FR2643575A1 - PRESSURIZED PNEUMATIC SYSTEM FOR THE UNIFORMLY DISTRIBUTION OF PARTICULATE SOLIDS ON THE SOIL - Google Patents

Abstract

The invention relates to a pressurized pneumatic system for agricultural machines for spreading particulate solids. The system includes a venturi 26 formed by a wedge-shaped body 27 which defines an inlet ramp 28, an outlet ramp 29, a throat portion 30, and a blade 32. The venturi 26 is placed in a section 20 of the feed boom, in the immediate vicinity and slightly upstream of the junction point of a tubular feed element 22A with the section 20. Field of application: systems for spreading chemicals for the treatment of crops, soils, etc.

Description

The invention relates generally to a pneumatic system

  advanced spreading machine for dispensing

  particulate matter or pulverulent solids

  the system is less prone to sealing and provides a more uniform distribution of solids by means of arrows of various lengths in a given dispenser. Pneumatic pressure systems for the distribution of particulate solids are known and have been

  used for this purpose in the past. However, the incon-

  the systems currently in use is that sometimes particulate solids

  dispensing tube or are unloaded irreversibly

  regular by the distributor system.

  Agricultural techniques require the use of

  use of soil treatment agents to promote, inhibit, destroy or inhibit plant growth. Such agents can generally be characterized as crop-treating chemicals and include such materials as nutrients, for example fertilizers, and pesticides such as insecticides, and plant growth inhibitors acting before or after lifting. In other words, the term "crop processing chemical" is used in a general sense to encompass the various ingredients used in agriculture to treat soils, plants or insects. Active ingredients used for treatment commonly occur in one of three forms, namely a water-soluble form, a

  form wettable by water or a solid form in particular

  ticles. With regard to the present invention,

  Particle or granular solids are

  The system of the invention is particularly suitable for use in connection with the distribution of

  these materials on the floor or other surfaces to be treated.

  In the treatment of agricultural fields and crops by spreading an active treatment ingredient, the efficiency of the treatment operation can be improved by reducing the load to be carried. Therefore, the use of dry particulate solids substantially reduces the required load, since water or other treatment agent or vehicle is not required. The use of pressurized pneumatic systems normally eliminates the need to use water and, with pneumatic systems, a compressor is normally used instead of a source of pressurized liquid for supplying the ingredient. of

treatment.

  A common problem with pressurized pneumatic systems for material distribution

  solid particles or granules is that of the uniform

  mity of the distribution. One factor leading to a lack of uniformity in the distribution is a tendency of the granulated materials to become lodged in the distribution system, thus partially or totally blocking part of the system. This obviously hinders the normal flow of air into the system. The pneumatic pressurized system normally uses a plurality of elongate and hollow feed arrows, these arrows being of predetermined and different lengths and extending laterally outwardly of the carrier vehicle. By extending the length of the individual and elongated feed arrows on each side of the vehicle, it is possible to

  correspondingly increase the area covered.

  However, when the length of the arrows increases, it is

  appeared that problems with filling, ac-

  cumulation of materials and the resulting lack of uniformity

  of distribution increased proportionally.

  It has been found that the features of the invention reduce the tendency to seal and thus improve the uniformity of particle solids distribution from the system and onto the soil, the system having been shown to decrease the accumulation in parts of said system, in particular parts of the feed arrows. It appeared that the classical system was experiencing congestion and accumulation of materials, particularly at the point of introduction of

  granulated material in the air flow. The particulars

  of the invention have been found desirable for improving the performance of systems using

  arrows elongated and hollow discharge or supply.

  Briefly, in accordance with the invention, there is provided an improved system for applying granular chemicals, which system improves the performance of pneumatic systems under application pressure by providing substantially uniform distribution of particulate solids. on the soil surface. The improved system is advantageously mounted on a vehicle such as a self-propelled vehicle comprising either a tractor or a trailer chassis, the system comprising a reservoir with a feed source of agricultural crop processing chemicals, in the form of granules or solid particles to be dispensed, for example a nutrient such as a fertilizer and / or a pesticide such as an insecticide or herbicide, the system also having a spreader or dispensing mechanism. The system comprises a number of conventional elements including: (a) a tank or hopper for containing a reserve of particulate solids; (b) means for transporting particulate solids to a dispensing head where the feed material is dosed divided into a number of aliquots; (c) means for bringing the dosed aliquots to the arrows; and (d) means, such as a blower, for supplying compressed air to move the material out of the arrows to a discharge point. By briefly and individually considering these elements, a dispensing head is provided, as indicated, for receiving a solid particulate feed and for metering and distributing these solids in several generally aliquot portions. These dispensing heads are well known in the art and the present system is well suited for use with any of these various heads. Several elongated and hollow discharge or delivery arrows are used in the system, the proximal end of each arrow being connected to a source of air under pressure or compressed and receiving air from this source, for example a chamber of tranquilization which, itself, receives its charge of air from a blower. A tubular duct or supply tube is connected to the outlet of the dispensing head and is adapted to carry an aliquot to a junction point in close proximity to the inner or proximal end of an arrowhead. discharge or delivery, at a point near and immediately downstream of the proximal end of the boom. The flow of air passing through the arrows thus has two functions, one function being to transport the granular material to the point of discharge of the arrow and the other function being to generate a partial vacuum in the tubular conduit or the tube feed for injecting granular solids into the air stream. Each duct or tubular supply element thus brings an aliquot portion of the dispensing head into the arrow, the compressed air transporting or displacing the particulate solids towards the outside.

  to the point of delivery at the end of the arrow.

  To improve the introduction and the transfer of solid matter in particles or granules in the boom, in particular at the point of injection, improved venturi means are provided according to the invention. The advanced venturi is mounted in each of the arrows at a point immediately upstream and in the immediate vicinity of the junction of the arrow with the element

tubular supply.

  The venturi means comprise a flow wedge that includes an inlet ramp portion, an exit ramp portion, and a groove portion located between the inlet and outlet ramps. The throat portion is adapted to extend generally along a rope traversing the extent of the cross section of the hollow feedthrough. In addition, a blade means is provided to be generally opposed to the throat portion of the venturi, the blade means having an outer edge which itself extends generally along a rope traversing the boom and which is roughly parallel to the rope defined by the throat of the venturi. The blade means further extends radially inwardly of the boom and at an angle so as to converge towards the distal end of the boom. The opening that is defined between the inner edge of the blade and the surface

  the ramp of the venturi is substantially rectangular.

  This rectangular configuration of the section or open area provides a means of equalizing the flow of air over the entire opening within the boom, this feature being found to significantly reduce any tendency of the granular material to accumulate in the venturi zone and thus contribute to the filling. The axial position of the blade means along the boom is such that the inner edge of the blade, in addition to being opposed to the throat of the venturi, intersects at least a portion of an imaginary projection of the tubular member feeding from its intersection with

the hollow arrow of supply.

  Whereas known pneumatic pressure spreading systems in the past included venturis to assist in the distribution of particulate solids and to assist in the introduction of particulate solids into the arrows, the venturi means used in the past were, in particular, normally formed by the introduction of the tubular feed element over a certain distance within the boom, thus forming a partial constriction. The configuration of the open section generated in this manner was generally crescent shaped, with the ends tapered inward. Such a configuration appeared to contribute significantly to the closure, in particular at the ends and in the immediate vicinity of the ends of the opening in the form of

  increasing. The present arrangement of the venturi, the configuration

  its strangulated opening being generally

  gular, is designed to maintain an even and continuous flow of air and solids in the system to prevent clogging of the boom by

  granular material or particulate solids.

  The blade is designed to be normally set up and its position is set to provide even distribution of particulate solids in the boom. However, the blade may be adjustably positioned in response to variations in flow rates achieved or encountered from the downstream sections of one or more of the arrows. With regard to the system of the invention, it has been found that the venturi / blade combination and the configuration of the constriction which it forms help to achieve a smooth and positive flow of solids entering the boom. In other words, the blade gives the groove a configuration and a dimension to achieve a constant, continuous and predictable flow to help control and move particulate solids in and through them.

structures of elongated arrows.

  The main object of the invention is therefore an improved system for dispensing a granular material or particulate solids from a pressurized pneumatic system, in which improved venturi means are mounted in position to bring more uniform and more continuous particulate solids in the flow of air under pressure

  browsing each of the arrows.

  Another object of the invention is to propose

  an advanced venturi system to be used in combination with

  with pressurized pneumatic systems for the distribution of particulate solids, the system comprising a venturi mounted within each of

  several hollow feed arrows, and the venturi

  a cooperating blade which is mounted to oppose the throat portion of the venturi and which is adapted to regulate the flow of air and the introduction of particulate solids into the air flow

browsing the system.

  Another object of the invention is to provide an improved pneumatic system under pressure for the distribution of particulate solids on an agricultural field, the system comprising improved means for maintaining a steady flow of solids in the tube, as well as means for preventing clogging of the particulate material in and along the hollow supply boom. The invention will be described in more detail with reference to the appended drawings by way of non-limiting example and in which: FIG. 1A is a perspective view showing a lateral part and the rear part of a conventional vehicle chassis supporting a system carried by vehicle having a dispensing head, a compressor and several hollow and elongated arrows

  the arrows being provided with the means of perfection.

  venturi flow control according to the invention;

  FIG. 1B is a partial perspective view of

  the central or collector portion of the system shown in FIG. 1A;

  Figure 1C is a detail elevational view of

  With the upper part of the plenum chamber used to dispense and deliver compressed air from a source into the individual arrows, the lower portion of the plenum is partially broken away and on a slightly enlarged scale. being torn off; FIG. 2 is a detailed perspective view of the outer portions of the hollow feed arrows according to the invention, showing the point at which the solid feed tube connects to the feed arrow, as well as the point at which the improved venturi means according to the invention are placed; Figure 3 is a sectional view along a diameter of the portion of the device shown in Figure 2; and FIG. 4 is an end view of the part

  of the device illustrated in Figure 1A.

  According to the preferred embodiment of the invention and with particular reference to Figures 1A and 1B, the pneumatic pressurized distribution system, generally designated 10, is mounted on a vehicle frame 11 and comprises a reservoir 12 for retaining a particulate solids feed source to be dispensed by means of the system. A dispensing head 13 is provided for distributing or dividing the solids into particles received or fed from

  of the reservoir 12 in several portions generally

  assessments. Several hollow and elongated feed arrows are intended to receive and deliver or spread the

  solids, the arrows being of predetermined lengths

  and mined and extending laterally outwardly of the vehicle from proximal ends 16 to distal discharge ends 17. A source of compressed air such as a blower 14, for the pneumatic pressurized system, is used to generate a

  flow of compressed air into a room of tranquility

  14A and from this chamber in the proximal ends 16 of each arrow and, finally, through each of the hollow and elongated arrows 15, to an outlet or discharge. These blowers or other sources of compressed air and their mounting in this type of system are of course well known to those skilled in the art and do not need to be described in more detail here. 1A, a cooling device can be used in association with one of the blowers for

  cool the hydraulic fluid used in the system.

  Such a device is illustrated in FIG. 1A, this

  cooler being removed from the view of FIG.

  Several tubular supply elements 18 are also provided, each of these tubular supply elements extending between a chosen outlet of the distribution head 13 and one, chosen, of the supply arrows 15 and connecting them together. . Moreover, as

  this is conventional, the tubular elements 18 of food

  feed each of the aliquots

  in the elongated arrow 15 at a point adjacent to the ex-

  proximal tremity 16 and, finally, feeding to the distal end 17 discharge of the arrow. In addition, as indicated, these spreading structures are known in the art and do not need to be described in more detail here. Such a spreading structure is illustrated in U.S. Patent No. 3,568,937 and a

  another similar system is described in the United States Patent

United States of America N 2 206 876.

  As will be apparent hereinafter, each of the tubular supply members 18 is connected to a selected one of the hollow delivery arrows at a junction point adjacent to the proximal end of one of the arrows and realizes therefore its function of introducing continuously and uniformly an aliquot portion of particulate solids in the flow of compressed air flowing through each of the supply arrows. The introduction of particulate solids into the feed arrows is carried out fundamentally so that the actual introduction of solids into the compressed air flow is improved thereby reducing, if not completely eliminating, any trends in solid particles to accumulate in selected locations and tend to

  to obstruct the flow of the arrow.

  Reference will now be made to FIGS. 2 to 4 which show details of the venturi device provided in each of the hollow supply arrows. In particular and considering FIGS. 2 to 4 of the drawings, the section containing a venturi, generally indicated at 20, of the system comprises an axial segment 21 of one of the feed arrows 15, the end 22 being an adjacent end. at the inner or proximal end of the tube 21. A segment of a tubular supply element 22A is also shown, this segment having been previously indicated as

  one of several tubular elements 18 feeding.

  The tube segment 22A is connected to the boom segment 21

at a junction point 24. -

  Venturi means are provided within the system as generally indicated at 26. The venturi 26 comprises a body portion 27 having an inlet ramp 28, an outlet ramp 29, and a generally rectangular groove portion 30 located between the ramps. A groove portion 30 extends radially inwardly from the inner surface of the boom and generally defines a rope extending through the hollow feed boom, as seen in the views of FIGS. 4. The venturi 26 further operates in cooperation with a blade 32 which is mounted to be generally opposed to the throat portion of the venturi 26. The region between the radially inwardly disposed ridge of the blade 32 and the groove portion 30 defines a gap dimensionally represented at 34 and therefore determines the cross-sectional area available to the airflow in the groove area of the venturi 26. The edge of the blade 32 extends generally rope of the feed boom segment 21, the edge being shown at 35 (FIG. 4) The blade 32 is mounted to form a

  angle converging towards the distal end of the arrow.

  In addition, the inner edge of the blade 32, as indicated at 35, intersects at least a portion of an inwardly directed projection of the supply tubular member 22A into the feed boom segment 21. This arrangement of the blade 32 helps determine the constant width opening through the airflow in the system and

  cause a depression in the tube 22A.

  As shown in the drawings, the blade 32 is normally fixed in place, but it can be made adjustably mountable to generate the maximum vacuum in the tubes 22A during normal operation. As shown, the blade 32

  promotes the establishment of positive directions of flow

  for solids, and the configuration of

  the opening eliminates or substantially reduces any accumu-

  particulate solids in the feed tube, for example within the

tube represented in 21.

  Referring now to FIG.

  shows the arrangement of the individual outputs. This agency

  It is a system in which the individual tubular feed members 18 can be placed in an arrangement in which they are less likely to interfere with each other. Moreover, it is believed that the arrangement as illustrated in FIG.

more uniform airflow.

  In particular, the proximal ends 16 of the arrows are connected in a staggered arrangement at the point of connection to the body of the plenum. Therefore, as illustrated in somewhat exaggerated form in Fig. 1C, the individual tubular feed members 18 can be arranged in more orderly and less concentrated positions. In some cases, it may be desirable to use a baffle and / or stall in the still area to tend to equalize the airflow between the individual arrows. When used, such stalls and / or baffles are usually placed on the arrows that are closest to the inlet of the compressed air from the blower.

  The system according to the invention is particularly

  adapted for use with systems having multiple hollow feed arrows of different lengths. In some cases, it has been found desirable to increase the diameter of the longer arrows used in multiple arrow systems to reduce back pressure in these longer arrows. In addition, the outer sections of the longer arrows may be connected to an enlarged area so that at least one portion of the feed boom has a somewhat increased diameter relative to the shorter arrows. Such a design makes it possible to reduce the back pressure in

  the longer arrows, as well as to establish a

  maximum voltage in the tube 22A connected to the dispensing head. Such an arrangement, associated with the use of a venturi of the type shown at 26, with the blade 32, appeared to produce distribution profiles which are generally more equal to each other than those obtained in the

  Arrow systems previously used.

  It goes without saying that many modifications can be made to the systems described and represented

  without departing from the scope of the invention.

Claims (4)

  A pressurized pneumatic system for substantially uniformly distributing particulate solids on the ground from a system mounted on a self-propelled vehicle (11) and comprising a reservoir (12) containing a solids supply source in particles to be dispensed, a dispensing head (13) for metering and distributing particulate solids from said source into a plurality of generally aliquot portions, a plurality of elongate and hollow delivery arrows (15) having predetermined and different lengths , extending laterally out of the vehicle from a proximal end (16) to a distal discharge end (17), a source (14) of compressed air for generating a flow of compressed air through the hollow and elongated arrows, several tubular elements (18)   each extending between the dispensing head and   and one, selected, supply arrows, for bringing each of said aliquots from the proximal end to the distal discharge end of an arrow, and an adjacent junction point (24). at the proximal end of each of the hollow and elongated arrows for introducing an aliquot portion of the particulate solids into the flow of compressed air passing through each of said feed arrows, the system being characterized in that it comprises means venturi (26) mounted within each hollow supply arrow, between   the junction point and the proximal end, immediately   upstream of said junction point, the venturi means including a flow wedge (27) defining an inlet ramp (28), an exit ramp (29) and a groove portion (30) between the air intake ramps inlet and outlet, said groove portion extending radially inwardly and generally along a rope through the hollow feedthrough, the venturi means further comprising a blade (32) which cooperates with the wedge and which is mounted so as to be generally opposed to the groove portion of the venturi means, said blade extending generally in a rope which traverses the hollow intake spigot and extending radially inwardly the hollow arrow at an angle converging towards the distal end of the arrow, the inner edge (35)   of the blade intersecting at least a portion of a projection   tubular supply element from its   intersection with said hollow supply arrow, the   being such that the venturi means generates a partial vacuum in the hollow spigot of feed in the vicinity   immediately and along the junction point.   2. The system of claim 1, wherein   characterized in that the throat portion of the venturi flow wedge is a line defined at the intersection of the ramp entrance and exit ramp.   3. System according to claim 1, characterized   characterized in that the blade is adjustably mounted   radially with respect to the feed arrow.   A pneumatic pressurized system for substantially uniform distribution of particulate solids on the ground from a system mounted on a self-propelled vehicle (11) and comprising a reservoir (12) having a solids supply source thereon. particles to be dispensed, a dispensing head (13) for metering and distributing particulate solids from the source into a plurality of generally aliquot portions, a plurality of hollow arrows   and elongated delivery means (15) having predetermined lengths   and later, extending laterally outwardly of the vehicle, from a proximal end (16) to a distal discharge end (17), a source (14) of compressed air for generating a flow of compressed air in the hollow and elongated arrows,   a plurality of tubular elements (18) for feeding   each between the dispensing head and a selected one of the delivery arrows, for bringing each of the aliquots of the proximal end to the distal discharge end of an arrow, and a point (24) of junction adjacent to the proximal end of each of the hollow and elongated arrows to introduce a portion   aliquot of particulate solids in the   compressed air passing through each of the feed arrows, the system being characterized in that it comprises a means (14A) with a plenum chamber arranged between the source of compressed air and the proximal end of each of the arrows to to receive a load of compressed air and to distribute a portion of this load to   each of the arrows, said chamber means of tranquillization   having a face in which are formed a plurality of orifices each connected to the proximal end of one of the arrows, said orifices being arranged along the face of the plenum chamber means in an axially staggered arrangement, compared to others.