GB2327231A

GB2327231A - Vehicle with weed/foliage killing facility

Info

Publication number: GB2327231A
Application number: GB9813969A
Authority: GB
Inventors: Paul David Souter
Original assignee: AQUA HYDRAULICS Ltd
Current assignee: AQUA HYDRAULICS Ltd
Priority date: 1997-07-11
Filing date: 1998-06-30
Publication date: 1999-01-20
Also published as: GB9813969D0

Abstract

A railway or roadway maintenance vehicle (1) for the distribution of phytotoxic agents comprises at least one spray nozzle (10, 10A - 10F) at one or both lateral sides of the vehicle and so oriented as to be capable of discharging a spray both laterally and downwardly of the vehicle (1), means to supply a mix of high pressure water and a phytotoxic agent to the or each spray nozzle (10,10A - 10F) and means to displace the vehicle at a relatively high speed.

Description

TITLE OF THE INVENTION Vehicle with weed/foliage killing facility BACKGROUND OF THE INVENTION (i) Field of the Invention The invention relates to a railway or roadway maintenance vehicle for the distribution of phytotoxic agents to prevent or discourage the encroachment of foliage etc in the vicinity of rail tracks or roadways.

(ii) Description of the Prior Art In the railway industry, the application of defoliants or weed killers or the physical removal of weeks etc by scything cutting or working a ballast bed has largely been undertaken manually which is slow, costly, ineffective and generally produces only short term results, although automation with deployable lateral spray bars is proposed in DE 4132637 and DE 3935719. Also existing agrochemical and weed spray systems, operate at no more than 10 bar pressure. The majority of applications are carried out at low speed either by hand or from a slow moving vehicle such as a tractor, and the usual method of application is to pre-mix the chemical with water before pumping into the nozzle system. When these techniques are adapted to control weeds and foliage on the railway or road a large vehicle is required to provide sufficient range. As the vehicle speed increases the effect of slipsteam carry the low pressure sprays away. Uncontrollable and higher volumes of non-treated water have to be used to control this thereby reducing useful range further.

In roadway maintenance, automated treatment by vehicles has been proposed, but proposals have frequently incorporated spray bars, used in conjunction with rotary brushes, which spray bars may be fixed or deployable which can be damaged or can cause damage to obstacles in their path.

For urban use, street or pavement cleansing vehicles are known with a combination of low pressure water spray nozzles and rotary brushes, e.g. US 5097560.

OBJECT OF THE INVENTION A basic object of the invention is to provide a vehicle whereby not only is manual weed killing etc eliminated, but the vehicle is capable of controlled and hence accurate deposit of phytotoxic agents without spray bars and is capable of operating at relative high speeds, e.g. < 40 mph.

SUMMARY OF THE INVENTION According to the present invention there is provided a railway or roadway maintenance vehicle for the distribution of phytotoxic agents comprising (i) at least one spray nozzle at one or both lateral sides of the vehicle and so oriented as to be capable of discharging a spray both laterally and downwardly of the vehicle; (ii) means to supply high pressure water; (iii) means to inject phytotoxic agent at high pressure into, or upsteam of, each spray nozzle; (iv) means to operate each nozzle collectively or independently; and (v) means to displace the vehicle at a relatively high speed.

The invention thus mechanises weed killing and foliage encroachment without the hazards presented by projecting or deployed spray bars, as the (lateral) spray nozzle(s) can be mounted within the cross-sectional envelope of the vehicle with no mechanical protrusions.

Furthermore, operational speeds of up to 40 mph is approaching normal rail speed for freight traffic, and consequently for railway use, the vehicle in accordance with the invention may be operated during normal working hours, scheduled amongst normal rail traffic. Similarly, considering roadway use, elimination of labour intensive, slow speed weed killing and defoliating operations results in minimal disruption to traffic flow, lane closure etc. Also, the localised injection of the phytotoxic agent avoids pre-mixing large volumes, with attendant spillage, storage and disposal problems. Furthermore, the vehicle in accordance with the invention permits the accurate control of the dosing rate of the agent, and the zone of deposit of the mix. In addition, the use of a high pressure mix provides more energy in the water droplets, enabling use in high speed slipstreams with the minimum of spray drift.

The means to supply high pressure water may comprise a positive displacement water pump. The means to inject the phytotoxic agent may comprise at least one positive displacement dosing pump. Injection of the phytotoxic agent may be effected downsteam of a valve, controlling the water supply. The water pump(s) may supply water at circa 100 bar, whilst the dosing pump may inject the phytotoxic agent at circa 100 bar.

The vehicle could be a trailer type vehicle or wagon to be towed behind a locomotive or road tractor, or the vehicle could be self-propelled.

In a rail vehicle embodiment, the vehicle is also preferably provided at its underside with at least one spray nozzle, and possibly at least one set of six or more transversely spaced-apart spray nozzles, to emit a spray(s) of the mix of high pressure water and phytotoxic agents to the zone between the running rails. Further, a rail vehicle embodiment is preferably provided with (lateral) spray nozzles at both sides of the vehicle.

Preferably, the vehicle comprises a diesel driven pump unit e.g. of 250 kW, capable of delivering water from an on-board, large capacity water tank, to the nozzle(s) at pressures of up to 1000 bar. This results in the lateral spray(s) being capable of effective spraying over a distance of up to 1.5m.

Tests have shown that satisfactory, controlled spraying can be achieved, with the phytotoxic mix deposited over the required lateral zone at pressures up to 250 bar, with no adverse effect from wind or slip stream that would, with low pressure sprays, result in a cloud of vaporised mix dissipated into the general atmosphere to fall in an uncontrolled, random pattern rather than being effectively deposited on track sides etc, foliage.

Preferably, the delivery pressure of the mix is adjustable to mitigate the slip stream effect of the moving vehicle, and the (lateral) nozzle(s) may be supplied at a higher pressure than the underside nozzles.

The dosing pump(s) may be driven through an adjustable speed drive which once set always runs at the same speed relative to the water pump(s) thus ensuring accurate dosing.

Preferably, for railway use, the vehicle takes the form of a double tram traction unit, with one tram carrying the pump unit in a sound proof enclosure and the other carrying a large capacity water tank and other peripheral equipment. The pump and tanker units are permanently coupled and the double traction unit is capable of travelling in either direction. Control of the pump and accessories is exercised remotely from either cab of the tractor.

The diesel driven pump pumps fresh water from the supply tanker, with liquid, weed killing agents metered into the high pressure delivery prior to jetting. Clearly storage tanks for the weed killer and metering pumps need to be provided.

Preferably, control means is provided to control the pump speed, and hence water flow, in relation to the linear speed of the vehicle to ensure adequate cover at full speed and prevent over kill at slow speed.

Preferably, in a rail vehicle embodiment, a set of six transversely spaced-apart nozzles is provided between the rail. These nozzles are arranged to provide a divergent spray pattem such that cumulatively, the or each set of six spray nozzles ensure that the full width between the rails is treated.

Preferably, each lateral spray nozzle comprises a set of up to six individual spray nozzles arranged to produce divergent sprays of the pressurised mix of phytotoxic agent and water and so angled that, cumulatively, all six sprays ensure ground cover and hence treatment from the outside of the adjacent rail typically up to 1.5m from the adjacent rail.

As illustrated in Figure 1, a self-propelled railway vehicle 1 incorporates an industrystandard traction unit, not detailed, and in accordance with the invention comprises a double tram traction unit, being a first tram 2 carrying a diesel driven pump unitti a sound-proof enclosure 3 coupled to a second tram 4 carrying a plurality of water tanks 5. At the terminal end of each tram 2 and 4 is a control cab 6 whereby the vehicle 1 may be driven in either direction along rails 7.

In Figure 2 is diagrammatically shown a cross-section of approximately half of the vehicle 1. Between the rails 7 are located a set of six spray nozzles 8 laterally spaced, e.g. 250 mm apart across the vehicle and supplied with a metered mix of water and phytotoxic agent from the pump unit, with the pump speed and hence output being related to linear speed to ensure economic use of both phytotoxic agent, and energy. Each spray nozzle 8 is arranged to provide a divergent, e.g. conical spray pattem 9 extending transversely over e.g. 250 mm, such that cumulatively, the six spray nozzles ensure that the full width of 1435 mm between the rails 7, and a little beyond of 1500 mm, is treated. One or more sets of six nozzles 8 may be provided on one, or both trams 2 and/or 4.

Outside the rails 7, the trams 2 and 4 are provided at each lateral side with at least one lateral spray nozzle 10, and preferably, each nozzle 10 comprises an array of up to six individual nozzles 10A to 10F, all arranged, and angled, to produce divergent spray patterns 11 extending laterally and/or downardly of a pressurised mix of phytotoxic agent and water respectively of 420 mm, 280 mm, 200 mm, 170 mm, 170 mm and 260 mm, so that cumulatively, all six sprays ensure ground cover from the outside of each rail 7, typically of < 1.5m from the adjacent rail 7.

As a basic object of the provision of the lateral spray nozzle 10 is to dispense with the need for spray bars, of the fixed position or of the deployable kind, resulting in the need to spray the mix from at least some of the individual nozzles 10A to 10F at a higher pressure, by standard engineering means, than the nozzles 8.

The result is a vehicle 1 that can be rail operated, at linear speeds of up to 40 mph, thereby causing minimal, if any, disruption to scheduled traffic, without the potential hazard of spray bars.

Claims

CLAIMS:

1. A railway or roadway maintenance vehicle for the distribution of phytotoxic agents comprising (i) at least one spray nozzle at one or both lateral sides of the vehicle and so oriented as to be capable of discharging a spray both laterally and downwardly of the vehicle; (ii) means to supply high pressure water; (iii) means to inject phytotoxic agent at high pressure into, or upsteam of, each spray nozzle; (iv) means to operate each nozzle collectively or independently; and (v) means to displace the vehicle at a relatively high speed.

2. A vehicle as claimed in Claim 1, wherein the means to supply high pressure water comprises a positive displacement water pump.

3. A vehicle as claimed in Claim 1 or Claim 2, wherein the means to inject the phytotoxic agent comprises at least one positive displacement dosing pump.

4. A vehicle as claimed in any preceding Claim, wherein injection of the phytotoxic agent is effected downsteam of a valve, controlling the water supply.

5. A vehicle as claimed in Claim 2, and any Claim appendant thereto, wherein the water pump(s) supplies water at circa 100 bar.

6. A vehicle as claimed in Claim 3, and any Claim appendant thereto, wherein the dosing pump injects the phytotoxic agent at circa 100 bar.

7. A vehicle as claimed in any preceding Claim, wherein the vehicle is a trailer type vehicle or wagon to be towed behind a locomotive.

8. A vehicle as claimed in any one of Claims 1 to 6, wherein the vehicle is selfpropelled.

9. A vehicle as claimed in any preceding Claim, for railway use, provided at its underside with at least one spray nozzle and preferably at least one set of transversely spacedapart spray nozzles to emit a spray(s) of the mix of high pressure water and phytotoxic agents to the zone between the running rails.

10. A vehicle as claimed in Claim 9, wherein the or each set of underside spray nozzles is arrange on a spray bar.

11. A vehicle as claimed in Claim 9, provided with lateral spray nozzles at both sides of the vehicle.

12. A vehicle as claimed in any preceding Claim, comprising a diesel driven pump unit, e.g. of 250 kW, capable of delivering water from an on-board, large capacity water tank, to the nozzle(s) at pressures of up to 1000 bar, but preferably circa 100 bar.

13. A vehicle as claimed in Claim 11, or Claim 12 when appended to Claim 11, wherein the lateral spray nozzles are supplied at a higher pressure than the underside nozzles.

14. A vehicle as claimed in any preceding Claim, for railway use, comprising a double tram traction unit, with one tram carrying the pump unit in a sound-proof enclosure and the other carrying a large capacity water tank and other peripheral equipment.

15. A vehicle as claimed in Claim 14, wherein the pump and tank units are permanently coupled and the double traction unit is capable of travelling in either direction.

16. A vehicle as claimed in Claim 14 or Claim 15, wherein control of the pump and accessories is exercised remotely from either cab of the tractor.

17. A vehicle as claimed in Claim 12, and any Claim appendant thereto, wherein the pump unit pumps fresh water from the supply tank, with the phytotoxic agent liquid and metered into the high pressure supply at, or upsteam of, the spray nozzles.

18. A vehicle as claimed in Claim 3, and any Claim appendant thereto, wherein the dosing pump(s) is driven through an adjustable speed drive which, once set, always runs at the same speed as the water pump(s).

19. A vehicle as claimed in any preceding Claim, comprising storage tanks for liquid phytotoxic agent.

20. A vehicle as claimed in Claim 12, and any Claim appendant thereto, wherein control means is provided to control the water pump speed, and hence water flow, in relation to the linear speed of the vehicle.

21. A vehicle as claimed in Claim 9, and any Claim appendant thereto, wherein a set of six transversely spaced-apart underside nozzles is provided between the rails.

22. A vehicle as claimed in Claim 21, wherein the or each set of six underside nozzles is so arranged to provide a divergent spray pattern such that cumulatively, the or each set of six underside nozzles ensure that the full width between the rails is treated.

23. A vehicle as claimed in any preceding Claim, wherein each lateral nozzle comprises a set of up to six individual nozzles.

24. A vehicle as claimed in Claim 23, wherein the individual lateral nozzles are so arranged to produce divergent sprays of the pressurised mix of phytotoxic agent and water and so angled that, cumulatively, all six nozzles ensure ground cover and hence treatment from the outside of the adjacent rail typically up to 1.5m from the adjacent rail.

25. A railway or roadway maintenance vehicle for the distribution of phytotoxic agent, substantially as hereinbefore described with reference to the accompanying drawings.