EP2818253A1

EP2818253A1 - Separation unit for fibrous materials and pneumatic bedding material conveying plant comprising such a unit

Info

Publication number: EP2818253A1
Application number: EP14173639.7A
Authority: EP
Inventors: Fabio Franco
Original assignee: IWT Srl
Current assignee: IWT Srl
Priority date: 2013-06-25
Filing date: 2014-06-24
Publication date: 2014-12-31
Also published as: ITMI20131057A1

Abstract

A separation unit of fibrous materials, in particular of fibrous materials contained in bedding for animals, to be associated to a bedding-air separation module of a pneumatic bedding conveying plant, comprising:
- a first interface (11a) associable to a first outlet duct (100, 110) of the bedding-air separation module;
- a second interface (12a) associable to a second suction duct (150, 160) of the bedding-air separation module;
- filtering means (9, 10) being interposed between said first interface (11a) and said second interface (12a) and being configured to trap fibrous materials contained in said bedding material. Furthermore, a pneumatic bedding conveying plant comprising a separation unit (1) according to the present invention is described.

Description

PRIOR ART

As known, in the sector of animal facilities for pharmaceutical research, the animals are kept in specific containment trays. Such trays constitute, in practice, the environment in which such animals live, and must therefore be as comfortable as possible, in addition to complying with hygienic requirements. Typically, each tray comprises: a bowl, adapted to contain the animals; a lid for closing the bowl and a trough for housing feed and/or other various accessories.
A bedding is added on the bottom of the bowl to at least partially absorb the animals' excrements.
In general, such a bedding comprises wood shavings or other similar material capable of absorbing and retaining humidity.
The animals kept in the bowls therefore rest on the bedding, and move and perform their normal vital activities on it. In order to improve animal comfort, the bedding has been modified by adding soft consistency fibrous material to the wood shavings, which is known in the sector as "ENRICHMENT".
This "ENRICHMENT" may consist of: cotton balls, cellulose strips, vegetable or artificial hay, wood shavings and filaments of various nature, vegetable leafs and, in general, agglomerates which create well-being conditions for the animal. Besides adding "ENRICHMENTS", the recent market trend is to suggest different types of bedding and bedding obtained from cellulose, again with the objective of improving excrement absorption and creating a more comfortable environment. For all the described bedding solutions, a sheet of blotting paper on which the bedding is deposited, in turn, may be provided on the bottom of the bowl.
As mentioned, the bedding allows to collect, and in part absorb, the animals' excrements, and thus must be periodically changed. Lack of care or an insufficient changing frequency may cause diseases in the animals, altering their vital parameters, and consequently distorting the measurements being monitored of interest for the research which is being carried out.
The changing of the soiled bedding contained in a tray requires to empty the tray into an unloading hopper, to shred the bedding to reduce its size and to suck it into specific collection containers to be finally disposed of as waste. The bedding is conveyed from the unloading hopper to the collection container by means of a pneumatic conveying plant, and therefore a vacuum pump connected to a specific sucking duct is provided.
The collection container integrates a bedding-air separation module for separating the bedding material from the suction air by means of the vacuum pump. Additionally, a main filtering assembly is provided between the separation module and the sucking duct to prevent portions of bedding material which were not separated during the previous strep from coming into contact with the pump and being scattered into the environment. Furthermore, to reduce the scattering of bedding as much as possible, a HEPA filter may be provided after the filtering unit to abate possible residual dust preventing it from being scattered into the external environment as much as possible.
As known in the prior art, a first separation module requires the soiled bedding to be sucked and conveyed into a collection container to be later disposed of as waste.
Such a container is, in general, a closed volume made by means of metal sheet walls, two ducts being provided in one of these walls: the first duct is connected to the soiled bedding unloading hopper, the second duct is connected to the vacuum pump to suck up the soiled bedding within the containment. A main filtering assembly is provided for the aforesaid reasons between the second duct and the vacuum pump, thus externally to the container.
Alternatively, such plants include the use of a cyclone for separating the bedding. The sucking of the bedding by means of vacuum pump and the separation of the bedding material contained in the sucked air by means of the cyclone is thus provided.
Such solutions are certainly effective for bedding constituted by wood shavings only or other similar material, in which case the specific weight of such material allows it to fall onto the bottom of the collection container or of the cylindrical collection portion of the cyclone and to be effectively separated from the sucked air, the separation of the materials sucked by the vacuum into the cyclones or into the containers being based no the loss of speed of the material, which by effect of its specific weight and gravity tends to fall downwards and accumulate on the bottom of the collection containers.
Instead, such separation modules may be ineffective for bedding comprising fibrous materials. Indeed, the added fibrous materials have a very low specific weight, and therefore they tend not to fall onto the bottom of the collection container or of the cylindrical collection portion of the cyclone but to follow the sucked air path and end up in the main filtering assembly, and possibly on the HEPA filter. Such a solution thus leads to a rapid clogging up of the filtering assembly of the traditional type.
Furthermore, the new materials used for the bedding are, as mentioned, materials having fibrous nature, which tend to bind and compact on the surface of the filtering cartridges, making the later cleaning of the main filter of known type impossible. In order to remove such materials, the usual cleaning method, which consists in blowing a jet of pressurized air onto the filtering assembly from the side opposite to the oneon which the dust accumulates to clear the assembly itself, is not sufficient; instead, a more detailed cleaning is needed, which requires to stop the entire plant, with obvious difficulties and lack of productivity that this implies.

SUMMARY

Consequently, the prior art described in part does not allow to have a pneumatic bedding conveying plant which guarantees good performance and reliability of use without frequent maintenance operations.
The ever increasing attention to the conditions in which animals are kept in animal facilities leads to an increasingly common use of bedding with the addition of fibrous material.
In combination with this, above all in laboratories with numerous trays, the amount of soiled bedding which must be eliminated every day is rather high: it is such to clog up the filtering assembly in a short time and a frequent, detailed maintenance of the same is necessary. As mentioned, this operation requires to stop the plant, and this greatly limits plant efficiency as a result of the consequently long downtimes.
It is the main object of the present invention to make a separation unit for fibrous materials to be applied to separation modules for pneumatic bedding conveying plants which allows to solve the problems illustrated above in simple and cost-effective manner.
In the scope of this first task, it is a first specific object to make a separation unit which allows to trap the fibrous material preventing it from being conveyed to the filtering assembly.
A second specific object is to improve the efficiency of the filtering assembly of the traditional type and to reduce the complexity of the cleaning operations needed to restore its functionality.
A third specific object is to provide a separation unit which may be installed on existing bedding conveying plants and be adapted to the respective different separation modules with which said plants are equipped.
It is thus the object of the present invention to supply a new, original separation unit intended to be mounted on a bedding conveying plant between a first and second duct present on the separation module of the aforesaid plant to trap possibly contained fibrous materials at the outlet of the separation module.
These and other objects and advantages, which will be more apparent from the following detailed description of a preferred embodiment of the present invention, are reached by means of a separation device for fibrous materials according to claim 1.

LIST OF FIGURES

The technical features of the present invention and its advantages will be apparent from the following description, which must be considered in combination with the accompanying drawings, in which:

figure 1 is a perspective view of a first embodiment of a separation unit for fibrous materials according to the present invention;
figure 2 is a further perspective view of the separation unit for fibrous materials in figure 1, in which some components of the separation device areviewable in particular;
figure 3 shows a top view of the separation device according to the present invention;
figure 4 is a perspective view of the separation unit in figure 1 during a step of maintenance;
figure 5 shows a detail of a filtering assembly of the traditional type on which a separation unit according to a second embodiment of the present invention is mounted;
figure 6 shows a detail of figure 5;
figure 7 shows a detail in side view of figure 6.

DETAILED DESCRIPTION

The following description and the respective drawings are provided only by way of example of the present invention which may be implemented according to other, different embodiments; furthermore, it must be considered that such figures are diagrammatic and simplified.
The object of the present invention is designed to be installed in pneumatic bedding conveying plants, for example used in animal facilities.
Such plants convey the bedding by exploiting air, e.g. conveying it in specific ducts by means of a vacuum pump. These plants are thus provided with bedding-air separation modules for separating the bedding from the air used for conveying. The figures 1 to the 5, described in detail below, refer to a first embodiment of a unit 1 according to the present invention. In particular, such a unit is designed to be installed on bedding conveying plants provided with cyclone bedding-air separation module.
Figures 6 to the 8, described in detail below, refer to a second different embodiment of a unit 1 according to the present invention. Such a unit is designed to be installed on bedding conveying plants provided with container bedding-air separation module.
Despite the different application destinations, the different embodiments remain within the same inventive idea, and thus provide a single technical teaching.
Figure 1 shows the first embodiment of a separation unit of fibrous materials, in particular fibrous materials contained in bedding for animals, intended to be mounted on a bedding-air separation module of a pneumatic conveying plant of the aforesaid bedding and comprising:

a first interface 11 applied at a first duct 100 of the bedding-air separation module (of the cyclone type, in this case);
a second interface 12 applied at a second duct 150 of the bedding-air separation module;
filtering means 9 interposed between said first interface 11 and said second interface 12, configured to trap fibrous materials contained in the material bedding. As mentioned, the unit 1 in the figure is configured to be applied to a cyclone bedding-air separation module (not shown in figures). In particular, it is set in series, i.e. connected in succession, to the latter. For this purpose, the filtering means 9 of the unit 1 comprise a separation body 13 provided with a fluid inlet 11a and a fluid outlet 12a (which are the first interface 11 and the second interface 12). The inlet 11a connects to the outlet duct 100 of the cyclone separation module, while the outlet 12a connects to the duct 150, which joins the cyclone separation module to the sucking duct of said pneumatic conveying plant. It is worth noting that, for application solutions of cyclone separation modules, the first duct and the second duct typically coincide; indeed, the sucking mouth of the conveying plant (connected to the vacuum pump) is connected directly to the cyclone module outlet.

Thus, the separation unit according to this first embodiment connects to the outlet 100 of the cyclone module, by means of the inlet 11a and is connected, in turn, by means of the outlet 12a, to the sucking mouth 150 of the conveying plant.
As mentioned, the separation body 13 is set in series with the cyclone module, and thus receives in input an air flow already separated from larger size bedding portions but containing possible fibrous material to be trapped. For this purpose, the body 13 is also designed to exploit the principle underlying separation by cyclone, by integrating specific means capable of trapping the fibrous materials conveyed by the corresponding air flow from the cyclone module outlet.
Figure 2 shows a preferred embodiment of a separation body 13. It comprises, in succession:

an upper portion 14 comprising the aforesaid outlet 12a which may be connected, in use, to the sucking duct 150 of the pneumatic conveying plant;
a central portion 15 connected to the upper portion 14 and comprising the fluid inlet 11a which may be connected, in use, to the outlet 100 of the cyclone bedding-air separation module;
a filtering grid 18, applied within either the upper portion 14 or the central portion 15;
a lower portion 16 connected to the central portion and adapted to collect the fibrous material trapped by the filtering grid 18.

Preferably, the upper portion 14 is truncated cone shaped, the cross section of which increases in direction of the central portion 15 to which it is connected on the bottom, and integrates the fluid outlet 12a on the upper end.
The central portion 15 is preferably cylinder shaped, the diameter of which corresponds to the diameter of the base of the truncated cone of the upper portion 14. In particular, the central portion 15 connects to the upper portion 14 at the upper junction area 15a.
The lower portion 16 is also truncated cone shaped and connects to the cylinder 15 at the lower junction area 15b of the latter (opposite with respect to the upper junction area 15a). The cross section of the truncated cone which composes the lower portion 16 reduces in direction opposite to the upper part 16, i.e. decreases from the lower junction area 15b downwards.
As shown again in figure 2, a collection vessel 17,in which the fibrous material trapped by the grid 18 is deposited, is connected to the lower portion 16. The vessel 17 is reversibly connected to the lower portion 16 so as to be periodically emptied. Furthermore, it is worth noting that is fixed in sealed manner to the aforesaid lower portion 16 to avoid air leakage and to ensure good sucking efficiency as a consequence. For this purpose, sealing means may be provided at the junction area 17a: for example a rubber lip on the edge of the vessel 17 to obtain fluid tightness, and hinges for fastening vessel 17 and lower portion 16. The aforesaid conformation of the body 13 thus allows to receive the air flow from the separation cyclone by means of the inlet 11a following the suction of the vacuum pump connected to the body 13 itself by means of the outlet 12a. In particular, the inlet 11a is integrated in a tangential portion of the outer surface of the central portion 15. Thus, the input air flow containing the fibrous material travels upwards along a stretch (for example, traveling along the inner wall of the central containment portion 15), i.e. towards the upper junction area 15a, goes beyond the grid 18 and exits through the outlet 12a. The fibrous material is captured by the grid 18 in this manner.
Figure 3 shows an embodiment of the grid 18 according to the present invention. To effectively capture the fibrous material, such a grid has an appropriately shaped weave, preferably made of perforated metallic mesh or other filtering material of appropriate shape, to trap the filament-like components of the material and let through the air flow, which is separated from the material itself in this manner. Preferably, the grid 18 is applied within the separation body 13 at the upper junction area 15a, thus has a cross section substantially coinciding with the diameter of the central portion 15, so as to avoid the undesired passages of air which was not appropriately filtered.
Furthermore, the grid 18 may comprise sensor means (not shown in the figures) adapted to detect the level of clogging. For example, a probe may be provided which checks the differential pressure level upstream and downstream of the grid 18 and sends an indication when such a level drops underneath a given threshold, indicating an excessive clogging of the grid.
Additionally, cleaning means may be provided adapted to at least partially clear the fibrous material intercepted by the weave of the grid 18. Such cleaning means (not shown in figures) may, for example, be vibrating means, suited to induce the detachment of the fibrous material from the grid 18 by shaking the grid itself. Such cleaning means may, for example, be automatically actuated according to the measurements carried out by the aforesaid sensor means.
Figure 4 shows a unit according to the present invention in a step of maintenance. The collection vessel 17 is detached from the lower portion 16 to which it is fixed to eliminate the fibrous material it contains, collected therein following the performed filtering operations. Specific detection means may be provided with specific detection means to indicate critical filling levels, such to require the intervention by an operator, at the container 17. Furthermore, the separation unit according to the present invention comprises a supporting structure 19 which allows to support it, and also preferably to fasten it to the floor of the room where it is installed.
Preferably, such a structure 19 comprises a plurality of vertical uprights which are fixed to the unit at a first end and to the floor at a second end. Furthermore, the vessel 17 may comprise suitable means to facilitate handling, e.g. a runner or a plurality of jointed wheels, to facilitate the emptying operations, in which the vessel 17 must be detached and handled.
Figures from 5 to 7 show a second embodiment of a unit 1 according to the present invention intended to be mounted on container bedding-air separation modules. Such container modules comprise a containment chamber 200, typically prism-shaped and made by means of metal sheet walls. Connection openings to connect to the ducts of the conveying plant are obtained in one of these walls.
Typically, two openings are present to connect to the bedding emptying duct (the latter is thus connected to a user, such as an unloading hopper) and to the pneumatic conveying duct connected to the vacuum pump for conveying, respectively. It is worth noting that in the aforesaid figures, one of the containment walls 200 is not shown in order to make the applied separation unit 1 clearly visible. A pressure condition is thus generated by means of the pneumatic conveying duct such as to aspirate the bedding which thus flow within the containment chamber 200. Unit 1 according to the present invention thus comprises: a first interface 11 at the bedding emptying duct 110, a second interface 12 applied at the sucking duct 160 and filtering means 10 interposed between the first interface 11a and the second interface 12a. The second interface 12a allows to couple the filtering means 10 to the portion of containment chamber 200 on which the access opening to the sucking duct 160 is defined.
The first interface 11a is arranged near the access opening to the emptying duct 110 and allows an optimal filtering of the fibrous material contained in the chamber 200, as will be described in greater detail below.
Figure 6 shows a second embodiment of the unit 1 according to the present invention. The first interface comprises a partition plate 21 fixed to the wall of the chamber 200 near the emptying duct 110, while the second interface comprises a supporting frame 22, also fixed to the wall of the chamber 200, in all cases differently from the plate 21 near the sucking duct 160.
The filtering means 10, which in the embodiment shown in the figure comprise a filtering box 28, are applied to the frame 22. Preferably, the box 28 comprises an appropriately performed metal surface 29 supported by a plurality of ribs 30. Figure 6 shows a preferred embodiment of the unit 1, in which the box 28 is appropriately shaped to guarantee a good filtering of the fibrous material. In the chamber 200, the heavier component of the bedding material 250 component (for example, the shaving portions) tends to deposit on the bottom 201, while the fibrous material 260 tends to detach from the bedding 250 and follow the aspirated air flow, i.e. go towards the sucking duct 160. For this purpose, the box 28 has an arched lower portion (i.e. the portion closest to the bottom 201) to increase the filtering surface and consequently improveefficiency.
The plate 21 at the opening for the bedding duct 110 allows to convey the bedding 250 within the chamber 200 and let it fall onto the bottom 201 to then filter only the fibrous material 260 by means of the box 28. Indeed, the maximum vacuum value produced in the vacuum pump can be identified precisely about the opening of the sucking duct 160. Furthermore, the opening of the sucking duct 160 is located near the opening for the bedding duct 110. Such a condition may make the heavier parts of the bedding components be aspirated directly by the duct 160 and deposited on the metal surface 29 of the box 28, causing rapid clogging up. The presence of the plate 21 prevents this disadvantageous situation, and thus allows to filter only the fibrous material 260 in optimal manner 28.
The dimensioning of the filtering box 28 follows this logic in order to optimize the fibrous material filtering. In particular, the weave according to which the holes in the metal surface 29 are arranged, their size and the height at which the box 28 is applied to the wall 201 of the chamber 200 are specifically chosen to optimize the filtering process of the fibrous material 260. Similarly to the grid 18 of the first embodiment (of figures 1 to 4), the metal surface 29 may integrate sensor means adapted to detect the level of clogging and integrated cleaning means adapted to clear at least partially the fibrous material intercepted according to the methods described above.

Claims

Separation unit (1) of fibrous materials, in particular of fibrous materials contained in bedding for animals, to be associated to a bedding-air separation module of a pneumatic bedding conveying plant, comprising:
- a first interface (11 a) associable to a first outlet duct (100, 110) of said bedding-air separation module;

- a second interface (12a) associable to a second suction duct (150, 160) of said bedding-air separation module;

- filtering means (9, 10) being interposed between said first interface (11 a) and said second interface (12a) and being configured to trap fibrous materials contained in said bedding material.
Unit according to Claim 1, characterized in that said filtering means (9) comprise a separation body (13) provided with a fluid inlet (11 a) and with a fluid outlet (12a), suitable to be applied to a cyclone bedding-air separation module, wherein said fluid inlet (11 a) of said body is connected to an outlet (100) of said cyclone bedding-air separation module and said fluid outlet (12a) of said body is connected to the sucking duct (160) of said pneumatic conveying plant.
Unit according to Claim 2, wherein said separation body (13) comprises, in succession:
- an upper portion (14) comprising said fluid outlet (12a);

- a central portion (15) connected to said upper portion (14) and comprising said fluid inlet (11 a);

- a filtering grid (18) inserted in said upper portion (14) or in said central portion (15);

- a lower portion (16) connected to said central portion (15) and adapted to collect said fibrous material trapped by said grid (18).
Unit according to Claim 3, wherein:
- said upper portion (14) is truncated cone shaped, comprises said fluid outlet (12a) on its upper end, and wherein the cross section of said truncated cone increases towards a lower end, opposed to said upper end, connected to said central portion (15);

- said central portion (15) is cylinder shaped and comprises said fluid inlet (11 a) in a tangential portion of its outer surface;

- said lower portion (16) is truncated cone shaped, and wherein the cross section decreases in a direction opposed to said upper portion (14).
Unit according to any one of Claims 2-4, wherein said filtering grid (18) is fastened inside said body (13) in correspondence of a junction area (15a) between said upper portion (14) and said central portion (15).
Unit according to Claim 1, wherein said filtering means (10) comprise a filtering box (28), said first interface (11 a) comprises a partition plate (21) close to said first duct (110), said second interface (12a) comprises a supporting frame (22) for said box (28) close to said second duct (160).
Unit according to Claim 6, wherein said filtering box (28) comprises a suitably punched surface (29), said surface (29) being supported by a plurality of ribs (30).
Unit according to Claim 6 or 7, wherein said filtering box (28) at least partially surrounds said second duct (160).
Unit according to any one of the preceding Claims, wherein said filtering means (9, 10) comprise sensor means adapted to detect the relative level of clogging.
Unit according to any one of the preceding Claims, wherein said filtering means (9, 10) comprise integral cleaning means adapted to release said fibrous material trapped by said filtering means.
Pneumatic bedding conveying plant of the kind comprising a bedding-air separation module, characterized in that it comprises a separation unit of fibrous materials according to any one of the preceding Claims.