WO2013117297A1

WO2013117297A1 - Device for monitoring a liquid level

Info

Publication number: WO2013117297A1
Application number: PCT/EP2013/000182
Authority: WO
Inventors: Georg Bonn
Original assignee: Bonnel Technologie Gmbh
Priority date: 2012-02-06
Filing date: 2013-01-22
Publication date: 2013-08-15
Also published as: DE102012002115A1

Abstract

The invention relates to a device for monitoring a liquid level. In order to provide a device for monitoring a liquid level, which device makes it possible to output the switching signal in a particularly reliable manner over a long period, a device (3) for monitoring a liquid level (4) is proposed, said device having a floating body (5), and having a switch (6) which is arranged in the floating body (5) and is designed to output a switching signal on the basis of the level (4) of the liquid (1), characterized by a radio transmitter (7) for wirelessly transmitting the switching signal to a receiver (8) arranged outside the floating body (5).

Description

The invention relates to a device for monitoring a fluid level, preferably for monitoring a fluid level

Liquid levels in a container, which may be, for example, a tank, a barrel or the like, or may be a structure such as a cistern, a pit or the like.

From the prior art are for monitoring a

Fluid levels different floats with

Switching devices are known, with the help of which when reaching a certain liquid level, a mechanical

Switch is pressed. The switching signal is transmitted via a wired connection to a receiver, which is usually located outside the container.

The receiver of the switching signal may be

for example, a central control unit of a

Sewage or sewage treatment plant or around the tank

associated pump or any other device act. The switching signal thus serves as an input signal for a subsequent signal processing and / or as an immediate control signal for operating a device.

Due to changing liquid levels, such an electrical connection line is regularly exposed to mechanical stress. If the liquid level changes periodically or the surface of the liquid carrying the floating body oscillates periodically, as is the case, for example, with the occurrence of liquid waves, such as may arise through aeration in sewage treatment plants, the

CONFIRMATION COPY mechanical stress on the connecting line so high that it breaks after a short time or otherwise damaged. An object of the present invention is to provide a

Device for monitoring a fluid level

to provide a particularly reliable output of the switching signal over a long period is possible.

This object is achieved by a device according to claim 1. Advantageous embodiments of the invention are in the

Subclaims specified.

The inventive device for monitoring a

Fluid levels includes a float, a switch disposed in the float, which is used to issue a

Switching signal is formed depending on the level of the liquid, and a radio transmitter for wireless

Transmission of the switching signal to one outside the

Floating body arranged receiver.

A basic idea of the invention is to dispense with the use of a connecting line between the switch on the one hand and the receiver of the switching signal on the other hand. A mechanical load on the connecting line by changing liquid levels is therefore from the outset

locked out. The invention proposes to transmit the switching signal wirelessly with the aid of a radio transmitter arranged in the floating body. As a result, a particularly high reliability in the signal transmission is ensured. The monitoring device can be operated without repair or replacement of the connecting line over a long period of time. The radio transmitter used is preferably designed to form a short-range radio link, for example with a range of 50 meters inside buildings. Since usually only a single switching signal must be transmitted, the duration of the radio operation is also very short. The transmission energy required for the emission of the radio signal for short-term transmission operation radio signal is therefore very low. The use of radio transmitters to transmit

Switching signals is generally known to the person skilled in the art. To operate the radio transmitter is usually a

Supply line needed for connection to a power supply. However, the use of such a supply line is self-sufficient with the inventive idea

Monitoring device incompatible. As an alternative, therefore, offers the use of batteries for power supply. In particular, in such applications in which the monitoring device according to the invention with particular

Advantage is applicable, namely when using the

Monitoring device in hard to reach places or in places that are rarely used for other reasons

it can be accessed, it has to be special

proven advantageous to provide the monitoring device with a power supply device, which the

Radio transmitter supplied with electrical energy derived from the movement of the float.

The power supply device comprises for this purpose an energy converter, preferably an electromechanical converter, for converting kinetic energy of

Float in electrical energy to power the radio transmitter. The energy gained in this way becomes either directly used for the operation of the radio transmitter, for which purpose the energy converter electrically with the

Radio transmitter is connected, or the energy obtained is stored in a purpose intended for this purpose buffer. In this case, the cache is

on the one hand electrically connected to the energy converter and on the other hand electrically connected to the radio transmitter. to

Energy storage in the cache can

For example, capacitors are used. Another way of storing energy is to use a rechargeable battery of suitable technology, for example one

Nickel-metal hydride accumulator with low

Self-discharge. The radio transmitter used can be used together with the optional buffer and the energy converter or parts of the

Energy converter and the switch or parts of the switch be designed as a compact unit that can be combined in the manner of a module with different floats. To compact design contributes that the

Transmitting antenna is preferably included as an integral component in the radio transmitter.

In the movement of the float, which is used directly or indirectly for the production of electrical energy, it may, depending on the design of the monitoring device and in particular depending on the design of the used floating body to an up and down movement of the

Floats act as they are due to a change in the

Fluid levels is caused. Instead of this substantially vertical movement or in addition to this, it can also be in the used movement of the float to a reciprocating motion, so a substantially horizontal movement of the float at a constant level of liquid act, for example, caused by currents or the like. The energy supply device used can use energy converters of different types. Particularly advantageous is, for example, the use of a

Linear generator, which converts a linear kinetic energy into electrical energy. This type of energy converter can be structurally particularly simple and therefore inexpensive to manufacture. In this case, an embodiment has proved to be particularly advantageous in which a permanent magnet moving due to a movement of the floating body is provided, which moves relative to an electrical coil. Such an electrodynamic converter is for

Generation of small amounts of electrical energy, as needed for a short-term operation of the radio transmitter, sufficient. Alternatively to the use of a linear generator can

For example, a piezoelectric transducer can be used, the piezoelectric element for generating an electrical voltage from a functional body with a mechanical force

is acted upon, caused by standing in connection with a movement of the float body movement of the functional body. Piezo elements can be piezocrystals as well as piezoelectric ceramics

be used. The functional body acting on the piezoelectric element, as well as the magnet serving as a functional body in an electrodynamic converter, is preferably one in which

Floating body arranged to move during a movement of Floating body moving functional body, which is preferably a defined movement,

in particular a movement on a given

Trajectory.

Other converters that can be used in the power supply device are, for example, electromechanical rotary converters for use of rotational movements and

Vibration converter for the use of vibrations,

for example, wave movements of the liquid in the container.

As part of the rotary converter can be used, for example, a ball-bearing rotor, as he used to operate the automatic Aufziehmechanismus a mechanical

Wristwatch is used.

Even when snapping a spring element, for example, caused by a mechanical loading by a moving depending on the liquid level

Functional body, a short voltage pulse can be generated by electromagnetic induction, the

Power supply of the radio transmitter is used. In a structurally particularly simple, thus very robust and less prone to error and at the same time inexpensive to produce monitoring device of the switch is designed as a mechanically actuated switch. This is preferably a microswitch.

Regardless of the specific design of the switch basically different types of switches can be used. Depending on the application, this may be Normally closed switch or normally-open switch, or alternatively, toggle switch with NC and NO contact.

Particularly advantageous is an embodiment of a switch, wherein a functional body in the form of a ball in

Depending on the inclination of the float due to a shift of emphasis on a given

Movement changed its position and, for example via a lever system, the switch pressed. If this type of switch is used, the float is preferably by means of a holding element, for example in the form of a flexible or rigid holding rod, at a mostly stationary breakpoint, for example on a wall of the

Liquid container, fixed so that a change in the liquid level, a change in the inclination of the

Floating body has the consequence. The retaining element is

Preferably carried out such that the floating body in a manner floating on the liquid is freely movable, that he expected all

Changes in the fluid level can follow.

The switch can be actuated in this case by the movement of a functional body, wherein the functional body is preferably arranged in the interior of the floating body and is in operative connection with the floating body. This means that the functional body either indirectly or directly to a movement of the float, in particular a

Position or position change of the float, reacts with a corresponding movement. In other words, the movement of the functional body is analogous to the movement of the body

Float directly or indirectly from the

Liquid level or by a change in the

Fluid levels dependent. In the case of an inclined plane following, as

Functional body serving ball, the switch is triggered indirectly by a movement of the float, namely by a by the movement of the float

caused movement of the ball arranged in the float. However, it can also be provided a switch which is triggered directly by the movement of the float. For example, the float can actuate the switch via a linkage or else the floating body is provided with a permanent magnet whose magnetic field actuates a reed contact arranged on the retaining element.

In a further advantageous embodiment of the invention, the functional body actuating the switch is at the same time that functional body whose kinetic energy is converted by an energy converter into electrical energy for supplying the radio transmitter. The energy for operating the radio transmitter is in other words from the

Switching event itself won. This is in principle with all described types of switches and

Energy supply facilities of the case. For example, the switch may have a piezo element such that a ball serving as a functional body running on a defined path of movement changes when the inclination of the ball is changed

Float and a resulting actuation of the switch at the same time generates that electrical voltage that is needed to send the switching signal over the radio link. The piezoelectric transducer is preferably designed such that already a single operation of the

Piezo elements, so here, for example, a single

Switching operation, sufficient to connect the radio transmitter with the

to supply the required electrical energy. The present invention is not limited to the use of a ball actuated microswitch.

Instead of such a switch, various other switches may be used with the present invention.

Instead of a conventional, mechanically actuated

Switch, whose operation is due to a mechanical movement of a functional body, such as a ball, takes place, the movement is related or caused by a change of

Fluid levels and associated movement of the float, allows the proposed wireless

Transmission of the switching signal and in particular the

Energy supply device according to the invention for supplying the radio transmitter with electrical energy derived from the movement of the floating body and the problem-free

Application of electrically or electronically realized switches for outputting a switching signal. These switches are preferably with an electrical or electronic

Sensor for monitoring the fluid level combined and can form a structural unit with this and the radio transmitter. Such an electrical or electronic sensor, the liquid level or a change of the

Detect fluid levels. For example, it may be a miniaturized position sensor or acceleration sensor, as used in smartphones to detect the orientation of the device. Such sensors are often equipped with piezoelectric sensor elements or constructed as MEMS (micro-electro-mechanical system). Since parts of such a sensor can serve as electrokinematical energy converters, a combination with the energy supply device according to the invention can also be provided in this case be. In other words, the energy supply of the

Wireless sensors by the operation of the electrical or

be ensured electronic sensor.

Of course, it is also possible with the use of electrical or electronic sensors and switches, the

To ensure energy supply, as described above, by the movement of the float.

An embodiment of the invention will be explained in more detail with reference to the drawings. The invention is exemplary of a monitoring device for the

Container described a sewage treatment plant. However, this does not limit the invention. As already indicated above, the invention can also be used for monitoring the liquid level in different containers or applications. In the description below:

1 shows a container with a liquid and a

Monitoring device,

Fig. 2 different positions of a floating body, a device for monitoring a

Fluid levels, a section through a linear generator.

The figures show the invention in part schematically simplified or only with their essential

Ingredients. The same reference numerals correspond to it

Elements of equal or comparable function. In a container 2 filled with a liquid 1 a sewage treatment plant, a monitoring device 3 for monitoring the level 4 of the liquid 1 is arranged, see Fig. 1. The monitoring device 3 comprises a float 5 for placement on the liquid 1, one arranged in the float 5 Switch 6, which is used to output a switching signal as a function of the level 4 of the liquid. 1

is formed and arranged in the float 5 radio transmitter 7 for wireless transmission of the switching signal to a arranged outside the float 5 receiver 8, a central control unit of the sewage treatment plant, see Fig. 1 and 3. The floating body 5 is using a

Retaining element in the form of a flexible, rotatably mounted holding rod 9 attached to a stationary holding point 10 on a wall 11 of the liquid container 2, so that a

Changing the liquid level 4 has a change in the inclination of the floating body 5 result, see Fig. 2.

The switch 6 is designed as a changeover switch with a normally closed and a normally open microswitch, the (not shown) via a lever system as a

Function body serving ball 12 is actuated. In

Depending on the inclination of the floating body 5, more precisely, whenever the floating body 5 floating on the liquid 1 is in an upper position,

corresponding to a first liquid level la, or in a lower position, corresponding to a second one

Liquid level lb, the ball 12 changes its position on a predetermined trajectory and actuates the switch 6. This is just one of many possibilities of implementing a switch, as it can be used with the present invention. One arranged in the float 5

Power supply device 13 includes a

electromechanical transducer 14 for converting kinetic energy of the float 5 into electrical energy for

Supply of the radio transmitter 7. The energy obtained in this way is stored in a buffer 15, which is electrically connected to the energy converter 14 and the

Radio transmitter 7 is connected. The energy converter 14 is designed as a linear generator and comprises, as in FIG. 4

shown, a cylindrical permanent magnet 16 which is suspended in a hollow cylindrical guide 17 between the spring elements 18 on the walls of the floating body 5 and can swing in this guide 17 to its rest position. Around the guide 17 around a cylindrical coil 19 is arranged. By a movement of the magnet 16 relative to the electric coil 19 is by electromagnetic induction

generates electricity. The suspension of the magnet 16 in the float 5 is realized so that at each movement of the float 5, but in particular during an up or down movement of the float 5 due to a change in the liquid level 4 or due to a wave motion of the liquid 1, generates electricity and stored in the cache 15. In a further embodiment of the invention, not shown, the energy converter 14 is a piezoelectric transducer

used, the piezoelectric element for generating a

electrical voltage is applied by a functional body with a mechanical force. The piezoelectric element is integrated in such a way in the switch 6 that the

Functional body for actuating the switch 5 serving ball 12 at the same time the functional element for actuating the

Energy converter 14 is. In other words, the energy to operate the radio transmitter 7 from the switching event obtained the same.

All features illustrated in the description, the following claims and the drawings can be used individually as well as in any combination with one another

be essential to the invention.

LIST OF REFERENCE NUMBERS

1 liquid

2 containers

3 monitoring device

4 liquid level

5 floats

6 switches

7 radio transmitters

8 receivers

9 holding staff

10 breakpoint

11 container wall

12 ball

13 energy supply facility

14 energy converters

15 temporary storage

16 permanent magnet

17 leadership

18 spring element

19 solenoid

Claims

claims

A device (3) for monitoring a fluid level (4), comprising a floating body (5), with one in the

Float (5) arranged switch (6), which switch (6) for outputting a switching signal in dependence on the level (4) of the liquid (1) is formed,

characterized by a radio transmitter (7) for wireless transmission of the switching signal to one outside the

Float (5) arranged receiver (8).

2. Device (3) according to claim 1, characterized by means (13) for supplying the radio transmitter (7) with the movement of the floating body (5) obtained electrical energy, comprising an electrically connected to the radio transmitter (6) energy converter (14 ).

3. Device (3) according to claim 2, characterized in that the energy supply device (13) has a with the energy converter (14) electrically connected energy storage (15).

4. Device (3) according to claim 2 or 3, characterized

characterized in that the energy supply device (13) has a linear generator (14), which preferably has an electric coil (19) and a magnet (16) moving during a movement of the floating body (5) relative to the coil (19).

5. Device (3) according to claim 2 or 3, characterized

characterized in that the energy supply device (13) has a piezoelectric transducer (14) and a functional body (12) for actuating the piezoelectric transducer (14), which Piezo transducer (14) preferably has a piezoelectric element, which is designed for generating an electrical voltage, when during a movement of the floating body (5) of the

Functional body (12) on the piezoelectric element with a

mechanical force acts.

6. Device (3) according to one of claims 2 to 5, characterized in that the switch (6) is a mechanical

actuatable switch is.

7. Device (3) according to claim 6, characterized in that the switch (6) by the of the liquid level (4) or a change in the liquid level (4) dependent movement of one with the floating body (5) in operative connection, preferably in Inside the floating body (5) arranged functional body (12) is actuated.

8. Device (3) according to claim 7, characterized in that the energy supply device (13) has a

Energy converter (14) which detects the movement of this

Functional body (12) uses for energy.

9. Device (3) according to one of claims 1 to 5, characterized in that the switch (6) is an electrical or electronic switch.

10. Device (3) according to claim 9, characterized by a device for supplying the radio transmitter (7) with electrical energy obtained from the operation of a

Switch (6) actuated or the switch (6) for outputting the switching signal-bringing sensor, in particular a position and / or acceleration sensor, which sensor is designed to determine the liquid level or to determine a change in the liquid level.