Device and method for dispensing a liquid product that is to be sprayed onto a surface

Patent metadata

Field	Value
Publication number	US-9445540-B2
Application number	US-201113817764-A
Country	US
Kind code	B2
Filing date	Jul 29, 2011
Priority date	Aug 18, 2010
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

The device according to the invention comprises a bar that includes several consecutive ducts with at least one inlet connected to a source of the liquid product and outlets communicating with nozzles. The device further comprises several sensors for measuring a physical property making it possible to determine a pressure difference between ducts or a pressure in one respective duct, several members designed to vary the pressures inside respective ducts, as well as at least one control unit estimating the pressure differences between ducts and driving the members to reduce those pressure differences or equalize those pressures. This device thus limits the pressure differences, and therefore flow differences, of the liquid product between the nozzles, in particular between the ends of very long bars moving over significant bankings.

First claim

The invention claimed is:

1. A device for dispensing a liquid product to be sprayed over a surface such as an agricultural field, the device comprising:
a bar for spraying the liquid product, the bar including several consecutive ducts, each duct forming a longitudinal segment of the bar and having:
at least one inlet port designed to be in fluid communication with at least one liquid product source; and
at least one outlet port adapted to be in fluid communication with at least one nozzle,
wherein the device further comprises:
several sensors linked to respective ducts, each sensor being configured for measuring a physical property making it possible to determine a pressure difference between two respective ducts or a physical property making it possible to determine respective pressures inside at least two ducts;
several members designed to vary the pressures inside respective ducts, each member being in fluid communication with at least one inlet port; and
at least one control unit interconnected with the sensors so as to estimate the pressure differences between at least two ducts, said control unit being interconnected with the members so as to drive them to reduce said pressure differences or equalize said pressures.

2. The device according to claim 1 , wherein the control unit is designed to drive the members so as to limit said pressure differences to less than 10%.

3. The device according to claim 1 , wherein the sensors comprise pressure sensors attached on respective ducts.

4. The device according to claim 1 , wherein the sensors comprise at least one inclinometer.

5. The device according to claim 1 , wherein the members comprise members for restricting the flow of the liquid product, such as needle regulators, sliding gate valves, ice sluices or proportional solenoid valves, or hose clamps.

6. The device according to claim 5 , wherein at least one flow restricting member includes two discs coaxially juxtaposed, each disc being pierced with an orifice that is asymmetrical relative to the axis of the discs, the discs being rotatable around their shared axis under the action of a driving member, for example an electric motor.

7. The device according to claim 1 , wherein each duct is linked to a sensor and each inlet port is in fluid communication with a member.

8. The device according to claim 7 , wherein the bar further includes connecting conduits arranged such that two consecutive ducts are connected by a respective connecting duct and such that the connecting conduits form at least one bar portion equipped with several ducts connected in series, the bar including one or more of said bar portions arranged in parallel, and wherein at least one member is arranged between the ducts connected in series.

9. The device according to claim 8 , further comprising two supply conduits respectively coupled to the two ducts arranged at each end of the bar or of a bar portion, in that the bar or each bar portion also includes two members or two cutoff valves, each member or cutoff valve being arranged to selectively allow a flow of liquid product in a respective supply conduit or to create a predetermined pressure drop.

10. The device according to claim 1 , further comprising several supply conduits designed to be connected in parallel to at least one liquid product source, each supply conduit being in fluid communication with at least one respective member, the member being coupled in the upstream region of a respective supply conduit.

11. The device according to claim 9 , wherein at least two supply conduits are coupled to a same member.

12. The device according to claim 1 , wherein at least one from among the set of sensors and the set of members forms a multiplexed network interconnected by a bus.

13. The device according to claim 1 , wherein each sensor and each member are incorporated into a single and same component, the set of components being interconnected between them by a same cable forming a multiplexed network and providing electricity.

14. The device according to claim 13 , wherein said member further incorporates means for cutting the arrival of fluid into the associated duct.

15. A method for dispensing a liquid product to be sprayed over a surface such as an agricultural field, the device comprising a bar for spraying the liquid product, the bar having several consecutive ducts, each duct forming a longitudinal segment of the bar and having:
at least one inlet port designed to be in fluid communication with at least one liquid product source; and
at least one outlet port suitable for being in fluid communication with at least one nozzle,
wherein the method comprises the following steps:
measuring a physical property making it possible to determine respective pressures inside at least two ducts using several sensors linked to respective ducts;
estimating the pressure differences between at least two ducts by means of a control unit, which is centralized or specific to each sensor, and which is interconnected with the sensors; and
varying the pressures inside the respective ducts using members that are respectively in fluid communication with at least one of said inlet ports and which are driven by the control unit as a function of said pressure differences.

16. The method according to claim 15 , further comprising the following steps:
checking whether a pressure at a duct is above a predetermined threshold;
if said pressure is above the predetermined threshold, driving the member corresponding to said duct normally; and
if said pressure is below the predetermined threshold, keeping the member corresponding to said duct in its prior state and with a maximum flow section.

17. The method according to claim 15 , further comprising the following steps:
implementing the device wherein the sensors comprise pressure sensors attached on respective ducts,
associating the device with a pressure or flow regulating unit, designed to modulate the total flow rate of the sprayed liquid product as a function of the forward speed of the device on the surface;
calculating, regularly and using the control unit, the gap between an average value of the pressure measured by the sensors and the pressure caused by said regulating unit; and
driving each member so as to keep said gap below a predetermined value.

18. The method according to claim 15 , wherein each member is driven with an opening speed greater than the closure speed.

19. The method according to claim 15 , further comprising the following step:
if the physical property measured by a sensor establishes that a pressure inside a target duct differs abnormally and simultaneously from the pressures inside two adjacent ducts, using the control unit to generate a signal identifying the target duct so as to inform an operator that a clog may have occurred in or near the target duct, for example at a filter and/or a nozzle.

Assignees

• Ballu Patrick Jean Marie
• Exel Ind

Inventors

• Ballu Patrick Jean Marie

Classifications

• A01M7/0089

  Regulating or controlling systems (the delivery being related to the movement of a vehicle B05B9/06) · CPC title

• A01C23/047

  Spraying of liquid fertilisers · CPC title

• B05B12/006

  Pressure or flow rate sensors · CPC title

• A01M7/0042 Primary

  Field sprayers, e.g. self-propelled, drawn or tractor-mounted · CPC title

• A01C23/007 Primary

  Metering or regulating systems · CPC title