Agrigultural waste pre-treatment apparatus and method

Abstract

Apparatus (10) and method for pre-treatment of agricultural waste, wherein the apparatus (10) comprises: - a feeding group (11) for agricultural waste; - a treatment group (12) with a compartment (V) connected to the feeding group (11) to be supplied with agricultural waste; - an extraction group (13) for inert material, which has a channel (C) below the compartment (V) to collect inert material. The treatment group (12) comprises: -at least one shaft (123) that extends along the operational direction (A) and is rotatable around it; - reatment sections (S), each of which comprises first blades (124) and second blades (125), where the first blades (124) are configured to exert, following a rotation of the shaft (123) in a rotational direction, a thrust force in the opposite direction to a thrust force simultaneously exerted by the second blades (125). The treatment sections (S) are configured to exert an overall thrust (T) that pushes the contents of the compartment (V) towards the discharge section (122).

Description

[0001] AGRICULTURAL WASTE PRE-TREATMENT APPARATUS AND METHOD

[0002] DESCRIPTION

[0003] The present invention relates to an apparatus and method for the pre-treatment of agricultural waste, particularly for the removal of inert material and stones from poultry manure, slurry, and dung.

[0004] In general, in the field of processing waste derived predominantly from excrement such as poultry manure, slurry, and dung, the inventor of the present invention is aware of the need to feed such waste into a digester in a biologically optimal condition for the digestion phase.

[0005] The problem underlying the present invention is, therefore, to provide a pretreated agricultural waste material, particularly from poultry manure, slurry, and dung, in optimal conditions for an operational digestion phase, with the aim of overall optimization of the waste treatment process.

[0006] The primary objective of the present invention is to provide an apparatus and method for the pre-treatment of agricultural waste that allows for the production of an aqueous solution of such waste that is as homogeneous as possible.

[0007] Within this objective, a further aim of the present invention is to propose an apparatus and method for the pre-treatment of agricultural waste that enables the removal of inert or non-functional material for the digestion treatment process, such as, for instance, inert material contained in poultry manure and stones present in slurry and dung.

[0008] Another aim of the present invention is to provide an apparatus and method for the pre-treatment of agricultural waste that is structurally simple, easy to use and maintain, durable, and reliable. This aim, as well as the above-mentioned aims and others that will become clearer below, are achieved by an apparatus and method for the pre-treatment of agricultural waste according to the attached independent claims.

[0009] Detailed features of an apparatus and method for the pre-treatment of agricultural waste according to the invention are provided in the dependent claims, which are hereby incorporated by reference.

[0010] Further features and advantages of the invention will emerge more clearly from the description of a preferred, though not exclusive, embodiment of an apparatus and method for the pre-treatment of agricultural waste according to the invention, provided by way of example and not limitation in the accompanying drawings, in which:

[0011] - Figure 1 illustrates a simplified schematic top view of an agricultural waste pre-treatment apparatus according to the present invention;

[0012] - Figure 2 illustrates a simplified schematic side sectional view of an agricultural waste pre-treatment apparatus according to the present invention;

[0013] - Figure 3 illustrates a simplified schematic side sectional view of a detail of an agricultural waste pre-treatment apparatus according to the present invention, showing a variant of the apparatus depicted in Figures 1 and 2.

[0014] With particular reference to the cited figures, the agricultural waste pretreatment apparatus is generally indicated as 10, and it comprises:

[0015] - a feeding unit 11 for supplying agricultural waste;

[0016] - a treatment unit 12, which defines within it a compartment V designed to contain a solution, which may be aqueous, of agricultural waste. This unit is connected to the feeding unit 11 to receive agricultural waste;

[0017] - an extraction unit 13 configured to remove inert material. It features a channel C located beneath the compartment V to collect inert material that settles by gravity during the operation of the treatment unit 12.

[0018] The treatment unit 12 can extend along an operational direction A within the compartment V and includes a loading section 121 and a discharge section 122, positioned at opposite ends along the operational direction A.

[0019] The treatment unit 12 can be configured such that, under operating conditions, the operational direction A is substantially horizontal. It may have a slope that is preferably zero or falls within a range of approximately +20° to -20° relative to a horizontal direction.

[0020] The loading section 121 can be connected to the feeding unit 11 to be supplied with material to be processed, such as agricultural waste, poultry manure, and / or dung and / or slurry mixed with insoluble inert material, such as stones and / or calcifications.

[0021] The feeding unit 11 may include, for example, a hopper 111 and a screw conveyor 112, which could feature a single screw or a pair of screws — optionally counter-rotating — or a belt conveyor connected to the hopper 111 to receive material for feeding into the treatment unit 12.

[0022] The hopper 111 can be equipped with mixing and feeding screws to push the material into the screw conveyor 112.

[0023] The treatment unit 12 may include: at least one shaft 123 that extends along the operational direction A and is rotatable around it; treatment sections S, each comprising first blades 124 and second blades 125 that can extend outwardly from the shaft 123.

[0024] The first blades 124 may be configured to exert, as a result of the rotation of the shaft 123 in an operational direction V, or rotational direction, a thrust force in the opposite direction to the thrust force simultaneously exerted by the second blades 125.

[0025] For example, the first blades 124 and the second blades 125 may have opposing inclinations with respect to a plane transverse to the operational direction A, as shown, for instance, in Figure 2.

[0026] In other words, for example, the first blades 124 can have a first inclination with respect to a plane transverse to the operational direction A to exert a first force on the contents of the compartment V. For instance, the first blades 124 can be configured to form a first angle, such as an angle between 20° and 60°, preferably between 30° and 45°, with said plane transverse to the operational direction A.

[0027] According to this aspect, the second blades 125 can have a second inclination with respect to the plane transverse to the operational direction A to exert a second force on the contents of the compartment V, preferably such that the second inclination is opposite to the first inclination of the first blades 124. For example, the second blades 125 can be configured to form a second angle, such as an angle between 120° and 160°, preferably between 135° and 150°, with said plane transverse to the operational direction A.

[0028] In this way, the first blades 124 are configured to exert, as a result of the rotation of the shaft 123 in an operational direction V, or rotational direction, a first thrust force on the contents of the compartment V, where this first thrust force is directed along a first direction. Similarly, the second blades 125 are configured to exert, as a result of the rotation of the shaft 123 in the operational direction V, or rotational direction, a second thrust force on the contents of the compartment V in the loading section 121 , where this second thrust force is directed along a second direction opposite to the first direction.

[0029] Put differently, the first blades 124 are configured to exert a first force in a first direction, while the second blades 125 are configured to exert a second force in a second direction, where the second direction is opposite to the first direction.

[0030] The first blades 124 and the second blades 125 are arranged and configured such that the overall force, which is the force resulting from the combination of the first thrust force, or the thrust force of the first blades 124, and the second thrust force, or the thrust force of the second blades 125, is configured to push the contents of the compartment V from the loading section 121 to the discharge section 122.

[0031] Thus, in general, a mixing motion M can be achieved at the treatment sections S, leading to widespread and effective homogenization of the material treated by the apparatus 10, while also enabling effective separation of the inert materials that tend to easily settle to the bottom of the compartment V, separating them from the material in which they were embedded.

[0032] The treatment sections S can be configured to exert an overall force that pushes the contents of the compartment V, including both the liquid solution and any inert materials that settle, from the loading section 121 to the discharge section 122.

[0033] This overall force T is given by the combination of the thrust force of the first blades 124 and the thrust force of the second blades 125.

[0034] Preferably, the treatment group 12 is configured such that the compartment V is filled to about 3 / 4 of its height, for example, at the level L of figure 2, with an aqueous solution of the material to be treated fed into the compartment V by the feeding group 11.

[0035] The apparatus 10 may have at least one inlet for introducing water into the compartment V, not shown, or water may be introduced into the compartment V via the feeding group 11 .

[0036] In particular, the apparatus 10 may have a plurality of water injectors, distributed along the length of the compartment V and connected to a water source, preferably designed to supply them with pressurized water, in order to enhance the mixing effect of the material within the compartment V.

[0037] As shown in figure 2, the first blades 124 and the second blades 125 may have different radial extensions relative to the shaft 123, in order to exert different thrust forces on the material contained in the compartment V of the treatment group 12.

[0038] In an alternative embodiment of the invention, not shown in the attached figures, the first blades 124 and the second blades 125 could have the same extension relative to the shaft 123 and a different inclination, still providing a different thrust on the material contained in the compartment V of the treatment group 12, in order to cause the material to move from the loading section 121 to the discharge section 122.

[0039] In general, to achieve optimal mixing, the first blades 124 and / or the second blades 125 may have an end that brushes against an internal surface of the compartment V, which is preferably cylindrical.

[0040] The channel C of the extraction group 13 may extend downward and, for example, substantially parallel to the compartment V, which is tapered in such a way as to promote the collection of inert material by gravity into the channel C.

[0041] In alternative embodiments of the present invention, not illustrated in the attached figures, the channel C may form a downward slope from the compartment V.

[0042] The extraction group 13 may extend along the entire length of the treatment group 12 or, as shown in figure 2, only part of the length of the treatment group 12, depending on the specific implementation requirements of the invention.

[0043] The compartment V and the channel C re in communication through a discharge opening 126 that allows the inert material that has settled to the bottom of the compartment V to enter the channel C.

[0044] The discharge opening 126 may extend over only a portion of the length of the channel C and / or the compartment V, as shown in figure 2, or it may extend substantially along the entire length of the channel C, so that the channel C is fully open towards the compartment V.

[0045] The extension of the extraction group 13 relative to the treatment group 12 and the extension of the discharge opening 126 relative to the length of the compartment V depend on the specific implementation requirements of the present invention.

[0046] The apparatus 10 may include an expulsion device 14 designed to remove material that collects in the channel C of the extraction group 13 during the operation of the apparatus 10.

[0047] The expulsion device 14 may optionally include:

[0048] - at least one first screw conveyor 141 operable to push the material collected in the channel of the extraction group towards a discharge opening of the latter; at least one belt with a scraper operable to push the material collected in the channel of the extraction group towards a discharge opening of the latter.

[0049] The apparatus 10 may also include a removal group 15 with one end connected to the extraction group 13 to receive material from it and transfer it to a collection station, which may include, for example, a collection hopper, known in itself and not illustrated in the attached figures.

[0050] The removal group 15 may be configured to extend upwards, for example, at an inclination between 30° and 75° relative to the horizontal plane, and preferably between 45° and 60°, in such a way that the upper section 151 exceeds in height the solution level L that - in use conditions - is contained in the treatment group 12.

[0051] The upper section 151 preferably includes washing means designed to wash the material that passes through the upper section 151 .

[0052] For example, the washing means may include nozzles 152 designed to spray pressurized water to wash the inert materials removed from the material treated in the treatment group.

[0053] Thus, for example, in the case of treating slurry, manure, and / or poultry litter, the removal group 15 allows the discharge of gravel that is already cleaned of residues from the treated material.

[0054] The treatment group 12 may include a plurality of fixed blades, not illustrated in the attached figures, which project internally into the compartment V, preferably along a helical trajectory extending around the operational direction A.

[0055] The presence of such fixed blades, combined with the action of the first blades 124 and second blades 125, helps to promote the advancement of material from the inlet section to the outlet section of the treatment group 12 as the shaft 123 rotates in the operational direction V, or rotation direction.

[0056] As mentioned earlier, the treatment group 12 and the extraction group 13 can extend over different lengths along the operational direction A, as exemplified in figure 2, where the extraction group is positioned so that the discharge opening of the compartment V into the channel C is in a substantially central position of the compartment V.

[0057] In this case, for example, the length of the treatment group 12 may be greater than the length of the extraction group 13.

[0058] The extraction group 13 may extend from a terminal 12a of the treatment group 12 towards the discharge section 122.

[0059] Preferably, the treatment group 12 and the extraction group 13 are configured to move material inside them in opposite directions.

[0060] In other words, the treatment group 12 and the extraction group 13 may operate in a counter-current configuration so that the extraction group 13 pushes the inert materials collected in it in the opposite direction to that in which the treatment group 12 pushes the solution being treated towards the discharge section 122.

[0061] This presents a significant advantage in terms of compactness of the system, with the discharge of inert materials in a position and direction opposite to that of the discharge of the treated material, through the discharge section 122.

[0062] The removal group 15 may optionally include: at least one second screw conveyor 153 operable to push material received from the extraction group 13 towards and, preferably, through the upper section 151 ; at least one belt with at least one scraper operable to push material received from the extraction group 13 towards and, preferably, through the upper section 151 .

[0063] With particular reference to figure 3, an apparatus 10 according to the present disclosure may include a mixing group 16 housed in the compartment V and extending along the operational direction A.

[0064] The mixing group 16 may include:

[0065] - a plurality of annular supports 161 connected to a cylindrical internal part of the treatment group 12 in a rotatable manner around the operational axis A;

[0066] - third blades 162 that are fixed sequentially to each annular support 161 so as to project into the compartment V, preferably towards the shaft 123 and, more preferably, towards the first blades 124 and / or the second blades 125.

[0067] The mixing group 16 may also include fourth blades 163, where the third blades 162 are fixed to the first annular supports 161 and the second blades are fixed to the second annular supports 161 in such a way that the first annular supports are each alternated with one of the second annular supports 161 , along the operational direction A.

[0068] The third blades 162 may extend towards the first blades 124, and the fourth blades 163 may extend towards the second blades 125.

[0069] Preferably, the third blades 162 are inclined opposite to the first blades 124, and the fourth blades 163 are inclined opposite to the second blades 125, as shown in figure 3 for example, with dashed lines, where the orientation of the third and fourth blades 162 and 163 is shown in dashed lines according to the view plane x-x.

[0070] The annular supports 161 may be connected to drive means designed to rotate them around the operational axis A.

[0071] These drive means may be capable or operable to rotate the annular supports 161 in a direction opposite to that of the rotation of the shaft 123.

[0072] Also forming the subject of the present invention is a method for pre-treating agricultural waste, particularly poultry manure, slurry, and / or dung, which includes:

[0073] - a phase A, in which a liquid solution of agricultural waste material is introduced into a pre-treatment apparatus for agricultural waste through a feeding group 11 of the apparatus and mixed in a compartment V of the treatment group 12 of the apparatus through first blades 124 and second blades 125 of the shaft of the treatment group 12 to homogenize it and cause a gravity fall of inert material towards the bottom of the compartment V;

[0074] - a phase B of collecting and removing the inert material that during phase A has fallen by gravity, which may be carried out, for example, by an extraction group 13.

[0075] Phase A may involve the formation of a plurality of vortex motion zones M that follow each other along the extension of the compartment V, which have an overall movement force T such that the solution is pushed from a loading section 121 to a discharge section 122, from which the waste material is fed and discharged from the compartment V.

[0076] For example, phase A may be carried out by the treatment group 12. This method preferably includes a phase C, following phase B, which involves washing the inert material extracted from the compartment V, which may be carried out, for example, by a removal group 15 and especially, for example, by washing with nozzles 152 of the upper sector 151 .

[0077] It is understood, therefore, that the invention solves the stated problem and achieves the mentioned tasks and objectives.

[0078] In particular, an apparatus and method for pre-treatment of agricultural waste, according to the present invention, allows for effective mixing and homogenization of agricultural waste typically comprising poultry manure, slurry, and / or dung mixed with water-insoluble or inert materials such as stones. Furthermore, an apparatus and method for pre-treatment of agricultural waste according to the present invention allows for the inert material typically contained in the agricultural waste to be washed of contaminating residues, for example, directly obtaining washed stones and / or gravel from the treatment of slurry and / or dung.

[0079] The invention as conceived is susceptible to numerous modifications and variations, all within the scope of protection of the attached claims. Furthermore, all details can be replaced with other technically equivalent elements.

[0080] In practice, the materials used, as well as the contingent shapes and sizes, may be varied depending on the specific needs and the state of the art. Where the constructional characteristics and techniques mentioned in the following claims are followed by reference signs or numbers, these signs or reference numbers have been added solely to increase the intelligibility of the claims and, consequently, they do not constitute in any way a limitation on the interpretation of each element identified, purely as an example, by such signs or reference numbers.

Claims

CLAIMS1 . Agricultural waste pre-treatment apparatus which includes:- a feeding unit (11 ) of agricultural waste;- a treatment unit (12) defining a compartment (V) suitable for accommodating a solution of the agricultural waste, connected to the feeding unit (11 ) to be fed by agricultural waste;- an extraction unit (13) of inert material, which has a channel (C) located below the compartment (V) to collect inert material which, during the operation of the treatment unit (12), falls due to gravity; where the treatment unit (12) develops along an operating direction (A) and has a loading section (121 ) and an unloading section (122) which are located in distal positions along the operating direction (A); the loading section (121 ) is connected to the feeding unit (11) to be fed by agricultural waste; where the treatment unit (12) comprises:- at least one shaft (123) which extends along the operating direction (A) and is rotatable around it;- treatment sections (S) each of which includes first blades (124) and second blades (125) wherein the first blades (124) are configured to exercise, following a rotation of the shaft (123) in a rotational direction, a first thrust stress along a first direction, on a content of the compartment (V), and wherein, simultaneously, the second blades (124) are configured to exercise, following a rotation of the shaft (123) in the rotational direction, a second thrust stress, along a second direction, on a content of the compartment (V), wherein said second direction is opposite to the first direction; wherein the treatment sections (S) are configured so as to exert an overall stress that pushes a content of thecompartment (V) from the loading section (121 ) towards the unloading section (122), where this overall stress is given by the combination of the thrust stress of the first blades (124) and the thrust stress of the second blades (125).

2. Agricultural waste pre-treatment apparatus according to claim 1 wherein the first blades (124) and the second blades (125) have a different radial extension with respect to the shaft (123) to exert the different thrust stresses.

3. Agricultural waste pre-treatment apparatus according to claim 1 or 2, wherein the first blades (124) are configured to form a first angle with a plane transverse to said operational direction (A) to exert said first thrust force, and wherein the second blades (125) are configured to form a second angle with a plane transverse to said operational direction (A) to exert said second thrust force.

4. Agricultural waste pre- treatment apparatus according to the preceding claim, wherein said first angle is an angle comprised between 20° and 60°, and wherein said second angle is comprised between 120° and 160°.

5. Agricultural waste pre-treatment apparatus according to one of the previous claims wherein the channel (C) of the extraction unit (13) extends below and substantially parallel to the compartment (V), the latter being flared in such a way as to promote a collection by falling of the inert material into the channel (C).

6. Agricultural waste pre-treatment apparatus according to one of the previous claims which comprises an ejection device (14) suitable for removing material that is collected in the extraction group during the operation of said pretreatment apparatus; wherein said ejection device (14) comprises a choicebetween:- at least a first auger 141 that can be operated to push material collected in the channel of the extraction unit towards a discharge mouth of the latter;- at least one belt equipped with at least one scraper that can be operated to push material collected in the channel of the extraction unit towards a discharge mouth of the latter.

7. Agricultural waste pre-treatment apparatus according to any of the preceding claims, wherein said compartment (V) is cylindrical and has an internal surface which is skimmed by one end of the first blades (124) and / or by one end of the second blades (125).

8. Agricultural waste pre-treatment apparatus according to any of the preceding claims, wherein said treatment unit (12) comprises a plurality of fixed blades which project internally from said compartment (V) preferably along a helical trajectory around said operating direction (A) to promote an advancement of material from the loading section to the unloading section of the treatment unit (12) following the rotation of the shaft (123) in the rotational direction.

9. Agricultural waste pre-treatment apparatus according to any of the preceding claims, wherein said treatment unit (12) and said extraction unit (13) extend for different lengths along the operating direction (A); the length of the treatment unit (12) being greater than the length of the extraction unit (13) and the extraction unit (13) extending from a terminal of the treatment unit (12) towards the unloading section (122).

10. Agricultural waste pre-treatment apparatus according to any of the preceding claims, comprising a removal unit (15) having one end connected tothe extraction unit (13) to receive material from the latter and transfer it to a collection station; said removal unit (15) is configured to extend upwards, in working conditions, so as to have an upper sector (151 ) which exceeds in height the level of solution which - under conditions of use - is contained in the treatment unit (12).11 Agricultural waste pre-treatment apparatus according to the previous claim wherein the upper sector (151 ) includes washing means suitable for washing material passing through the upper sector (151 ).

12. Agricultural waste pre-treatment apparatus according to one of claims 10 and 11 wherein said removal unit (15) comprises a choice between:- at least one auger operable to push material coming from the extraction unit (13) towards and, preferably through, the upper sector (151 );- at least one belt equipped with at least one scraper operable to push material received from the extraction group (13) towards and, preferably through, the upper sector (151 ).

13. Method of pre-treatment of agricultural waste which provides for:- a phase A, in which a liquid solution of agricultural waste material is introduced into a pre-treatment apparatus for agricultural waste through a feeding unit (11 ) of the apparatus itself and is stirred in a compartment (V) of a treatment unit (12) of said apparatus by means of first blades (124) and second blades (125) of a shaft (123) of said treatment unit (12) to homogenize it and to cause the inert material to fall by gravity towards the bottom of the compartment (V);- a phase B of collection and removal of the inert material which fell due to gravity during phase A.

14. Method according to claim 13 wherein phase A provides for the formation of a plurality of zones of vortex motion which follow one another along said compartment (V) and which present a resulting movement component such that the solution is pushed from a loading section (121 ) to an unloading section (122) from which the waste material is respectively fed and discharged from the compartment (V).

15. Method according to one of claims 13 and 14 which comprises a phase C, following phase B, which provides for a washing the inert material extracted from said compartment (V).Pre-treatment apparatusFeeding group (11 )Treatment group (12)Compartment (V) VLoading section (121 )Discharge section (122)Shaft (123)Treatment sections (S)Solution SExtraction group (13)Operational direction (A)First blades (124)Second blades (125)Discharge opening (126)Operational direction (V) VOverall stress RHopper (111 )Fixed bladesRemoval group (15)Upper section (151 )

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