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EP-3945768-B1 - SUPPLY ASSEMBLY FOR A PNEUMATIC GRAIN SEPARATOR DEVICE

EP3945768B1EP 3945768 B1EP3945768 B1EP 3945768B1EP-3945768-B1

Inventors

  • LUEBBEN, Jan-Eike
  • Flucke, Jan
  • WIEN, THOMAS

Dates

Publication Date
20260513
Application Date
20200311

Claims (13)

  1. Supply assembly (10) for a pneumatic grain singulation device (100) of an agricultural seed drill, comprising - an assembly housing (12) which has a separation region (26) into which a feed airflow loaded with granular material (M) can be introduced; - a separation device arranged in the separation region (26) for separating the granular material (M) from the feed airflow, - an introducing device (30) arranged in the assembly housing (12), via which device the feed airflow can be introduced, after the granular material (M) has been separated, into a supply airflow for the grain singulation device (100); and - a through-channel (18) within the assembly housing (12), via which through-channel the supply airflow can be passed through the assembly housing (12); characterized by a flow divider (20) which is configured to divide a transport airflow loaded with granular material (M) into two feed airflows and to direct one feed airflow to the separation region (26) of the assembly housing (12), the through-channel (18) being connected to a bypass channel (32) which connects a channel segment of the through-channel (18) arranged upstream of the introducing device (30) to a channel segment of the through-channel (18) arranged downstream of the introducing device (30).
  2. Supply assembly (10) according to claim 1, characterized in that the flow divider (20) is at least partially arranged outside the assembly housing (12) and/or is configured to divide the transport airflow loaded with granular material (M) into the two feed airflows outside the assembly housing (12).
  3. Supply assembly (10) according to either claim 1 or claim 2, characterized in that the flow divider (20) has an inlet flow channel (22) for the transport airflow, which channel splits at a branch point or branch region (36) into two outlet flow channels (24a, 24b) for the feed airflows, the inlet flow channel (22) and the two outlet flow channels (24a, 24b) preferably forming a Y-shaped basic form.
  4. Supply assembly (10) according to claim 3, characterized in that a first outlet flow channel (24a) projects into the separation region (26) of the assembly housing (12) and/or a second outlet flow channel (24b) leads away from the assembly housing (12) or out of the assembly housing (12), in particular the second outlet flow channel (24b) running substantially mirror-symmetrically to the inlet flow channel (22).
  5. Supply assembly (10) according to claim 4, characterized in that the first outlet flow channel (24a) has a channel length (L) which is less than twice the diameter (d1) of the inlet flow channel (22) or which substantially corresponds to the diameter (d1) of the inlet flow channel (22).
  6. Supply assembly (10) according to either claim 4 or claim 5, characterized in that the diameter (d1) of the inlet flow channel (22) is larger than the diameter (d2) of the first outlet flow channel (24a) and/or larger than the diameter (d3) of the second outlet flow channel (24b) or corresponds to the diameter (d2) of the first outlet flow channel (24a) and/or the diameter (d3) of the second outlet flow channel (24b).
  7. Supply assembly (10) according to any of the preceding claims, characterized in that the through-channel (18) comprises the introducing device (30) and has channel segments upstream and/or downstream of the introducing device (30), the diameters (D1, D2) of which segments are larger than the diameter (d1) of the inlet flow channel (22) of the flow divider (20).
  8. Supply assembly (10) according to any of the preceding claims, characterized in that a flow control device (34) is arranged within the bypass channel (32), by means of which the bypass channel (32) can be partially or completely blocked and/or opened, in particular the free flow cross-section within the bypass channel (32) being changeable via the flow control device (34).
  9. Supply assembly (10) according to any of the preceding claims, characterized in that the separation device has a grain collecting body (28) within which the granular material (M) separated from the feed airflow collects, the grain collecting body (28) having one or more vent openings for the feed airflow.
  10. Supply assembly (10) according to claim 9, characterized in that the grain collecting body (28) has a filling region for the granular material (M) separated from the feed airflow, the filling region defining a maximum filling height (F), the sum (S) of half the maximum filling height (F) and the part of the first outlet flow channel (24a) of the flow divider (20) projecting from the assembly housing (12) being less than four times the diameter (d1) of the inlet flow channel (22) of the flow divider (20).
  11. Supply system for at least two pneumatic grain singulation devices (100) of an agricultural seed drill, comprising - a first supply assembly (10) which is configured to provide a supply airflow and granular material (M) to a first pneumatic grain singulation device (100); and - a second supply assembly which is configured to provide a supply airflow and granular material (M) to a second pneumatic grain singulation device; characterized in that the first supply assembly (10) is designed according to any of the preceding claims and the flow divider (20) of the first supply assembly (10) is configured to direct a feed airflow to the separation region (26) of the first supply assembly (10) and to direct another feed airflow to a separation region of the second supply assembly.
  12. Supply system according to claim 11, characterized in that the second supply assembly, with the exception of the flow divider (20), is designed according to any of claims 1 to 12.
  13. Seed drill comprising - at least one supply system which is configured to provide a supply airflow and granular material (M) to each of two pneumatic grain singulation devices (100); - at least two pneumatic grain singulation devices (100), each connected to a supply assembly (10) of the supply system and configured to singulate grains from the granular material (M) provided by the supply system using a pressure difference generated by the supply airflow provided by the supply system; and - at least two seed coulters for depositing singulated grains on an agricultural area; characterized in that the supply system is designed according to either claim 11 or claim 12.

Description

The invention relates to a supply unit for a pneumatic grain singulation device according to the preamble of claim 1, a supply system for at least two pneumatic grain singulation devices according to the preamble of claim 11 and a seed drill according to the preamble of claim 13. Seed drills with pneumatic seed singulation typically have several pneumatically operated seed singulation units that separate grains from a granular material using a pressure differential generated by a supply air stream. The granular material and the supply air stream are provided to the seed singulation units by a supply system with multiple supply units, with each seed singulation unit usually having its own supply unit. The seeds separated by the seed singulation units are then deposited onto agricultural land via the seed drill's coulters. Typical seed supply units usually have a housing, the housing of which includes a separation area into which a seed-laden supply airflow can be introduced, as shown, for example, in the US 2010 0 313 800 A1 A separator located in the separation area separates the seed from the feed airflow, causing seed to accumulate in the separator area. This seed is then fed to the singulation unit. In some unit designs, an inlet device is located within the unit housing, allowing the seed-separated feed airflow to be introduced into a supply airflow for the singulation unit, as described in the... WO 2013 180 620 A1 shows. A similar power supply unit is in the WO 2013 180 619 A1 shown. Such systems are particularly used in the Overpressure singulation is used. The supply airflow is then directed to the grain singulation device. which then performs the particle singulation based on a pressure difference generated by the supply air flow. In conventional seed-singling units, the seed separated from the supply air stream accumulates in the separation area of the unit housing or the supply line to the separation area during operation. This can lead to the development of back pressure in the separation area or its supply line. Due to this back pressure, pressure fluctuations can occur in the supply air stream leading to the seed singulation unit in systems where the supply air stream is not separately discharged from the unit housing after seed separation. These pressure fluctuations can significantly impair the operation of the seed singulation unit, potentially resulting in gaps or interruptions in the seed rows during sowing. The object of the invention is therefore to avoid or at least reduce pressure fluctuations in the supply air stream of a pneumatic seed singulation unit. The problem is solved by a power supply unit with the features of claim 1. The invention utilizes the knowledge that pressure fluctuations in the supply air flow to the grain singulation device can be effectively avoided or at least significantly reduced by using a flow divider. Depending on the fill level of granular material in the separation area, and thus depending on the back pressure caused by grain accumulation, the flow divider results in a self-regulating division of the transport air flow into the two supply air flows. The self-regulating properties depend on the design of the The flow divider is designed such that a first supply airflow initially contains a portion of the granular material from the transport airflow, and a second supply airflow initially contains a portion of the granular material from the transport airflow. For example, the flow divider can be designed such that a first supply airflow initially contains 90% of the granular material from the transport airflow, and a second supply airflow initially contains the remaining 10%. As the dynamic pressure in the flow path of the first supply airflow increases, caused by a build-up of particles in the separation zone, the proportion of granular material in the second supply airflow increases. Simultaneously, as the dynamic pressure in the flow path of the first supply airflow increases, the proportion of granular material in the first supply airflow decreases. The flow divider thus causes a dynamic pressure-dependent and self-regulating diversion of the granular material. The second supply airflow, which is not directed to the supply unit on which the flow divider is located, can then be directed to another supply unit for a further pneumatic seed singulation unit of the agricultural seed drill. This prevents a build-up of granular material in the supply line and thus the development of excessive back pressure, which would cause the supply airflow to stall. The flow divider therefore prevents a collapse in the delivery pressure in the supply line to the supply unit when the granular material in the separation zone exceeds a critical fill level. This also significantly reduces pressure fluctuations in the supply air for the seed singulation unit, as a drop in the supply airflow caused by a build-up of grain in the supply line to the supply unit is prevented or a