably, the method includes providing a hot plate, electric band heater, or any other suitable heating device that can be operated to heat and liquefy the binder composition within the compactor.

[0089] Step (iii) may include heating the binder composition so that at least a portion of the waste, preferably a flexible container, is immersed in the liquefied binder composition.

[0090] This method may include applying mechanical vibration to the liquefied binder composition to strengthen the coating of the waste. For example, the vibration may be provided through mechanical oscillation or by using a pneumatic vibration source.

[0091] The method may include dispersing the liquefied binder composition within a compactor to enhance the coating of the waste. For example, the compactor may be provided with a sprayer or any other suitable dispensing device to enhance the dispersion of the liquefied binder composition on the waste. This facilitates efficient coating of the waste and any flexible container by the binder composition, embedding the waste within the liquefied binder composition. Preferably, the embedding of the waste within the liquefied binder composition forms a coating mixture. More preferably, the coating mixture includes waste embedded in a hydrophobic matrix.

[0092] Step (iv) may include compressing the coating mixture to form a composite product. Preferably, step (iv) includes compressing the coating mixture using a manual or automatic press. In some embodiments, the press is a ram equipped with a scissor arm mechanism. The scissor arm mechanism may be actuated by a hydraulic jack and extend and retract along the length of the compactor.

[0093] During the compression process, the extension of the scissor arm mechanism drives the press, pressing the waste against the walls of the compactor and compacting the coating mixture. Conversely, the retraction of the scissor arm mechanism allows the press to retract. This compression cycle may be repeated as required.

[0094] This method may include cooling the coating mixture, preferably after it has been compressed.

[0095] This method may involve repeatedly compressing a coated mixture, preferably a cooled and compressed coated mixture, to form a hydrophobic composite product.

[0096] The method may include removing the hydrophobic composite product from the compactor through an outlet. Preferably, the method includes pushing the hydrophobic composite product out of the compactor. For example, the composite product is pushed out of the compactor by a press. Preferably, the press is operated by a scissor arm mechanism when the outlet is in the open direction to remove the composite product.

[0097] The compactor's outlet may open automatically in response to a signal from a sensor when a predetermined compression level is reached.

[0098] This method may include cutting the extruded composite product. Preferably, the extruded composite product may be cut using any suitable cutting device, such as a rotary saw or a laser cutter.

[0099] Device The present invention also provides an apparatus for encapsulating waste using the method described above, and preferably for forming a composite product that encapsulates the waste.

[0100] The apparatus generally comprises a flexible container for receiving waste and a binder composition, a heater for liquefying the binder composition and coating the waste with the liquefied binder composition, and a press for compressing the waste and binder composition to form a composite product.

[0101] The device may include a processing unit for receiving waste to be supplied to a flexible container. For example, the processing unit may be a biohazard bin used in the healthcare industry in accordance with regulatory requirements.

[0102] The apparatus may include a crusher for crushing waste. Preferably, the crusher is configured to crush, grind, mill, cut, shred, or fragment the waste before it is placed in a flexible container or coated with a binder composition. More preferably, the crusher is a crusher or grinder.

[0103] In one embodiment, the apparatus for encapsulating waste is (i) A flexible porous container for receiving waste, (ii) A non-porous container for receiving a flexible porous container containing waste, wherein one or more flexible porous containers or non-porous containers are also configured to receive a binder composition for encapsulating the waste, (iii) A heater for liquefying the binder composition and forming a hydrophobic matrix to coat the waste, (iv) Press and It is equipped with.

[0104] A flexible porous container may be a mesh bag.

[0105] This device may be equipped with a porous container for receiving a flexible porous container.

[0106] The porous container may be formed from a rigid material. More preferably, the porous container is a perforated drum. Perforation allows excess molten binder to be discharged from the container.

[0107] A porous container may have perforations formed on its surface. Preferably, the porous container has a perforation base. More preferably, the porous container has a perforation base and side walls.

[0108] Porous containers may be manufactured from metal, composite fibers, polypropylene, wood, metal-reinforced high-density polypropylene, metal-reinforced silicon, or a combination thereof. Preferably, porous containers are manufactured from stainless steel.

[0109] Porous containers may be nestable within non-porous containers.

[0110] The porous container may have at least one fitting member that can engage with a corresponding member on the non-porous container. Preferably, the fitting members of the porous and non-porous containers allow the porous container to be positioned within the non-porous container at at least two levels. This pulls the porous container above the liquefied binder within the non-porous container, allowing excess binder to be discharged from the flexible porous container. More preferably, the at least one fitting member on the porous container may be a ledge or lip that can engage with a step on the inner surface of the non-porous container.

[0111] The porous container may be any suitable shape, such as a cylinder, a rectangular prism, or a truncated cone.

[0112] The heater may be in direct contact with the non-porous container. Preferably, a hot plate is positioned beneath both the porous and non-porous containers.

[0113] The heater can be an electric hot plate.

[0114] This apparatus may include a mixer for mixing the waste and the binder composition.

[0115] The mixer may be any mixing means known in the art. A suitable mixer may be a single-screw or twin-screw extruder.

[0116] A press may be used to compress a flexible porous container inside a porous container.

[0117] A press may be used to compress the mixture inside the porous container when the porous container is lifted and removed from the non-porous container.

[0118] The press may be any press known in the art. Preferably, the press is a manual pusher, an automatic pusher, or a hydraulic press.

[0119] The apparatus may include a mold for forming a composite product from a mixture of a binder composition and waste. Preferably, the composite product is formed after the heat from the molten material has dissipated and the mixture has cooled.

[0120] In another embodiment, the present invention relates to a compactor for encapsulating waste, (i) an entrance for receiving a binder composition and one or more flexible containers containing waste, (ii) A heater for liquefying the binder composition, embedding the waste within the liquefied binder composition, and forming a coating mixture, (iii) Press and compress the coating mixture to form a hydrophobic composite product We provide a compactor equipped with the following features.

[0121] The flexible container may be formed from polypropylene (PP), polyethylene (PE), or any alternative polymer. Preferably, the flexible container may be a bag. More preferably, the flexible container may be a plastic bag.

[0122] The flexible container may be openable and closable to accommodate waste. Preferably, the flexible container is equipped with a drawstring to allow it to be opened and closed.

[0123] The compactor may be formed from a rigid material. Preferably, the compactor is made from metal, composite fiber, polypropylene, metal-reinforced high-density polypropylene, metal-reinforced silicon, or a combination thereof. Preferably, the compactor is made from stainless steel.

[0124] The compactor may have any suitable shape. Preferably, the compactor has an elongated, generally rectangular body.

[0125] The entrance may be in the form of a chute located on the top surface of the compactor. Preferably, the chute has a lid that can be opened to deliver waste into the compactor.

[0126] The entrance may be located in the center of the compactor. This ensures that the binder composition and the flexible container containing the waste are delivered to the center of the compactor.

[0127] The compactor may include a cutter, preferably a wire-based cutter, configured to open a flexible container placed inside the compactor. Preferably, the cutter includes a wire saw. The wire saw may be a continuous loop guided by a pulley configuration. This releases the waste from the flexible container, cuts the flexible container into smaller pieces, and allows for more efficient encapsulation of the waste with a binder composition.

[0128] The compactor may be configured to accept a particulate binder composition. Alternatively, the compactor may be configured to accept a liquid binder composition.

[0129] The heater may be in direct contact with the binder composition. Preferably, the heater is located in the center of the compactor. More preferably, the heater is located at the base of the compactor.

[0130] The heater may be an electric hot plate, an electric band heater, or any suitable heater known in the art.

[0131] The apparatus may include a mixer configured to enhance the coating of the waste with a binder composition. Preferably, the mixer is configured to impart mechanical vibration to the liquefied binder composition. For example, the mixer may be a mechanical vibrator, a pneumatic vibration source, or any suitable mixing device known in the art.

[0132] The mixer may be located in the center of the compactor.

[0133] The apparatus may include a sprayer configured to enhance the coating of the waste with a binder composition. Preferably, the sprayer is configured to disperse the liquefied binder composition onto the waste.

[0134] The sprayer may be positioned in the center of the compactor.

[0135] A mixer or sprayer enhances the coating of the waste and any flexible container with the binder composition, so that the waste is embedded in the liquefied binder composition and forms a coating mixture. Preferably, the coating mixture contains waste embedded in a hydrophobic matrix.

[0136] A press may be used to compress waste embedded in a hydrophobic matrix.

[0137] The press may be any press known in the art. Preferably, the press is a manual pusher, an automatic pusher, or a hydraulic press. More preferably, the press is a ram actuated by a suitable hydraulic drive system. For example, the press is a ram and preferably comprises a scissor arm mechanism actuated by a hydraulic jack. The scissor arm mechanism may be configured to extend and retract the ram.

[0138] The compactor may, advantageously, be designed to facilitate the efficient embedding of waste into the binder composition during compression.

[0139] The compactor may have walls, and the coating mixture is compressed against these walls.

[0140] The compactor may be equipped with a cooler. Preferably, the cooler is configured to cool the compressed coating mixture or to remove heat from the compressed coating mixture to form a hydrophobic composite product. Any suitable cooling device known in the art may be used.

[0141] The compactor is equipped with an outlet, through which the hydrophobic complex product may be removed from the compactor.

[0142] A press may be used to extrude the final hydrophobic composite product from the compactor. For example, the composite product is extruded from the compactor by extending a ram along the length of the compactor towards the exit.

[0143] The exit may be provided with a door, preferably a door hinged along one side, to remove the composite product from the compactor.

[0144] It is understood that the outlet can consist of various sizes and shapes depending on the desired size and shape of the final composite product.

[0145] The compactor may be equipped with a sensor configured to automatically open the outlet door when a predetermined compression level is reached.

[0146] The compactor may include a cutter configured to cut the extruded composite product. The cutter may be any suitable cutting device, such as a rotary saw, blade, or laser cutter.

[0147] The following describes, with reference to the attached drawings, some preferred embodiments of the present invention as merely one example. [Brief explanation of the drawing]

[0148] [Figure 1] This is a cross-sectional view of an apparatus according to a first embodiment of the present invention. [Figure 2] Figure 1 is a cross-sectional view of the apparatus, which comprises a flexible porous container filled with a coating mixture containing waste embedded in a hydrophobic matrix. [Figure 3] Figure 3 is a cross-sectional view of an apparatus according to a second embodiment of the present invention, showing a multilayer composite product. The reference numerals used in Figure 3 are based on the naming convention used in Figures 1 and 2, and are prefixed with "5" (for example, the nonporous container in Figure 3 is labeled 520, while the same element is labeled 20 in Figures 1 and 2). [Figure 4] Figure 3 is a cross-sectional view of the apparatus, showing the discharge of excess binder from the flexible porous container to the non-porous container. [Figure 5] This is a process flow diagram of a method for encapsulating mixed waste using the apparatus shown in Figure 1. [Figure 6] This is a perspective view of a compactor according to one embodiment of the present invention. [Figure 7] Figure 6 is a side view of the compactor. [Figure 8] (a) is a top view of the compactor in Figure 6, and (b) is an end view of the compactor in Figure 6. [Figure 9] Figure 6 is a cross-sectional perspective view of the compactor. [Figure 10] This is a cross-sectional side view of a compactor according to one embodiment of the present invention, showing the placement of bagged waste inside the compactor. [Figure 11] Figure 10 is a cross-sectional side view of the compactor, showing the compression of the waste and liquefied binder composition. For clarity, details of the scissor arm mechanism are omitted. [Figure 12] Figure 10 is a cross-sectional side view of the compactor, showing the extraction of the composite product. For clarity, details of the scissor arm mechanism have been omitted. [Modes for carrying out the invention]

[0149] Figures 1 and 2 show an apparatus for encapsulating waste according to one embodiment of the present invention. The apparatus 10 comprises a flexible porous container 16, a perforated stainless steel drum 18, a non-perforated stainless steel drum 20, a heater 24, and a press 22.

[0150] The perforated stainless steel drum 18 is nested inside a slightly larger non-perforated stainless steel drum 20. The capacities of the perforated stainless steel drum 18 and the non-perforated stainless steel drum 20 can be adjusted according to the desired volume of waste 12 to be encapsulated. The drums 16, 18 may take the shape of a frustoconical, conical, or cylindrical object. The perforated stainless steel drum 18 accepts a solid binder composition 14, which is preferably supplied from waste plastic, and consists of a mixture of wax and a thermoplastic polymer. The binder 14 is preferably in the form of pellets or beads.

[0151] As shown in Figure 1, the porous container, which is in the form of a woven mesh bag 16 made of polypropylene, is placed inside a perforated stainless steel drum 18 on top of a solid binder 14 and is configured to receive waste 12.

[0152] The number of mesh bags 16 placed inside the stainless steel drum 18 may vary depending on the amount of waste 12 being accumulated.

[0153] Figure 2 shows the apparatus of Figure 1, which includes a mechanical press 22 for mixing and compacting the binder-coated waste 12 inside the mesh bag 16. An electric hot plate 24 is positioned directly below a non-perforated stainless steel drum 20, which heats and liquefies the binder composition 14 inside the stainless steel drum 20. As the binder 14 melts, the porous container 18 descends into the molten binder, so that the waste 12 (inside the mesh bag 16) is gradually immersed in the binder molten 14. This provides an efficient method for encapsulating the waste 12 and inactivating hazardous substances within the waste 12.

[0154] The perforated stainless steel drum 18 has holes in its side walls and base to allow any excess binder molten material 14 to be discharged from the perforated stainless steel drum 18 to the non-perforated stainless steel drum 20.

[0155] This can be achieved by raising the perforated stainless steel drum 18 above the liquid level of the liquefied binder 14. A manual press 22 is used to compress the mixture 26 inside the perforated stainless steel drum 18, remove excess binder, and form the final composite product 32. Another advantage of using the press 22 is that it optimizes the amount of binder 14 needed to achieve efficient encapsulation of the waste.

[0156] According to a second embodiment of the present invention, the porous container 518 is provided with an outer side wall fitting member configured to engage with a corresponding member of the inner side wall of the non-porous container 520.

[0157] This embodiment is shown in Figures 3 and 4. In these drawings, the perforated stainless steel drum 518 is provided with a pair of lips 528 extending outward from the outer surface of its side wall, and the non-perforated stainless steel drum 520 is provided with a plurality of protruding steps 530 on its inner wall for engaging with the lips. By positioning the lips 528 relative to the steps, the porous container 518 is nested at a high position within the non-porous container 520, allowing excess binder 514 to be discharged into the non-perforated stainless steel drum 520. The advantage of this configuration is that the manual work required of the user (not shown) during the discharge process is minimized.

[0158] Figure 5 shows the operation of the apparatus 510 for encapsulating mixed medical waste according to the present invention. Although this example focuses on medical waste, it is understood that this method is also suitable for processing other types of waste.

[0159] The first step of this method includes a step 100 for recovering mixed medical waste originating from the healthcare industry, including harmless and hazardous waste, which includes infectious waste, toxic waste, pathological waste, sharp objects, and chemicals, among other things, such as used syringes, bandages, diapers, and surgical scalpels. Suitable sources of waste include hospitals and clinics.

[0160] Typical hospital waste contains up to 15% heavy metals, which are leached and can cause contamination. Therefore, transporting such waste over long distances for disposal incurs significant costs and poses a risk of contamination.

[0161] Advantageously, since the present invention processes mixed waste, there is no need to sort the waste before processing it.

[0162] The mixed medical waste is stored in a large container or any other suitable storage facility before being processed according to the present invention.

[0163] The waste can be reduced in size through crushing and / or grinding processes, but is preferably stored without being crushed.

[0164] The method also includes step 120, which provides a binder composition consisting of a mixture of wax and a thermoplastic polymer supplied from waste plastic.

[0165] Waste plastics may be supplied from the packaging industry and may substantially include waste labels and backing liners.

[0166] Binder composition 514 is controlled to contain approximately 10-40 wt% high-density polyethylene (HDPE). The binder composition is further controlled to contain approximately 60-90 wt% Fischer-Tropsch wax.

[0167] The binder composition 514 is preferably in the form of fine particles and may be powdered or pelletized so that the components are more easily dispersed throughout the medical waste when mixed. In this regard, the waste plastic itself may be treated by crushing and / or dissolving into granular form.

[0168] In step 140, the binder composition 514 is deposited inside the non-perforated stainless steel drum 520. In step 160, a perforated stainless steel drum 518 having a perforated base and side walls is placed inside the non-perforated stainless steel drum 520 and placed on top of the binder composition 514.

[0169] Next, in step 180, a woven polypropylene mesh bag 516 is placed inside the perforated stainless steel drum 518.

[0170] In step 200, the mesh bag 516 is filled with medical waste 512 to an appropriate level.

[0171] In the next step 220, the heating plate 524 is activated to heat the stainless steel drum 520, melting the binder composition 514 and forming a molten matrix that covers the medical waste 512.

[0172] The operating parameters, such as the heating temperature, are modified to homogenize the thermoplastic polymer and wax in the binder composition.

[0173] As the binder dissolves, the perforated stainless steel drum 520 sinks into the liquefied binder 514, and the waste 512 is encapsulated.

[0174] The contents of the mesh bag 516 can be more uniformly mixed in step 240 by agitating the perforated stainless steel drum 518 or the mesh bag 516 inside the drum 518. This ensures that the binder composition 514 comes into contact with the medical waste 512 and ultimately coats most of the medical waste 512.

[0175] The advantage of mixing the waste with the molten binder composition 514 is the vaporization / evaporation of water mixed in the medical waste 512. This eliminates the need to pre-treat the medical waste to remove moisture, for example, by heating, which is energy-intensive, time-consuming, and costly.

[0176] In the next step 260, the perforated stainless steel drum 518 is lifted and removed from the non-perforated stainless steel drum 520, and any excess binder composition 514 (i.e., molten material) is discharged from the perforated stainless steel drum 518 under gravity. This is best illustrated in Figure 4, where the lip 528 of the perforated stainless steel drum 518 is seated on step 530 of the non-perforated stainless steel drum 520. This design allows for a multi-layer setup in which the perforated stainless steel drum 518 fits neatly inside the non-perforated stainless steel drum 520, maintaining interlayer separation while capturing any residue or molten material 514. The discharged molten binder composition 514 may be captured within the non-perforated stainless steel drum 520, recycled, and reused.

[0177] Subsequently, in step 280, the mesh bag 516 containing the medical waste 512 and the slurry of the liquefied binder 514 is compressed against the bottom of the perforated stainless steel drum 518 using a manual pusher 522. This immerses the mesh bag 516 in the molten binder 514, encapsulating the medical waste 512.

[0178] The compression step 280 also reduces the volume of the medical waste 512, allowing it to be encapsulated in less molten binder 514.

[0179] This eliminates the need for a separate, energy-intensive, time-consuming, and costly crushing process to crush and / or grind the waste.

[0180] The compression process 280 can also remove moisture or other fluids from the waste 512.

[0181] After compression, a cooling step 300 is performed to cool the encapsulated waste composite product 532. Those skilled in the art will understand that cooling devices such as blowers may be used to accelerate the cooling of the composite product 532. This results in a leak-proof and leaching-proof composite product 532 in which harmful substances such as viruses, bacteria, and molds bind to the dissolved product 514 and are trapped within the dissolved product 514.

[0182] The cooled and compressed product 532 may undergo a further compression step 320 to form the final composite product 532. In this step 320, the composite product 532 is placed inside a plastic bag, such as a medically approved bag for storing medical waste, and compressed in a mold to form a final product having the desired product shape.

[0183] The process of this method can be repeated as required to form multilayer composite products, for example, as shown in Figures 3 and 4. For example, a new solid binder 514 may be placed on top of the first final composite product 532. An additional mesh bag 516 may be placed inside the perforated stainless steel drum 518 for the waste 512 to be deposited inside.

[0184] The final multilayer composite product is then transported to a target destination and either incinerated, for example, or used for another purpose. Suitable uses of the composite product include its use as a seed material for manufacturing polymers or waxes. Encapsulated composite products may be recycled as a fuel source if the composite product consists substantially of flammable material.

[0185] Therefore, this example of the present invention provides a method for encapsulating and fixing waste to form an inert composite product that is resistant to leakage and leaching of hazardous substances when the composite product is exposed to meteorological elements such as rain.

[0186] Figures 6 to 9 show an apparatus for encapsulating waste according to another embodiment of the present invention.

[0187] This device is a compactor comprising an inlet 36, a heater 38, and a press 40. The compactor 34, manufactured from stainless steel, generally has a rectangular body and includes a central part 44 located between a first end 42 and a second end 46. The inlet 36 is located on the top surface of the compactor 34, and the outlet 48 is located at the second end 46 of the compactor. A hopper 37 is located on the top surface of the inlet 36.

[0188] The lid 50 is hinged along one side of the hopper 37 and is pivotally open and closed.

[0189] The particulate binder composition 52 is fed into the compactor 34 through the hopper 37.

[0190] The binder composition 52 comprises a mixture of wax and waste plastic, mainly consisting of thermoplastic polymers. The binder composition 52 is controlled to contain approximately 10-40 wt% high-density polyethylene (HDPE) and approximately 60-90 wt% Fischer-Tropsch wax.

[0191] The waste 56 is contained within a flexible container, which is in the form of a plastic bag 54. The plastic bag is typically tied with a drawstring or closed to hold the waste 56 in place. The bagged waste 56 may be supplied from healthcare-related facilities, such as hospitals and clinics, and delivered to the site for processing according to the present invention.

[0192] As shown in Figures 8 and 9, these plastic bags 54 containing the waste 56 are placed inside the hopper 37.

[0193] Referring to Figure 10, when the plastic bag 54 containing the waste 56 passes through the hopper 37 and falls into the center 44 of the compactor 34, the continuous loop wire saw 58 cuts through the plastic bag 54, releasing the shredded waste 56 into the compactor 34.

[0194] Once the compactor 34 is filled with the appropriate levels of binder composition 52 and waste 56, the heater 38 is activated. The heater 38 melts the binder composition 52, forming a molten matrix that covers the waste 56.

[0195] The heater may be in the form of a hot plate or electric band heater installed in the center 44 and first end 42 of the compactor 34.

[0196] Operating parameters such as heating temperature may be adjusted to ensure that the thermoplastic polymer and wax in the binder composition 52 are properly homogenized.

[0197] As the binder composition 52 liquefies, at least a portion of the waste 56 and the cut plastic bag 54 comes into contact with the binder composition 52.

[0198] The waste 56 and the contents of the cut plastic bags 54 can be mixed more uniformly by using a mixer 62 to agitate and vibrate the center 44 of the compactor 34. The mixer may be a mechanical vibrator, a pneumatic vibration source, or any suitable mixing device known in the art. This ensures that the binder composition 52 embeds most of the waste 56, ultimately forming the coated mixture 60.

[0199] Subsequently, the covered waste 56 is compressed against the wall of the second end 46 of the compactor 34 using a ram 64. The ram is actuated by a scissor arm mechanism 66 driven by a hydraulic jack 68. The scissor mechanism is best illustrated in Figures 9 and 10.

[0200] Figure 11 shows how the ram 64 is used to compact the covered waste 56.

[0201] When the ram 64 presses the coating mixture, the waste 56 is further immersed in the liquefied binder composition 52. This enhances the embedding of the waste 56 into the binder composition 52.

[0202] The compressed coating mixture generated within the compactor 34 is cooled, forming a hydrophobic composite product. A cooling device may be used to accelerate the temperature drop at the second end 46 of the compactor 34. Preferably, the second end 46 operates at ambient temperature.

[0203] The cooled and compressed composite product is repeatedly compressed using the ram 64 to form the final composite product. During this compression process, the outlet 48 is kept closed to ensure that the composite product is securely held within the compactor.

[0204] Once the desired level of compression is achieved, the final hydrophobic composite product 70 is pushed out through the outlet 48 (see Figure 12).

[0205] The exit 48 is equipped with a hinged door 72, which allows it to move between the open and closed directions.

[0206] The door 72 of the exit 48 may open automatically when a sensor detects that a predetermined compression level has been reached, allowing the composite product to be removed.

[0207] The hydrophobic composite product 70 may be extruded from the compactor 34 and cut into desired shapes and lengths before being delivered to the target location or to the customer.

[0208] Where prior art documents are cited in this specification, it should be understood that such citations do not constitute an endorsement that such documents form part of common knowledge in the relevant field in Australia or any other country.

[0209] In the following claims and the preceding description of the invention, unless otherwise specified by express wording or implicit context, the word “comprise” or variations such as “comprises” or “comprising” is used in a comprehensive sense, that is, to specify the presence of the described features, but does not preclude the possibility that further features may be present or added in various embodiments of the invention.

[0210] Those skilled in the art will understand that many modifications can be made without departing from the spirit and scope of the present invention.

Claims

1. A method for encapsulating waste, (i) depositing a binder composition inside the compactor, (ii) Placing one or more flexible containers containing waste inside the compactor, (iii) Heating the binder composition to liquefy it, embedding the waste in the liquefied binder composition to form a coating mixture, (iv) Compacting the coating mixture to form a hydrophobic composite product containing the waste A method that includes this.

2. The method according to claim 1, wherein at least one of the flexible containers is nonporous.

3. The method according to claim 1, comprising providing a binder composition containing up to 40 wt% of a thermoplastic polymer.

4. The method according to claim 1, comprising mixing a thermoplastic polymer and a wax to form the binder composition.

5. The method according to claim 1, wherein step (ii) comprises cutting the one or more flexible containers and releasing the waste.

6. The method according to claim 1, comprising applying mechanical vibration to the liquefied binder composition to strengthen the coating of the waste.

7. The method according to claim 1, wherein step (iv) comprises compressing the coating mixture using a press that expands and contracts along the length of the compactor.

8. The method according to claim 1, wherein step (iv) comprises repeatedly compressing the coating mixture in the compactor.

9. The method according to claim 1, comprising cooling the coating mixture after it has been compacted.

10. The method according to claim 1, comprising extruding the hydrophobic composite product from the compactor.

11. The method according to claim 10, comprising cleaving the extruded hydrophobic composite product.

12. A compactor for encapsulating waste, (i) an entrance for receiving the binder composition and one or more flexible containers containing the waste, (ii) A heater for liquefying the binder composition, embedding the waste in the liquefied binder composition, and forming a coating mixture, (iii) Press and compress the coating mixture to form a hydrophobic composite product A compactor equipped with the following features.

13. The apparatus according to claim 12, wherein a chute is located at the inlet on the upper surface of the compactor.

14. The apparatus according to claim 12, further comprising a wire-based cutter configured to cut one or more of the flexible containers.

15. The apparatus according to claim 12, configured to impart mechanical vibration to the liquefied binder composition.

16. The apparatus according to claim 12, wherein the press is configured to expand and contract along the length of the compactor.

17. The apparatus according to claim 12, further comprising a cooler for cooling the coating mixture after it has been compressed.

18. The apparatus according to claim 12, wherein the press is configured to extrude the hydrophobic composite product from the compactor.

19. The apparatus according to claim 18, further comprising a cutter for cutting the extruded hydrophobic composite product.

20. The apparatus according to claim 12, wherein at least one of the inlet and the heater is located in the center of the compactor.

Images