ACTIVE SYSTEM FOR OPTIMIZATION AND PLUGGING AVOIDANCE OF SEED/FERTILIZER IN TRANSPORT CONDUCTS

Abstract

An agricultural implement has a product supply chamber, and a pair of transversely extending product delivering booms, each with a plurality of conduits of varying lengths terminating in product distributing nozzles. A fan supplies air to a mixing chamber which also receives product from the supply chamber providing an air entrained flow of product to each conduit. A controller monitors product delivery and controls implement operation. Each conduit has a pressure tap near the nozzle for providing the controller with a pressure differential indication. The controller initiates a corrective action modifying the operation of the delivery system when a predetermined pressure differential threshold is exceeded. The corrective action may include an increased air flow volume, an additional burst of higher pressure air into the conduit, a temporary increase in air flow from the air flow source, or a reduction in the rate of product flow from the supply chamber.

Claims

1. A process of monitoring an air/particle mixture movement through an elongated agricultural product delivery system conduit to optimize the rate of product delivery, comprising: measuring the pressure differential along the conduit; comparing the measured pressure differential and a predetermined threshold pressure differential; and initiating a corrective action when the comparison indicates imminent conduit blockage.

2. The process of claim 1, wherein the corrective action comprises modifying the delivery system operation.

3. The process of claim 2, wherein the delivery system is modified by temporarily reducing the rate of agricultural product flow through the conduit.

4. The process of claim 1, wherein the corrective action comprises temporarily augmenting the air flow in the conduit.

5. The process of claim 1, wherein the corrective action, wherein the corrective action maintains product flow near maximum at all times without allowing the conduit to become blocked.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

[0012] FIG. 1 is an isometric view of an air spreader system for agricultural products such as fertilizer incorporating the invention in one form;

[0013] FIG. 2 is a top view of the air spreading system of FIG. 1;

[0014] FIG. 3 is an isometric view of the right boom of FIGS. 1 and 2;

[0015] FIG. 4 is an isometric view of a portion of the boom of FIGS. 1-3 from a different orientation including schematic controls;

[0016] FIG. 5 is a schematic illustration of the operation of the system of FIG. 4; and

[0017] FIGS. 6A through 6D are graphs of exemplary air blast profiles for a pneumatic product delivery system.

[0018] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

[0019] Referring now to the drawings, and more particularly to FIGS. 1 and 2, there is shown an agricultural implement 10 such as an air fertilizer spreader which generally includes a large tired transport unit such as truck or tractor, self propelled by an engine within the engine compartment 12, and having a pair of laterally extending particle delivery booms 14 and 16. As is known in the art, these booms may be pivotable to a stowed position close to the implement for storage or transport. Each boom includes a plurality of boom tubes or conducts terminating at the outboard end in a fertilizer spreading outlet or nozzle 18-32. Additionally, there are rear nozzles such as 31 and 33. The implement transport unit 34 includes an operator cab 36 and a pair of hopper compartments 38 and 39. The fertilizer spreader of FIGS. 1 and 2 is illustrative and the invention may, of course, be employed in conjunction with other agricultural equipment such as tilling or planting devices and is useful in distributing particulate material other than fertilizer.

[0020] FIG. 3 shows the right (from the operator's viewpoint) boom 14 in greater detail. It will be understood that the left boom 16 may be a mirror image thereof. The inboard end of the boom includes a mixing chamber such as venturi box 40 which receives from an air flow source, such as a fan 42, an input air flow 44 to be mixed with a metered flow 46 of fertilizer or other particulate material from a drop chute. Additional air flow from a compressor may be introduced automatically or under operator control. The air and entrained particles are forced under air pressure down the individual boom tubes and from the nozzles onto the agricultural field surface. Each boom tube or conduit includes an outlet pressure tap 48-62 for providing an indication of the air pressure at that individual outlet to the control system. A similar upstream pressure tap 64 provides an indication of conduit inlet pressure which may be considered as common to all the boom tubes or each individual tube may have its own inlet pressure tap.

[0021] As shown in FIG. 4, air inlet pressure tap 64 and outlet tap 48 are coupled to a controller 66. Each pressure tap may include a transducer for providing and electrical pressure indicative output to the controller, or air passageways from respective inlet and outlet taps may be coupled to a pressure differential measuring device which, in turn, feeds pressure differential information to the controller. The controller 66 provides outputs to the fan control 68, the pneumatic pressure source 70 and to a mechanism 72 for temporarily reducing the particle flow 46 requirements from the hopper 74. The pneumatic pressure source 70, such as a compressor with a conventional pressure tank or accumulator, is normally inactive, but may be energized to provide a temporary burst of air into the conduit near the conduit inlet and directed somewhat downstream when the pressure differential between the taps 48 and 64 indicates incipient conduit blockage. This pneumatic source may derive air pressure from air source (fan) 42 or may comprise an independent unit. The controller 66 may utilize a common inlet pressure indication on line 76 or may receive individual conduit inlet pressure information as indicated generally at 78, however, individual outlet pressure information for each conduit as indicated at 80 is desirable. Typically, pneumatic source 70 is dedicated to conduit 82 with the other conduits receiving air bursts from further pneumatic pressure sources as triggered by signals on additional controller output lines indicated generally at 84. The pneumatic source may be common to several or all conduits, in which case, those conduits will all receive a corrective burst of air.

[0022] In a preferred embodiment, the system has both a fan and an air compressor. The pneumatic source (air compressor) 70 produces an air flow at a higher pressure than the fan 42. The fan runs continuously and the air boost from the compressor air accumulator runs on demand at near plugging conditions using various air pressure patterns. The system can also speed up the fan to provide in general a larger air flow rate, but the response time is slower than with the compressed air to break up a wad of near-stopped particles.

[0023] The controller 66 operation is summarized in FIG. 5. The controller monitors static pressure in each tube or conduit and provides the operator with an indication thereof on in-cab display 86 that shows the air pressure drop (for example, in inches of H.sub.2O). The operator typically sets a plugging level and a level of tolerance percentage at 88 and when the measured pressure drop (pressure differential) 90 exceeds the set values, command 92 initiates the triggering 94 of pneumatic pressure source for the offending conduit. Various patterns for the air blast may be operator set as shown at 96.

[0024] Exemplary air blast patterns are shown in FIGS. 6A-6D. The blasts are shown as lasting 5 seconds, however, other blast durations may be employed. FIG. 6A illustrates a blast having a relatively long period of one-half second. FIG. 6C shows a more staccato-like repetition rate about double that shown in FIG. 6A. A repetition rate intermediate those of FIGS. 6A and 6C is shown in FIG. 6B while a pattern random in both repetition rate and amplitude is shown in FIG. 6D. Other patterns and rates are clearly possible. Air blast patterns of a similar nature are disclosed in the Roberge et al U.S. Pat. No. 8,651,927 B1. In this patented arrangement, the air blasts are employed as part of an improved combine harvester separating and cleaning system. The avoidance of resonance and shock waves in the conduits is an advantage of the random air blast pattern.

[0025] The controller 66 is further operative to optimize the rate of product delivery by measuring 90 the pressure differential along the conduit and comparing 98 the measured pressure differential to a predetermined threshold pressure differential. When that threshold is reached indicating imminent conduit blockage, a corrective action 100 is initiated. The corrective action comprises modifying the delivery system operation by any suitable technique as by reducing the rate of agricultural product flow through the conduit, for example, by reducing the implement ground speed 102. Implement ground speed may be reduced by slowing the engine 12, or by varying the implement or traction unit transmission ratio either manually or utilizing any suitable protocol like ISOBUS. The corrective action may also include temporarily augmenting the air flow in the conduit as by increasing air flow 104 from the fan 42, or providing a short air blast 106 from pneumatic source 70. The fan 42 may temporarily provide the function of pneumatic pressure source 70 employing one or more solenoids to release air into all or selected ones of the air boosters, but an air compressor is preferred for its quick response time. The corrective action is intended to maintain product flow near maximum at all times without allowing the conduit to become blocked.

[0026] While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.