U.S. patent application number 16/107329 was filed with the patent office on 2019-01-03 for spray device with flow measurement.
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.
Application Number | 20190000065 16/107329 |
Document ID | / |
Family ID | 60951672 |
Filed Date | 2019-01-03 |
United States Patent
Application |
20190000065 |
Kind Code |
A1 |
GUTSMANN; Volker |
January 3, 2019 |
SPRAY DEVICE WITH FLOW MEASUREMENT
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) |
|
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.: |
16/107329 |
Filed: |
August 21, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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PCT/EP2017/066608 |
Jul 4, 2017 |
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16107329 |
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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
12/006 20130101; A01M 7/0017 20130101; B05B 12/08 20130101; B05B
12/1436 20130101; B05B 7/32 20130101; A01M 21/043 20130101; B05B
9/0861 20130101; A01M 25/006 20130101; A01M 7/0092 20130101; B05B
12/124 20130101; B05B 11/0054 20130101; A01M 7/0046 20130101 |
International
Class: |
A01M 7/00 20060101
A01M007/00; B05B 9/08 20060101 B05B009/08 |
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 first container for containing a first liquid, a
connector configured to removably connect to a second container
containing a second liquid, a spray nozzle in fluid communication
with the first container and configured to be in fluid
communication with the second container, a flow meter for measuring
the flow of the first liquid from the first container in a
direction of the spray nozzle, a mixing chamber comprising an inlet
for the first liquid, an inlet for the second liquid, and an outlet
for a mixture of the first liquid and the second liquid, and a
controller unit configured to adjust a flow of the second liquid in
the direction of the spray nozzle based on the measured flow of the
first liquid.
2. The spray device of claim 1, wherein the first container
comprises a pressure tank configured to be pressurized.
3. The spray device of claim 1, wherein the first container
comprises a flexible bag configured to be unpressurized.
4. The spray device of claim 1, wherein the spray device is a
backpack device.
5. The spray device of claim 1, wherein the spray nozzle is
replaceable.
6. The spray device of claim 1, comprising a pressure sensor
configured to measure a pressure in a supply line to the spray
nozzle.
7. The spray device of claim 6, 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.
8. The spray device of claim 1, wherein the second liquid is an
active substance concentrate, and the first liquid is a
diluent.
9. The spray device of claim 8, wherein the first liquid is
water.
10. The spray device of claim 8, wherein the second liquid
comprises a pesticide, an insecticide, a herbicide or a
fungicide.
11. The spray unit of claim 1, wherein the controller unit is
configured to adjust a mixing ratio for the first liquid and the
second liquid based on information stored on a second container
connected to the connector.
12. The spray unit of claim 1, wherein the flow meter comprises an
impeller sensor.
13. The spray device of claim 1, wherein the portable spray device
comprises a screen with a mesh size in the range of 10 .mu.m to 500
.mu.m.
14. The spray device of claim 1, wherein a volume through which the
second liquid flows on a way from the second container to the
mixing chamber when the spray device is operated is less than 50
ml.
15. The spray device of claim 1, wherein the mixing chamber is
configured to introduce the second liquid to the first liquid at an
angle in the range of 20.degree. to 160.degree., when the spray
device is operated.
16. The spray device of claim 1, wherein the control unit is
configured to adjust a flow of the second liquid based on the
measured flow of the first liquid such that the first liquid and
the second liquid exit the spray device through the spray nozzle
together as a mixture with a constant mixing ratio.
17. The spray device of claim 1, comprising an electrically
operated pump for conveying the second liquid.
18. A backpack spray device that can be carried by a user
comprising: a first container for containing a diluent, a connector
configured to removably connect to a second container containing an
active concentrate liquid, a spray nozzle in fluid communication
with the first container and the second container, a flow meter for
measuring the flow of the diluent from the first container in a
direction of the spray nozzle, a mixing chamber comprising an inlet
for the diluent, an inlet for the active concentrate liquid, and an
outlet for a mixture of the diluent and the active concentrate
liquid, and a controller unit configured to adjust a flow of the
active concentrate liquid in the direction of the spray nozzle
based on the measured flow of the diluent.
19. The backpack spray device of claim 18, wherein the first
container comprises a pressure tank configured to be
pressurized.
20. The backpack spray device of claim 18, wherein the first
container comprises a flexible bag configured to be
unpressurized.
21. The backpack spray device of claim 18, wherein the spray nozzle
is replaceable.
22. The backpack spray device of claim 18, comprising a pressure
sensor configured to measure a pressure in a supply line to the
spray nozzle.
23. The spray device of claim 22, 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.
24. The backpack spray device of claim 18, wherein the diluent is
water.
25. The spray unit of claim 18, wherein the controller unit is
configured to adjust a mixing ratio for the diluent and the active
concentrate liquid based on information stored on a second
container connected to the connector.
26. The backpack spray device of claim 18, wherein the backpack
spray device comprises a screen with a mesh size in the range of 10
.mu.m to 500 .mu.m.
27. The backpack spray device of claim 18, wherein a volume through
which the active concentrate liquid flows on a way from the second
container to the mixing chamber when the spray device is operated
is less than 50 ml.
28. The backpack spray device of claim 18, wherein the mixing
chamber is configured to introduce the active concentrate liquid to
the diluent at an angle in the range of 20.degree. to 160.degree.,
when the spray device is operated.
29. The backpack spray device of claim 18, wherein the control unit
is configured to adjust a flow of the active concentrate liquid
based on the measured flow of the diluent such that the diluent and
the active concentrate liquid exit the spray device through the
spray nozzle together as a mixture with a constant mixing
ratio.
30. A method for applying a mixture of a first liquid and a second
liquid using a portable spray device that can be carried by a user
comprising: filling a first container of the portable spray device
with a first liquid, removably connecting a second container
containing a second liquid to the portable spray device, and
spraying a mixture of the first liquid and the second liquid
through a spray nozzle of the spray device, wherein the spray
device measures the flow of the first liquid in a direction of the
spray nozzle, mixes the first liquid and the second liquid prior to
the spraying of the mixture of the first liquid and the second
liquid through the spray nozzle, and wherein the spray device
adjusts a flow of the second liquid in the direction of the spray
nozzle based on the measured flow of the first liquid.
Description
[0001] 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.
[0002] 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).
[0003] 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.
[0004] 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.
[0005] 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.
[0006] 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.
[0007] 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.
[0008] 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.
[0009] 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.
[0010] 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,
and in which no time-consuming cleaning is required.
[0011] 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.
[0012] 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 [0013] a first container for
receiving a first liquid, [0014] means for connecting a second
container with a second liquid to the spray device, [0015] a spray
nozzle, [0016] means for conveying the first liquid and the second
liquid from their containers in the direction of the spray nozzle,
[0017] a flow meter for measuring the flow of the first liquid from
the first container in the direction of the spray nozzle, [0018] 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 [0019] 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.
[0020] 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 a first
container, a spray nozzle and a valve, the method comprising the
following steps: [0021] filling the first container with the first
liquid, [0022] connecting a second container with the second liquid
to the spray device, [0023] directing the spray nozzle at the
target object, [0024] opening the valve, and [0025] applying the
mixture, wherein when opening the valve, the first liquid is
conveyed 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 values are transmitted to a control unit, the
control unit 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.
[0026] According to the invention, 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.
[0027] Both liquids are conveyed 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 the measured values
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.
[0028] The second container with the second liquid is embodied as a
replaceable container, so that different liquids can be used with
the spray device according to the invention. As a result, the spray
device is versatile.
[0029] 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
analogously, irrespective of the context.
[0030] 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.
[0031] 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.
[0032] Preferably, the 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.
[0033] The spray device is equipped with a first container for
receiving a first liquid.
[0034] The term "liquid" is intended to include solutions,
emulsions and suspensions.
[0035] The first liquid is preferably a diluent. The diluent is
used to dilute the second liquid that is in the second
container.
[0036] 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 this opening.
[0038] The first container may be made of any material that is
compatible with the first liquid. The term "compatible" is
understood to mean that the material is not chemically attacked by
the first liquid and that the material is impermeable to the first
liquid.
[0039] Depending on the means used to convey the first liquid from
the first container in the direction of the spray nozzle, the first
container must withstand an overpressure or it can be operated
without pressure. In an embodiment of the present invention the
first container a pressure tank, which can be pressurized to convey
the first liquid by means of pressure from the first container in
the direction of the spray nozzle.
[0040] In a preferred embodiment, the first container is operated
without pressure. Due to the fact that the container does not have
to withstand overpressure, it can be made of a more thin-walled and
lighter-weight material.
[0041] In a particularly 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.
[0042] The spray device according to the invention further has
means for connecting a second container with a second liquid to the
spray device. As already mentioned above, 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).
[0043] According to the invention, the second liquid container is
replaceable, which means that one can reversibly connect a
container filled with the second liquid to the spray device. The
second liquid container is then preferably removed again and, if
necessary, replaced by another container when it has been
emptied.
[0044] Means for reversibly connecting a container are well known.
The means for connecting the container may be, for example, a screw
or bayonet connection. To this end, there are mutually compatible
connection means on the spray device and on the second
container.
[0045] The second container is embodied to be compatible with the
second liquid--i.e., it is impermeable to the second liquid and is
not chemically attacked by the second liquid.
[0046] The second container may be embodied as a disposable or
reusable container, i.e., it is either reusable or not suitable for
reuse.
[0047] In a preferred embodiment, the second container is at least
partially embodied 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.
[0048] 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.
[0049] 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).
[0050] 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).
[0051] 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.
[0052] 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 dilution level may be stored there, i.e.
information about how the first and second liquids should be
mixed.
[0053] 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.
[0054] 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.
[0055] 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.
[0056] 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.
[0057] 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.
[0058] 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.
[0059] 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.
[0060] 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.
[0061] 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).
[0062] The spray device according to the invention further has
means for conveying the first liquid from the first container in
the direction of the spray nozzle. It is conceivable that the first
container can be pressurized, with which pressure the first liquid
is pushed from the first container through supply lines to the
spray nozzle.
[0063] Preferably, the means for conveying the first liquid from
the first container in the direction of the spray nozzle comprise
an electric pump. A pump has the advantage over a pressurized first
container that the first container must not be constructed pressure
resistant and thus is easier to transport. The first container
could, in principle, even be open.
[0064] 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.
[0065] 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.
[0066] In a preferred embodiment, the flow is measured with the aid
of a differential pressure sensor.
[0067] 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.
[0068] 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.
[0069] 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.
[0070] The spray device according to the invention comprises means
for conveying the second liquid from the second container in the
direction of the spray nozzle. This is preferably an electric pump
which is in communicative connection with the control unit.
[0071] In a particularly 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.
[0072] The first and the second liquid exit the spray device
through the spray nozzle together as a mixture. 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.
[0073] 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.
[0074] The mixing of the first liquid and the second liquid can be
promoted by suitable measures, for example by static mixing
elements.
[0075] 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.
[0076] 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..
[0077] 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.
[0078] 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, and/or a higher pressure in the first and second
containers which results in thicker container walls and, therefore,
in a higher load capacity. 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.
[0079] The spray device according to the invention 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.
[0080] 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.
[0081] 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.
[0082] 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.
[0083] 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.
[0084] 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.
[0085] 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.
[0086] 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. The pressure level depends, among other things, on
the geometry of the spray nozzle. It is conceivable that a spray
nozzle will require a pressure that must be within a defined
pressure range to generate a spray profile suitable for the
application.
[0087] Therefore, the pressure sensor is preferably connected to
the control unit, which adjusts the flow of the first and second
liquids so that the measured pressure is in a specified range.
[0088] The invention will be explained in more detail by means of
exemplary embodiments, but without wishing to limit the invention
to these examples.
[0089] 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), means
(15) for conveying the first liquid (11) from the first container
(10) in the direction of the spray nozzle (30), means (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).
[0090] The first container (10) is embodied as a pressure-resistant
container.
[0091] In FIG. 1, the means (15) for conveying the first liquid
(11) from the first container (10) are an air pump with which an
overpressure in the first container (10) relative to the ambient
pressure can be built up.
[0092] In FIG. 1, the means (25) for conveying the second liquid
(21) from the second container (20) are an electrically operated
pump.
[0093] The second liquid (21) meets the first liquid (11) in the
mixing chamber (80).
[0094] When the valve (40) is opened, the first liquid (11) is
conveyed by means of the conveying means (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
means (25) for conveying the second liquid (21) (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.
[0095] FIG. 2 shows schematically a preferred embodiment of the
spray device according to the invention.
[0096] 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).
[0097] 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).
[0098] 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.
[0099] 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). Preferably, the pumps
(15, 25) are electrically operated.
[0100] 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.
* * * * *