Device for treating medical waste

Abstract

The invention relates to a treatment device (1) for treating medical waste, the device comprising: - a feed means (2); - a grinding or shredding means (4); and - a heat treatment means (6) for the ground or shredded waste. The heat treatment means (6) comprises at least one duct (8, 10) for conveying the waste, the duct being made of conductive material so as to be able to heat by induction. The heat treatment means (6) also comprises multiple inductors mounted around all or a portion of the duct along the duct. The treatment device (1) comprises control means which are configured to individually control each of the inductors of the heat treatment means (6) so as to raise the temperature of the crushed or shredded waste in a first portion and then maintain the temperature of the waste in a second portion.

Description

Medical waste treatment device

[0001] The present invention relates to the field of medical waste treatment. The invention relates more specifically to devices for treating medical waste by applying heat.

[0002] It is known to treat medical waste, such as infectious healthcare waste, by applying heat. The purpose of heat is to destroy viruses and bacteria present in medical waste, before it is treated in a conventional process or before it is recycled.

[0003] There are devices with electrical resistances that can heat waste to disinfect it. However, such devices remain relatively simple and inefficient in terms of thermal treatment efficiency and energy losses, particularly due to high thermal inertia.

[0004] WO2012 / 03507 relates to a machine for disinfecting medical waste, comprising, in particular, counter-rotating augers using friction to grind and heat the waste, before extruding them by thermal friction in order to heat the ground waste to the desired temperature. However, friction heating, i.e. by mechanical action applied directly to the waste, remains delicate and difficult to control precisely.

[0005] Document FR 2 996 469 B1 concerns a waste treatment machine in which the waste is heated by microwaves. However, using microwaves to heat the waste results in significant energy consumption due to substantial energy losses. In addition, there is also greater wear and tear on the machine over time.

[0006] Document EP 3 053 603 relates to a waste treatment machine, comprising infrared and inductive heating means. In particular, document D4 provides for the addition, in the middle of the waste to be treated, of particles of magnetic materials intended to be heated by the inductor(s) before or during their contact with the waste, then their recovery by a magnet, which complicates the treatment process and makes it more expensive, for limited final efficiency.

[0007] Thus, none of the devices described in the documents cited above allows for precise and rapid control of the heat supplied to the waste, while limiting thermal losses.

[0008] The present invention aims to solve the various technical problems stated above. In particular, the present invention aims to provide a medical waste treatment device having improved operation. In particular, the present invention aims to provide a device having improved reliability and energy consumption, while making it possible to efficiently treat medical waste.

[0009] Thus, according to one aspect, a device is proposed for treating medical waste, in particular waste from healthcare activities with infectious risks, comprising: - a feeding means, - a grinding or shredding means, and - a means for thermal treatment of the ground or shredded waste.

[0010] The heat treatment means comprises at least one conduit for conveying said waste, said conduit being made of conductive material so as to be able to heat by induction. The heat treatment means also comprises several inductors mounted around all or part of said at least one conduit, along said at least one conduit.

[0011] In particular, the treatment device comprises control means configured to individually control each of said inductors of the heat treatment means so as to obtain a rise in temperature of the crushed or shredded waste in a first part of the heat treatment means, then a maintenance of temperature in a second part of the heat treatment means.

[0012] Thus, the treatment device according to the present invention is configured to heat the waste to be treated, then maintain the temperature of the hot waste to be treated, with inductors. More specifically, the treatment device comprises several inductors and control means configured to individually control each of said inductors: it then becomes possible to control, and therefore regulate, precisely and quickly the temperature of the medical waste along its path in the conveying conduit. In particular, the individual control of each inductor makes it possible to limit the risks of local overheating, likely to lead to melting and possibly clogging of the conveying conduit, while guaranteeing the desired temperature rise before maintaining the temperature of the waste.The reduced thermal inertia of such induction heating technology allows for simple and rapid modification of the heat inputs provided at different points in the conveying duct. For example, the control of each inductor can be determined according to the temperature of waste present at the previous inductor, so as to compensate for a lower than expected temperature, or on the contrary, so as not to overheat waste that already has a temperature higher than the desired one.

[0013] Furthermore, the use of inductors to heat waste makes it possible to make the most of electricity consumption, by limiting energy losses during the conversion between electrical energy and thermal energy, while ensuring easy and efficient regulation of the quantities of heat to be supplied locally. Induction heating also provides greater safety to the system, thanks to better control of the energy supplied, as well as improved reliability due to the absence of contact between the inductors and the waste being treated.

[0014] Preferably, the heat treatment means also comprises a conveying means, mounted inside said at least one conduit and configured to convey the crushed or shredded waste from one end to another of the heat treatment means.

[0015] In order to improve the transport of waste in the conduit of the thermal treatment means, a conveying means is provided inside said conduit and makes it possible to move the waste to be treated from the inlet to the outlet of said conduit, limiting the stagnation of waste or the risks of clogging.

[0016] Preferably, the conveying means comprises a worm screw, or a coil with non-joining turns.

[0017] The worm screw and the reel with non-contiguous turns each allow, by simple rotation around their axis of symmetry, to drive in translation along said axis of symmetry, the waste present in the conduit, and more particularly the waste located on the periphery, in contact or in direct proximity with the internal wall of the conveying conduit. The reel with non-contiguous turns is distinguished in particular from the worm screw by the absence of a shaft mounted along the axis of rotation: this provides a less heavy and less bulky conveying means in the conveying conduit, allowing the conveying of a greater quantity of material.

[0018] Preferably, the conveying means also comprises homogenizing elements, for example longitudinal elements such as plates, extending between two successive turns of the coil with non-contiguous turns, or between two successive crests of the worm screw.

[0019] The homogenizing elements are preferably mounted along the axis of rotation of the non-contiguous coil or the worm screw.

[0020] Preferably, the coil with non-contiguous turns is formed from a spiral longitudinal body whose section is circular or elongated, for example rectangular.

[0021] Such a coil makes it possible, in particular, to present a larger drive surface at the level of the internal wall of the conveying duct, in order to improve the drive of waste as it travels through the duct. In particular, the spiral ribbon allows better drive of liquids as well as heavy waste present in the conveying duct.

[0022] Preferably, the turns extend over at least a quarter of the section of the coil, preferably at least a third, and more preferably half.

[0023] As previously mentioned, the non-contiguous coil has no shaft along the axis of rotation, which remains free. Thus, a larger coil width increases the coil's drive surface, and therefore improves the drive of waste into the duct.

[0024] Preferably, the inductors are identical or different.

[0025] The different inductors can be identical, or can have adapted powers depending on their position along the routing conduit, for example at the start or end of the conduit.

[0026] Preferably, the inductors have different lengths, or include coils with different spacings between turns.

[0027] In order to adapt the applied power according to the different zones of the conveying pipe, the inductors may have different structural characteristics, in particular over their length or spacing between turns, in order to obtain a high transmitted thermal power, for example at the start of the conveying pipe, or a lower one, in particular at the end of the conveying pipe. Thus, the inductors and the corresponding powers are configured according to the needs along the conveying pipe, in order to obtain the desired treatment temperature in the waste circulating in said pipe.

[0028] Preferably, the heat treatment means comprises two conveying conduits: a first conduit intended to raise the temperature of the waste, and a second conduit mounted downstream of the first and intended to maintain the temperature of the waste.

[0029] In order to differentiate between temperature rise and temperature maintenance, the heat treatment means may comprise two separate conduits, mounted one after the other, each corresponding to a stage of the two specific stages of the heat treatment. In particular, the conduit positioned first and intended to allow a temperature rise of the waste will be designed and configured to allow a significant conversion of electrical energy into thermal energy, while the conduit positioned second will be designed and configured to control and adjust the temperature of the waste circulating therein, to ensure efficient and correct heat treatment. In particular, the inductors linked to each conduit will thus be adapted and configured to the specific function of said conduit.

[0030] Preferably, the device comprises two heat treatment means supplied by the grinding or shredding means, preferably extending parallel to each other.

[0031] The two heat treatment methods allow for twice the amount of waste to be processed, while maintaining a substantially identical footprint. The ducts of the two heat treatment methods are positioned parallel to each other and allow for faster processing of the waste supplied by the crushing and shredding method. This improves the processing speed of the waste coming out of the crushing and shredding method.

[0032] The figure represents a side view of a medical waste treatment device according to a first embodiment of the invention;

[0033] The represents a top view of the treatment device illustrated in the, and

[0034] The figure represents a top view of a treatment device according to a second embodiment of the invention, with two heat treatment means.

[0035] Figures 1 and 2 illustrate, from the side and from above, a first embodiment of a device 1 for treating medical waste according to the present invention. In particular, the device 1 is intended to treat waste from healthcare activities with infectious risks.

[0036] The device 1 according to the invention thus comprises successively, in a conventional manner, a feed means 2, a grinding or shredding means 4 and a heat treatment means 6 which allow, respectively, to load the waste into the treatment device 1 in order to grind or shred it and then to heat treat it to disinfect it. Such a heat treatment device 1 thus makes it possible to ensure that the treated waste is no longer potentially dangerous, in particular contaminated, with a view to its subsequent treatment or recycling.

[0037] The feed means 2 may for example comprise a chain elevator, configured to lift and empty a container filled with waste to be treated into the crushing or shredding means 4. In particular, the feed means 2 may be configured to cause the container to pivot after it has been lifted, so as to empty its contents into the crushing or shredding means 4 by simple gravity.

[0038] The crushing or shredding means 4 is mounted downstream of the feed means 2 and may in particular comprise a mobile inlet hopper for recovering the waste emptied by the feed means 2, then conventional crushing / shredding elements. Preferably, the crushing / shredding elements are positioned above an inlet of the heat treatment means 6. The crushing or shredding means 4 is preferably oriented vertically, so that the waste supplied by the feed means 2 is directed, by gravity, from the mobile inlet hopper to the crushing / shredding elements, and so that the crushed or shredded waste fragments and residues from the crushing / shredding elements are all conveyed, by gravity, to the inlet of the heat treatment means 6.

[0039] In the embodiment illustrated in Figures 1 to 3, the heat treatment means 6 comprises two successive separate parts, each comprising a conveying duct. However, the heat treatment means 6 can also be produced in a single part, with a single conveying duct.

[0040] Thus, the heat treatment means 6 is separated into two parts corresponding to two distinct stages of the heat treatment: on the one hand, the increase in temperature of the waste to be treated, and on the other hand, the maintenance of the temperature of the waste before its removal from the device 1.

[0041] As illustrated in the figures, each part of the heat treatment means 6 comprises a conveying duct. The heat treatment means 6 therefore has a first conveying duct 8 for increasing the temperature and arranged at the outlet of the grinding or shredding means 4, and a second conveying duct 10 for maintaining the temperature of the heated waste and arranged downstream of the first conveying duct 8. Preferably, the outlet 9 of the first conveying duct 8 is located above the inlet of the second conveying duct 10, so as to allow transfer of the heated waste by the first conveying duct 8 to the second conveying duct 10 by simple vertical drop.

[0042] The first conduit 8 and the second conduit 10 each comprise a conveying means (not shown) and a drive motor 12, 14 for moving the waste inside said conduit. The drive motors 12, 14 are mounted along the axis of rotation of the respective conveying means of the first and second conveying conduits 8, 10, in order to drive them in rotation.

[0043] Preferably, the conveying means is mounted inside each conveying duct in order to convey the crushed waste from one end to the other of the conveying duct in which it is mounted. For example, the conveying means of the ducts 8, 10 may be a worm screw, or a coil with non-contiguous turns. The coil with non-joining turns is distinguished from the worm screw by the absence of a shaft along the axis of the conveying means, which limits the weight and the size of the conveying means in the conveying conduits 8, 10. It is then possible to transport a greater quantity of waste in said conduits 8, 10. In addition, due to its lower weight, the coil with non-joining spirals will also have a lower thermal inertia than that of the worm screw, which allows better reactivity in the heat transfers to the waste to be treated.

[0044] The coil with non-contiguous turns can have different configurations or geometries, depending on the desired properties. Thus, the coil with non-contiguous turns can be formed from a spiral longitudinal body whose section is circular or elongated, for example rectangular.

[0045] Depending on the geometry of the section, the waste entrainment by the coil with non-contiguous turns may differ. For example, a coil with non-contiguous turns with a rectangular section, i.e. in the form of a spiral ribbon, will allow better entrainment of liquids and heavy waste.

[0046] Furthermore, the turns may extend over at least a quarter of the section of the coil, preferably at least a third and more preferably half. Indeed, unlike the worm screw, the coil with non-contiguous turns does not include a shaft along the axis of rotation: there is therefore a space left free at the level of the axis of rotation and only the turns on the peripheral periphery: the turns may therefore have a section extending towards the axis of rotation of the coil, so as to present a larger drive surface.

[0047] The conveying means of the conduits 8, 10 may also comprise homogenizing elements configured to homogenize the waste as it is conveyed along the conveying conduits 8, 10. For example, in the case of a conveying means in the form of a worm screw, or a coil with non-contiguous turns, the homogenizing elements may extend between two successive turns or two successive crests, substantially along the axis of rotation of the conveying means. Such homogenizing elements, for example longitudinal elements such as plates, then make it possible to mix the waste stagnating between two turns or two crests, as the conveying means rotates.

[0048] The heat treatment means 6 finally comprises several inductors 16 making it possible to provide the energy necessary for the heat treatment of the crushed waste. In order to provide thermal energy, the inductors 16 are mounted around the first and second conduits 8, 10 of the heat treatment means 6 which are themselves made of conductive material. Thus, when a current flows in the inductors, they will generate a variable magnetic field inducing currents in the first and second conduits 8, 10 which will themselves generate thermal energy.

[0049] Furthermore, in order to adapt the thermal energy provided by the different inductors 16, said inductors 16 may be identical or different. More precisely, the inductors 16 may have different lengths, or may comprise coils with different spacings between turns. In particular, different types of inductors may be chosen according to their position in the heat treatment means 6: for example powerful inductors (with tight winding) at the first routing duct 8, and less powerful inductors at the second routing duct 10.

[0050] Thus, the heat treatment means 6 comprises both one or more inductors around the first conduit 8 for raising the temperature, and one or more inductors around the second conduit 10 for maintaining the temperature. The heat treatment device also comprises control means (not shown) configured to individually control each of said inductors 16 so as to obtain a supply of thermal energy at the desired locations of the first and second conduits 8, 10.

[0051] Indeed, the inductors make it possible to obtain a transformation of electrical energy into thermal energy which is localized at the level of the inductor, where the magnetic field varies. It is therefore possible to obtain the heat inputs at the desired locations, or even to obtain a temperature gradient between the inlet and the outlet of the first conduit 8 for the rise in temperature of the waste. It is also possible to reduce the heat input when the temperature is higher than that desired, in order to avoid potential melting of the crushed waste and therefore the risk of clogging in the event of mass cooling of the molten material.

[0052] Advantageously, the control means may comprise temperature sensors configured to measure the temperature at different points of the conduits 8, 10 or the temperature at different points inside the conduits 8, 10, in order to allow fine control or regulation of the control of the different inductors.

[0053] The heat treatment means 6 thus makes it possible to obtain the desired thermal energy in the different portions of the heat treatment means 6 so that the temperature profile along the heat treatment means corresponds to the desired one. Above all, the control means and the inductors allow precise and rapid adjustment of the temperature of the crushed waste conveyed inside the conduits 8, 10, according to its evolution over time. It is then possible to guarantee, with a controlled and controlled energy expenditure, the effectiveness of the heat treatment applied to the crushed waste.

[0054] Illustrates a second embodiment of a heat treatment device 1' according to the present invention. In this second embodiment, the heat treatment device 1' comprises two heat treatment means 6, 6'. The two heat treatment means 6, 6' are identical to that described in the first embodiment of the heat treatment device 1 illustrated in Figures 1 and 2, that is to say comprises two conveying conduits equipped with inductors: a first for increasing the temperature and a second for maintaining the temperature. The two heat treatment means 6, 6' are mounted side by side, parallel to each other, with their inlet arranged under the grinding or shredding means 4.Thus, the heat treatment device 1' according to the second embodiment makes it possible to treat, in the same time interval, a quantity twice as large of waste, while having a size similar to that of the first embodiment.

[0055] Thus, the present invention makes it possible to have a simple and efficient heat treatment device, allowing rapid and local regulation to obtain the desired heat treatment, while limiting energy losses. Furthermore, thanks to the use of induction heating both for temperature rise and for temperature maintenance, an overall device is obtained that is more reliable over time, and less subject to breakdowns or clogging, while exhibiting high responsiveness and energy performance.

Claims

Device (1) for treating medical waste, in particular waste from healthcare activities with infectious risks, comprising:- a feeding means (2),- a grinding or shredding means (4)- a means for thermal treatment (6) of the ground or shredded waste,in which the thermal treatment means (6) comprises at least one conduit (8, 10) for conveying said waste, said conduit (8, 10) being made of conductive material so as to be able to heat by induction,in which the thermal treatment means (6) also comprises several inductors (16) mounted around all or part of said at least one conduit (8, 10), along said at least one conduit (8, 10),and wherein the treatment device (1) comprises control means configured to individually control each of said inductors (16) of the heat treatment means (6) so as to obtain a rise in temperature of the crushed or shredded waste in a first part of the heat treatment means (6), then a maintenance of temperature in a second part of the heat treatment means (6)., Device (1) according to claim 1, wherein the heat treatment means (6) also comprises a conveying means, mounted inside said at least one conduit (8, 10) and configured to convey the crushed or shredded waste from one end to another of the heat treatment means (6). Device (1) according to claim 2, in which the conveying means comprises a worm screw, or a coil with non-contiguous turns. Device (1) according to claim 3, in which the conveying means also comprises homogenizing elements, for example longitudinal elements such as plates, extending between two successive turns of the coil with non-contiguous turns, or between two successive crests of the worm screw. Device (1) according to claim 3 or 4, in which the coil with non-contiguous turns is formed from a spiral longitudinal body whose section is circular or elongated, for example rectangular. Device (1) according to claim 5, in which the turns extend over at least a quarter of the section of the coil, preferably at least a third, and more preferably half. Device (1) according to any one of the preceding claims, wherein the inductors (16) are the same or different. Device (1) according to claim 7, in which the inductors (16) have different lengths, or else comprise coils having different spacings between turns. Device (1) according to any one of the preceding claims, in which the heat treatment means (6) comprises two conveying conduits: a first conduit (8) intended to raise the temperature of the waste, and a second conduit (10) mounted downstream of the first and intended to maintain the temperature of the waste. Device (1') according to any one of the preceding claims, comprising two heat treatment means (6, 6') supplied by the grinding or shredding means (4), preferably extending parallel to each other.

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