Air seeder distribution apparatus with purging air

Abstract

An air seeder distribution apparatus has a manifold and a plurality of delivery conduit connected to ports of the manifold. A supply conduit carries a product air stream and is connected the manifold interior. A port valve when open connects a delivery conduit to the manifold interior through the port and disconnects same when closed. A purging conduit connects the supply conduit, at a clean air location configured to receive from the supply conduit a clean air stream with no agricultural products entrained therein, to the delivery conduit such that the clean air stream has an open path from the supply conduit to the delivery conduit. When the port valve is open the clean air stream flows through the purging conduit at a low first flow rate, and when the port valve is closed the clean air stream flows through the purging conduit at a second significantly greater flow rate.

Claims

1. An air distribution apparatus for an air seeder, the apparatus comprising: a manifold body, and a plurality of ports defined through a wall of the manifold body; a delivery conduit connected at an input end thereof to each port; a supply conduit connected at an output end thereof to an interior of the manifold body, and connected at an input end thereof to receive a product air stream with agricultural products entrained therein; on at least a first port, a port valve configured such that when the port valve is open, a corresponding first delivery conduit is connected to an interior of the manifold body through the first port and a first portion of the product air stream flows through the first delivery conduit, and such that when the port valve is closed, the first delivery conduit is disconnected from the interior of the manifold body; a purging conduit connected at an input end thereof to the supply conduit at a clean air location configured to receive from the supply conduit a clean air stream with substantially no agricultural products entrained therein, and connected at an output end thereof to the first delivery conduit in proximity to the first port such that the clean air stream has an always open path from the supply conduit to the first delivery conduit; and wherein while the port valve is open the clean air stream flows through the purging conduit at a first flow rate, and while the port valve is closed the clean air stream flows through the purging conduit at a second flow rate that is greater than the first flow rate.

2. The apparatus of claim 1 wherein the supply conduit extends substantially vertically up from the manifold body to a curved elbow and then extends substantially horizontally from the elbow, and wherein the clean air location is at an inner radius of the elbow.

3. The apparatus of claim 1 wherein the first delivery conduit is connected at an output end thereof to a secondary manifold.

4. The apparatus of claim 1 wherein the first delivery conduit is connected at an output end thereof to a furrow opener.

Description

DESCRIPTION OF THE DRAWINGS

(1) While the invention is claimed in the concluding portions hereof, preferred embodiments are provided in the accompanying detailed description which may be best understood in conjunction with the accompanying diagrams where like parts in each of the several diagrams are labeled with like numbers, and where:

(2) FIG. 1 is a schematic cut-away side view of an embodiment of the air distribution apparatus of the present disclosure with the first port valve open;

(3) FIG. 2 is a schematic cut-away side view of the embodiment of FIG. 1 with the first port valve closed;

(4) FIG. 3 is a schematic top view of the manifold body of the embodiment of FIG. 1;

(5) FIG. 4 is a schematic side view showing the first delivery conduit connected directly to a furrow opener.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

(6) FIGS. 1 and 2 schematically illustrate an embodiment of an air distribution apparatus 1 of the present disclosure. The apparatus 1 is shown as part of an air seeder product distribution network. The apparatus 1 comprises a manifold body 3 comprising substantially circular top and bottom plates 5, as illustrated in FIG. 3, oriented substantially horizontally, and a substantially vertical body wall 7 extending between the top and bottom plates 5A, 5B. Ports 9 are defined through the body wall 7, and a delivery conduit 11 is connected at an input end thereof to each port 9.

(7) A substantially vertically oriented supply conduit 13 is connected at an output end 13A thereof to the interior of the manifold body 3 through an aperture 15 in the top plate 5A. The supply conduit 13 extends substantially vertically up from the manifold body 3 to a curved elbow 17 and then extends substantially horizontally from the elbow 17 to an input end 13B thereof that is connected to receive a product air stream PAS with agricultural products 19 entrained therein. The product air stream PAS is provided by a conventional air seeder fan and metering system.

(8) A port valve 21 is configured such that when the port valve 21 is open, as shown in FIG. 1, the corresponding first conduit 11 is connected to the interior of the manifold body 3 through a first port 9 and a first portion PAS' of the product air stream PAS flows through the first delivery conduit 11 to a downstream secondary manifold 23 which divides the first portion PAS' of the product air stream PAS into separate air streams to each of a plurality of furrow openers 25 as is known in the art. The first portion PAS' of the product air stream PAS will be a proportion of the total product air stream PAS substantially corresponding to the number of ports 9.

(9) When the port valve 21 is closed, as shown in FIG. 2, the first delivery conduit 11 is disconnected from the interior of the manifold body 3 and no part of the product air stream enters the first delivery conduit 11. The air seeder system will typically be configured to correspondingly reduce the amount of entrained agricultural products in the product air stream PAS to maintain a constant application rate of agricultural products across the width of the air seeder.

(10) A purging conduit 27 is connected at an input end 27A thereof to the supply conduit 13 at a clean air location 29 configured to receive from the supply conduit 13 a clean air stream CAS with substantially no agricultural products entrained therein. In the illustrated apparatus the clean air location 29 is at an inner radius of the elbow 17. The velocity of the product air stream PAS causes the agricultural products to follow the outer radius of the elbow 17 when turning from the horizontal to the vertical direction, such that little if any product is present at the inner radius, and a clean air supply can be obtained.

(11) The purging conduit 27 is connected at an output end 27B thereof to the first delivery conduit 11 somewhere in general proximity to the first port 9 such that the clean air stream CAS has an open path from the supply conduit 13 to the first delivery conduit 11.

(12) When the port valve 21 is open as in FIG. 1, the air pressure of the first portion PAS' of the product air stream PAS is present at the output end 27B of the purging conduit 27, which pressure is only slightly less than the air pressure of the product air stream PAS at the clean air location 29. The pressure difference is due to pressure losses as the product air stream PAS passes through the manifold body 3 and port 9, but in any event the pressure differential is small and the clean air stream CAS flows through the purging conduit 27, and then through the first delivery conduit 11 with the first portion PAS' of the product air stream PAS, at a first flow rate that is virtually negligible for the purposes of the apparatus 1 and does not adversely affect air flows in the apparatus 1.

(13) When the port valve 21 is closed, the air pressure of the first portion PAS' of the product air stream PAS is removed from the output end 27B of the purging conduit 27 and the air pressure of the product air stream PAS at the clean air location 29 causes the clean air stream CAS to flow through the purging conduit 27 and the first delivery conduit 11 at a second flow rate that is much greater than the first flow rate, and comparable to the rate of air flow in the first portion PAS' of the product flow rate PAS since the air pressure at the output end 27B of the purging conduit is then about the same as at the clean air location 29, which as described above is very close to the air pressure of the first portion PAS' of the product air stream PAS when the port valve 21 is open.

(14) Thus the air flow through the supply conduit 13 remains substantially the same whether the port valve 21 is open or closed, and problems of reduced air flow in the supply conduit 13 are avoided.

(15) FIG. 4 schematically illustrates an alternate arrangement where the first delivery conduit 11 is connected at an output end thereof directly to a furrow opener 25 which may in some cases be preferred in order to stop and start the flow of agricultural products to each furrow opener 25 independently.

(16) The present invention thus maintains air speed of the product air stream PAS above a critical velocity in the distribution network as ports 9 are closed and opened, and provides a purging clean air stream CAS to clear agricultural products 19 from delivery conduits 11 and manifolds 23 downstream of a closed port valve 21. The present apparatus 1 is simple and less costly to make compared to the prior art system where a two way valve with appropriate controls is required to simultaneously open the purging air conduit while closing the port valve. In the present apparatus 1 only a simple on/off port valve 21, with appropriate simple controls is required. The purging air flow is constantly present and the flow rate thereof increases to purge the delivery conduits 11 when the corresponding port valves 21 close, and drops to a negligible amount when the port valves 21 open.

(17) The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous changes and modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all such suitable changes or modifications in structure or operation which may be resorted to are intended to fall within the scope of the claimed invention.