WO2006100191A1

WO2006100191A1 - Equipment for shredding, moistening and feeding precise quantities of solid hospital waste or other products into suitable sterilization containers

Info

Publication number: WO2006100191A1
Application number: PCT/EP2006/060668
Authority: WO
Inventors: Sandro Gazzaniga
Original assignee: Elkins Anstalt
Priority date: 2005-03-25
Filing date: 2006-03-13
Publication date: 2006-09-28
Also published as: ITGE20050023A1

Abstract

What is described is a top-loading wheeled shredding mill with a horizontally moving ram (4) and with shredding units (7, 107 and 8, 108) opposite this ram. The loading chamber (2) of the mill is provided with an upper preliminary chamber (19) which is sealed from the outside by the waste loading means before the top hatch (3) of the loading chamber of the said mill is opened in this preliminary chamber. On completion of loading, and only after the said top hatch has reclosed, the said feed means can return to the low position to collect further waste, and the said preliminary chamber opens. The shredded waste is fed by gravity to an underlying conveying and remixing system, preferably of the screw type (20, 21), which feeds the said waste to the lower initial part of a second, upwardly inclined, screw conveyor (30) in such a way that any liquid present in the waste remains in the lower part of this conveyor and can be distributed uniformly over all the waste in transit. The waste is subsequently moistened to the correct degree inside the sterilization containers (34), by suitable means (39) located in the piston of the station (33) for loading these containers.

Description

TITLE:

"Equipment for shredding, moistening and feeding precise quantities of solid hospital waste or other products into suitable sterilization containers"

DESCRIPTION

The invention relates to improvements to a part of the machine described in the international patent application published on 13-1 -2005 under the number WO 2005/002639, which is particularly suitable for microwave sterilization of solid hospital waste, in such a way that this waste can be disposed of directly at its source, in the same way as ordinary waste, with costs which are considerably smaller than those of the present methods of disposal using specialized structures. To make the objects of the invention clearer, it should be noted that the method described in this patent application is characterized by the following sequence of operating steps: a) Fine shredding of the waste, on its own or together with its collecting container, in a controlled environment, to prevent leakage of contaminants towards the outside; b) Suitable moistening of the mass of shredded waste, using water; c) Placing and compacting a precise quantity of shredded and moistened waste in open-topped treatment containers, which are transferred to the next processing steps by conveyor means; d) Sealing of each treatment container and its connection to a microwave source of suitable power, which heats the waste and the moisture contained in the said container to create steam and all the conditions of temperature, time and pressure required to ensure the sterilization of the said waste. In this step, the internal pressure of the container is regulated with a controlled discharge, in order not to exceed predetermined maximum values, and after this treatment step the container is conveniently depressurized and reopened; e) Discharge of the sterilized waste from the treatment containers, cleaning of the said containers if necessary, and their return to the operating cycle. During the experimental application of this method, the following problems were encountered in the first stations of the machine which implemented steps a), b) and c):

1. The first station was provided with a waste shredding mill, with a lateral opening for its cyclic feeding with the loads of waste to be shredded, as a result of which, in the cyclic steps of resupply with new waste, the soiled inner walls of the loading chamber of the said mill were in communication with the external environment and could therefore promote the leakage of pollutants. The invention is designed to overcome this drawback by using a shredding mill which is open at the top and has an upper preliminary chamber which is sealed from the outside by the waste loading means before the top hatch of the loading chamber of the said mill is opened in this preliminary chamber. On completion of loading, and only after the said top hatched has reclosed, the said feed means can return to the low position to collect further waste, and the said preliminary chamber opens.

2. The loading chamber of the prior art mill was provided below with walls closely converging towards the shredding system which comprised a rotor with blades which interacted with fixed counter-blades. The load of waste fed cyclically to the mill was pushed towards the lower shredding system by a ram with a vertical travel and by the constant action of gravity. If particularly tough materials were fed into such a mill, the lower shredding system, which is provided with protection using torque control, frequently jammed, and even if the operating programme included automatic freeing steps, with the cyclic reversal of the direction of rotation of the rotating blades, these steps frequently failed to give the desired results since the hard material, even if momentarily freed by the reversing of the rotation, was kept by gravity and by the downwardly converging space between the blades of the shredding system, causing the problem to recur in the next step. The invention is designed to overcome these drawbacks with a mill provided with a loading chamber with a top hatch which can be opened for the introduction of the load of waste to be treated, and provided below, under the said top hatch, with a substantially horizontal wall onto which the cyclically fed waste falls. On one side of the said loading chamber there is provided a vertical ram, operated by a horizontal actuator, which on command pushes the fed waste towards the opposite side on which the rotating blade and fixed counter-blade shredding means operate, more than one of these means preferably being present, for example two, and these means preferably being located on an inclined plane, and being operable by a single motor with torque control. Of the two shredding means, only the lower one discharges the material, shredded to the correct particle size, to the outside, while the upper shredding means returns the shredded material to the chamber. If one of the two shredding systems jams, the ram is retracted and the two rotors of these systems reverse their rotation, in such a way that the material freed from the upper rotor passes to the lower rotor and the material freed from the lower rotor is removed and transferred to the horizontal base wall of the loading chamber, with the certainty that this material will be presented in different conditions from the preceding ones between the shredding means, thus increasing the possibility of its being shredded when these means are made to rotate in the correct direction and when the ram is moved in the working direction.

3. In the first station of the machine described in the patent application cited in the introduction, the shredded waste was collected by a conveyor belt on which it was moistened by suitable means and then fed to subsequent cylinder and piston means which loaded predetermined quantities of waste into the sterilization containers. This solution proved to be inefficient since, if drip bags with liquid residues were present in the waste, they inevitably modified the moistening of the resulting waste in an uncontrollable way when the said bags were shredded. The invention is designed to overcome these drawbacks by having the shredded waste fed to a conveyor system, of the screw type for example, which feeds the said waste to the lower initial part of a second, upwardly inclined, screw conveyor, in such a way that any liquid present in the waste remains in the lower part of this conveyor and can be distributed uniformly over all the waste in transit. The waste is subsequently moistened to the correct degree inside the sterilization containers, by suitable means located in the piston of the station for loading these containers.

4. In the prior art machine, when maintenance of the first station becomes necessary, it is impossible to ensure hygienic conditions of intervention and rapid intervention for the operator. The invention is designed to overcome this drawback by having the first station mounted on a wheeled structure and provided with both upstream and downstream sealing means, in such a way that, when maintenance intervention is required, this station can be disconnected from the machine, replaced quickly if necessary with a new operating station, and then transferred to a more suitable location for sterilization and for the necessary repair and/or inspection.

Further characteristics of the invention, and the advantages derived therefrom, are made clearer by the following description of a preferred embodiment, illustrated by way of example and without restrictive intent, with reference to the eight attached sheets of drawing, in which:

- Fig. 1 is a perspective view of the shredding station in question, with the loading hopper of the mill without the upper compensation chamber and without the means for cyclically feeding the loads of waste; - Fig. 2 shows the station of Figure 1 , in section along the line N-Il, perpendicularly to the axis of rotation of the two shredding rotors;

- Fig. 3 shows other details of the station of Figure 2, in section along the line Ill-Ill, parallel to the axis of rotation of the two shredding rotors;

- Fig. 4 shows other details of the station of Figure 2, in section along the line IV-IV; - Figs. 5, 6, 7 and 8 show from the side, and partially in section, the successive operating steps of the means which cyclically feed the waste into the loading hopper of the mill of the station in question, with a compensation chamber which prevents the communication of the said hopper with the outside;

- Fig. 9 shows the station of Fig. 3, in section along the line IX-IX, and connected for operation to the means which load the waste into the sterilization containers and correctly moisten it;

- Fig. 10 shows in a side elevation, and partially in section, the device with the shutter which cuts off the discharge outlet of the means for loading the waste into the sterilization containers; - Fig. 1 1 shows a perspective view of the cam of the operating device of the shutter of Figure 10;

- Figs. 12 to 18 show, partially in section, the successive operating steps of the means which feed the waste into the sterilization containers and moisten it;

- Figs. 19 to 20 show in a side view and partially in section the steps of the return to the closed position of the shutter for cutting off the discharge outlet of the means for loading the sterilization container.

With reference to Figures 1 to 4, it will be seen that the shredding station according to the invention is mounted on a strong wheeled structure 1 and is provided with the aforesaid upstream and downstream sealing means, in such a way that it can be disconnected rapidly, and in hygienic conditions for the operator, from the sterilization machine, can be replaced if necessary with another operating station, and can be transported to a suitable place to be sterilized and subjected to the necessary maintenance in its turn. On the wheeled structure 1 there is mounted a chamber 2 with a rectangular plan, and with a height which is suitably greater than the height of the loads of waste which are to be cyclically fed into it; as stated above, this waste may be in the collecting containers, which are also disposable, or may be loose. In an end portion only, the chamber 2 is open at the top over its whole width, to form the entry port for the loads of waste, and this port is normally closed and sealed by a hatch 3 which can swing about its pivot 103 which is connected to mechanisms 203 and to a servo control system (not shown) which at the correct time can move this hatch from its low closed position to the raised open position, and in the opposite direction, as stated above.

As shown in Figure 2, the chamber 2 has a substantially horizontal wall 102 under the port with the hatch 3, the waste cyclically fed to this chamber falling onto this wall. On the left-hand side of the chamber 2, a vertical ram 4 is placed in its rest position, at a point suitably set back from the hatch 3, so that there is no interference with the cyclically fed loads of waste, at least the sides and lower edge of the ram being located at a short distance from the walls and base of the chamber 2, the ram being fixed to the ends of a pair of cylindrical horizontal rods 5 which slide in corresponding guide bushes 105 fixed to the rear wall of the chamber 2, on which there is also fixed, between these guides, the body of a linear actuator 6, of the male and female thread type for example, driven by an electric motor 106, preferably of the type with electronic speed and phase control (see below). Under the action of the actuator 6 and under the control of the said guide means 5, 105, the ram 4 is made to carry out short translational forward movements towards the left-hand side of Figure 2, followed by short retraction movements, with constant control of the torque of the motor 106 (see below), until it has completed its maximum travel as indicated in broken lines, to push the waste towards the part of the chamber 2 located to the right of the base wall 102, and having a base which is inclined upwards, for example with an inclination of approximately 45°, engaged by a pair of rotors 7 and 8, which may for example have identical characteristics, and which are positioned with their axes parallel to each other transversely in the chamber 2 by which they are supported rotatably in bearings 9, as shown in the detail in Figure 3, which also shows how the lower rotor is driven by a reduction unit 10 with a motor with torque control, how the two rotors are interconnected at their other ends by means of a transmission 11 , and how the said rotors hold the cutting blades 12 which are arranged in helices with a plurality of starts, so as to provide a progressive cut when these blades interact with sets of fixed counter-blades 107 and 108, the first of which is located on the end part of the horizontal wall 102, while the other is located between the two rotors which, during the normal operating cycle, rotate in an anti-clockwise direction with respect to Figure 2.

Under the upper rotor 8 there is located a curved closed casing 13, so that the shredded material transported by the blades of this rotor returns to the inside of the chamber 2 and is transferred to the action of the lower rotor 7, under which is positioned a perforated curved casing 14 in the form of a sieve, allowing the passage of only those particles of shredded waste having a particle size not exceeding 8-10 mm.

If, during the normal operation of the rotors 7 and 8, the motor of the reduction unit 10 detects a value of torque in excess of that which indicates the jamming of one of the two rotors, the ram 4 is appropriately retracted and the said motor of the unit 10 is temporarily made to rotate in reverse, in such a way that the rotors 7 and 8 of Figure 2 both rotate in the clockwise direction. As a result of this reversing, any material freed from the unit 8, 108 is transferred to the lower rotor 7 which is not rotating in the shredding direction, while any material freed from the lower unit 7, 107 is thrown on to the fixed blades 107 or on to the wall 102, the whole procedure being carried out in such a way that when, in a subsequent step, the rotors are made to rotate in the anticlockwise direction and the presser 4 is returned to its active translational movement towards the rotors, the freed material is presented to the shredding blades in a markedly different configuration from the preceding one, thus increasing the ability of the equipment to return to the normal operating cycle.

Clearly, the presence of the comminution unit 8, 108 at a level above that of the comminution unit 7, 107 facilitates the shredding of the whole height of the mass of waste loaded cyclically into the chamber 2 and moved by the ram 4, especially since the upper rotor 8 tends to push the said waste downwards. As shown in Figure 2, the lateral wall 202 of the chamber 2, towards which the ram 4 pushes the waste, is appropriately reinforced on the outside by suitable ribs. By contrast with what is illustrated, it is possible for this wall 202 not to be vertical as shown, but to be appropriately inclined with a suitable convergence towards the hatch 3, so as to impart a downward thrust component to the waste which is pushed against it by the ram 4. With reference to Figure 5, it will be seen that the waste feed means are located on the side of the chamber 2 opposite that on which the swinging pivot 103 of the top hatch 3 is positioned, these feed means comprising a vertical blade 15 pivoted above at 1 15 on the top of the chamber 2, for example parallel to the said pivot 103 and connected to an actuator 16 which on command can make this blade swing upwards and downwards, as stated above. A shelf 215 is positioned on the blade 15 so that it projects from it and is in a position suitably elevated above its lower edge, this shelf interacting with the end part of a horizontal conveyor (not shown), which at the correct time positions on it a container C holding the waste to be disposed of. On the outermost side of the shelf 215 there is provided an L-shaped arm 17, rotatable on an axis 1 17 perpendicular to the blade 15 which carries externally a small actuator 18 which can make the said arm 17 swing from the downwardly orientated position indicated in broken lines to the upwardly orientated position, in such a way that this arm can be positioned laterally with respect to the container C which is fed in, to retain it correctly on the shelf 215. In subsequent operating steps, as shown in Figure 6, the actuator 16 causes the blade 15, carrying the container C, to rotate upwards, and after approximately 90° of rotation the sides and lower edge of the blade 15 interact and form a seal with the sides and the curved upper wall of a preliminary chamber 19, which is fixed with a seal to the top of the chamber 2, and inside which is located the hatch 3 which, as shown in the sequence of Figures 6 and 7, is made to open, in such a way that, as the blade 15 continues to rotate upwards, the waste in the container C can be introduced into the chamber 2 while being completely sealed from the outside, the waste usually being enclosed in a bag of plastics material, or even in the same container if, as shown in Figure 8, the container is released by the arm 17 which swings upwards, as indicated in broken lines, and is allowed to fall into the chamber 2. When the waste feed is completed, the blade 15, with or without the empty container C, is made to swing progressively downwards, and before this blade leaves the preliminary chamber 19 the hatch 3 is made to close, and only when this closing is completed the said blade 15 is returned to the initial position of Figure 5, for another operating cycle. Clearly, the feeding of the waste into the chamber 2 through the preliminary chamber 19 prevents any communication of the said chamber 2 with the outside, thus preventing even the smallest leakage of pollutants.

As shown in Figures 2 and 3, the waste leaving the grid 14 is collected by a chamber 20 with walls diverging downwards, which prevent the formation in this chamber of bridges of ground material, especially if the material is moist, and on the inclined base of this chamber there rotate two screws 21 parallel to each other, which partially penetrate each other and which are supported at one end by supports with bearings 22 flanged on one side of the said chamber 20 (Figs. 3 and 4), from which the shafts of these screws project for mechanical interconnection by means of the transmission 23, while one of these screws receives its motion from the shaft of the lower shredding rotor 7 by means of another transmission 24. The number 25 indicates a protective casing of the transmissions 23, 24 and 11 , while in Figure 2 the number 26 indicates a wall which covers the casing 13 and the counter-blades 108 and extends to the outside of the chamber 20. It should be understood that, in a variant construction, the small descending chamber 126 formed by the wall 26 can communicate with the chamber 20.

The chamber 20 is provided longitudinally with longitudinal projections 27 for conveying the remixed material moved by the screws 21 towards the lateral discharge outlet 28 which, by means of a connecting joint 29, is connected removably to the lateral outlet 130 of the screw conveyor 30 of a subsequent station which carries out the steps of feeding the waste into the sterilization containers and its controlled moistening, and which can be supported by its own support means (see below). If the aforesaid first shredding station malfunctions, it is simply necessary to remove the joint 29 and close the outlets 28 and 130 with suitable plugs which are provided, to enable the said first station to be removed with its wheeled support structure 1 , and equally simple and rapid manoeuvres can be used to replace this station with a new operating station. In a possible development of the invention, the screw conveyor 30 can also be mounted on the wheeled structure 1 and can be provided with a quick-release connector for the connection of its discharge outlet to the aforesaid subsequent means, in such a way that, if the first operating station has to be replaced, the conveyor 30 can remain associated with this station and it is unnecessary to release and remove the aforesaid joint 29, particularly since polluting liquids can accumulate in the chamber 20 and would inevitably leak out.

The screw conveyor 30 is driven by its own movement unit 31 having a motor with torque control, has its discharge outlet suitably inclined upwards, and is provided with internal longitudinal guides 230 for the upward transport of the material moved by its screw. During the upward transport by the screw conveyor 30, the waste is sufficiently squeezed and drained by the action of gravity, and therefore any liquid entering the first station with the waste is distributed and is dispersed uniformly in the said waste conveyed by the means 30, which in the present example is fixed to the shredding station by means of the aforesaid joint 29 and is fixed with a collar clamp 132 to a support structure 32 having one end 232 fixed to the frame of the machine and having a suitable adjustable foot 332 bearing on the ground. As shown in Figure 9, the discharge outlet 330 of the screw conveyor 30 is connected to a lateral intermediate aperture 133 of the vertical chamber 233 of a batch feeder 33, this chamber terminating below in a tapered mouth 333 having a diameter such that it can fit into the upper mouth of an underlying sterilization container 34 carried by the carousel 35 by means of vertical guides 36 and subject to the action of an elevator means 37, as described in the patent cited in the introduction. The batch feeder 33 comprises a cylindrical piston 433, movable axially in the chamber 233 and controlled by an anti-rotation key 733, this piston being connected to an actuator 533, of the male and female thread type for example, driven by an electric motor 633 with electronic speed, phase and torque control, for example a brushless motor, controlled by the processor 38 which controls the automatic operation of the sterilizing machine. On the base of the piston 433 there is provided at least one nozzle 39, of conical shape and diverging downwardly for example, connected to a feed pipe 139, for example a flexible pipe, which emerges from the top of the said piston 433 and which is connected, for example, to a winding collector 40 which is fixed to the chamber 233 and which in turn is connected to a controlled water feed unit 41 , which is also controlled by the processor 38.

The operation of the batch feed and moistening unit in question will now be described with reference to Figures 12 to 18. After the container 34 has been raised and on completion of its connection to the lower mouth 333 of the batch feed chamber 33, the piston 433 which is stationary in its low position, closing the lateral aperture 133 for communication with the conveyor 30, which is currently stationary, is made to move downwards into the said container 34, as indicated in broken lines in Figure 12, so as to detect the presence of any residual waste in the container, due for example to a preceding interruption in the operation of the machine or an anomalous operation of the station for discharging the said containers 34 after the sterilization step. If the piston 433 completes the predetermined full downward movement into the container 34 without encountering obstacles, this means that the container is empty and ready for a normal refilling cycle. On the other hand, if the piston 433 encounters obstacles in its downward movement, as detected by the torque control of the motor 633, the processor 38 recognizes the presence of waste in the container 34 and allows for the presence of this waste when preparing the refilling cycle for this container. In a subsequent operating step, the piston 433 returns to the high position, thus unblocking the aperture 133, as shown in Figure 13, and the screw conveyor 30 is actuated according to a predetermined program, usually on a time basis, controlled by the processor 38, in such a way that a predetermined quantity of waste is introduced into the container 34 through the chamber 233. In a subsequent step, as shown in Figure 14, the screw conveyor 30 is stopped and the piston 433 is made to move downwards, so as to compact the waste R1 previously fed into the container 34, the height of the layer of waste being controlled by means of the torque control of the motor 633 which drives the piston. The processor 38 then causes a precise elevation of the piston 433, as shown in Figure 15, and then causes the activation of the unit 41 , in such a way as to distribute a quantity of water, correlated with the quantity of waste in the first layer R1 , uniformly over the first layer of waste through the nozzle 39. The piston 433 is then raised again as shown in Figure 16, for the introduction of a new quantity of waste R2 into the container 1 ; for the sake of simplicity, this is assumed to be the final quantity which is necessary to complete the loading of the container 34. In the next step, as shown in Figure 17, the screw conveyor 30 stops and the piston 433 completes its downward movement, now exerting a sufficient pressure to bring the whole load of waste to a predetermined upper point, so that, when the piston 433 is then raised slightly as shown in Figure 18, a predetermined upper portion of the container 34 is clear of the waste. In the step of Figure 18, the whole assembly connected to the nozzle 39 is activated to distribute a predetermined quantity of liquid over the final layer of waste R2. After the step of Figure 18, the container 34 with the predetermined load of waste, correctly moistened, is lowered by the actuator 37 and is returned to rest on the carousel 35, in the position of the initial step of Figure 9, so that it can then be transferred by the carousel to the subsequent sterilization station.

By contrast with the description of the patent application cited in the introduction, the batch feeder 33 is provided with means which, when idle, close the lower mouth of its chamber 233, so as to prevent the accidental dispersion of traces of waste onto the carousel and onto the underlying containers in transit, and to provide a hygienic closure of the said batch feeder in case of removal and/or during maintenance operations. These closing means consist of a flat horizontal shutter 42 shown in Figures 9 and 10, mounted, with the interposition of springs 142 which tend to push it upwards, on the end of an arm 43 keyed onto the lower end of a vertical shaft 44, supported with the possibility of axial movement by a support 45 fixed laterally to the chamber 233, which also supports a small reduction unit 46 with a reversible electric motor, which drives a pinion 144 keyed onto the said shaft 44 with an axially grooved coupling, so as to permit a precise axial movement of this shaft. On the upper end of the shaft 44 there is keyed a cam 47 with a circular plan, shown also in greater detail in Figure 11 , provided with a lower upwardly diverging conical part 147 and with a subsequent upper upwardly converging conical part 247, with a suitably rounded equatorial rim 347 at the junction between the said two conical parts. When the shutter 42 is in the raised position for closing the chamber 233, as shown in solid lines in Figure 10, the lower conical part 147 of the cam 47 interacts with a radial sprung pin 48 mounted on the support 45, in such a way that the said shutter is kept in the raised position for closing the batch feeder 33. When the chamber of the batch feeder has to be opened below to enable a sterilization container 34 to be connected to its lower mouth 333, as stated above, the reduction unit 46 is activated to rotate the shaft 44 in the correct direction to withdraw the shutter 42 from the said chamber, and when this withdrawal is completed a recess 49 of the cam 47 is positioned next to the pin 48, and the shaft 44 descends through a predetermined distance, as shown in broken lines in the said Figure 10. When a sterilization container 34 has been lowered at the end of its filling cycle, as stated above with reference to Figure 18 and as shown, for example, in Figure 19, while the chamber 233 of the batch feeder remains closed by the piston 433 in the low position, the reduction unit 46 is activated to bring the shutter 42 below the chamber 233, as shown in broken lines in the said Figure 19, without interfering with the lower edge of this chamber, because it is in the low position. In the next step, as shown in Figure 20, the container 34 loaded with waste is raised by its lower actuator with a predetermined movement such that the upper edge of this container touches the arm 43 and raises the shutter 42 against the lower mouth 333 of the batch feeder, while the equatorial rim 437 of the cam 47 is moved above the height of the sprung pin 48, which interacts with the lower conical portion 147 of this cam and pushes the whole assembly upwards with the force required to keep the said shutter 42 in the position for closing the underside of the chamber 233, with partial compression of the spring 142. After this step, the container 34 loaded with waste can be finally lowered onto the carousel 35 of Figure 9, which then transfers it to the subsequent operating station. It is to be understood that the carousel 35 can be replaced with any other means capable of transferring the sterilization containers between the different operating stations of the machine. It is also to be understood that, in a variant construction, both the screw conveyor 30 and the batch feeder 33 can be mounted on the wheeled structure 1 , so as to be movable jointly with the first shredding station, without any need for the operator to carry out special and hazardous disconnection operations.

Claims

1 ) Equipment particularly suitable for shredding solid hospital waste or other products to be sent to any subsequent processing cycle, characterized in that the chamber (2) of the waste shredding station is provided with a top opening closed by a hatch (3) located within a preliminary chamber (19) which is sealed from the outside by the waste loading means, before the said top hatch (3) is opened, provision being made to ensure that, on completion of the waste loading, and only after the said top hatch has been reclosed, the said feed means can return to the low position to collect more waste, thus opening the said preliminary chamber (19).

2) Equipment according to Claim 1 , characterized in that the waste feed means are located on the side of the chamber (2) of the waste shredding station, for example on the side opposite that on which the swinging pivot (103) of the top hatch (3) for opening and closing the said chamber is positioned, these feed means comprising a vertical loading blade (15), pivoted above on the top of the said chamber (2), on a pivot (115) which for example is parallel to the said pivot (103) of the hatch and connected to a swinging actuator (16), a shelf (215) being positioned on this blade (15) so that it projects from it and is in a position suitably elevated above its lower edge, this shelf interacting with the end part of a horizontal conveyor, which at the correct time positions on this shelf a container (C) holding the waste to be disposed of, programming means being provided which, when a container has been loaded on to the shelf, activate the actuator (16) to swing the blade (15) carrying the said container (C) upwards, and to ensure that after approximately 90° of rotation the said blade (15) is made to interact and form a seal, by means of its sides and its lower edge, with the sides and the curved upper wall of a preliminary chamber (19), which is fixed with a seal to the top of the said chamber (2) of the shredding station, and inside which is located the top hatch (3) of this chamber, which is made to open by suitable means, in such a way that, as the loading blade (15) continues to rotate upwards, the waste in the container (C), usually enclosed in a bag or in the container itself if it is left free to fall, can be introduced into the shredding chamber (2) while being completely sealed from the outside, the said programming means being such that, when the waste has been fed in, the blade (15), with or without the empty container (C), is made to swing progressively downwards, and before this blade leaves the preliminary chamber (19), the top hatch (3) is made to close and the said blade (15) is then returned to the starting position of its operating cycle.

3) Equipment according to Claim 2, characterized in that there is provided, on the farthest projecting side of the shelf (215) of the loading blade (15), an arm (17), L- shaped for example, designed to rotate on a shaft (1 17) perpendicular to the said blade (15) which carries externally a small actuator (18) which can make the said arm (17) swing from the upwardly orientated position to the downwardly orientated position, in such a way that this arm can, respectively, be positioned on a side of the container (C) with the waste loaded onto the shelf (215), to retain it correctly on the shelf, or move away from this container to allow it to enter the said shelf initially, or allow it to fall into the shredding chamber (2) when the said loading blade (15) is in the position at the end of the upward swing.

4) Equipment according to Claim 1 , characterized in that the chamber (2) of the waste shredding means has a height which is appropriately greater than that of the loads of waste which are cyclically introduced into it and is provided, below the top loading hatch (3), with a lower wall (102) which is substantially horizontal, onto which falls the waste that is fed in, a vertical ram (4) controlled by horizontal guide and slider means (5, 105) being provided in an idle position on one side of this loading chamber, to the side of the said hatch, the ram being driven according to a precise program by a horizontal actuator (6) which, on command, gradually pushes the waste that has been fed in towards the opposite side, on the lower and suitably upwardly inclined part of which there operate the shredding means with rotating blades (7, 8) and fixed counter-blades (107, 108), positioned parallel to each other and orthogonally to the direction of movement of the said ram, and preferably driven by a single reduction unit (10) having a motor with torque control.

5) Equipment according to Claim 4, in which the actuator (6) for driving the ram (6) is, for example, of the male and female thread type, or an equivalent type, and is driven by an electric motor with electronic speed, phase and torque control.

6) Equipment according to Claim 4, characterized in that, of the two shredding means, only the lower one (7, 107) discharges the material, shredded to the correct particle size, to the outside, through a suitable perforated lower casing (14), while the upper shredding means (8, 108) is delimited below by a closed curved casing (13) which returns the shredded material to the shredding chamber (2).

7) Equipment according to Claim 6, characterized in that the said shredding means and the perforated curved casing (14) located under the lower shredding unit (7, 107) are such that they allow the downward passage of shredded waste with an average particle size of not more than 8-10 mm.

8) Equipment according to Claim 4, characterized in that it comprises means by which, if one of the two shredding systems (7, 107 and 8, 108) becomes jammed, the ram (4) is made to withdraw and the two rotors (7, 8) of these shredding systems are temporarily made to rotate in reverse, in such a way that the material freed from the upper rotor passes to the lower rotor and the material freed from the lower rotor is removed from the rotor and passes onto the lower horizontal wall (102) of the loading chamber, with the certainty that the said material will be presented in different conditions from the preceding ones between the shredding means, with an increased possibility of being shredded when the rotors (7, 8) are caused to rotate once again in the correct direction for shredding the waste and when the active working movement of the ram (4) is resumed.

9) Equipment according to Claim 1 , characterized in that the lateral wall (202) of the chamber (2) of the shredding means, against which the ram (4) pushes the waste to be shredded, is suitably reinforced externally by ribs, this wall being positioned vertically or being suitably inclined with a precise convergence towards the top hatch (3), in such a way as to impart a downward thrust component to the waste which is pushed against it by the said ram (4).

10) Equipment according to Claim 6, characterized in that the comminuted waste leaving the grid (14) is collected by an underlying chamber (20) with downwardly diverging walls, which prevent the formation in this chamber of bridges of comminuted material, and on the inclined base of this chamber there rotate two screws (21 ) parallel to each other, which partially penetrate each other and which are supported at one end by supports with bearings which are flanged on one end of the said chamber (20) and from which the shafts of these screws project for mechanical interconnection by means of the transmission (23), while the shaft of one of these screws receives its motion from the shaft of one of the shredding rotors (7) by means of another transmission (24).

1 1 ) Equipment according to Claim 10, in which the said chamber (20) is provided longitudinally with longitudinal projections (27) for conveying the remixed material moved by the screws (21 ) towards the end discharge outlet (28) of the said chamber, which, by means of a connecting joint (29), is connected removably to the lateral outlet (130) of the screw conveyor (30) of a subsequent station which carries out the steps of feeding the waste into the sterilization containers and its controlled moistening, and which can be supported by its own support means (32), provision being made to ensure that, if the first shredding station malfunctions, it is simply necessary to remove the said joint (29) and close the said outlets (28, 130) with suitable plugs which are provided, to enable the said first station to be removed, and equally simple and rapid manoeuvres can be used to replace this first station with a new operating station. 12) Equipment according to Claim 1 , in which the chamber (2) of the waste shredding station is mounted on a wheeled structure (1 ) in such a way that it can be easily and quickly interfaced with the subsequent processing stations of the sterilizing machine or can easily be separated and removed from these for any necessary maintenance or replacement.

13) Equipment according to Claim 1 1 , characterized in that, in a variant construction, the screw conveyor (30) can also be mounted on the wheeled structure (1 ) of the first waste shredding station and can be designed for the quick-release coupling of its discharge outlet to the subsequent operating means, in such a way that, when the first operating station has to be replaced, the said conveyor (30) can remain associated with this first station, thus avoiding the removal of the said joint (29) and the possible leakage therefrom of polluting liquids which may accumulate in the said lower chamber (20) with the first screws (21 ) for remixing and conveying the comminuted waste.

14) Equipment according to Claim 1 1 , in which the said screw conveyor (30) is driven by its own movement unit (31 ) having a motor with torque control, has its discharge outlet suitably inclined upwards, and is provided with internal longitudinal guides (230) for the upward transport of the material which is sufficiently squeezed and drained in this step by the action of gravity as well, as a result of which any liquid entering the first shredding station with the waste is distributed and is dispersed uniformly in the said waste conveyed by this screw conveyor (30).

15) Equipment according to Claim 1 1 , characterized in that the upper discharge outlet (330) of the screw conveyor (30) is connected to a lateral intermediate aperture (133) of the vertical chamber (233) of a batch feeder (33), this chamber terminating below in a tapered mouth (333) having a diameter such that it can fit into the upper mouth of an underlying sterilization container (34) carried by the carousel (35) by means of vertical guides (36) and subject to the action of its own elevator means (37), a cylindrical piston (433), being movable axially in the said chamber (233) with anti-rotation means (733), this piston being connected to a linear actuator (533), of the male and female thread type for example, driven by an electric motor (633) with electronic speed, phase and torque control, for example a brushless motor, controlled by the processor (38) which controls the automatic operation of the sterilizing machine, at least one nozzle (39) being provided on the base of the said piston, this nozzle being of conical shape and diverging downwardly for example, and connected to a feed pipe (139), which emerges from the top of the said piston (433) and which is connected, for example, to a collector (40) which is connected to a controlled water feed unit (41 ), which is also controlled by the said processor (38).

16) Equipment according to Claim 15, characterized in that it comprises programming means such that, after the sterilization container (34) has been raised and its upper mouth has been connected to the lower mouth (333) of the chamber (233) of the batch feeder (33), the piston (433) which has been stationary in its low position in which it closes the lateral aperture (133) for communication with the conveyor (30), which is currently stationary, is made to move downwards into the said container (34), so as to detect the presence of any residual waste in the container, the arrangement being such that, if the piston (433) completes the predetermined full downward movement into the container (34) without encountering obstacles, this means that this container is empty and ready for a normal refilling cycle, whereas, if the said piston (433) encounters obstacles in its downward movement, as detected by the torque control of the motor (633), the processor (38) recognizes the presence of waste in the container (34) and allows for the presence of this waste when preparing the refilling cycle for this container, the arrangement being such that, in a subsequent operating step, the piston (433) returns to the position of maximum elevation to unblock the lateral aperture (133) through which the screw conveyor (30), actuated according to a predetermined program, usually on a time basis, controlled by the processor (38), feeds a predetermined quantity of waste into the container (34). 17) Equipment according to Claim 16, characterized in that it comprises programming means such that, when a first quantity of waste has been fed into the container (34), the screw conveyor (30) is stopped and the piston (433) is made to move downwards, so as to compact the waste previously fed into the said container (34), the height of the layer of this waste being controlled by means of the torque control of the motor (633) which drives the said piston, the arrangement then being such that the said piston (433) is slightly raised and the unit (41 ) is activated, in such a way as to distribute a quantity of water, correlated with the quantity of waste in the first layer, uniformly over the first layer of waste through the nozzle (39) of the piston, the said piston (433) then being raised for the execution of a new step of feeding waste into the sterilization container.

18) Equipment according to Claim 17, characterized in that it comprises programming means such that, during the pressing of the final layer of waste (R2) in the sterilization container (34), which completes the loading of the said container, the piston (433) completes its downward movement, exerting a sufficient pressure to bring the whole load of waste to a predetermined upper point, so that, when the said piston (433) is then raised slightly, an upper portion of the container (34) having a predetermined height is clear of the waste, the whole assembly connected to the nozzle (39) then being activated to distribute a predetermined quantity of liquid over the final layer of waste, after which the container with the predetermined load of waste, correctly moistened, is lowered by its actuator (37) and is returned to rest on the means (35) of transfer to the subsequent sterilization station.

19) Equipment according to Claim 15, characterized in that the batch feeder (33) is provided with means which, when idle, close the lower mouth of its chamber (233), so as to prevent the accidental dispersion of traces of waste onto the underlying carousel and onto the containers in transit, and to provide a hygienic closure of the said batch feeder in case of removal and/or during maintenance operations. 20) Equipment according to Claim 19, characterized in that the said closing means comprise a flat horizontal shutter (42), mounted, with the interposition of springs (142) which tend to push it upwards, on the end of an arm (43) keyed onto the lower end of a vertical shaft (44), supported with the possibility of axial movement by a support (45) fixed laterally to the chamber (233) of the batch feeder, which also supports a small reduction unit (46) with a reversible electric motor, which drives a pinion (144) keyed onto the said shaft (44) with an axially grooved coupling, so as to permit a precise axial movement of this shaft, a cam (47) with a circular plan being keyed on the upper end of this shaft (44), and being provided with a lower upwardly diverging conical part (147) and with a subsequent upper upwardly converging conical part (247), with a suitably rounded equatorial rim (347) at the junction between the said two conical parts, the arrangement being such that, when the said shutter (42) is in the raised position for closing the chamber (233), the lower conical part (147) of the said cam (47) interacts with a radial sprung pin (48) mounted on the said support (45), in such a way that the said shutter is kept in the raised position for closing the lower mouth of the batch feeder (33).

21 ) Equipment according to Claim 20, characterized in that it comprises programming means such that, when the chamber of the batch feeder (33) has to be opened below to enable the upper mouth of a sterilization container (34) to be fitted into its lower mouth (333), the said reduction unit (46) is activated to rotate the shaft (44) in the correct direction to withdraw the said shutter (42) from the said chamber, and when this withdrawal is completed a recess (49) of the said cam (47) is positioned next to the said pin (48), and the shaft (44) and the shutter descend through a predetermined distance.

22) Equipment according to Claim 21 , characterized in that it comprises programming means such that, when a sterilization container (34) has been lowered at the end of the filling cycle, while the chamber (233) of the batch feeder (33) remains closed by the piston (433) in the low position in which it blocks the aperture (133), the said reduction unit (46) is activated to bring the shutter (42) below the said chamber (233), without interfering with the lower edge of this chamber, because it is in the low position, the arrangement being such that, in the next step, the container (34) loaded with waste is raised by its lower actuator with a predetermined movement such that the upper edge of this container touches the said arm (43) and raises the shutter (42) against the lower mouth (333) of the batch feeder, while the equatorial rim (437) of the cam (47) is moved above the height of the sprung pin (48), which interacts with the lower conical portion (147) of this cam and pushes the whole assembly upwards with the force required to keep the said shutter (42) in the position for closing the underside of the chamber (233), with partial compression of the spring (142), the arrangement being such that, after this step, the container (34) loaded with the waste can be finally lowered onto the underlying means (35), which then transfers it to the subsequent operating station.

23) Equipment according to Claim 15, characterized in that the batch feeder (33), as well as the screw conveyor (30), can be mounted on the wheeled structure (1 ) of the first shredding station, so as to be movable jointly with this first operating station, without any need for the operator to carry out special and hazardous disconnection operations.