NL1018458C2 - Weed killing method, comprises spraying hot water onto weeds, followed by deposition of insulating foam layer - Google Patents

Abstract

Water is sprayed onto the weeds at a relatively high temperature, preferably greater than 95 deg.C, and an insulating layer of foam is deposited on the weeds which have been sprayed. An independent claim is also included for the weed removal device (1) for carrying out this method, comprising a water heater (5), a pump (3) for forcing the heated water out of a first nozzle (35), a foam forming device (64) and a second nozzle (44) for applying the foam.

Description

Title: Method and device for controlling vegetation.

The invention relates to a method for controlling vegetation. Such a method is known from practice.

In this method, hot foam is formed which is forcefully sprayed onto vegetation from a nozzle. Just before leaving the nozzle, this foam has a temperature that is between 75 ° C and 100 ° C.

It has been found that in such a method insufficient control of the vegetation occurs. Without wishing to be bound by any theory, this appears to be the result of the relatively rapid cooling of the foam, at least the vegetation treated with it. It is therefore an object of the invention to provide a method for controlling vegetation with a better, or at least longer-lasting, effect. To that end, a method according to the invention is characterized by the features of claim 1.

In a method according to the invention, the vegetation is sprayed substantially directly with the hot water, so that a powerful controlling action is obtained. Furthermore, the vegetation, at least after being treated with the water, is covered by a foam layer. This foam layer has an insulating effect, as a result of which the vegetation is kept warm for longer and a longer-lasting effect appears to be obtained. A better controlling action is thereby obtained than with the existing, known method.

A further advantage of a method according to the invention is that the heat disappears more gradually. Vapor formation is therefore largely prevented. Moreover, splashing of the water can be prevented at least for the greater part with the foam layer, as a result of which pollution of the environment can at least partially be prevented.

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In a further advantageous embodiment, a method according to the invention is characterized in that the hot water is applied through a first nozzle, while foam is applied through a second nozzle for forming the foam layer, which nozzles are moved through or over the vegetation. With this, the water can be applied directly to or in the vegetation in a particularly simple manner, while the foam layer can be provided over it.

The water is preferably sprayed with relatively high water pressure, while the foam layer is applied at relatively low pressure.

With this the foam layer can be positioned well, while the pressure of the water can be used for a particularly effective control of the vegetation.

In a method according to the present invention, use is preferably made of means for heating the water, which are easily displaceable and operable. A particularly suitable embodiment of such a device is described, for example, in applicant's non-prepublished Dutch patent application NL 1015139, which is incorporated herein by reference.

The invention furthermore relates to a device for controlling vegetation, characterized by the features of claim 9.

With such a device, vegetation can be controlled with the aid of heated water, wherein an insulating foam layer can be applied to retain the heat in the vegetation and / or the soil for a relatively long time. The device is preferably designed in such a way that the water is heated to near or above atmospheric boiling point. The first and second nozzles are herein preferably placed at some distance from each other, preferably such that in the normal direction of movement of the nozzles the first nozzle extends slightly below the second nozzle. This means that during use, water will be sprayed directly onto the vegetation during use, virtually unhindered by foam, after which a covering, insulating foam layer will be applied almost immediately over the heated and already largely contested vegetation.

In an apparatus according to the invention, blowing means are preferably used which are in fluid communication with the second nozzle. Water, for example a small part of the heated water, is mixed, substantially pressureless with foaming agent, after which it is forced through the second nozzle with the blower. Foam-forming means, such as bubbles for blowing bubbles, for example a perforated plate or the like, are provided in the second nozzle. A foam layer can hereby be obtained simply and effectively. When a device according to the invention is used, a foam layer is preferably formed with a thickness between a few millimeters and a few centimeters, which foam layer is preferably relatively compact.

Further advantageous embodiments of a method and device according to the invention are described in the further subclaims. To clarify the invention, exemplary embodiments of a method and device according to the invention will be further elucidated with reference to the drawing. In the drawing: Fig. 1 schematically shows a device according to the present invention; and Fig. 2 schematically shows a spraying device in side view, with first and second spray nozzle with a water jet and foam layer emerging therefrom.

Figure 1 shows diagrammatically a device which is provided with a water supply tank 2, a high-pressure pump 3 driven by a motor 4, a flow heater 5 and a spraying device 6, which are mutually connected via a first, second 30 and third line 7, 8, 9.

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For the supply of water, the storage tank 2 can be connected to supply means 10, in the form of a low-pressure hose 11 and a supply filter 12. The storage tank 2 is connected to a high-pressure pump 3, with which the water from use the storage tank 2 in the direction of the 5 flow heater 5 is pumped. To this end, pump 3 is driven via transmission means 25 by combustion engine 4.

Motor 4 is provided with a throttle or accelerator pedal 15, with which the speed of the motor can be continuously adjusted by a user. This speed, together with the high-pressure pump 3 connected thereto, determines the volume of the water flow that is pumped from storage tank 2 towards the flow heater 5 via a first and second line 7, 8.

The flow heater 5 in Figure 1 is designed as a high-pressure burner coil 24. The coil 24 is heated by an oil-fired burner installation 30. Of course, the burner installation 30 can also be a gas-fired or other burner installation. The water flowing through the spiral 24 is hereby heated to a temperature ranging from just below to well above the boiling point, for example between 95 and 140 degrees Celsius. The temperature can be adjusted to a desired value by means of a thermostat control 31. In this exemplary embodiment, the thermostat control 31 comprises a first and a second thermostat 32, 33, as well as a safety thermostat 34, the function of which will be discussed below. The first thermostat 32 controls the temperature below the boiling point, in particular up to 98 degrees Celsius. The second thermostat 33 controls the temperature from 98 degrees to approximately 140 degrees Celsius. The user can switch on one of the two thermostats 32, 33 by means of a selector switch and use the device for hot water or boiling water as desired.

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The flow heater 5 is connected via a high pressure line 9 to a spraying device 6, which will be described in more detail below. With spraying device 6 the heated water is sprayed under high pressure on vegetation to be controlled. To this end, the spraying device 6 is provided with first 5 nozzles 35, for example high-pressure flat jet nozzles. Such a flat jet nozzle 35 is known, for example, from patent EP 0862950. Such flat jet nozzles have such an outflow opening 36 that the exiting jet has a divergent course, with a relatively small apex angle α and thickness d. For example, the apex angle <x is preferably between 10 and 10 degrees and the thickness d of the radius is preferably smaller than a few millimeters. Thanks to the special outflow opening 36, the boiling water emerging from the nozzle does not atomize into steam, but is held together in a flat stab or putty knife-shaped jet. Other nozzles can of course also be used, wherein steam formation is preferably prevented.

The device furthermore comprises various security systems. For example, storage tank 2 is equipped with means to keep the water level within certain limits. The maximum water level is maintained with the aid of a float valve 16 and an overflow facility 17. The minimum water level is maintained by a low water protection 14, which, when the water level in the storage tank 2 threatens to become too low, adjusts the speed of motor 4 so that the water flow pumped from storage tank 2 decreases.

Furthermore, pressure protection means 18 are provided between the high-pressure pump 3 and the flow heater 5, comprising a manometer 19, a pressure control device 20, a pressure switch 21, a flow switch 22 and a safety valve 23. The pressure control device 20 controls the pressure in the second line 8 by more or more to return less water via a fourth line 26 to the storage tank 2, so that the pressure does not become inadmissibly high. Safety valve 23 provides additional protection in the event that said pressure, despite pressure regulating device 20, nevertheless exceeds a preselected maximum value, for example 350 Bar. Safety valve 23 will open in that case, as a result of which the water will spray out of the device.

This causes a decrease in pressure and moreover gives a clear signal to the user that the pressure control device 20 is functioning insufficiently. The switches 21, 22 are intended as protection for the burner installation 30. This does not come into operation until both switches 21, 22 are switched on. Pressure switch 21 only switches on after a minimum pressure has been built up in the system, for example 5 or 25 Bar, while flow switch 22 switches on when a minimum flow through line 8 is detected. The switches 21, 22 thus ensure that, with a burner installation 30 in operation, a minimum flow flows through the flow heater 5 and a minimum pressure prevails therein, so that the risk of the installation overheating is limited.

Furthermore, a safety thermostat 34 is provided, which switches off the combustion installation 30 when the water in the flow heater 5 flows for any reason in the wrong direction, i.e. flows back to the pump 3. This again avoids the undesirable situation that the combustion installation 20 an empty or malfunctioning flow heater 5 would (over) heat.

The device furthermore comprises a blower 40, for example driven by the motor 4, at least by a generator driven by it. The blower 40 is connected on the blower side to a foam supply hose 42 which is connected to a second nozzle 44 of the spraying device 6. A chemical storage vessel 46 connects to the foam supply hose 42 via a supply hose 48 with supply valve 50. In addition, an intermediate line 52 is provided between the pressure line 9 and the foam supply hose 42, in which a tap with pressure control 54 is included for supplying heated water at the foam supply hose 42 at relatively low pressure. During use, with the blower 40, the water supplied through the intermediate line 52 can be blown through the foam supply hose 42, foaming agent being supplied from the chemical storage vessel 46. This mixture is driven through the foam supply hose 42 to the second nozzle 44 and leaves the second spray mount 44 as foam, as will be explained in more detail below.

In the embodiment shown, the spraying device 6 is shown diagrammatically as a mobile device provided with wheels 13 with a body 56 on which the first nozzles 35 are placed relatively low and, slightly above it, viewed in the direction of travel R behind the first nozzles 35, the second nozzle 44. In the embodiment shown, the second nozzle 44 is of relatively wide design, in particular wider than the first nozzles 35. However, other second nozzles 44 can also be provided, for example a row of smaller ones. The spraying device 6 is provided with a drawbar 58 with which it can be driven through, at least over vegetation, as schematically shown in figure 2.

A device according to Figure 1 can be used as follows. The supply tank 2 is connected with the supply means 10 to a water supply network or reservoir. This tap water, to which no further chemicals need be, but which can be added, is introduced via supply means 10 into storage tank 2 and from there is pumped via the first line 7 with high-pressure pump 3 and the second line 8 to the flow heater 5. The operating pressure in the device can be adjusted by adjusting the speed of engine 4, with the aid of a throttle lever or accelerator pedal 15. Incidentally, this can also be provided with wireless remote control means. The flow rate pumped by the high-pressure pump 3, for example 5 to 20 liters per minute, more particularly 7 to 12 liters per minute, will increase or decrease due to the speed adjustment. This flow rate in combination with the outflow opening of the first nozzles 35 essentially determines the operating pressure prevailing within the device as well as the water pressure upon leaving the nozzle 1018458 8. Thanks to the stepless adjustment possibility of the engine speed, any desired operating pressure or water pressure can be achieved. within the chosen minimum and maximum limits. At maximum speed of the motor 4, these pressures can amount to, for example, 350 Bar. In practice, lower speeds will be set, as a result of which the working and water pressure will be between, for example, 25 and 200 Bar. The water under this high pressure is heated during the flow of the coil 24 to a temperature between 95 degrees and 140 degrees Celsius. This temperature can be regulated independently of the operating pressure and is set using the previously described thermostats 32, 33, the choice of thermostat 32 leading to a hot water temperature below boiling point, while the choice of thermostat 33 leading to water with a temperature above the boiling point.

After passing through the flow heater 5, the water is led via the third line 9 to the spraying device 6, where the boiling water leaves the nozzles 35 under high pressure.

The spraying device 6 is driven, preferably together with the entire device 1, over a surface 60 to be treated. Vegetation 62 grows on this surface and must be controlled. With the aid of the foam forming means 64, comprising at least the blower 40, the chemical storage vessel 46, the foam supply hose 42, the second nozzle 44 and the associated pipes, foam is formed which is transferred via the second nozzle 44 over the vegetation 62 as a insulating foam layer 66. This foam layer is at least thermally insulating, so that the hot water 68 which has left the first nozzles 35 under high pressure does not cool down too quickly, nor does the treated vegetation 62. As a result, the action of the hot water 68 significantly increased, or at least extended. Optionally, the foam 66 may also contain chemicals, preferably biodegradable pesticides. The foam 66 itself is preferably also biodegradable. Splashing of water and thus pollution of the environment is at least partially prevented by the foam.

For the purpose of foaming, a perforated plate 70 is provided in the second nozzle 44, part of which is shown in Figure 2A. Provided in this plate 70 is a pattern of openings 72 through which the water with the chemicals is blown through the blower 40. Bubbles are hereby blown to obtain the desired foaming. The diameter of these openings 72 is preferably relatively small, for example between 4 and 20 millimeters, preferably approximately between 8 and 10 millimeters, for obtaining a nice, compact foam. However, any size and any desired pattern of openings can of course be used, depending on, for example, the foam-forming means used, the air pressure used and the desired compactness of the foam.

A device according to the invention can be applied in addition to crop control for removing, for example, paint, graffiti and chewing gum from, in particular, floors, without thereby damaging the substrate, whereby work can also be carried out without foam. The good cleaning effect is partly based on the combination of the high temperature of the water, the shape and power of the water jet. The method is suitable for use with normal tap water. Additional additives in the form of cleaning agents or other chemicals are not necessary, so that a very environmentally friendly method of cleaning is obtained.

The device can be placed on a trailer for transport and use.

The invention is not limited to the exemplary embodiments shown in the description and the drawing. Many variations thereof are possible within the scope of the invention as set forth in the claims.

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The high-pressure pump in the above figure can for instance be a rotary piston pump, a plunger pump, vane pump or a pump that is otherwise suitable for high pressures. The drive motor 4, which in the above embodiment is designed as a diesel oil engine, can for instance also be a gas engine, whereby it can be combined with a gas tank for the mobility of the device or be driven otherwise, for example electrically. The flow heater may also have any shape known from practice instead of as a spiral. Other foam-forming means can also be used, for example a lattice work of stirring means and the like. The first and second nozzles can be designed differently and, moreover, can be positioned with respect to each other in a different way. The spraying device 6 can also be of a different design, for instance portable, wherein the first and second spraying nozzle (s) can be arranged on one carrier.

These and comparable variations are understood to fall within the scope of the invention as defined by the claims.

Claims (15)

A method for controlling vegetation, wherein water of relatively high temperature, in particular more than 95 ° C, is sprayed on the vegetation, wherein an insulating foam layer is applied over at least the vegetation sprayed with the water. A method according to claim 1, wherein the hot water is applied through a first nozzle while foam is applied through a second nozzle to form the foam layer, the two nozzles being moved over or through the vegetation. 3. Method as claimed in claim 1 or 2, wherein at least the water 10 is sprayed with relatively high water pressure, while the foam layer is applied at relatively low pressure relative to the water pressure. A method according to any one of the preceding claims, wherein the water is forced through a high-pressure line by means of a pump and is heated therein. 5. Method as claimed in any of the foregoing claims, wherein a part of the hot water is used for forming, at least heating the foam layer. 6. A method according to any one of the preceding claims, wherein the water under a pressure of more than 5 * 105 N / m2, in particular more than 20 * 105 N / m2, more in particular between 25 * 105 N / m2 and 350 * 105 N / m2 and preferably between 25 * 105 N / m2 and 250 * 105 N / m2. A method according to any one of the preceding claims, wherein a device according to NL 1015139 is used for heating and supplying the water. A method according to any one of the preceding claims, wherein water with foaming agent is fed to a nozzle and with the aid of air, foam is formed in or near said nozzle. 1 01 8458 An apparatus for controlling vegetation, comprising: heating means for water and pumping means for forcing heated water through a first nozzle; and foam-forming means for dispensing foam through a second nozzle 5. Device as claimed in claim 9, wherein the heating means are adapted for heating the water to near or above the boiling point. 11. Device as claimed in claim 9 or 10, wherein the first and the second nozzle are placed at some distance from each other, preferably such that during use the first nozzle extends slightly below and / or in front of the second nozzle. 12. Device as claimed in any of the claims 9-11, wherein a pattern is provided with openings near the second nozzle, preferably openings with a diameter between 4 and 20 mm, more in particular between 6 and 15 mm and in particular approximately 8 to 10 mm. Device as claimed in any of the claims 9-12, wherein the foam-forming means comprise blowing means which are in fluid communication with the second nozzle. Device as claimed in any of the claims 9-13, wherein pumping means 20 are provided, arranged for passing water through the first nozzle, in particular between 5 and 20 liters per minute, more in particular between 6 and 15 liters per minute and preferably between 7 and 12 liters per minute. 15. Device as claimed in any of the claims 9-14, wherein the device 25 is driven by a combustion engine. ; : "J i