U.S. patent application number 16/107355 was filed with the patent office on 2019-02-28 for spray device with unpressurized spray material containers.
This patent application is currently assigned to Bayer CropScience Aktiengesellschaft. The applicant listed for this patent is Bayer CropScience Aktiengesellschaft. Invention is credited to Volker GUTSMANN, Byron REID.
Application Number | 20190060928 16/107355 |
Document ID | / |
Family ID | 60951672 |
Filed Date | 2019-02-28 |
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United States Patent
Application |
20190060928 |
Kind Code |
A1 |
GUTSMANN; Volker ; et
al. |
February 28, 2019 |
SPRAY DEVICE WITH UNPRESSURIZED SPRAY MATERIAL CONTAINERS
Abstract
The invention relates to the application of liquid active
substances with the aid of a portable spray device. The subject
matter of the present invention is a portable device for applying
active substances, and a method for applying active substances with
the aid of a portable spray device.
Inventors: |
GUTSMANN; Volker;
(Langenfeld, DE) ; REID; Byron; (Raleigh,
NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bayer CropScience Aktiengesellschaft |
Monheim am Rhein |
|
DE |
|
|
Assignee: |
Bayer CropScience
Aktiengesellschaft
Monheim am Rhein
DE
|
Family ID: |
60951672 |
Appl. No.: |
16/107355 |
Filed: |
August 21, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/EP2017/066611 |
Jul 4, 2017 |
|
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16107355 |
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62360548 |
Jul 11, 2016 |
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62360555 |
Jul 11, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B05B 9/08 20130101; B05B
12/124 20130101; A01M 7/0092 20130101; A01M 25/006 20130101; A01M
21/043 20130101; B05B 11/0054 20130101; A01M 7/0017 20130101; B05B
12/006 20130101; B05B 12/1436 20130101; B05B 12/08 20130101; A01M
7/0046 20130101; B05B 9/0861 20130101; B05B 7/32 20130101 |
International
Class: |
B05B 9/08 20060101
B05B009/08; A01M 21/04 20060101 A01M021/04; A01M 25/00 20060101
A01M025/00; A01M 7/00 20060101 A01M007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 11, 2016 |
EP |
16178764.3 |
Jul 11, 2016 |
EP |
16178766.8 |
Claims
1. A portable spray device that can be carried by a user
comprising: a container for containing a diluent, a connector
configured to removably connect to a container containing an active
substance concentrate, a spray nozzle in fluid communication with
the container for containing the diluent and configured to be in
fluid communication with the container containing an active
substance concentrate, a first pump configured to convey the
diluent from the container containing the diluent in a direction of
the spray nozzle, a second pump configured to convey the active
substance concentrate from the container containing the active
substance concentrate in a direction of the spray nozzle, a flow
meter for measuring the flow of the diluent, a mixing chamber
comprising an inlet for the diluent, an inlet for the active
substance concentrate, and an outlet for a mixture of the diluent
and the active substance concentrate, and a controller unit
configured to adjust a flow of the active substance concentrate in
the direction of the spray nozzle based on the measured flow of the
diluent.
2. The spray device of claim 1, wherein the container containing a
diluent comprises a flexible bag configured to be
unpressurized.
3. The spray device of claim 1, wherein the spray device is a
backpack device.
4. The spray device of claim 1, wherein the spray nozzle is
replaceable.
5. The spray device of claim 1, comprising a pressure sensor
configured to measure a pressure in a supply line to the spray
nozzle.
6. The spray device of claim 5, wherein the pressure sensor is
connected to the control unit and the control unit is configured to
keep the pressure in front of the spray nozzle within a predefined
range during use of the spray device.
7. The spray device of claim 1, wherein the diluent is water.
8. The spray device of claim 1, wherein the active substance
concentrate comprises a pesticide, an insecticide, an herbicide or
a fungicide.
9. The spray device of claim 1, wherein the controller unit is
configured to adjust a mixing ratio for the diluent and the active
substance concentrate based on information stored on a container
containing an active substance concentrate connected to the
connector.
10. The spray device of claim 1, wherein the flow meter comprises
an impeller sensor.
11. The spray device of claim 1, wherein the device comprises a
screen with a mesh size in the range of 10 .mu.m to 500 .mu.m.
12. The spray device of claim 1, wherein a volume through which the
active substance concentrate flows on a way from the container
containing an active substance concentrate to the mixing chamber
when the spray device is operated is less than 50 ml.
13. The spray device of claim 1, wherein the mixing chamber is
configured to introduce the active substance concentrate to the
diluent at an angle in the range of 20.degree. to 160.degree., when
the spray device is operated.
14. The spray device of claim 1, wherein the control unit is
configured to adjust a flow of the active substance concentrate
based on the measured flow of the diluent such that the diluent and
the active substance concentrate exit the spray device through the
spray nozzle together as a mixture with a constant mixing
ratio.
15. The spray device of claim 1, wherein the control unit is
configured to read information from a memory of the container
containing the active substance concentrate.
16. The spray device of claim 15, wherein the information is
related to mixing ratio indicating in what ratio the diluent and
the active substance concentrate should be mixed.
17. A method for applying a mixture of a diluent and an active
substance concentrate using a portable spray device that can be
carried by a user comprising: filling a container of the portable
spray device with a diluent, removably connecting a container
containing an active substance concentrate to the portable spray
device, and spraying a mixture of the diluent and the active
substance concentrate through a spray nozzle of the spray device,
wherein a first pump conveys the diluent from the container
containing the diluent in a direction of the spray nozzle, a second
pump conveys the active substance concentrate from the container
containing the active substance concentrate in a direction of the
spray nozzle, the spray device measures the flow of the diluent in
a direction of the spray nozzle, mixes the diluent and the active
substance concentrate prior to the spraying of the mixture of the
diluent and the active substance concentrate through the spray
nozzle, and wherein the spray device adjust a flow of the active
substance concentrate in the direction of the spray nozzle based on
the measured flow of the diluent.
18. The method of claim 17, wherein the container containing a
diluent comprises a flexible bag configured to be
unpressurized.
19. The method of claim 17, wherein the spray device is a backpack
device.
20. The method of claim 17, wherein the spray nozzle is
replaceable.
21. The method of claim 17, further comprising sensing a pressure
in a supply line to the spray nozzle.
22. The spray device of claim 21, further comprising maintaining a
pressure in front of the spray nozzle within a predefined range
during use of the spray device.
23. The method of claim 17, wherein the diluent is water.
24. The method of claim 17, wherein the active substance
concentrate comprises a pesticide, an insecticide, an herbicide or
a fungicide.
25. The method of claim 17, further comprising adjusting a mixing
ratio for the diluent and the active substance concentrate based on
information stored on the container containing an active substance
concentrate.
26. The method of claim 17, wherein the flow meter comprises an
impeller sensor.
27. The method of claim 17, wherein the portable spray device
comprises a screen with a mesh size in the range of 10 .mu.m to 500
.mu.m.
28. The method of claim 17, wherein a volume through which the
active substance concentrate flows on a way from the container
containing an active substance concentrate to the mixing chamber
when the spray device is operated is less than 50 ml.
29. The method of claim 17, wherein the mixing chamber is
configured to introduce the active substance concentrate to the
diluent at an angle in the range of 20.degree. to 160.degree., when
the spray device is operated.
30. The method of claim 17, comprising adjusting a flow of the
active substance concentrate based on the measured flow of the
diluent such that the diluent and the active substance concentrate
exit the spray device through the spray nozzle together as a
mixture with a constant mixing ratio.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of
International Application No. PCT/EP2017/066611, filed
internationally on Jul. 4, 2017, which claims the benefit of U.S.
Provisional Application Nos. 62/360,548, filed Jul. 11, 2016 and
62/360,555, filed on Jul. 11, 2016, and European Application Nos.
16178766.8, filed Jul. 11, 2016 and 16178764.3, filed Jul. 11,
2016.
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0002] FIG. 1 illustrates a spray device, according to some
embodiments; and
[0003] FIG. 2 illustrates a spray device, according to some
embodiments.
DETAILED DESCRIPTION
[0004] The present invention relates to the application of liquid
active substances with the aid of a portable spray device. The
subject matter of the present invention is a portable device for
applying active substances, and a method for applying active
substances with the aid of a portable spray device.
[0005] Portable spray devices for applying active substances such
as pesticides, insecticides, herbicides and fungicides are known
(DE102013109785A1, US2006/0249223A1, US2006/0102245 A1,
US2006/0261181A1, US2005/0006400A1).
[0006] Commonly used are spray devices, which are referred to as
compression sprayers. They comprise a tank for receiving the liquid
to be sprayed. A generally manually operated air pressure pump
which forms part of the tank contains a conventional piston rod
assembly and an actuating handle for the same. This air pressure
pump is used to generate an air pressure over the liquid to be
sprayed. The pressurization of the tank is effected by the operator
periodically actuating the pump until a desired tank pressure is
reached. The spray liquid exits through a tube immersed in the
liquid in the tank due to the air pressure exerted thereon and then
flows through a tube, a spray jet valve at the outer end of the
tube, an extension pipe and finally through a spray nozzle to the
selected target area.
[0007] A disadvantage of such a spray device is that the ejection
pressure can not be kept constant by the manually operated air
pump. The result is a spray pattern that is changing according to
the flow rate. Accordingly, the active substance can only be dosed
inaccurately.
[0008] An electrically operated air pump can remedy this, but for a
targeted, accurate and uniform application of the active substance,
it is necessary that the pressure in the tank is kept constant. In
addition, the tank must be pressure stable. In most cases such
tanks are therefore made of metal or thick-walled plastic. The
tanks are correspondingly heavy and unwieldy.
[0009] Pesticides, insecticides, herbicides and fungicides are
nowadays increasingly brought to market in the form of
concentrates. Concentrates have the advantage of lower transport
costs. The user must dilute the active substance before use. The
instructions for dilution are usually found on the package or on a
package insert.
[0010] However, a dilution made by the user is disadvantageous for
the following reasons: The user may come into undesirable contact
with the active substance. It is conceivable that the user may make
mistakes in calculating the amounts of concentrate and diluent.
High viscosity of the concentrate may result in an inaccurate
volumetric measurement of the required amount.
[0011] An inaccurate dosing of active substances can have a number
of unwanted consequences. The treatment of the sprayed object can
be ineffective or it can lead to an overdose. It is conceivable
that regulatory requirements on quantities delivered are not met.
It is conceivable that inventory control errors may occur because
the quantities dispensed have been calculated incorrectly.
[0012] Another disadvantage of the spray device described above is
that the tank must first be cleaned when using another active
substance. If necessary, the cleaning liquid must be disposed
of.
[0013] Based on the described prior art, the object was to provide
a portable device for applying active substances, which is easy to
handle, in which no manual dilution of concentrates is required,
which delivers a precisely definable amount of active substance,
which is convenient for the user to carry and transport, and in
which no time-consuming cleaning is required.
[0014] According to the invention this object is achieved by the
subject of independent claims 1 and 10. Preferred embodiments can
be found in the dependent claims as well as in the description.
[0015] A first subject of the present invention is thus a spray
device for pest control, which can be transported by a person
without mechanical aids, comprising [0016] a first container with a
first liquid, [0017] a second container with a second liquid,
[0018] a spray nozzle, [0019] a first pump for conveying the first
liquid from the first container in the direction of the spray
nozzle, [0020] a second pump for conveying the second liquid from
the second container in the direction of the spray nozzle, [0021] a
flow meter for measuring the flow of the first liquid from the
first container in the direction of the spray nozzle, [0022] a
mixing chamber having an inlet for the first liquid, an inlet for
the second liquid and an outlet for a mixture of first and second
liquids, and [0023] a control unit configured to adjust the flow of
the second liquid in the direction of the spray nozzle based on the
measured flow of the first liquid.
[0024] A further subject of the present invention is a method for
pest control by applying a mixture of a first and a second liquid
to a target object by means of a spray device that can be
transported by a person without mechanical aids, comprising two
containers, a spray nozzle and a valve, the method comprising the
following steps: [0025] directing the spray nozzle at the target
object, [0026] opening the valve, and [0027] applying the mixture,
wherein when opening the valve, the first liquid is conveyed by a
first pump from the first container in the direction of the spray
nozzle, the flow of the first liquid is measured by a flow meter
and the measured value is transmitted to a control unit, the
control unit controls a second pump and adjusts the flow of the
second liquid from the second container in the direction of the
spray nozzle, so that the first and second liquids pass through the
spray nozzle in a constant mixing ratio.
[0028] According to the invention, the conveyance of the first and
the second liquid from their containers in the direction of a spray
nozzle takes place by means of two pumps. As a result, in
particular, the first container with the first liquid can be
operated without pressure. It can be made of lighter and more
flexible material than the pressure tanks of the known compression
sprayers.
[0029] In addition, mixing the first and the second liquids occurs
automatically--a manual mixing by a user is not required. The first
and second liquids are kept in separate containers and are combined
just prior to application onto the target object. This will help to
avoid potential user errors in making the mix, and accidental
contamination of the user with the liquids.
[0030] Both liquids are conveyed by means of the respective pump in
the direction of the spray nozzle. They exit the spray device
through the spray nozzle together as a mixture. The mixing ratio is
automatically set based on the flow of the first liquid. For this
purpose, a flow meter measures the flow of the first liquid from
the first container in the direction of the spray nozzle and
transmits it to the control unit. The control unit then adjusts the
flow of the second liquid in the direction of the spray nozzle on
the basis of this flow of the first liquid. If, for example, the
flow of the first liquid decreases, the flow of the second liquid
is reduced, so that the mixing ratio remains constant. As the flow
of the first liquid increases, the flow of the second liquid is
increased accordingly.
[0031] The individual elements which characterize the spray device
according to the invention and the method according to the
invention are explained in more detail below. This explanation does
not distinguish between spray device and method. Instead, the
following descriptions apply to all subjects of the invention.
[0032] The spray device according to the invention is
transportable. Transportable is understood to mean that the device
can be brought from one place to another place by a person without
mechanical aids.
[0033] In an embodiment, the spray device is embodied so that the
user carries in transport one part of the spray device comprising
the first tank in one hand, and another part of the spray device
comprising the spray nozzle in the other.
[0034] Preferably, the spray device is embodied so that the user
can carry and transport a part of the spray device, which includes
the first liquid container, on the back (backpack device). Another
part, which includes the spray nozzle, is still carried with one
hand, but the second hand is now free. To carry the container on
the back, it is equipped with appropriate straps.
[0035] The spray device is equipped with a first container for
receiving a first liquid. The term "liquid" is intended to include
solutions, emulsions and suspensions.
[0036] The first liquid is preferably a diluent. The diluent is
used to dilute the second liquid that is in the second container.
In a preferred embodiment, the diluent is water.
[0037] The first container preferably has an opening which can be
closed with a resealable closure. The first container can be filled
with the first liquid by means of the opening.
[0038] The first container may be made of any material that is
compatible with the first liquid. This means that the material is
not chemically attacked by the first liquid and that the material
is impermeable to the first liquid.
[0039] The first tank is operated without pressure. Due to the fact
that the container does not have to withstand overpressure, it can
be made from thin-walled and lightweight material. In a preferred
embodiment, the first container is embodied as a flexible bag. Such
a bag preferably has straps so that it can be strapped to and worn
like a backpack on the back.
[0040] The second container can also be operated without pressure.
It contains the second liquid. Accordingly, the second container
must be compatible with the second liquid, that is, the material of
the second container is not chemically attacked by the second
liquid, and the material is impermeable to the second liquid.
[0041] The second liquid is preferably a concentrate to be diluted
by the diluent. Preferably, the second liquid is an active
substance formulation, preferably comprising a pesticide,
insecticide, herbicide or fungicide. In a particularly preferred
embodiment, it is a pesticide concentrate. Preferably, the
pesticide is an agent for controlling animal pests, more preferably
an acaricide (for mites/arachnids), an insecticide (for insect
pests) or a rodenticide (for rodents).
[0042] The second container is embodied as a replaceable disposable
or reusable container. It can be reversibly connected to the spray
device. The spray device and the second container have
corresponding connecting means.
[0043] The means for connecting the container may be, for example,
a screw or bayonet connection.
[0044] In a preferred embodiment, the second container is at least
partially made of a plastic. Plastics are known to be chemically
inert to many substances. They are also light, can be processed
readily and can be formed in almost any shape.
[0045] In a preferred embodiment, the second container is embodied
as a pressure vessel. Preferably, it contains a pressurized
propellant separated from the second liquid, in addition to the
second liquid. The second container preferably has a valve.
Preferably, the valve is automatically opened when the second
container is connected to the spray device according to the
invention. The pressurized propellant pushes the second liquid from
the second container into the spray device. Another valve located
in the spray device stops the further flow of the second liquid.
This additional valve preferably opens when a user starts an
application operation, usually by actuating a handle.
[0046] The second container embodied as a pressure vessel may for
example consist of aluminum or tin sheet--materials that are
pressure resistant and, for example, are used in spray cans (e.g.
shaving foam).
[0047] It is conceivable that the second container contains a bag
with the second liquid, wherein the bag is connected to the valve
(valve bag system). The propellant surrounds the bag filled with
the second liquid and exerts the necessary pressure for expelling
the second liquid from the second container (see, e. g.,
DE69820260T2, U.S. Pat. No. 5,505,039, EP0718213A).
[0048] It is also conceivable that the propellant and the second
liquid are separated by a piston (see, e. g. DE3934237A1). The
propellant exerts pressure on the piston. If the valve is opened,
the second liquid is forced out of the second container by the
piston. It is conceivable, for example, the use of a ZIMA
piston.
[0049] In a preferred embodiment of the present invention, the
second container has means that allow communication with the
control unit of the spray device. In a preferred embodiment, these
means allow the control unit to determine a mixing ratio. It is
conceivable, for example, that the means for connecting the second
container to the spray device have electrical contacts which
establish an electrical contact between the spray device and the
control unit when the second container is connected, by means of
which electronic communication between the control unit and the
second container is made possible. The second container may, for
example, comprise an electronic memory which can be read by the
control unit by means of the established contact. Information about
the liquid present in the second container can be stored in this
memory. In particular, a mixing ratio may be stored there, i. e.
information about how the first and second liquids should be
mixed.
[0050] If the second liquid is a concentrate that must be diluted
with a diluent prior to application, the dilution level to be set
should be noted and/or stored at or on the container. In the
preferred embodiment described, the dilution level to be set is
stored in a form in which it can be determined by the control unit.
This can be done, as described, by means of an electronic
communication. Of course, contactless communication is also
possible, i. e. by means of electromagnetic waves (Bluetooth,
near-field communication, etc.) in addition to the contact-based
communication described.
[0051] Furthermore, the spray device according to the invention has
a spray nozzle. By means of the spray nozzle, a mixture of the
first and second liquids is delivered to a target object. A desired
spatial distribution of the applied mixture can be achieved by
means of the spray nozzle. Typically, the spray nozzle transforms
the liquid passing through it into droplets having a specific
droplet size distribution which depends, among other things, on the
pressure of the liquid, the flow rate of the liquid and the
geometry of the spray nozzle.
[0052] Preferably, the spray nozzle is replaceable, so that a user
can select a spray nozzle adapted to the application and the target
object with a desired drop size distribution and spatial
distribution of the spray material.
[0053] The spray nozzle may, for example, be lance-shaped or
pistol-shaped, or have a different shape. Preferably, it is
embodied so that it can be held with one hand by the user and
directed to the target object.
[0054] Typically, the spray nozzle has a handle that is actuated by
the user to start a spraying operation. Usually, a valve is opened
by operating the handle, so that first and second liquid are
conveyed from their respective containers in the direction of the
spray nozzle and through the spray nozzle to the target object.
[0055] In a preferred embodiment, the interchangeable spray nozzle
and the control unit have means that allow the control unit to
identify the presence of a spray nozzle and/or the type of spray
nozzle present. It is conceivable, for example, that the control
unit only initiates the conveyance of the liquids from their
containers in the direction of the spray nozzle, only if a spray
nozzle is connected also. If no spray nozzle is connected, there
will be no conveyance, e. g. for safety reasons. Furthermore, it is
conceivable that the control unit adapts the parameters for
conveying the liquids to the type of spray nozzle present, in order
to allow an optimum spray result. It is conceivable that a spray
nozzle requires a minimum pressure of the incoming liquid in order
to produce a desired spatial distribution of the spray liquid. This
minimum pressure could be coded at the spray nozzle in a manner
that can be read by the control unit so that the user does not have
to manually set such parameters.
[0056] Preferably, a valve is mounted in front of the spray nozzle.
Preferably, this valve can be operated manually, so that the user
can direct the spray nozzle on the target object and start the
spraying operation by manually opening the valve.
[0057] It is also conceivable that the valve is opened
automatically. It is conceivable, for example, that the spray
device has a sensor which identifies the spatial position of the
spray nozzle and automatically opens or closes the valve at a
certain position. It is conceivable, for example, that the valve is
closed when the spray nozzle is directed to the ground and is
opened when the spray nozzle is lifted in the horizontal.
[0058] It is also conceivable that the valve is opened
automatically when the spray nozzle approaches the target object.
This can be done for example by means of sensors or GPS-based
(GPS=Global Positioning System).
[0059] The spray device according to the invention has two pumps; a
first pump for conveying the first liquid from the first container
in the direction of the spray nozzle, and a second pump for
conveying the second liquid from the second container in the
direction of the spray nozzle.
[0060] In a preferred embodiment, a stepper motor metering pump is
used as the second pump for conveying the second liquid (see, e.
g., DE102004047584, WO2012048976, DE102009006203). By means of the
stepper motor drive, even small amounts of the second liquid can be
added with high accuracy to the first liquid.
[0061] The spray device according to the invention has a flow meter
for measuring the flow of the first liquid from the first container
in the direction of the spray nozzle. By means of such a flow
meter, the amount of liquid flowing per unit of time in the
direction of the spray nozzle is detected. Amount of liquid is
understood to mean the volume or the mass, depending on the
measuring method used.
[0062] The flow meter is preferably one that is usually used in
closed piping, such as a magnetic-inductive flow meter, a floating
element flow meter, an ultrasonic flow meter, a Coriolis mass flow
meter, a calorimetric flow meter or a vortex flow meter. But it is
also conceivable to use a measuring orifice or a pitot tube.
[0063] In a preferred embodiment, the flow is measured with the aid
of a differential pressure sensor.
[0064] In a further preferred embodiment, an impeller sensor is
used for flow measurement. The measuring principle is based on the
fact that an impeller assumes a speed proportional to the flow
velocity of a fluid through which the impeller is driven. To
measure the speed a permanent magnet can be attached to the
impeller, which moves with the impeller. A Hall sensor, past which
the permanent magnet passes, can be used as a pulse counter. The
number of pulses measured per unit of time is proportional to the
speed of the impeller and thus to the flow rate of the liquid.
[0065] Details on flow measurement can be found, for example, in
the following textbook: K. W. Bonfig: Technische Durchflussmessung,
Vulkan-Verlag Essen, 3rd edition, 2002, ISBN 3-8027-2190-X.
[0066] Based on the amount of liquid of the first liquid flowing in
the direction of the spray nozzle, the control unit adjusts the
flow of the second liquid from the second container in the
direction of the spray nozzle.
[0067] First and second liquid exit the spray device through the
spray nozzle together as a mixture.
[0068] It is conceivable that the first liquid and the second
liquid are combined in the spray nozzle by means of corresponding
supply lines. However, it has been found that the first and second
liquids are not sufficiently mixed in this case when they reach the
target object. Preferably, therefore, there is a mixing chamber in
front of the spray nozzle, in which the first and the second liquid
are introduced by means of two separate supply lines. In the mixing
chamber, mixing of the first and second liquids then occurs before
the mixture enters the spray nozzle.
[0069] The mixing chamber accordingly has an inlet for the first
liquid, an inlet for the second liquid, and an outlet for a mixture
of first and second liquids. The mixing chamber may also be a
portion of the supply line for the first liquid to the spray
nozzle, into which a line for the second liquid opens.
[0070] The mixing can be promoted by suitable measures, for example
by static mixing elements.
[0071] The lines between the second container and the mixing
chamber are preferably embodied to have a small volume. After an
application operation, residual amounts of the (undiluted) second
liquid remain in the lines between the second container and the
mixing chamber. If necessary, these residues must be disposed of;
if necessary, the lines must be cleaned when changing the second
container. The smaller the volume, the lower the residual
quantities are that have to be disposed of and the smaller the
volume to be cleaned. Preferably, the volume that the second liquid
may occupy on its way in the direction of the mixing chamber
between the second container and the mixing chamber is less than 50
ml, more preferably less than 30 ml, even more preferably less than
10 ml.
[0072] Preferably, the second liquid is added transversely to the
flow direction of the first liquid. The term "transverse" means: at
an angle in the range of 20.degree. to 160.degree., preferably
50.degree. to 130.degree., more preferably 70.degree. to
110.degree., most preferably 80.degree. to 100.degree..
[0073] In a preferred embodiment, the second liquid is dosed by a
flow divider into the first liquid. In a further preferred
embodiment, the second liquid is dosed into the first liquid and
both liquids pass together through a flow divider. A flow divider
is a static element which divides a flow of a liquid into a
plurality of stream filaments. Preferably, the flow divider is
embodied in the form of a screen, i. e., in the flow direction the
liquid(s) is(are) forced through a screen, which divides the flow
into stream filaments. By means of such a screen, in particular,
drops of the second liquid which enter the first liquid are divided
into a plurality of small drops. Turbulence behind the screen leads
to dispersion of the small drops in the first liquid. Surprisingly,
it has been found that such a screen is sufficient as a static
mixing element in order to achieve sufficient mixing of first and
second liquids at the spray nozzle. If no screen is used, it can be
observed that individual drops of the second liquid are retained on
the route from the mixing chamber to the spray nozzle and thus an
inhomogeneous mixture exits the spray nozzle. Further static mixing
elements other than a screen are surprisingly not necessary to
achieve sufficient mixing at the spray nozzle. In addition, a
screen has the advantage of a much lower pressure loss compared to
a classic static mixer, which alternately divides the fluid flow,
twists it and combines it. There should be a pressure in front of
the spray nozzle that is within a defined range so that the spray
nozzle can achieve a desired spatial distribution of the liquid.
This pressure is provided by the conveying means of the spray
device. However, the pressure provided by the conveying means must
be higher than the pressure required in front of the spray nozzle
in order to compensate for the pressure loss across the existing
supply lines, mixing chamber, mixing elements, etc. However, a
higher pressure loss also means a higher energy expenditure to
compensate for the pressure loss, which results in a higher load
capacity when using battery-operated pumps. Preferably, the screen
is embodied like a mesh with a mesh size of 10 .mu.m to 500 .mu.m,
more preferably 50 .mu.m to 250 .mu.m, most preferably 80 .mu.m to
120 .mu.m. The webs between the meshes usually have a width which
is smaller than the mesh size in order to minimize the flow
resistance and thus the pressure loss.
[0074] The spray device according to the invention also has a
control unit. This control unit provides for an adjustment of the
amount of the second liquid from the second container in the
direction of the spray nozzle. According to the invention, this
adjustment is carried out on the basis of the flow of the first
liquid from the first container in the direction of the spray
nozzle, measured by means of the flow meter. Another parameter that
is included in the adjustment is the mixing ratio to be set. This
mixing ratio can be specified by the user by inputting the mixing
ratio in the control unit, for example; but it is also possible
that the control unit detects the mixing ratio by a communication
with a memory unit of the second container.
[0075] As described above, in a preferred embodiment of the present
invention, the control unit is connected to the replaceable second
container such that the control unit can receive, from the
replaceable second container, a dilution level to be set for the
concentrate contained in the replaceable second container.
[0076] The control unit receives the measured values of the flow
meter in relation to the flow of the first liquid and adjusts the
flow of the second liquid so that the first and second liquids exit
the spray device via the spray nozzle as a mixture with a constant
mixing ratio. A "constant mixing ratio" is understood to mean that
the mixing ratio over the spraying time is within a predefined
range.
[0077] In a further preferred embodiment, the control unit detects
the amount of second liquid applied and stores this value and
transmits this value to an external computer system, for example at
a user-definable time. In this way, the amount of applied second
liquid can be tracked.
[0078] In a preferred embodiment, the position (which can be
determined by GPS) of the application is also detected in addition
to the quantity of the applied second liquid in each case.
[0079] In a further preferred embodiment, the residual quantity of
second liquid in the second container is determined on the basis of
the applied quantity of second liquid. Preferably, the value for
this residual quantity is stored in a memory unit in the spray
device and/or at the second container.
[0080] In a preferred embodiment, the spray device according to the
invention has a pressure sensor which measures the pressure in the
supply line to the spray nozzle.
[0081] If the first and the second liquids are conveyed in the
direction of the spray nozzle, pressure builds up in front of the
spray nozzle. In order to produce a consistent spray pattern, it is
necessary that this pressure remains constant during the spraying
operation. This is ensured by connecting the pressure sensor to the
control unit, which adjusts the flow of the first and second
liquids so that the measured pressure remains constant.
[0082] The invention will be explained in more detail by means of
exemplary embodiments, but without wishing to limit the invention
to these examples.
[0083] FIG. 1 shows schematically an embodiment of the spray device
according to the invention. The spray device comprises a first
container (10) with a first liquid (11), a second container (20)
with a second liquid (21), a spray nozzle (30), a valve (40), a
first pump (15) for conveying the first liquid (11) from the first
container (10) in the direction of the spray nozzle (30), a second
pump (25) for conveying the second liquid (21) from the second
container (20) in the direction of the spray nozzle (30), a mixing
chamber (80), a flow meter (2) for measuring the flow of the first
liquid (11) from the first container (10) in the direction of spray
nozzle (30), and a control unit (1).
[0084] The first container (10) is embodied as a flexible bag
comprising an opening for filling the first liquid (11), wherein
the opening can be reversibly closed by a closure (12).
[0085] The second liquid (21) meets the first liquid (11) in the
mixing chamber (80).
[0086] When the valve (40) is opened, the first liquid (11) is
conveyed by means of the first pump (15) in the direction of the
spray nozzle (30). The flow of the first liquid is measured by flow
meter (2). The flow meter (2) is communicatively connected with the
control unit (1) (shown by the dashed line). The flow measured by
the flow meter (2) is transmitted to the control unit (1). The
control unit (1) is communicatively connected with the second pump
(25) (shown by the dashed line). The control unit (1) adjusts the
flow of the second liquid (21) in the direction of the spray
nozzle, so that the first liquid and the second liquid exit the
spray nozzle in the form of a mixture (50) with a constant mixing
ratio.
[0087] FIG. 2 shows schematically a preferred embodiment of the
spray device according to the invention.
[0088] The spray device comprises a control unit (1), a flow meter
(2), a pressure sensor (3), a first container (10) with a first
liquid (11), a second container (20) with a second liquid (21), a
first pump (15), a second pump (25), a spray nozzle (30), a mixing
chamber (80) and a valve (40). The first container (10) is embodied
as a flexible bag having an opening for filling the first liquid
(11), wherein the opening can be reversibly closed by a closure
(12).
[0089] The second container (20) is embodied as a replaceable
cartridge. The cartridge is connected by means of connecting means
(22a) for connecting the cartridge to the spray device with the
spray device. The spray device has connecting means (22b)
compatible with the connecting means (22a) of the cartridge.
[0090] The control unit (1) is communicatively connected (shown by
dashed lines) with the flow meter (2), the pressure gauge (3), the
first pump (15) and the second pump (25). The pumps (15, 25) are
electrically operated.
[0091] When the valve (40) is opened, the first liquid (11) is
conveyed out of the first container (10) in the direction of the
spray nozzle (30) by means of the first pump (15). This flow of the
first liquid (11) is measured by means of the flow meter (2). The
measured value is transmitted to the control unit (1). At the same
time, the pressure in the supply line to the spray nozzle (30) is
measured by means of the pressure sensor (3). This measured value
is also transmitted to the control unit (1). The control unit (1)
adjusts the flow of the first liquid (11) and the second liquid
(21) in the direction of the spray nozzle (30) by means of the
first pump (15) and by means of the second pump (25) so that the
exiting mixture (50) has a constant mixing ratio of first and
second liquids, and so that the pressure in the supply line in
front of the spray nozzle is within a predetermined range.
* * * * *