EP3467214B1 - Method and device for grinding kitchen waste and/or food remnants - Google Patents

Description

Technical area

The present invention relates to a device and a method for shredding kitchen waste and/or leftover food, preferably for homogenizing kitchen waste and/or leftover food.

Technical background

Organic kitchen waste, such as preparation and cleaning waste, and leftover food, is generated in large quantities every day, for example in commercial kitchens, canteens, hotels, communal catering facilities, other catering establishments and in supermarkets. These organic kitchen waste and food leftovers can be used as a raw material for generating renewable energy in biogas reactors and for producing fertilizers. To do this, it is necessary to treat the organic kitchen waste and leftover food so that it can be stored and transported.

For the disposal and storage of organic kitchen waste, systems are known in which the organic kitchen waste and food leftovers are placed in a disposal device, in which they are shredded using a shredding device in the form of a grinder, sometimes with the addition of water, so that they are then in a largely homogenized form can be pumped into appropriate storage tanks. From these storage tanks, the largely homogenized biomass is then transported by means of a transport vehicle to a biogas plant in which the biomass is fermented, the digester gases resulting from the fermentation, in particular methane gas, being used to generate electrical energy and/or heat energy. In this way, organic kitchen waste can be recycled and renewable energy can be generated from it in an environmentally friendly way. In addition, the remaining, usually thin digestate can be used in agriculture as fertilizer or soil improver.

From the EP 2492405 A1 a device is known in which kitchen waste and food leftovers to be shredded are placed in a funnel-shaped receptacle, at the bottom of which a grinder for shredding the kitchen waste is arranged, which is downstream of a pump. In the operation of the Device, i.e. with the grinder rotating and the pump running at the same time, the kitchen waste and food leftovers are shredded in the grinder and sucked in by means of the pump downstream of the grinder. The suction of the pump creates a suction in the direction of the pump, so that a flow of shredded kitchen waste and food scraps is generated from the grinder in the direction of the pump. Due to the pumping out of the shredded kitchen waste and leftover food, further kitchen waste and leftover food can enter the grinder, so that essentially all of the kitchen waste and leftover food in the receptacle can be gradually shredded and pumped out.

In order to achieve an improved feeding of the kitchen waste and food leftovers in the receptacle to the grinder during shredding and pumping, a pre-shredding unit protruding into the receptacle in the form of a driver provided with shredding knives is attached to a rotor of the grinder, which moves when the rotor rotates rotates synchronously with this. As a result, some of the leftover food and kitchen waste is pre-shredded before it hits the grinder. Due to the volume flow from the grinder towards the pump, uncrushed as well as sticky and fibrous materials get into the grinder and further into the product line connecting the grinder and the pump, which leads to agglomerations of the aforementioned materials and/or blockages in the grinder, the product line and/or or the pump. To avoid this, a more or less large amount of process water is always supplied during operation of the device in order to prevent agglomerations.

The AU 2010200304 A1 shows a system for treating organic waste WO 2012/134289 A1 shows a device for shredding and discharging large household waste and/or medical waste, which EP 2962771 A1 shows a method for controlling a kitchen waste shredder WO 2007/086344 A1 shows a waste treatment device that GB1040699 shows a waste disposal device that EP 1136449 A1 shows a wastewater processing system, and the US 8,584,976 B1 and the US 2016/0040413 A1 each show a kitchen waste shredder for a sink.

Presentation of the invention

Based on the known prior art, it is an object of the present invention to provide an improved method for shredding kitchen waste and/or food leftovers, as well as a corresponding device.

The task is solved by a method for shredding kitchen waste and/or leftover food with the features of claim 1. Advantageous developments of the method result from the subclaims as well as the present description and the figures.

Accordingly, a method for shredding kitchen waste and/or food leftovers, preferably for homogenizing kitchen waste and/or food leftovers, is proposed, comprising the step of loading a funnel for receiving kitchen waste and/or food leftovers, which is attached to a funnel base with a grinder for shredding the Kitchen waste and/or food leftovers are provided and are connected from the grinder via a product line to a pump for pumping out shredded kitchen waste and/or food leftovers kitchen waste and/or food leftovers to be shredded, and the step of pumping out the kitchen waste and/or food leftovers shredded by the grinder using the pump. According to the invention, before the step of pumping out in the funnel, the kitchen waste and/or food leftovers located in the funnel are pre-shredded by means of a pre-shredding unit projecting into the funnel, with the kitchen waste and/or food leftovers being transformed into a homogenized mass in the funnel (2nd) in the pre-shredding step ) is formed, with the pump (5) only being switched on after the pre-crushing step in order to start pumping out.

Because the kitchen waste and/or food leftovers located in the hopper are pre-shredded before the step of pumping out the hopper by means of a pre-shredder unit projecting into the hopper, an improved shredding result can be achieved and the maintenance effort of a device which is operated according to the method , be reduced. The activated pre-shredding unit ensures that the kitchen waste and/or leftover food is already cut and/or smashed in the hopper. Since the pre-shredded kitchen waste and food scraps are not pumped out by the switched off pump during pre-shredding, the kitchen waste and/or food scraps initially remain in the hopper and can be further shredded there.

By pre-shredding the kitchen waste and/or leftover food, the cell structures of this organic waste are already largely shattered in the funnel to such an extent that the water contained in the kitchen waste and leftover food is released in the funnel. Many kitchen waste and food leftovers have a high content of their own water, which is made usable through the pre-shredding step before the kitchen waste and/or food leftovers are shredded in the grinder. This utilization of the water contained in kitchen waste and leftover food reduces the need for externally added process water, which in turn reduces the volume of biomass to be disposed of and thus reduces disposal costs.

In addition, the kitchen waste and/or food leftovers in the hopper are already homogenized in the hopper. Consequently, a homogenized mass, preferably an aqueous suspension with a preferably porridge-like consistency, which is composed of the pre-shredded kitchen waste and/or leftover food as well as the dissolved out water, is already formed in the hopper by the pre-shredding that precedes the pumping out and therefore the crushing by the grinder . The kitchen waste and/or food scraps pre-shredded in this way make it easier for them to be later shredded by the grinder when they are sucked out of the funnel through the grinder due to the onset of the pumping action of the pump.

During the pre-shredding step, the kitchen waste and/or leftover food is already shredded in such a way that a mass that can be pumped out is created. In other words, the mass resulting from the pre-shredding of the kitchen waste and/or leftover food is sufficiently watery and homogeneous that it essentially covers the bottom of the funnel, at least in the area of the grinder, so tightly that a suction generated by the pump extends in the direction of the pump the funnel area in which the aqueous suspension is present, thus extending into the bottom area of the funnel. As a result, the pre-shredded kitchen waste and/or food leftovers or their homogenized suspension are sucked in before the grinder and sucked into the grinder by the resulting stream, so they can be further shredded particularly efficiently. In addition, the occurrence of agglomerations in the grinder can be reduced or even completely avoided due to the current that already begins in the funnel. In particular, the flow distribution created in the grinder is more uniform.

The pre-shredding takes place for a specific period of time before the pump is started. Alternatively, pumping can begin with a manual input or a control command.

According to a further preferred embodiment of the method, during pre-shredding by the pre-shredding unit, a maelstrom circulating in the hopper is generated, the pre-shredding unit preferably generating the circulating maelstrom in the hopper by a rotational movement about an axis of rotation of the pre-shredding unit. The kitchen waste and/or food leftovers in the hopper are therefore additionally stirred or mixed by the pre-shredding unit. This creates a maelstrom in the hopper, which circulates the material in the hopper preferably in a horizontal and at the same time also in a vertical direction.

In the circulating maelstrom generated by the pre-shredding unit, the kitchen waste and/or food leftovers rotate at different speeds depending on their position in the hopper. The closer kitchen waste and/or leftover food is to the pre-shredding unit, the higher its speed. As the distance to the pre-shredding unit increases and the distance to the hopper wall decreases, the speed decreases, with the particles being slowed down in particular by friction on the hopper walls and among each other. The parts or mass flows moving at different speeds as well as the friction between each other cause the kitchen waste and/or food leftovers to be further shredded in the maelstrom, which further increases the pre-shredding or pre-homogenization of the kitchen waste and/or food leftovers already done in the funnel. As a result of the pre-shredding or pre-homogenization, a relatively homogeneous biomass is formed in the hopper, with the entire contents of the hopper gradually being moved through the maelstrom and shredded.

In this process, kitchen waste and food leftovers are preferably crushed so finely that the cell structures of the substances are destroyed, their own water is released and a homogeneous, flowable mass is created.

According to a further preferred embodiment, a predetermined amount of process water is introduced into the funnel and/or into the product line before and/or during the pre-shredding, preferably via a nozzle and/or a water inlet arranged in the funnel and/or in the product line. This can increase the homogenization of the pre-shredded kitchen waste and/or leftover food. In addition, the water content of the mass resulting from the kitchen waste and/or food leftovers through pre-shredding can be increased or adjusted in order to achieve a consistency that is favorable for subsequent shredding in the grinder and pumping out via the pump.

According to a further development, a certain amount of process water is preferably introduced at least into the product line before the start of pre-shredding. The amount is preferably dimensioned such that the product line is completely filled, with the process water filled in preferably reaching up to the upper area of the grinder. On the one hand, this ensures that the pump arranged at the end of the product line can pump fluid directly, and a negative pressure does not have to be generated by displacing air. On the other hand, agglomerations in the grinder and in the product line as well as the pump due to adhesion of powdery, sticky and/or fibrous materials can be avoided. Alternatively, such an amount of process water can be introduced into the product line so that the water level rises above the upper edge of the grinder rotor into the funnel. Particularly for powdery and/or dry materials, this method of water supply has the advantage that the materials receive enough process water even in the lowest zone of the funnel to produce a mass with a mushy, pumpable consistency. In addition, solid substances that are deposited between the blade ring and the rotor of the grinder and thereby potentially block the start of the processing cycle are washed out. In this case, additional process water is introduced into the processing cycle, which slightly increases the water content of the mass produced by pre-shredding based on the pre-shredded kitchen waste and/or food leftovers, but significantly improves process reliability.

The water content of the mass located in the funnel or in the product line is preferably measured using a water content sensor, preferably using an inductive measuring method, a microwave resonance method or a photometric method. Alternatively, other methods for determining the water content can also be used. Based on the results of the water content measurement, additional process water can be added accordingly, preferably until a predetermined water content is present, preferably during pre-shredding. Alternatively or additionally, the process sequence, the duration of the individual steps and/or the total cycle time can be set and/or adjusted based on the determined water content.

In order to prevent non-organic substances such as textiles, plastic articles such as films and/or gloves from getting into the grinder, according to a further preferred embodiment, non-organic substances are separated during the pre-shredding, preferably by entangling and/or winding up the non-organic substances at least a projection, preferably a pre-shredding knife, particularly preferably an at least partially blunt-edged pre-shredding knife, of the pre-shredding unit. In addition, any pumped-out biomass used to produce biogas is less contaminated with inorganic contaminants.

If ferromagnetic substances are sorted out of the kitchen waste and/or food leftovers by applying a magnetic force at least in a region of a funnel wall of the funnel, preferably at least during pre-shredding, as provided in a preferred embodiment of the method, these substances can be prevented block the grinder and cause damage to the pre-shredding unit, the grinder and/or the pump. In addition, any pumped-out biomass used for biogas production is less contaminated with inorganic contaminants. The rotational movement of the pre-shredding unit creates a flow, i.e. the maelstrom, which moves the relatively heavy ferromagnetic materials, such as cutlery items, essentially due to a centrifugal force in the direction of the funnel wall, on which they are held and fixed by the magnetic force.

According to a preferred continuation, the separated substances and/or the sorted out substances are removed from the hopper after the crushing and pumping has been completed. This means that the entire funnel volume is available for refilling with kitchen waste and/or leftover food that needs to be shredded.

According to a further preferred embodiment, in a final phase of pumping out, the funnel and/or a lid covering the funnel during operation is pre-cleaned using injected process water. The process water is preferably injected in the last phase of homogenization when the input funnel is already largely emptied, with the process water preferably being supplied via a nozzle directed at the cover of the input station. This means that the process water is sprayed widely over the biomass still in the hopper and the lid and the hopper area are roughly cleaned.

According to a further preferred embodiment, the pre-shredding unit and/or the grinder rotate at a speed of 700 to 2800 revolutions per minute, preferably at a speed of 1400 revolutions per minute, with the pre-shredding unit and the grinder preferably rotating synchronously. The speed can preferably be set on a corresponding controller or specified by it. The higher the speed of the rotating grinder and the rotating pre-shredding unit, the smaller the particle size created when shredding the kitchen waste and/or food leftovers. The desired particle size of the shredded kitchen waste and food leftovers can be adjusted by controlling the speed. If the particle size is very small, a suspension is formed in which solids and liquid are bound. The resulting mass is then particularly easy to pump and, due to gravity, can flow away in a slightly inclined pipeline in the direction of gravity, which enables the hopper, grinder and/or product line to be almost completely emptied.

In order to achieve an improved shredding and/or mixing ratio or a higher degree of homogenization, the speed of the pre-shredding unit and/or the grinder can be varied following a further preferred development and/or the rotation of the pre-shredding unit and/or the grinder can be interrupted and /or the direction of rotation of the pre-shredding unit and/or the grinder can be reversed. The varying of the speed, the interruption of the rotation and/or the reversal of the direction of rotation preferably take place according to a predetermined time sequence, the sequence preferably being controlled/regulated by means of a controller.

In order to increase the efficiency of the method and reduce the risk of injury to operating personnel, the method can be at least partially automated, with at least the start of the pre-shredding and/or the termination of the pumping preferably taking place automatically, with a sensor signal preferably indicating the start of the pre-shredding and/or or triggers the start and/or stop of pumping.

A sensor is preferably used to determine when the funnel is completely filled or filled to a predetermined value. The level can be determined based on weight, inductively and/or optically. Alternatively, the level can also be measured using other types of sensors that are already known. If the filling of the hopper corresponds to the specified value and/or exceeds it, the sensor emits a corresponding signal, which triggers the start of pre-shredding.

Furthermore, during the pre-shredding, a speed and/or a torque and/or a rotational resistance of a drive driving at least the pre-shredding unit are preferably determined at least in sections or intermittently, preferably continuously. In a continuation, a change over time of at least one of the determined values, preferably the change over time in the torque or rotational resistance, is compared with a predetermined limit value and/or preset value. The aforementioned temporal change can be used as a measure of the degree of homogenization of the kitchen waste and/or food leftovers, whereby if the temporal change is less than the limit and/or default value and/or lies within a predetermined range, then the change resulting from the pre-shredding The mass is sufficiently homogeneous so that it can be pumped out effectively by the pump and simultaneously crushed in the grinder. This can be used as a trigger signal to start pumping.

Furthermore, according to a further preferred embodiment, an empty level of the funnel and/or a liquid level in the product line can be detected, whereby when the empty level is reached and/or the liquid level falls below a predetermined level, an injection or subsequent injection of process water can be triggered or the pumping out can be stopped. The vacancy level can be determined based on weight, inductively and/or optically.

The above object is further achieved by a device for shredding kitchen waste and/or leftover food, preferably for homogenizing kitchen waste and/or leftover food, with the features of claim 10. Advantageous further developments result from the subclaims as well as the present description and the figures.

Accordingly, a device for shredding kitchen waste and/or food leftovers, preferably for homogenizing kitchen waste and/or food leftovers, is proposed, comprising a funnel for receiving kitchen waste and/or food leftovers, a grinder arranged on a funnel bottom of the funnel for shredding, preferably homogenizing , kitchen waste and/or leftover food and a product line a pump connected to the grinder for pumping out shredded kitchen waste and/or leftover food, with a pre-shredding unit extending from the bottom of the funnel into the interior of the funnel being arranged in the funnel for pre-shredding the kitchen waste and/or food leftovers located in the funnel. According to the invention, a control is provided which is set up to control pre-shredding by means of the pre-shredding unit and then switching on the pump for pumping out shredded kitchen waste and/or food leftovers.

“Control” here is understood to mean a device that enables the behavior of technical systems to be influenced in a directed manner both by specifying a default value and by adapting the default value as a result of a returned comparison signal or measurement signal or measuring element. The control is therefore set up to control and/or regulate the device.

Because a controller is provided which is set up to control pre-shredding by means of the pre-shredding unit and then switching on the pump for pumping out shredded kitchen waste and/or food leftovers, the advantages described with regard to the method can be achieved in an analogous manner.

Preferably, at least one funnel wall, preferably all funnel walls, has an inclination of at least 45°, preferably at least 50°, particularly preferably at least 55° and very particularly preferably at least 60° relative to the horizontal. In other words, the funnel wall and the direction of gravitational acceleration form an angle of a maximum of 45°, preferably a maximum of 40°, particularly preferably a maximum of 35° and very particularly preferably a maximum of 30°. The high gradient of the funnel wall makes it possible for the solids and liquids in the funnel or their suspension to flow or move essentially independently towards the bottom of the funnel due to gravity. In order to be able to ensure the self-flow of the aforementioned substances particularly safely, the funnel bottom has an inclination of at least 60° compared to the horizontal.

The pump is preferably connected via a transport line to a tank for receiving and/or storing the shredded kitchen waste and/or leftover food.

According to a further preferred embodiment, at least one sensor is provided for detecting a fill level in the funnel and/or in the product line, the controller being set up to receive a sensor signal from the sensor. The sensor is preferably used to determine if or whether the funnel and/or the product line is complete or is filled to a specified value. The level can be determined based on weight or visually. Alternatively, the fill level can also be determined using other types of sensors that are already known. If the filling of the hopper corresponds to the specified value and/or exceeds it, the sensor sends a corresponding signal to the control, which preferably triggers the start of pre-shredding by the control.

According to a further preferred embodiment, at least two sensors are provided, with a first sensor being provided for detecting an empty level of the funnel and a second sensor being provided for detecting a predetermined fill level, preferably a start-of-operation fill level, the control being set up to do so. Receive sensor signals from the first and second sensors. In addition to the above-mentioned determination of the fill level, an empty level of the funnel can also be detected, whereby when the empty level is reached, the control can preferably trigger an injection or re-injection of process water or the pumping can be stopped.

According to a further preferred embodiment, a further sensor is provided for detecting a liquid level in the product line, with the controller being set up to receive a sensor signal from the further sensor. In addition to the above-mentioned determination of the fill level, a liquid level in the product line can also be detected, whereby when a predetermined liquid level is reached or falls below, an injection or subsequent injection of process water can be stopped or triggered via the control or the pumping out can be stopped.

According to a further preferred embodiment, the control is set up to detect a torque and/or a rotational resistance of a drive driving the grinder and/or the pre-shredding unit, preferably an electric motor, wherein the control is preferably further set up to do so when the value falls below a predetermined limit a temporal change in the torque and/or the rotational resistance of the drive to switch on the pump. Furthermore, during the pre-shredding, a speed and/or a torque and/or a rotational resistance of a drive driving at least the pre-shredding unit are preferably determined at least in sections or intermittently, preferably continuously. In a continuation, a change over time of at least one of the determined values, preferably the change over time in the torque or rotational resistance, is compared with a predetermined limit value and/or preset value. The aforementioned temporal change can be used as a measure of the degree of homogenization of the Kitchen waste and/or food leftovers are used, whereby, if the change over time is less than the limit value and/or default value and/or is within a predetermined range, the mass resulting from the pre-shredding is sufficiently homogeneous so that effective pumping out by the pump and simultaneous shredding in the grinder is possible. This can be used as a trigger signal to start the pumping step. The control is preferably connected to at least one sensor for detecting the speed, the torque and/or the rotational resistance.

At least one of the sensors is preferably designed as an inductively measuring sensor, as a weight sensor or as an optical sensor.

According to a further preferred embodiment, a rotor of the grinder has at least one pump element on its underside, preferably in the form of a web, for introducing a movement impulse to a mass located below the grinder in the direction of the pump. As a result, an impulse can be transmitted to the kitchen waste and food leftovers homogenized by the grinder, which supports the conveying of the aforementioned mass in the direction of the pump.

Short description of the characters

Figur 1

schematisch eine perspektivische Seitenansicht einer Vorrichtung zum Zerkleinern von Küchenabfällen und/oder Speiseresten;

Figur 2

schematisch eine Schnittdarstellung der Vorrichtung aus Figur 1;

Figur 3

schematisch eine perspektivische Seitenansicht eines Mahlwerks der Vorrichtung aus Figur 1;

Figur 4

schematisch eine perspektivische Seitenansicht eines Details eines Rotors des Mahlwerks aus Figur 3;

Figur 5

schematisch eine Schnittansicht eines Trichters der Vorrichtung aus Figur 1 mit einem angedeuteten Mahlstrom; und

Figur 6

schematisch eine perspektivische Seitenansicht der Vorrichtung aus Figur 1 mit einem angedeuteten Mahlstrom.

Preferred further embodiments of the invention are explained in more detail by the following description of the figures. Show:

Figure 1

schematically a perspective side view of a device for shredding kitchen waste and/or leftover food;

Figure 2

schematically a sectional view of the device Figure 1 ;

Figure 3

schematically a perspective side view of a grinder of the device Figure 1 ;

Figure 4

schematically a perspective side view of a detail of a rotor of the grinder Figure 3 ;

Figure 5

schematically a sectional view of a funnel of the device Figure 1 with a hint of a maelstrom; and

Figure 6

schematically a perspective side view of the device Figure 1 with an implied maelstrom.

Detailed description of preferred embodiments

Preferred exemplary embodiments are described below with reference to the figures. The same, similar or identical elements in the different figures are given identical reference numbers, and a repeated description of these elements is partly omitted in order to avoid redundancies.

Figure 1 shows a perspective schematic representation of a device 1, which is used to shred kitchen waste and/or leftover food. The device 1 comprises a receiving device in the form of a funnel 2, which initially serves to receive the unshredded organic kitchen waste and food leftovers. The funnel 2 is in Figure 1 shown in the form of a funnel 2 with a rectangular cross section. However, other cross-sections can of course also be used, such as square cross-sections, round cross-sections or oval cross-sections. Furthermore, the funnel 2 can also have non-funnel-shaped sections, for example cylindrical sections.

At the lower end of the funnel 2 there is a grinder 3, to which organic kitchen waste and food waste are fed via the funnel 2. The grinder 3 is used to shred the organic kitchen waste and food leftovers fed via the funnel 2. The grinder 3 can, for example, in the in Figure 3 shown and described below.

A pre-shredding unit 4 is arranged on the grinder 3 and projects at least partially into the funnel 2 from the grinder 3. In other words, the pre-shredding unit 4 projects at least partially into the volume V defined by the dimensions of the funnel 2 (see also Figure 2 ) inside.

The pre-shredding unit 4 serves, on the one hand, for the improved feeding of kitchen waste and food scraps to the grinder 3. Feeding here means both the actual conveying of the organic kitchen waste and food scraps, for example by means of a screw conveyor, and also the making of the organic kitchen waste conveyable by pre-shredding or mechanical shaking in order to be able to feed light, loose, fibrous and/or dry kitchen waste and food scraps that were previously stuck in the funnel 2 to the grinder 3. The pre-shredding unit 4 therefore prepares the organic kitchen waste and/or moves it in such a way that it is fed to the grinder 3 or slides into it. The pre-shredding unit 4 can be provided with pre-shredding knives 46 in order to pre-shred the kitchen waste and leftover food.

The device 1 further comprises a lid 10, by means of which the funnel 2 can be covered. The funnel 2 must advantageously be covered with the lid 10 before the grinder 3 and the pre-shredding unit 4 are put into operation and begin to rotate. The lid 10 prevents the comminuted or to-be-comminuted mass from spraying out of the device 1 during operation. Furthermore, the lid 10 is there to prevent users from reaching into the funnel 2 when the grinder 3 and/or the pre-shredding unit 4 is being operated. The lid 10 is advantageously connected to a control, not shown in this view, which is equipped in such a way that the grinder 3 and the pre-shredding unit 4 can only be operated when the lid 10 is closed.

The control also has a schematically shown operating unit 80, by means of which a user can make inputs to the control and receive information from it.

A nozzle 14 for feeding process water into the funnel 2 is provided on a funnel wall 20 of the funnel 2 in order to be able to produce sufficient water content in dry organic kitchen waste to enable subsequent pumping out of the biomass shredded by the grinder 3. To pump out the moist and largely homogenized biomass that has been comminuted by the grinder 3, an appropriately sized pump 5 is provided after the grinder 3, for example in Figure 2 is shown.

The nozzle 14 can also be used to clean the funnel 2 as well as the grinder 3, the pre-shredding unit 4 and/or the lid 10. For cleaning or supplying process water, at least one further nozzle can also be provided at another location in the funnel 2 and/or in a product line described later.

Like, for example Figure 1 results, the pre-shredding unit 4 is arranged coaxially to the grinder 3, with the axis of rotation 400 of the pre-shredding unit 4 extending coaxially along the axis of rotation 300 of the grinder 3 or both axes of rotation 300, 400 coincide.

Figure 2 shows a schematic view of the device 1 in a schematic sectional view. In this figure it can be clearly seen that the pre-shredding unit 4 partially, although not completely, extends into the funnel 2 and in particular extends into the volume V formed inside the funnel 2. The volume V is defined here by the volume located between the lid 10, the funnel bottom 22 and the funnel walls 20 of the funnel 2.

The depth to which the pre-shredding unit 4 extends into the hopper 2 depends, among other things, on which organic kitchen waste and food leftovers are to be treated. Furthermore, the depth in this embodiment variant depends on how far the pre-shredding knives 46 of the driver 4 are from the funnel wall of the funnel 2. This distance D must be dimensioned so that even larger, light kitchen waste can still slip between the rapidly rotating pre-shredding knives 46 and the wall of the funnel 2, and in particular that a maelstrom, described in more detail later, can be generated in the funnel 2.

The grinder 3 arranged on the hopper bottom 22 is connected via a product line 7 to a pump 5 for pumping out the comminuted biomass via a transport line 15 into a tank 6 for receiving the pumped-out biomass.

The product line 7 has a water inlet 16 through which process water can be introduced into the product line 7.

The side funnel walls 20 have an angle of inclination α of 60° relative to the horizontal 13. In other words, the funnel wall and the direction of gravitational acceleration 12 form an angle β of 30°. The high inclination or gradient of the funnel wall 20 makes it possible for the solids and liquids or their suspension located in the funnel 1 to flow or move essentially independently towards the funnel bottom 22 due to gravity.

A magnetic element 9 is arranged on the funnel wall 20, by means of which ferromagnetic substances can be sorted out of the kitchen waste and/or food leftovers by applying a magnetic force.

Furthermore, a first sensor 81 for detecting an empty level of the funnel 2 and a second sensor 82 for detecting a predetermined start-of-operation filling level in the funnel 2 are arranged on the funnel wall 20. The sensors 81, 82 are optically measuring sensors. Alternatively, the fill level can also be determined via a weight sensor or at least one acceleration sensor, with the fill level being determined based on weight. The controller 8 is set up to receive sensor signals from the first and second sensors 81, 82.

In addition, the controller 8 is set up to detect a rotational resistance of a drive driving the grinder 3 and the pre-shredding unit 4. For this purpose, a sensor 84 for detecting the rotational resistance is arranged on the grinder 3.

A pump 5 is connected to the output of the grinder 3 via a product line 7. The pump 5 is set up to pump out shredded kitchen waste and leftover food into a tank 6 via the transport line 15. The shredded kitchen waste and food leftovers are preferably conveyed a certain distance in the transport line 15 by the pressure of the pump 5. The shredded kitchen waste and leftover food then flow further into tank 6 due to gravity.

Figure 3 shows the grinder 3 in a schematic perspective view. The grinder 3 comprises a rotor 30, which rotates about an axis of rotation 300 and is driven by a drive 32 in the form of an electric motor, to the motor shaft of which the rotor 30 is correspondingly connected. The drive 32 is advantageously provided with a strong brake, which immediately stops the cover 10 when the drive 3 is in operation.

The rotor 30 includes differently shaped drivers 34, which can carry the organic kitchen waste and food leftovers to be shredded and set them in rotation accordingly. A knife ring 36 is provided, which surrounds the rotor 30 and which serves as a stator. The organic kitchen waste and food leftovers set into a rotational movement by the rotor 30 are accordingly pressed against the knife ring 36 by centrifugal forces and guided along it in such a way that comminution takes place in the corresponding spaces between the knives. The drivers 34 in turn move along the knife ring 36, so that organic kitchen waste and food scraps extending through the spaces between the knives 36 can be sheared off by the driver 34. Other versions of the grinder 3 are also conceivable. The sensor 84 detects the speed, the torque and the rotational resistance of the drive 32.

Figure 4 a perspective side view of a detail of the rotor 30 of the grinder 3 can be seen schematically. The rotor 30 has on its underside 37 a plurality of pump elements in the form of webs 38 extending downwards from the underside 37, which are set up to introduce a movement impulse to a mass located below the grinder 3 in the direction of the pump 5. As a result, an impulse can be transmitted to the kitchen waste and food leftovers homogenized by means of the grinder 3, which supports the conveying of the aforementioned mass in the direction of the pump 5.

Below, a method for shredding kitchen waste and/or food leftovers, preferably for homogenizing kitchen waste and/or food leftovers, is described using the aforementioned device 1 as an example, and in the Figures 5 and 6 shown, which show a maelstrom 13 in the funnel 2, described in detail below.

In a first step, kitchen waste and food scraps to be shredded are placed in the funnel 2 and the lid 10 is then closed. After the lid 10 has been brought into the closed state, the controller 8 receives a corresponding signal and starts the processing cycle by the device 1.

First, a certain amount of process water is introduced into the product line 7 via the water inlet 16 provided in the product line 7. If the third sensor 83 detects that the product line 7 is filled with water to a certain level, the controller 8 receives a corresponding signal and stops introducing the process water into the product line 7. In addition, the controller 8 starts the drive 32. This will the rotor 30 and the pre-shredding unit 4 attached to it are set in rotation. By rotating the pre-shredding unit 4, it begins to shred or pre-shred the kitchen waste and food leftovers located in the hopper 2, essentially by the pre-shredding knives 46 cutting and smashing the kitchen waste and food leftovers.

Since the pump 5 is switched off, the kitchen waste and leftover food are not sucked out through the grinder 4, but remain in the funnel 2 and are further chopped there. By pre-shredding the kitchen waste and food leftovers, the cell structures of the organic waste are already largely destroyed in the funnel 2 to such an extent that the water contained in the kitchen waste and food leftovers is released in the funnel 2, which is thereby made usable before the kitchen waste and / or food leftovers are in the Grinder 3 can be shredded.

Due to the rotary movement of the pre-shredding unit 4, an aqueous suspension with a mushy consistency is formed in the funnel 2 from the shredded kitchen waste and leftover food and the water that has been knocked out. The kitchen waste and/or food scraps pre-shredded in this way make it easier to later chop them up by the grinder 3 if they are sucked out of the funnel 2 through the grinder 3 due to the insertion of the pump 5. In order to increase the water content of this suspension, process water can be added via the nozzle 14.

Due to the rotation of the pre-shredding unit 4, in addition to the shredding effect, energy is also transferred to the kitchen waste and food leftovers and these are set in rotation in the hopper 2. As a result, the pre-shredding unit 4 generates a circulating grinding stream 13 in the hopper 2. The kitchen waste and/or food leftovers in the hopper are consequently additionally stirred or mixed by the pre-shredding unit 4. This creates the maelstrom 13 in the hopper 2, which allows the material to circulate in the hopper 2 in both the horizontal and vertical directions. In the circulating maelstrom 13 generated by the pre-shredding unit 4, the kitchen waste and/or food leftovers rotate at different speeds depending on their position in the hopper 2. The closer kitchen waste and leftover food is to the pre-shredding unit 4, the higher its speed. As the distance to the pre-shredding unit 4 increases and the distance to the funnel wall 20 decreases, the speed decreases, with the particles being braked in particular by friction on the funnel walls 20 and among themselves. The parts or mass flows moving at different speeds and their friction with one another cause the kitchen waste and food leftovers to be further shredded in the maelstrom 13, which means that the kitchen waste and food leftovers are already in the hopper 2. As a result of the pre-shredding, a relatively homogeneous biomass is formed in the hopper 2, with the entire contents of the hopper 2 gradually being moved and comminuted by the grinding stream 13.

Figure 5 shows schematically a sectional view of the funnel 2. The maelstrom is indicated by the arrows numbered 13. The strength or thickness of the arrows is a measure of the speed. How Figure 5 To remove, the substances in the funnel 2 experience a strong acceleration in the direction of the funnel bottom 22 during pre-shredding in the area of the funnel center and are deflected outwards and upwards, whereby they are essentially slowed down due to the friction on the funnel wall 20 and among themselves. Once at the top, they are again caught by the suction of the pre-shredding unit 4 (not shown here) and accelerated downwards again. At the same time, the materials are further shredded.

Figure 6 shows schematically a perspective side view of the device 1. Again, the maelstrom is indicated by the arrows numbered with the reference number 13. The strength or thickness of the arrows is in turn a measure of the speed of the moving substances.

Like from the Figures 5 and 6 To remove, the pre-shredding unit 4 forms a grinding stream 13 in the hopper 2 in the horizontal and at the same time in the vertical direction.

Non-organic substances, such as textiles, plastic items such as films or gloves, are caught and wound up on the pre-shredding knives 46 during pre-shredding and are thus separated from the organic components.

Furthermore, ferromagnetic materials, such as knives or forks, are sorted out of the maelstrom 13 by applying a magnetic force using the magnetic element 9. The ferromagnetic substances remain stuck to the funnel wall 20 due to the magnetic force in the area of the magnetic element 9.

In order to increase the water content of the suspension from the pre-shredded kitchen waste and food leftovers, additional process water can be added via the nozzle 14.

The pre-shredding takes place for a period of time previously selected on the control unit 80 before the pump 5 is started and the pre-shredded kitchen waste and food leftovers are pumped out of the hopper 2 and thus the shredding by the grinder 3 is started.

After a predetermined period of pumping, the funnel 2 and the lid 10 are sprayed through the nozzle 14 using injected process water. This means that the process water is sprayed widely over the biomass still in the hopper and the lid and the hopper area are roughly cleaned.

During pumping out, the liquid level in the product line is recorded, and pumping out is stopped when the liquid level falls below a predetermined level.

A method for shredding kitchen waste and/or leftover food, preferably for homogenizing kitchen waste and/or leftover food, according to an alternative embodiment, is described below. The method according to the alternative embodiment essentially corresponds to the method described above, with the operating cycle having a higher degree of automation.

The pre-shredding is not started here when the lid 10 is closed, but only when the second sensor 82 also detects that a predetermined filling level has been reached. The second sensor 82 then transmits a corresponding signal to the controller 8, which then starts the pre-shredding 4.

The speed of the pre-shredding unit 4 is varied during the pre-shredding between a speed of 700 and 2800 revolutions per minute in order to achieve an improved mixing ratio and good comminution of different materials. In addition, the direction of rotation of the pre-shredding unit 4 is changed several times during pre-shredding.

Furthermore, the pre-shredding is not operated for a predetermined period of time, but begins when a change in the rotational resistance of the drive 32 determined by the sensor 84 and the controller 8 in a predetermined speed range is below a certain limit value or limit amount. The aforementioned change in time is used here as a measure of the degree of homogenization of the kitchen waste and/or leftover food, whereby, if the change in time is less than the limit value, the mass resulting from the pre-shredding is sufficiently homogeneous so that effective pumping is possible Pump and simultaneous grinding in the grinder is possible.

The injection of the process water for pre-cleaning is also triggered by a signal from the first sensor 81 when it detects a predetermined empty level in the funnel 2. After pumping has ended, process water is again fed through the nozzle 14 into the funnel 2 until the first sensor 81 detects that the water level is above the grinder 3. This prevents residues of shredded kitchen waste and leftover food from drying and becoming crusty in the grinder.

The present description also relates to a method for shredding kitchen waste and/or food leftovers, preferably for homogenizing kitchen waste and/or food leftovers, comprising the step of loading a hopper 2 for receiving kitchen waste and/or food leftovers, which is attached to a hopper bottom 22 with a grinder 3 for shredding, preferably homogenizing, the kitchen waste and / or food leftovers and is connected from the grinder 3 via a product line 7 to a pump 5 for pumping out shredded kitchen waste and / or food leftovers, with kitchen waste and / or food leftovers to be shredded, and the step of pumping out the kitchen waste and/or food leftovers shredded by the grinder 3 by means of the pump 5, ferromagnetic substances being extracted from the kitchen waste and/or food leftovers by applying a magnetic force at least in a region of a funnel wall 20 of the funnel 2, preferably at least be sorted out during pre-shredding.

The device 1 accordingly preferably has a magnetic device, by means of which the magnetic force is applied in at least one area of the funnel wall 20 of the funnel 2 can be. The magnetic device can be provided, for example, in the form of an electromagnet or a permanent magnet.

To the extent applicable, all individual features shown in the exemplary embodiments can be combined and/or exchanged with one another without departing from the scope of the invention.

Reference symbol list

1

contraption

2

funnel

20

funnel wall

22

funnel bottom

3

grinder

30

rotor

32

drive

34

taker

36

Knife wreath

37

bottom

38

web

300

Axis of rotation

4

Pre-shredding unit

46

Pre-shredding knife

400

Axis of rotation

5

pump

6

tank

7

Product management

8th

steering

80

Control unit

81

sensor

82

sensor

83

sensor

84

sensor

9

magnet

10

Lid

11

horizontal

12

direction of gravitational acceleration

13

Maelstrom

14

jet

15

Transport line

16

Water inlet

α

Angle of inclination

β

angle

Claims (15)

1. Method for grinding kitchen waste and/or food remnants, preferably for homogenising kitchen waste and/or food remnants, comprising the step of feeding a hopper (2) for receiving kitchen waste and/or food remnants, which is provided on a hopper base (22) with a grinder (3) for grinding, preferably homogenising, the kitchen waste and/or food remnants, and is connected from the grinder (3) via a product line (7) to a pump (5) for pumping out ground kitchen waste and/or food remnants, with kitchen waste and/or food remnants to be ground, and the step of pumping out the kitchen waste and/or food remnants ground by the grinder (3) by means of the pump (5),
   characterised in that
   before the step of pumping out, in the hopper (2), pre-grinding of the kitchen waste and/or food remnants located in the hopper (2) is performed by means of a pre-grinding unit (4) projecting into the hopper (2), wherein a homogenised mass is formed from the kitchen waste and/or food remnants in the hopper (2) during the step of pre-grinding, wherein the pump (5) is only switched on after the step of pre-grinding, in order to start pumping out.
2. Method according to claim 1, characterised in that during pre-grinding by the pre-grinding unit (4), a vortex (13) circulating in the hopper (2) is produced, wherein the pre-grinding unit (4) preferably produces the circulating vortex (13) in the hopper (2) by means of a rotational movement about an axis of rotation (400) of the pre-grinding unit (4).
3. Method according to any of the preceding claims, characterised in that before and/or during pre-grinding, a predetermined quantity of process water is introduced into the hopper (2) and/or into the product line (7), preferably via a nozzle (14) arranged in the hopper (2) and/or in the product line (7) and/or a water inlet (16).
4. Method according to any of the preceding claims, characterised in that during pre-grinding, a separation of inorganic materials takes place, preferably by entangling and/or winding the inorganic materials on at least one projection, preferably a pre-grinding blade (46), most preferably an at least partially blunt-edged pre-grinding blade (46), of the pre-grinding unit (4).
5. Method according to any of the preceding claims, characterised in that ferromagnetic materials are sorted from the kitchen waste and/or food remnants by applying a magnetic force at least in a region of a hopper wall (20) of the hopper (2), preferably at least during pre-grinding.
6. Method according to any of the preceding claims, characterised in that in a final phase of pumping out, the hopper (2) and/or a lid (10) covering the hopper (2) during operation is/are pre-cleaned by means of injected process water.
7. Method according to any of the preceding claims, characterised in that the pre-grinding unit (4) and/or the grinder (3) rotate at a speed of 700 to 2800 revolutions per minute, preferably at a speed of 1400 revolutions per minute, wherein the pre-grinding unit (4) and the grinder (3) preferably rotate synchronously.
8. Method according to any of the preceding claims, characterised in that the speed of the pre-grinding unit (4) and/or the grinder (3) is varied and/or the rotation of the pre-grinding unit (4) and/or the grinder (3) is interrupted and/or the direction of rotation of the pre-grinding unit (4) and/or the grinder (3) is reversed.
9. Method according to any of the preceding claims, characterised in that the method is at least partially automated, wherein preferably at least the start of pre-grinding and/or the end of pumping out take place automatically, wherein preferably a sensor signal triggers the start of pre-grinding and/or the start and/or the end of pumping out.
10. Device (1) for grinding of grinding of kitchen waste and/or food remnants, preferably for homogenising kitchen waste and/or food remnants, comprising a hopper (2) for receiving kitchen waste and/or food remnants, a grinder (3) arranged on a hopper base (22) of the hopper (2) for grinding, preferably homogenising, the kitchen waste and/or food remnants and a pump (5) connected to the grinder (3) via a product line (7) for pumping out ground kitchen waste and/or food remnants, wherein a pre-grinding unit (4) extending from the hopper base (22) into the inside of the hopper (2) for pre-grinding the kitchen waste and/or food remnants located in the hopper (2) is arranged in the hopper (2),
    characterised in that
    a controller (8) is provided, which is designed to control pre-grinding to form a homogenised mass from the kitchen waste and/or food remnants in the hopper (2) by means of the pre-grinding unit (4) and subsequent switching on of the pump (5) to pump out ground kitchen waste and/or food remnants.
11. Device (1) according to claim 10, characterised in that at least one sensor (81, 82, 83) is provided for detecting a fill-level in the hopper (2) and/or in the product line, wherein the controller (8) is designed to receive a sensor signal from the sensor.
12. Device (1) according to claim 10 or 11, characterised in that at least two sensors (81, 82) are provided, wherein a first sensor (81) is provided for detecting an empty state of the hopper (2) and a second sensor (82) is provided for detecting a predetermined fill-level, preferably a start of operation fill-level, wherein the controller (8) is designed to receive sensor signals from the first and second sensors (81, 82).
13. Device (1) according to claim 10 to 12, characterised in that a further sensor (83) is provided for detecting a liquid level in the product line, wherein the controller (8) is designed to receive a sensor signal from the further sensor (83).
14. Device (1) according to any of claims 10 to 13, characterised in that the controller (8) is designed to detect a torque and/or a rotational resistance of a drive (23) driving the grinder (3) and/or the pre-grinding unit (4), preferably of an electric motor, wherein the controller (8) is preferably further designed to switch on the pump (5) when the torque and/or the rotational resistance of the drive (32) falls below a predetermined threshold for a change over time.
15. Device (1) according to any of claims 10 to 14, characterised in that a rotor (30) of the grinder (3) has at least one pump element on its underside (37), preferably in the form of a rib (38), for introducing a movement impulse to a mass located below the grinder (3) in the direction of the pump (5).

Images