Sowing Machine and Method for Separating and Spreading Granular Material

Abstract

A sowing machine and a method for separating and spreading granular material, such as seed or the like, are described, where the material is supplied by way of conveying airflows from a central container to metering devices via conveying ducts respectively associated with them. Furthermore, the material supplied in the conveying ducts is separated from the respective conveying airflow and the resulting discharge airflows are supplied via discharge air ducts to the respectively associated metering devices which are thus pressurized. Furthermore, the metering chambers are pressurized by way of supply airflows via supply ducts respectively associated with the former. The material is separated in the metering chambers by way of separating disks. Due to the fact that the supply airflows and the discharge airflows are fed into the metering chambers separately from one another, the required pressure level in the separating devices that generate the discharge airflows and thereby also the pressure level in the granular material dispensed from the separating devices to the metering devices can be reduced. This improves the separating quality of the metering devices.

Claims

1. A sowing machine for separating and spreading granular material, such as seed, fertilizer, pesticide, or the like, comprising: metering devices with metering chambers and separating disks arranged therein for separating said granular material; at least one blower for generating supply airflows for pressurizing said individual metering chambers via respectively associated supply ducts and for generating conveying airflows for supplying said granular material from a central container to said individual metering devices via respectively associated conveying ducts; and separating devices which are provided in the region of said metering devices upstream of said metering devices in order to separate the material supplied in said conveying ducts from the respective conveying airflow and to provide the resulting discharge airflows via discharge air ducts to said respectively associated metering devices for their pressurization, characterized in that said supply ducts and said discharge air ducts open out separately from one another into said metering chambers that are each jointly associated with the former.

2. The sowing machine of claim 1, where said discharge air ducts open out into said metering chambers, with respect to a conveying path of said separating disks, upstream of said supply ducts.

3. The sowing machine of claim 1, where said discharge air ducts open out into partial regions of said metering chambers in which a conveying path of said separating disks runs upwardly.

4. The sowing machine of claim 1, where scraping devices for scraping off said separating disks are arranged in said metering chambers and said discharge air ducts open out, with respect to a conveying path of said separating disks, upstream of said scraping devices and/or in their region.

5. The sowing machine of claim 1, furthermore comprising at least one air distributor arranged downstream of said blower for adjusting the conveying airflows and the supply airflows such that the discharge airflow respectively supplied to said individual metering devices is weaker than the supply airflow respectively supplied, in particular at most half as strong.

6. The sowing machine of claim 1, comprising at least one first blower for generating the supply airflows and at least one independently adjustable second blower for generating the conveying airflows, where said first and said second blower are configured and controllable such that the discharge airflow respectively supplied to said individual metering devices is weaker than the supply airflow respectively supplied, in particular at most half as strong.

7. The sowing machine of claim 1, furthermore with valves associated with said discharge air ducts and/or supply ducts for the adjustable weakening of the discharge airflows and/or supply airflows such that a mixing ratio of the discharge airflow and the supply airflow respectively supplied to said individual metering devices can be set.

8. The sowing machine, further comprising at least one measuring device for measuring a volume flow and/or an overpressure in at least one of said separating devices and/or discharge air ducts.

9. Method A method for separating and spreading granular material, such as seed, fertilizer, or pesticide, where said granular material is supplied from a central container to metering devices via respectively associated conveying ducts, where said granular material supplied in said conveying ducts is separated from the respective conveying airflow and the resulting discharge airflows are supplied via discharge air ducts to said respectively associated metering devices which are thereby pressurized, where said metering devices are pressurized via respectively associated supply ducts by way of supply airflows, and where said granular material is separated in said metering devices by way of separating disks, characterized in that the supply airflows and the discharge airflows are fed into said metering devices spatially separated from one another.

10. The method of claim 9, where the discharge airflows are fed in, in relation to a conveying stream of said granular material at said separating disks, upstream of the supply airflows.

11. The method of claim 9, where the discharge airflows are directed onto scraping devices for said separating disks present in said metering devices and/or partial regions of said metering devices located upstream thereof.

12. The method of claim 9, where the supply airflows fed in are stronger than the discharge airflows fed in, in particular at least twice as strong, and in particular have a volume flow twice to five times as large.

13. The method of claim 9, where pressure levels in said discharge airducts respectively prevailing during the separation are lower than in said supply ducts, in particular in associated sections immediately before being fed into said metering devices.

14. The method of claim 9, where the supply airflows and the conveying airflows are generated by way of separate blowers and/or by central airflow division downstream of at least one blower for generating a common total airflow.

Description

[0029] Preferred embodiments of the invention shall be illustrated by way of drawings, where:

[0030] FIG. 1 shows a schematic representation of the sowing machine with the airflow guidance described;

[0031] FIG. 2 shows a schematic representation of a metering chamber with the supply airflow and the airflow being fed in;

[0032] FIG. 3 shows the sowing machine according to FIG. 1 with alternative central airflow guidance.

[0033] As can be seen in FIG. 1, sowing machine 1 for separating and spreading granular material 2, such as seed, fertilizer, pesticide, or the like, comprises several metering devices 3 with metering chambers 4 and separating disks 5 arranged therein (indicated by the arrow for the direction of rotation) for separating granular material 2.

[0034] Furthermore, sowing machine 1 preferably comprises a first blower 6 for generating supply airflows 7 for pressurizing individual metering chambers 4 via supply ducts 8 respectively associated with them.

[0035] Furthermore, sowing machine 1 preferably comprises a second blower 9 for generating conveying airflows 10 for supplying granular material 2 to individual metering devices 3 via conveying ducts 11 associated with them. For this purpose, granular material 2 is made available in a known manner in a central container 12 at sowing machine 1.

[0036] Arranged on metering devices 3 upstream of the mass flow are separating devices 13 in which granular material 2 supplied in conveying ducts 11 is separated from conveying airflow 10 respectively loaded therewith. The separating results in substantially unloaded discharge airflows 14 which are supplied via discharge air ducts 15 to the respectively associated metering devices 3 in order to pressurize them.

[0037] Supply ducts 8 and discharge air ducts 15 open in a manner spatially separated from each other into jointly associated metering chambers 4 and preferably also into different regions of metering chambers 4.

[0038] FIG. 2 schematically shows one of metering chambers 4 with a separating disk 5 rotatable therein. A seed duct 16 through which granular material 2 arriving from above from separating device 13 moves onward into metering chamber 4 is also shown schematically. Granular material 2 can accumulate in a lower collection region 17 within metering chamber 4 for subsequent separation.

[0039] Shown only in sections are depressions 5a distributed over the entire circumference in the separating disk 5 in a known manner for receiving/separating granular material 2 as well as a scraping device 18 for scraping off separating disk 5. For the sake of completeness, a dispensing duct 19 for separated granular material 2 is also indicated, see also FIG. 1.

[0040] Starting out from the collection region 17, depressions 5a define a conveying path 20 (indicated by an arrow) of separating disk 5. Conveying path 20 runs substantially from collection region 17 to a dispensing point 21 at which separated granular material 2 leaves depressions 5a and is dispensed through dispensing duct 19 by metering device 3.

[0041] A feed opening 15a, being the first one with respect to conveying path 20, at which the discharge air duct 15 opens into metering chamber 4, and a feed opening 8a, being the second one with respect to conveying path 20, at which the supply duct 8 opens into metering chamber 4, are also shown by way of example.

[0042] First feed opening 15a (of discharge air duct 15) as well as scraping device 18 are therefore arranged in a region of metering chamber 4 in which conveying path 20 runs upwardly, i.e. in the direction toward seed duct 16.

[0043] Second feed opening 8a (of supply duct 8) is preferably arranged downstream of first feed opening 15a in a region of metering chamber 4 in which conveying path 20 of separating disk 5 runs downwardly again.

[0044] Alternatively, metering chamber 4 in FIG. 2 is divided horizontally/vertically into quadrants I to IV with respect to axis of rotation 5b of separating disk 5. As can be seen in this regard, first feed opening 15a is disposed, with respect to conveying path 20, preferably in the first quadrant I, scraping device 18 in the respective second quadrant II and second feed opening 8a in the respective third quadrant III. Alternatively, an arrangement of first feed opening 15a would also be conceivable in the region of the second quadrant II or at its transition to the first quadrant I.

[0045] The separate feeding of discharge airflow 14 through first feed opening 15a in the ascending part of conveying path 20, i.e. in first quadrant I and/or second quadrant II, enables particularly reliable covering of separating disk 5 with granular material 2 and/or selective blowing onto scraping device 18, for example, in order to remove residues of granular material 2 from holders for scraping elements or the like that are present thereon.

[0046] In contrast, the separate feeding of supply airflow 7 through feed opening 8a disposed downstream, i.e. in particular in third quadrant III, enables a separately adjustable basic pressurization of metering chamber 4 for separating granular material 2 at separating disk 5.

[0047] In this context, the direct fluidic connection in terms of flow technology between separating device 13 and first feed opening 15a via discharge air duct 15 is particularly advantageous, so that a comparatively low pressure level can be set therein as well as in separating device 13, without thereby reducing in an unfavorable manner the mass flow of granular material 2 that can be supplied with the respective conveying airflow 10 for which a certain pressure difference between blower 9 generating conveying flow 10 and separating device 13 must not be undercut. The pressure level in separating device 13 can therefore be kept as low as in metering device 3. This promotes separating disk 5 to be covered with granular material 2 in a proper manner and in particular also granular material 2 to be stirred efficiently by way of a stirrer 22 indicated only schematically in FIG. 2.

[0048] In addition to improving the separating quality, the individual compressed air flows can also be generated more efficiently than with the known combination of the supply airflows and discharge airflows upstream of the metering devices.

[0049] Sowing machine 31 in FIG. 3 is shown by way of example as an alternative embodiment, which differs from sowing machine 1 described above substantially only in the central air supply. According thereto, sowing machine 31 does not require a separate blower for supply airflows 7 and conveying airflows 10. For example, only first blower 6 or second blower 9 can instead be present for this purpose as well as a central air distributor 32 arranged downstream thereof which divides a total airflow 33 (presently generated by blower 6 by way of example) into supply airflows 7 and conveying airflows 10.

[0050] For this purpose, blower 6 as well as central air distributor 32 can preferably be controlled/regulated by a controller 34 shown by way example, so that, firstly, total airflow 33 and, secondly, its division into supply airflows 7 and conveying airflows 10 can be adjusted.

[0051] Optionally, a valve 35 for attenuating discharge airflow 14 or supply airflow 7 that is passed through could additionally be present in each of discharge air ducts 15 and supply ducts 8. As a result, respective discharge airflow 14 and/or supply airflow 7 could be additionally reduced independently of the pressure level prevailing at the inlet side in associated separating device 13. A mixing ratio of discharge airflow 14 respectively supplied to individual metering devices 3 and supply airflow 7 can then be adjusted.

[0052] Also indicated schematically are measuring devices 36, 37 for measuring an overpressure in at least one of separating devices 13 and/or for measuring a volume flow in at least one of discharge air ducts 15. Discharge airflows 14 can thereby be controlled/regulated in a selective manner under different operating conditions in the region of separating devices 13.

[0053] It presently goes without saying that controller 34, valves 35, and/or measuring devices 36, 37, which are shown only by way of example in FIG. 3, are likewise present at sowing machine 1 previously described in order to control/regulate blowers 6, 9 and thereby supply airflows 7, conveying airflows 10 and ultimately also discharge airflows 14 that are generated separately thereby.

[0054] During operation of sowing machine 1, 31, supply airflows 7 respectively fed into metering chambers 4 are preferably stronger than discharge airflows 14 fed in at the same time. It has been found to be advantageous to adjust at least one of blowers 6, 9 and/or central air distributor 32 and/or valves 35 such that supply airflows 7 are each at least twice as strong as associated discharge airflows 14 A ratio of 1:2 to 1:5 of discharge airflow 14 respectively fed in to supply airflow 7 respectively fed into same metering device 3 has proven to be particularly practical. This value preferably relates to the ratio of the respective volume flows.

[0055] This allows the separating quality of granular material 2 ultimately dispensed by sowing machine 1, 31, i.e. in individual dispensing ducts 19, to be optimized comparatively flexibly, for example, with regard to different granular goods 2 and/or operating conditions.