EP3848578A1 - Pump and odorisation system comprising such a pump - Google Patents

Abstract

The invention relates to a pump (18) for dosing a liquid (12), with (a) a cylinder (20) which has a cylinder interior (22), (b) an armature (26) which is located in the cylinder interior (22) runs and is at least partially ferromagnetic, (c) a first electromagnet (38) and a second electromagnet (40), which together with the armature (26) form a reluctance linear motor, by means of which the armature (26) can be moved in the cylinder (20) is, (d) a pump chamber (48), which can be enlarged and reduced by actuating the armature (26), is connected to a feed line (50) for filling with the liquid to be pumped (12) and a discharge opening (60) for Dispensing the pumped liquid (12), (e) wherein the feed line (50) has an, in particular magnetically, switchable valve (54), and (f) the pump has a position sensor (46) for the contactless determination of an armature position of the Has armature (26) relative to the cylinder (20).

Description

The invention relates to a pump, in particular an odorant pump. The invention also relates to a metering system with a target fluid line and a metering device for metering a liquid to the target fluid.

For example, the metering system is an odorizing device for metering an odorant to a target fluid in the form of natural gas in a target fluid line in the form of a natural gas line.

Natural gas is odorized so that if a leak occurs in the natural gas pipeline, this will be noticed quickly. Odorants are very odorous and therefore only need to be added in very small quantities. This makes it possible to manage with a comparatively small supply of odorant for a long operating time. However, this assumes that the pump requires as little maintenance as possible.

The DE 10 2014 215 110 A1 discloses a linear actuator in which a hydraulic cylinder is hydraulically connected to a solenoid pump. The solenoid pump has a pump coil, a pump armature and a multi-way valve, it being possible for the multi-way valve to be energized together with the pump coil.

The DE 1 088 684 B discloses an electro-hydraulic reciprocator whose pump is driven by an electromagnet.

The U.S. 4,274,407 A relates to a dosing system, in particular for fluids in the dispensing of drugs. A pump and valve device has an electromagnetic generator.

The DE 693 11 525 T2 relates to a pump with a movable magnet in which moving magnet bodies can be made to reciprocate directly electromagnetically.

The DE 199 61 852 A1 relates to a pump for conveying pressure media in controlled braking systems of vehicles. The valves are controlled electromechanically and therefore largely independent of pressure and temperature.

The DE 196 23 162 A1 relates to a solenoid valve with an electromagnetic coil, the armature of which is designed to be stationary, thus bringing about improved dynamics and requiring no seals.

The DE 195 44 029 A1 relates to an electromagnetic oscillating piston pump, the suction opening of which is located halfway up the side of the housing.

The DE 39 33 125 A1 discloses an electromagnetically actuated pump for conveying liquid media with a coil and an armature which serves as a pump piston.

The EP 2 971 902 B1 discloses a mechanically locking solenoid valve.

The invention is based on the object of reducing disadvantages in the prior art.

The invention solves the problem by a pump with (a) a cylinder that has a cylinder interior, (b) an armature that runs in the cylinder interior and is at least partially ferromagnetic, (c) a first electromagnet and a second electromagnet that is connected to the Armature form a reluctance linear motor, by means of which the armature can be moved in the cylinder, (d) a position sensor for the contactless determination of an armature position of the armature relative to the cylinder and (e) a pump chamber that can be enlarged and reduced in size by actuating the armature , is connected to a feed line for filling with liquid to be pumped and has a dispensing opening for dispensing pumped liquid. Preferably (f) the feed line has a magnetically switchable valve.

The invention also solves the problem by means of a generic odorization system in which the odorization device has a pump according to the invention. It is favorable if the odorization device has a reservoir which contains the odorant.

The advantage of the pump is that it can be hermetically sealed. The liquid, in particular the odorant, can therefore only escape from the pump in exceptional circumstances.

To this end, it is particularly favorable if, according to a preferred embodiment, all areas of the pump that come into contact with the liquid, in particular the odorant, form a continuous wall.

It is also beneficial that the pump has a comparatively simple structure. It is thus possible to position the armature by means of the electromagnets, which preferably do not come into contact with the liquid. In this case, undesirable reactions between the liquid, in particular the odorant, and the material of the electromagnet cannot occur.

It is also favorable that the anchor can be made relatively lightweight with comparatively simple means. According to a preferred embodiment, an armature mass of the armature is at most approximately ten percent of the mass of the ferromagnetic material of the magnetic circuit causing the armature movement.

The feature that the electromagnets form a reluctance linear motor with the armature is understood in particular to mean that an oscillating movement of the armature can be brought about by alternately energizing the first electromagnet and the second electromagnet.

The feature that the pump chamber can be enlarged and reduced in size by actuating the armature is understood in particular to mean that the pump chamber is enlarged and reduced in size by moving the armature along a longitudinal axis of the armature becomes. In other words, the liquid can be moved into and out of the pump chamber by moving the armature along its armature longitudinal axis, which causes the liquid to be pumped.

A ferromagnetic material is understood to mean a material that can be magnetized, although it does not have to be magnetized. It is favorable if the armature is soft magnetic where it is ferromagnetic. A coercive field strength of the material of the armature, in particular in the area where it is at least partially ferromagnetic, is preferably at most 1,000 amperes per meter.

Since the armature can be moved within the cylinder by means of the electromagnet, the armature can also be referred to as a piston. The armature preferably has liquid channels through which liquid flows when the armature moves in the cylinder along its armature longitudinal axis.

It is advantageous if the electromagnets are separated from the cylinder interior in a liquid-tight manner. This prevents the electromagnet from being influenced by liquids, in particular odorants, in the cylinder interior.

It is favorable if the feed line runs through the armature. This generally results in a pump that is easy to assemble. It is also beneficial if the feed line connects the cylinder interior with the pump chamber. It is particularly favorable if the feed line connects the pump chamber with the area of the cylinder which is remote from the pump chamber with respect to the ferromagnetic section. If the armature moves in such a way that the pump chamber enlarges, this movement leads to an increased pressure at an inflow opening of the feed line, so that the liquid flows quickly into the pump chamber.

According to a preferred embodiment, the armature has an armature element which is ferromagnetic and which is spaced apart from an inner surface of the cylinder by an annular gap. The anchor preferably also comprises a shaft to which the anchor element is attached. The anchor is preferably on two sides over the anchor element over. It is favorable if the armature is guided in an axial guide at its protruding ends.

The pump is preferably designed to deliver the liquid at a pressure of at least 3 bar, in particular at least 5 bar. The pressure is preferably at most 30 bar, in particular at most 20 bar.

In order to achieve the highest levels of accuracy when metering the liquid, the presence of gas, in particular gas bubbles, in the liquid should be largely ruled out. For this purpose, it is advantageous if the valve can be switched without contact. The valve is preferably magnetically switchable.

According to a preferred embodiment, the magnetically switchable valve has a magnetic valve body. This is understood in particular to mean that the valve can be brought from an open position into a closed position by changing a magnetic field, in particular a magnetic field in which the valve is arranged. In the open position, the valve body is spaced apart from a valve seat so that liquid can flow through the valve. In its closed position, the valve body rests against the valve seat so that the valve is closed.

It is favorable that the valve has a resetting device, in particular a spring, which biases the valve body into the open position or into the closed position. It is then possible and preferred to (i) move the valve from the closed position to the open position by changing a magnetic field applied to the valve, then (ii) energize the first electromagnet so that the armature moves, then ( iii) changing the magnetic field (which previously brought the valve from the closed position to the open position), in particular switching off the magnetic field so that the reset device closes the valve, and then (iv) actuating the armature so that the pump Releases liquid. The controller is preferably designed to automatically carry out a method with the following steps: (i) changing a magnetic field applied to the valve so that the valve comes from the closed position into the open position, then (ii) energizing the first electromagnet so that the Anchor moves, then (iii) changing the Magnetic field (which previously brought the valve from the closed position to the open position), in particular switching off the magnetic field so that the reset device closes the valve, and then (iv) actuation of the armature by energizing at least one electromagnet so that the Pump dispenses liquid.

The magnetically switchable valve can preferably be switched by reversing the polarity of at least one of the electromagnets. When reversing the polarity, there is no change in position of the armature relative to the electromagnet, since the force of attraction between the electromagnet and the armature is independent of the polarity of the electromagnet. In particular when the magnetically switchable valve is attached to the armature, which is a preferred embodiment of the invention, the valve body is influenced by the magnetic field of at least one of the electromagnets, in particular both electromagnets. Depending on the polarity of the magnetic field of the corresponding electromagnet, the magnetic valve body is brought into the open position or the closed position. In other words, the valve is designed to change its open state from the open position to the closed position and / or from the closed position to the open position.

It is advantageous if the magnetic valve body is permanently magnetic. This results in a particularly strong closing force of the valve.

The armature preferably has a shaft which is ferromagnetic.

The valve body is preferably designed in such a way that it rotates by at least 1 ° when the valve is closed and / or opened. This has the advantage that the valve body and the valve seat wear uniformly with respect to a radial component. In this way, the tightness of the valve is guaranteed, even if it wears out.

According to a preferred embodiment, the pump has at least one permanent magnet which is arranged such that the armature is held in its rest position, even when the electromagnets are not energized. The at least one permanent magnet is preferably arranged between the electromagnets.

For example, the valve body has a structured jacket surface. Thus, according to a preferred embodiment, the surface of the lateral surface can have grooves, grooves or recesses which extend along curves, in particular lines, which do not run parallel to a valve body longitudinal axis of the valve body. When the valve body moves along its longitudinal axis, a torque acting on the valve body is produced.

Alternatively or additionally, the valve body can have an inclined end face which is asymmetrical with respect to a radial component and which results in a torque acting on the valve body when the valve body moves along its longitudinal axis of the valve body.

According to a preferred embodiment, the pump has a first magnetic field shaping element which is arranged to shape a first magnetic field of the first electromagnet. It is favorable if the first magnetic field shaping element is arranged at least partially, preferably completely, radially inside the first electromagnet.

Preferably, the pump also has a second magnetic field shaping element which is arranged for shaping a second magnetic field of the second electromagnet. It is favorable if the second magnetic field shaping element is arranged at least partially radially inside the second electromagnet. The magnetic field shaping elements are designed in such a way that the armature can be positioned by energizing the electromagnets, in particular can be positioned steplessly.

The magnetic field shaping elements are preferably designed in such a way that they have an air gap. An air gap is understood to be an area in which the magnetic field is at most a tenth as strong as on the other side of the air gap. The air gap leads to an inhomogeneity of the magnetic field, so that the reluctance depends on the position of the armature along its armature longitudinal axis. In particular, it is not necessary for the air gap to be formed by air. Instead of an air gap, the term ferromagnet-free zone could also be used.

The magnetic field shaping elements are preferably designed such that a movement of the armature in the direction of its armature longitudinal axis in one direction increases the reluctance with respect to the first electromagnet, but reduces a second reluctance with respect to the second electromagnet. Depending on the strength of the electric current flowing through the first electromagnet or the second electromagnet, the result is a position of the armature with respect to its armature longitudinal axis which minimizes the reluctance. In this way, the position of the armature can be continuously adjusted by the current intensities through the first electromagnet and / or the second electromagnet

Furthermore, the anchor can preferably be so pronounced that it has at least three anchor elements. These are arranged in such a way that the armature can be positioned along its armature longitudinal axis by alternately energizing the first electromagnet and the second electromagnet.

In this case, the control is preferably designed to automatically carry out a method in which a first armature segment is initially positioned adjacent to a ferromagnet-free zone of the second electromagnet by energizing the second electromagnet, and as a result a second armature segment is in the effective area of the ferromagnet-free zone of the first electromagnet.

Then the second armature element is positioned adjacent to the ferromagnet-free zone of the first electromagnet by energizing the first electromagnet and as a result a third armature segment is in the effective area of the ferromagnet-free zone of the second electromagnet. Thereafter, the third armature segment is positioned adjacent to the ferromagnet-free zone of the first electromagnet by energizing the first electromagnet, with a fourth armature segment consequently being in the effective area of the ferromagnet-free zone of the first electromagnet.

In other words, the electromagnets are energized alternately and the armature segments are arranged in such a way that each time the energized electromagnet changes, the armature moves a predetermined path along its armature longitudinal axis.

Depending on the strength of the electric current flowing through the first electromagnet or the second electromagnet, the result is a position of the armature with respect to its armature longitudinal axis which minimizes the reluctance. In this way, the position of the armature can be continuously adjusted by the current intensities through the first electromagnet and / or the second electromagnet.

Depending on the strength of the electric current flowing through the first electromagnet or the second electromagnet, the result is a position of the armature with respect to its armature longitudinal axis which minimizes the reluctance. In this way, the position of the armature can be continuously adjusted by the current intensities through the first electromagnet and / or the second electromagnet.

It should be noted that the armature can of course only be continuously positioned within a predetermined interval.

The position sensor is preferably a magnetic sensor which has a magnet attached to the armature and a magnetic field sensor element. The magnetic field sensor element is preferably attached to the shaft of the armature. A distance between the magnetic field sensor element and the electromagnet is preferably selected to be so large that the magnetic field of the electromagnet does not significantly influence the position measurement of the position sensor. A magnetic sensor is understood to mean, in particular, a sensor that measures a magnetic field strength and uses it to determine the position of the armature relative to the cylinder. The magnetic sensor preferably contains a processor and a digital memory in which calibration data are stored, on the basis of which the processor determines the position from the measured magnetic field strength. These calibration data are determined, for example, in preliminary tests.

In a second embodiment of the armature position detection, the position of the armature is determined by measuring the inductance of the magnet coils, which is dependent on the position of the armature.

In a third embodiment of the armature position detection, the position of the armature is determined by measuring the flux density that is dependent on the position of the armature.

It is favorable if the feed line has an inflow opening for liquids to flow in from the cylinder interior.

The pump preferably has a controller which is designed to automatically carry out a method with the steps of (i) detecting a target stroke of the armature, (ii) continuously measuring an actual stroke, (iii) energizing the first electromagnet so that the Actual stroke approaches the target stroke and the liquid flows into the pump chamber and (iv) then energizes the second electromagnet so that the liquid is pumped out of the pump chamber through the dispensing opening. Because the actual stroke is adapted to the target stroke, the amount of liquid that is pumped through the dispensing opening per pump stroke can be set with high accuracy.

The controller is preferably designed to automatically carry out a method with the following step: After energizing the first electromagnet, so that the actual stroke approaches the target stroke and liquid flows into the pump chamber, and before energizing the second electromagnet, reversing the polarity of one of the electromagnets so that the valve closes. This has the advantage that immediately after the armature begins to move, the pumping space is reduced in size and liquid is dispensed through the dispensing opening. If, for example, a check valve were used whose valve body is not spring-loaded, the pressure in the pump chamber would first have to rise in order to press the valve body against the valve seat. During this time, an unknown amount of liquid can flow past the valve body. It is therefore not clear what amount of liquid per Armature stroke is actually delivered. This is avoided by the switchable valve.

The control is preferably designed to automatically carry out a method with the following steps: After pumping the liquid from the pump chamber through the dispensing opening, energizing the second electromagnet so that the armature is in its rest position. In other words, the pump chamber is minimally filled with liquid in the rest position of the armature. The rest position is the position in which the anchor is for the majority of the time. It corresponds to a preferred embodiment that the armature is preloaded into its rest position, in particular by means of a spring.

It is favorable if at least one of the electromagnets is subjected to an electrical current which has a high-frequency component in such a way that the armature oscillates. This oscillation has an oscillation stroke which is smaller than the stroke of the armature for pumping, in particular a maximum of one tenth, preferably a maximum of one twentieth of the stroke. This oscillation prevents a seal, which is preferably present and which seals the armature against the pump chamber, from sticking. The breakaway force that is necessary to move the armature out of a position in which the armature has previously rested becomes small.

Furthermore, the arrangement can preferably be operated in such a way that the oscillation of the armature is used for the precise setting of the specified target stroke during the filling phase and then with maximum force by energizing the second electromagnet without armature oscillation, the liquid from the pump chamber through the dispensing opening with a defined force is pumped (pressure stroke).

It is favorable if the pump has a temperature detection device which is set up to detect a temperature measured value that correlates to a pump chamber temperature in the pump chamber. For example, the measured temperature value is a measured value that indicates the pump chamber temperature. The measured temperature value can be present, for example, as an electrical signal, but it is it is also possible for the temperature measured value to be, for example, an electrical resistance that changes with the pump chamber temperature. It is only important that an exceeding of a predetermined temperature threshold value can be detected. For example, the temperature detection device can be a temperature-dependent resistor. If this resistor is an NTC thermistor, if the resistance falls below a threshold, it can be concluded that the pump chamber temperature is above a pump chamber temperature threshold value.

The controller is preferably designed to energize a heating element and / or at least one of the electromagnets to increase the pump chamber temperature when the pump chamber temperature falls below a predetermined minimum pump chamber temperature. In this way, for example, freezing or crystallization of the liquid is avoided.

The pump preferably comprises a cooling device for cooling the pump chamber. It can be a Peltier element, for example. The controller is preferably set up to automatically cool the pump chamber when the pump chamber temperature exceeds a predetermined maximum pump chamber temperature.

According to the invention, an odorization system is also provided with (a) a target fluid line, in particular a gas line, for example a natural gas line, for a target fluid, in particular a gas, for example natural gas, and (b) a metering device for metering a liquid to the target fluid, with (c ) the metering device has a pump and a reservoir which contains the liquid.

The cylinder and / or the reservoir is preferably filled with odorant.

It is generally favorable if the pump chamber is arranged below the cylinder. Any gases that may develop in the pump chamber are hardly released from the pump chamber, but escape upwards, in particular into the cylinder.

The invention also relates to a cold disinfection system with (a) a target fluid line in the form of a liquid line and (b) a metering device in the form of a disinfection device for metering a liquid in the form of a disinfectant into the liquid line, with (c) the disinfection device having a pump and a Reservoir that contains the disinfectant.

In this case, the cylinder and / or the reservoir is preferably filled with disinfectant.

Figur 1

ein erfindungsgemäßes Zudosiersystem mit einer erfindungsgemäßen Pumpe zum Durchführen eines erfindungsgemäßen Verfahrens,

Figur 2

eine zweite Ausführungsform eines erfindungsgemäßen Zudosiersystems mit einer erfindungsgemäßen Pumpe,

Figur 3a

eine dritte Ausführungsform eines erfindungsgemäßen Zudosiersystems mit einer erfindungsgemäßen Pumpe,

Figur 3b

eine vierte Ausführungsform eines erfindungsgemäßen Zudosiersystems mit einer erfindungsgemäßen Pumpe,

Figur 4a

eine weitere Ausführungsform eines erfindungsgemäßen Zudosiersystems mit einer erfindungsgemäßen Pumpe mit einem segmentierten Anker,

Figur 4b

eine weitere Ausführungsform eines erfindungsgemäßen Zudosiersystems mit einer erfindungsgemäßen Pumpe, bei der zusätzlich zu den Elektromagneten Dauermagnete eingebaut sind, die so zwischen den beiden Magnetspulen positioniert sind, das ein magnetischer Fluss entsteht, auch wenn beide Magnetspulen nicht bestromt sind.

Figur 5a

zeigt einen Ventilkörper einer erfindungsgemäßen Pumpe gemäß einer ersten Ausführungsform,

Figur 5b

einen Ventilkörper einer erfindungsgemäßen Pumpe gemäß einer zweiten Ausführungsform und

Figur 6

eine weitere Ausführungsform einer erfindungsgemäßen Pumpe.

The invention is explained in more detail below with reference to the accompanying drawings. It shows

Figure 1

a metering system according to the invention with a pump according to the invention for carrying out a method according to the invention,

Figure 2

a second embodiment of a metering system according to the invention with a pump according to the invention,

Figure 3a

a third embodiment of a metering system according to the invention with a pump according to the invention,

Figure 3b

a fourth embodiment of a metering system according to the invention with a pump according to the invention,

Figure 4a

another embodiment of a metering system according to the invention with a pump according to the invention with a segmented armature,

Figure 4b

Another embodiment of a metering system according to the invention with a pump according to the invention, in which permanent magnets are installed in addition to the electromagnets, which are positioned between the two magnet coils so that a magnetic flux is created even when both magnet coils are not energized.

Figure 5a

shows a valve body of a pump according to the invention according to a first embodiment,

Figure 5b

a valve body of a pump according to the invention according to a second embodiment and

Figure 6

another embodiment of a pump according to the invention.

Figure 1 shows a metering system 10 according to the invention for metering a liquid 12 into a target fluid line 14 in which a target fluid 16 flows. The metering system 10 has a pump 18 which has a cylinder 20 which surrounds a cylinder interior 22.

An armature 26, which runs in the cylinder interior 22, is arranged in the cylinder interior 22. The armature 26 has an armature element 28 made of soft magnetic material, in the present case made of soft iron, and a shaft 30. An annular gap 34 is formed between the armature element 28 and an inner surface 32 of the cylinder 20. A clear width w of the annular gap 34 is, for example, between w = 0.1 mm and 1 mm. The anchor 26 can have connecting channels 35 which run along the anchor longitudinal axis L.

The cylinder interior 22 is connected to a reservoir 36 via a line 37 in which the liquid 12 is contained. The liquid 12 is, for example, an odorant or a cold disinfectant. The cylinder interior 22 is therefore filled with liquid 12.

The pump 18 has a first electromagnet 38 and a second electromagnet 40, which are arranged one behind the other with respect to an armature longitudinal axis L. By energizing the electromagnets 38, 40, the armature 26 can be positioned along the armature longitudinal axis L. This position is measured along an x-axis that runs along the anchor longitudinal axis L.

A magnet 42 is arranged on the shaft 30 and, together with a magnetic field sensor element 44, forms a position sensor 46. The position of the armature 26 can be determined by means of the position sensor 46. It is favorable if a measurement uncertainty when determining the positions of the armature 26 is at most 0.2 μm.

The pump 18 has a pump chamber 48, which can also be referred to as a pump chamber. The pump chamber 48 preferably has a volume of at most 100 milliliters. The pump chamber 48 is connected to the cylinder interior 22 via a feed line 50. A magnetically switchable valve 54, which is shown enlarged in the right partial image, is arranged at an outlet end 52.

The valve 54 has a valve seat 56 and a valve body 58 which is ferromagnetic. In the present case, the valve body 58 is magnetized. For example, the valve body 58 can be made of magnetized steel.

The pump chamber has a discharge opening 60 for discharging pumped liquid 12, for example to a nozzle 62.

The pump 18 has a first magnetic field shaping element 64 and a second magnetic field shaping element 66. The first magnetic field shaping element 64 is arranged for shaping a first magnetic field B ₁ , which is generated by energizing the first electromagnet 38.

The first magnetic field shaping element 64 adjoins a first air gap element 68 made of non-magnetic, non-magnetizable material, for example non-magnetic stainless steel. The air gap element 68 has the same effect as an air gap at the same point and causes an inhomogeneity of the first magnetic field B ₁ in its surroundings. For this purpose, the air gap element 68 has a thickness that decreases in the axial direction with respect to the armature longitudinal axis L.

The second magnetic field shaping element 66 adjoins a second air gap element 70 and acts like the first air gap element 68 for the second magnetic field B ₂ , which is built up by energizing the second electromagnet 40.

The electromagnets 38, 40 are connected to a controller 72, which is possibly connected to the position sensor 46. The pump 18 carries out the method according to the invention described below. If, for example, on the basis of an external signal that is transmitted to the controller 72, a specified volume flow V is requested, the controller 72 calculates a setpoint stroke H _{setpoint from this} and energizes the first electromagnet 38.

The armature 26 then moves along the armature longitudinal axis L towards the first electromagnet 38, since the reluctance is reduced in this way. In the in Figure 1 The embodiment shown moves the armature 26 upwards. As a result, a pressure p ₄₈ in the pump chamber 48 is reduced. As a result, liquid 12 flows out of the cylinder interior 22 through an inflow opening 76 of the feed line 50, into the feed line 50 and reaches the valve 54. The valve 54 is open, so that the liquid 12 flows into the pump chamber 48.

When the armature 26 moves, the position sensor 46 continuously measures the position x and regulates an electrical current I ₁ (t) through the first electromagnet 38 and the current I ₂ (t) through the second electromagnet 40 so that the armature 26 moves along a predetermined target trajectory X _target (t) moves.

If the armature 26 has reached its top dead center, that is to say the pumping chamber 48 is _{filled with a predetermined nominal volume V nominal} , the controller 72 reverses the polarity of the current I ₁ . As a result, the position x of the armature 26 does not change. In contrast, the magnetic field B _{54 changes} in the vicinity of the valve body 58, so that the latter moves towards its valve seat 56 and the valve 54 closes.

The controller 72 then energizes the second electromagnet 40 in such a way that the armature 26 moves in an opposite direction. The volume of the The pump chamber 48 thereby decreases and the liquid 12 flows under pressure through the dispensing opening 60.

This movement takes place again along the target trajectory X _target (t), so that the volume flow V which flows out of the pump chamber 48 corresponds to _{the specified target volume flow V target.} If the armature 26 is at its bottom dead center, so that no more liquid is dispensed and then a countermovement in the opposite direction occurs, the controller 72 reverses the polarity of the second electromagnet 40 so that the magnetic field B ₅₄ changes its direction and the valve body 58 changes its direction Valve seat 56 is lifted off. The controller 72 can have a digital memory 74 in which the corresponding program is stored.

The shaft 30 is sealed against the surrounding wall by means of a seal 78. In order to minimize the so-called stick-slip effect when moving the armature 26, the controller 72 energizes the first electromagnet 38 and / or the second electromagnet 40 so that the armature 26 performs an oscillating movement before the armature 26 is moved for pumping . As a result, there is no static friction between the seal and the shaft 30, but only sliding friction. However, it is also possible to operate the pump 18 without the armature 26 being oscillated.

If there is no requirement for liquid 12, the controller 72 brings the armature 26 into its rest position, in which the volume of the pump chamber 48 is minimal. This reduces any gas bubbles that could arise as liquid 12 evaporates. If gas bubbles nevertheless form, they can escape upwards through the feed line 50 and thus do not lead to a corruption of the volume flow V.

It is possible that the pump 18 in the shape of a thermometer, a temperature sensing device 80 which is connected to the controller 72 and is arranged for measuring a pump chamber temperature T ₄₈ 48. in the pump chamber falls below the pump room temperature T ₄₈ a predetermined pumping space minimum temperature T _{48, min} , the controller 72 controls the first electromagnet 38 and / or the second electromagnet 40 in such a way that the liquid 12 in the cylinder interior 22 is heated. For this purpose, the electromagnets 38, 40 are in thermal contact with the cylinder interior 22.

The pump 18 can have an outlet 82 through which the liquid 12 in the cylinder interior 22 can be lowered.

In Figure 1 the valve 54 is arranged as an extension of the shaft 30.

The two magnetic field shaping elements 64, 66 are arranged between two non-magnetic and non-magnetizable side parts 84, 86 with respect to the armature longitudinal axis L. The magnet 42 is radially surrounded by the second side part 86, so that the magnetic field of the first electromagnet 38 is as small as possible. The valve 54 is surrounded by the first side part 84, so that the magnetic field of the second electromagnet 40 is as weak as possible at this point. The shaft 30 is made of ferromagnetic material so that the magnetic field in the area of the valve body 58 can be changed by reversing the polarity of the first electromagnet 38 and / or the second electromagnet 40.

Figure 2 shows a second embodiment of a pump according to the invention, in which the valve 54 is arranged.

Figure 3a shows a further embodiment of a pump 18 according to the invention in which - unlike the embodiments according to FIGS Figures 1 and 2 - A direction of movement of the valve body 58 does not run along the armature longitudinal axis L, but transversely thereto.

Figure 3b FIG. 11 shows a further embodiment of a pump 18 according to the invention, in which the air gap elements 68, 70 are not as in the embodiments according to FIG Figures 1 , 2 and 3a are arranged adjacent to one another, but on opposite sides of the respective magnetic field shaping element 64 or 66. Figure 4a shows a further embodiment of a pump 18 according to the invention, in which the armature is so pronounced that it consists of several elements.

Figure 4b shows a further embodiment of a pump 18 according to the invention, in which permanent magnets are present in addition to the electromagnets, which are positioned between the two magnet coils so that a magnetic flux is created even when both magnet coils are not energized. This causes the pump to remain in a defined position when de-energized.

Figure 1 shows that the pump 18 can have a heating and / or cooling device 87 for cooling the pump chamber 48. In the present case, the heating and / or cooling device 87 is a Peltier element that is energized by the controller 72. Depending on the polarity of the current direction, the Peltier element heats or cools. It can therefore also be referred to as a heating element when it is operated in a heating manner.

Figure 4a shows an embodiment in which the anchor 26 has several anchor segments 88.j (here: j = 1, ..., 4). The controller 72 is designed to energize first the second electromagnet 40, so that a first armature segment 88.1 is positioned adjacent to the second air gap element 70, that is, in the ferromagnet-free zone. As a result, a second armature segment 88.2 stands adjacent to the first air gap element 68 and thus in the effective area of the ferromagnet-free zone.

The first electromagnet 38 is then energized, as a result of which the second armature element 88.2 is positioned adjacent to the first air gap element 68. As a result, a third anchor segment 88.3 is in the effective area of the second air gap element 70.

The third armature segment 88.3 is then positioned in the ferromagnet-free zone of the second air gap element 70, that is to say adjacent to it, by energizing the second electromagnet 40.

As a result, a fourth armature segment 88.4 is in the effective area of the ferromagnet-free zone of the first air gap element 68. If the armature 26 would comprise more armature segments, the alternating current flow could be continued until the last armature segment, which is required for the maximum stroke length, is positioned in the corresponding ferromagnet-free zone is.

Depending on the current strength I _{38 of} the electrical current flowing through the first electromagnet 38 and the current strength I _{40 of} the electrical current flowing through the second electromagnet 40, the result is a position of the armature 26 with respect to its armature longitudinal axis L, which is the Reluctance minimized. In this way, the position of the armature 26 can be continuously adjusted by the current intensities through the first electromagnet and / or the second electromagnet I ₃₈ , I _40.

Figure 4b shows a further embodiment of a pump 18 according to the invention, in which permanent magnets 90.1, 90.2 are arranged between the electromagnets 38, 40. The permanent magnets 90.1, 90.2 are positioned between the two electromagnets 38, 40 in such a way that a magnetic flux is created, even if both magnet coils are not energized. This has the effect that the pump 18 remains in a defined position in the de-energized state.

Figure 5a shows a valve body 58 which has a structured jacket surface 92. In the present case, the lateral surface 92 has recesses 94.i (i = 1, 2, ...) which extend along helical curves K1, K2, .... The curves K1, K2, .. run around the valve body longitudinal axis L of the valve body 58. When the valve body moves along its valve body longitudinal axis L, a torque acting on the valve body occurs and the valve body 58 rotates through an angle of rotation α.

Figure 5b shows an alternative valve body 58, the end face 96 of which has an asymmetrical, oblique structure 98. The view from above, which is shown in the upper part of the picture, shows that the structure 98 has a 180 ° rotational symmetry, which is preferred, but not necessary.

Figure 6 shows a further embodiment of a pump 18 according to the invention, in which the armature 26 is arranged between the first electromagnet 38 and the second electromagnet 40. This represents a preferred embodiment - regardless of other features of the pump 18 according to the present embodiment.

In addition, the air gap elements 68, 70 are at a distance from the armature longitudinal axis L which is greater than the inner radius of the electromagnets 38, 40 (that is to say of the coils). This represents - independently of other features of the pump 18 according to the present embodiment - a preferred configuration. According to a preferred embodiment, the distance from the armature longitudinal axis L is at least as large as the mean value of the inner radius and the outer radius of the electromagnets 38, 40 The advantage of this embodiment is the lower power loss of the electromagnets. The usually comparatively small winding diameter is also advantageous.

The pump 18 and the reservoir 36 form a metering device 100.

The target fluid line 14 can be, for example, a gas line, in particular a natural gas line. In this case, the metering device 100 is preferably designed as an odorizing device, in whose reservoir 36 a substance 102 to be metered in is contained in the form of an odorant 102. The odorant 102 can be, for example, tetrahydrothiophene, a mercaptan or a mixture of ethyl acrylate (over 50%), methyl acrylate and 2-ethyl-3-methylpyrazine. The entirety of gas line 14 and odorization device 100 forms an odorization system 104.

Alternatively, the target fluid line 14 can be a liquid line. In this case, the metering device 100 is preferably designed as a disinfection device. The substance 102 to be metered is in this case a disinfectant. <b> List of reference symbols: </b> 10 Metering system 64 first magnetic field shaping element 12th liquid 14th Target fluid line 66 second magnetic field shaping element 16 Target fluid 18th pump 68 first air gap element 20th cylinder 70 second air gap element 22nd Cylinder interior 72 control 26th anchor 74 digital storage 28 Anchor element 76 Inflow opening 78 poetry 30th shaft 32 Cylinder inner surface 80 thermometer 34 Annular gap 82 procedure 35 lower flow chamber 84 first side part 36 reservoir 86 second side part 37 management 87 Cooling device 38 first electromagnet 88 Anchor segment 40 second electromagnet 90 Permanent magnet 42 magnet 92 Outer surface 44 Magnetic field sensor element 94 Recess 46 Position sensor 96 Face 48 Pumping room 98 structure 50 Feed line 100 Dosing device, odorization device 52 Outlet end 54 Valve 102 Substance to be added: odorant, disinfectant 56 Valve seat 58 Valve body 104 Odorization system 60 Dispensing opening 62 jet α Rotation angle T48 Pump room temperature L. Anchor longitudinal axis w clear width B. Magnetic field V. Volume flow H Hub i Running index H _target Target stroke P. print I ₁ (t) electrical current X _target (t) Target trajectory t time T _{48, min} pump room minimum temperature V _target Target volume flow V _should Target volume

Claims (15)

Pump (18) for dosing a liquid (12), with (a) a cylinder (20) which has a cylinder interior (22), (b) an anchor (26) which - runs in the cylinder interior (22) and - is at least partially ferromagnetic, (c) a first electromagnet (38) and a second electromagnet (40) which together with the armature (26) form a reluctance linear motor by means of which the armature (26) can be moved in the cylinder (20), (d) a pump chamber (48), the - Can be enlarged and reduced by actuating the armature (26), - Is connected to a feed line (50) for filling with the liquid (12) to be pumped and - has a dispensing opening (60) for dispensing the pumped liquid (12), (e) wherein the feed line (50) has an, in particular magnetically, switchable valve (54),
characterized in that (f) the pump has a position sensor (46) for the contactless determination of an armature position of the armature (26) relative to the cylinder (20). Pump (18) according to Claim 1, characterized in that the feed line (50) runs through the armature (26) and connects the cylinder interior (22) with the pump chamber (48). Pump (18) according to one of the preceding claims, characterized in that (a) the magnetically switchable valve (54)
has a permanent magnetic valve body (58) and at least one of the electromagnets (38, 40) can be switched by reversing the polarity, and that (b) the armature (26) is ferromagnetic. Pump (18) according to claim 2, characterized in that the valve body (58) (a) is designed so that it rotates by at least 1 ° when closing and / or opening the valve (54) and (b) has a structured outer surface, in particular inclined grooves, and / or a guide element on an end surface of the valve body (58). Pump (18) according to one of the preceding claims, characterized by (A) a first magnetic field shaping element (64) which is arranged to shape a first magnetic field (B ₁ ) of the first electromagnet (38), and (b) a second magnetic field shaping element (66) which is arranged for shaping a second magnetic field (B ₂ ) of the second electromagnet (40), (c) the magnetic field shaping elements (64, 66) being designed in such a way that the armature (26) can be positioned, in particular steplessly, by energizing the electromagnets (38, 40). Pump (18) according to one of the preceding claims, characterized in that (A) the armature (26) has at least three armature segments (88) which are arranged in such a way that the armature (26) along its armature longitudinal axis (L ), in particular steplessly, can be positioned and that (b) the position sensor (46) (i) is a magnetic sensor which has a magnet (42) attached to the armature (26) and a magnetic field sensor element (44) or (ii) is designed to measure the inductance of at least one of the electromagnets (38, 40) and to determine the position of the armature (26) from the inductance or (iii) is designed to measure a magnetic flux density and to determine the position of the armature (26) from the magnetic flux density. Pump (18) according to one of the preceding claims, characterized in that the feed line (50) has an inflow opening (76) for the inflow of liquid (12) from the cylinder interior (22). Pump (18) according to one of the preceding claims, characterized by a controller (72) which is designed to automatically carry out a method with the following steps: (i) detecting a target stroke (H _target ) of the armature (26), (ii) continuously measuring an actual stroke, (iii) energizing the first electromagnet (38) so that the actual stroke _{approaches the target stroke (H target} ) and liquid (12) flows into the pump chamber (48), and (iv) then energizing the second electromagnet (40) so that the liquid (12) is pumped out of the pump chamber (48) through the dispensing opening (60). Pump (18) according to Claim 8, characterized in that the controller (72) is designed to automatically carry out a method with the following steps: (i) after energizing the first electromagnet (38), so that the actual stroke _{approaches the target stroke (H Soll} ) and liquid (12) flows into the pump chamber (48), and before energizing the second electromagnet (40) Reversing the polarity of one of the electromagnets (38, 40) so that the valve (54) closes and / or (ii) after pumping the liquid (12) out of the pump chamber (48) through the dispensing opening (60), energizing the second electromagnet (40) so that the armature (26) is in a rest position. Pump (18) according to one of the preceding claims, characterized by (A) a temperature detection device (80) which is set up to detect a temperature measurement _{value which correlates to a pump chamber temperature (T 48} ) in the pump chamber (48), (b) the controller (72) being designed to energize a heating element (87) and / or at least one of the electromagnets (38, 40) to increase the pump chamber temperature (T ₄₈ ) when the pump chamber temperature (T ₄₈ ) falls below a specified minimum pump room temperature (T _{48, min} ). Metering system (10) with (A) a target fluid line (14) for a target fluid (16) and (b) a metering device (100) for metering a liquid (12) into the target fluid (16),
characterized in that (c) the metering device (100) (i) a pump (18) according to one of the preceding claims and (ii) a reservoir (36) containing the liquid (12). Odorisation system (104) with (A) a gas line (14), in particular a natural gas line, and (b) an odorization device (100) for metering a liquid (12) in the form of an odorant (102) into the gas line (14),
characterized in that (c) the odorization device (100) (i) a pump (18) according to one of the preceding claims and (ii) a reservoir (36) containing the odorant (102). Cold sterilization system with (A) a liquid line (14) and (b) a disinfection device (100) for metering a disinfection agent (102) into the liquid line (14),
characterized in that (c) the disinfection device (i) a pump (18) according to any one of claims 1 to 10 and (ii) a reservoir (36) containing the disinfectant. Method for metering a liquid (12) into a target fluid line (14) by means of a pump (18) according to one of Claims 1 to 10, with the steps: (i) detecting a target stroke (H _target ) of an armature (26) of the pump (18), (ii) continuously measuring an actual stroke of the armature (26), (iii) energizing the first electromagnet (38) and / or the second electromagnet (40) so that the actual stroke _{approaches the target stroke (H target} ) and liquid (12) flows into the pump chamber (48), and (iv) then energizing the second electromagnet (40) so that the liquid (12) is pumped out of the pump chamber (48) through the dispensing opening (60). Method according to claim 14, characterized by the step:
after energizing the first electromagnet (38), so that the actual stroke _{approaches the target stroke (H Soll} ) and liquid (12) flows into the pump chamber (48), and before energizing the second electromagnet (40), one of the polarities is reversed Electromagnet (38, 40) so that the valve (54) closes.

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