DE102010026087A1 - Method for operating submerged pump arrangement in lifting system, involves deactivating switching function after pumping pump arrangement, and activating switching function after recognizing of reduction of filling level - Google Patents

Abstract

The method involves monitoring achieving of upper filling level threshold (h1) and an upper filling level threshold (h2) for derivation of signals. The former upper filling level threshold lies under the latter upper filling level threshold. The derivation is implemented, during achieving of the latter upper filling level threshold and activation of switching function of the former filling level threshold. The switching function is deactivated after pumping a pump arrangement, and activated after recognizing of reduction of a filling level, without operating the pump arrangement. Independent claims are also included for the following: (1) an electrode module for a filling level sensor (2) a base body for an electrode module (3) a circuit module for a filling level sensor (4) a base body for a circuit module (5) a capacitive filling level sensor that comprises a shrink hose (6) a ballast for implementing a method for operating a pump arrangement.

Description

The invention relates to a method for operating at least one pump arrangement, for. B. a submersible pump assembly of a lifting system with a sensor for level monitoring and an evaluation and control circuit according to the preamble of claim 1 or 6, a level sensor with electrode and circuit module for performing such a method and a use of a capacitive level sensor in a pump system with one or more Electromotive suction pumps, in particular a lifting system.

From the EP 1 629 257 B1 For example, a method and a circuit for detecting a level of a liquid is previously known.

According to the object there, a simple method for detecting a filling level of an electrically conductive liquid in a container with a filling level measuring electrode and a second electrode is to be specified.

In the previously known method, in a first step, a predetermined voltage is applied to a capacitor whose first end is connected to the level measuring electrode and whose second end is connected to the second electrode for a first time period. Thereafter, in a second step, a second time period is waited for and in a third step the voltage on the capacitor is detected. A measuring cycle consisting of the first, second and third step is only repeated if a certain period of time has elapsed after the third step. This should have the advantage that the liquid whose level is to be measured, practically is not electrolyzed, since the time span used for the measurement consists of a short voltage pulse.

In the sensor element of the capacitance measurement and the device for determining the level of a medium with such a sensor element according to DE 10 2004 038 253 B4 is assumed by an electrode assembly consisting of a plurality of juxtaposed and / or successively arranged on a support electrodes. The sensor element can be connected to a measuring device, specifically for measuring the capacitance between at least one electrode and at least one counterelectrode. The after DE 10 2004 038 253 B4 provided support is separated by a separating element of a surrounding the sensor element medium, which is the subject of the capacitance measurement. The separating element is formed from at least ceramic components having material and impermeable to the surrounding medium. In addition, the separating element has a hydrophobic and / or oleophobic coating on its surface facing the surrounding medium.

Furthermore, after DE 10 2004 028 253 B4 a controllable switching device for predeterminable switching and connecting the electrodes as the first and second electrodes with the measuring device and downstream of the measuring device evaluation, which determines the actual fill level from the capacitance measured by the sensor element by comparison with stored reference values. One of the electrodes of the electrode arrangement can be switched as measuring electrode, at least one of the further electrodes as counter-electrode to a predeterminable reference potential.

In addition, lifting systems with submersible pumps are known. On or in the related pump assembly level sensors are located to trigger the pumping operation. After the pumping out of the liquid, the pump is put out of operation.

If, for safety reasons, several pumps are to be provided, problems arise in coordinating the operation of the pumps. Either both pumps are operated in parallel, which is not necessary in itself, or a reserve pump is quasi constantly out of service and is only activated when a certain critical level has been exceeded, which is a signal for insufficient pumping capacity of the primary pump. However, there is a risk that the switched reserve pump fails because of their long non-commissioning.

From the foregoing, it is therefore an object of the invention, a developed method for operating at least one pump assembly, for. B. a submersible pump assembly of a lifting system with a sensor for level monitoring and an evaluation and control circuit indicate that allows a quasi-alternating operation of the pump assembly, especially in multiple pumps without a complex higher-level control unit for coordinating the operation of the individual pumps is required. This should also create the possibility of retrofitting existing lifting systems with a second pump.

In addition, it is an object of the invention to provide a level sensor with electrode and circuit module for performing such a method, said level sensor is part of the sensor for level monitoring and based on a capacitive mode of operation should allow a very high reliability at low cost.

The object of the invention is achieved on the method side with a gauge as defined in claim 1 or 6 and with an electrode module for a level sensor, a corresponding circuit module, primitives for the electrode module and the circuit module and a capacitive level sensor realized in this way with at least one electrode module and at least one circuit module.

According to the invention, moreover, the use of the proposed capacitive level sensor in a pump system with one or more electromotive suction pumps, in particular a lifting system, with an evaluation and control circuit is provided with an operation according to the inventive method for each pump assembly of the pump system, without it it is necessary to combine discrete evaluation and control circuits in a higher-level circuit unit.

It is therefore assumed that a method for operating at least one pump arrangement with a sensor for level monitoring and an evaluation and control circuit.

According to the invention, according to a first aspect, the achievement of a first h1 and a second h2 upper level threshold for deriving signals for the control of the pump assembly is monitored, wherein the first upper level threshold h1 is below the second upper level threshold h2 such that upon reaching the second upper level threshold h2 always a pumping is initiated. On the other hand, when the first upper level threshold h1 is reached, pumping is only initiated when the switching function of the first upper level threshold is active. After initiating the pump down, the switching function of the first upper level threshold h1 is deactivated and activated after detecting a reduction in the level without operation of the pump assembly. The sensor system monitors the achievement of the first h1 and the second h2 fill level threshold for deriving a switch-on signal, namely a first switch-on signal Sh1 and a second switch-on signal Sh2 for the pump, with the pump being switched on by the first or second switch-on signal Sh1, Sh2 is latched until it reaches a predetermined termination criterion. The termination criterion may be an exceeding of a certain period of time or else a switch-off signal Sh0.

The switch-off signal Sh0 can be generated by reaching a third fill level threshold h0, which lies below the first fill level threshold h1, or by exceeding a minimum value Sdmin, a difference of a fill level signal, which represents a decrease in the fill level.

Upon reaching the first level threshold h1, the turn-on signal Sh1 generated thereby switches on the pump P1. With or after this switching on, at the latest until this pump P1 is switched off, the same is blocked for a renewed switch-on signal Sh1, until the presence of a further active pump P2 can be concluded by determining the minimum value of the pumping rate and the sinking of the liquid level with the pump switched off such that alternately turn on both pumps.

As long as the aforesaid minimum value is not determined, either the pump is periodically or alternately blocked for being switched on by the first switch-on signal Sh1, or the blocking is carried out permanently at least until the minimum value Sdmin has not been reached.

According to the invention, according to a second aspect, for. B. for calibration purposes, the achievement of a first and a second upper level threshold monitored, wherein the first upper level threshold is below the second upper level threshold.

Capacitive level sensors are used for monitoring the level thresholds, which are explained in detail below.

At start-up or at predetermined intervals, the pump assembly is activated upon reaching the first upper level threshold and it is pumped out until it reaches a lower, usually minimal level threshold.

After that, a deactivation of the detection of the first level and a permanent activation of the detection of the second level threshold is initiated.

Furthermore, after the recognition of the re-reaching of the lower, minimum fill level limit without operation of the quasi-primary pump arrangement, a conclusion can be drawn on a foreign pumping process. As a result, a renewed activation of the first, upper fill level threshold occurs analogously to the startup.

If a further pump arrangement is provided with its own sensor for level monitoring and evaluation and control circuit, which operates independently of that of the first pump arrangement, is for a setting or specification of the first upper level threshold this further pump arrangement care taken, which differs from the level of those first upper level threshold of the first pump assembly. The first upper fill level threshold of the second pump arrangement may be selected larger than the first upper fill level threshold of the first pump arrangement.

When the detection of the first upper fill level threshold of the first pump arrangement is deactivated and the fill level rises again, the second pump arrangement is put into operation upon reaching the first upper fill level threshold and deactivation of the first upper fill level threshold of the second pump arrangement is carried out with the pumpdown process performed, such that an alternating operation of the second pumping arrangement occurs otherwise independent pump arrangements becomes possible.

An electrode module according to the invention for a filling level sensor, in particular for use in a method of the preceding description, is based on a carrier body and at least one surface electrode disposed thereon and an electrically insulating sheath.

According to the invention, the carrier body is designed as a hollow profile body and receives in the cavity electrical connection means, in particular electrical connection wires or connection conductors.

In the hollow profile body at least one, a connecting wire receiving connecting channel is arranged, which, starting from the cavity and the module longitudinal axis deviates from the right angle, preferably acute angle, to the outer surface of the hollow profile body.

A conductive end of the connection wire exits from the connection channel on the outer surface and is contacted there with the actual surface electrode.

For contacting the surface electrode can be wound on the hollow profile body.

In a preferred embodiment, the surface electrode consists of a self-adhesive, metallic foil.

Ausgestalt are arranged on the hollow profile body in the longitudinal direction spaced surface electrodes. The hollow profile body may have a cylindrical cross section and in particular the sheath may be formed as a shrink tube.

In one embodiment, it is possible to provide the profile hollow body with a reference electrode that is not electrically insulated from the outside.

However, an embodiment in which the reference potential of the level measurement is coupled only to the protective earth of the pump is particularly preferred. In this case, a reference potential electrode at the lower level sensor, also denominated as a bottom electrode omitted.

The profile hollow body has an opening for the connection means feed, in turn, at a further development at a longitudinal end, wherein a connecting section is formed in the region of the opening. This connecting portion can be designed as a screw thread.

A main body for the above-described electrode module is formed as a hollow profile body with at least one-sided access for receiving electrical connection means, wherein between the cavity and the outer surface at least one connecting channel is present, the course of which differs from the oriented to the longitudinal axis of the profile hollow body perpendicular.

The main body may include an enlarged cavity for receiving a wiring substrate of an electronic circuit. This electronic circuit may be formed as an oscillator circuit, but also include elements of the evaluation and control circuit.

The circuit module according to the invention for a level sensor with a carrier body, in particular for a method as explained above, has a carrier body, designed as a hollow profile body, wherein received in the cavity a wiring substrate with electrical circuit and the cavity electrical circuit means, in particular electrical wires or conductors are performed.

In the hollow profile body at least one, a connecting wire receiving connection channel is formed, which, starting from the cavity and the module longitudinal axis deviates from the right angle to the outer surface. A conductive end of the lead wire exits the connection channel on the outer surface and is contacted there with a surface electrode to be mounted on the profile hollow body. This surface electrode can also be formed as a winding electrode.

At one end of the hollow profile body, a connecting portion can be formed, which may be a threaded portion.

At the opposite end of the connecting portion of the hollow profile body means for moisture-proof management of electrical connections are provided.

The hollow profile body may be formed as a hollow cylinder or similar elongated hollow body.

In the base body for the above-described circuit module, this is also designed as a hollow profile body with longitudinal passage openings for receiving a wiring substrate of an electronic circuit and with a connecting portion, wherein between the longitudinal passage opening and the outer surface extends a connecting channel for an electrical conductor.

The elements described above, namely the circuit module and the electrode module, represent a capacitive level sensor, wherein the electrical connection between the electrode module and the circuit module is possible via an integrated plug-socket solution in the arrangement.

The assembled overall arrangement of the capacitive level sensor is surrounded and sealed by a common, thin-walled, electrically insulating wrapping material, in particular the already mentioned shrink tubing.

With a single of the surface electrodes, both different fill level thresholds as well as time courses can be determined, which is advantageous for carrying out the method.

The method can also be realized with two, in the longitudinal direction with respect to the module spaced electrode surfaces.

With two sensors each having an electrode surface, a sensor may be provided as a sensor for monitoring the upper fill level threshold or thresholds, and the lower sensor may be provided as a ground sensor or sensor for monitoring the minimum fill level limit.

A double sensor may be formed as a variant that allows use as a top level sensor with a small gap between the electrodes and at a large distance is a unit located on top of a bar-like structure as both top and bottom level sensors.

According to the invention, moreover, the use of the proposed capacitive level sensor in a pump system with in particular a plurality of electromotive suction pumps, in particular a lifting system, wherein for each pump arrangement of the pump system an evaluation and control circuit is provided with an operation according to the above-described method.

The invention will be explained in more detail with reference to embodiments and with the aid of figures.

Hereby show:

1 a basic arrangement of a sensor for level monitoring within a lifting system with submersible pump P;

2 a representation similar to that after 1 but with the arrangement of two pumps P1 and P2 and respectively associated condition monitoring sensors with the aim of achieving alternating operation of the pumps P1 and P2;

3 a program flow chart for explaining the operation and the control of the pump assembly;

4 a principal time course of the activities of the pumps P1 and P2 as a function of the level FS over time t;

5 a schematic sectional view of a capacitive level sensor, which is located in a vessel with liquid;

6 a schematic diagram of a level sensor whose electrode module has two sensor electrodes, and with an indicated circuit module;

7 a waveform of the first and second signal outputs S1 and S2 as a function of the level h with reference to the 6 ;

8th a longitudinal section through the electrode module according to the invention;

9 a cross section along the line VV with recognizable wound sensor electrode according to 8th ;

10 an electrode module with two sensor electrodes in a perspective view;

11 a perspective view of the circuit module according to the invention with a recognizable board having electronic components;

12 an illustration of a level sensor, comprising electrode module and Circuit module with their provided on both modules surface electrodes in longitudinal section view;

13 an electrode module, particularly suitable for the determination of a lower filling level with only a single sensor electrode and complementary reference potential electrode, which leads in the longitudinal direction to the outside, in longitudinal section;

14 a submersible pump with inventive capacitive level sensor or more of these sensors, connected to a ballast;

15 a cross section along the line XI-XI according to 14 with representation of a fastener for the level sensor with respect to a suitable pipe or hose support portion, wherein the fastener as seen in the sectional view, comprises two conical or wedge-shaped recesses and the fixation is made by means of hose band;

16 a schematic diagram of a lifting system with level sensor in capacitive embodiment according to the invention, electric motor M and main pump P;

17 a preferred oscillator circuit for operating the sensor system according to the invention and

18 a preferred measuring circuit according to the invention, which generates a level-dependent output signal S, starting from the alternating current acting on the surface electrode.

In the representations after the 1 and 2 is assumed by a basic arrangement of a pump P or a first pump P1 and a second pump P2 in a vessel, in particular a collecting vessel of a lifting plant.

In addition, level sensors are available in the vessel.

A lower level sensor FSU determines a minimum level h0 level.

An upper level sensor FSO is able to determine two level thresholds.

Specifically, the upper level sensor FSO can determine a first upper level threshold h1 and a second upper level threshold h2.

The housing of the level sensors FSU and FSO preferably consists of a round rod, on which a circumferential metallic surface is applied. The metallic surface is covered with an electrically insulating layer.

The electrically conductive layer communicates with evaluation electronics via indicated cables.

In known manner takes place via the connecting line, a power supply and signal transmission.

In the example shown after 1 and 2 The lower level sensor FSU dips into a grounded or grounded liquid.

The current flowing from the corresponding electrode into the grounded liquid is monitored by evaluation electronics, not shown, and output as a filling level signal S. The magnitude of the current here is essentially proportional to the wetted electrode area, indicated by the diagonally hatched representation of the sensors FSU and FSO.

Details of the structure of the preferred capacitive level sensors are recourse to the 8th to 13 explained.

The 2 shows an arrangement in which in addition to the pump P1 in the pump sump area, a second pump P2 is arranged with its own level-based pump control.

If the liquid level rises, either the first pump P1 or the second pump P2 is switched on, depending on the leveling of the upper level sensors FSO and FSO '.

I'm in the 2 In the case shown, the upper sensor FSO 'of the second pump P2 is slightly higher than the upper sensor FSO of the first pump P1, so that when the level rises, first the first switching threshold h1 of the first pump 1 is reached. The lower level sensors FSU, FSU 'for the pumps P1 and P2 have a different level h0, h'0.

After pumping through the first pump P1, the first switching threshold h1 of the first pump P1 is deactivated, while the first threshold h'1 of the second pump P2 is still active.

When the liquid level rises again, after the first switching threshold h'1 of the second pump P2 has been reached, the second pump P2 is switched on and the first switching threshold h'1 of the second pump P2 is deactivated.

The pumping process is monitored via the lower sensors FSU and FSU 'of the pumps P1 and P2 and, if appropriate, a shutdown of the respective pump P1 or P2 is triggered.

When the liquid is pumped out by the second pump P2, a sinking rate is also registered at the lower sensor FSU of the first pump P1. However, since the first pump P1 was not in operation, this Absinkrate is recognized as a foreign Abpumpvorgang.

According to the invention, it is now provided after a recognized foreign Abpumpvorgang to activate the first switching threshold h1 of the first pump P1 again.

This predefinition ensures that an alternating operation occurs without additional external connection of the two pumps P1 and P2.

3 shows a related flowchart as a program flowchart and 4 a time course of the activities of the pumps P1 and P2 depending on the level reached in each case.

If the power of one of the pumps P1 or P2 is insufficient and the fluid level continues to increase in the event of an excessive amount of fluid, the second switching source h2 or h'2 of the respective other pump is reached after some time, which then switches on.

It is accordingly a central basic idea of the invention to provide preferably for existing pump systems a sensor system which enables safe and reliable operation.

One of the focal points is the detection of a two-pump or multi-pump system based on level signals and a method for uniform utilization of the respective pumps on the basis of the detected level signals.

To implement the method, a control device or a ballast and a corresponding fill level sensor arrangement, as already explained above, are provided on the device side.

To control the switching on and off of the pumps P1 and P2 or P is in the 1 and 2 not shown ballast provided, which is in communication with the corresponding level sensors FSU and FSO.

The upper level sensor FSO or FSO 'monitors a first and a second level switching threshold h1, h2 or h'1 and h'2, while the respective lower level sensor FSU or FSU' primarily serves for detecting the pumping rate. Of course, at the lower sensor FSU or FSU 'and a shutdown h0 be monitored.

It is inventively provided that the first level threshold h1 is activated only temporarily or alternately, while the upper second level switching threshold h2 is permanently active.

When the system is first put into operation, the liquid level reaches the first level h1 in accordance with 1 , so the pump P is turned on and at the same time the first level threshold h1 activated.

The pumping is now time-controlled and / or until reaching a lower level h0.

When the liquid level rises again, due to the deactivated first switching threshold h1 or h'1, the respective pumps then only switch on at the second switching threshold h2 or h'2. Without renewed activation of the first switching threshold h1 or h'1, the respective pump P1 or P2 is now regularly switched on only at the second switching threshold h2 or h'2.

The basic structure of the preferably used sensors for level monitoring is in the 5 to 7 shown.

As already indicated, the sensor housing has a round rod 1 on, on a circumferential metallic surface 2 is applied as a surface electrode.

This surface electrode 2 is from an electrically insulating layer 3 covered.

The electrically conductive layer 2 , ie the surface electrode, communicates with electronics.

Via the connecting lines V + and V- corresponding potential is supplied.

The output signal S is passed through a further line to the outside.

In the example shown 5 the level sensor immerses in a partially grounded liquid 4 a, which is in a vessel 5 , z. B. a lifting plant is located.

The of the surface electrode 2 into the grounded liquid 4 flowing current is monitored by an evaluation and output as the aforementioned level signal S. The magnitude of the current is essentially proportional to the indirectly wetted area of the surface electrode 2 ,

The 6 shows a level sensor with an electrode module 6 , the two surface electrodes 2 with appropriate insulating layer 3 has.

A circuit module 7 includes a first evaluation 8th and a second transmitter 9 , One of the evaluation electronics 8th or 9 is with a surface electrode 2 communicating. On the output side are thus signals S1 and S2 with respect to the respective surface electrodes 2 made available.

Power is supplied via common lines V + and V-.

7 shows a signal curve S, the at the signal outputs S1 and S2 according to the schematic representation according to 6 is applied, depending on a level height h, in particular h1, h2, h3 and h4.

The level signals can be output here, for example, in a voltage range of 0 to 10 V.

Preferably, in a non-applied liquid no 0-volt signal is output, but a lower, defined voltage value, for. B. 0.1 V.

If the liquid rises from the level h1 to the second level h2, the signal voltage output by the first electronics also increases proportionally to the fill level and reaches a maximum with the fill level h2 and remains constant there.

If the third level h3 is exceeded, the level signal of the second area electrode also increases 2 until the maximum measurable fill level h4 is reached there as well.

The distribution of the fill levels to be measured on two sensor surface electrodes has the advantage that the fill level resolution, which is divided with an electrode to the levels between h1 to h4, can be used twice in the levels h1 to h2 and h3 to h4 and thus one Improvement is subject.

Details of an electrode module will become apparent from the following explanation, in particular the 8th to 10 ,

8th shows a longitudinal section through an inventive electrode module 6 and 9 a corresponding cross-section.

The electrode module 6 for a level sensor is based on a hollow profile body 10 out in the cavity 11 Connection means, in particular electrical connection wires 12 receives.

In profile hollow body 10 is at least one, a connecting wire 12 receiving connection channel 13 arranged, which starting from the cavity 11 and the module longitudinal axis, deviating from the right angle, preferably at an acute angle, to the outer surface of the hollow profile body 10 runs.

A leading end 14 of the connecting wire 12 exits the connection channel 13 on the outer surface and is there with the surface electrode 2 contacted.

For contacting is the surface electrode 2 on the profile hollow body 10 wound up, wherein the surface electrode 10 can consist of a self-adhesive metallic foil.

Like in the 8th recognizable, is on the profile hollow body 10 in the longitudinal direction spaced the formation of two surface electrodes 2 intended.

The hollow profile body 10 has, as in the cross-sectional view 9 recognizable, a cylindrical configuration and it is an outer sheath, preferably as a shrink tube 15 , available.

The thickness of the shrink tubing 15 should be as low as possible and constant over its longitudinal course.

The distance A between the two surface electrodes 2 on the profile hollow body 10 should be in the range ≥ 5 mm.

The web formation of the connection channel 13 allows in each case a very easy insertion of the corresponding connection wire 12 with its conductive end 14 and thus a very advantageous, less time-consuming installation.

The conductive ends 14 the connecting wires 12 are reaching into the overlapping area of the wound surface electrode.

10 shows an electrode module 6 according to the above description in perspective view.

The surface electrodes are also wound here as metallic adhesive films around a base body.

The surface electrodes are contacted via stranded cable and as a socket part 16 a connector led to the outside.

The open side of the central hole in the hollow profile body 10 of the electrode module 6 is with the socket part 16 completed.

11 shows a perspective view of a circuit module according to the invention 7 in an exploded view.

The circuit module 7 in turn has a carrier body, which is used as a hollow body, for. B. as a hollow cylinder 17 is trained.

In the cavity of this hollow cylinder 17 is a wiring support 18 can be arranged. The wiring carrier 18 picks up an electrical circuit that includes elements of the drive and / or evaluation circuit or can also display this completely.

About the cavity electrical connection means are guided. In particular, the wiring carrier is 18 with a plug part 19 in conjunction with the socket part 16 of the electrode module 6 comes into contact.

The output signal lines 20 Become a standard sealing fitting 21 led to the outside.

An end-side section of the hollow profile body 10 of the electrode module 6 has an external thread 22 on, an internal thread 23 in the hollow body 17 is complementary.

The for the sealing screw connection 21 pointing end of the hollow body 17 of the circuit module 7 is also provided with an internal thread, which on the external thread 24 the sealing screw connection 21 is agreed.

Of course, it is possible instead of an output cable connection guide 25 also to arrange a standard plug or a standard socket or the like means.

12 shows a sectional view of a not yet screwed electrode module 6 with a circuit module 7 ,

Here, in distinction to the representation 11 the circuit module 7 also a separate surface electrode 2 on.

The next presentation after 13 discloses an electrode module 6 with surface electrode 2 and insulating cladding 3 , wherein at an end, from the arrangement area of the female part 16 remote, opposite end an outwardly guided reference potential electrode 26 is located.

This reference potential electrode 26 also communicates with one of the leads and connects to a contacting portion within the socket 16 guided.

The 14 shows a schematic diagram of a submersible pump 27 with liquid discharge hose 28 and an arrangement of two level sensors according to the invention as a lower level sensor FSU 29 and upper level sensor FSO 30 , The outputs of the level sensors 29 and 30 lead to a ballast 31 that with a power outlet 32 communicates. The ballast can additionally be connected to a flow switch.

About the solution of a fastener after 15 (Representation along the line XI-XI according to 14 ) can the corresponding level sensor 30 or 33 at a coupling section 34 in which the hose 28 is fixed, fixed.

For example, comes as a connection and Arretierungskörper 35 a double conical or double prismatic or similar shaped fastener is used, which has a through hole 36 owns, each a cable tie 37 or the like can take fixative. This simple technological solution allows the desired retrofitting of existing submersible pumps with the level sensor according to the invention.

The schematically shown in section. Lifting system after 16 includes a fluid receptacle 40 , In the vessel 40 there is the submersible pump P, which is from one above the vessel 40 driven motor M is actuated.

A screw cap 41 on the vessel 40 allows the fixing of a level sensor according to the invention, such as in the 12 shown. The pump suction area, the liquid discharge area and the liquid supply are each symbolized by arrow representations.

If according to the illustration 16 the pump housing is made metallic or has conductive elements and as usual is at ground potential, a separate reference electrode can be omitted at the level sensor, wherein the reference electrode is made via the mains ground, if and so far from the vessel 40 Conductive liquids are added.

The oscillator circuit according to 17 will be described below.

The switching arrangement according to 17 goes from a Vienna-Robinson oscillator as possible Signal source for the evaluation and control circuit of the invention.

The frequency of the oscillator is determined in a manner known per se by a first RC element R1 / C1 and a second RC element R2 and C2, the amplitude being defined by the anti-parallel connected diodes D1 and D2 and the resistors R3 and R5.

The operating voltages for the operational amplifier OPV and the actual oscillator are provided via a connected in series with the Zener diodes Z1 and Z2 resistor R5 and corresponding voltage tap.

The supply voltage U _V is preferably in the range between 10 and 30 V.

The capacitor C3 serves to suppress parasitic oscillations in the following operational amplifier. At the output _terminals is the oscillator _{AC voltage} U _osz .

The 18 shows, by way of example, a measuring circuit for evaluating the alternating current flowing across the respective electrode EL.

The circuit is based on the principle according to which the current flowing to the electrode EL is detected as a voltage drop across a measuring resistor RM from an operational amplifier OP2 connected as a differential amplifier and provided as a DC voltage signal via a full-wave rectifier D3, D4 to a DC voltage amplifier OP3.

The DC amplifier OP3 supplies at its output the signal voltage U _S , preferably in a voltage range between 0 and 10 V.

In order not to burden the current flow C2 to the electrode EL, the voltage tap on the measuring resistor RM via the switched as an impedance converter operational amplifier OP1.

The operational amplifier OP2, which is connected as a differential amplifier, is connected on the input side via dimensionally matched resistors R10, R11 and R20 and R21 which are preferably of the same value in terms of value.

The operating voltage is taken via the series resistor RV of the supply voltage U _V and stabilized via a cascade of Zener diodes Z3 and Z4 to preferably 5.4 V.

LIST OF REFERENCE NUMBERS

P, P1, P2

pump

A

distance

FSU

lower level threshold

FSO

upper level threshold

1

round bar

2

surface electrode

3

insulating layer

4

liquid

5

vessel

6

electrode module

7

circuit module

8th,

9 evaluation

10

Hollow profile

11

cavity

12

Lead wire

13

connecting channel

14

leading end

15

shrinkable tubing

16

female connector

17

hollow body

18

wiring support

19

plug part

20

Output signal line

21

Abdichtungsverschraubung

22

external thread

23

inner thread

24

External thread of the sealing screw connection

25

Output cable guide

26

Reference potential electrode

27

submersible pump

28

tube

29, 30, 33

level sensor

31

ballast

32

socket

34

coupling section

35

connecting body

36

Through opening

37

cable ties

40

Lifting installation vessel

41

screw cap

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1629257 B1 [0002]
• DE 102004038253 B4 [0005, 0005]
• DE 102004028253 B4 [0006]

Claims (23)

Method for operating at least one pump arrangement with a sensor for filling level monitoring and an evaluation and control circuit, characterized in that the achievement of a first (h1) and a second (h2) upper level threshold for deriving signals for the control of the pump assembly is monitored, the first upper level threshold (h1) below the second upper level threshold (h2) is such that when the second upper level threshold (h2) is reached, pumping is always initiated, whereas upon reaching the first upper level threshold (h1) the discharge is only initiated, when the switching function of the first upper level threshold is active, and that after initiation of the pump down, the switching function of the first upper level following (h1) is deactivated and activated after detecting a reduction in the level without operation of the pump assembly. A method according to claim 1, characterized in that the sensor monitors the achievement of the first (h1) and the second (h2) level threshold for deriving a first switch-on signal (Sh1) and a second switch-on signal (Sh2) for the pump, wherein with the switching on Pump by the first or second switch-on signal (Sh1, Sh2) the pump is latched until it reaches a predetermined termination criterion and wherein the termination criterion may be the exceeding of a certain period of time or a switch-off (Sh0). A method according to claim 2, characterized in that the switch-off signal (Sh0) by reaching a third level threshold (h0), which is below the first level threshold (h1) or by exceeding a minimum value (Sdmin) of a difference of the level signal, which a decrease in the Level corresponds, is generated. A method according to claim 3, characterized in that with reaching the first level threshold (h1) the turn-on signal (Sh1) generated thereby turns on the pump (P1) and with or after this switching on, at the latest until switching off this pump (P1) selbige for a renewed switch-on signal (Sh1) is blocked until the conclusion of the minimum value (Sdmin) of Abpumprate and sinking liquid level with pump off (P1) on the presence of another active separate pump (P2) is closed, such that alternately both Switch on pumps (P1, P2). A method according to claim 4, characterized in that as long as the minimum value is not detected, either the respective pump for switching on by the first switch-on signal (Sh1) is periodically or alternately locked or the blocking is carried out permanently. Method for operating at least one pump arrangement with a sensor for filling level monitoring, and an evaluation and control circuit, characterized in that the achievement of a first (h1) and a second (h2) upper level threshold for deriving signals for the pump control is monitored, the first upper level threshold (h1) being below the second upper level threshold (h2), Upon startup, the pump assembly is activated and a significant pumping until a predetermined termination criterion occurs, thereafter deactivating the detection of the first level threshold is provided and continues to be closed after detecting a reduction in the level without operation of the pump assembly to a Fremdabpumpvorgang and as a result activating the first (h1) upper level threshold takes place analogously to the startup. A method according to claim 6, characterized in that a further pump arrangement is provided with its own sensor for level monitoring and evaluation and control circuit which operates independently of that of the first pump arrangement, wherein the setting or specification of the upper level threshold (h'1) from the level that of the first upper level threshold (h1) of the first pump arrangement deviates. A method according to claim 7, characterized in that when deactivated detection of the first upper level threshold (h1) of the first pump assembly and renewed increase in the level of the second pump assembly with reaching the first upper level threshold (h'1) is put into operation and with performed Abpumpvorgang Disabling the first upper level threshold (h'1) of the second pump assembly takes place, so that an alternating operation of the otherwise independent pump assemblies is possible. Method according to claim 7 or 8, characterized in that the levels of the first upper level thresholds (h1; h'1) are below the respective level of the second upper level thresholds (h2; h'2). Electrode module for a level sensor with a carrier body and at least one on this arranged surface electrode and an electrically insulating sheath, in particular for a method according to one of the preceding claims, characterized in that the carrier body is designed as a hollow profile body and selbiger in the cavity electrical connection means, in particular electrical connection wires or connecting conductor receives, wherein in the hollow profile body at least one a connecting wire receiving connecting channel is arranged, which, starting from the cavity and the module longitudinal axis deviates from the right angle, preferably acute angle, to the outer surface of the hollow profile body and a conductive end of the connecting wire exits from the connecting channel on the outer surface and is contacted there with the surface electrode. Electrode module according to claim 10, characterized in that for contacting the surface electrode is wound on the hollow profile body. Electrode module according to claim 11, characterized in that the surface electrode consists of a self-adhesive metallic foil. Electrode module according to one of claims 10 to 12, characterized in that arranged on the hollow profile body in the longitudinal direction spaced surface electrodes. Electrode module according to one of claims 10 to 13, characterized in that the hollow profile body has a cylindrical cross-section and the sheath is formed as a shrink tube. Base body for an electrode module according to one of claims 10 to 14, characterized in that it is designed as a hollow profile body with at least one-sided access for receiving electrical connection means, wherein between the cavity and the outer surface at least one connecting channel is present, the course of which to the longitudinal axis of the profile hollow body oriented vertical deviates. Base body according to claim 15, characterized in that it comprises an enlarged cavity for receiving a wiring substrate of an electronic circuit. Circuit module for a level sensor with a carrier body, in particular for a method according to one of claims 1 to 9, characterized in that the carrier body is formed as a hollow profile body, wherein in the cavity a wiring substrate with electrical circuit added and via the cavity electrical connection means, in particular electrical wires or conductor are guided in the hollow profile body at least one, a connecting wire receiving connecting channel is formed, which extends from the cavity and the module longitudinal axis deviates from the right angle to the outer surface, and a conductive end of the connecting wire from the connecting channel exits on the outer surface and there with a on contacted the profile hollow body to be attached surface electrode. Circuit module according to claim 17, characterized in that the surface electrode is formed as a winding electrode. Basic body for a circuit module according to claim 17 or 18, characterized in that this is designed as a hollow profile body with longitudinal passage openings for receiving a wiring substrate of an electronic circuit and with a connecting portion, wherein between the longitudinal passage opening and the outer surface extends a connecting channel for an electrical conductor. Capacitive level sensor with at least one electrode module and at least one circuit module according to one of claims 10 to 14 and 17 and 18. Capacitive level sensor according to claim 20, characterized in that the assembled overall arrangement of a common, thin-walled, electrically insulating wrapping material, in particular a shrink tube is surrounded and sealed. Use of the capacitive level sensor according to claim 20 or 21 in a pump system with one or more electromotive suction pumps, in particular a lifting system, wherein for each pump arrangement of the pumping system an evaluation and control circuit is provided with a method of operation according to the method of any one of claims 1 to 4. Ballast for carrying out the method according to one of claims 1 to 9, characterized in that this means for processing the output signals of the respective level sensor and for immediate network-side commissioning and switching of the submersible pump assembly has.

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